The layer of white paper on double-sided tape is called release paper, also known as silicone oil paper or anti-stick paper. Its core function is to prevent the tape from self-sticking when it is rolled up for storage, and at the same time ensure that it can be easily peeled off when in use.
The design of release paper is very ingenious. First, a certain material must be selected as the release substrate. As for what material to choose, it also depends on the specific application environment. Siliconized paper is a commonly used release substrate material. If die-cutting capability is required, polyester material is the first choice. If it needs to be exposed to a humid environment, choosing polyethylene coated paper would be better because it has dimensional stability.
After the general substrate material is determined, the release agent cannot be directly applied because the release agent has a certain degree of permeability. If there is no barrier, it will penetrate into the interior of the paper, resulting in poor curing and excessive use of the release agent. Therefore, it is necessary to first carry out plastic coating treatment on the substrate (commonly known as lamination). However, some release papers do not undergo plastic coating treatment, such as glassine and CCK, etc. Instead, they adopt other special processing methods.
Subsequently, a release agent will be applied, which will significantly reduce the surface energy and ensure that the tape can be torn. Release agents are mainly composed of wax and silicone resin. They remain solid at room temperature and have viscosity, but melt at a certain temperature (around 150℃). The release agents are mainly organosilicon release agents, with organofluorine release agents and some other non-silicon release agents as supplements. In addition, the release force on both sides of the tape is different, which is why the tape always adheres to the side of the release paper when in use.