[中文]制品成型尺寸精度低

注塑件缺陷的特征

一﹐注塑过程中重量尺寸的变化超过了模具、注塑机、塑料组合的生产能力。

二、可能出现问题的原因

(1).输入射料缸内的塑料不均。

(2).射料缸温度波动的范围太大。

(3).注塑机容量太小。

(4).注塑压力不稳定。

(5).螺杆复位不稳定。

(6).运作时间的变化、溶液黏度不一致。

(7).注射速度（流量控制）不稳定。

(8).使用了不适合模具的塑料品种。

(9).考虑模温、注射压力、速度、时间和保压等对产品的影响。

三、补救方法

(1).检查有无充足的冷却水流经料斗喉以保持正确的温度。

(2).检查是否劣质或松脱的热电偶。

(3).检查与温度控制器一起使用的热电偶是否属于正确类型。

(4).检查注塑机的注塑量和塑化能力，然后与实际注塑量和每小时的注 塑料用量进行比较。

(5).检查是否每次运作都有稳定的熔融热料。

(6).检查回流防止阀有否泄露，若有需要就进行更换。

(7).检查是否错误的进料设定。

(8).保证螺杆在每次运作复回位置都是稳定的，即不多于0.4mm的变化。

(9).检查运作时间的不一致性。

(10).使用背压。

(11).检查液压系统运作是否正常，油温是否过高或过低（25—60′C）。

(12).选择适合模具的塑料品种（主要从缩率及机械强度虑）。

(13).重新调整整个生产工艺。

[/中文]

[外文]Poor precision in molding size

I. Features of injection molding defects

The precision in weight and size required for injection molding goes beyond the combined capability of mold, injection machine and plastic.

II. Possible Causes

(1) Uniform materials in the barrel.

(2) Too large fluctuation of barrel temperature.

(3) Too small injection machine capacity.

(4) Non-consistent injection pressure.

(5) Non-consistent screw resetting

(6) Non-consistent running time change or melt viscosity

(7) Non-consistent injection speed (flow controlling)

(8) Plastic variety not fit for this mold has been used.

(9) Considering the influence of mold temperature, injection pressure, speed , time and holding pressure to the product.

III. Remedies

(1) Check whether sufficient cooling water is available at the throat of hopper to ensure proper temperature.

(2) Check whether the thermocouple comes off or is of poor quality.

(3) Check whether the thermocouple is of proper type or not?

(4) Check the injection amount and plasticizing capacity of injection machine and compare it with the actual injection amount and hourly material consumption.

(5) Check whether consistent melts produced in each run?

(6) Inspect the check valve for leakage. If yes, replace it.

(7) Check whether the material feeding parameter is proper or not?

(8) Ensure the screw remains at the same position after each running and resetting, i.e. not more than 0.4mm of change.

(9) Check for inconsistency in running time.

(10) Use backing pressure.

(11) Check the hydraulic system to be sure it′s normal. Check the oil temperate to be sure it′s within specified range (25-60℃)

(12) Select a plastic variety fit for this mold (Shrinkage rate and mechanical strength are major concerns )

(13) Vary the whole production process accordingly.

[/外文]