With the rapid development of injection molding industry, people have higher and higher requirements for the surface quality and dimensional accuracy of various plastic products, especially the plastic products used as pure structural parts in different engineering technologies. In order to meet their different physical and mechanical properties, the main requirements are dense structure, firm fusion High strength and low internal stress. But in the process of injection mold testing, and then adjust the parameters of injection molding process, the products often appear various phenomena, such as insufficient filling, high internal stress and surface streamline, which is mainly due to the problem of the exhaust of the mold. During the injection molding process of the mold, various gases generated in the mold mainly come from the following sources: there is air in the mold cavity and gating system; Water vapor formed by evaporation of water contained in plastic raw materials at injection temperature; Gas produced by plastic decomposition at high temperature;

在注塑的時候塑料中一（yī）些添（tiān）加劑揮發掉（diào）後或者一些（xiē）熱固性塑料（liào）成形過程中交聯反應（yīng）所生成的氣體。同時在要保證注射成形的過程中要完整的脫模進行（háng），減少製品（pǐn）的成形缺陷，我們再考慮如何提高其質量的注射加（jiā）工工藝的同時，還一定重視（shì）其模具排出多餘氣體的係統的設計。

During injection molding, the gas generated by cross-linking reaction after some additives in plastics volatilize or during the forming of thermosetting plastics. At the same time, in order to ensure the complete demoulding in the process of injection molding and reduce the forming defects of products, we should not only consider how to improve the injection processing technology of its quality, but also pay attention to the design of the system for discharging excess gas from its mold.

在注塑模（mó）具的過程中，如模具排氣不好，型腔（qiāng）中的氣體受到壓縮將產生（shēng）很大的背壓，大的（de）阻礙了塑料熔體的正（zhèng）常快速充模，使注塑變得困（kùn）難；同時會迫使注（zhù）射時壓力不斷（duàn）提高，保壓時間增加，成形周（zhōu）期延長，生產注塑件的（de）時候效率也不停降低。有時候腐蝕性的氣體在型腔表麵形成積垢，降低了模具正常使用下的壽（shòu）命。

In the process of injection mold, if the mold exhaust is not good, the gas in the mold cavity will be compressed, which will produce a great back pressure, which greatly hinders the normal and rapid filling of plastic melt, making injection molding difficult; At the same time, it will force the continuous increase of pressure during injection, the increase of pressure holding time, the extension of forming cycle, and the continuous reduction of efficiency in the production of injection molded parts. Sometimes corrosive gas forms scale on the surface of the cavity, which reduces the service life of the die under normal use.

在注塑機塑料充模的過程中，為了將熔融（róng）的塑料的流動性保持在好的狀（zhuàng）態，因此必須（xū）要提高在熔融塑（sù）料的溫度和注射壓力，但也因為這樣製品的殘餘應力會隨之壓力而提高，產品四（sì）周的翹曲和塑（sù）料裂解的可能性也增加。比方模具的排（pái）氣（qì）正（zhèng）常情況下，注（zhù）射速度可提高，充填（tián）和保壓可容易達到好的狀態（tài），不需額外增（zēng）加料筒和噴嘴的溫度。這樣（yàng）製品的殘（cán）餘應力（lì）小，翹曲（qǔ）變形小。注塑加工時候（hòu）我們也要考慮（lǜ）如何排氣，好的排氣係統（tǒng）會提交塑料件的質量。

During the plastic filling process of the injection molding machine, in order to maintain the fluidity of the molten plastic in a good state, it is necessary to increase the temperature and injection pressure of the molten plastic, but also because the residual stress of the product will increase with the pressure, and the possibility of warpage and plastic cracking around the product will also increase. For example, under normal conditions, the injection speed can be improved, and the filling and pressure holding can easily reach a good state without increasing the temperature of the barrel and nozzle. In this way, the residual stress of the product is small and the warpage deformation is small. During injection molding, we should also consider how to exhaust. A good exhaust system will submit the quality of plastic parts.