Manual Screen Printing Technology (1)

The manual screen printing process is simple in operation and can meet the requirements of screen printing without expensive equipment. With less investment, good quality, and high efficiency, it also occupies considerable advantages in the screen printing industry. The manual screen printing is divided into three parts according to its process flow, as follows, for the reference of the beginners.

Screen printing plate

Screen printing plate in the operating technology has carved film and photosensitive printing plate division, depending on the printability of the substrate and choose a different plate-making method. For example, the screen printing of text lines and patterns can be selected from the lacquer-printed paper plate, and the screen printing with continuous adjustment of the level pattern can be selected from the screen-printing printing plates. Here is a description of its plate making method.

First, the lacquer film network printing plate

(1) Formulation and production of paint film 1. Formulation and production of lacquer film paper Formula Soft clear spray paint 100g Premium grade banana water or butyl acetate 200-300g Castor oil 4-6g Operation

Apply tracing paper or cellophane to flat wood or glass, mix rubber water and gasoline 1:1 uniformly, apply a brush on the paper as a barrier layer, wait until the paint is dry, spray the gun away from the paper About six or seven inches is appropriate; it can be sprayed seven or eight times. Thickness is controlled by oneself, generally the wax paper can be prepared thick, medium, thin three kinds. Spray the first layer to be slightly dry before spraying the second layer, the third layer... If the amount of production is small, shading can also be used.

The soft clear spray paint is a colorless transparent body. In the production of the wax paper, the paint must be dyed, that is, a little blue or magenta, green pigment is added in the spray paint, which is easy to distinguish between engravings, and the color should be light and not suitable. Too strong, 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 and 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 Glycerin 3-7g Operation

The gelatin was placed in a clear water filled with a container and steamed and dissolved. Then, glycerin and a little magenta dye were added, and the mixture was thoroughly stirred with a glass rod and filtered with a mesh of 100 mesh or more.

Laminate the polyester film base on a very flat board or glass plate, brush the vinyl chloride paste and cyclohexanone solvent on the paper as a barrier layer with a shading brush, dry it and spray or shave Brush can also (the method with the previous).

Allow it to dry naturally, place it in a dry place and store it for use.
When the temperature exceeds 180°C during preparation, 1 g of sodium sulfate can be added.
3. Formulation of nitrocellulose varnish modified paint paper and preparation of formula A side nitrocellulose 10 grams butyl acetate 90 grams ethyl acetate 50 grams butanol 10 grams toluene 40 grams B side melamine formaldehyde resin 12 grams castor oil modified alcohol Twenty grams of acid resin is used to reconcile the A-side and the B-side, and stir well.

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

(II) Cutting 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.

With multiple sets of color seals, it is necessary to carefully examine the drawings and distinguish the order in which the colors overlap. In order to prevent walking, the scope of the first coloring 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 original are so large that it fits exactly after printing. The first printing should be engraved and the latter must be kept large. In addition, when engraved on the contour line, the color of the line pressed by the contour line should be placed on the outer half of the line, and the outline line should be engraved to be equal to the original.

(three) stretch net

The number of screens and screen meshes should be selected flexibly according to the substrate, the printing method, and the nature of the printed materials. For finer printing, 130-150 mesh screens can be used. For printing thicker images, 100 can be selected. 120 mesh, gelatin paint film need to borrow the temperature on the version, can choose silk silk screen, lacquer film paper version of syrup, the upper version does not require temperature, so use nylon mesh as well.

Stretch the screen on the frame with a stretcher or hand-stitching method. The stretched screen should be flat and elastic, and clean the oil and dirt with glacial acetic acid on both sides of the screen.