Jinan self sealing bag is made of polyethylene (LDPE) and high-pressure linear polyethylene (LLDPE) by blowing film and hot cutting machine-made bag, which can be repeatedly sealed. The self sealing bag can be used for the inner and outer packing of various small articles. The self sealed bags made of food grade raw materials can store all kinds of small food, tea, seafood, etc., which are moisture-proof, waterproof, insect proof and prevent things from scattering.

济南自封袋热封后袋子出现翘曲的原因可能是复合膜的厚度不一致，热封温度过高或热封时间过长，在纵向热封刀部分，复合膜的运行轨迹不平直。或者冷却与熟化时间不够充分，表层基材薄膜耐热性较差。复合过程中复合基材的张力匹配控制不当，导致济南自封袋熟化定型后仍有残余的应力，尤其是复合膜厚度较薄时更容易发生此类故障。

The reason for the warpage of Jinan self sealing bag after heat sealing may be that the thickness of the composite film is not consistent, the heat sealing temperature is too high or the heat sealing time is too long, and the running track of the composite film is not straight in the longitudinal heat sealing knife part. Or the cooling and aging time is not enough, and the heat resistance of the surface substrate film is poor. In the process of compounding, the tension matching control of the composite substrate is improper, which leads to the residual stress of Jinan self sealing bag after curing, especially when the thickness of composite film is thin.

要解决济南自封袋翘曲的办法也有很多。可以调整浮动辊张力，选用具有低温热封性的内封基材，将热封温度调整适宜的温度。要充分冷却和熟化。重新选择自封袋表层基材薄膜，调整复合加工设备各部分的张力，尽量使相复合的两种基材回缩率相等。

There are many ways to solve the warpage of self sealing bags in Jinan. The tension of floating roller can be adjusted, and the inner sealing base material with low temperature heat sealing property can be selected to adjust the heat sealing temperature to the appropriate temperature. Cooling and ripening should be sufficient. Re select the substrate film on the surface of the self sealing bag, adjust the tension of each part of the composite processing equipment, and try to make the shrinkage ratio of the two composite substrates equal.