Factors affecting silicone products
1、 Viscosity. Explanation of technological terms: The volume characteristic of a liquid, quasi liquid, or quasi solid substance that resists flow, that is, the internal friction or flow resistance between molecules when flowing under external forces. Usually, viscosity is directly proportional to hardness.
2、 Hardness. The ability of a material to resist hard objects pressing into its surface locally is called hardness. Silicone rubber has a Shore hardness range of 10 to 80, which gives designers ample freedom to choose the required hardness to best achieve specific functions. Mixing polymer substrates, fillers, and additives in different proportions can achieve various intermediate hardness values. Similarly, the time and temperature of heating and curing can also change the hardness without damaging other physical characteristics.
3、 Tensile strength. Tensile strength refers to the force required per range unit to cause a rubber material sample to tear. The tensile strength range of hot vulcanized solid silicone rubber is between 4.0 and 12.5MPa. The tensile strength range of fluorosilicone rubber is between 8.7 and 12.1 MPa. The tensile strength range of liquid silicone rubber is between 3.6 and 11.0MPa.
4、 Tear strength. The resistance to the expansion of a cut or notch when applying force to a sample with a cut. Even after being cut open and placed under extremely high torsional stress, the thermally vulcanized solid silicone rubber can remain intact. The tear strength range of hot vulcanized solid silicone rubber is between 9-55 kN/m. The tear strength range of fluorosilicone rubber is between 17.5 and 46.4 kN/m. The tear strength range of liquid silicone rubber is between 11.5-52 kN/m.
5、 Elongation. Usually refers to the "ultimate fracture elongation" or the percentage increase relative to the original length when the sample breaks. The elongation range of hot vulcanized solid silicone rubber is generally between 90% and 1120%. The general elongation of fluorosilicone rubber is between 159 and 699%. The general elongation of liquid silicone rubber is between 220 and 900%. Different processing methods and the selection of hardeners can greatly change their elongation. The elongation of silicone rubber is closely related to temperature.
6、 Operation time. The operation time is calculated from the moment when the colloid is added to the vulcanizing agent. There is actually no complete boundary between this operation time and the subsequent vulcanization time. The colloid undergoes 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. So the more time is saved during product operation, the more beneficial it is for the finished product.
7、 Vulcanization time. Some places may say it's the curing time. That is to say, after such a long time, the vulcanization reaction of silica gel has basically ended. This basically ends, which means that the product is already available, but in fact, there is still a small portion of the curing reaction that has not yet ended. So products made of silicone rubber, such as silicone molds, usually need to be left for a period of time before being put into use.
Silica gel is a kind of amorphous silicon dioxide, and the dust content in the workshop should be controlled to be no more than 10 mg/m3. Air exhaust should be strengthened, and masks should be worn during operation.
The superior performance, coupled with the fact that silicone is a non petroleum product and does not rely on increasingly scarce petroleum resources, has made silicone products a substitute for similar plastic products.
Ratio of silicone vulcanizing agent. Silicone rubber is the most common two component vulcanized silicone rubber.
Viscosity. Explanation of technological terms: The volume characteristic of a liquid, quasi liquid, or quasi solid substance that resists flow, that is, the internal friction or flow resistance between molecules when flowing under external forces. Usually, viscosity is directly proportional to hardness.