silkscreen

The forerunner of screen printing is the Japanese template. 1890.

Silk-screen printing is a kind of screen printing, in which special polyester, polyamide (nylon) or metal meshes with a frequency of 4-200 threads / cm and a thickness of about 18-200 microns are used as a form material. Typically, gap elements are formed directly on the grid by a photochemical method. For the manufacture of a printing plate, both a dry film photo layer (capillary film) and a liquid photographic emulsion dried on a grid after application can be used. In the normal state, the photolayer is washed off with water. In the vast majority of cases, exposure is carried out by contact. After exposure to UV radiation, the photolayer polymerizes and ceases to be washed off with water, with the exception of areas that have not been exposed to radiation (covered by the image of the positive). Washed out sections of the grid become printing elements.

Printing with appropriate inks can be carried out on almost all materials - paper, plastic, PVC, glass, ceramics, metals, fabrics, leather, etc. Inks can differ in the type of binder - water-based, solvent (solvent-based), UV curing, plastisols (requiring temperature fixation - thermal shock).

Silk screen printing is also used for printing decals (transfer pictures on glass or ceramics) with or without subsequent firing, for applying an erasable (“scratch”) layer for lottery tickets and payment cards.

This method got its name "silk-screen printing" because of the patent of the screen printing process, issued in 1907 under the name of English. silk screen printing- “printing with a silk sieve”. It is believed that this printing method originated in ancient times, but screen printing acquired its modern look in the middle of the last century. Thanks to the peculiarities of the technology, silk screen printing allows you to print on both flat and cylindrical surfaces. Now screen printing is used not only in printing, but also in textile, electronic, automotive, glass, ceramic and other industries.

One of the features of screen printing is the ability to obtain a thick ink layer from 8 - 10 microns to 1000 or more (for offset, the ink layer is 1-2 microns) with impressive hiding power and color brightness. You can also widely use special effects - glitters (sequins), three-dimensional printing, imitation of velvet or rubber. It is possible both direct printing directly on the printed surface, and transfer (transfer) on an intermediate carrier (eg transfer paper) with subsequent transfer to the product.

Silkscreen in art

If at an early stage of its development, until about the beginning of the 1990s, silk-screen printing was used mainly for industrial and commercial purposes, today it occupies one of the leading places among other methods of creating visual art.

In the past century, silk-screen printing has become widespread and used not only as a method of making copies in applied arts, industrial design, when creating facsimile reproductions or in the field of large-scale printing, but also as one of the self-sufficient types of author's printed graphics - printmaking, which has pronounced qualities and capabilities of its own plastic language. Today silk-screen printing is included in the lexicon of artists of all directions, in various types (graphics, painting, sculpture) and genres of fine art.

In the twentieth century, such dissimilar masters as Willy Baumeister and Takesada Matsutani, Kosuke Kimura and Timur Novikov, Harry Gottlieb and Richard Hamilton, Marcel Duchamp and Andy Warhol, Robert Rauschenberg and Fernand Léger, Jackson Pollock and Jasper Johns turned to silk-screen printing. Ben Shahn and Roy Lichtenstein, Will Barnet and Adolph Gottlieb, Jim Dine and Robert Indiana, Claes Oldenburg and Tom Wesselman, Robert Maderuel and Jimmy Ernst, Stuart Davis, Victor Vasarely and many more.

Usually this type of screen printing is called serigraphy. In Russian, the history and specificity of this type of silk-screen printing is covered in detail in the books by Alexei Parygin “Silk-screen printing as an art” (2009) and “The art of silk-screen printing. XX century" (2010).

Scope of screen printing

Screen printing is one of the most technologically advanced printing methods. It covers the most various areas applications: from handmade to high-tech industrial solutions, from the smallest formats in the manufacture of printed circuit boards to the largest posters of the order of 3x6 m and from single copies to large print runs, measured in tens of thousands. The screen printing method prints paper, textiles, ceramics and synthetic materials in the form of a web, individual sheets, as well as products for various purposes and shapes, such as cans, glasses, dashboards, latex balloons.

Color palettes are characterized by great diversity. Special paints are widely used for a wide variety of areas. In the stencil method for printing illustrations, four-color (full-color) printing is widely used. Apparatuses, machines and devices used for screen printing cover both ordinary fixtures and installations used in handicraft production, and large machines for work on an industrial scale.

For screen printing, there are practically no restrictions on the dimensions of the print, this explains the demand for large-format silk screen printing, where the size of the image is measured in meters. The screen printing method is used for printing on large-sized products, such as aircraft fuselages and other Vehicle. In the small printing area, the print may have image elements of up to 0.2 mm or less, for example, a printed circuit board pattern for microelectronic devices.

Screen printing has other specific applications. For example, applying glue through a special stencil made with a laser to the contact pads of printed circuit boards for the purpose of subsequent fastening of radio elements, printing with electrically conductive and phosphor pastes in order to obtain luminous panels for technical applications and advertising, applying an image to chocolate bars, and many, many others. Areas of use.

Literature

• Parygin A. B. Silkscreen art. XX century (history, phenomenology, techniques, names). - St. Petersburg. : SPb GUTD, 2010. - 304 p. - ISBN 978-5-7937-0490-8
• Parygin A. B. Silkscreen as an art. Technique, history, phenomenology, artists. - St. Petersburg. : SPb GUTD, 2009. - 261 p. - ISBN 978-5-7937-0397-0
• Averyanov VV Screen printing: A practical guide to screen printing. - M.: Gamma, 1998 - 109 p., ill.

see also

Links

Wikimedia Foundation. 2010 .

Books

• The banknote industry: modern technologies and recommendations

Basic components of screen printing.

Stencil. In screen printing, the form is - a stencil, which is a mesh on which the mesh is stretched. A photographic emulsion is applied. A positive (photo output) is superimposed on the photographic emulsion. With the help of an ultraviolet light source, the emulsion is illuminated. Those parts of the photographic emulsion where the light hit harden, and where it didn’t hit, they are washed out. In the process of printing, ink is forced onto the product through the sections of the grid free from photographic emulsion, as a result of which a printed image is obtained.

A squeegee is a device that is a rubber spatula with which the paint is pressed through the stencil mesh.

Forrakel is a device that is a metal spatula with which the ink returns to the beginning of the print.

Screen printing theory.

Basic conditions for quality printing.

1. Ensure contact between the emulsion layer on the printed side and the surface of the printed product along the entire length.

To ensure this condition, the following parameters are met. Squeegee pressure force. The magnitude of this force must be sufficient to ensure good contact between the photo emulsion of the grid and the printed material along the line of contact. The force is calculated per 1 cm of doctor blade, therefore, the longer the doctor blade, the more force must be applied to ensure good contact. The greater the squeegee pressure, the better the contact, but the higher the wear of the mesh and squeegee blade. Excessive pressure can cause the doctor blade to flex a lot, resulting in a reduction in print angle and an increase in ink dosage. Many printers mistakenly believe that the harder you press, the better the ink will come out.

To obtain optimal contact along the line of contact of the squeegee with the printed surface, the pressure force should be 10-15% more than the force that is sufficient to contact the table.

2. Ensure uniform dosing of paint. Forcing the required amount of ink through the stencil during printing (moving the squeegee) over the entire area.

Printing angle (the angle between the colorful plane of the squeegee and the grid). Changing this angle changes the amount of paint pushed through the mesh. The smaller the print angle, the more ink can be pushed through the mesh. With a very small printing angle, an overdose of ink occurs, which can cause the print to float LUBRICATE FORWARD. With a large one, on the contrary, the fill will not be dense enough. At an angle greater than 90°, the amount of paint pushed through the mesh is theoretically equal to zero. The optimal printing angle is 75°.

Print speed. We must try to keep the maximum print speed to ensure the performance of the printing area. The speed is affected by the viscosity of the paint. The higher the viscosity, the lower the printing speed and the higher the likelihood of the squeegee floating on the ink. Therefore, you need to set more squeegee pressure.

