Usage and Storage Precautions for Liquid Silicone Rubber
Liquid silicone rubber (LSR), as a high-performance elastomer, is widely used in various fields, including sports equipment, electronics, electrical appliances, and medical devices due to its excellent physical and chemical properties. However, to ensure optimal performance and extend the lifespan of LSR, proper usage and storage methods are crucial.
Usage Precautions for Liquid Silicone Rubber
Mixing Ratio and Blending
Liquid silicone rubber is typically available in one-component and two-component types. One-component LSR is easy to use and can be extruded directly, while two-component LSR requires strict measurement of each part according to the specified ratio, using an electronic scale to ensure accuracy. During mixing, a mixer should be used to thoroughly blend the components until no particulate matter remains.
Vacuum Defoaming
After mixing, the LSR needs to undergo vacuum defoaming to remove any trapped air bubbles. The container holding the silicone should not be filled to the brim to prevent overflow during the defoaming process. After defoaming, inspect the silicone to ensure no bubbles remain before proceeding to the next step.
Pouring and Curing
The defoamed LSR can then be poured or injected into molds. Before pouring, it is recommended to apply a detergent or mold release agent to the mold surface to facilitate easy demolding. The curing time varies depending on the type of LSR; generally, it takes 2 to 12 hours at room temperature, with some products capable of curing within minutes when heated (80-120°C).
Heat Curing (If Applicable)
For LSR that requires heat curing, the process should be carried out in a high-temperature oven or tunnel furnace. It is important to strictly control both temperature and time during heating to prevent the silicone from degrading or burning.
Machine Operation
To improve production efficiency, automated dispensing machines can be used for LSR processing. A dual-component dispensing machine requires precise mixing ratios for the two components, and machine operation must adhere to relevant safety protocols.
Storage Precautions for Liquid Silicone Rubber
Avoid Direct Sunlight
LSR is susceptible to UV damage, so it should be stored away from direct sunlight. Ideally, it should be kept in a cool, dry, and well-ventilated place to minimize UV exposure.
Sealed Storage
After use, LSR should be sealed promptly to prevent oxidation from air exposure. Specialized sealable bags or containers should be used, ensuring they are well-sealed.
Avoid Moisture Exposure
LSR is hygroscopic and can easily absorb moisture; hence, it should be kept away from water and humid environments during storage. Maintaining a dry storage environment will help prolong the life of the silicone.
Observe Shelf Life
The shelf life of LSR typically ranges from 6 months to 1 year. The quality of silicone will gradually deteriorate beyond its shelf life, losing its original properties. Therefore, the shelf life should be checked before use, and the silicone should be used within this period.
Regular Inspection
Containers holding LSR should be regularly inspected for damage or leaks. If any issues are detected, the containers should be replaced or other remedial actions should be taken promptly to prevent contamination or degradation of the silicone.
By following these precautions, the optimal performance and longevity of liquid silicone rubber can be ensured, thereby enhancing the quality and reliability of the final products.