Injection molding defects and anomalies are ultimately reflected in the quality of injection molded products.

The shortcomings of injection molding products can be divided into the following points:

(1) Insufficient product injection;

(2) Product overflow;

(3) Product dents and bubbles;

(4) The product has contact marks;

(5) The product is brittle;

(6) plastic discoloration;

(7) The product has silver wire, markings and flow marks;

(8) The product gate is cloudy;

(9) Product warping and shrinkage;

(10) The product size is not correct;

(11) Product paste mold;

(12) Material paste runner;

(13) Nozzle salivation.

The reasons and ways to overcome them are described below.

How to overcome the lack of injection of blow molding products

Insufficient product filling is often due to the material is cured before filling the cavity, of course, there are many other reasons.

⑴ Equipment reasons:

① hopper interrupt material;

② Partial or total blockage of the hopper neck;

③ The amount of feeding is not enough;

④ Feeding control system operation is not normal;

⑤ Plasticizing capacity of the injection press is too small;

⑥ Abnormal injection cycle caused by equipment.

⑵ Reasons for injection molding conditions:

① Injection pressure is too low;

(2) The injection pressure loss is too large during the injection cycle;

③ The injection time is too short;

④ the injection pressure time is too short;

⑤ The injection rate is too slow;

⑥ the material flow in the mold cavity is interrupted;

⑦ the filling rate is not equal;

⑧ Abnormal injection cycle caused by operating conditions.

(3) Temperature cause:

① Increase the barrel temperature;

② Increase the nozzle temperature;

③ Check millivoltmeters, thermocouples, resistance heating coils (or far-infrared heating devices) and heating systems;

④ Increase mold temperature;

⑤ Check the mold temperature control device.

⑷ Mold reason

① The flow channel is too small;

② The gate is too small;

③ The nozzle hole is too small;

④ Gate location is unreasonable;

(5) Insufficient number of gates;

⑥ cold material hole is too small;

⑦ insufficient exhaust;

⑧ Abnormal injection cycle caused by mold;

⑸ Material reason: material liquidity is too poor.

⒉ How to overcome product flash overflow:

Product overflow is often caused by mold defects, other reasons are: injection force is greater than mold locking force, material temperature is too high, insufficient exhaust, excessive feeding, mold with foreign bodies.

⑴ Mold problem:

(1) The cavity and core are not closed tightly;

② Cavity and core deviation;

③ The templates are not parallel;

④ template deformation;

⑤ the mold plane falls into foreign bodies;

⑥ insufficient exhaust;

⑦ The exhaust hole is too large;

⑧ Abnormal injection cycle caused by mold.

(2) Equipment problems:

(1) The projected area of the product exceeds the maximum injection area of the injection press;

② The injection press template is installed and adjusted incorrectly;

③ Mold installation is not correct;

④ the clamping force cannot be kept constant;

⑤ the molding machine template is not parallel;

⑥ Uneven deformation of tie rod;

⑦ Abnormal injection cycle caused by equipment

(3) Injection molding conditions:

① The clamping force is too low

② The injection pressure is too large;

③ The injection time is too long;

④ the injection pressure time is too long;

⑤ The injection rate is too fast;

⑥ mold filling rate is not equal;

The material flow in the mold cavity is interrupted;

⑧ Feed quantity control is too large;

⑨ Abnormal injection cycle caused by operating conditions.