Screen printing process technology and detailed operation (1)

First, the screen printing process preparation

1. Screen printing plate selection

The screen frame used for screen printing is made of wood and made of aluminum alloy. The size and material of the screen frame play an important role in the quality of the screen. No matter which kind of material is selected, the frame should be resistant to the screen frame. Stretch, strength, light weight, and ease of use are the conditions of choice.

2. Screen selection

The screens used for screen printing include cotton yarn, silk, polyester, stainless steel wire, copper wire and other metals. In the weaving form, they are divided into corrugated weaving, braided weaving and semi-twist weaving. There are monofilaments and multifilaments in the way they are represented. The commonly used mesh and models sold in the market are indicated. The number of screens and screens should be selected according to the substrate, the plate making method, the nature of the printing materials, the quality of the printed products and the customer's requirements. Usually, fine screen products with a size of 200 mesh or more are selected for the printing of fine products.

3. Stretch net

The stretch net is generally a wooden net frame stretch net that is manually completed, and the aluminum alloy net frame is usually made by a pneumatic stretch net stretcher. Screen and tension are determined by the screen printing pressure, the precision of the printing products and the stretching stretchability of the screen. Too high tension will cause the screen to be damaged, the printing will not bear the printing, and the tension will be too low to cause misprints. The ideal stretch net should be flat and centered, with even tension and moderate elasticity, so as to ensure the best print quality.

4. Screen pretreatment

The pre-treatment of the wire mesh refers to degreasing and roughening the stretched polyester wire mesh in the wire mesh frame, that is, degreasing and then grinding the mesh. Degreasing and roughening treatment, ie degreasing and grinding. The degreasing treatment is generally cleaned with a brush, glacial acetic acid or a medium-sized detergent to eliminate grease and dirt on both sides of the screen, so as to avoid thinning of the film when the photosensitive adhesive is applied, causing pinholes and the like to fail. The hair treatment is to apply the grinded plaster on the screen of the frame, brushing it evenly on the front and back sides of the frame with a brush, so that the surface of the screen becomes rough, so as to improve the adhesion and adhesion of the film and the screen.

After the degreasing and shading treatment of the screen mesh frame, thoroughly washed with clean water first clean and dry, stored in a cool dry place, to ensure that the equipment used in plate making