Screen printing involves pressing paint onto the material to be printed through a stencil applied to a mesh. This is a very common printing method characterized by high quality transfer of an image to any material, including those inaccessible to all other types of printing, saturation, large thickness and stability of the ink layer, low productivity, big amount areas of application, including not only printing, but even electronics.

Screen printing technology

The printing form is a frame with a metal or polymer mesh stretched over it. The number of threads in the mesh depends on the characteristics of the work being performed and on the method of applying a stencil to it; on average, it is 50-150 threads per cm. The thickness of the paint layer depends on the thickness of the threads and the distance between them. At the origin of this method, silk stretched over a wooden frame was used as a mesh, which is why screen printing is also called silk-screen printing.

The image can be formed on the grid in a direct or indirect way.

• The direct method consists of applying a copy solution (colloidal polymer solution) to the mesh. The solution is then dried to form a light-sensitive, soluble copy layer. The image is exposed to it, while the blank areas harden, and the printing areas are subsequently washed out with water.
• The indirect method consists of applying an image to a special film material with a copy layer. The copy of the image is processed, the whitespace elements are hardened. The copy is then rolled onto the grid.
• The combined method is a combination of the two above. The image is applied to a mesh previously combined with copying material and copying solution. This allows you to create more circulation-resistant forms and achieve high print clarity.

Printing proceeds as follows: printed form installed on the form holder. The sealed material is installed in a horizontal position, its immobility is ensured by stops and vacuum. The paint is applied to the form, then with the movement of a squeegee it is pressed into the mesh, while the squeegee pushes through the mesh and simultaneously cuts off the remaining paint. The mold is then withdrawn and the sealed material is removed to dry.

The production of printed products using the screen method is carried out both manually and using special printing machines.

Areas of application of the silk-screen printing method

Silk-screen printing is used to print a variety of surfaces: paper, fabric, plastic, glass, metal. In addition, the stencil method allows you to print uneven surfaces. All this determines the use of silk-screen printing in a wide variety of industries.

Due to the high quality of image transfer and low cost when printing small runs, silk-screen printing is used in the production of representative printing products: printing business cards, postcards, folders, invitations, creating booklets with a circulation of 50 copies. and other things. In addition, silk-screen printing allows the use of inks, the use of which is difficult for digital printing, for example, metallized (gold, silver). For large runs, printing in gold and silver, as well as other colors from the Pantone palette, is carried out using the offset method, and small runs can be printed using silk-screen printing.

One of myselfSilk-screen printing, or silk-screen printing, is considered one of the most universal and ancient printing methods. With this story we continue the theme of printing on souvenirs.

The Large Encyclopedic Dictionary gives the following definition of silk-screen printing: “ reproduction of text and graphic images by pressing paint through the holes of a printing form (polymer, silk or copper mesh, coated in the blank areas with a protective layer) » . When preparing the mesh (stencil), its printing areas remain open, that is, they allow ink to pass through, and the areas corresponding to the gaps in the image are coated with a composition that is impermeable to ink. The thickness of the paint layer depends on the thickness of the mesh cells and can vary from the normal 10-12 microns to 500 or more with several rolling.

This is a universal technology for applying images to products made of paper, plastic, film, leather, glass, ceramics, fabric and even metal and stone. It is possible to work as per flat surfaces, and on curved forms of material. Therefore, naturally, silk-screen printing is very actively used for printing on souvenirs and advertising and image products: T-shirts, baseball caps, umbrellas, balls, computer mouse pads, flags, lighters, mugs, ashtrays, etc.

From the history of silk-screen printing

The term "silk-screen printing" (serigrafia) etymologically consists of two roots: seri (from Greek - silk) and grafia (from Greek -writing, image). That is the origin of the name refers to work related to silk decoration or creating images with it. Traditionally it is believed that silkscreen printing originated in China, as did almost all things whose exact origin is unknown.

Existing hypotheses about the Chinese origin of silk-screen printing are based on the fact that silk began to be produced in this country 1200 years before ad. However, silk was directly involved in the development print at least 2400 years later.

There is a version that Silkscreen printing originated near the Mediterranean Sea, in the area between Mesopotamia and Phenicia. Many coincidences indicate that inventors Silk-screen printing, which was then considered an art, was the Phoenicians.

This small Semitic people lived on a narrow strip of land located approximately in the territory of modern Lebanon between the 13th and 3rd centuries BC. AD, famous for his sea voyages . The Phoenicians went beyond the Strait of Gibraltar to the Canary Islands, north to Great Britain. In addition, they swam throughout the Mediterranean basin. The Phoenicians traded and used their coastal cities as ports for exports. goods own production and brought from other countries.

Archaeological finds and historical research show that f The Inicians extracted purple, a red substance for dyeing fabrics, from the secretion of the gland of a mollusk. His began to be used for dyeing clothes. The dyeing of the fabrics was not done by hand, but in an accelerated process. But how could the Phoenicians reproduce the repeating coloring of fabrics when at that time there was no information about the equipment that could allow this? Canassume that the Phoenicians or some neighboring people found a way to reproduce designs on fabric using technologies that, of course, have nothing in common Yu t with modern ones, but represent the birth of the “multiplication system”, the “image repetition” system. However, Chinese origin cannot be completely ruled out.

So the birth of silkscreen printing can be seen as the appearance technology based on the repetition of relatively simple patterns using special matrices, “stamps” onto which paint was rolled tampons made by us from various materials.

Hardly Liv silkscreen immediately a frame appeared , but one can assume a significant simplification of the process through primitive printing using a “stamp”.

Stamp printing, which had many disadvantages primarily due to the insufficient layer of pigment when used on thick and absorbent fabrics, has undergone a bunch of improvements in subsequent centuries.

Z A significant improvement in the method occurred around 1185-1333. in Kamakura city, that was then the capital of Japan. All types of art flourished in this city, including printing: samurai armor and horse decorations were decorated. At first, the usual stencil method was used for this. Then a brilliant innovation was invented: since the image reserve,obtained only by cutting out the material, did not hold the entire design together, the image was cut out and pasted onto a mesh consisting of threads made from human hair stretched over wooden frame. Thus, the image was held together in all its parts, and the presence of fine hair became invisible when a swab moistened with pigment was pressed against the fabric to be decorated.

Numerous examples of Japanese stencils made from hair or fine silk fabrics demonstrate how silkscreen printing has become increasingly accepted character traits, characteristic of this type of printing Nowadays.

In Europe, the spread of the method occurred mainly in England, as well as France, where Jean Patillon began producing wallpaper around 1750.

In the second half of the 18th century, this technology spread throughout the world. And especially in America, where silk-screen printing was used to decorate furniture, walls, fabrics and metal products.

Fabric for the “print frame”, previously made from hair, began to be made from silk threads and muslin, but with this fabric was still very difficult to work.

Big step forward was made in 1907 when a certain Simon from Manchester patented the process of screen printing through silk fabric.She guaranteed higher tension resistance, greater dimensional stability and the use of rubber rollers (hereinafter rubber squeegees) for applying paint. The invention was cataloged under the title Silk Screen Printing (printing with silk sieve).

So The name "silk-screen printing" is quite recent. However, silk-screen printing was not considered as a new embodiment of graphics, as a real printing process, but had an essentially subordinate position, was considered a secondary method, a special type of printing.The rapid introduction of the method into industry began during the First World War, when chain stores began to appear in the United States. Each chain had to have its own corporate style - signs, display windows, aprons, hats with corporate symbols. But all this was required in small quantities - 50, 200, in extreme cases, 1000 pieces. For traditional printing, circulation is unprofitable, but for silk screen printing -just right. This is how the silk screen printing niche emerged. The niche began to expand, capturing more and more new areas of application, the method was improved, and as a result it turned into an independent industry, perfectly positioned in the market. M The silk-screen printing method was used to print substrates of any kind, from fabrics to posters, from postcards to labels, even to license plates for cars.

Ukraine and post-Soviet countries

In the USSR until 1985 using screen printing, the tasks of finishing binding covers, printing books for the blind using the Braille method, and in the electronics industry - manufacturingprinted circuit boards and electronic circuits. The method was also used in the porcelain industry for decorating dishes, both by direct application of an image and by the decalcomania method. In other industries, screen printing was used usually for applying simple line images to various parts and products. A the souvenir we are interested in is The branding use of screen printing was most often manifested in the production of promotional products (posters, posters, etc.).The main supplier of printing inks was the Torzhok Printing Inks Plant (TZPK), the meshes were produced by the Rakhmanov Silk Factory. By 1985, they mastered the production of screen mesh with a density of up to 140 nit. /cm. The development of new materials, equipment and scientific research were actively carried out by the Kyiv branch of the All-Russian Scientific Research Institute of Printing, where a screen printing laboratory was organized in 1961. The results of theoretical research obtained in the 60-80s have not lost their relevance today. Have been developed different photosensitive compositions - film based on PVA and liquid photopolymerizing ones. Film layers were introduced into production at the Krasnoyarsk Chemical Plant. The photopolymerizing composition "Polyset" was prepared directly at enterprises and screen printing sites according to a special recipe. In some places it is still used today, despite the wide variety of ready-made copying compositions produced developed countries.

