Views:204 Author:Site Editor Publish Time: 2020-06-05 Origin:Site
In the present industrial society, silicone kitchenware is indispensable to life. Today, we will shed light on the factors that affect the quality of silicone kitchenware.
Viscosity refers to the volumetric characteristics of liquids, pseudo-liquids or pseudo-solids that resist flow, that is, the internal friction or internal resistance between molecules when flowing under the action of external forces. Normally, viscosity and hardness are proportional.
The ability of a material to locally resist the pressing of hard objects into its surface is called hardness. Silicone rubber has a Shore hardness range of 10 to 80, which gives designers sufficient freedom to choose the required hardness to best achieve a specific function. Mixing polymer substrates, fillers and additives in different proportions is able to achieve various intermediate hardness values. Similarly, the time and temperature of heat curing can also change the hardness without destroying other physical characteristics.
Tensile strength refers to the force required per unit of range to cause a piece of rubber material to tear. The hot-vulcanized solid silicone rubber has a tensile strength range between 4.0 MPa and 12.5 MPa. The tensile strength of fluorosilicone rubber is between 8.7MPa and 12.1MPa. The tensile strength of liquid silicone rubber ranges from 3.6MPa to 11.0MPa.
Tear strength refers to the resistance to the expansion of a cut or score when a force is applied to a sample with a cut. Even after being cut and placed under extremely high torsional stress, the thermally vulcanized solid silicone rubber will not be torn. The hot-vulcanized solid silicone rubber has a tear strength ranging from 9 kN / m to 55 kN / m. The tear strength of fluorosilicone rubber ranges from 17.5kN / m to 46.4kN / m. The tear strength of liquid silicone rubber ranges from 11.5 kN / m to 52 kN / m.
Generally, the elongation refers to the "limit elongation at break" or the percentage of increase relative to the original length when the sample breaks. Hot-vulcanized solid silicone rubber generally has an elongation range of 90% to 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 choice of hardener can greatly change its elongation. In addition, the elongation of silicone rubber has a great relationship with temperature.
The operating time is calculated from the moment the colloid being added to the curing agent. There is actually no complete limit between this operating time and the following vulcanization time, because the colloid has been vulcanized from the moment the vulcanizing agent being added. Therefore, the more time saved during the operation of the product, the more beneficial it is to the finished product.
After a long time, the vulcanization reaction of silica gel is basically over. to put in differently, the product is already available. As a matter of fact, there is still a small part of the vulcanization reaction that has not yet ended. Therefore, products made of silicone rubber, such as silicone molds, are usually placed for a period of time before being put into use.