Introduction of SMC/BMC molding raw materials

Molding is widely used in the following fields: Electrical: insulator, switch box, electrical equipment shell, insulation tools, wiring board, etc. , railway: vehicle window frame, toilet components, seats, table top, carriage wall and roof, etc. · Construction: water tanks, bath supplies, door panels, purification tanks, construction templates, etc. · Sanitary Ware: bathtubs, integrated bathroom equipment, one-piece shaped sink, etc. · and other industrial and agricultural fields.

Molding SMC raw materials SMC materials from GF (special yarn) , UP (Unsaturated Resin) , low shrinkage additives, MD (filler) and a variety of additives.

1. Unsaturated Polyester Resin

(1) easily reacts with thickener to meet the requirements of thickening (mainly for SMC)

(2) rapid curing, improved production efficiency

(3) high thermal strength, to ensure that the products are not damaged during demoulding (4) have enough toughness to avoid cracking when the parts have some deformation

2, Initiator, safe storage and operation; do not decompose at room temperature; the prepared SMC has a long storage period, when the temperature is reached, it is quickly decomposed and crosslinked. The dosage of initiator should be controlled, too much dosage: the molecular weight of the product is low, poor mechanical properties;. Too little, the product curing insufficient.

3. Inhibitor to prevent unsaturated polyester Resin from crosslinking polymerization at room temperature and prolong storage life.

4. The thickener SMC needs high viscosity in the process of press molding, storage and transportation (low viscosity is required in the preparation of SMC, and fiber is impregnated) . The viscosity change of SMC from production to use is controlled by thickener. Selection principles:

(1) in the preparation, required low viscosity, to ensure that the resin on Glass Fiber and filler full, impregnation,

(2) when the fiber and filler was impregnated, but also required rapid increase in viscosity, in order to adapt to storage and transport and mold,

(3) the thickened billet can rapidly fill the mold cavity at the molding temperature without segregation between the resin and the fiber.

(4) the viscosity of the thickened billet must be stable in the molding range during the storage period (5) the thickening effect should have stable repeatability in production.