Thus, the domestic industry almost completely met the needs of screen printing of that time. The fall of the totalitarian regime led to two opposite processes at once. On the one hand, public demand for printed products, especially souvenirs and advertising, has increased. This was facilitated by the development of business, the integration of Ukraine into the global information space, and the growth of a multi-party political system. On the other hand, many state enterprises fell into disrepair. The Kiev branch ceased to be a branch of VNIIKPP, but turned into the Ukrainian Research Institute of Special Types of Printing. The range of screen printing materials produced by the domestic industry has been greatly reduced. Against the backdrop of collapse large enterprises Small-scale production began to appear and multiply, which satisfied the interest in silk-screen printing products. Screen printing is seen as a production that can be started at minimal cost. This served as an impetus for its development in new economic conditions. If previously souvenirs with branded symbols, T-shirts and baseball caps with the names of sports teams or rock groups were practically not produced in the USSR, then with the beginning of perestroika, many so-called cooperatives quickly saturated the market with products of this kind. True, the level of quality was quite low, but those entrepreneurs who saw the future sought to raise it.

With the emergence of new screen printing enterprises and the expansion of its areas of application, there is a need for consumables. And as a result, offers appeared from foreign manufacturers through dealers: by the mid-90s, many companies had opened offering consumables and equipment for screen printing from various manufacturers, for example, Italian materials and equipment Argon, Saati, Swiss materials Foteco, Sefar, German materials and equipment Marabu, Proll, Bochonow, English materials Sericol, Autotype, including, used equipment was actively sold.

Screen printing in our country is entering new level development. In many enterprises, manual machines are being replaced by more accurate and productive professional equipment. And yet today, despite the interest in more productive and accurate semi-automatic printing equipment, most enterprises still make do with manual ones. The share of automatic and semi-automatic machines in the structure of the screen printing equipment fleet in the post-Soviet space, according to various expert estimates, ranges from 10 to 30%. However, the opinion that the equipment fleet will develop in the direction of increasing the share of semi-automatic machines is unanimous. The vast majority of enterprises are small, with up to 20 employees, and according to some estimates - up to 10 people. Enterprises with a staff of 20 to 50 people account for up to 10% of their total number. Average monthly productive capacity Screen printing enterprises, according to experts, range from 100 to 250 thousand ink prints. At many enterprises and screen printing sites, the level of plate processes remains low. “Handicraft” methods of tensioning meshes on frames and exposing the copy layer are still used, which do not make it possible to achieve the optimal quality of printing forms and, as a consequence, the optimal quality of the finished product. In most cases, liquid copying compositions (emulsions) are used. They are applied manually by pouring from a squeegee cuvette. The use of capillary and cut-out films is extremely limited due to their high cost, although they are known - mainly films from Autotype and Foteco. Inks are used in a variety of types: solvent evaporation curing (the most common type of ink), water-based, UV-curing, plastisol (for printing on cotton fabrics). The most widely used paints are still those of the Torzhok plant (TZPK), the Italian company Agron and the English Sericol. Quality requirements are increasing every day against the backdrop of a general increase in the level of printing products. Many enterprises and screen printing sites employ not professional printers, but specialists from other industries, who often have not fully mastered all the intricacies of the technology. There is not enough literature from which to obtain the necessary information.

If, say, in the electronics industry the use of screen printing has noticeably decreased, then interest in its capabilities for applying images to the most different materials: textiles, plastics, metal, glass and ceramics, wood, various types of cardboard, etc. A large share of work (about 30% of the total volume) performed using the screen method at domestic enterprises is various types of textile printing. Most screen printing enterprises and sites are not limited to the production of any one type of product, but carry out work for several industries. Thus, many printing enterprises that produce various types of sheet products or carry out UV varnish finishing are also engaged in printing on textiles, and are also mastering various types of transfer printing.

The stock of stencil equipment is being updated, although not as quickly as we would like. Automatic and semi-automatic machines are still used only in large and less often in medium-sized enterprises. In small enterprises, manual, often home-made equipment predominates - no more than two or three machines. According to experts, the greatest prospects on the market in the coming years are high-precision semi-automatic screen printing machines of at least A3 format, which can replace manual machines. Overall, the industry expects an increase in equipment automation and therefore productivity. Production volumes will also grow over the next 10 years, and the level of quality, which is quite good at many enterprises, will continue to increase. According to experts, a major breakthrough is expected in the field of high-quality multicolor printing.

Applications, advantages and weaknesses

Screen printing is called one of the most versatile printing methods, and yet there is a classification of silk screen printing applications.

1. Small format screen printing. It includes everything that is flat printing on various substrates, especially on PVC, as well as on paper and cardboard, the printing format does not exceed 100x140 cm. This is printing of products for a wide variety of purposes.

2. Large format screen printing. Flat printing of formats larger than 100x140 cm.

3. Printing on small items . It is possible to decorate pens, lighters, key rings and other souvenirs. For printing on round objects, rotary semi-automatic machines are used. Here Very competition from pad printing is noticeable(see previous “Printing courier”) , although the silk-screened image counts more resistant to abrasion.

4. Textile printing (fabric printing) . This is printing on fabric in reels, on sections using tabletop printing techniques, mechanotextile, carpet machines, machines with rotating cylinders. ABOUT a vast industry related to textile industry. Textile printing is one of the diverse and important sectors of the economy of many countries.

5. Textile printing on finished products . Printing on finished products (T-shirts, small items). This is done using machines called "carousel machines".

6. Screen printing on signs and metals. Related to metal fabrication and processing, anodizing, sheet metal stamping, etching, roasting, etc.

7. Screen printing on glass. It is used in the automotive industry and in the production of electrical household appliances. There are also special cases of application that can be attributed to the advertising and souvenir sphere, for example, printing on glass products.

8. Screen printing on bottles. Widely used in cosmetics, pharmaceuticals and some other industries.

9. Printed circuit board industry. Includes everything that can be done today by screen printing in electronic circuit processing such as common use, and professional, multi-layer, conductive, etc.

10. Additional screen printing.

Covers all those applications, special, additional and specific, that are not included in the groups listed above.

As already noted, silk-screen printing is actively used in a variety of advertising and souvenir industries. Another interesting application since the twentieth century has been art(which, by the way, with a certain amount of cynicism, can also be considered as a type of “souvenir”). Silk-screen printing was introduced into art by representatives of pop art, famous amateurs industrial technologies- Andy Warhol, Roy Lichtenstein, Jasper Johns. Screen printing is mainly a democratization of the artistic process, a way to acquire the creation of your favorite artist without spending too much on it big money. Few people can afford to buy their favorite paintings. The ideal solution for fans of a particular artist may be a print that costs much less.

Boris Velsky, director, tells non-profit organization“Moscow Studio”: “We recently had unusual order. In the living room, one of the walls was made of huge metal plates. And they have a huge fish, trout, printed on them. Its length is thirteen and its height is three and a half meters. It was an unusually spectacular spectacle!”

Silk-screen printing looks very good on old metal, but the life of such an object, unfortunately, is short - the material quickly rusts and the image is lost. A solution to the problem can be the use of artificially aged metal, fixed in this state. Silk-screen printing looks especially impressive on fabric. With its help you can get curtains with prints of your favorite painting, designer bedspreads and draperies. Boris Velsky: “One of the most memorable orders of recent times is a library in country house. The room was draped with fabric with a print, and it looked like a tent for a colonel of the colonial army... We also recently built an apartment-yacht. The curtains and drapery on the ceiling were made in the shape of sails, and on them were drawings of ships." The current trend is silk-screen printed designer wallpaper, paper or silk.

Experts usually include the following characteristics among the advantages of silk-screen printing:

1. simplicity of the process;

2. equipment available at a relatively low price;

3. ability to print on materials various types, on almost any surface, even textured;

4. significant thickness of the applied paint and specific silk-screen brightness of the paints;

5. durability of printed materials due to the thick ink layer;

6. savings when printing relatively small and medium runs;

7. special solutions that are impossible or less effective when working with other printing methods, for example, phosphorescent, silver, translucent inks, glitters, scented images (!) and, at the same cost, better coating.

To summarize, the main advantage of silk-screen printing can be called versatility.

The main problem of silk-screen printing is the instability of tone during printing (the stencil wears out, stencils are changed every 2 hours). In addition, screen printing spreads in a completely random manner in the most disparate industries, as a result of which it could not be too industrialized. Hence the lack of generally required methods and “canons” of silk-screen printing, and the absence of large, as in offset, equipment manufacturers. Although the latter is not always a disadvantage.

Another negative of silk screen printing is problems with large print runs. It is physically impossible to quickly place a large order, because the paint used in screen printing is very thick and viscous. And even modern and fully automated production cannot significantly increase the speed of squeegee passage and paint drying (the latter process, by the way, requires considerable production space). With screen printing, the printing speed is several times lower than, for example, with offset printing. Print runs that are too large can therefore take an unacceptably long time to produce, while print runs that are too small can be unprofitable. Experts recommend using the screen printing method when producing products with a circulation of several hundred to five thousand copies.

