Zaojie material -- Application of thickener for SMC sheet

The following points must be paid attention to when applying thickener to SMC sheet:

a. During preparation, the viscosity increase rate is required to be very low to ensure the full infiltration of the resin on the glass fiber and filler.

b. The thickened billet, when the molding temperature is low, can have enough fluidity under the appropriate pressure to ensure that the mold is fully filled. When the glass fiber and filler are infiltrated, the adhesive speed is required to increase, so as to fit into the mold for molding operation as soon as possible. And keep each piece of sheet mold plastic do not have firm adhesion.

c. The thickened billet, when the molding temperature is high, can make the glass fiber flow to the mold everywhere, and the resin and the glass fiber do not separate.

d. When the glass fiber and filler are infiltrated, the viscidity rate is required to increase, so as to fit into the mold for molding operation as soon as possible. And keep each piece of sheet mold plastic do not have firm adhesion. The thickened billet, when the molding temperature is high, can make the glass fiber flow to the mold, and the resin and the glass fiber do not separate.

e. The viscosity after thickening must be stable during the storage period and kept within the viscosity range that can be moulded.

The thickening action of SMC sheet should have stable reproducibility in each batch production. Thickener generally refers to chemical thickening compounds, which account for about 3% in reinforced mold plastics. There are many kinds of thickener, the preparation of polyester reinforced plastic, the most commonly used thickener for magnesium oxide, zinc oxide and magnesium hydroxide, but zinc oxide and resin mixed, easy to produce turbidity, and a large number of precipitation.