3. Ensure that the sieve is separated from the paint immediately after the squeegee passes.

Print gap (distance between the grid and the printed material). When this distance changes, the force of separation of the grid from the printed material changes. The larger the printing gap, the smaller the separation angle and the greater the force that tears the mesh from the ink. But as the print gap increases, the print angle also decreases.

Tear-off angle (the angle between the mesh and the printed material behind the squeegee). When this angle is changed, the force of separation of the grid from the printed material changes. The smaller the separation angle, the greater the force that tears the mesh from the paint. At an angle of 180°, the tearing force is zero. In addition to the angle, the tearing force depends on the tension force of the mesh on the frame. Therefore, the more the mesh is stretched, the greater the force at the same separation angles.

Separation zone (distance between the line of contact of the squeegee with the sieve and the line of separation of the mesh from the printed material). The size of the separation zone directly depends on the magnitude of the separation force. The larger the printing gap, the smaller the tear-off angle and the greater the force that tears the mesh from the ink, which means that the tear-off zone will decrease, which reduces the likelihood of smearing the print LUBRICATE BACK.

Grid tear force. The magnitude of this force must be sufficient to ensure a quick separation of the grid after passing the squeegee. As mentioned above, the tearing force directly depends on the mesh tension force. The greater the tension force, the greater the tearing force at large tearing angles, which means that you can set a smaller printing gap.

4. Ensure uniform spraying of the paint.

The return of the ink occurs with the help of a squeegee (in manual printing, its function is performed by a squeegee). In the forrakel, as well as in the squeegee, there is an angle between the sieve and the colorful plane. The size of this angle determines how much to push the forrakel of the paint into the sieve when it returns to its original position.

There are 2 types of forrakels: Spatulas, (Angle up to 90 degrees) they are designed for printing with viscous inks and press more ink into the sieve and Scoops. These squeegees have an angle greater than 90 degrees and are designed for liquid (low viscosity) inks such as UV and UV varnish. When using spatulas, the paint is transferred to its initial position, as it were.

Irrigation must be adjusted so that the ink evenly covers the surface of the printed image, but does not leak onto the printed side. If the ink does not cover the printed image, there may be a misprint or an uneven layer on the print. When ink flows onto the printed surface (liquid inks), it is smeared, usually forward.

5. Avoid smearing when printing.

When printing images, a vertical force is applied to the stencil screen through the squeegee (to ensure contact between the printed surface of the screen and the printed substrate) and a horizontal force to move the squeegee. When the squeegee moves, a friction force arises between the squeegee and the mesh, and since any sieve tends to stretch, the image on the mesh under the influence of force shifts in the direction of the squeegee movement. After the squeegee makes a printing stroke, forces are removed from it, which leads to the disappearance of the friction force and the grid returns to its original position. In this case, the lubrication of the colorful edge occurs. The more viscous the paint, the greater the pressure force on the squeegee, the weaker the tension of the sieve and the greater the coefficient of stretching of the mesh, the greater the amount of smear.

To reduce smearing:

It is necessary to reduce the pressure of the squeegee,

If possible, reduce the viscosity of the paint.

Types of screen printing.

1. The initial state.

a. The stencil is up.

b.

c.

2.

a.

b.

c.

3.

a. The squeegee moves to the end of the image.

b.

c.

4. Raising the squeegee and stencil.

a. The squeegee rises from the grid.

b.

5. Lowering the forrakel.

a.

6.

a.

b.

c. Printing completed.

As a result, we see how the paint is pressed through the mesh onto a flat product using a squeegee.

Disadvantages:

Impossibility of printing on a curved surface.

Slow print speed compared to offset printing.

Large amount of paint.

Advantages:

Ability to print very large formats at low cost.

High covering power of a paint layer.

Printable products - this method can be printed on almost any product that has a flat shape. Textile products (t-shirts, sweatshirts, windbreakers, jackets, overalls, bathrobes). Sheet material (paper, cardboard, self-adhesive, folders, business cards, envelopes, letterheads, posters, boxes, sheet plastic - plates, light boxes, sheet metal- signs, signs, panels, sheet glass - stained-glass windows, light boxes, furniture doors, laminated chipboard - furniture doors, banner fabric - flags, streamers, posters).

The basic principle of circular printing is that during the printing process, the product rolls along the stencil, and the squeegee pushes the paint onto it.

1. The initial state.

a. The stencil is up.

b. The paint is thrown on the stencil mesh (there is paint in the mesh image).

c. The product is set for printing.

2. Lowering the stencil and squeegee.

a. The stencil is lowered to the product.

b. The squeegee is lowered to contact with the product.

c. The stencil mesh comes into contact with the product.

3. Moving the squeegee, pushing the paint onto the product.

a. The product roll on the stencil.

b. The paint is brought into contact with the product using a squeegee.

c. The stencil mesh comes into contact with the product.

d. Excess paint is removed from the mesh with a squeegee.

4. Raising the squeegee and stencil.

a. The squeegee rises from the grid.

b. The stencil rises from the product.

5. Lowering the forrakel.

a. Forrakel descends to contact with the grid.

6. Moving the forrakel to the beginning of the image.

a. Forrakel moves to the beginning of the image.

b. The paint is applied in an even layer to the open areas of the grid, filling them.

c. Printing completed.

Disadvantages:

The impossibility of printing on products with a large taper (more than 3-4 degrees).

Large amount of paint.

It is not possible to print mugs from handle to handle.

Advantages:

High hiding power.

Large print area compared to pad printing.

The possibility of applying a very high paint layer.

The possibility of reusable stencil, the photomulsion can be washed off and a new image can be obtained again.

Low stencil production costs.

Printable products - this method can be printed on almost any product that has the shape of a cylinder with a small cone. To do this, the product must have sufficient rigidity. Dishes (mugs, glasses, glasses, bottles, ashtrays, thermoses). Packaging (jars, bottles, tubes, cardboard tubes, etc.).

Criteria of marriage in silk-screen printing and elimination of its causes.

The main parameters of the grid for screen printing.

1. Mesh fiber material.

Silk fiber. Now it is practically not used. the threads had a poor weave structure and low stability. But thanks to the first use of this material in the production of a stencil, the word silkscreen appeared.

Kapron. This material has high elasticity and low stability. It is used when printing on uneven surfaces and cylinders.

Polyamide monofilament. This material has high stability after the screen is stretched on the frame. Stability refers to the maintenance of a constant tension of the sieve during its operation. In 80% of all work performed, it finds application.

metallized fibre. It is used for printing on materials with high electrification. This material has high stability and good dissipation of static electricity.

Stainless steel. Metal meshes have very high stability and low stretch ratio. These properties are indispensable for printing high-precision boards and scales. High wear resistance of the material is used when printing on glass and ceramics. Also grids possess high removal of static electricity.

2. Types of mesh weaving.

Plain weave (PW). In this weave, the weft thread is woven through each warp thread. The basis is the threads located along the sieve roll.

Twill weave (TW). In this weave, the weft thread is intertwined through two warp threads.

Calendered sieve. To reduce the consumption of paints and reduce the paint layer (UV paints, gold-containing paints, etc.), the sieve is calendered. Calendering is the process of passing a mesh between two rolls, one of which is heated. Due to this, under the influence of temperature, the tops of the threads in the kink zone are flattened. This leads to a reduction in the thickness of the sieve H and ultimately to a reduction in paint consumption. The calendered sieve can be single sided or double sided. With single-sided calendering, ink consumption is reduced by up to 25%, and with double-sided calendering, up to 50%. The disadvantages of calendering are a decrease in the strength of the sieve and a decrease in the open surface area.

3. Stencil number.

The number (grid number) refers to the number of threads in 1 cm or 1 inch.