Technical process and some basic properties of silk-screen printing

Briefly, the silk screen printing process looks like this: n and a wooden frame with stretched “silk” (nowadays they use polyester fabric) is coated with a special emulsion and dried. Then a photo form (film with a printed image) is placed on the frame. black and white image) Initially, films of four colors are output (CMYK - blue, red, yellow and black; if additional colors are needed, then films are needed for them). After color separation, stencils are prepared. Photoform illuminated under a special lamp.After illumination, the frame is washed with water, dried, resulting in the appearance of printed matrix. Matrix secure in a silk screen machine, paint is poured. N and the sealed product. The paint transfers to the material through a fine mesh, and a special knife (squeegee) must go over each print. After applying paint to the material, it should be dried. Prints with designs are laid out on special racks or hung on special hangers.

Often silkscreen perceive as a simple process in which it is enough to use a sieve cloth and pass the paint through it.

In reality, there are specifics to the screen printing process that make it unique. compared to, for example, making tea through a strainer or filtering sand . The principle by which the squeegee forces the paint through the screen cloth, achieving a uniform and controlled passage, counts Basically, the law of silk-screen printing: “The passage of paint through the opening of the mesh of the sieve fabric occurs in a controlled manner only when it is possible to achieve a thixotropic effect using a suitable squeegee with the correct pressure.”This means that only if there is a factor of viscosity variability, the silk-screen printing process can be carried out. It is enough to simply check the passage of other non-silk screen materials. It will immediately become noticeable that the process doesn't happen in the right way cells become clogged and the material does not smear after passing through.

So, what is thixotropy? “Thixotropy is the ability of a liquid to change its viscosity when stirred or heated and return to its original viscosity at rest when stirring ends and to the temperature before stirring.” Thixotropy is the process of forced change in silk-screen ink, which allows it to pass correctly from one side of the sieve fabric to the other in the printing block and accurately reproduce the printed image.

Viscosity is the amount of internal friction or resistance that adjacent layers of fluid encounter as they slide past each other. Viscosity is also incorrectly called« liquid density" or " the opposite of fluidity» . Viscosity is directly affected by temperature, which becomes of great importance in the silk-screen printing process. Viscosity is measured using viscometers, among which we mention the Engler viscometer, called by some the "Ford glass", and the Brookfield viscometer, most used in the field of paints.

The controlled variation of viscosity, which we will define as thixotropy, allows the paint to pass more easily through the cells of the sieve fabric of the screen form, or cliche, and also acts in such a way that the paint does not stick together the substrate and the screen form and they are easily separated from each other with considerable speed. If something goes wrong during the printing process, the substrate does not separate from the stencil form and remains glued to it by the paint.

The phenomenon due to which the paint, when passing through the cells of the sieve fabric, cannot completely separate from the stencil form and acts as an adhesive between the stencil form and the substrate, gluing them together, is called« sticking effect».

« Sticky effect» is found quite often and depends on many factors. It may appear if:

-the paint is too viscous or incorrectly diluted;

-the image is blurry and the paint extends beyond the edges of the gelatin, which is why, remaining on it, it is not completely removed and sticks the stencil form and the substrate together;

-the paint is too cold and the thixotropic effect does not occur;

-the printing speed is incorrect, perhaps too high;

-the paint thinner is inappropriate and makes it too sticky;

-the substrate is poorly adhered to the printing plane or the vacuum of the exhaust system for sheets has weak pressure;

-the sieve fabric is poorly tensioned, there are too few “Newtons” and very little return force;

-the squeegee is too rounded, causing the theoretical closing line to be too wide;

-environmental factors such as static electricity aggravate the defect.

Another thing - textile printing. Here The variability of thixotropy is not always achieved, but only in some cases, since it is not necessary to print with a high degree of image clarity. The fabric behaves like blotting paper, so the screen printing process is partial, without varying the viscosity.

Another important concept from professional silkscreen jargon-« paint coverage": it is her " the ability to prevent the color tone printed with this paint from being visible in the light" That is, if is printed white on black, then with good Only white color will be visible after coverage. If the black remains partially visible, the paint will not cover tightly. The concept of coverage associated with silkscreen inks is actually directly related to the concept of matte:"m The satin finish of paint is its property of not transmitting light rays through itself, it is the opposite of transparency».

Types of coatings applied by silk-screen printing.

Colored paints. Silk-screen printing allows you to apply colorful layers of varying thicknesses to the printed material, which depends on the structure of the mesh. In offset, the thickness of the ink layer can also be adjusted, but within small limits. Since the layer thickness in silk-screen printing is many times greater than in offset printing, the intensity of the ink on the print will be significantly higher. Moreover, as a rule, screen printing uses opaque inks, which means that it is easy, for example, to print with yellow ink on blue paper. Moreover, the yellow will remain yellow, and will not turn into a barely noticeable green, as it would be in offset printing.

Covering white. Very interesting graphic effects are obtained when using opaque white paint. You can, for example, put it on a dark base (tinted paper, gray cardboard, etc.), and print an image on top of it on a regular offset printing machine - naturally, after the silk-screen paint has dried. Opaque white is also available for offset printing, but it is still not possible to obtain such a quality coating, due to the fact that the ink layer in offset is 5-7 times thinner. No less interesting is the result of printing with opaque white on transparent plastic. For example, if you print a halftone image on plastic using offset, and apply a white covering ink with a stencil on top, you will get a bright, saturated image that looks through a layer of plastic. In this way, it is possible to produce, for example, transparent labels or advertising and information materials for point-of-sale design (POS materials).

Gold, silver, metallic paints. In principle, both gold and silver can be deposited using the conventional offset method. However, as already mentioned, due to the greater thickness of the ink layer in screen printing, the metallic effect is significantly higher. Moreover, it has been noticed that metallic paints applied by offset take longer to dry. Therefore, if efficiency is important, then metallization using a stencil may be a good solution.

Fluorescent paints. There are quite a few types of such paints, but only with the use of screen printing can you get a truly bright, rich, fluorescent image - again due to the greater thickness of the paint layer. Such paints are used for a variety of printed materials, including both quite ordinary and quite exotic: glass, metal, leather, wood, various plastics, etc., each of which has its own special paint formulations. This means that the number of options for these same types of paints is huge.

It may seem that due to the high intensity of screen inks and the large thickness of the paint layer, you can get a very rich and bright image, close to photographic, or halftone. This is absolutely not true. As a rule, silk-screen printing is not used for printing halftone images; here it is inferior to offset in all respects. The exception is cases when it is simply technologically impossible to use offset, for example, when printing on fabrics or vinyl. Therefore, it is more correct to use silk-screen printing for printing even dies, continuous printing, line printing without precise registration, etc. But it is best suited for finishing.

Among the special effects that can be achieved using silk screen printing, one of the most interesting is thermal rise. Used to add dimension to texts or logos. Text or other design elements are printed in one ink. Thermal lifting in full-color printing is done in such a way that the ink being processed should be the last in the process of being applied to the paper. For example, if it is necessary to give a slight relief to the waves when printing a seascape, thermal powder is added to the blue paint. The powder used in full-color printing must be colorless, otherwise color rendering may be impaired. Interesting effects can be achieved by mixing different types of thermal powder. For example, mixing blue process ink with clear and silver powders gives a metallic effect to the print. It is possible to use sealing with varnish followed by thermal lifting with colored powders. This technique is undesirable for texts typed in small sizes or in fonts with thin strokes. Thermal lifting techniques are applicable to both glossy and matte surfaces. Thermal lifting on temperature-sensitive films or PVC must be carried out with careful selection of the thermal exposure regime.

Organization of silk-screen production and main equipment

To organize production you will need quite elementary conditions:

Room 20-30 square meters (needs 220 V electricity and water);

Computer (you can buy inexpensive and install the Corel Draw program);

Laser black and white printer;

Screen printing machine ( to save money you can do on one's own);

Exposure chamber;

A cutter is desirable (it is better to buy);

Accessories (squeegee, cuvette, mesh, frames, dryers, paints and other chemicals).

In total, according to experts, initial costs should be about 15 thousand hryvnia plus working capital.The personnel of the enterprise working with silk-screen printing must n include two mandatory positions: designer (can be taken part-time) and printer (preferably two).

According to Russian printing researchers (unfortunately, such calculations were either not carried out in Ukraine or are simply unknown), for competent sales organization company will pay for itself in 1 month.

Printed equipment can be divided into four types, differing depending on the material on which the image is applied: machines for printing on flat and roll materials, cylindrical surfaces and textiles. Machines for printing on roll materials and cylindrical surfaces can only be automated. The remaining machines (for textiles and flat materials) are manual and automated.

Manual machines for flat materials and textiles are small-format, large-format and rotary. Small-format manual presses print on flat materials, the format of which does not exceed 40x60 centimeters, and up to 30 millimeters thick. Accordingly, large-format manual machines are capable of applying an image to material up to 100x140 format at the same thickness. Rotary-type printing presses are designed for textile printing.

Many manufacturers are starting to engage in silk-screen printing due to the low cost of equipment, since this is practically the only type of printing in which it is possible to use manual equipment. It costs much less than automatic and allows high-quality printing of small and medium runs, which are most often ordered. To obtain a drawing made using the silk-screen printing method, you must have printing, laboratory and auxiliary equipment. And several separate rooms.

