When processing injection molded parts, the in mold injection molding processing factory sometimes has insufficient filling, which leads to the quality problem of injection molded products and usually brings great property losses to the injection molding factory. Therefore, the operator of the injection molding factory must know how to improve and solve the problem when the filling is insufficient

1. Improper adjustment of feeding, shortage or excessive feeding

Improper feeding metering or abnormal operation of the feeding control system, abnormal injection cycle caused by the molding machine or mold or operating conditions, small backpressure of the blank or small particle density in the barrel will cause material shortage. For larger particles, particles with larger porosity, plastics with crystallinity greater than the conversion rate, such as polyethylene, polypropylene, nylon, etc., and viscous plastics, such as ABS, when the material temperature is high, it needs to be adjusted to adjust the material consumption

When there are too many materials stored at the end of the barrel, the screw will reduce the injection pressure that costs too much during the injection molding process and push the excess materials stored in the barrel, thus greatly reducing the effective injection pressure of the plastic into the mold cavity, so that the goods cannot be filled

2. The oil pump pressure is too low, the oil pump time is short, and the plunger or screw returns too early

Melted plastic has high viscosity at low temperature and poor circulation. High pressure and high speed injection shall be adopted. For example, when the injection molding manufacturer manufactures ABS colored parts, the high temperature resistance of the colorant limits the heating temperature of the barrel, which should be compensated by higher injection pressure and longer injection time than normal

3. The material temperature is too low

The temperature of the rear end of the barrel is low, and the solute entering the mold cavity rises to the extent that it cannot flow due to the cooling effect of the mold, which hinders the filling of the far end of the mold; The temperature at the front end of the barrel is low, and the plastic with strong viscosity is difficult to flow, which hinders the forward movement of the round corner, resulting in sufficient pressure indicated by the barometer, but the pressure of solute entering the mold cavity is low and the speed is slow

When the filling of injection molded parts is insufficient, it is essential to take corresponding measures in time. Inadequate filling is one of the problems often encountered in the injection molding process, so the plastic injection molding manufacturers will provide real-time training for injection molding operators