Mesh number 120 means that 120 threads are intertwined in 1 cm. The higher the grid number, the smaller cells it has. When printing rough images, where a high hiding power or thickness of the ink layer is required, lower sieve numbers should be used. The principle is as follows: the lower the grid number, the lower the resolution of the stencil and the thicker the paint layer, which means more paint consumption. The main criterion for choosing the grid number is the required thickness of the ink layer and the minimum thickness of the printed line (resolution). If the line thickness is close in size to the diameter of the thread, then such elements may simply not turn out already at the copying stage.

Screen dots during the manufacturing process can get on the threads and eventually fail, other screen dots, on the contrary, can get between the threads and simply be washed off during the development of the stencil with water. A thin line can be covered with a thread and have breaks in the form of a dotted line during printing, problems can also arise with sharp corners, in general it is almost impossible to push ink through a small hole, because. the contact area of ​​the ink with the emulsion is larger than with the printed material.

The thicker the paint layer is needed, the larger meshes should be used. At the same time, one should not forget that if there are thin elements in printed motifs, the use of large grids can lead to distortion or complete absence of these elements during printing (insufficient stencil resolution). In such cases, a compromise must be found between the thickness of the ink layer and the resolution of the stencil. In some cases, it is advisable to make two stencils for the same color, with different grid numbers. On one stencil with a low mesh number we will get high coverage, and on the other with a high mesh number we will get high resolution.

4. Series of stencil grids.

With the same mesh number, there may be a different thread diameter. There is a classification of meshes by series: S - extra light, T - light, TH - medium, H - heavy.

The difference between the series lies in the difference in thread diameters, the heavier the series, the larger the diameter of the thread. Heavy series have greater circulation resistance, but a less dense ink layer. This results in less opacity of prints.

5. Stencil color.

The mesh is available in two types: unpainted (white) and dyed (golden yellow, orange).

Colored grid is recommended for copying very thin lines and raster images. When the light flux hits the grid, most of it passes through it, very small part reflected, and a significant part is scattered. The scattered light flux contributes to the side illumination of thin parts, which can then be poorly washed. The dyed nets absorb the light falling on the threads and prevent the dispersion of the light flux, which ceases to illuminate the photographic emulsion, similarly to a red light that does not illuminate photographic paper. When using colored grids, it should be taken into account that the exposure time of the photographic emulsion increases, since the value of the useful light flux decreases due to the neutralization of its scattered part.

Ink composition for screen printing.

1. Coloring substances. Coloring agents are pigments or dyes. Dyes are soluble in the dye medium (solvent). During the dyeing process, they penetrate into the material and form a more or less strong bond with the fibers. The pigments are insoluble. In the paint, they are in the binder (linseed oil, nitrocellulose, etc.) and the properties of the paint depend more on the binder than on the pigment. The bond with the material to be painted is provided by a binder. Dyes are usually organic matter. Pigments are mostly fine dispersions of minerals, although they can be either organic or inorganic. The introduction of pigments into paints and varnishes is the main method for regulating the decorative properties of coatings - color and opacity (hiding power). A pigment imparts opacity to a pigmented material if its refractive index is higher than that of the binder. How more difference in the refractive indices of the pigment and binder, the greater the hiding power of such a pigmented material. In addition, the shape of the pigment particles is important, for example, the lamellar shape of the pigment particles gives greater hiding power than needle or spherical.

2. Binder. The task of the binder is to stick the colorant to the surface of the printed product. Depending on the properties of the binder: adhesion of the ink to the printed material, drying methods, light fastness, ink layer height, gloss, abrasion resistance. The binder is usually based on a resin with a solvent, which is responsible for the consistency of the paint until it dries.

3. Additives. To improve the properties of the paint, there are various additives. The main types are listed below. Manufacturers may have other specialized additives.

Solvents - reduce the viscosity of the paint.

Retarders - reduce the viscosity of the paint and the speed of its drying.

Flow improvers - improve the flow of ink on the print, reduce the formation of small bubbles.

Thickeners - make the paint more viscous and thick.

Antistatic - improve the electrical conductivity of the paint, reduce the accumulation of static discharge, reduce static spatter.

Hardeners and catalysts - improve paint adhesion to difficult materials.

Matte additive - makes the paint more matte.

Pigments are coloring additives that increase the light intensity (saturation) of a color. Improper use of additives can impair the properties of the paint. Therefore, always strictly follow the recommendations of the paint manufacturer.

Basic paint parameters.

1. binder type. Printing, operational and adhesive properties of the ink depend on the type of binder.

2. Drying method (natural drying,. The speed of drying of the ink and its adhesion to the printed material depends on the drying method.

3. Hiding power (Transparent, translucent, semi-opaque, opaque, super opaque). The degree of hiding power shows how tightly the ink layer can hide the dark color of the printed material. If you print with transparent ink on black, the color of the ink will not be visible. If the paint is semi-opaque, then the color of the paint will be dirty due to the color of the substrate being translucent. Super opaque paints are able to cover the black color as tightly as possible.

4. Paint height (low, medium, high). The height of the ink indicates how thick the ink layer will remain after it has completely dried (Relief of the print).

5. Gloss level (paint super matte, matte, velvety matte, glossy, super glossy). Paint gloss refers to how much a paint layer can reflect or scatter light.

Variety of stencil inks.

There are four main types of inks used in screen printing: solvent, UV, and water-based. They differ in binding and drying method. Also, each type of paint has a large number of different series. Between themselves, the series differ in adhesive properties to various materials, elasticity, gloss, hiding power, thixotropy, etc.

IR - Infrared drying.

K - Convection drying.

UV - Ultraviolet drying.

* – Drying temperature depends on the paint series.

** - Used in two component series.

Chapter 4

A unifying and final chapter on the prepress process.
It describes how the image obtained in Chapter 2 is transferred to the stencil from Chapter 3 and the result is a printing matrix (or TPF - screen printing plate).

It all starts with cleansing...

So, we made a stencil. Now, before proceeding with the manufacture of the matrix, it is necessary to prepare or clean the grid. Be sure to remove oil, dust, dirt, ink and solvent residues before applying the emulsion layer (screen printing compounds) to ensure good adhesion.

To clean the mesh, use special formulations. It is not recommended to use household detergents due to the content of fragrances, hand softeners and bleaches, which can damage the mesh structure. Simply apply the cleaning compound to both sides of the stencil and wash with a sponge, after which thoroughly rinse with warm or cold water. Do not touch the mesh surface after the cleaning procedure is completed! Leave the stencil to dry.

If you are working with monofilament meshes, then sometimes an additional procedure may be required to give the fibers some roughness. For this, special compounds and coarse brushes are used. However, it should be noted that if a direct emulsion is used, and not capillary films, then this procedure is not necessary.

Photographic systems

Behind such a serious name are hidden photosensitive liquids(emulsions) or films, which are applied or adhered to a screen for exposure to ultraviolet light from film positives. Areas where the emulsion has been exposed to UV light become water-resistant, while those that were covered by the image on the positive remain water-soluble and wash off with water. Thus, the stencil turns into a printed matrix with an image. During the printing process, it is through these open areas of the mesh that the ink penetrates the product, forming an imprint.

Direct photographic emulsions are essentially glue-like light-sensitive liquids that are directly applied to a cleaned and well-dried stencil using a special device called a squeegee cuvette (figure on the right, details below)

Direct emulsions can be conditionally divided into three types: diazo sensitive (or just diazo), diazo-sensitive photopolymer emulsions of dual curing And one-component photopolymer emulsions. Actually, the first type is already considered obsolete. Dual-cure emulsions contain less water than older diazos and don't crack as much when dry. This provides sharper edges of the applied layer and speeds up the process of its manufacture. This type of emulsion is quite stable and can be used with water-based paints. Dual-curing emulsions are supplied in a two-component form - one part is the actual adhesive base, the second is a light-sensitive component that is added to the base before use. In one-component photopolymer emulsions, the base is already mixed with a photosensitive component, which facilitates the workflow. Moreover, they have an almost unlimited shelf life.

