The shrinkage in the blocking direction is always less than that in the unblocked direction, and the shrinkage near the insert is less than that far away from the insert. The shrinkage of products with complex shape is smaller than that of products with simple shape. There is also a significant difference between the flow direction and the contraction perpendicular to the flow direction. Generally speaking, the contraction in the flow direction is greater than that in the flow direction. The following is a detailed description of the factors affecting the shrinkage of Jinan self sealing bags.

　　其次要说的是提高自封袋模具的温度，一般会增加收缩率，特别是对于结晶塑料。延长保温时间可降低收缩率。但一旦浇口关闭，延长保温时间将不再影响收缩率。

　　The second thing to say is to increase the temperature of the self sealing bag mold, which will generally increase the shrinkage, especially for crystalline plastics. The shrinkage can be reduced by prolonging the holding time. However, once the gate is closed, extending the holding time will no longer affect the shrinkage.

　　还有一点是，增大压力会导致塑料拉链袋密度增大，从而使收缩率降低。提高材料的温度会使产品的体积膨胀，减少进入腔体的材料。然而，材料温度的升高会降低粘度，但有利于压力向空腔的传递，降低收缩率，收缩率取决于上述两种效应的综合影响。一般塑料的粘度是对温度变化敏感的，是后者。

　　Another point is that increasing the pressure will increase the density of the plastic zipper bag, thus reducing the shrinkage. Increasing the temperature of the material will expand the volume of the product and reduce the material entering the cavity. However, the increase of the material temperature will reduce the viscosity, but it is conducive to the transfer of pressure to the cavity and reduce the shrinkage, which depends on the combined effect of the above two effects. The viscosity of general plastics is sensitive to temperature change, which is the latter.

　　以上是济南自封袋厂家小编为大家介绍的相关内容，想要了解更多内容，欢迎访问网站：//www.haaimobile.com

　　The above is the relevant content introduced by Jinan self sealing bag manufacturer. If you want to know more, please visit the website: //www.haaimobile.com