- Polyester / Nylon porous cloth pneumatically stretched tightly over an aluminium frame. Proper tension is essential to accurate color registration and less consumption of ink.
- The stretched cloth is chemically treated with Auto prep gel to degrease the cloth, then further it is treated with Universal mesh prep to abrade the cloth for better hold of emulsion over the cloth
- Emulsion (image creating photopolymer liquid) is coated over above treated screen
- Positive with the image is exposed over the photo-sensitised emulsion through a metal halide lamp.
- A stencil ( with the printing area ) is produced on the screen photochemically.
- Print with manual or mechanical process
For printing we have with us following inks :
- Winson inks for Footwear Industry – Solvent and Water based
- Encres Dubuit for Smart Cards, POP, Front Panels, Perfumes, Flasks, Bottles,Packaging and Labels
- Proll inks for IMD, Membrane switches, 3D forming
Post Press and finishing
– Screen cleaning
– Screen reclamation
Screen printing is arguably the most versatile of all printing processes, a greater thickness of the ink can be applied to the substrate that is not possible with other printing techniques. It can be used to print on a wide variety of substrates, including paper, plastics, metals, footwear materials, PU/PVC sheet, fabrics, and many other materials.
The major chemicals used include :
- Auto prep gel ( to degrease the marks during handling and manufacturing )
- Universal mash prep ( to abrade and make the polyester mesh ready to adhere emulsion properly and for long time )
- Screen emulsion ( the photosensitive material )
- Inks, resins and solvents
- Surfactants and additives
- Caustics and oxidizers used in screen reclamation
Screen printing ink is applied to the substrate by placing the screen over the material to be printed. Ink with a paint-like consistency is placed onto the top of the screen. Ink is then forced through the fine mesh openings using a squeegee that is drawn across the screen, applying pressure, thereby, forcing the ink through the open areas of the screen. Ink will pass through only in areas where no stencil (non printing area) is applied, thus forming an image on the printing substrate. The diameter of the threads and the thread count of the mesh along with the stencil coating thickness will determine how much ink is deposited onto the substrates.
The lift off between the screen and substrate decides the proper and sharp image of ink to be printed.
Many factors such as size and form, angle, pressure, and speed of the squeegee determine the quality of the impression made by the squeegee.
The squeegee made from polyurethane can produce more impressions without significant degradation of the image.