排气系统是注塑模具结构的基本组成之一，排气在注塑成型过程中是个重要问题，如果不及时排出气体，这些气体积存在型腔内后，形成积垢，会污染注塑模具，降低模具使用寿命。那么注塑模具为什么要设置排气系统？济南注塑加工厂家为您讲解问题。

The exhaust system is one of the basic components of the injection mold structure. Exhaust is an important problem in the injection molding process. If the gas is not discharged in time, the gas volume will be accumulated in the mold cavity, which will pollute the injection mold and reduce the service life of the mold. Then why should the injection mold be equipped with an exhaust system? Jinan injection molding factory will explain the problems for you.

设置排气系统的目的

Purpose of setting exhaust system

1、在熔融塑料材料的注射过程中，从塑料注射模腔中排出空气。

1. During the injection of the molten plastic material, air is discharged from the plastic injection mold cavity.

2、去除注塑加工过程中产生的各种气体。

2. Remove all kinds of gases generated during the injection molding process.

排气不顺的危害

Hazards of unsmooth exhaust

1、熔体充填困难

1. Difficult melt filling

在注塑加工过程中，熔体将取代型腔中的气体，如果气体排出不及时，将会造成熔体充填困难，导致注射量不足而不能充满型腔。

In the process of injection molding, the melt will replace the gas in the cavity. If the gas is not discharged in time, it will cause difficulty in filling the melt, resulting in insufficient injection volume and unable to fill the cavity.

2、造成质量缺陷

2. Cause quality defects

排出不畅的气体会在型腔内形成高压，并在一定的压缩程度下渗入塑料内部，造成气孔、空洞，组织疏松、银纹等质量缺陷。

The gas that is not discharged smoothly will form high pressure in the mold cavity and penetrate into the plastic under a certain degree of compression, resulting in quality defects such as pores, voids, loose tissues and crazes.

3、局部碳化和烧焦

3. Local carbonization and charring

由于气体被高度压缩，使得型腔内温度急剧上升，进而引起周围熔体分解、烧灼，使塑料件出现局部碳化和烧焦现象。它主要出现在两股熔体的合流处及浇口凸缘处。

As the gas is highly compressed, the temperature in the mold cavity rises sharply, which causes the surrounding melt to decompose and burn, causing local carbonization and burning of the plastic parts. It mainly occurs at the junction of two melts and the gate flange.

4、塑件力学性能降低

4. The mechanical properties of plastic parts are reduced

气体的排除不畅，使得进入各型腔的熔体速度不同，因此易形成流动痕和熔合痕，并使塑料件的力学性能降低。

The gas is not discharged smoothly, which makes the melt speed into each cavity different, so it is easy to form flow marks and fusion marks, and reduce the mechanical properties of plastic parts.

5、注塑成型困难

5. Difficult injection molding

注塑模具排气不良，型腔中的气体受到压缩，产生很大的反压力，正是这种反压力阻止了熔融塑料的正常快速充模，降低充模速度，使得注塑成型变得困难。遇到这种情况注塑人员常采用提高注塑压力的方法，这样就导致了保压时间延长，成型周期延滞，生产效率降低，注塑机耗能增加等后果。

The gas in the mold cavity is compressed due to poor exhaust of the injection mold, resulting in great back pressure. It is this back pressure that prevents the normal and rapid filling of molten plastic, reduces the filling speed, and makes injection molding difficult. In this case, the injection molding personnel often adopt the method of increasing the injection pressure, which leads to the extension of the pressure holding time, the delay of the molding cycle, the reduction of the production efficiency, and the increase of the energy consumption of the injection molding machine.

以上内容中可以看出设置排气系统还是非常重要的。本公司具有多年品质经验积累，从设计到成品提供全套精密注塑模具的加工，交货周期短，用心服务每位客户，如果您有需求，欢迎来关注我们网站http://www.sdlqmj.com随时联系我们。

It can be seen from the above that it is very important to set the exhaust system. The company has many years of quality experience, from design to finished products to provide a complete set of precision injection mold processing, short delivery cycle, and dedicated service to each customer. If you have any needs, please visit our website http://www.sdlqmj.com Feel free to contact us.