Acrylic Injection Molding Process

Today, we are going to talk about the acrylic injection molding process.

Acrylic is chemically called polymethyl methacrylate (PMMA in English). Due to the shortcomings of PMMA surface hardness, easy scratching, low impact resistance, poor molding fluidity, etc., the modification of PMMA has appeared one after another. Such as the copolymerization of methyl methacrylate with styrene and butadiene, the blending of PMMA and PC, etc.

The flow of PMMA is worse than that of PS and ABS, and the melt viscosity is more sensitive to temperature changes. During the molding process, the melt viscosity is mainly changed from the injection temperature. PMMA is an amorphous polymer with a melting temperature greater than 160°C and a decomposition temperature of 270°C.

1. Plastic processing of the acrylic injection molding proess

PMMA has a certain degree of water absorption, with a water absorption rate of 0.3-0.4%, and the humidity of injection molding must be below 0.1%, usually 0.04%.

The presence of water causes bubbles, gas lines, and reduced transparency in the melt. So it needs to be dried. The drying temperature is 80-90