Medical-grade silicone for tubes and valves
Medical-grade silicone is used for tubing, check valves, valve membranes and connectors in infusion, respiratory and dialysis equipment. The material is soft and flexible, chemically inert and can be steam sterilized repeatedly without deforming or cracking.
For medical device manufacturers, choosing the right type of silicone and processing method determines both patient safety and production efficiency.
Why silicone is preferred in medical applications
Silicone offers high biocompatibility, contains no plasticizers like PVC, has low drug adsorption and is odorless. The material performs reliably over a temperature range from -50°C to 200°C, withstands autoclave sterilization at 121–134°C and retains its elasticity after millions of valve open/close cycles.
Common forms of medical silicone
| Material type | Cure mechanism | Processing method | Typical products |
|---|---|---|---|
| High consistency rubber (HCR) | Peroxide or platinum | Extrusion, compression molding | Tubing, gaskets |
| Liquid silicone rubber (LSR) | Platinum catalyst | Automated injection molding | Valves, membranes, nipples |
| Medical RTV silicone adhesive | Moisture cure | Dispensing, bonding | Tube bonding, sealing |
| Silicone gel | Platinum | Casting, coating | Skin-contact cushions |
Platinum cure or peroxide cure
Platinum-catalyzed silicone produces no byproducts, yielding a clean surface, high clarity and low extractables, and is preferred for applications in contact with fluids and blood. Peroxide systems cost less but require post-curing to remove decomposition byproducts.
Key points to control during processing
- Avoid contamination by sulfur, tin and amines from gloves or molds, which inhibit the platinum catalyst.
- Control Shore A hardness within tolerance, typically from 30 to 70.
- Post-cure to stabilize mechanical properties and reduce volatiles.
- Manufacture in a cleanroom appropriate to the product class.
Documentation to prepare
Materials should have ISO 10993 and USP Class VI certification and a DMF or equivalent documentation from the manufacturer. The plant should agree with the supplier on formulation change notification to ensure the stability of product registration files.
In addition, packaging specifications, storage conditions and shelf life of silicone raw materials should be agreed upon, as two-part LSR compounds can change in viscosity if kept too long.
AMS supplies medical silicone from Shin-Etsu and Dow for tubing, valve and gasket production. Contact AMS Vietnam to receive data sheets and samples.
