Silicone O-Rings
Detailed Explanation of Silicone O-rings (MQ/VMQ/PVMQ) Material Properties
From a material physics perspective, silicone O-rings use silicon as the base material, and silicon's natural source is quartz. During the synthesis of this type of elastomer, organic side-chain groups such as methyl, phenyl, and vinyl groups are grafted onto the silicon atom backbone; the type and connection method of these side-chain groups significantly regulate the material's core properties.Silicone O-rings possess excellent heat resistance, ozone resistance, and corona resistance, while also exhibiting good dielectric stability, making them resistant to the erosion of various oils, chemicals, and solvents. This material maintains excellent flexibility even at low temperatures, but its drawbacks lie in its relatively low tensile strength and abrasion resistance.
Silicone O-rings are also available in metal-detectable versions, with performance specifications identical to standard silicone O-rings. KODA’s silicone O-rings all meet FDA standards and are available in both standard and metal-detectable versions, making them widely adaptable to the stringent application requirements of food and beverage production lines, medical, and pharmaceutical industries.
Curing system: Peroxide vulcanization process
Standard silicone O-rings typically use a peroxide curing process. Platinum curing, on the other hand, imparts superior flexibility while significantly reducing the content of volatile substances. Due to this characteristic, platinum-cured silicone O-rings are widely used in medical systems and other fields with strict limits on volatile substance content.
It should be noted that platinum curing requires a cleanroom environment, and the cost of platinum catalysts is relatively high. Therefore, platinum-cured silicone O-rings are more expensive than peroxide-cured silicone O-rings.
Introduction to the properties of silicone rubber O-ring compounds
| Compounds | Durometer | Color | Temp Range (F) | Description |
|---|---|---|---|---|
| S50-B601 | 50 | Red | -67 to +437 | FDA-Grade |
| S60-C601 | 60 | Red | -67 to +392 | FDA-Grade |
| S70-B001 | 70 | Clear | -76 to +437 | Platinum Cured |
| S70-A601 | 70 | Red | -67 to +437 | FDA-Grade |
| S70-B401 | 70 | Blue | -67 to +392 | ISO 10993-5 Compliant |
| S70-B602 | 70 | Red | -67 to +437 | UL 157 |
| S75-F601 | 75 | Red | -76 to +437 | Metal/X-ray detectable, FDA-Grade |
Recommended working conditions for silicone O-rings
Areas of outstanding performance:
Mineral-based engine oils and transmission fluids;
Diluted salt solutions; Moderate humidity environments;
Dry and hot environments;
Excellent ozone resistance and weather resistance.
Areas where performance was poor:
Highly corrosive media such as concentrated acids and alkalis
Steam environments exceeding 120°C (248°F)
Petroleum-based petroleum products and fuels
Ketone organic solvents
