Rupa colour inks manufacturing company supplying and exporting of Silk Screen printing inks used for foils, metals, CDs, T-shirt, plastics, PVC, Polyesters, polypropylene, acrylics, one sided PCBs, glass, paper, board, fabrics, Non woven fabrics, woven sacks, ceramics, corrugated boxes, ply wood, golf-ball, Shoes, slippers, keyboards, etc.
Screen printing inks are the most used modern printing inks technology today. Two types exist: rotary screen printing and flat (bed) screen printing. A blade squeezes the printing paste through openings in the screen onto the fabric. Line art and text may be printed onto the outer surfaces of a PCB by screen printing. When space permits, the screen print text can indicate component designators, switch setting requirements, test points, and other features helpful in assembling, testing, and servicing the circuit board.
Screen printing is also known as the silk screen, or, in one sided PCBs, the red print. Later some digital printing solutions have been developed to substitute the traditional screen printing process. This technology allows printing variable data onto the PCB, including serialization and barcode information for traceability purposes. Also some manufacturers tend to coat their boards in a thin layer of micro-film used to keep electricity from escaping the conductivity of the wire-strips.
Modern printing technology uses direct and indirect photo emulsions which are UV sensitive. This means that the artists’ renderings on transparent film can be exactly reproduced on the nylon screen coated with light sensitive (UV) emulsion. The light sensitive emulsion fills the entire screen and the transparent film upon which the artists sketch is laid upon the screen. And both are placed in the exposure unit. Where the light passes through the transparent film, the emulsion is exposed and hardens. Where the artists’ markings on the film stop the light, the emulsion is NOT exposed and released upon washing, creating a stencil on the screen that exactly reproduces the artists’ markings to the finest detail.
The screen is then placed on top of almost any substrate, paper, glass, fabric, golf balls, etc. Screen printing Ink is then placed across the top length of the screen. A squeegee (rubber blade) is used to spread the ink across the screen, over the stencil, and through the open mesh onto the paper/fabric below. The screen is lifted once the image has been transferred onto the paper/fabric, which is replaced with the next, unprinted, substrate. Colors are added layer by layer and each color requires a separate stencil on a separate screen. The screen can be re-used after cleaning.