Surgical tubing is often made of silicone because of silicone’s chemical inertness. Silicone tubing manufacturers offer medical-grade and industrial-grade silicone tubes or hose.
One branch in the silicone tubing family tree, platinum cured silicone tubing, is fast becoming the top choice for medical, biotech, pharamaceutical and food and drink processes. Silicone platinum curing, or room temperature vulcanization (RTV), does not produce peroxides or ketones, unlike traditional peroxide curing. The ethanol by-product of silicone platinum curing is easily removed.
The silicone tubing formed by platinum-cured material may not be as strong as peroxide-cured silicone, but it has fewer potential leachables, a smoother surface, less protein binding and better clarity. The main deficiency of silicone tubing is its poor shape memory; if deformed, silicone will keep its deformation instead of returning to its original shape. In this way, latex tubing and other synthetic tubing materials can be better choices than silicone. Still, silicone’s many favorable qualities make it an excellent choice in many applications.
Silicone tubing can be formed in several ways, but one of the most widely used methods is rubber extrusion. Rubber extrusion is the process of using a die to shape rubber materials into usable products. The process of silicone extrusion begins with a collection of raw silicone in a hopper suspended above a conveyance channel. Within that conveyance channel is a long shearing screw. When the rubber is released into the conveyance channel, it is forced down the channel by the screw. As the screw turns, it heats and pressurizes the silicone, causing it to become molten. Once molten, the silicone is ready to be extruded. At the end of the conveyance channel is an extrusion die, which is a metal plate with a specially shaped hole cut through it.
When the silicone is forced through the die, it takes the die’s shape. When it emerges on the other side of the die, the silicone has become newly extruded silicone tubing. The tubing can then be cut to the appropriate length and either prepared for shipment to customers or sent for additional processing if necessary.