Several Common Problems and Solutions of ​injection Plastic Parts

Ⅰ. Reasons for deformation of injection plastic parts and solutions

The molded part has a shape similar to the cavity but is a distorted version of the cavity shape.

(a) possible causes of problems

1. Bending is because there is too much internal stress in the injection plastic parts

2. The mold filling speed is slow.

3. The plastic in the mold cavity is insufficient.

4. Plastic temperature is too low or inconsistent.

5. The injection plastic parts are too hot when they are pushed out.

6. Insufficient cooling or inconsistent temperature of moving and fixed mold.

7. The structure of the injection plastic parts is not reasonable (such as the reinforcement is concentrated on one side, but far away from each other).

(2) Remedial methods

1. Reduce injection pressure.

2. Reduce the screw forward time.

3. Increase cycle time (especially cooling time). After ejection from the mold (especially the thicker injection plastic parts), the injection plastic parts are immediately immersed in warm water (38℃) to cool slowly.

4. Increase the injection speed.

5. Increase the temperature of the plastic.

6. With cooling equipment.

7. Appropriate increase the cooling time or improve the cooling conditions, as far as possible to ensure that the mold temperature of moving and fixed mold is consistent.

8. Improve the structure of plastic injection molding parts according to the actual situation.

Ⅱ. Common problems in the process of injection transparent injection plastic parts

Transparent plastic because want to high light transmittance, inevitable requirement strict plastic products surface quality, without any markings, porosity, white fog, dizzy, defects such as poor black spots, color and luster, thus in the injection molding process for raw materials, equipment, the design of the mould and products, will be very attention and strict even special request.

Secondly, due to the high melting point and poor fluidity of transparent plastic, in order to ensure the surface quality of the product, often need a higher temperature, injection pressure, injection speed and other process parameters also need to be slightly adjusted, so that the injection of plastic can be filled with mold, and will not produce internal stress and cause product deformation and cracking.

Therefore, from the raw material preparation, equipment and mold requirements, injection molding process and product raw material processing several aspects to carry out strict operation.

Ⅲ. Common problems of color difference control of injection plastic parts

Chromatic aberration is a common defect in injection molding. There are many influencing factors of chromatic aberration, involving raw material resin, masterbatch, mixing of chromatic aberration with raw material, injection molding process, injection molding machine, etc. In the actual production process, we generally control chromatic aberration from the following five aspects.

1. Preparation and drying of raw materials;

2. Preparation and drying of raw materials;

3. Reduce the influence of cartridge temperature on color difference;

4. Reduce the impact of injection molding process adjustment;

5. Master the influence of cartridge temperature and master quantity on product color change.