Pearlescent film bubble bags are widely used in cold drink industry, and delamination is essentially the manifestation of peeling (composite) strength problems. The problems are mainly caused by the following aspects:
1) The surface tension of pearlescent film materials or printing materials is low, which does not meet the printing or composite requirements.
2) Improper drying temperature control or use of many solvent residues affect the peel strength.
3) Printing ink and printing substrate are not compatible, the compatibility is not good.
4) Improper temperature control of compound oven has a serious impact on solvent evaporation.
5） 复合辊温度偏低 ：进步复合辊温度。其实复合辊温度的凹凸，应该与机速、资料的厚薄有很大的联系，还与胶水的性质有联系。
5) Low temperature of composite roller: improve the temperature of composite roller. In fact, the concave convex temperature of the composite roller should be closely related to the machine speed, the thickness of the data, and the nature of the glue.
6) Problems in aging time or temperature control.
At that time, there were some misunderstandings in the detection of peel strength between developing layers and layers: only the peel strength of non heat sealing area was detected, while the detection of composite strength of heat sealing area was ignored. However, delamination often occurs in the heat sealing area. Therefore, in order to ensure the quality, it is necessary to test the non heat sealing area and the heat sealing area respectively, and only when all of them reach the index requirements can they be judged as qualified.
In order to facilitate enterprises to understand peel strength testing, several details in the testing process are summarized for reference:
1) Specification reference: comply with GB 8808 "soft composite plastic data peel test method".
2）制备试样注意事项： 一定要将样品宽度方向的两头除掉50 mm之后再取样（如有条件），取样后将试样预剥开不要当即忙于试验，而是先要检测被剥开部分应当无损伤方可；若试样不易剥开时可用溶剂处理，但要注意试验一定要在溶剂完全蒸发后进行，并且一定要适当增加预剥开区域的长度，以免测试结果受到溶剂的影响。
2) Precautions for sample preparation: be sure to remove both ends of the sample width direction by 50 Mm and then take the sample (if possible). After taking the sample, pre peel the sample not to be busy with the test immediately, but to detect that the peeled part should be free of damage; if the sample is not easy to peel, it can be treated with solvent, but it should be noted that the test must be carried out after the solvent has completely evaporated, and the length of pre peel area must be increased appropriately to avoid the influence of solvent on the test results.
3) Test speed: there are two speeds of a and B in the specification, but now the test speed of 300 mm / min of a method is widely performed.
4) Precautions for specimen clamping: after the specimen is clamped on the upper and lower (or left and right) chucks of the testing machine, the longitudinal center line of the specimen shall coincide with the center line of the upper and lower chucks.
5) Selection of testing machine: the peel strength of packaging materials is different from the process data processing mode of peel strength of other professions. In order to ensure the accuracy of data, it is necessary to select a special tensile testing machine for packaging profession, otherwise the data will be different.