The cause of bag heat sealing strength bad?

About the bag making a few small problem, small make up will take you to understand one question now, the cause of bag heat sealing strength bad? When the bag heat sealing strength difference cause analysis. Heat sealing strength difference is most commonly occurs in the process of bag making problems. And the intensity of heat sealing poor generally affected by three aspects, to analyze in detail below. 1, when the bag heat sealing materials: the influence of different kinds of heat sealing material, heat sealing strength, such as PP, PE, EVA heat seal strength is inconsistent; The same film products of different polymerization methods, different heat sealing strength; The thickness of the material, uniformity, could also affect the heat sealing strength; Heat sealing layer of different processing methods, such as blow molding, cast film, etc. , influence the heat sealing strength. Film preservation time is too long, deposition, after corona treatment heat sealing strength is poor. Hygroscopic material moisture absorption, heat cover layer and peel strength decreased. 2, before the bag composite film processing technology: the influence of printing ink temperature resistance is poor or in ink additives not appropriate, under the high temperature of bag making, printing layer delaminating, heat sealing strength decreased. Heat sealing side should be designed without pattern. In composite process adhesive selection is very important also, the binder ratio, viscosity parameters such as the reasonable or not will affect the sealing strength. In composite extrusion or coating process, the processing temperature, material surface oxidation degree is big, carboxyl generation increases, heat sealing. 3, the influence of bag making process, the sealing side of cooling after hot sealing is not enough, finalize the design is insufficient, can't eliminate the internal stress, impact strength and appearance, should check in time, strengthen the cooling water circulation system. Heat sealing, the more the higher the heat sealing strength. Longitudinal heat sealing number depends on the longitudinal welding knife effective length and the ratio of the bag length; Lateral heat sealing number by the combination of the machine horizontal heat sealing device for decision. Good heat sealing for heat sealing number for at least two more times. Bag heat sealing strength bad cause analysis, in this way can help us to better solve the bag making, improve production!