In addition to the above, photographic emulsions are characterized by viscosity, which is selected depending on the grid number, and the content of solid particles, which is important when reproducing small dots of the image.

Remember that for large runs (more than 500 pieces), water-based paints will require special waterproof emulsion. The matrix made with such an emulsion cannot be reused, because it is not possible to wash off the applied layer after the end of work.

How to work with two-component emulsions

Pour warm water into a small jar with a photosensitive component, dissolve it and the resulting mixture, after mixing, pour it into a jar with a base. Mix thoroughly and leave for several hours to release air bubbles.

Photo emulsions are relatively photosensitive, so we work either in subdued light (light bulb no more than 50 W), or in a room with tightly curtained windows. Since emulsions are very heat sensitive, they should be stored at a temperature not exceeding 35 °. The shelf life of the mixed emulsion is no more than two to three months.

The emulsion can be applied to the stencil even with a printing squeegee, but try to find an opportunity to purchase a special tool called a squeegee pan (see above). They come in different lengths. You should choose its size slightly smaller than the inner size of the stencil (frame). Then the squeegee-ditch will not touch the walls of the frame during the application of the emulsion, which will provide a tighter fit and, consequently, the application of a more uniform layer of emulsion.

The squeegee cuvette has rounded and sharp edges. Use a sharp edge for standard printing conditions, a rounded edge is needed for jobs that require a thick layer of ink on the product. Actually, the procedure for applying an emulsion to a stencil is one of the simplest in the entire printing process.

We repeat and say that you do not have to work in absolute darkness. Make sure that there is no direct sunlight in the room, the windows are curtained and strong light does not penetrate from below the door. You can simply seal the windows with a film that is impervious to UV light.

It should be taken into account that a dried matrix (stencil with an emulsion layer) is more photosensitive than a wet one.

Fill the squeegee cuvette halfway with the emulsion. Place the stencil in a vertical position and, starting from the bottom of the outer (printed) side of the stencil, lean the edge of the cuvette against the grid and tilt it so that the emulsion touches the grid, and start slowly moving the cuvette up (figure on the right). Now turn the stencil over and do the same manipulation on the inside (squeegee side). One coat of emulsion on the outside and inside will suffice if you are working with a high solids dual cure emulsion.

Some printers recommend applying two or three layers of emulsion on the outside and two or three more on the inside. However, this will result in a thick layer of emulsion, which will lead to problems with underexposure and therefore loss of fine detail. But for coarse meshes (lower number) several re-applyings are necessary.

If it seemed to you that the applied emulsion layer was not even enough, this can be corrected by running a squeegee-cuvette (but so that the emulsion does not fall on the stencil) over the dried layer.

Pour the rest of the unused emulsion into a jar, and the cuvette itself immediately ( ! ) wash. If this is not done, then the emulsion will clog the edge in the same way as any glue would. Take care of the edge of the squeegee cuvette, any damage to it will lead to an uneven layer of the applied emulsion.

The stencil with the applied emulsion should be dried in a dark room under the blowing of a fan, preferably in a horizontal position, with the bottom side of the stencil down. The recommended temperature in the room where the stencils with the emulsion will dry (this may be a special drying cabinet) is 38-43 °. Monitor indoor humidity. If the humidity is high, the stencil will take longer to dry. The normal drying time of the emulsion on the stencil is 30-60 minutes.

To determine the moisture in the emulsion layer (whether it has dried enough) an inexpensive device called a contact moisture meter will help. This electronic device accurately measures how much moisture is left on the surface of the emulsion.

The dried stencil can be stored for at least two to three months before use. This will allow you to prepare it in advance in your free time for customers. Like the emulsion, do not store the stencil at high temperatures, store it in a special light-tight box.

Straight capillary films

The second way to manufacture a matrix is ​​with the help of direct capillary films. This is a layer of photosensitive emulsion deposited on a base (transparent acetate film). They are sold in the form of sheets or in rolls, glued to the stencil with water, dried and illuminated in the same way as a direct emulsion. They are simpler and easier to use. they do not require mixing of any components, and the accuracy of the process is higher. True, capillary films are not very suitable for working on fine grids. The name "capillary" is due to the fact that the emulsion from the film base passes to the grid under the action of capillary forces.

It is very important to carefully observe the technique of applying to the stencil, because if the film is not properly glued, the film may simply fall off the grid. A significant advantage of capillary films is the very clear boundaries of the matrix (figure on the right). They help to avoid cracks during drying and are glued only to the bottom of the stencil. This matrix production system is ideal where a particular clarity of the pattern is required, as a rule, for non-textile types of printing - decals, posters, stickers, etc.

Since the capillary films are applied to a wet stencil, the process is accelerated, since the step of drying the washed stencil is not required, as is the case with direct emulsions. Thus, if it takes you an hour or two to make a stencil with a direct emulsion, then for a film stencil it will take you half an hour at most.

Straight films are produced in various thicknesses - from 15 to 84 microns (for three-dimensional paints up to 500-700 microns). For T-shirts, choose a film thickness of 35 microns, for transfer printing - 70-84 microns.

The exposure time of films of the same thickness is always constant and does not depend on the number and color of the grid.

Basic rules for working with capillary films

One could simply write "accurately follow the manufacturer's instructions", since capillary films are accompanied by fairly detailed descriptions. But still, let's dwell on the key points that allow us to make a high-quality matrix.

1. The stencil should be thoroughly cleaned and, most importantly, degreased. It is desirable to coarsen the grid to improve contact. This is done with special roughening agents with an abrasive (eg silicone carbide 500). The cleaned wet stencil can be further treated with special wetting compounds, since the better it holds water during gluing, the better the result will be.
2. As with direct emulsion, work under subdued (special) lighting.
3. The film is applied to the underside of the stencil, followed by a quick pass of the squeegee along the outer and inner sides of the stencil to push through water and improve adhesion.
4. Keep a spray bottle of water handy at all times. If you find poorly bonded areas, spray them with water immediately.
5. Dry the stencil in the dark under a fan. Drying will take 20-30 minutes. After drying, remove the acetate film base.
6. If you are accustomed to working with unstained direct emulsion, the exposure time for film should be doubled.
7. Wash the stencil from the underside after exposure. To knock out an unexposed emulsion, a slightly higher water pressure is required. If properly exposed, the film will adhere well to the stencil. If it peels off, then either the stencil is underexposed, or the mesh is poorly degreased.
8. For nets 90 and above, coarsening and degreasing are very important! On them, the film keeps worse than on large ones, so when washing off, reduce the water pressure.
9. To produce very strong matrices, film and direct emulsion can be combined. In this case, a dry stencil is placed on the film, an emulsion is poured on top and smeared with a squeegee. In this technology, the emulsion plays the role of water in gluing the film.

Printed stencils can be stored for weeks in a light-tight box. They are able to withstand print runs up to 30,000 prints.

exposition

To begin with, we recall that the emulsions we use are particularly sensitive to ultraviolet light. This implies the requirement for a light source for exposing stencils - it must give the required amount of UV rays.

For this purpose, you can use any source of UV radiation, including sunlight, but a high-quality matrix can only be obtained using professional equipment.

Professional exposure devices (starting at $2,500) use halogen, metal halide, or fluorescent lamps. For the choice of such devices - see the chapter " All about professional equipment".

In the picture on the right you will find how to make a simple stencil exposure device. To do this, you will need: a sheet of foam (5 or 7 cm thick and a size equal to the internal size of the frame), black cloth, a piece of glass (of the same size as a foam sheet). Note that the film positive must lie "backwards" as you are looking at it from below. Make sure the sides of the positive and the frame are parallel. Do not forget to secure the positive with tape so that it does not accidentally change its location when exposed. In this case, the exposure time will have to be selected by trial and error, since it depends on the distance from the light source and its power. When using a point light source, the distance from it to the stencil should be about 50 cm.

Keep in mind that when using daylight fluorescent lamps, you will not be able to get fine halftone dots (due to the diffusion of light rays).