The simplest machine looks rather poor, but even it can be used. Among its shortcomings are the lack of any adjustments, a vacuum suction, difficulty in combining colors, and the presence of play (the printing frame is wobbly, so it is not easy to print in several colors on it). The main advantage is the insignificant price of such a machine and the simplicity of its design.

Another level of machines is more convenient, although the adjustment is manual (combination). Counterweights ensure automatic frame lifting, making the printing process easier. Bearings ensure smooth running of the printing frame. There is no backlash. A production press typically used to print large runs in a small number of colors. Highest level- manual machines with micrometric registers. There can be either simple printed circuit units or ready-made machines with a vacuum table. Micrometric registers allow you to achieve precise adjustments for printing in the next color. You can print full color (as color photography) image. These machines print high-quality multi-color printed products.

An important parameter is the size of the printing surface of the table. For different types It is more convenient for products to use a machine of the appropriate format, this allows you to save on consumables.

Examples and short characteristics of some printing machines on flat surfaces.

The simplest desktop manual machine - MT-45A (Ming Tai). The machine can be used for fairly rough work, such as one- or two-color inscriptions for marking flat objects, one-color leaflets, etc. The in-plane adjustments are located on the printing plate.

Manual unit for screen printing - MT-50A (Ming Tai) Can be attached to any table. It is a plate into which two tripod stands are soldered, allowing the sliders of the frame mounting device to move up and down up to 10 cm. It has micrometric registers on the TPF mounting unit. The machine allows you to print small runs of boxed blanks, postcards, panels, book covers, as well as posters and posters.

Floor standing manual screen printing machine with vacuum table MT-50V (Ming Tai) used for sequential multicolor and full-color screen printing on sheet materials up to 50 mm thick (paper, cardboard, plastic, self-adhesive materials, tin, glass and any flat finished products up to 50 mm high). Structurally, all printing units of this machine are made of metal and consist of a printing mechanism with an adjustable counterweight and a vacuum table with a special plastic coating that is insensitive to moisture and polished with high precision to ensure uniform coverage of the printed sheet with ink. The micro-registers of the printing mechanism have fine and fine threads and are actuated by a gentle motion, allowing for very precise registration printing, sufficient for full color and photographic images. Having printed all prints in one color (before applying the next color) or finished multi-color printing, you cannot do without a rack for drying prints. Intended for professional use, such racks are equipped with shelves made of a special metal alloy that is resistant to moisture, and the design is optimally selected and combines the possibility of intensive air circulation and space saving.

Semi-automatic machine for printing on flat and cylindrical surfaces - model SCF-550(Technical Ind. Co). Machine productivity is up to 800 cycles/hour. With manual feeding, the machine can print up to 1000-1200 full-color prints per shift. The SCF-550 model is equipped with a printing table that is fixed in height. During the working cycle, contact of the frame with the product occurs due to the lowering of the printed circuit assembly onto the vacuum table at flat printing or to a device for synchronizing the rotation of the printed object with the horizontal movement of the stencil when printing along the cylinder.

The printing machine is equipped with a pneumatic drive with microprocessor control. All components are mounted on a rigid and vibration-resistant supporting frame.

Another example of a roll to roll flat screen printing machine is Labelmen PWS-310. The Labelmen PWS-310 machine can be single-color or two-color. The width of the roll of printed material is 310 mm, the printing format is up to 300 x 300 mm.

The screen printing form is neutral to the composition of paints and varnishes. It does not interact with them, either on the physical or chemical levels. This makes it possible to work with water-soluble paints, with alcohol-based and volatile solvent paints, with oil-based paints and with special paints having various additives for special effects (protective, heat-sensitive, fluorescent, phosphorescent, reflective, metallic, pearlescent and odor paints), which, like usually physically or chemically aggressive. The same can be said about the composition of varnishes. Roll feeding makes it possible to work both with very thin materials that have low rigidity and do not fit into sheet-fed machines, as well as with thick materials that can be wound onto a roll.

A flat printing form, a flat supporting surface and complete immobility of the printed material, the printing form and the supporting surface during ink transfer ensure high quality printing. The supply of the printed material is cyclical, with preliminary unwinding. During the ink transition, the printed material, the supporting surface and the form are immobilized. This makes it possible to work with very thin stretchy materials, obtain precise ink registration on the print and produce products with high print quality. Labelmen PWS-310 roll flat screen printing machines operate at speeds of up to 60 prints/min. A computer system for positioning the printed material according to a control mark and vacuum fixation ensures accurate alignment of inks on the print during reusable printing from roll to roll. It also promotes virtually waste-free printing.

Additionally, tunnel UV or IR dryers, a roll winding device for printing from roll to roll, sections for cutting, embossing, longitudinal cutting of the roll and cutting the roll into separate sheets can be installed in line with the screen roll machine. This makes it possible to obtain finished two-color advertising printed products in one working cycle of the machine, which makes the production of short-run two-color (multicolor, several runs) printed products cost-effective. Labelmen PWS-310 machines can also be used to apply one or two-color stencil images on prints printed by other printing methods, when working from roll to roll.

There are also more professional, semi-automatic machines for printing on sheet materials. They are equipped with a micro-registration system, a vacuum table, an automatic squeegee movement device, with the ability to attach a “Take off” system, that is, automatic removal of the sheet after printing for transportation to a drying device.

Such machines allow you to print large runs of calendars, brochures, art albums, posters, box cuts, posters, with full-color prints or UV varnishing, with a volumetric layer of paint available only to the screen printing method, finishing various types decorative varnishes and glitters, and the ability to print large formats at an affordable cost of equipment.

Printing machines cylindrical surfaces(bottles, mugs, glasses, accessories industrial equipment cylindrical shape, bottles, jars for the perfumery and cosmetics industry).

To apply a durable multi-color image to a mug, bottle or other object of a similar shape, the above-described semi-automatic screen machines of the SCF series are often used. To print on cylindrical and conical surfaces, the machine is equipped with equipment for printing on cylinders (fixing device), the forced rotation of which (and, consequently, the product) is synchronized with the movement of the printing form.

Print by textiles(T-shirts, T-shirts, jackets, baseball caps, work clothes, flags, pennants, that is, perhaps the “most souvenir” products).

The principle of screen printing on textiles is not much different from printing on other materials. But the printing itself, as a rule, is performed using the “wet on wet” method, that is, the second color of paint is applied to the first almost immediately, after a short drying of the top layer of the first print of paint (fixing). Due to this, and also due to the fact that inks for textile printing differ in their composition and properties from inks for graphic printing, the method of drying finished prints will also be different.

The simplest manual machine for printing on T-shirts, T-shirts, work clothes is an analogue of a machine MT-45A, with one printing unit, differing only in the type of printing table - it is designed so that clothes can be “put on” on a flat rectangular table. Unfortunately, the capabilities of such a machine are too limited. To obtain a machine for single- or multi-color printing with the ability to obtain high-quality prints, the number of printing tables is increased, as well as the number of printing sections so that the upper and lower tiers can rotate relative to each other, resembling a carousel. This way you can apply the second and subsequent layers of paint without removing the product from the table.

Very important factors to select a machine is the presence of the same microregistration of each section of the printing carousel, as well as the presence of high-quality catchers (devices for positioning the printing unit above the object table at the time of printing). An example of machines that meet these conditions is the carousel series Praktik production Aeroterm. These machines can be used to print on work clothes, sports bags, T-shirts, and T-shirts. The undeniable advantage of such models is their affordable price with high quality and reliability of these machines. The main consumers of such carousels are start-up advertising and production companies and small manufacturing enterprises.

The next level of professionalism are manual rotary machines of the series Printex (Aeroterm). Reliable rigid construction, high register accuracy and ergonomic design have made these machines leaders in their class. They are designed for multi-color and full-color printing on T-shirts, work clothes, scarves, cuts of various textiles, etc.

For companies specializing in the production of textiles or the production of large volumes of printed textile products, series carousel machines are more relevant Chameleon production M&R. Firstly, these machines have a three-level pyramid design, which allows four- and six-color models to be expanded to 10 colors if production needs arise. Secondly, the profile design of the supporting frame ensures maximum rigidity and lightness of the carousel during operation. Thirdly, all parts that bear significant dynamic loads are made of reinforced materials with increased wear resistance, and work tables made of aluminum alloy are covered with a layer of special rubber that is resistant to paint, solvents and heat. All this, as well as the increased accuracy of all adjustable mechanisms, will allow you to print a lot, with high quality, without stopping production for additional adjustments, settings and equipment repairs, and, therefore, increase the service life of the machine and get the expected profit.

Laboratory equipment in silk-screen printing is designed for the preparation of screen printing forms. It is a pneumatic copy frame, exposure device and exposure installation. Laboratory equipment is intended for the production and restoration of the main thing: screen printing form. Auxiliary equipment includes a drying trolley, an intermediate infrared dryer, and a doctor blade grinding machine. Ready-made prints are placed on the drying trolley; an intermediate infrared dryer is used to polymerize inks when printing on rotary presses.

