在生產(chǎn)自封袋的過程中，一些工序會對自封袋的收縮率造成影響，在加工生產(chǎn)中要特別注意，避免生產(chǎn)出來的自封袋不合格，下面為大家講解幾種常見的影響自封袋收縮率的因素。

In the process of producing self sealing bags, some processes will affect the shrinkage rate of self sealing bags. Special attention should be paid to avoid unqualified self sealing bags produced in the processing and production. The following will explain several common factors affecting the shrinkage rate of self sealing bags.

1、自封袋自身結(jié)構(gòu)的影響：

1. The influence of self sealing bag structure was as follows

同一自封袋中，壁厚較小的部位的收縮率要小于壁厚較大的部位，遠離嵌件部位的收縮率要大于靠近嵌件部位的收縮率，垂直于流動方向與流動方向的收縮率也是有差別的，一般情況下流動方向收縮率大于垂直于流動方向的收縮率，自封袋受到阻礙方向的收縮率要比無阻礙方向的收縮率要小。

In the same self sealing bag, the shrinkage rate of the part with smaller wall thickness is smaller than that of the part with larger wall thickness, the shrinkage rate of the part far away from the insert is greater than that near the insert, and the shrinkage rate perpendicular to the flow direction is also different. Generally speaking, the shrinkage rate of the flowing direction is greater than that perpendicular to the flow direction, and the shrinkage rate of the self sealing bag in the obstructed direction is higher than that in the blocking direction It is smaller than the shrinkage in the unimpeded direction.

2、原材料對自封袋收縮率的影響：

2. The effect of raw materials on the shrinkage of self sealing bag is as follows

用不同原材料生產(chǎn)的自封袋的收縮率也是不同的，但是使用相同材質(zhì)生產(chǎn)的不同批次的自封袋收縮率也不相同，這主要是受到了加工生產(chǎn)過程的影響，結(jié)晶型的塑料的收縮率要大于無定形的塑料，流動性差的塑料成型收縮率大，流動性好的塑料成型收縮率小，如果在塑料中加入填充料會導(dǎo)致成型的塑料收縮率明顯下降，不添加填充物的塑料生產(chǎn)成型后的收縮率更好。

The shrinkage rate of self sealing bags produced with different raw materials is also different, but the shrinkage rate of self sealing bags produced with the same material in different batches is also different, which is mainly affected by the processing and production process. The shrinkage rate of crystalline plastics is larger than that of amorphous plastics. The shrinkage rate of molding of plastics with poor fluidity is large, and the shrinkage rate of molding of plastics with good fluidity is small Adding fillers into plastics will lead to a significant decrease in the shrinkage of plastics, and the shrinkage of plastics without fillers will be better.

3、壓力和溫度對自封袋收縮率的影響：

3. Effect of pressure and temperature on shrinkage of self sealing bag:

壓力過高會使得自封袋的密封增加，導(dǎo)致收縮率減小，如果提升生產(chǎn)自封袋的原材料的溫度，會使得自封袋的體積膨脹，通過壓力入型的物料變少，使得收縮率增大，但是原材料的溫度升高會使得粘度變下，粘度變小會使得型腔內(nèi)的壓力增多，使得自封袋額收縮率減小，所以終會影響自封袋的收縮率的因素取決于壓力和原材料溫度兩者的綜合影響。

Too high pressure will increase the sealing of the self sealing bag and reduce the shrinkage rate. If the temperature of the raw materials for the production of the self sealing bag is increased, the volume of the self sealing bag will expand, and the amount of the material fed through the pressure will be reduced, and the shrinkage rate will be increased. However, the increase of the temperature of the raw material will cause the viscosity to decrease, and the pressure in the cavity will be reduced, which will increase the shrinkage rate of the self sealing bag Therefore, the factors that will eventually affect the shrinkage rate of self sealing bags depend on the combined effects of pressure and raw material temperature.