When flashing on exposure devices, you put a film positive on the glass, then a stencil on it and on top of a dark cloth under the weight, to ensure good contact. In this case, the positive lies "correctly", i.e. exactly the way we look at it, and not vice versa. In professional exposure devices, the role of a dark fabric under the load is performed by a rubber vacuum blanket and there is a powerful point light source.

We deliberately do not give the exposure time, as it depends on the grid number, the exposure device and the emulsion used. Ask emulsion sellers for exposure scales for different grids. Let's just say that for colored grids, the exposure time increases by 30%, and if the positive is made on tracing paper, then by 30-50%.

The exact exposure time can only be determined empirically. However, the correct time obtained does not change until the light source or emulsion is changed. Particular precision is needed when very fine details are required. If you underexpose the stencil, then the emulsion will not harden and wash off, and if you overexpose, then the light penetrates through the positive and the details simply disappear.

In solving this problem, the "exposure counter" (figure on the right) will be useful. Exposing the stencil from this film only once, you see the result of five different exposure times at once.

You remember that for capillary films, time is constant and does not depend on the grid number. For direct emulsions, a grid with a smaller number shines less than a grid with a large number (a layer of applied emulsion of different thicknesses). In some cases it is possible to re-exposure, i.e. after exposure, washing and drying, we expose the matrix again.

Wash after exposure

After exposure, we place the stencil in the washing chamber and wash off the unexposed emulsion. We are still working in subdued lighting, since the unexposed photo-emulsion remains light-sensitive. We begin to wash off from the inside of the stencil with water of not too strong pressure. After a few minutes, you will see the emulsion begin to wash off. A special light source installed in the washing chamber, behind the stencil, will be very useful - you can see the results of your work. In places where the emulsion is not washed off, but should, slightly “help” it with your finger or increase the water pressure. After rinsing, absorb moisture from the matrix with a towel, and then dry under a fan or in a drying cabinet.

After drying, carefully look through the resulting matrix to the light. You may see unwanted "holes" in the area outside the drawing. Fix this by sealing them on the underside of the stencil with special blocking compounds, and for small runs (up to 100 prints) you can just use tape.

Retouch

We need to close the part of the mesh that is not covered by the emulsion layer, i.e. around the frame. Again, we use a blocking composition, smearing it with a spatula along the inner borders of the frame. You can use special restrictive strips for frames. They are also superimposed along the inside of the frame and fixed with tape.

The last step: preparing the matrix for printing

After the blocking composition has dried, glue the frame with special adhesive tape. You can use regular tape, but it's harder to remove after work.

Cleaning the matrix after printing

As a rule, the same stencil is used repeatedly. To prepare it for the manufacture of the next matrix, we do the following:

1. first, carefully wash off all the paint and remove the adhesive tape;
2. if you used a water-soluble blocking composition for retouching - wash it off with water, if not, then you will need a suitable solvent;
3. then proceed directly to the removal of the old emulsion layer. To do this, you can use various chemicals, including ordinary bleach, but better - special cleaners for matrices. Such a cleaner is applied to both sides of the matrix and after 1-2 minutes it is washed off from the hose with water under high pressure; Do not let the cleaner dry out - it will completely clog the mesh cells!
4. you may have to repeat the procedure from point 3 several times.

If you worked with a water-insoluble emulsion, then after printing it cannot be removed at all.

1. 
   Production of a screen printing form (TPF).

C) The printed grid is selected. The mesh should be chosen in the same way based on the image. Large images and plates should be printed on grids with a small number (for example, from 39 to 77). Thinner lines are printed on grids with numbers from 90 to 120. Raster images are usually printed on grids starting from 140. The first digit, in the grid number, indicates the number of threads per cm. The ink used in printing also affects the choice of grid. (For example, raster work, with plastisol inks, on textiles is printed using grids with a much lower number than when printing with solvent inks on paper.) It must be remembered that the choice of grid is always a compromise between the fact that a grid with a small number passes more ink ( the image is more saturated, and grid cells are less likely to clog), but at the same time it allows you to reproduce a coarser image and the fact that a grid with a large number reproduces thinner images, but at the same time the amount of ink passing through the grid decreases and there is a risk of "clogging" cells in the grid.

Screen mesh VS-Monoprint (Germany)

VS- MonoprinthighTenacity (HT) – This is a polyester screen mesh from the German concern Clear Edge-Germany GmbH for high-precision printing. Mesh series HT - High Tension Low Tlongation Polyester fabrics are made from high tenacity polyester yarn with low elongation. The creation of this series of meshes was the result of the cooperation of technological features, the electronics industry and the requirements of silkscreen production. The result is a mesh with the following characteristics:

Low elongation

Ability to withstand high tensile force

Increased characteristic "fatigue resistance"

In practice, these properties lead to the following advantages:

High tensile strength allows you to set the minimum "Off-contact" (technological gap between the plane of the printed product and the plane of the stencil)

Which in turn leads to the need for less pressure of the squeegee blade on the mesh, as a result of which the service life of the stencil increases.

Grid VS-Monoprint High Tenacity (HT) - intended for:

Printing both solids and halftone bitmaps

Uses with diazopolymer emulsions and capillary films

Printing with UV-curable, solvent, plastisol, water-based and abrasive decal inks and pastes.

Use on stencils of both small and large formats

All the company's products are DIN EN ISO 9001:2000 certified. HT - High Tension Low Tlongation Polyester fabrics PW - plain weave TW - twill weave

PES - polyester monofilament mesh, PW - single weave, TW - double weave, W - white mesh, Y - yellow mesh, * - maximum recommended tension for small and medium formats.

In accordance with the company's policy of continuous improvement of product quality control, we reserve the right to make changes to the technical parameters.

The use of colored meshes provides the following advantages:

When the emulsion layer is illuminated, the dyed thread does not scatter, which makes it possible to obtain a higher quality stencil

Allows you to get stencils more resistant to abrasive and chemical attack

Allows the use of stencils with a higher degree of tension

A = Open area in %

B = Open cell size in microns

T-shirts: from to

Glitter powders PES 10/270 PW PES 25/120 PW

Flock PES 16/215 PW PES 45/80 PW

Sublimation PES 77/48 PW Y PES 120/35 PW Y

Plastisol PES 55/60 PW Y PES 120/35 PW Y

Color pigments PES 61/60 PW Y PES 100/40 PW Y

Textile, flat print

Heavy fabrics PES 16/215 PW PES 49/80 PW

Other PES 42/80 PW PES 80/55 PW

Lightweight, light-colored fabrics PES 80/55 PW Y PES 100/40 PW Y

Ceramics

Glaze, rough PES 5/500 PW PES 21/150 PW

Glaze, gloss PES 21/150 PW PES 61/60 PW

Direct Print PES 42/80 PW PES 90/48 PW

Decal PES 77/48 PW PES 180/25 PW

Glass

Auto glass, etc. PES 55/70 PW PES 120/35 PW Y

Decorative products PES 77/48 PW PES 140/35 PW Y

Plastic

Solvent paints PES 100/40 PW Y PES 165/30 PW Y

Paper (graphic printing)

Solvent paints PES 80/55 PW Y PES 140/35 PW Y

UV inks PES 140/35 PW Y PES 180/27 PW Y

C ) Mesh tension on the printing frame . A wide variety of devices are used to stretch the mesh onto the printed frames. (Pneumatic tensioners, mechanical tensioners, self-tensioning frames, etc.). Consider the simplest and most commonly used tensioner - the self-tensioning frame.

