Under normal circumstances, a batch of finished product packaging is not immediately used, and it is sometimes possible to stock for several months or even a year. Therefore, it is very important for an adhesive to have good cold and heat resistance and good aging resistance. For example, some packaging boxes work well for a short period of time, and after a period of time, degumming and film brittleness have occurred. Therefore, when determining the adhesive properties of a glue, the following aspects should be examined.
First, tear a spliced package along its edges to see if it is torn by the adhesive substrate and scrape the paper base attached to the film with a fingernail. If only a small piece can be removed at a time The paper base or simply cannot scratch the paper base, indicating that the adhesive has good adhesion on the film. Plastic/plastic sealing glue Because the two adhered surfaces are BOPP film, the film cannot be destroyed because of its strong flexibility, so it can be felt that the two adhered surfaces have strong adhesive force during inspection.
Second, put the bonded packaging box (at least one day has been placed) in a thermostatic oven at 60°C and bake it for 72 hours. After cooling, the seam or bottom does not pop open. Degumming, the film is not brittle, indicating that the heat resistance of the adhesive is no problem.
Third, the bonded packaging box (at least one day has been placed) in the refrigerator freezer frozen for 72 hours out, until the box is dry and hands to shoot the box does not degummed, the film is not brittle, indicating The adhesive has no problem with low temperature resistance.
Fourthly, save some samples of adhesive products adhered by the first three kinds of adhesives, check one box every two weeks, and do not take off the glue with both hands. The film is not brittle, and there is no problem in the continuous inspection for six months. Sealing glue can be used with confidence.