Printing, manual and auxiliary equipment are the main equipment for silk-screen printing. But don’t forget about fan heaters and hydroguns, cutters, laminators, heat presses, foiling machines, booklet makers, staplers, consumables and equipment, as well as a fully equipped computer. However, owning manual equipment for silk-screen printing, as well as by professionals who, in turn, are proficient in screen printing technology, you can get high-quality products.

Technology in detail

We present to your attention detailed description technological process silk-screen printing and basic devices and materials, taking into account the recommendations of Russian specialist Andrey Barkov.

After preparing the photo form on the computer in the Corel Draw graphic editor, it needs to be printed on a special film for laser printers (it comes in two types: matte and glossy). You need to print it on a laser printer with a resolution of 600 dpi (or 1200 dpi). Another method is photo output; some printing houses provide such a service.

The next stage of the process is matrix production. A screen printing form (stencil, matrix, template) is a frame with mesh fabric stretched over it. The fabric is then coated with a light-sensitive substance and exposed along with a transparencies film. Places of the printing plate that were not covered with a transparencies do not dissolve in water and harden. And closed areas are washed with water. This stencil can be used several times, which is very convenient.

Important properties of a stencil for silk-screen printing are the number of cells and the diameter of the thread. For example, 120 threads per centimeter, the diameter of each thread is 34 microns. It is best when the number of threads per centimeter is larger and the diameter of the thread is smaller. Today, fabrics of up to 200 threads per centimeter are produced. These values ​​affect such important indicators as picture clarity, printing speed, and paint drying.

Mesh made of nylon (polyamide) fabric has been used for a long time because it has several attractive qualities: strength, good abrasion resistance, elasticity. These qualities make it possible to print using nylon fabric meshes on convex objects and use a variety of materials. There is a modified nylon fabric that has a lower elongation than regular nylon.

Monofilament meshes can be made from polyester fabric, a classic silkscreen material. Such meshes are wear-resistant and chemicals, and in addition, they have a number of qualities that are remarkable for silk-screen printing: smooth surface, low elongation, resistance to climate change. Monofilament meshes provide good paint penetration, reproduction of the smallest details, and dry quickly. There is also a modified polyester fabric that is used for stenciling - it is more durable and does not stretch. The market for stencil fabrics today is developing every day.

A special emulsion is applied to the frame with a mesh (“silk”). For these purposes, a squeegee cuvette is used. The emulsion is dried using a hair dryer.

Illumination is done as follows: glass is placed on the stand, and the frame is placed on top with the grid facing up, then the photoform is applied with toner to the emulsion (now it will become a mirror image), and glass is placed on top again. This combination is placed under a lamp, usually ultraviolet or halogen, for a few minutes. Next, use cold water to rinse the matrix and dry it again with a hairdryer. Small flaws are corrected with special retouching. The matrix is ​​fixed in the machine, paint is poured and pressed through the matrix onto the paper using a squeegee.

Having printed the required amount of products, you need to wash the frame with solvents and wash the squeegee. The matrix, if the order is completed in its entirety, needs to be washed off, and if in the future it is necessary to return to it, then it is saved.

The quality of the resulting product largely depends on squeegee, the figure shows the structure of this instrument. The rubber is clamped with bolts. The rubber should be squeegee type, it comes in different colors and hardness. Usually there are three types - soft, medium and hard. Soft is used mainly for printing on fabrics. Rigid for printing high-precision, high-quality printed products. Medium - for general printing, packaging, on round surfaces.

You can try replacing branded rubber with oil- and petrol-resistant rubber, but such savings can hardly be called profitable. If used correctly, the squeegee will last a long time, but the quality suffers when replaced.

Frame made from hardwood, aluminum and steel, usually in a parallelogram shape. The purpose of the frame is to hold the mesh fabric, and to hold it evenly. Wooden frames have been used before and are still used today. This is natural, because cost, weight and ductility make wood an indispensable material. In addition, there is a special technology for stretching the mesh onto the frame, which not all silk-screen printers have mastered.

And the tree allows anyone to fix the mesh themselves using staplers. Such “manual” labor does not provide very precise tension, however, it is often used in Ukraine, especially for small-format products.

Unfortunately, wood is not a strong enough material - it bends, curves and absorbs water - owners of wooden windows probably know this. However, and this is also known, if you coat wood with varnish, it will resist the harmful effects of water and solvent longer.

The advantage of aluminum for frame construction is that it is very light. This is an invaluable property, especially for large format frames. Also the aluminum frame can withstand great strength mesh tension. But aluminum is not without its drawbacks: the high cost of welding, high oxidation ability, and also problems with gluing the mesh.

Frames made of steel are much stronger than others, inexpensive, and durable. But steel weighs a lot and is susceptible to corrosion. The last drawback of steel can be combated by using stainless steel to make the frame. Such a frame, however, weighs even more than a steel frame, but is not subject to corrosion.

To ensure uniformity and optimal tension force of the mesh, as well as strict parallelism and perpendicularity of the arrangement of the threads relative to the frame, special devices for tensioning the mesh of the pneumatic type, for example the series Max Newton production M&R. Their action is based on the operation of pneumatic cylinders with grippers for securing the sieve. The control unit provides tension control in two directions. The grips are made with a special coating that prevents the fabric from slipping during operation. The model of such a device is selected depending on the maximum TPF format. The number of working pneumatic units will also depend on this.

However, in domestic silk-screen printing practice, frames made of steel and stainless steel are rarely used. We believe that this is facilitated by the fact that it is impossible to manually tension the mesh onto the steel frame. And since the practice of doing everything yourself is quite often used in our country, they prefer to use wood for making frames.

So, for the manufacture of frames of small formats it is better to use steel and wood. In the first case, because it weighs less, in the second - because it is crooked. For large format frames, aluminum is most suitable.

If you still practice " manual labor", it is better to make the frame in a tenon. Sometimes the corners of the frame are cut off. The frame needs to be sanded and varnished well with nitro varnish and drying oil several times, and then dried. The size of the frame should be 4-6 cm larger than the printed format on each side. A 4-5 cm spacing is made at the top and bottom.

Main characteristics sieves- his number. The number means the number of threads per square centimeter; the more there are, the thinner the sieve and smaller parts can be printed on such a sieve.

Typically, for printing printed products with high quality, sieve numbers from 120 to 160 are used. Coarser numbers are used for printing on cardboard, packaging 70-100. Numbers 40-80 are suitable for printing on fabrics with special plastisol inks.

Mechanical and pneumatic sieve tensioning systems are much more convenient than manual ones. Self-tensioning frames are also popular. The quality of the sieve tension on them is an order of magnitude better than manual tension. But the price of such systems is quite high.

To do everything manually, you need to tighten the sieve well on the frame; the quality of the print largely depends on the tension of the sieve. The easiest way to do this is with your hands, but the tension is uneven. A more convenient way is to use special forceps.

When pulling the sieve by hand, it is better to do it with two people. A piece of sieve with a 4-5 cm blade should be thoroughly soaked in warm water. It is laid out on top of the frame, stretched and one side of the sieve is secured to the frame using buttons, nails with a wide head or, better yet, staples from a construction stapler. The opposite edge of the sieve is clamped in the middle into tongs and, using the handles of the tongs as a lever, the sieve is pulled. Then it is secured again using buttons or a stapler. Pull the sieve with tongs and secure the entire side. It remains to repeat the procedure on the other two sides.

The frame is re-varnished with nitro varnish along with a sieve along the edges. In this case, care should be taken that the varnish does not get on the stretched surface of the sieve. After the varnish has dried, you can varnish it again to be safe.

Illumination process.

Most often, it uses two main illumination schemes: a lamp from above or a lamp from below. During exposure, those areas of the emulsion that receive light are hardened. And those that were under the toner (photo form - positive) are not duplicated. After exposure, these areas are easily washed off with water. And on the emulsion matrix there remains a reverse copy (inversion) of the photoform. When printing, paint is pressed through the washed holes. To obtain a high-quality matrix, it is necessary to press the photoform as tightly as possible to the emulsion layer. This is done either with clamps or using a vacuum clamp, which requires a compressor. As already mentioned, glass smaller than the frame is placed on the stand. Next comes the frame, printed side up. Now the photo form is placed on the printed side of the frame with a layer of emulsion applied. The photoform is placed with toner on the emulsion (when printed, the photoform is output as a regular sheet, without mirroring). A mirror image of the photoform appears on top. On top of the photo form is glass smaller than the frame. You need 2 glasses for each matrix size.

The glass edges should not be sharp, smooth. (so as not to damage the sieve). All that remains is to secure it all with clamps at all corners or at the diagonal corners of the frame. All that remains is to turn on the lamp.

When illuminated, the distance from the lamp to the frame with the photo form should be 1.5 diagonals of the photo form, the angle of incidence of the rays on the frame should not be more than 60 degrees. The illumination time can be determined manually with a stopwatch, or you can use a photo relay with a timer through which we connect the lamp.

For exposure, you can also use illumination chambers, which in their design resemble exposure chambers for illuminating polymers. Such chambers have a vacuum clamp and recesses around the perimeter to accommodate a stencil frame with a mesh. Depending on the format of the form, exposure chambers can be selected, e.g. NuArc production M&R, Ming Tai.