R
ama self-tensioning Newman Roller Frame for tensioning nets on smaller frames. Format 510x720 mm (external 570x790 mm.) Made in the USA

The principle of operation of the frame is quite simple. Each of the sides (or three sides) has the ability to rotate and at the same time be fixed with end bolts in a given position. Each side has a recessed chute with a plastic strip inserted into the grooves of the chute. The tensioning process is as follows: The mesh is placed on top of the self-tensioning frame, so that on each side the mesh is at least 5-10 cm longer than the frame. grooves of the gutter, over the mesh, then, the same procedure is carried out with the opposite side, and then with the sides. It is important in the corners of the grid to make before the weakening of the grid. After that, the rotation of one side of the frame begins, after which the side is fixed with an end bolt, then the opposite side rotates and is also fixed. The same thing happens with the sides. Thus, gradually your mesh acquires a significant tension. (The degree of mesh tension is checked with a Newtonometer (required for raster full-color works) or visually for works that do not require such accuracy). Further, the tension frame itself can be used as TPF or cheaper printed frames can be used. In the second case, the aluminum frame is placed under the mesh stretched over the self-tensioning frame and coated with special glue. (in some cases, it is required to degrease and roughen the smooth surface of the aluminum frame first for better adhesion of the adhesive to the surface.

Adhesive for gluing the mesh to the frame KIWOBOND 1000 HMT

KIWOBOND 1000 HMT is a fast-drying two-component adhesive with exceptional adhesive properties and increased resistance to aggressive media. Suitable for all types of frames: wood, aluminum or steel. After polymerization, it practically does not react with solvents. Thanks to its fast drying time, KIWOBOND 1000 HMT allows screen meshes to be bonded under high tension and ensures that there is no loss of tension after the frame has been removed from the tensioner. The adhesive layer does not become brittle after polymerization and does not cut the mesh at the edges.

Application

• 
  before tensioning the mesh, completely remove dirt, dust, old glue, paint and mesh from the frame. The gluing area must be free of grease and other substances that adversely affect the quality of the gluing.
• 
  degrease the frame surface with PREGAN (-NT-) PASTE, PREGAN A9 EXTRA or PREGAN NT9. For best results prime the frame surface with KIWODUR 1000 HMT hardener.
• 
  Immediately before gluing, mix 5 parts of KIWOBOND 1000 HMT (base) with 1 part of KIWODUR 1000 HMT (hardener), i.e. the additive is 20% hardener. Mix well both components and use within 45-70 minutes.
• 
  Thoroughly coat with glue all the places of gluing with a stiff brush. The polymerization time of the adhesive depends on many parameters: mesh number, coating thickness, temperature, air circulation in the room.
• 
  Average polymerization time of the adhesive (at 20 С):

Although the adhesive achieves good resistance to water and solvents within an hour, full cure and resistance is achieved within 24 hours.,

D ) Mesh preparation for application of photosensitive emulsion.

Before a photographic emulsion is applied to the stretched mesh, the mesh must be degreased. (For better contact of the emulsion with the mesh thread)

Mesh preparation degreaser PREGAN A9 EXTRA

Description. Ready-to-use liquid degreaser for the preparation and degreasing of meshes in the manufacture of screen printing plates using direct photographic emulsions. It is applied to all types of grids. Its use prevents the appearance of dot punches in the emulsion, and its peeling during the printing process. The viscosity of the degreaser provides significant economy of use and exceptional performance on any mesh. The degreaser is bioregenerated. Green color.

Characteristics:

• 
  biorecoverable viscous liquid;
• 
  high efficiency;
• 
  promotes uniform application of the emulsion;
• 
  forms a stable aqueous film suitable for transferring capillary films;
• 
  can be used in normal working areas;
• 
  

Application. When degreasing any new and used nets:

• 
  squeeze a few drops of the degreaser onto the mesh, rub the degreaser well on both sides of the mesh with a soft sponge or brush until a uniform coating is obtained and leave for 1 - 2 minutes;
• 
  Rinse thoroughly with water until the formation of foam stops. Grease and dirt, emulsified with water and a degreaser, are washed off the mesh very quickly;
• 
  dry the mesh
• 
  mesh is ready to be emulsified. The capillary film is applied within 1 minute after the mesh has been treated with a degreaser.

Storage. 12 months in tightly closed original packaging. Store at a temperature of 20 - 25 С. The freezing point is about 0 С. After defrosting it can be used without any problems.

After that, the emulsion can be applied to the grid. This requires the use of a squeegee cuvette, which is a trough with a smooth edge. A sensitized emulsion is poured inside the chute, after which the emulsion is applied to a vertically held printing frame. The application should be uniform and on both sides of the mesh (most often the mesh is watered according to the 2 + 1 scheme). It is important to remember that the applied emulsion on the grid should be at least 3 cm larger than your image on each side.

Photo emulsion AZOCOL Z1

Universal Diazo UV Polymer Emulsion for Straight Screens

Photo emulsion AZOCOL Z1 It is used for the preparation of high-quality stencil forms with good resistance to any inks, both solvent-based and water-based. Universal emulsion, recommended for use in almost all areas of screen printing. The stability of the emulsion layer depends to a large extent on the humidity of the air.

Sensitization

The operations of sensitization, application, drying, exposure and rinsing must be carried out under yellow, safe, non-active light (ordinary incandescent bulb). Applied sensitizer - Diazo No. 6.

Sensitization order:

• 
  pour water with a temperature of 20-25 С into the bottle with the sensing agent into 3/4 of the bottle - according to the upper mark;
• 
  mix well until the powder is completely dissolved;
• 
  pour the sensitizer solution into the emulsion and mix thoroughly;
• 
  refill the bottle with the sensing agent with water by 1/4 of the bottle - at the bottom mark;
• 
  shake until complete dissolution of the residues of the sensing agent, pour into the emulsion and mix;
• 
  allow the emulsion to stand for several hours until the bubbles completely disappear.

Mesh preparation

For optimum results, the screen must be cleaned and degreased prior to emulsion application. For this, products of the family PREGAN, eg. PREGAN A9 EXTRA, PREGAN NT9 or PREGAN (-NT-) PASTE (see separate technical sheet).

Degreasing procedure:

• 
  apply a small amount of degreaser to the mesh and rub it evenly with a soft brush or foam sponge on both sides;
• 
  wait 3-4 minutes for dirt and greasy areas to emulsify and become water-soluble;
• 
  rinse the mesh with water until the foam disappears;
• 
  dry the mesh with warm air at a temperature of 35-40 С (preferably in a drying cabinet).

Application

The application of the emulsion (watering) is done manually with a squeegee - a cuvette or with the help of automatic devices such as KIWOMAT. The working length of the squeegee - cuvette is selected in accordance with the required dimensions of the frame and / or printing.

The procedure for applying emulsion:

• 
  pour the required amount of sensitized emulsion into a squeegee - cuvette;
• 
  put the frame in a vertical position;
• 
  Carefully apply layers of photo emulsion on the printed side of the grid. It is necessary that the emulsion evenly fills all the grid cells;
• 
  apply the emulsion to the squeegee side of the screen. The number of applied layers depends on the nature of the reproduced image and the type of grid.

Drying

side down.

E ) Exposure (flare) of the emulsion. In order to obtain TPF for illumination, it is necessary to obtain original layouts, which will be an image broken down by colors. For color separation, as a rule, programs like CorelDRAW, etc. are used. To output layouts, either phototypesetters are used, or, if the image allows, a black-and-white laser printer and Kimoto-type output film. Illumination takes place in special exposure chambers, or, if the image allows, using metal halide spotlights. The illumination process usually looks like this: the original layout is placed on the glass (with toner or emulsion to TPF), the frame with the applied emulsion is placed on top. Next, the frame is pressed against the original layout (the better the clamp, the better the stencil accuracy will be). Illumination occurs from below through the glass from a distance of about 0.6 - 1 m.

The stencil is formed under the influence of UV radiation by curing the non-printing areas of the emulsion. Exposure to produce blue actinic light with a wavelength in the range of 350 - 420 nm. A metal halide spotlight provides the best results.

