The Medical Benefits of Silicone Molding and Silicone Bonding When you first hear of silicone for use in medical procedures your only thought may be of cosmetic surgery, especially enhancement surgery. Ultra-clean medical silicone plays a much larger role in the medical industry than you might expect. Following are a few examples of areas where silicone is currently used in medical applications:
Replacement Cartilage in Knuckle or Toe Joints As part of orthopedic solutions for knees, hips, and elbows. Breast implants Surgical Tubing Catheters Medical Seals, Drains, and Gaskets
Not all silicone applications require the stringent cleanliness and quality found in medical applications. Items being produced for manufacturing applications or general home use do not require this level of purity. Companies who specialize in silicone molding and silicone bonding commonly separate their work into multiple categories or areas within their facilities. The Three Faces of Medical Silicone Molding There are three basic forms of molding which are used for medical silicone molding. These three methods include:
Liquid Injection Molding Compression Molding Transfer Molding
Each form of molding has a unique place in the production of a variety of parts. Liquid injection molding is considered the cleanest and safest form of producing parts. The entire system can remain sealed while the silicone is injected into the molds in two parts. It does not begin to harden until the two parts come together. Since the system is sealed it reduces the introduction of dust, bacteria, and other foreign material. Compression molding appears much more industrial in the process. The silicone is premixed and then forced into the molds in a partially hardened state. These forms of silicone molding are commonly used for o-rings, diaphragms, and other similar items. Silicone Bonding – Putting Silicone Together with Other Materials For many applications silicone must be adhered to another item, usually in the form of metals, plastics, or ceramics. The non-silicone items must be prepared prior to having the silicone added through a
variety of methods. The surface of the items needs to be roughened by abrading or chemical etching. This gives the silicone a surface to grasp and remain sealed to. Silicone does not naturally adhere to these materials so most commonly a bonding agent is sprayed or painted on the part before the silicone is applied. After the parts are prepared they are sent through molding process where the silicone is molded around, or onto, the part. This process is labor intensive but provides for an extremely strong bond which can be used in both medical applications and normal consumer products. Why Silicone Is So Important in Medicine Medical silicone is one of the most inert and clean substances which can be introduced into the body. It is very uncommon for the body to react to a molded silicone product. The challenge with silicone molding and silicone bonding is in the exacting standards required for making reliable parts. When properly manufactured silicone medical products are extremely safe and play a crucial role in orthopedic and cosmetic procedures.