To correctly select the right exposure time, take a sheet of thick black paper. Several identical images are printed one below the other on a photo form; it is advisable that they also include small text. Secure the photo form to the frame using transparent tape. And with a felt-tip pen on the photo form next to each image they write the time: 2 minutes, 2.30; 3.00; 3.30; 4.00; 4.30; 5.00.

The frame is placed under the lamp and all but one part of the photo form is covered with a sheet of paper. Turn on the lamp for 2 minutes, then move the sheet of paper and open the next part. And the exposed one also needs to be covered with something. Turn on the lamp for 2 minutes 30 seconds. So, by moving this “window”, all parts are illuminated. For example, photoforms are illuminated from a distance of 55 cm for 4 minutes, 25 seconds with a halogen lamp power of 1.5 kW. AZOCOL POLY PLUS S-RX emulsions are used. So for other lamps and emulsion there will be different times. Exposure time also depends on the sieve number and the number of emulsion layers.

For matrix washing the container (this could be a bathtub) is filled with cold water to a depth of 10-20 cm. The frame with the illuminated emulsion is placed horizontally in the water. The water should completely cover the frame. The frame is rinsed, and after some time the unexposed areas of the emulsion are washed out, and the stencil gradually appears. Shake off the water from the matrix, and then, holding the frame horizontally, dry it with a hairdryer. If, after a long rinse, the matrix is ​​poorly washed (this means that the matrix has been overexposed, it will be necessary to reduce the exposure time), direct a stream of water under pressure to the unwashed areas, the text, without stopping the stream in one place, so as not to blur the stencil, and only from the inside framework. In this way, you can wash the crossed matrix.

If, when washing the frame in a container of water, the matrix is ​​completely washed off, or small details are blurred, then the frame is not illuminated with the emulsion. It will be necessary to increase the exposure time.

One of the advantages of silk-screen printing is the ability stencil regeneration, that is, they can be used several times. Once the stencil is no longer needed for one print run, it can be saved and used for another order. There is a technology for regenerating a stencil, which is based on removing the previous emulsion layer from it. Here it is necessary to make a reservation - successful regeneration of a screen printing form is possible only if the exposure is carried out in accordance with all the rules. Otherwise, it may be difficult to remove the old layer.

The process of stencil regeneration is inextricably linked with interaction with a wide variety of chemicals. Therefore, it is important for the silk screen printer to use safety glasses, gloves, and a respirator. So, to restore the stencil, you need to: clean the mesh of paint, remove the old emulsion layer and shadow images. It should be remembered that the stencil does not last forever: the paint is cleaned using solvents, which gradually corrode the mesh. Therefore, the stencil “wears out” over time and can be used a limited number of times.

Any housewife knows that cleaning a food stain or dish becomes easier the faster it is done. It's the same with paint in silk-screen printing. After printing is completed, the ink must be washed off the stencil immediately, or it will be almost impossible to do so after some time has passed. To clean the mesh from paint, special solvents are used. The old emulsion layer is removed using special oxidizing agents that soften it. These can be powders, tablets or ready-made solutions. Then the drug is evenly applied to the stencil and after a while it is washed off with strong water pressure.

Before we talk about removing shadow images, let's first define what shadow images actually are. The paint used in silk-screen printing contains pigments. When paint is applied to a stencil, these pigments penetrate the threads of the mesh stretched over the frame and color them. Then the grid turns out to be multi-colored. The resulting effect is called “shadow images”. Shadow images are removed, again, using special means. This process occurs in the following sequence: the stencil is moistened with an activator-cleaner and an alkaline paste is applied to it. After 10-30 minutes, the stencil is washed with a strong stream of water.

An important point - vacuum table device. Thick plexiglass (plexiglass), plastic or stainless steel is often used as the printing surface of the table. An important requirement for the surface: it must be smooth and flat, without bumps, swellings or crevices. Small holes of 1.5-2 mm are drilled across the entire surface of the table. The distance between them is 1.5-2 cm.

A rubber gasket or window insulation in the form of a hose is attached to the back of the table. A sheet of plexiglass or plastic with a hole for a suction cup is attached to the gasket. The gap between the table and the sheet of plastic should be from 0.5 to 1.5 cm. Air is pumped out of the gap, and air is sucked in through holes in the table. Thus, any sheet of paper sticks to the table and does not move. This allows for precise registration when printing in multiple colors.

You can increase the suction force by filling some of the holes with sheets of paper. And, conversely, if the suction is too strong, loosen it by removing the sheets from the holes. To create a vacuum suction cup, companies that sell equipment also offer compressors. You can also use an ordinary vacuum cleaner or fan for this. A vacuum suction cup is used for working on flatbed printing machines; it is not needed for printing on cylindrical surfaces or fabrics.

A little about photosensitive emulsions- they can be divided into four groups. Emulsions of the first group are resistant to solvent-based paints, but are “afraid” of water. Emulsions of the second group are resistant to water-based paints and plastisols. Emulsions of the third group are universal, and with the help of emulsions of the fourth group you can get a thicker layer of paint. To get a good stencil, you need the emulsion to cover the mesh evenly. 1-2 layers are placed on the printed side of the mesh, 1-4 layers of photo emulsion are placed on the squeegee side. Then the stencil is dried.

Although there are plenty of emulsions available commercially, some printers prefer to produce emulsions by hand. Most often, those who have problems with the supply or price of imported emulsions.

The main disadvantage of homemade emulsion is its short shelf life. The remaining shortcomings can be written off, since the cost of a homemade emulsion is 50 times lower than the branded emulsion.

To produce an emulsion in artisanal conditions, you need: gelatin about 2 cubic meters. see also ammonium bichromate (NH4)2CR2O7, in common parlance “chrompic”. Gelatin granules are placed in a two-hundred-gram glass glass and half filled with cold water. Gelatin swells in a couple of hours. Meanwhile, “chrompic” is dissolved in a glass of water (50 g) until a saturated solution is obtained.

The next step: you need to completely dissolve the gelatin in water. To do this, pour water into a saucepan, place a glass of gelatin in it and heat it, stirring so that the gelatin dissolves.

The resulting brew and the bright orange “sauce” must be thoroughly mixed. This should be done in a dark room under a red lamp.

The prepared emulsion is stored in the dark for no more than a week. It is applied to the frame, like a regular emulsion, with a squeegee cuvette, but in the dark under a red lamp. The lighting process is the same. The matrix is ​​washed with slightly warm water. After printing, a caustic soda solution is used to wash off the unnecessary matrix and clean the sieve for the next one.

There is another recipe. The emulsion created using it can be stored for a longer time:

1. Gelatin, 50 g.

2. Ammonium dichromate (NH4)2CR2O7, 6 g.

3. Ammonia 10%, 20ml.

4. Citric acid, 3 g.

5. Water, 80-100 g.

Retouching the matrix for printing in one color is not too difficult. In the light of the matrix, in addition to the design, small holes-breakdowns in the emulsion layer will be noticeable in places. They need to be retouched. For these purposes, a special retouch (for example, KIWOFILLER) is best suited. All these holes are covered with retouch, using a match or a brush, and then dried with a hairdryer. Retouching for printing printed products is resistant to solvents, but is easily dissolved and washed off with water. Using retouching, you can print from one matrix in several colors. First, one color on the matrix is ​​covered with retouching and the other is left open. After, having printed the required edition, the color covered by the retouch is washed off with water, and the printed one is covered over. Then the second color is printed from the same matrix, thereby saving emulsion; instead of two or three matrices, one is produced.

It is not recommended to save and replace retouching; it is used very sparingly and lasts for a year or more. And yet, some people replace retouching with nitro varnish (washed off with acetone) or PVA-type glue, resistant to solvents but soluble in water.

For preparing the frame for printing You need wide tape and thick paper. Having installed the frame in the grips of the machine, you need to pour paint into it. And then paint will be pressed through the areas open from retouching and emulsion. The paint can flow freely along the edges of the matrix; these gaps are covered with tape. Although many experts advise covering all edges with retouch, using tape is much more economical.

Before installing the frame into the grips, you can simply line the inside corners of the frame with tape. When using a small matrix or 2-3 matrices on one frame, part of the inside of the frame can be covered with thick paper, secured along the edge with tape. However, having printed the desired color, you will have to tear off the tape, clean the frame and seal it with tape again.

Sometimes you can print several colors from one frame by simply separating them with cardboard dividers and tape. Having printed one color, it is simply sealed on the printed side with tape and paint is poured into the adjacent cell, printing the next color.

Let's consider paints for printing printed products. Stencil paints have high viscosity and strong covering power. A huge advantage of silk-screen printing is the ability to use a wide variety of printing inks. In silk-screen printing you can print with glossy and matte inks, print with gold, silver, print with white ink or clear varnish. Using this technology, you can achieve a wide variety of decorative effects that are not available when printing on printers.

The ink for silk-screen printing should be thick, like good sour cream or mayonnaise. Another quality indicator: the paint should be rich, well pigmented, and opaque.

