Silicone (MQ, VMQ, PVMQ)
Description:
Silicone rubber is a synthetic polymer primarily made of silicon (Si), oxygen (O), carbon (C), and hydrogen (H). Its backbone structure consists of repeating siloxane units (–Si–O–Si–), which give it flexibility, thermal stability, and biocompatibility—critical properties for medical device applications.
One notable property of silicone rubber is its resistance to extreme heat and cold. It maintains its shape and function in temperatures from -60°C to over 200°C. Other materials commonly degrade or lose flexibility in these environments.
Silicone rubber is also suitable for applications involving skin contact or internal use in the body. It’s commonly found in the medical field, in tubing, implants, and seals. The food industry also relies on silicone rubber. Techno Ad offers silicone compounds that meet international regulatory standards, including FDA 21 CFR 177.2600 for food contact, USP Class VI for medical devices, and ISO 10993 for biocompatibility. Compliance with BfR and EU 10/2011 also ensures suitability for European food-grade applications.
Its non-toxic nature and heat resistance mean it can be used in bakeware, kitchen tools, and food-grade tubing.
Other industries like aviation and electronics use silicone rubber. It insulates electricity and is reliable in changing environments. Whether used for insulation, protection, or structural use, silicone rubber is a dependable material across various sectors. It is so versatile, partly thanks to its ability to be easily molded and colored. This allows for customized solutions tailored to specific industry needs.
Silicone rubber is also highly resistant to water, UV, radiation, and many chemicals. This expands its range of uses. Its low toxicity and hypoallergenic properties make it ideal for sensitive environments.
Physically, silicones are based on silicon, an element derived from quartz. To create this class of synthetic elastomers, pendant organic groups such as methyl, phenyl, and vinyl are attached to silicon atoms. The addition of side chains can achieve significant variations in properties.
Silicones have:
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Excellent heat and ozone resistance
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High dielectric stability
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Resistance to many oils, chemicals, and solvents
Of all elastomers, silicones possess the best property of flexibility at low temperatures. However, silicones also have some weaknesses like low tensile strength, and poor tear and wear resistance.
Common Uses:
Silicone is found:
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In contact with food or beverages as elastomers that pass the 21.CFR 177.2600 specification
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In medical systems which require compliance to USP CLASS VI
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Automotive systems like boots and oil filter valves
Properties:
Standard Compound: -50°C (-58°F) to 225°C (437°F)
Special Compound: -100°C (-150°F) to 300°C (572°F)
Hardness: 25 to 90 Shore A
ASTM D1418 Designation: Q, MQ, VMQ, PVMQ
ASTM D2000 Designation: FC, FE, GE
Standard Colors: Rust
Optional Colors:
Production:
Standard silicone compounds are usually peroxide-cured. Platinum-cured compounds offer better flexibility and very low volatile matter, and are usually applied in medical systems or other areas that require low volatile matter. However, they need to be produced in a clean room with the more expensive platinum catalyzer, so they are more expensive than those cured with peroxide.
Advantages:
Silicones perform well in engine and transmission oil (mineral oil), diluted salt solutions, moderate temperature water, dry heat, ozone environments, and are weather resistant.
Limitations:
Silicones do not work well in concentrated acids and alkalis, petroleum oils/fuels, ketones, and in steam environments over 120 °C.
Silicone Seals
Silicone seals are often used for their flexibility and long-term resilience. Silicone rubber performs well as a gasket or seal because, even in demanding conditions, it doesn’t harden or crack. Its ability to conform to irregular surfaces without losing shape is also useful. This flexibility means components can move or shift without compromising the seal. This is valuable where there are many changes in pressure, vibration, or temperature.
Silicone seals can maintain their properties over long periods. Typical silicone rubber formulations used for seals operate between -60°C and +230°C. Depending on the compound, Shore A hardness can range from 20 to 90, allowing for a balance between flexibility and compression strength. Other materials degrade quickly, but silicone resists aging, ozone, and environmental exposure. It continues to perform even in outdoor and industrial settings where durability is prized.
Silicone’s resistance to low and high temperatures means that seals are reliable in cold storage, engine compartments, and high-heat production environments. Engineers use silicone seals in automotive, aerospace, and industrial machinery.
Overall, silicone rubber is effective for seals because it is flexible, durable, and resistant to environmental stress. It helps prevent leaks, protects sensitive components, and allows for stable operations. Silicone seals are available in a wide range of sizes and shapes. They’re suitable for both standard and highly specialized applications. The ease of installation and low maintenance contribute to their popularity in engineering and manufacturing.
Liquid Silicone Rubber
Liquid silicone rubber (LSR) is a particular form of silicone with a smooth texture. LSR is noted for its cleanliness, making it suitable for industries prioritizing hygiene.
LSR is especially useful when high precision is required. It can be easily shaped using injection molding. This makes it ideal for producing parts with fine features or tight tolerances. LSR is a liquid before curing, so it can flow into very detailed or complex molds. This makes it a good fit for electronics, medical devices, and micro-components.
Sterility is another key benefit. LSR can be processed in cleanroom environments and withstands sterilization methods (like autoclaving and gamma radiation). It’s widely used for items like medical seals, infant care products, and parts used in laboratories. To meet industry-specific regulatory demands, LSR materials can be formulated to comply with standards such as FDA 21 CFR 177.2600, USP Class VI, ISO 10993, and EU 10/2011.
The optical clarity of LSR allows for transparent and translucent components. This is useful in sectors like lighting and optics.
Compared to standard solid silicone rubber, LSR allows for faster production cycles and better consistency. This improves efficiency and reduces material waste. Industries like healthcare, automotive, and electronics rely on high volume, high precision production. LSR is a practical and dependable solution.
Silicone O-Rings
Silicone O-rings are a sealing solution used in industries where reliability and material stability are important. Their main function is preventing the escape of fluids or gasses between joined surfaces. They’re essential in pressurized systems and dynamic environments.
Due to silicone’s resistance to extreme temperatures, O-rings made from this material are useful in the aerospace, defense, and chemical sectors. Standard silicone O-rings function reliably across -60°C to +225°C. They typically have a Shore A hardness between 30 and 80, with some formulations lower for specific applications. Depending on the grade, silicone offers elongation up to 700%, tensile strength between 7 and 11 MPa, and good resistance to compression set under continuous use. They can be used in high-altitude aircraft systems, for example. Silicone O-rings are also used in medical devices that undergo repeated sterilization.
Silicone O-rings also have good compression set resistance – they return to their original shape after being compressed. Their resistance to ozone and UV exposure makes them suitable for outdoor and long-term use.
Silicone is more flexible and less reactive than other rubber materials. This makes it ideal for sensitive and high-purity applications. O-rings are suitable for fuel systems, lab instruments, and a wide range of use cases. They’re a dependable sealing option where precision and material stability are required.
With years of experience in the rubber sealing industry, Techno Ad provides custom-molded silicone products based on customer drawings and performance requirements. Our silicone compounds are formulated to meet strict material standards, including FDA, USP Class VI, ISO 10993, and more. Backed by engineering support and a commitment to quality, Techno Ad delivers reliable, compliant solutions for medical, food-grade, industrial, and specialty applications.