VMQ Silicones is a group of elastomeric materials made from silicones, oxygen, hydrogen and carbon. As a group, silicones have poor tensile strength, tear resistance and abrasion resistance. Special compounds have been developed with exceptional resistance to heat and pressure changes. High-strength compounds have also been made, but their strength is not comparable to conventional rubber.
Some special compounds withstand even higher temperatures.
Silicone compounds are very clean and are used in many food and medical applications because they do not give off odor or taste. Silicone compounds are not recommended for dynamic sealing applications due to the relatively low tear strength and high coefficient of friction.
Siicones can be formulated to be electrically resistant, conductive or flame retardant. Many silicone compounds have a higher shrinkage than normal. That is why production molds for silicone products are often different from molds for nitrile.
Characteristics of silicone compounds:
• Extreme temperature range
• Low temperature flexibility
• Excellent resistance to extreme temperatures from -50 °C to + 232 °C (-58 °F to + 450 °F)
• The retention of properties of silicone at high temperatures is superior to most other elastic materials.
• Resistant to hot air, ozone, UV radiation, engine and transmission oils, animal and vegetable fats and oils and brake fluids.
• Low resistance
• Stays stable in extreme environments
• Material properties remain the same over a wide temperature range
• High temperature resistance
• Extremely suitable for industrial applications
• The rubber with the largest temperature range (-100 °C to more than +300 °C) phenyl silicone rubber
• Superior aging and ozone resistance
• High electrical insulation values
• Wide range of chemical resistances
• Good compression set at higher temperatures
• Restituent for bacteria and fungi
• 54 to 232 °C
• Resistant to oxygen ozone and UV light
• Silicones are generally non-reactive, odorless, tasteless, non-toxic and antifungal. They have also set a high level of flexibility and low compression.
Cons of VMQ:
Low resistance to mineral oils
Silicone rubber is difficult to attach
Poor gas density
Non-resistant to hydrocarbon, based fuels, aromatic hydrocarbons, low molecular weight silicone oils, strong acids and alkalis.
It is known as a mechanically weaker
Poor mechanical performance, sensitive to shear forces and therefore not suitable for dynamic or rotating closure applications.
What is it used for?
History of VMQ silicone
In 1943, Dow Corining (a collaboration of Dow Chemicals and the Corning Glass Company) was the first to produce silicone rubber. Moments later General Electric followed with the production of silicone rubber. They patented their production method.