The most famous specialized screen printing ink has the abbreviation TNPF(Stencil), produced in Torzhok, Russia, it is known throughout the CIS. At some point the plant was falling apart and producing virtually no paint; now the crisis has passed. More accurate technical information can be found on the factory website. The plant also produces special paints for glass, metal, and plastic. Standard prices range from $5 to $20 per kg.

Organic solvent inks from companies are also used for printing. Sericol(England), Marabu(Germany) and Apollo(England). The company's paints are suitable for working with “difficult surfaces”. RUCO. These paints were found wide application in the design of bottles and jars for cosmetics, plastic bottles for household chemicals, machine oils, gasoline, as well as packaging for food products. They are represented by 15 basic colors, a raster set (cyan, yellow, magenta and black) plus gold and silver. Mixing system RUCOLOR 2" allows you to obtain any shade from basic colors according to generally accepted catalogs Pantone.

Instead of special screen paint, you can use offset paint. You need to add varnish to it, since the paint is matte and takes quite a long time to dry.

Special paints can also be replaced with ordinary alkyd enamels, which can be purchased at any hardware store with good choice colors. Unfortunately, most enamels are too liquid to print, so you have to work with them.

First recipe. Place the open can of paint on low heat and cook, stirring occasionally, for 15-20 minutes. Until the condition is like that of thin jelly, bubbles will float to the surface but will not burst immediately. You need to try it in small containers first. And with experience comes an intuitive feeling when the paint is ready. Cooking the paint improves pigmentation and evaporates the varnish. Another observation: when the paint cools, it becomes much thicker than when it cooks.

The cooled ink is ready for printing. If it is too thick, dilute it with enamel solvent, kerosene or white spirit.

Second recipe. You need to drive water into ordinary liquid enamel, then the enamel becomes thicker. Thus, from one can of enamel, you can make two. The paint must be used immediately - after standing for a while, the water will begin to separate from the enamel.

How to get matte from glossy paint? A soap solution is driven into the glossy enamel. To turn matte into glossy, you need to add alkyd varnish.

When for printing process everything is ready, the frame with the matrix is ​​fixed in the grips of the machine. Now you need to set up the frame. The distance from the lowered frame to the sealed product should be about 3-5 mm. It is important that the printing press has the ability to adjust this distance. A little paint is poured into the frame.

The squeegee is picked up and the paint is rolled towards you. The pressure should be uniform, the movement should be smooth, but not slow. The squeegee is held at an angle. The idea of ​​printing is simple: with a squeegee, grab a little paint and push it through the matrix onto the surface to be printed, paper, self-adhesive, cardboard. Then the printed sheet (or other object) is removed, a new one is placed, and the same sequence of actions is repeated.

There are two printing options: with roll and without roll. With rolling, before printing, each time a layer of ink is rolled onto the matrix with a raised frame. This allows you to get a thicker layer of paint on the product. Used for printing with light inks on dark papers and cardboards. Without rolling, they print directly onto the product without rolling ink. The lines are thinner, which means the paint layer is thinner. This is how high-precision orders and full color are printed more often.

There are also two ways to apply images. The first is contact, the second is non-contact. Non-contact is used very rarely - when using it, the material does not touch the mesh, and the paint is transferred from the mold using electrostatic forces. In the contact method, accordingly, the mesh is in contact with the printed material, and the ink is supplied with a squeegee.

If during printing the matrix suddenly begins to float, it must be wiped with a cloth with a solvent, then with a dry cloth. Sometimes, if the image is blurry, you need to change the distance between the frame and the table.

Problems that arise during printing often require small changes: change the pressure on the squeegee, change the angle of the squeegee, change the distance between the frame and the table, strengthen the vacuum suction. You can master the printing process in half an hour, the rest comes with experience.

Sheet base and color combination. To print large quantities accurately, even in one color, it is necessary to fix the printed sheet in the right place, and place each subsequent one in exactly the same place. This place is called the "base". Usually an angle is used to create a base. The corner is made from sheets of thick paper and attached to the printing table using tape or PVA glue. Then each subsequent sheet is placed exactly in this corner, which allows you to achieve equally good registration on large runs. The corner is laid out on a precisely aligned sheet. If the surface of the printing table is made of plexiglass, that is, transparent, it is adjusted to light. A lamp is installed under the table, a vacuum suction is turned on, a sheet is placed on the table, the frame with the matrix is ​​lowered and the desired alignment is achieved in the light. The frame is lifted and a corner of thick paper is glued out without removing the sheet or turning off the suction cup. Other colors can be adjusted in the same way.

If the table top is opaque, you will need a sheet of thick transparent film - film for photo output or photo forms is ideal. We need to secure one side of the film with tape, so that the main part of it is strictly under the frame with the matrix. After this, paint is poured and printed directly on the film, the vacuum suction is turned on and the sheet is adjusted according to the image printed on the film. Then the base corner is secured to the sheet. The following colors are adjusted in the same way.

The convenience of micrometric registers on the machine makes the registration process easier. Here you just need to tweak the settings a little and continue typing. And there is no need to re-glue the base corner.

To make it easier to combine colors, it is convenient to use adjustment marks for printing accuracy. They are placed on a color separated photo plate in the corners of the image. Now, in order for one color to “hit” another, you need to combine the risks. It is problematic to combine colors without marks when printing full-color or multi-color images.

Such is the general outline, silk screen printing. A method that is clearly most aimed at medium and small businesses, and also combines well with other types of printing. However, even such a universal and original technology does not exhaust the topic of souvenir printing.

You can leave your opinion about the article you read

Attention! It is prohibited to include links to other sites in your message!

Screen printing or silk-screen printing at home is a method of applying a design to different surfaces by pressing paint through a special mesh. The technology involves transferring images to fabrics, stationery, dishes, plastic bags etc. No super complex manipulations or expensive equipment is needed.

Doing silk-screen printing at home is beneficial because it:

• handmade (always relevant and valuable);
• there are no restrictions on the types of images;
• brightness and colorfulness of the picture;
• wide selection of materials - paper, plastic, fabric;
• low cost;
• simplicity of technology;
• compactness - no need for a separate room and bulky equipment.

Screen printing devices take up minimal space

Screen printing mesh

The quality of silk-screen printing depends on the printing form, namely on its base (mesh). It happens:

• Polyester. Used when printing with water-based, plastisol, solvent inks. The type of weaving also differs: canvas (1:1 - one thread to another) and twill (2:1 or 2:2). The former are used more often.
• Steel. Only used when working with thermoplastic paints.

The nets are available in white and yellow. The latter provide maximum clarity of the picture with detailed detail.

White and yellow screen printing grids

Pay attention to the lineature. It is present in the labeling. For example, marking on the grid “No. 120-34” means that the size of the lineature is 120 lines per centimeter, and 34 is the diameter of the thread. The higher the first parameter, the finer the mesh.

Mesh fabric is divided into categories depending on the thickness of the threads. Each category is designated by its own letter (stands next to the number: S, M, T, HD - from light to heaviest). Fabric with a thick thread is stronger, it is pulled with greater effort. The thickness of the thread affects how much paint will pass through the mesh.

When working with a thick canvas, the edges of the design lose their clarity. Jagged edges may appear. Choose thin grids for small images.

Silk screen frame

Stencil frames are used not only in printing houses, but also at home. They are subject to the following requirements:

• reusability - in order to reduce the cost of printing;
• chemical resistance - when washing and applying a photosensitive layer and paint, contact with the frame is inevitable;
• rigidity - frames are made of rigid material that is resistant to torsion and bending deformation;
• light weight - the frame should be light and mobile.

The simplest stencil frames for silk-screen printing are made with your own hands from straight-layer wood. They are light, cheap, but sensitive to moisture.

The alternative is aluminum. It is inexpensive, lightweight, and allows you to achieve the required tension. The aluminum frame is not susceptible to the chemical effects of reagents used in silk-screen printing, is suitable for repeated use, and retains its geometry.

Ready-to-use wooden frames

Stencil without exposure and emulsion

Another way to make stencils for silk-screen printing is using a heat press. It was developed by the Americans. Will be needed laser printer. Start by printing the desired image on regular xerox or offset paper. Print in black and white.

Now place the printout face down on the prepared transfer paper and send it to the heat press. It will take 20 seconds. at a temperature of 110 ०С - the image from the printout will be transferred to transfer paper.

It should be placed face down on the frame and put back into the heat press. This stage lasts half a minute. Working temperature- 180 ०С. The stencil is ready.

This is what a heat press looks like

Drawing on fabric

You will need a mesh, frame and paint. If you have artistic talent, the drawing is created using a brush; if you don’t, it is created on a computer. For beginners in silk-screen printing, we recommend starting with large solid images, that is, without small details and complex geometry.

Step 1. Selecting an image. The design for screen printing at home can be anything: a logo, a picture, an inscription. It is drawn or found on the Internet and then printed on a printer.

Step 2. You can take a ready-made frame with a mesh or stretch it yourself, securing the edges with a construction stapler. You need to additionally glue them with paper tape or electrical tape - the paint will not spread.

Step 3. The frame is covered with photo emulsion. This is a light-sensitive composition - a dark room will be required. It is applied from top to bottom, carefully working through each area. The frame is allowed to dry in a horizontal position - approximately 1-3 hours (time depends on the thickness of the layer).

