Introduce some common core parameters of silicone rubber:

A. viscosity

The volumetric resistance to flow of a liquid, quasi-liquid or quasi-solid substance, that is, the internal friction or resistance between molecules when they flow under the action of an external force. Usually viscosity is proportional to hardness.

B. Tensile strength

Tensile strength is the force per unit range required to tear a sample of rubber material. The range of tensile strength of hot sulfur-added solid silicone rubber is 4.0-12.5mpa. Fluorosilicone rubber tensile strength range between 8.7-12.1MPa. The tensile strength of liquid silicone rubber ranges from 3.6-11.0mpa.

C. hardness

The local resistance of a material to hard material pressing into its surface is called hardness. Silicone rubber has a Shore hardness range of 10 to 80, which gives the designer full freedom to choose the required hardness to best achieve a particular function. A variety of intermediate hardness values can be achieved by mixing polymer substrates, fillers and auxiliaries in different proportions. Similarly, the time and temperature of heating and curing can also change hardness without destroying other physical characteristics.

D. Tear strength

Resistance to the expansion of incisions or nicks when force is applied to incised samples. Even after cutting and placed under extremely high torsional stress, hot sulfur solid silicone rubber can not be torn. The tearing strength range of hot sulfur solid silicone rubber is between 9-55 kN/m. Fluorosilicone rubber tear strength range between 17.5-46.4kN /m. Liquid silicone rubber tear strength range between 11.5-52 kN/m.

E. Operation time

Operation time is calculated from the moment the gel is added to the vulcanizer. This operation time and the curing time behind the fact that there is no complete boundary, the colloid from the moment of adding the curing agent has been curing reaction, this operation time is that the product 30 minutes of curing reaction can not affect the quality of the finished product. Therefore, the more time saved during the operation of the product, the better for the finished product.

F. Proportion of vulcanizing agent

Silicone rubber is the most common two-component vulcanized silicone rubber. When it is not used, silicone rubber is divided into colloidal and vulcanizing agent. When it is used, it can be operated after being mixed evenly in a certain proportion. In general, only the weight of colloid needs to be considered, and in special cases, the weight of other additives of silica gel needs to be considered. For example, the proportion of vulcanizing agent used by pad printing silica gel needs to be calculated according to the total weight of silica gel and added silicone oil.

G. elongation

This is usually referred to as the "ultimate elongation at rupture" or the percentage increase in the original length of the sample when it breaks. Thermal sulfurized solid silicone rubber generally has a range of elongation between 90 and 1120%. Fluorosilicone rubber generally has a elongation between 159 and 699%. Liquid silicone rubber generally has a elongation between 220 and 900%. Different processing methods and selection of hardening agent can greatly change the elongation. The elongation of silicone rubber is closely related to temperature.

H. Curing time

Some places will say curing time. In other words, after such a long time, the vulcanization of silica gel is basically over. So this is basically finished which means that the product is ready to use, but in fact there is still a very small fraction of the curing reaction that is not finished. So products made of silicone rubber, such as silicone moulds, usually have to sit for a period of time before they are put into use.