Soft Elastic News 01/2020 | TPE Properties
as we wish you the very best for a successful new year, we are continuing our analysis of certain, individually-adjustable property profiles of TPE compounds which could be essential for certain products, applications and uses. Accordingly, we are addressing the properties of sterilizability, adhesion, and conformity within the framework of this newsletter.
The right property for any application, Part 2
In medical technology and pharmaceuticals in particular, sterilizability is an elementary factor. Even the raw materials must be sterilizable when developing new products and packaging for these markets. This applies for all conventional sterilization methods. This requires the following properties:
Sterilization with hot vapor is at 121 or 134 °C and overpressure of up to three bar in the autoclave. When the vapor condenses on the item to be sterilized, energy is released which damages the microorganisms. Hot vapor sterilization at 134 °C is the most popular method of sterilizing reusable medical products.
High-energy, ionizing gamma irradiation deactivates the microorganisms. When this low-temperature method is applied, the minimum radiation dose must be observed. But not all plastics are suitable for multiple sterilization by gamma rays. Soft PVC for instance is prone to yellowing. But also swift ageing and brittleness are possible results of the gamma irradiation. This method is only applied industrially and almost exclusively for disposable items.
In order to prevent any negative impacts, the material formulae need to be compiled very carefully using stabilizers and other supporting ingredients – as is the case with the PROVAMED® portfolio offered by Actega DS. Extensive tests of the various variants comparing gamma irradiation, autoclaving and gassing with ethylene oxide indicate the resistance displayed by these materials to signs of wear. Tests on PROVAMED® compounds indicate that tensile strength remains virtually unaffected even after irradiation with 50 kGy. The high temperatures in the autoclave can even have a positive effect on the relaxation and crystallization processes of some polymers contained in the TPE recipe. This can increase tensile strength and elongation at break. Similar effects have been detected when gassing with ethylene oxide.
Media contact and increased temperatures are maintained. Against this background ACTEGA DS included adhesion-optimized variants in the PROVAMED® TPE portfolio.
These transparent, soft elastic, adhesion optimized TPE not only display outstanding adhesion to a variety of plastics, including polycarbonate (PC) and acrylonitrile butadiene styrene copolymer (ABS); it also complies with the relevant regulations and guidelines prevailing in this sensitive industry in terms of biocompatibility, toxicity and patient safety. What's more, the adhesive properties have been improved to the extent that they are maintained even at continuous media contact and increased temperatures.
Accordingly, our TPE are also certified for applications which involve contact with food. With an innovative range of TPE materials, care is taken to refrain from using PVC, ensuring sustainable production, resource and energy efficiency, and adherence to all provisions and limit values specified by the EU or the FDA. This also applies for the high demands made of medical grade materials for use in medical technology, pharmaceuticals, and personal care. On the one hand, it concerns tested bio-compatibility and physiological safety in accordance with ISO 10993 and USP Class IV, whereby not only compliance with technical requirements is examined but also how compatible the material is. In accordance with the Medical Products Directive MDD 93/42 EEC, this biological test is always necessary when the patient comes into direct contact with the material/product.
Furthermore, these raw materials must also be conformant with the FDA and be free of heavy metals. They should not contain silicone, latex or phthalates. Chemical and media resistance represent further features. After all, sterilizability of materials is a must in the medical environment – as indicated above.
At ACTEGA DS, extensive research and development management is available from the initial idea and the customer’s requirement catalog which provides support of each individual step from the initial material approaches through test specimens and test rods, in-house tests, quality control and analytics, as well as technical service on site, until the material has been optimized for the respective requirement profile and all certifications and approvals have been obtained.
Talk to us about your product idea and its respective requirement profile.