Screen printing is often utilized as a secondary processing method for plastic surfaces, in comparison to other substrates. This secondary processing can be essential to overcome limitations and enhance the aesthetic appeal of plastic products. Presently, screen printing has the capability to print on plastic products with varying surface textures, degrees of hardness, and shapes. Consequently, it is extensively employed for decorating plastic packaging films and containers.
In the context of screen printing, the ink used for plastic printing differs from that used for paper and cannot be intermixed. Plastic resins, including polyamide, synthetic solvents, organic solvents, and colorants, are blended to modify inks for most plastic surfaces.
In all screen printing processes, a substrate and a framed screen with the desired graphic are required. The silkscreen mesh on the screen frame allows the ink to pass through the mesh in the image area while blocking the non-image area. In plastic printing, the ink is poured onto one end of the screen printing screen, and a squeegee is used to push the ink film to the opposite end of the screen. The ink is then scraped through the screen mesh onto the plastic substrate to create the desired image and text.
Certain plastic parts may require supplementary equipment besides the appropriate ink. For instance, for large signs and pallets, a vacuum pallet may be necessary to keep flat substrates in place during printing. Since items printed with air-dry inks require additional curing time, they need extra storage space while they dry. A drying rack can help ensure that they don’t occupy an excessive amount of workshop space.