After exposure, the frame is washed with water and the elements covered on the original layout are not cured on the grid. When washing, they are removed leaving the grid cells open. It turns out a screen printing form (TPF)

Due to the variables that define a particular exposure time, it is not possible to give a single exposure time. Optimum results can only be achieved by trial exposure (step exposure). To achieve maximum shape stability, it is necessary to choose the maximum exposure time. At the same time, it is necessary to take into account the quality of the elaboration of small details of the original layout. This is especially important when working with water-based paints, because. the necessary resistance of the stencil in this case is achieved precisely by increasing the exposure time.

Basic values:

Light source: 5 kW metal halide spotlight at a distance of 1 meter. The emulsion is applied twice on the printed side and two (2+2) or four (2+4) times on the squeegee side.

retouching

In the case of printing with water-based inks, retouching is done with water-resistant retouching KIWOFILLER WR/01. It is removed using emulsion peelers of the family PREGASOL and hydrogun ( detailed description- see separate technical sheet).

Peeling

In general, molds made using AZOCOL Z1 emulsion are easily removed with products PREGASOL, e.g. PREGASOL EP3, TABS, F, P.

How to peel emulsion:

• 
  carefully remove all paint from the stencil with PREGAN 244 E thinner;
• 
  apply an aqueous solution of a peeling agent to the emulsion layer;
• 
  avoiding drying, hold for 5-8 minutes;
• 
  rinse with a stream of water under strong pressure (from a hydrogun);
• 
  to remove possible residues of emulsion and paint in the grid nodes, as well as shadow images, the subsequent use of cleaners is necessary PREGAN: PREGAN (-NT-) PASTE + PREGAN C 44 A, PREGAN ANTI GHOST EXTRA, PREGAN MEGACLEAN LIQUID (see respective technical sheets).

Attention! Do not freeze emulsion! She will lose her properties!

2) Print.

A ) Machine. The resulting TPP is installed in the printing press. Machines can be manual or semi-automatic. Can be with or without vacuum clamp. They can be micro-registered or not. Nevertheless, in any machine, the frame is fixed in holders. Then the setup takes place. The printed product is located on the printing table (as a rule, a reference corner is glued on the table with a self-adhesive film, into which the product will fall every time). With the help of micro registers, the TPF is positioned relative to the product so that the printing takes place in the right place. It also creates a gap between the TPF and the product necessary for printing (usually the gap is 1.5 mm, but this depends on the product and on the image and on the paints used). After adjustment, all registers are fixed with special clamps. Further in the printing process, it is important that the machine keeps all the settings achieved. The presence or absence of a vacuum clamp affects performance.

Our recommended machines:

Professional manual machines "PROFI - Vacuum" SH-7080 and SX-6070 are high-class machines that allow you to print on flat surfaces.

Equipped with a table, made of stainless steel, with holes with a diameter of 1.5 mm, with a powerful vacuum clamp, with double vacuum break adjustment. Table size 700x800 mm. Adjustable print frame counterweight. Micrometric registers of the printing table (step - 0.1 mm) provide any alignment accuracy in multi-color and full-color printing and allow you to perform large amounts of work.

Machine "Universal" WSC-500H. Printing unit with micrometric registers of the printing form (print format up to A2). Without a table.

B) Printing doctor blade and doctor blade holder.

In order for the ink to be forced through the mesh cells onto the printed product during the printing process, a special doctor blade is used. The canvas comes in various shapes and different stiffness. In manual printing presses, a rectangular profile sheet P0 9X50mm is used. Cloths have different rigidity. The most common canvases are 65Sh soft, 75Sh medium and 85Sh hard (usually used for fine line printing and raster work). When manually printing, the doctor blade must be fixed in doctor blade holders that will allow the printer to freely hold the canvas during printing.

C) Paints and cleaners.

The selection of paint is carried out primarily on the basis of what kind of material will be printed (paper, PVC, ABS, polyethylene, polypropylene, glass, metal, ceramics, wood, etc.) Below are the most commonly used paints

Technological instruction for paint RUCO (Germany) Series 10 KK

Application area: Universal two-component screen printing ink for printing on glass, acrylic, thermoset plastics, lacquered surfaces, metal, polyamide, polycarbonate, pre-finishedPP/ PE(polyolefins - polypropylene, polyethylene), polyurethane and rigid polyvinyl chloride.

Peculiarities: Paint series 10 KK is glossy, chemical drying. At the same time, it has a high degree of fixing, without losing elasticity. This paint does not contain toxic elements in its composition. It fully complies with the European safety standards (Europa-Norm EN 71, teil 3) of 1994. The paint series 10 KK shows high mechanical and chemical resistance.

Colors: Pantone, HKS, RAL, NCS

Standard base colors:

color fastness:

Light yellow G1 10 KK 2242 Light yellow B1 10 KK 2291

Yellow G2 10 KK 2292 Yellow B2 10 KK 2243

Orange G3 10 KK 3737 Orange B3 10 KK 3851

Light red G4 10 KK 3738 Light red B4 10 KK 3852

Red G5 10 KK 3739 Red B5 10 KK 3853

Pink G6 10 KK 3740 Pink B6 10 KK 3854

Violet G7 10 KK 5752 Violet B7 10 KK 5851

Blue G8 10 KK 5720 Blue B8 10 KK 5852

Green G91 10 KK 6702 Green B91 10 KK 6571

Brown G10 10 KK 8290 Brown B10 10 KK 8337

White G11 10 KK 1045 White B11 10 KK 1055

Black G12 10 KK 9025 Black B12 10 KK 9029

Transparent base 10 KK 0026 Transparent base 10 KK 0026

High opacity colors:

White high opacity 10 KK 1047

Black high opacity 10 KK 9026

Bitmap colors:

Yellow 10 KK 2187

Purple 10 KK 3561

Blue 10 KK 5629

Raster black 10 KK 9035

Varnish for selective varnishing 10 КК 011

Raster paste 10 KK 0018 (may be added to the paint no more than 10%)

Series 10 KK inks are produced ready for printing. If necessary, you can change the viscosity of the paint with a thinner.

Thinner, for glass 100-VR-1390 (added to paint 15-25%)

Please note that Thinner 100-VR-1390 can only be used in combination with Glass Hardener 100-VR-1294 (100-VR-1320).

Optionally, a very slow moderator 100-VR-1170 can be used.

Retarder, very slow 100-VR-1170 (added to paint max. 10-20%)

As a hardener, it is recommended to use the standard hardener 37 172. The paint life with this hardener is 12 hours (at a temperature in the workshop of 20 degrees). For printing on glass, it is recommended to use hardener 100-VR-1294 (100-VR-1320). The life of paint with this hardener is 12 hours (at a temperature in the workshop of 20 degrees). Drying time of paint 10 KK in combination with 100-VR-1294 (100-VR-1320) 25 minutes at a temperature of 180 degrees.

Complete drying of paint 10 KK with the addition of hardener 37172 occurs within 36 hours at a temperature of 20 degrees. After that, the colorful print has all the final properties. Also note that if the air temperature drops below 15°C during printing or drying. the chemical curing process is interrupted. Also, the process of chemical curing of the paint is interrupted if the air humidity rises by more than 65%.

Hardener, standard 37 172 (max. 20%)

Hardener, glass 100-VR-1294 (100-VR-1320) (max. 5%)

Printing instructions:

Preliminary processing

When working with inks of the 10 KK series, any types and numbers of grids, as well as any types of printing machines can be used (the maximum possible printing speed with 10 KK inks is 1,600 passes per hour).

Drying conditions

All colors of the 10 KK series are chemically cured due to the cross-linking of molecules. For multi-color printing, it is recommended to use intermediate IR drying or hot air blowing.

Cleaning:

Technological instruction for paint RUCO (Germany) Series 700 ST

Application area: Screen ink for printing on lacquered surfaces, metal, paper, cardboard, polyamide, polycarbonate, pre-treatedPP/ PE(polyolefins - polypropylene, polyethylene), polyurethane, rigid polyvinyl chloridePVCand as a two-component paint onPET/ PETG.

