Injection molded parts are the general name of injection molded products produced and processed by injection molding machines, which are applied in many industries. However, in the process of design and processing, in order to ensure the quality of products, there are many precautions. Let's share it with you.

1、设计注意事项

1. Design considerations

为了防止因回流不畅或冷却不均而导致塑料成型不好，进而引起产品表面缺陷，在设计时要注意以下几点：

In order to prevent poor plastic molding due to poor reflux or uneven cooling, and then cause product surface defects, the following points should be paid attention to in the design:

（1）模具表面应光洁，粗糙度低（尽量低于0.8）；

(1) The surface of the die shall be smooth with low roughness (lower than 0.8 as far as possible);

（2）壁厚尽量均匀，脱模斜度要足够大；

(2) The wall thickness shall be as uniform as possible, and the demoulding slope shall be large enough;

（3）除PET外，壁厚不要太薄，一般不能低于lmm；

(3) Except pet, the wall thickness should not be too thin, generally not less than LMM;

（4）浇口、流道要尽可能宽大、粗短，且应根据收缩冷凝过程设置浇口位置，必要时应加冷料井；

(4) The gate and runner shall be as wide and short as possible, and the gate position shall be set according to the shrinkage and condensation process, and the cold charging well shall be added if necessary;

（5）排气孔槽一定要足够，以便于及时排出空气和熔体中的气体；

(5) The vent slot must be sufficient to discharge the air and gas in the melt in time;

（6）注塑件的过渡部分应圆滑，并逐步过渡，防止有尖角、锐边产生，特别是PC产品一定不能有缺口。

(6) The transition part of injection molded parts shall be smooth and transition gradually to prevent sharp corners and sharp edges, especially PC products must not have gaps.

2、注塑工艺注意事项

2. Precautions for injection molding process

（1）注射速度：在满足充模的情况下，一般宜低，尽量采用慢一快一慢的多级注射；

(1) Injection speed: when the mold filling is satisfied, it should generally be low, and multi-stage injection of slow, fast and slow should be adopted as far as possible;

（2）应选用专用螺杆、带单独温控射咀的注塑机进行加工；

(2) Special screw and injection molding machine with separate temperature control nozzle shall be selected for processing;

（3）螺杆转速和背压：在满足塑化质量的前提下，应尽量低，防止产生解降；

(3) Screw speed and back pressure: on the premise of meeting the plasticization quality, it shall be as low as possible to prevent degradation;

（4）注射压力：一般较高，以克服熔料粘度大的缺陷，但压力太高会产生内应力造成脱模因难和形变；

(4) Injection pressure: generally high to overcome the defect of high melt viscosity, but too high pressure will produce internal stress, resulting in difficult demoulding and deformation;

（5）保压时间和成型周期：在满足产品充模，不产生凹陷、气泡的情况下，应尽量短，以减低熔料在机筒停留时间；

(5) Pressure holding time and forming cycle: it shall be as short as possible to reduce the residence time of molten material in the barrel under the condition of meeting the product mold filling and no depression and bubble;

（6）注射温度在塑料树脂不分解的前提下，宜用较高注射湿度；

(6) Under the premise that the plastic resin does not decompose, the injection temperature should use higher injection humidity;

（7）模具温度：注塑件冷却的好坏，对质量的影响非常大，所以模温一定要能准确控制其过程，有可能的话，模温尽量高一些比较好。

(7) Mold temperature: the cooling of injection molded parts has a great impact on the quality, so the mold temperature must be able to accurately control the process. If possible, it is better to have a higher mold temperature as much as possible.