VMQ, PVMQ, FVMQ – Silicone Rubber
Silicone rubbers belong to the category of synthetic polymers in which silicon atoms are linked together with oxygen atoms. They are stable in hot air and ozone, in water, in animal and plant oils, and fats. But they do not stand up to low molecular weight esters¹ and ethers, acids and alkalis, along with aliphatic (such as gasoline, propane and methane) and aromatic hydrocarbons (such as benzene, xylene and tolulene).
Silicone rubber displays high thermal resistance and good cold flexibility from −60 °C to 200 °C, but has little tensile strength, elongation or abrasion resistance. FVMQ withstands even low temperature applications up to -80°C. VMQ silicone elastomers are used in demanding thermal applications, and, due to their purity, are especially suited for hygienic uses in the food and pharmaceutical industries like the VMQ 117055. Due to its very good physiological characteristics, silicone is a proven sealing material, especially for butterfly valve seals. Their low breakaway torque ensures reliable switching over their entire lifecycle.
Seals made of liquid silicone (LSR) can even adopt the phenomenon of ultrahydrophobicity. Without a coating or a material change, the mold leaves behind a hill and valley structure in the micron range. The friction-reducing seal surface contributes to significantly easier assembly.
¹ Chemical bond that results from an alcohol and an organic (or inorganic) acid subjected to dehydration