What are the common test problems of injection mold?

Process problems: too low plasticizing temperature, too low nozzle temperature, too short injection time, too slow injection speed and too low mold temperature;

Mold problems: the runner is too small, the gate is too small, the gate position is unreasonable, the exhaust is not smooth, and there are impurities in the cavity;

Raw material problems: poor fluidity and many impurities.

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Process problems: too high plasticizing temperature, too long injection time, too much feeding, too high injection pressure, too high mold temperature and sundries between templates;

Mold problems: mold deformation, size matching error between core and cavity, non-parallel template combination and too deep exhaust groove;

Equipment problems: the templates are not parallel, and the templates are not tightly closed;

Raw material problem: excess liquidity.

3. Deformation

Technological conditions: the material temperature is too high, the mold temperature is too high, the heat preservation time is too short, and the cooling time is too short to force demoulding;

Mould aspect: improper gate position, insufficient number of gates and improper ejection position make the stress uneven.

4. Wave flow marks

Process conditions: too low material temperature, too low injection speed, too low injection pressure, insufficient pressure holding, too low mold temperature and insufficient injection quantity lead to incomplete plasticization;

Mould: too few gates, rough runner gates and poor surface finish;

Equipment: system failure, oil pump pressure drops after temperature control;

Raw materials: too many volatiles, poor fluidity, mixed with impurities.

5. Bubbles

Process conditions: low injection pressure, insufficient holding pressure, insufficient holding time and high material temperature;

Mold: poor exhaust, unreasonable gate position and too small gate size;

Raw materials: the moisture is not dried or the drying time is not enough, and the shrinkage rate is too large.

Shrinking depression

Process conditions: insufficient feeding, too short injection time, too short holding time, too high material temperature, too high mold temperature and too short cooling time;

Mould aspect: runner is too small, gate is too small, and exhaust is poor;

Equipment: the injection pressure is not enough, and the nozzle is blocked by foreign objects;

Raw materials: shrinkage rate is too large.

7. Unstable size

Process conditions: injection pressure is too low, barrel temperature is too high, holding time changes, injection cycle is unstable, and mold temperature is too high;

Mold: uneven gate size, inaccurate cavity size, loose core, too high mold temperature or no water channel;

Raw materials: change the brand and variety, the particle size is uneven and contains volatile substances.

8. Difficult demoulding

Process conditions: too high injection pressure, too long holding time, too large injection volume and too high mold temperature;

Equipment: insufficient jacking force and jacking distance;

Mould aspect: there is no draft angle, insufficient finish, inappropriate ejection mode, inappropriate matching accuracy, poor exhaust and template deformation.

9. Silver stripes

Process conditions: the material temperature is too high, the injection speed is too fast, the injection pressure is too high, the plasticization is uneven, and there is too much release agent;

Mold: the gate is too small, the mold finish is poor, and the exhaust is poor;

Equipment: the back pressure is too low, and the nozzle has castings;

Raw materials: moisture content is not dry, and lubricant is excessive.

10. Burning

Process conditions: the material temperature is too high, the injection pressure is too high, the speed is too fast, the downtime is too long, and the release agent is not clean;

Mould aspect: the gate is too small, the exhaust is not smooth, the cavity is complex and the finish of the cavity is poor;

Raw materials: raw materials are mixed with impurities, and granular materials contain powder.

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Process conditions: the material temperature is too high, the injection pressure is too high, the molding cycle is long, the mold is not cooled, and the nozzle temperature is high;

Mould aspect: the gate is too small;

Equipment: There are obstacles in the barrel or nozzle, and the screw speed is high. The core is not concentric with the nozzle center;

Raw materials: material pollution, colorant decomposition and high volatile matter content.

12. Welding trace

Process conditions: low injection pressure, short injection time, low material temperature, excessive clamping force and inappropriate release agent;

Mold: the mold temperature is too low, the runner is small, the gate position is wrong, and the exhaust is not smooth;

Equipment: poor plasticization;

Raw materials: poor fluidity, too much lubricant and foreign matter.

13. gloss defect

Process conditions: low material temperature or mold temperature, low injection pressure, too high or too low injection speed and too short cooling time;

Mould: the roughness of the mould becomes larger, the gate is too small, the runner is too thin and the exhaust is not smooth;

Equipment: insufficient supply;

Raw materials: raw materials are not dried or contain volatile substances, which are easy to degrade, and additives or release agents are used too much or of poor quality and contain foreign substances.