4 Steps to Choosing Silicone Adhesive

Silicone adhesives are a category of bonding agents used to join silicone to silicone or silicone to similar plastics. They are widely used in applications involving plastics, electroplated components, wood, stone, glass, nylon, leather, and more. Kanglibang outlines the four steps for selecting the right silicone adhesive below:
1. Before selecting an adhesive, identify the specific materials to be bonded—such as silicone or silicone rubber—and determine whether the silicone is already molded or if it is being bonded to other materials like metal or plastic.
2. Next, determine the size of the bonding surface. For small areas, instant adhesives (cyanoacrylates) can be used; they offer strong bonding strength capable of achieving "substrate failure" (where the material itself tears before the bond breaks). For larger bonding areas exceeding 10 cm², a single-component, slow-curing adhesive is preferred. This provides sufficient working time and significantly lower costs compared to instant adhesives. While the bond may not achieve substrate-level failure, the tensile strength remains excellent.
3. Define the bonding requirements, such as bonding speed, adhesive color, viscosity, temperature resistance (high/low), and bond strength.
4. (1) Slow-curing adhesive (room-temperature bonding): Once cured, the bond remains soft, elastic, waterproof, and resistant to high temperatures, acids, alkalis, and tensile stress—mirroring the properties of the silicone itself.
    (2) Fast-curing adhesive (room-temperature bonding): When bonding silicone to silicone, a primer (treatment agent) must be applied to the bonding surfaces. Allow the treated surfaces to air-dry for about one minute before applying the adhesive and joining the parts. The bonded product must sit for 24 hours before undergoing high/low-temperature or tensile testing. This type of adhesive cures quickly and boosts production efficiency but is suitable only for bonding small-area products.
(3) High-temperature adhesive: After application, the parts must be baked in an oven at 80–90°C for approximately one hour. The resulting bond is soft, elastic, waterproof, and resistant to high temperatures, acids, and alkalis.