The shrinkage rate of self sealing bag in the blocked direction is always smaller than that in the unimpeded direction, and the shrinkage near the insert is less than that far away from the insert. The shrinkage of simple shape products is less than that of complex products. There are also obvious differences between the flow direction of self sealing bag and that perpendicular to the flow direction. Generally, the shrinkage rate in the flow direction is greater than that in the vertical direction. The factors influencing the shrinkage of self sealing bags are described in detail below.

其次要說(shuō)的是提高自封袋模具溫度，一般會(huì)使收縮率增大，特別是對(duì)于結(jié)晶型塑料。延長(zhǎng)保壓時(shí)間，可以使收縮率減小。但是一旦澆口已經(jīng)封閉，再延長(zhǎng)保壓時(shí)間便不再會(huì)對(duì)收縮率有影響。

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

后還有一點(diǎn)就是提高壓力可以導(dǎo)致塑料自封袋密度增加，使收縮率減小。提高物料溫度，會(huì)使制品體積膨脹而佼壓入型腔的物料減少，使收縮率增大；但物料溫度的升高會(huì)使粘度減小，卻有利于向型腔內(nèi)傳遞壓力，又使收縮率減小，終收縮率的大小取決于這上述兩種效應(yīng)的綜合影響。一般粘度對(duì)溫度變化敏感的塑料，后一種效應(yīng)影響大，致使收縮率減?。赫扯葘?duì)溫度變化不敏感的塑料，前一種效應(yīng)影響大，導(dǎo)致收縮率增大。

After another point is that increasing the pressure can lead to the increase of the density of the plastic self sealing bag and reduce the shrinkage rate. Increasing the material temperature will make the product volume expand and reduce the material pressing into the cavity, which will increase the shrinkage rate; however, the increase of material temperature will reduce the viscosity, which is conducive to transfer pressure to the cavity and reduce the shrinkage rate. The final shrinkage rate depends on the comprehensive influence of the above two effects. In general, the latter effect has a great influence on the shrinkage of plastics which is sensitive to temperature change, which leads to the decrease of shrinkage rate; for the plastics whose viscosity is not sensitive to temperature change, the former effect has a great influence, leading to the increase of shrinkage rate.

以上就是濟(jì)南自封袋的相關(guān)介紹，更多的相關(guān)知識(shí)請(qǐng)關(guān)注公司網(wǎng)站：http://www.673338.com.cn，我們會(huì)定期更新更多的相關(guān)知識(shí).。

The above is the introduction of Jinan self sealing bag. For more relevant knowledge, please pay attention to the company's website: http://www.673338.com.cn We will update more relevant knowledge regularly.