How to control the hardness of silica gel?


2020/12/9 18:48:38



Silicone rubber and plastic products have different requirements on the hardness of rubber and plastic products in different occasions and different use environments. For example, silicone breast implants have lower hardness in order to achieve a true feeling with the chest. What is the hardness of all kinds of silicone products? What is the difference between the hardness of silica gel and what is the hardness standard of silica gel?


Ordinary products with large or soft hand feel can be directly measured by Shaw HA hardness tester, such as stationery plastic bottles, TPU, TPR plastic film bags and other products. Moreover, those who feel basically inelastic or hard can be tested with Shaw HD hardness tester, such as PC, ABS, PP and other products. If the content is Shaw xxHA, the hardness is lower, and if the content is Shaw xxHD, the hardness is higher. Silica gel products with different hardness are selected for use in different fields. The conventional low hardness can reach about 10 degrees, and even lower is 3-5 degrees. The conventional hardness of commonly used silica gel products ranges from 30 to 70 degrees. It is also the reference hardness of most products, but the hardness of silicone products made of special materials can reach about 80-95 degrees.


The other is the common silica gel processing technology, that is, the processing technology of solid silica gel products. At present, the processing technology of solid silica gel products in the whole silica gel industry can achieve the lowest softness of 10 degrees and the highest hardness of 90 degrees, although the highest can be achieved, but the defective rate is too high, the products are brittle, the cost is high, and it is difficult to demould. Therefore, the most suitable hardness of solid technology is between 30 and 70 degrees. The tear resistance of silica gel changes. The higher the hardness, the weaker the tear resistance, especially the products with right angles are prone to tear fracture. The lower the hardness, the better the tear effect. Different hardness has different tear effects. Of course, it also depends on the gel content of the product. The scalability and related properties of silica gel with different gel content are also very different. Deformation caused by a certain expansion force, which is an important control index of silicone materials, is related to hardness. Different hardness and temperature and pressure during vulcanization have great influence on tensile deformation of silicone materials. Wear resistance and fatigue degree change, and products with different hardness have different effects on wear resistance and fatigue degree. The hardness of ordinary silica gel materials increases with the increase of white carbon black content, and fatigue degree decreases after long-term running-in.


Elasticity is one of the important properties of silicone materials. Therefore, materials with different hardness have an impact on different application products, and the difference in hardness changes is too great, which may lead to the use effect of the whole product and even affect every link of the whole product!

Therefore, many customers failed to correctly explain the hardness when purchasing silicone products, and did not specify the hardness requirements of materials. However, the hardness selection of silicone products can directly affect the use effect of your whole products. Friends who do not know the hardness of silicone materials can know the hardness of silicone materials before deciding the hardness.






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