Making the grade: The importance of quality assurance
Fabian Herter, marketing manager for ELIX Polymers, a manufacturer of Acrylonitrile-Butadiene-Styrene (ABS) resins and derivatives, demonstrates the importance of quality assurance and technical value services for pre-coloured ABS in healthcare applications.
In the case of medical ABS grades, quality assurance is essential. It covers all pre-coloured formulations, including the colour recipes. Colour stability is achieved through a purpose-developed material selection and homologation process, testing on all incoming raw materials, intermediate control during manufacturing, and extended testing procedures on final compounds.
Processors can take one of two approaches when it comes to choosing a medical grade of ABS: They can take a pre-coloured product, or they can take an ABS in its natural colour and blend it themselves during moulding, using a colour masterbatch. To reduce their exposure to risk in regulatory compliance, several medical OEMs prefer pre-coloured medical ABS. It is important to guarantee the biocompatibility of the complete material formulation, including the additives and the complete colour recipe.
Even though the concentrations of a certain substance in a natural ABS and in a colour masterbatch may separately comply with relevant legislation, the maximum concentration limits may be exceeded in the resulting coloured ABS when blending the natural ABS with the masterbatch to achieve the target colour. In addition, use of masterbatch can increase the risk of non-compliance because there may be interaction among components - something that is not always easy to predict. These risks are minimised with pre-coloured ABS, as the compliance is verified and certified on the final coloured material formulation. Tests of the biocompatibility of the coloured grades are necessary of medical ABS in accordance with ISO 10993-1 and USP class VI.
Reduction of complexity is a natural consequence of having just one partner providing multiple aspects of value. The medical OEMs don’t need to involve and manage different parties when working with pre-coloured solutions; they do not have to obtain separate declarations from each different supplier or evaluate the risks of potential interaction between substances provided by different suppliers. They can get all the relevant certifications, covering the complete material formulation, in one step, from a single source. This also results in a higher warranty for medical OEMs.
Batch production with emulsion process makes product traceability much easier than with production in big run sizes typical of the mass polymerisation process. Batch production makes it possible to conduct specific tests on individual batches, in accordance with customers’ specific requests. Moreover, batch sizes can be more easily adapted to customer needs and resulting lead times are shorter than average industry lead times.