The coating amount of adhesive is an important indicator that determines the performance of self-adhesive materials. The generally recommended coating amount is 22g/m2 with a tolerance of ±3g/m². The coating amount of adhesive can vary according to different seasons and different regional temperature and humidity, and can also be increased or decreased according to customer requirements and special uses.
Generally speaking, the coating amount is larger in winter than in summer, and the coating amount in the north should be larger than that in the south in winter. For different substrate surfaces, the coating amount of rough surfaces is larger than that of smooth surfaces. The coating amount is also related to the adhesion of self-adhesive materials. Within a certain range, the adhesion is proportional to the coating amount, but there are certain limitations. The coating amount has a direct impact on the processing, storage and application of materials.
The coating amount is too large.
1. Glue seepage will occur, especially in summer, the ends of the rolls will stick together or single sheets of paper will stick together, resulting in waste and bringing difficulties to storage.
2. Difficulty in slitting reels and sheets. The blade is easy to stick to the paper surface or end surface, which brings hidden dangers to the printing process.
3. Difficulty in feeding paper on the printing machine. The end surface of a single paper must be powdered. Adhesives often stick to the paperboard, affecting normal paper feeding and positioning.
4. After a label with too much glue is attached to the product, the surrounding area of the label will seep glue, and dust will form a black edge, affecting the appearance. In addition, when the temperature is high, the label will move and dislocate on the product.
Too small coating amount.
1. Affects viscosity, making the label easy to fall off the product, especially on rough surfaces or curved surfaces.
2. Affects the material structure, that is, the release force between the surface material and the base paper is too small to cause the material to delaminate, or the label is peeled off together with the waste paper edge during die-cutting and waste discharge, and normal production cannot be achieved.
However, some customers require a small coating amount to achieve the effect of reducing viscosity, such as the labels used in some supermarkets. On the contrary, some customers require a large coating amount to increase the viscosity, such as sticking to special surfaces such as rubber tires. In short, Sinopack Industry can customize the corresponding label materials according to the application of different labels.