Feb 01,2021

How to choose printing plate paint

Primer types and film thickness There are four types of primers: epoxy resin, polyester resin, acrylic resin and polyurethane resin. Generally, primers are selected according to the product's end use, use occasion, processing level, and top coat. The film thickness of the primer is usually 5um. 1, epoxy primer Good adhesion to the substrate, water resistance, alkali resistance, and chemical resistance. It is the earliest primer for coils, and its flexibility is not as good as other primers. 2, polyester bottom Good adhesion to the substrate, excellent flexibility, more sensitive to humid environments, and less chemical resistance than epoxy primer. 3, water-soluble acrylic primer Good adhesion to the substrate, excellent flexibility, low organic solvent content, low temperature curing, not suitable for storage in a humid environment, and high pretreatment requirements. 4, polyurethane primer It has chemical resistance, abrasion resistance, durability and flexibility. Top coat type and film thickness The most commonly used topcoats are polyester, silicon modified polyester, polyvinyl chloride plastisol and polyvinylidene fluoride. 1, polyester Good adhesion, wide range in formability and outdoor durability, and moderate chemical resistance. 2, silicon modified polyester The coating film has good hardness, abrasion resistance and heat resistance, as well as good outdoor durability and non-chalking, limited gloss retention and flexibility, and medium to high cost. 3, polyvinylidene chloride has good moldability and color retention, excellent outdoor durability and chalking resistance, solvent resistance, limited color, and expensive. 4, polyvinyl chloride plastisol Excellent external durability, chemical resistance, damage resistance, beautiful appearance, special primer is required. The surface can have a smooth surface, which can be used for compression or automatic shrinkage to form patterns. The thickness of the coating is generally greater than 100um. Except for plastisols, under normal circumstances, the coating thickness of the primer and the topcoat is >=20um, and the performance of the product can achieve the intended purpose.