Marfran, producer of TPE/TPO compounds for food contact and medical use, shares its focus for the present as well as for the future.
Since their first appearance on the market, TPEs have mainly been used in injection moulding and have experienced some difficulties gaining ground in the extrusion world, as this has traditionally been dominated by vulcanised rubber and plasticised PVC. However, in recent years there has been a strong tendency to reconsider TPEs as suitable candidates for several extrusion applications - a trend favoured mainly in the fields of drinking water and medicine because of more stringent hygienic requirements.
In the medical field, the dominant position of plasticised PVC as a raw material to produce medical devices stands as a point of reference to all market newcomers like TPEs, which must conform to many common processing techniques applicable to PVC or enable new applications/alternative processes to be created to carve out their own market space.
Marfran is committed to develop and produce new TPE solutions for strongly regulated applications for both present and future challenges.
The company’s most recent developments have been focused on extrusion grades for many applications in the medical field, for drinking water and other relevant industrial applications. Our current projects are dedicated first and foremost to Marfran TPEs for drinking water applications and to medical compounds, with a particularly strong focus on solvent-bonding products - a complete revolutionary solution for a TPE that until only recently could not be bonded with a solvent.
By working closely with raw material suppliers and investing in new process technologies, Marfran uses the latest innovations to identify new material combinations and develop new possibilities.
Medical compounds
Medical applications are a high-growth TPE sector with major applications in tubing, catheters, intravenous systems, resealable membranes and films.
In the medical industry, the demand for safe and halogen-free polymers such as Styrenic block copolymer-based materials is currently on the rise. The safe and non-toxic properties of TPEs make them an ideal component in the design of medical products, for which superior performance levels and safety are required. TPEs combine flexibility with high performance, while also complying with many food and skin contact regulations due to their inherent low toxicity.
When selecting TPE for medical applications, manufacturers can either choose food contact or medical grades. The current trend seems to be swinging towards medical grades, but awareness about the similarities and differences between both grades is necessary to make the right choices.
Food contact raw materials must be cleared by Regulation (EU) 10-2011, stating whether they are a substance with specific migration limits (SML) or a dual use substance. Medical raw materials have to be compliant with European Pharmacopeia and have their biocompatibility certified according to ISO 10993 and USP class VI. With rapidly advancing technologies and increasing regulatory requirements, today’s customers are asking for more material knowledge and consistent processes in order to minimise variation and improve performance.
The transformation processes for Marfran.Med are carried out in a dedicated cleanroom, which is compliant with ISO 13485; ISO 7 class, according to ISO 14644-1, and Class 10,000 equivalent, according to US FEL STD 209E. The Cleanroom is highly automated, subject to strict cleaning procedures and optical checks for quality control. That means more extensive clean down and line clearance procedures, with the guarantee of process change control and that production only takes place on dedicated lines.
As a leader in the production of compounds based on thermoplastic elastomer compounds (TPE/TPO based on SBS and SEBS), Marfran has a full range of TPE Marfran.Med solutions for medical applications.
TPEs do not easily bond to other materials, such as the substrates polycarbonate (PC) or ABS connectors that are used in standard intravenous tubing sets. Recent developments allow Marfran to propose Marfran.Med grades suitable for both moulding and extrusion, that allow solvent bonding with cyclohexanone or THF.
The challenge of the pandemic and the sanitation of TPE surfaces.
The pandemic has forced all health authorities to reconsider all the criteria for sanitising the environments and therefore the surfaces of all the artifacts used in the medical field.
The most stringent requirements relating to sanitation and sterilisation force us to reconsider the materials and identify new solutions to allow a more efficient and safer sterilisation of the products.
In 2015 Marfran registered a patent on the use of usnic acid in TPE compounds as an antibacterial (WO 2016/020774 A1). The effectiveness of usnic acid has been proven by numerous tests conducted on various compounds, however its organic nature makes it “sustainable” but it also introduces limits on temperatures both for processing and operation.
The increase in the temperatures of the sterilisation cycles requires the use of TPE based on polymers with an average higher molecular weight which, therefore, requires an average higher processing temperature. Thanks to the collaboration with some suppliers, Marfran has developed solutions based on bacteriostatic substances which, due to their inorganic nature, can be used at higher processing temperatures more suitable for TPE compounds with higher molecular weight. The bacteriostatic effect prevents the formation of bacterial biofilm on the surface of the artifacts, facilitating sanitation even with common detergents and making autoclaving more effective and lasting.
The “bacteriostatic” solution can be applied both on materials in contact with food and in the medical field, having no effect of cytotoxicity,
unlike other bactericidal substances. The effectiveness of the bacteriostatic treatment of TE compounds was confirmed by evaluating the antibacterial activity conducted according to ISO 22196: 2011. The results obtained on a Marfran.Med 40A M compound are quite positive, considering the hardness of the chosen compound.
Numerous studies have highlighted the ability of COVID-19 to survive on the surfaces of various materials, even for several days. An antiviral activity measurement test, conducted in accordance with the ISO 21702:2019, highlights a significant improvement in the reduction of COVID-19 on the surface of the Marfran.Med 40A M when treated with bacteriostatic treatments.