There are a wide variety of protective films. Among them, ordinary protective films have a simple structure without functional layers and are mainly composed of a substrate and pressure-sensitive adhesives. PET, PE, OPP, PI, TPU, PVC and so on are common types of substrates, which are selected according to application scenarios and functional requirements. Pressure-sensitive adhesives can be divided into polyurethane (PU), acrylic and silicone types, each with its own unique physical and chemical properties. Silicone pressure-sensitive adhesives have become the first choice for electronic protective films due to their excellent resistance to high and low temperatures, weather resistance, good outgassing performance and light transmittance. When choosing silicone pressure-sensitive adhesives, adhesiveness is the primary consideration. It involves initial adhesion, holding power and cohesion, rather than a single peel strength. The substrate, adhesive coating thickness and formulation will also affect the adhesiveness. The characteristics of this series of products include similar viscosities, uniform mixing, stable adhesiveness, good coating appearance, long bath life, and support for low-temperature curing. When choosing pressure-sensitive adhesives, in addition to adhesiveness, application performance is also crucial: Shipping protection (such as polarizers): Protective films are required to have good die-cutting properties, less silicone transfer, no adhesive residue, and stable performance under damp-heat aging conditions. Even after aging for several days under high temperature and high humidity (85 °C / 85% RH), they can still perform stably, without backing delamination, have strong adhesion and excellent die-cutting performance. Process protection (such as evaporation coating, screen printing): Silicone pressure-sensitive adhesives are required to withstand special process conditions without affecting other components. For example, in the lens coating process, it needs to withstand temperatures as high as 200 °C, maintain adhesion and cohesion, not warp during the laminating process, have no adhesive residue after peeling, less silicone transfer, and not affect subsequent processing. Terminal protection (such as tempered glass films for mobile phones): The adhesives are required to have high transparency, good wettability and strong outgassing performance. Due to its excellent outgassing performance, it gives the protective film good adhesion, making it an ideal choice for protecting smart devices.