Drop test of composite membrane packaging bag

Today I want to share with you the topic of drop test of composite film packaging bags.
Regarding the drop performance of composite film bags, the relevant regulations are as follows:
Total mass of packaging bag and contents (g) Drop height (mm) Requirements
<100 800 The packaging bag is not broken
100~400 500 The packaging bag is not broken
>400 300 The packaging bag is not broken
The test method is: the test surface is a smooth, hard horizontal surface (such as a cement floor). The packaging bag is filled with actual contents or about half of the capacity of water, and the number of samples is 5. According to the above table, the packaging bag is dropped freely once in the horizontal direction and the vertical direction, and visually inspected for rupture.
In actual applications, Ancopack’s drop test conditions are usually much higher than the specified requirements, ensuring the quality of the delivered products and enhancing the company’s good quality reputation.
In the drop test, there are three possible locations where the composite film bag breaks: one is on the seal of the composite film bag, that is, separation occurs between the heat-sealed layers at the seal; the second is that “root cutting” occurs at the inner edge of the seal of the composite film bag; the third is that the composite film breaks at the bag body (non-seal). No matter which bag breaking phenomenon occurs, it means that the impact force generated by the contents in the drop test is greater than the corresponding technical indicators of the composite film bag, such as tensile fracture stress or heat sealing strength.
We have the following methods to improve the drop performance of composite film bags:
1. When purchasing raw materials, choose substrates with higher tensile fracture stress;
2. When purchasing raw materials, choose substrates with larger nominal fracture strain;
3. When purchasing raw materials, choose substrates with smaller tensile elastic modulus;
4. Adjust the bag-making process conditions to eliminate or reduce the degree or possibility of “root cutting” of the composite film at the seal;
5. Change the bag shape and seal design to disperse the impact force.
The above-mentioned “substrate with larger nominal strain at break” refers to non-heat-sealable substrates, i.e., the substrates of the surface layer and the middle layer of the composite film. The result of this is that the softness of the composite film increases and the stiffness decreases. In the drop test, the impact force generated by the contents will be more attracted by the elastic deformation of the composite film, thereby greatly reducing the incidence of bag breakage.
The nominal strain index of the composite film at break is not less than 100% under the application environment temperature conditions.