Industrial Adhesive Tapes
● What are Industrial Adhesive Tapes?
- We introduce the structure of adhesive tapes, the mechanism of "sticking", and the difference between "adhesive" and "PSA (pressure sensitive adhesive)".
● Structure of adhesive tapes
- Adhesive tapes are composed of carriers, pressure sensitive adhesives(PSAs) and separators.
There are roughly divided into two types: double-coated and single-coated.
Various functional adhesive tapes are being developed by selecting constituent materials successfully.
▶ The mechanism of “sticking” :
- One of the sticking mechanism between adhesive tapes and objects is ”intermolecular force”.
This is an electrical interaction occurring when two molecules come into close proximity with each other.
Generally, two objects don’t stick together however close they are.
The reason is that the surfaces of objects are rough at the nano level and molecules can not approach each other until the intermolecular force works. For filling the unevenness of both object’s surface and allowing them to stick together, we can use “PSAs".
The fluidity of PSAs fill the objects surface unevenness, resulting in the occurring intermolecular force that stick objects together.
▶ Difference between “adhesive” and “PSA(pressure sensitive adhesive)”
- The most common material used to stick objects together is “adhesive”.
Actually, PSA is a type of adhesive, which can stick objects when pressure is applied to.
- Compared with adhesive, a major feature of PSA is absence of state change before or after bonding(pressing) to objects.
As three states of matter, there are solids, liquids and gases. PSA always has both liquid and solid characteristics.
On the other hand, adhesive is changing its state from liquid to solid through curing process.
Liquid before curing
Solid after curing
No state change before or after bonding;
Always has the both characteristics liquid and solid
- Compared with adhesive, the advantages of adhesive tape using PSA are “immediate adhesion”, “can be converted to any shape”, and “uniform thickness”. Because of these advantages, adhesive tape is highly convenient and is used in a wide range of applications.
On the other hand, the one of disadvantage is weaker adhesive force than adhesive.
▶ Characteristics of adhesive tapes compared with adhesives
- Immediate adhesion via pressing
- Can be converted to any shape(e.g. by die-cutting)
- Uniform thickness
Weaker adhesive force