排氣系統是注塑模具結構的基本組成之一，排氣在注塑成型過程中是個重要問題，如果不及時排出氣體，這些氣體積存在型腔內后，形成積垢，會污染注塑模具，降低模具使用壽命。那么注塑模具為什么要設置排氣系統？
濟南注塑加工廠家為您講解問題。
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.
設置排氣系統的目的
Purpose of setting exhaust system
1、在熔融塑料材料的注射過程中，從塑料注射模腔中排出空氣。
1. During the injection of the molten plastic material, air is discharged from the plastic injection mold cavity.
2、去除注塑加工過程中產生的各種氣體。
2. Remove all kinds of gases generated during the injection molding process.
排氣不順的危害
Hazards of unsmooth exhaust
1、熔體充填困難
1. Difficult melt filling
在注塑加工過程中，熔體將取代型腔中的氣體，如果氣體排出不及時，將會造成熔體充填困難，導致注射量不足而不能充滿型腔。
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、造成質量缺陷
2. Cause quality defects
排出不暢的氣體會在型腔內形成高壓，并在一定的壓縮程度下滲入塑料內部，造成氣孔、空洞，組織疏松、銀紋等質量缺陷。
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、局部碳化和燒焦
3. Local carbonization and charring
由于氣體被高度壓縮，使得型腔內溫度急劇上升，進而引起周圍熔體分解、燒灼，使塑料件出現局部碳化和燒焦現象。它主要出現在兩股熔體的合流處及澆口凸緣處。
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、塑件力學性能降低
4. The mechanical properties of plastic parts are reduced
氣體的排除不暢，使得進入各型腔的熔體速度不同，因此易形成流動痕和熔合痕，并使塑料件的力學性能降低。
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、注塑成型困難
5. Difficult injection molding
注塑模具排氣不良，型腔中的氣體受到壓縮，產生很大的反壓力，正是這種反壓力阻止了熔融塑料的正常快速充模，降低充模速度，使得注塑成型變得困難。遇到這種情況注塑人員常采用提高注塑壓力的方法，這樣就導致了保壓時間延長，成型周期延滯，生產效率降低，注塑機耗能增加等后果。
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.
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.520che.com.cn Feel free to contact us.
