Polymers are among the most widely used materials in the medical industry today. It is estimated that more than half of all medical products currently in use are made of polymer materials.
Polymers can be used in a myriad of different ways. For example, due to their low weight and ease of processing, they not only make work easier in general, but also are also safe when used by patients and medical personnel due to being resistant to breakage. Used for disposable products such as syringes, containers, catheters, and respiratory masks, they are indispensable given the high hygiene requirements in hospitals. Today medical instruments for use during surgery and even prostheses are made of polymers.
In addition, polymers can be manufactured in almost any colour, which makes it easier to distinguish between similar-looking products and prevents confusion. Specialty polymers, all of which are adapted to their specific purpose, have found their way into healthcare technology.
Polymers in reusable medical devices can be sterilised and reused relatively easily. However, the demands placed on the material are considerably high, as conventional polymer materials often malfunction in practice. Medical professionals often complain that polymer components malfunction after the parts have been exposed repeatedly to solvents. The components can exhibit cracking, become discoloured or, at worst, even break.
Chemicals can affect a polymer in various ways. For example, a polymer material may be resistant to one chemical (ie suffer no loss of their properties or become discoloured) but can break easily when exposed to a different chemical. This phenomenon can occur, for example, when medical devices are repeatedly wiped with disinfectants.
In contrast to plastics such as PC and ABS, transparent polyamides are not susceptible to stress cracking due to their high chemical resistance. After various tests with the disinfectants, the surfaces of the polyamide samples remained unchanged. All other plastics tested exhibited stress cracking, discolouration, or deformation after coming into contact with a number of test media.
Reusable over disposable
Reusable medical devices or medical instruments carry a certain risk of cross-contamination, which is often why only single-use products are used. This creates a large amount of waste. If a product is to be reusable, it must be reliably rid of germs. To ensure this, the instruments and products must be sterilised.
There are various ways to do this when working with reusable products: ethylene oxide, gamma radiation, plasma or hot steam. The law prescribes exactly which methods may be used for which applications.
Transparent plastics such as PC, ABS, PMMA, PS and SAN, but also ordinary amorphous PA, for example, are not suitable for repeated steam sterilisation. The number of transparent plastics that are able to withstand steam sterilisation multiple times is very small. Known conditionally transparent plastics are PSU, PEI and PESU. EMS-Grivory has now developed a new highly transparent high-performance polyamide for precisely this purpose, which can be steam sterilised several hundred times and is therefore reusable.
The degree of reusability of medical devices and instruments determines the choice of polymer used in their manufacture. If the polymers selected are sterilised no more than five times, all products listed in ‘Fig. 2’ are suitable. PSU and TR HT 200 are suitable for multiple sterilisation (≤ 500 cycles), whereby TR HT 200 has better transparency, is significantly more ductile and easier to process. Components made of PC have a similar transparency to TR HT 200 but can only be steam sterilised to a limited extent (≤ 5 cycles).
EMS-Grivory says this makes Grilamid TR HT 200 the world’s first transparent polyamide that can be steam sterilised several hundred times. This product is a BPA-free, transparent high-performance polyamide that can be easily processed using thermoplastic processing methods. The core properties of the new Grilamid TR HT 200 are:
For these reasons, the new Grilamid TR HT 200 can be used in a wide range of applications. It can be utilised for example, for reusable applications that require high transparency, such as respiratory masks, protective visors, pump containers, filters, valves, containers, boxes and toolboxes, inspection windows and much more.
In this way, Grilamid TR HT 200 contributes in general to a longer service life of medical applications.