Influencing factors of liquid silicone products

I. Viscosity

Explanation of technical terms: the volumetric properties of liquids, quasi-liquid or quasi-solid substances that resist flow, that is, internal friction or internal resistance between molecules when flowing under the action of external forces Normally viscosity and hardness are directly proportional.

Second, hardess

The ability of a material to locally resist the intrusion of hard objects into its surface is called hardness. Silicone rubber has a Shore hardness range of 0 to 80, which gives designers full freedom to choose the hardness required to best achieve a specific function. Mixing polymer substrates, fillers and auxiliaries in different proportions can achieve various intermediate hardness values. Similarly, the time and temperature of heat curing can also change the hardness without destroying other physical characteristics.

Third, tensile strength

Tensile strength is the force required to cause a piece of rubber material to tear in each range unit. The tensile strength range of thermally vulcanized solid silicone rubber is between 4.0-12.5MPa. The tensile strength range of fluorosilicone rubber is between 8.7-12.1MPa. The tensile strength of liquid silicone rubber ranges from 3.6-11.0MPa.

Fourth, tear strength

Resistance to enlarging incisions or nicks when applying force on a notched sample. Even after being cut and placed under extremely high torsional stress, the heat-vulcanized solid silicone rubber can not be torn. The tearing strength range of hot sulfurized solid silicone rubber is between 9-55 kN / m. The tear strength of fluorosilicone rubber is between 17.5-46.4 kN / m. The tear strength of liquid silicone rubber ranges from 11.5-52 kN / m.

Five, elongation

Usually refers to "limit elongation at break" or the percentage increase from the original length when the sample breaks. Thermally vulcanized solid silicone rubber generally has an elongation in the range of 90 to 1120%. Fluorosilicone rubber generally has an elongation between 159 and 699%. Liquid silicone rubber generally has an elongation between 220 and 900%. Different processing methods and choice of hardeners can greatly change their elongation. The elongation of silicone rubber has a lot to do with temperature.

Operation time

The operating time is calculated from the moment the colloid is added to the vulcanizing agent. This operation time and the subsequent vulcanization time are actually not completely bounded. The colloid has undergone a vulcanization reaction from the moment the vulcanizing agent is added. This operation time means that the 30-minute vulcanization reaction of the product can not affect the quality of the finished product. Therefore, the more time saved during product operation, the better for the finished product.

Seven, curing time

In some places it is said to be curing time. That is to say, after such a long time, the vulcanization reaction of the silica gel has basically ended. This is basically over, which means that the product is ready for use, but in fact, a small part of the curing reaction has not yet ended. Therefore, products made of silicone rubber, such as silicone molds, are usually put into use for a period of time.

There are many factors that affect the quality of silicone products, and choosing a good liquid silicone product production equipment is even more important.