Before using the cup seal labels, it is necessary to test the type of adhesive, so that we can quickly understand whether this adhesive belongs to adhesive hot melt adhesive or adhesive water paper. Some adhesives will react with some substances, for example, the adhesive used as labels will contaminate special fabrics under certain conditions.
Some labels that require temporary tackiness produce long-term tackiness in an exposed environment. In addition, some labels will lose stickiness under certain circumstances.
There is a certain reason why the cup seal labels are not firm. Some customers think that this is a quality problem, but in fact, it is not a quality problem. Here are three methods for testing the adhesiveness of cup seal labels.
1. Initial adhesion: The common method is rolling ball method, which is to fix the adhesive face-up on an inclined plane and then slide steel balls of different sizes down from the top. The larger the steel balls that can adhere, the better the initial adhesion.
2. Sticky force: Stick the adhesive with two standard steel plates with hooks, then hang a steel plate on the fixing frame and put a 2kg weight on the other side to see how long the following steel plate can hold on and not fall off. The longer it lasts, the better the sticky force will be.
3. Peeling force: Stick the adhesive onto a standard steel plate, peel off the label at a constant speed with the instrument, and record the force used by the instrument. The force is the peeling force of the adhesive.