Do You Really Know Adhesives?

Posted by Kuajing Plus on December 16th, 2022

In China, pasting Spring Festival couplets at Chinese Spring Festival is a kind of cultural inheritance and a good wish for health and happiness in the coming year. Most people will take the wishing contents or good-looking patterns of Spring Festival couplets into consideration before buying. When they want to replace Spring Festival couplets, they find last year’s couplets are very difficult to tear off; or left ugly glue residue on the door. To get rid of glue residue, they have tried using alcohol to wipe or using hair dryers to heat. But it is in vain. Not only wasting a lot of time but also spoiling the surface of the door. If Spring Festival couplets manufacturers would think more for customers, their products will certainly stand out and be favored by customers.

For most people, the adhesive should be easy to stick. More sticky, the better. While in some product areas, the adhesives should not only be “easy to stick”, but also be “easy to tear” and free of glue residue.

Different surfaces have different “skins” and we should choose proper adhesives according to different “skins”. The wrong use of adhesives will be a disaster.

What is water-based pressure-sensitive adhesive?

There are many kinds of adhesives, the most common product in our daily life is pressure-sensitive adhesives, which are widely used for carton seal tape, double-sided tape, labels, washi tape and etc.

Pressure-sensitive adhesive ( also known as PSA, self-adhesive, or self-stick adhesive) is a type of nonreactive adhesive which forms a bond when pressure is applied to bond the adhesive with a surface. There are four types of pressure-sensitive adhesives: solvent-based PSAS, emulsion or water-based PSAS, hot-melt PSAS, and radiation-curing PSAs.

Water-based pressure-sensitive adhesive is a kind of adhesive, which use deionized water as the carrier of pressure sensitivity. In recent years, with the expansion of the demand for packaging, decoration, and office supplies, the demand for pressure-sensitive adhesives is also increasing. With the advantages of its non-toxic, non-pollution, and brilliant performance on aging resistance and weather resistance, water-based pressure-sensitive adhesives are widely used.

Three key forces of adhesives

There are 3 forces of adhesive on the physical level: adhesive force (force between glue and base material), cohesion force (force between glue and glue molecules), and peeling force (force between the glue and attached surface).

adhesive force

Adhesive force is not only related to the properties of the water-based pressure-sensitive adhesive itself, but also to the tension force of the base material. If the tension force reaches 38 or 42 dyne value above, the lower the glue dyne value is, the better the adhesive force is on the basis of better affinity with the base material.

cohesion force

It is the force between glue and glue molecules, which can be adjusted through internal and external cross-linking agents to form a good network structure. The narrower and tighter the network distribution is, the greater the cohesion force is. The usage and dosage of cross-linking agents should be very careful, improper use will affect other mechanical properties of the adhesive. The internal crosslinking agent has finished the reaction in the process of formula polymerization, so the properties of the finished glue can not be modified. Most adhesives adopt a two-components structure. By adding the external cross-linking agents, the cohesion force could be adjusted, and get a better relationship between the three forces.

Peeling force

The peeling force is the force most directly related to the coated surface (“skin”), and it is also the first force that should be confirmed according to the different “skin” of many adhesive products. The smooth surface needs a lower peeling force, while the rough surface requires a higher peeling force. The corresponding adhesive formula could be designed according to the ideal three-forces relationship and the confirmed peeling force.

Why was the adhesive transferred?

Before handling the problem of glue transfer, we should understand why the glue will transfer.

The ideal relationship of the three forces is adhesive force > cohesion > peeling force. When the three forces reach this state, it is not easy to transfer glue or leave glue residue. In contrast, if the balance is broken, the adhesive transfer will occur.

Water-based pressure-sensitive adhesive Manufacturer, you can Trust

Our aim is to supply one-stop services and proper product solutions for our customers. We set up a subsidiary company in Anhui Province to specialize in the production of water-based adhesives. It could not only meet the needs of our own product but also sell to other companies. Through nearly 30 years of development, we have earned rich experience in supplying protective films and water-based adhesives. We have experience and confidence in serving global customers. Contact us if you would like to know more.