How To Solve The Defect In The Product Gate Area?

An injection molding gate is a designed opening, usually small, that controls molten plastics flow into the mold cavity. There are various injection molding gate types, and using the right molding gate ensures the success of your injection molded parts. An injection molding gate design helps companies to manufacture plastic components with the best quality. This gate design controls the molten plastic machine from the runner. When there are errors in the injection mold gate design, there may be likely defects in the molded plastic components.

We have defects in the gate area during the injection molding process. In the design of the point gate perpendicular to the direction of the injection molded part, a radiation system composed of different color depths and glosses centered on the gate appears on the surface of the part during injection molding, called the ray line. There are basically three kinds of performance, namely dark lines on a dark background, dark lines on a dark background, and dark lines around the gate are dense and whitish. Most of these defects occur during the injection of polystyrene and modified polystyrene mixtures, and are related to the following factors: the two materials have differences in rheology, coloring, etc., the flow rate of the stratospheric and turbulent layers of the casting system, and there are differences in heating conditions; plastics are burned by thermal decomposition; gaseous substances interfere when plastics enter the mold.

Solution：

1. When using mixed plastic, the plastic should be mixed well, and the particle size of the plastic should be the same and uniform.

2. Plastic and colorant should be mixed evenly, if necessary, appropriate dispersant should be added and mixed mechanically.

3. The plasticization should be complete, and the plasticization performance of the machine should be good.

4. Reduce the injection molding pressure and speed, shorten the injection molding inject and pressure holding time, at the same time increase the mold temperature, increase the nozzle temperature, and reduce the front furnace temperature.

5. To prevent the melt and coking material from increasing the viscosity caused by the degradation of plastics: if pay attention to whether the screw and barrel are worn and there is a dead angle or the heating system is out of control, improper processing operation will cause the plastic to decompose due to long-term heating. The inner surface of the front end of the screw and barrel can be polished.

6.Improve the gate design, such as enlarge the gate diameter, change the gate position, change the gate to fillet transition, try to locally heat the gate, and add cold material well at the end of the runner.

Injection mold gate design is a crucial element in ensuring the quality of plastic mold quality and productivity. The right gate design may determine the difference between achieving perfect molds in contrast to defective ones. The right injection molding gate design helps reduce production costs and optimize cycle times.