Step 4. The dried mesh is covered with a piece of dark fabric. This is anti-light protection. The frame with the mesh is placed on a stand, with its front side facing the light source.

Step 5. The next stage of silk-screen printing at home is preparing a sample for printing. Take the image as you want to transfer it to the product, turn it over and place it on the frame.

Step 6. Now you will need transparent glass - with its help the drawing is pressed to the mesh. You can turn on the light. For a 60x60 cm grid, it will take an average of 35 minutes with a 150 W lamp located 45 cm away from the image. After this, a barely noticeable imprint appears on the stencil.

Step 7 The stencil design must be lightproof. To verify this, look at it by pointing it at a light source. If the rays penetrate the picture, the quality will be poor. You will need to print another copy and overlay it on top of the first. Another option is to color over the sample with a marker.

Step 8 Now you need to rinse the frame with warm water. As the photographic emulsion is washed away, the print will become more and more pronounced - the stencil is ready.

Step 9 The prepared stencil is placed on the product. The outside of the frame with the mesh should be in contact with the work surface. If it is fabric, for convenience, put something hard and flat under the bottom.

Place paint on the stencil and distribute it evenly using a rubber scraper. The harder you press on the scraper, the clearer the pattern will be. It should be taken into account that when the paint dries, it will take on a darker shade.

Step 10 The finished product is dried. To fix the image, the fabric is ironed.

The paint should not destroy the stencil material. Choose one that dries no faster than the printing process.

The picture is bright and full color

The process of silk-screen printing on fabric is shown in the video:

Results

• Silk-screen printing on fabric is possible at home: it is simple and inexpensive.
• The technology is used to create unique T-shirts, souvenirs, pens, pillows, and mugs.
• You can create a stencil with your own hands; all you need is fabric, mesh, frame and paint.
• Modern technologies make it possible to create stencils without emulsion and exposure.

Silkscreen printing

(Practical guide by silk-screen printing)

Silkscreen printing- this is a printing method in which paint is applied using a mesh made of silk, nylon or other material, resulting in a convex pattern on surfaces of various shapes and materials.

Nowadays, silk-screen printing is used everywhere. With its help, logos and branding are applied to souvenirs, designs on textiles and paper, plastic and fabrics, business cards and labels, envelopes and folders, forms and booklets are made.

Silkscreen printing- a universal printing technology, it allows you to print an image of any number of colors (the number of grids must be equal to the number of colors in the picture), on materials of almost any type, shape and size. You can print on plastic, paper, cardboard, glass, fabrics and textiles - on anything.

The art of silk-screen printing dates back to ancient times. The very name “silkscreen printing” ( serigrafia ) comes from Greek seri (silk) and graffia (writing, image). Apparently, either the first screen printing meshes were made of silk, or this printing technology was originally intended for applying images to silk fabrics. That is why it is traditionally believed that the birthplace of silk-screen printing is China (in China, silk production began 1200 years BC). But there is no confirmation of this assumption. Moreover, some scientists believe that silk-screen printing could not have originated in China in principle, since silk was involved in this printing technology almost two and a half millennia later.

There is a hypothesis that places the homeland of silk-screen printing closer to the Mediterranean Sea, in the area between Mesopotamia and Phenicia. And even more specifically - to Phenicia (the territory of modern Lebanon).

More than one silk-screen printing seems to be “hanging in the air”, without having documented roots - neither the place of birth of this technology is known, nor is there what modern inventors call analogues and stereotypes (that is, what was the forerunner of the technology, on what basis it arose - unclear). The same mysterious achievements include some monuments of disappeared cultures - pyramids and drawings in the ancient Mayan cities, the remains of the culture of the indigenous population of Taiwan, and so on.

Silk-screen printing is as much a fairy tale as the strange drawings of the Mayans and Taiwanese. The emergence of technology raises questions among historians, but various industries use it without much thought. Moreover, modern technology silkscreen printing has nothing in common with the original one. It only indicated the possibility of a kind of multiplying system for repeating images.

The closest to the modern art of silk-screen printing are the methods of decorating samurai armor, used in Japan in the years 1185-1333. So every time you pick up a T-shirt decorated using the silk-screen printing method, you can consider it the vestment of a modern warrior. And at the same time, reflect on the frailty of everything earthly and the inevitable transformation: from the armor of samurai, the elite warriors of Japan, to ordinary cotton T-shirts.

The practical guide is compiled based on the publications of Andrei Barkov, Zakhar Akulov, Artyom Nasonov, Pavel Kuragin, Nikolai Litvinov, as well as books and magazines on Printing and Silk Screen Printing.

Silkscreen technology. The information below should not be considered as a direct guide to action. The information is an overview, the main task— to convey a certain minimum to those who have no idea what silk-screen printing / screen printing is.

Since there are many in the technological chain key points, we strongly recommend that you carefully study the literature on this topic and consult with suppliers of equipment and materials.

Silkscreen technology. Screen printing form

Silk-screen printing technology involves, first of all, the production of a screen printing form. For production, as a rule, aluminum rigid frames are used.

Roller frames and wooden frames are used much less frequently. The first is due to its relative high cost, and the second, wooden frames are the most economical option, but not the best.

Using tension devices, a special mesh made of polyester or stainless steel is stretched, then the mesh, in a stretched state, is glued to the frame.

The video shows the process of tensioning the mesh on a high-quality tensioning device SAATI TOP12.

There are also simpler and cheaper mechanical tensioning devices. Some printers use roller frames as tensioning devices, although they are not intended for this. If they are used for their intended purpose, then there is no need for a separate tension device and glue.

On video: the process of tensioning the mesh on a roller frame

After the mesh is stretched and glued to the frame, using substances that fall under common name“chemistry”, the mesh is roughened and degreased.

We apply a photosensitive layer - these are photoemulsions or capillary films.

Photo emulsion is poured into a squeegee cuvette and applied on both sides of the mesh.

In the video: applying the emulsion using a squeegee cuvette.

In the photo: drying cabinet for screen printing forms

When the stencil section is heavily loaded, drying cabinets are used, which accommodate several racks.

The next stage of screen printing technology (silk-screen printing) is exposure. Exposure of color separated films occurs in exposure devices with vacuum clamping, usually using the contact method.

In the photo: exposure device with a point light source

After exposure - development. Unexposed areas of the photo layer dissolve in water, while exposed areas remain on the grid. Development takes place on stands that are backlit and do not allow splashing.

The video shows the process of preparing the mesh before applying photo emulsion, applying photo emulsion, drying, exposure and development.

The screen printing form is ready. Number of printing plates = number of films = number of inks with which the design will be printed. It should be noted that in most cases, the stencil can be removed from the mesh and the photo layer can be applied again - i.e. make a new stencil (the process is called “regeneration”).

In the photo: this is what the stencil looks like when enlarged

Due to the characteristics of the equipment used, printing is divided into textile and graphic.

Silkscreen technology. Textile screen printing

Printing takes place on rotary presses. Printing plates are attached to the printheads, and T-shirts are placed on the tables. The paint is pressed through the stencil using a squeegee. Using manual machines, we print the first color on all T-shirts placed on the tables, then the second color, etc. On automatic machines, printing occurs simultaneously on all print heads.

In the photo: manual carousel machine for printing on T-shirts

When really good productivity is required, automatic textile rotary looms are used.

In the photo: automatic carousel machine for printing on T-shirts

In the direction of rotation of the tables, an intermediate dryer is installed - “drying”. On manual machine it is placed in such a way as to dry the ink on one table while the printer prints on another. It is used when not printing “wet-on-wet”, that is, almost always. On automatic machine It is installed, as a rule, instead of the print head.

In the photo: intermediate dryers - “dryers” are used for multi-color printing

After the final color is printed, the T-shirt is removed from the table and passed through a tunnel conveyor dryer for final drying. If productivity is not needed, then for final drying you can use an intermediate dryer (plus: noticeable cost savings, minus: significant loss of productivity - several times).

Silkscreen technology. Graphic screen printing

The classic version is a machine with one printing form and a table that provides vacuum clamping of the product / sheet materials. Multicolor printing is carried out sequentially: we print the first color on a certain run, dry it, change the printing plate, print the next color, etc.

Semi-automatic screen printing machine

Depending on the paints used, different types of dryers are used. UV dryers are used for drying paints, varnishes and other UV-curing materials

Conveyor UV dryer

IR conveyor dryer with air circulation in a tunnel - a high-performance alternative to a stack dryer (pictured: Turbo JetStar dryer)

A pile dryer is an economical option for working with solvent paints

Instead of a conclusion

Each type of equipment listed above has different options both in design features and characteristics, and in price. Therefore, first of all, you need to decide on the tasks. At a minimum this is:

Type of printing (textile or graphic)
Maximum print size
Maximum number of colors/paints
Maximum productivity (e.g. prints/hour, T-shirts/shift, etc.)
Are you planning on full color printing?

For more information, see the FAQ section, as well as other sections of our website.

home » How to earn » Screen printing technology from A to Z. Screen printing. Small format screen printing