Peculiarities: The 700 ST series paint is glossy, physical dry (if as a single component) and physical dry when hardener is added. At the same time, it has a high degree of fixing, without losing elasticity. This paint does not contain toxic elements in its composition. It fully complies with the European safety standards (Europa-Norm EN 71, teil 3) of 1994. The 700 ST series paint shows high water resistance, mechanical resistance and chemical resistance to various alcohols, acids, oils, fats, and is also suitable for outdoor advertising because of the high lightfastness of paints and resistance to weather conditions.

Colors: The paint consists of 12 basic colors that can be mixed according to Pantone, HKS, RAL, NCS according to a proven recipe and a large selection of specialty colours.

Standard base colors: Base colors with high light and

color fastness:

Light yellow G1 700 ST 2102 Light yellow B1 700 ST 2138

Yellow G2 700 ST 2139 Yellow B2 700 ST 2139

Orange G3 700 ST 3296 Orange B3 700 ST 3413

Light red G4 700 ST 3414 Light red B4 700 ST 3414

Red G5 700 ST 30107 Red B5 700 ST 3415

Pink G6 700 ST 3300 Pink B6 700 ST 3416

Purple G7 700 ST 5284 Purple B7 700 ST 5418

Blue G8 700 ST 5285 Blue B8 700 ST 5419

Green G91 700 ST 6761 Green B91 700 ST 6761

Brown G10 700 ST 8086 Brown B10 700 ST 8108

White G11 700 ST 1020 White B11 700 ST 1022

Black G12 700 ST 9004 Black B12 700 ST 9005

Transparent base 700 ST 0003 Transparent base 700 ST 0003

High opacity colors:

High Opacity White 700 ST 1014

Black high opacity 700 ST 9005

Bitmap colors:

For raster printing in accordance with DIN 16538, 4 raster colors according to the Euroscale are offered.

Yellow 700 ST 2109

Purple 700 ST 3328

Blue 700 ST 5312

Bitmap black 700 ST 9007

Additives and auxiliary chemistry:

Varnish for selective varnishing 700 ST 0003

Screen paste 700 ST 0007 (can be added to the paint no more than 10%)

With the help of raster paste, you can improve the reproduction quality of fine elements in raster printing.

The 700 ST series inks are produced ready to print. If necessary, you can change the viscosity of the paint with a thinner.

Thinner, very fast evaporation VS 35 353 (added to the paint 15-25%)

Thinner, standard VD 38 571 (added to paint 15-25%)

Thinner, special 35 696 (added to paint 15-25%)

With the retarder VZ 35 928 you can increase the drying time of the ink when printing. Also for this purpose, the retarder VZ 34 392 can be used (can be used in cases where it is necessary to further increase the drying time). When working in extreme climatic conditions (at temperatures above 28 degrees), it is recommended to use the retarder VZ 35 928 and as a thinner to change the viscosity.

Retarder, slow VZ 34 392 (added to the paint max. 5%)

Retarder, standard VZ 35 928 (added to paint 5-10%)

Please note that the use of a retarder increases the drying time of the impression. These retarders are only recommended for use in combination with Thinner 38 571.

A flow enhancer can be used to enhance the fluidity of the paint.

Flow enhancer VM 100 VR 133 (can be added to the paint no more than 0.5-1%)

As a hardener, it is recommended to use the standard hardener 37 172. The paint life with this hardener is 12 hours (at a temperature in the workshop of 20 degrees). If fast drying of the print is required, it is recommended to use the SE 5214 hardener. The pot life with this hardener is 8 hours (at a workshop temperature of 20 degrees).

Hardener, standard 37 172 (5 parts paint and 1 part hardener)

Hardener SE 5214 (5 parts paint and 1 part hardener)

Complete drying of paint 700 ST with the addition of hardeners occurs within 36 hours at a temperature of 20 degrees. After that, the colorful print has all the final properties. Also note that if the air temperature drops below 15°C during printing or drying. the chemical curing process is interrupted. Also, the process of chemical curing of the paint is interrupted if the air humidity rises by more than 65%.

When using a hardener, any subsequent overprinting is only possible within 36 hours.

Printing instructions:

Preliminary processing

A high degree of ink adhesion when printing on polyethylene and polypropylene can only be achieved if these materials are activated qualitatively. Activation can be either an open flame or a corona discharge. The surface tension should be at least 42 mN/m for polyethylene and 52 mN/m for polypropylene.

Printing form and equipment

When working with inks of the 700 ST series, any types and numbers of grids, as well as any types of printing machines, can be used (the maximum possible printing speed with 700 ST inks is 3,600 passes per hour).

Any doctor blade known on the market can be used as a doctor blade.

Drying conditions

All colors of the 700 ST series are physically cured by evaporation of the thinner, if using a hardener, chemically by crosslinking molecules. For multi-color printing, it is recommended to use intermediate IR drying or hot air blowing. Complete physical drying occurs within 1-2 minutes at a temperature of 70-80 degrees.

Cleaning:

The stencil, doctor blade and other parts can be cleaned with cleaner 32335. If cleaning is not done in an automatic machine, rubber gloves must be worn by personnel.

Universal cleaner UR 32335

Universal cleaner for automatic systems WR 100 VR 1240 C

Biological cleaner BR 100 VR 1272

After printing it is necessary to clean the TPF from paint residues. If this is not done, then the paint will dry on the mesh, after which the stencil will have to be thrown away. (this does not apply to plastisol paints and some others). To do this, form cleaners are used both after printing and during printing (not allowing paint to clog grid cells during operation).

PREGAN 235S.

Description. A unique, unparalleled tool for cleaning matrix cells during printing and for cleaning screen printing plates from ink after the printing process is completed. The matrix is ​​preserved (not blurred). Exceptional ease of use. An indispensable tool in terms of ease of use and efficiency, which allows you to clean the cells of the printed matrix clogged with ink that has dried up during the printing process. Used for ALL types of paints.

Application area.

1. When printing with drying inks, the cells of the matrix become clogged with dried ink. The smallest particles of an aerosol effectively physically and chemically influence the smallest volumes of the dried-up paint; the spray has no unpleasant odor; spent very sparingly; allows you to protect the health of the worker, excluding physical contact with the solvent. Printers around the world use the KIWO PREGAN 235 S very widely.

2. Removes the remnants of any ink from the matrix after the end of the printing process. The matrix is ​​saved and allows you to resume the printing process if necessary.

Application.

When printing.

The spray is applied in a circular motion from a distance of 20 - 30 centimeters on the printed or squeegee side of the matrix after the ink dries or before drying (if the printer feels that the matrix is ​​starting to clog). Thereafter:

1) the matrix is ​​​​slightly wiped with a rag

2) dried cells are opened with a very slight movement of the squeegee.

The cleaning process is complete. You can print again.

After print.

• 
  
• 
  apply the spray in a circular motion from a distance of 20 - 30 centimeters on the printed and squeegee side of the matrix. After that, wipe the matrix well with a soft sponge or swab on both sides of the grid;

Active Screen Cleaner

after printing

PREGAN 244 E

The most versatile tool to date.

It cleans matrices more effectively than any other means for both water-soluble paints and solvent-based paints. Particularly suitable for drying pigment inks, pressure-sensitive and flock adhesives, as well as for printing with various pastes and varnishes. It is more biologically harmless than any other similar cleaner. Virtually odorless. Color - colorless.

Characteristics:

• 
  liquid;
• 
  high cleaning efficiency;
• 
  low odor level;
• 
  liquid is chemically stable.

Application area. Removes the remnants of any ink from the matrix after the end of the printing process. The matrix is ​​saved and allows you to resume the printing process if necessary.

Application.

When cleaning the sensor:

• 
  after printing with a spatula (spoon), remove the remaining paint from the matrix;
• 
  wipe the matrix well with a soft sponge or swab moistened PREGAN 244 E on both sides of the grid;
• 
  for dried paints, leave the solution on the matrix for 10 - 15 minutes, then rinse with water and rinse the matrix with a strong stream of water;
• 
  dry the net.