Food-grade silicone key chain waterproof sealing process

To achieve a waterproof sealing process for food-grade silicone key chains, it is necessary to start from aspects such as material properties, process design, and production operation. The following is a detailed introduction:

Utilization of material properties

Food-grade silicone itself has good waterproof performance. Its molecular structure is compact and can effectively prevent water penetration. During the production process, it is necessary to ensure that the silicone material used meets food-grade standards, contains no harmful substances, and has good elasticity and flexibility, so that it can still maintain a sealing effect when the key chain is squeezed or stretched.

Process design

Sealing structure: When designing the sealing structure of a key chain, it is advisable to consider using a combination of grooves and protrusions. For instance, a groove is designed on the main part of the key chain, and a matching protrusion is designed on the component that needs to be sealed. The protrusion is embedded in the groove, and the sealing is achieved through the elasticity of the silicone. This structure is simple and effective, and can effectively prevent moisture from entering the interior of the key chain.

Sealing interface treatment: For the interface parts on the key chain, such as the connection between the key chain and the main body of the key chain, sealing can be achieved by hot-pressing welding or adhesive bonding. Hot-press welding is a process that uses high temperature and pressure to melt and fuse silicone materials together, forming a solid seal. For adhesive bonding, a special adhesive suitable for food-grade silicone is selected to firmly bond the interface part. During the operation process, it is necessary to ensure the quality of welding or bonding to avoid the appearance of gaps or bubbles.

Production operation

Mold precision: The precision of the mold directly affects the size and shape of the key chain, and thereby influences the sealing effect. When making molds, it is necessary to ensure the dimensional accuracy and surface finish of the molds to enable the components of the produced key chain to fit tightly. For instance, the dimensional tolerance of the mold should be controlled within a relatively small range, and the surface roughness should meet certain standards to ensure the dimensional stability and sealing performance of the silicone after molding.

Molding process control: During the silicone rubber molding process, parameters such as temperature, pressure and time must be strictly controlled. Excessively high or low temperatures, insufficient pressure or inadequate time can all lead to poor silicone molding and affect the sealing effect. For instance, during the compression molding process, the molding temperature, pressure and holding time should be reasonably set according to the characteristics of the silicone and the requirements of the product to ensure that the silicone is fully cured and forms a dense structure.

Post-processing: The formed key chain may have some burrs or flaws and requires post-processing. Burrs can be removed by trimming, grinding and other methods to make the surface of the key chain smooth and flat. At the same time, the key chain should be cleaned to remove oil stains and impurities on the surface to ensure the hygiene and safety of the product.