Coated paper is a composite material that coats plastic particles onto the surface of paper through a tape casting machine. Its main feature is that this composite material can be oil resistant, waterproof (relatively), and can be thermally sealed. The technical indicators of coated paper include the following: dry silicon coating amount, room temperature peeling force, aging peeling force, and residual adhesion rate.
Dry silicon coating amount refers to the amount of release agent applied to the material, in grams per square meter. Generally, the coating amount of solvent based silicone oil ranges from 0.30 to 0.80 grams per square meter, while the coating amount of solvent free silicone oil ranges from 0.80 to 1.30 grams per square meter. Professional testing equipment is required to test the coating amount. The amount of silicone oil coating directly affects the peeling performance.
A higher coating amount can densely cover the base paper, ensuring uniform distribution of silicone oil. However, with a lower amount of silicone oil coating, it is easy to experience phenomena such as missed coating, resulting in poor peeling. Some release coating suppliers reduce the amount of silicone oil coating, resulting in heavy peeling and producing heavy release paper, which poses considerable risks during use.
A reliable manufacturer adjusts the peeling force by adjusting the chemical formula without reducing the amount of silicone oil coating. This requires a considerable amount of technical accumulation, rather than being achieved overnight.
The peel force data obtained through standard testing methods at room temperature, in N/25mm, can be converted into several grams.
Generally, a peeling force of 0.10N/25mm, which is less than 10g, is commonly known as light peeling; 0.20N/25mm, which is the peeling force below 20g, commonly known as medium peeling; 0.35-0.45N/25mm, which is a stripping force of 35-45g, commonly known as heavy stripping; 0.60-0.80N/25mm, which is a peeling force of 60-80g, commonly known as heavy peeling; Of course, there is also a stripping force of 0.03-0.04N/25mm, which is 3-4 grams, commonly known as gentle stripping; There is also a stripping force of 1.00N/25mm, which is more than 100g, commonly known as overweight stripping.
The peel strength measured after aging is generally slightly higher than the peel strength at room temperature.
Residual adhesion rate refers to the force exerted on the release paper after the first peeling and the second peeling. The calculated data mainly reflects the curing effect of silicone oil. The residual adhesion rate of UV cured silicone oil is generally 100%, and the maximum residual adhesion rate of thermal cured silicone oil is 90%. If a few suppliers claim that their residual adhesion rate of release paper is 100%, it is suspicious.
If desilication occurs, the residual adhesion rate of this release paper will generally not exceed 70%. Testing the technical specifications of release paper is a quite complex project. Generally, electronic factories and tape factories can only test the last few data items. As for the amount of silicone oil coating, it generally does not appear in the technical reports of release coating suppliers.