Hardness is one of the important indicators for measuring the quality of silicone. Generally speaking, the higher the rubber content, the lower the hardness. The hardness of silicone mainly adopts the Shore hardness standard, and the tester also uses a Shore hardness tester. The hardness ranges from 0 to 100 degrees, and the use of hardness varies depending on the product's functionality. Silicone products have different hardness depending on the process, and there are two types of processes: liquid and solid.
1. The liquid silicone process can be used to produce "low-grade" silicone rubber products, such as 0 to 20 degrees, even if you have it on hand, it is still very viscous. This type of silicone product is usually rare, and developing a liquid silicone mold is particularly expensive. For a few people, it usually costs tens of thousands of dollars. Most liquid processes occur at around 10 to 20 degrees Celsius. For some silicone rubber products produced using liquid technology, silicone products made using liquid technology are not easy to self disassemble, and due to material reasons, the edges of the products may not be smooth. Therefore, the liquid process is suitable for low-grade silicone products and does not require very strict self-assembly.
Liquid silicone products recommendation: silicone nipple
2. Solid state process. Currently, the minimum softness of the solid silicone process is about 30 degrees, and the maximum softness is 80 degrees. Although it can reach a higher level, the failure rate is too high, and the product is very brittle and difficult to disassemble on its own. Therefore, the optimal soft hardness for solid-state processes is between 30 degrees and 70 degrees. Unable to produce softer products, but with good self removal edges, the product has a beautiful appearance and no burrs.
Generally speaking, the hardness of silicone rubber products is 30-80, which is also the common hardness of silicon gel and is applicable to most silicone products. Silicone products have good toughness and elasticity. Due to external forces that are not easily deformed, there will be a layer of oily substance, so the touch will be very smooth.
Regarding silicone rubber, please check the details:
https://www.siliconerubbers.net/product-common-grade-htv-silicone-rubber.html 
