Silicone rubber and metal bonding process

With the continuous innovation and advancement of silicone industry technology, silicone rubber is used more and more widely in life. However, sometimes we encounter some problems in application, such as how to bond silicone rubber products to metal.

1. Metal surface treatment. To achieve adhesion, the metal surface must be treated first. Commonly used methods are: chemical, mechanical and solvent. Generally, silicone product factories select methods based on actual conditions. Mechanical treatment often uses sandblasting. , grinding with emery cloth or grinding wheel, etc., especially sandblasting method, which is low cost, fast and effective, and has been widely used. Chemical treatment is also commonly used, especially the anodizing treatment of aluminum and its alloys, and the copper plating treatment of steel, which requires chemical methods. The treated metal surface should be promptly coated with adhesive, silicone rubber or immersed in an inert solvent.

2. The design of metal joints (recommended product: fluororubber joints), in order to achieve the bonding of silicone rubber and metal, starts with the bonded joints. Because it is part of the overall design of the product, let’s first understand the design principles of joints:

Fluorine rubber joint

1) Enlarge the bonding area as much as possible and improve the bearing capacity of the bonded joint;

2) The stress mode of the bonded joint should be shear force or tensile force to prevent peeling force;

3) The bonding length in the direction of stress should not be too long, and the bonding width should be increased as much as possible;

4) The stress direction of laminate bonding should avoid layer separation;

5) Bevel bonding is better than right angle bonding;

6) Joints subject to lateral stress should be bonded by die surface. Based on the above principles and the characteristics of rubber products, methods such as drilling holes in metal parts and turning thread grooves are generally used to improve the bonding strength of joints.