7 factors that affect the quality of silicone products

- Apr 25, 2018-

1. Viscosity. Explanation of technical terms: The volume characteristics of liquids, pseudo-liquids or pseudo-solids against flow, that is, internal friction or internal flow resistance exhibited between molecules when they are flowed by external forces. Viscosity is usually proportional to hardness.


2. Hardness. The ability of a material to locally resist the penetration of a hard object into its surface is called hardness. Silicone rubber has a Shore hardness range of 10 to 80, which gives the designer full freedom to select the desired hardness to optimally achieve a specific function. Different mixing ratios of polymer substrates, fillers and auxiliaries can achieve various intermediate hardness values. Similarly, the time and temperature of heat curing can also change the hardness without destroying other physical features.


3. Tensile strength. Tensile strength is the force required in each range unit when tearing a piece of rubber material. The heat-sulfurized solid silicone rubber has a tensile strength in the range of 4.0-12.5 MPa. Fluorosilicone rubber tensile strength range between 8.7-12.1MPa. The tensile strength of liquid silicone rubber ranges between 3.6 and 11.0 MPa.


4. Tear strength. Applying a force on a sample with an incision hinders the resistance of the incision or the incision expansion. Even when cut and placed under extremely high torsional stress, the thermal-vulcanized solid silicone rubber can not be torn. The thermal and vulcanized solid silicone rubber tear strength ranges from 9-55 kN/m. The fluorosilicone rubber tear strength ranged from 17.5-46.4 kN/m. The tear strength of liquid silicone rubber ranges from 11.5-52 kN/m.


5. Elongation. It is usually referred to as the "ultimate rupture elongation" or as a percentage of the original length when the sample breaks. The heat and sulfur type solid silicone rubber generally has an elongation in the range of 90 to 1120%. The general elongation of fluorosilicone rubber is between 159 and 699%. Liquid silicone rubber generally has an elongation of between 220 and 900%. The choice of different processing methods and hardeners can change their elongation to a large extent. Silicone rubber elongation and temperature have a great relationship.



6. Operating time. The operating time is calculated from the moment the colloid is added to the vulcanizing agent. This operating time and the subsequent vulcanization time are in fact not completely delimited. The colloids undergo a vulcanization reaction from the moment the vulcanizing agent is added. This operation time means that the 30 minute vulcanization reaction of the product does not affect the quality of the final product. Therefore, the more time-saving the product operation process, the better the finished product.


7. Curing time. Some places will say it is curing time. In other words, after a long period of time, the vulcanization of the silica gel is almost complete. This is basically the end that the product is already available, but in fact there is still a small part of the curing reaction is not over yet. Therefore, products made of silicone rubber, such as silicone molds, are usually put into use for a while.