Articles

Polymer Sterilization Table

Entec Polymers supplies many different thermoplastic materials into the medical market. While the end use applications are varied, many of them, often disposable devices, will require some type of sterilization. There are several different types of sterilization techniques used, with gamma, E-Beam, ethylene oxide, dry-heat and steam sterilization being the most common. Each sterilization method has its own advantages and disadvantages in regard to cost, effectiveness, sterilization time, and area of suitability. In addition, the type of thermoplastic material being sterilized must also be considered because not all polymers are suitable for all sterilization methods. For example, polycarbonate and polyesters are not very suited for steam sterilization because the combination of water and temperature will cause hydrolytic degradation, embrittling the polymer. Some materials, like polyethylene, are not well suited for dry-heat sterilization because the high temperatures used will cause the material to soften and distort. Gamma sterilization is also very commonly used, but many materials will discolor (yellow) after the sterilization cycle, although this phenomenon is well understood, and the discoloration can be improved by the addition of blue color tints.

For these reasons, it is important for the designer or producer of the medical device to understand what their sterilization requirements will be so that they can work with their material suppliers to select the not only the best material that meets the part requirements, but also one that is appropriate for their intended sterilization technique. Because of this, Entec Polymers has put together a Sterilization Table that can provide basic information on the suitability of a variety of different polymers to the commonly used sterilization methods. While this table is a good general overview, and can provide initial guidance, Entec Polymers engineers recommend that customers do their own sterilization evaluations as different grades of a material, or different suppliers products, may perform better or worse based on their specific formulation and additive package. Nonetheless, this Sterilization Table can help our customer more quickly identify potential polymer types to consider for their application based on the sterilization method to be use in the application.

Download Now!