The tensile strength, elongation and other indicators of composite packaging bag materials are extremely important for film suppliers and users. The experimental method for testing tear strength is to measure the force required to tear the bag. The main measurement method is trousers. method and Ellemendorf tear method, preferably the constant radius sample Ellemendorf tear method. For film processors, too much or too little tear strength is detrimental to the processing process. For consumers, the tear resistance of materials is a primary goal related to whether the packaging is easy to open.

The friction force in the actual packaging process is often both a drag force and a resistance force, so something must be used to effectively control the friction coefficient to keep it within an appropriate range. Coil materials for automatic packaging generally require a relatively small friction coefficient of the inner layer and a moderate friction coefficient of the outer layer. The uniformity of material thickness also has a major impact on the various functional goals of the material.

Heat sealing bag making is the last order of the whole composite packaging process. Heat-sealing bag-making requires superior heat-sealing strength, which can ensure that the subsequent processing of the composite bag will not leak. The tightness of the seal has a lot to do with the accurate selection of heat-sealing materials, heat-sealing pressure, heat-sealing temperature and time, and heat-sealing methods. Abrasion resistance, adhesion, printing accuracy and other objectives are mainly proposed according to the characteristics of the printing industry.

For inner composite packaging or small packaging bags, the sealing tester can be used to test the sealing function of the package after a series of simulation tests (such as shaking test, drop test, pressure test, etc.).