Self-adhesive label is the most widely used label at present, but its structure is not simple. Typical adhesive labels consist of five layers, including:
The first layer, appearance data, or raw materials, is used to record or print graphic information.
The second layer, primer, or tackifier coating, enables a closer separation of adhesives and appearance data. Primer also has the effect of avoiding chemical reagent immersion, otherwise the chemical reagent may be immersed from the bottom three layers to dirty the label appearance. In addition, color primers can also be used as backgrounds for transparent appearance data.
Layer 3 - Adhesive for labels. Before tearing off the outer lining of the label and pasting the label on the surface of an object, the adhesive keeps the appearance information away from the silicone-coated lining.
The fourth layer, silicone coating, is used to ensure that labels and linings are easily separated.
Layer 5 - Paper lining, which maintains that the label is not dirty before use, is usually made of bleached or pristine Kraft paper (occasionally clean polyester material). Paper lining also serves as a support to ensure that the label does not bend or curl in the process of handling the label.
Although the non-sticker label is widely used and welcomed by everyone, it can not be applied in any environment. For example, in frozen food packaging and other high-speed operations, the use of heat-sealed labels is more efficient and economical.
Importance of Viscosity Testing
It is important to test the type of adhesives for different types of non-drying labels before they are used. See if the adhesives belong to non-drying adhesives, heat sealants or glued paper. Some adhesives react chemically with specific substances. For example, non-drying glue labels used as labels can contaminate certain special fabrics under certain conditions. Some labels that require temporary stickiness produce durable stickiness under exposure conditions. On the other hand, some labels with durable stickiness will lose stickiness in some appearances.
Problems often arise when self-adhesive labels and other labels are used on the surface of recycled paper. There are many different kinds of paper in the process of stopping recycling. Some paper will be contaminated by the coating of silicon or wax, so the mixed processing will contaminate the final consumer goods. Adhesives are often ineffective when labeling the appearance of contaminated recycled paper. Note: The role of silicone coatings in sticker labels is to ensure that the sticker is easily detached from the lining.
Low temperatures can also cause problems. Low temperatures reduce the speed of bonding, and the label may have peeled off the surface before the adhesive adheres to the surface. If the label is stored improperly --- the ambient temperature difference is large, the humidity is shaken, or the stacking is improper --- the label will lose its stickiness soon after it is used.
One of the most important factors in the effective use of sticker labels is to peel the sticker from the outside of the lining paper correctly.
Many people mistakenly pull the label from the left or right corner, which will weaken the stickiness of contact with local adhesive, but also destroy the "external fibers" in the data, making the label curl.
The correct way to tear off the sticker label from the outside of the liner is to stick to the straightness of the label as far as possible and peel the liner from the center of the top or bottom to ensure that the label sticks well to the outside of the object.