Screen printing process technology and detailed operation (2)

Second, the seal film method plate

1. Sealing film paper formula and production

1 Formulation and production of Lacquered film paper

formula

Soft clear paint 100g

Premium Banana Water or Butyl Acetate 200-300g

Castor oil 4-6g

operating

Apply tracing paper or cellophane to a flat board or glass, mix rubber water and gasoline 1:1, apply a shading brush on the paper to make a barrier layer, wait until the paint is dry, and spray the gun about 20cm away from the paper. It is advisable to spray it seven or eight times. Thickness is controlled by oneself. General lak paper can be prepared for thick, medium and thin profits. Spray the first layer to dry before spraying the second layer, the third layer ... ... If the production volume is small, you can use shading brush.

Soft clear spray paint is a colorless transparent body. In the production of wax paper, the paint must be dyed, that is, a little blue or magenta, green paint is added in the paint, which is easy to distinguish between engravings, and the color should be light, not too Thick, otherwise it will affect the sight of the seal, the dye should be dissolved with alcohol.

Castor oil should be increased or decreased according to the spray paint performance, weather changes, dibutyl ester can replace castor oil, but not as good as castor oil.

2 gelatin paint film formula and production

formula

Special Gelatin 20g

Clear water 100-300g

Glycerine 3-7g

operating

The gelatin was placed in a container filled with fresh water and steamed and dissolved. Glycerin and a little blue dye were added. The mixture was stirred well with glass and filtered through a mesh of 100 mesh or more.

Paste the polyester film base on a very flat board or glass plate, use the shading brush to paint the vinyl chloride paste and cyclohexanone dissolver on the base of the film as a separating layer, dry the paint or shading Brush system can also (the method with the previous).

Allow it to dry naturally, place it in a dry and ventilated place for future use.

When preparing temperature 180°C, sodium sulphate 1g can be added

Formulation and production of modified nitrocellulose varnish paper

formula

A party

Nitrocellulose 10g

Butyl acetate 90g

Ethyl acetate 50g

Butanol 10g

Toluene 40g

Party B

Melamine formaldehyde resin 12g

Castor oil modified alkyd resin 20g

Party A and Party B are reconciled and fully mixed.

The method of operation is the same as the lacquer paper, and the plate can be engraved by heating at 120° C. for about 2 hours.

2. Sealing film paper

Put the painted ink on the underside of the paint sheet, and paste it with transparent tape. Use a carving knife to remove the paint film from the backing paper.

Multi-colored seals should be carefully examined and the sequence of multi-colored overlays should be clearly distinguished. In order to prevent walks, the scope of the first coloration at the time of carving is slightly larger than that of the original, and the range of the second color and the size of the manuscript are large. After the kiss. The first printing should be engraved to be wider, and the latter printing should be larger. In addition, when engraved on the contour line, the color of the line pressed by the contour line should be placed at 1/2 of the outer knot, and the contour line should be etched to be equal to the original.

3. Upper version of paint film

1Lak paint film paper

Put the carved version on flat glass paper, and place the stretched net frame on the top. Rub the right hand with a piece of banana water on the screen plate with a cotton wool towel. The left hand will take the dry cotton and press it to make the film of Wire mesh sticks.

After the plate is completely dry, remove the backing paper, and wipe the rubber traces on the back side of the plate with the rubber.

If there is a place on the plate, you can use banana water to make up for it. If there are knife marks and small strokes that are detached from the blade, you can use a brush to fix it.

2 gelatin paint paper

The rules are written on the manuscript, and many sets of color plates use this rule as the loading rules.

Put the carved version together with the original, placed on the appropriate position of the screen platen, according to the original rules of the rules of the binding rules of the paste with paste glue on the screen plate, and paste firmly, there are several sets Color uses a few silk screens to set uniform rules.

Put the manuscript together with the carved version on a well-defined platen, put down the screen frame, and use the iron to align the square edge of the carved gelatin plate on the silk screen to fix the iron plate on the screen. After removing the original sample.

Put some thick cardboard on the platen, lay down the screen frame to make the gelatin engraved paper pad flat, and then cover the polyester film on the screen to form a gap. Iron and squeezing the film several times to make the gelatin film iron On the screen.

Let it dry naturally after getting a good version, then remove the liner and use cyclohexanone to wipe off the vinyl traces on the back side of the layout and the spacer paper.

If there is a place where the plate is peeled off, it is filled with glacial acetic acid. If there are knife marks and small strokes that are detached from the blade, you can use a brush to make up the gelatin solution.

3 nitrocellulose varnish modified film paper version

The nitrocellulose varnish modified varnish paper has the same printing method as above.

4. Sealing film on paper film

Sealing net is close to the screen and the text outside the screen with a gel sticking up, so that it does not leak ink during printing, lacquer film net seal available nitro lacquer, gelatin solution can seal the gelatin film and nitrocellulose lacquer Modified paint film. After the sealed plate is dry, it can be printed.