With superior physical properties and cost-saving benefits, styrenics can already be found in a diverse portfolio of medical devices. Styrolution's Bernd Elbert looks at how its polymers and solutions are improving quality in a range of applications, from catheters to diagnostic machines.
Cardiovascular and respiratory devices, urine containers and inhaler housings - more and more device manufacturers are recognising and exploiting the benefits of styrenic solutions throughout the healthcare sector. And when looking at the physical properties of styrenic materials, it's easy to see why; whether applications have the softness of catheters, the rigidity of drip chambers or are film-based like collection bags, using a styrenic structure to form them offers numerous advantages.
Styroflex's high kink resistance, excellent bonding behaviour and density make it suitable for soft devices such as corrugated, IV and multilumen tubing. With its clarity, processability and adhesiveness, when combined with Styrolux, it lends itself well to rigid applications like drip chambers and connectors. In film products such as IV bags, its lack of material migration and increased elasticity again make it preferable to alternatives.
As one of the global leaders in styrenics, Styrolution offers a diverse portfolio of specialty products that offer unique advantages for the design, manufacture and use of medical devices. The company has worked hard to ensure that its solutions overcome a lot of the issues experienced by similar polymers.
"Material bonding is one of the most important considerations in a lot of medical devices," says Bernd Elbert, new business development manager of healthcare and diagnostics at Styrolution. "For example, within an IV set, there is medical tubing that needs to be connected to the drip chamber, but the connection between the two parts often fails, resulting in leakage and a loss of the drug. The unique polarity of styrenics allows easy bonding to other polymers."
Styrolution's Styroflex offers rubber-like mechanics, making it an important material for any applications requiring a degree of softness, such as medical tubing. By adding small amounts (3-8%) to other polymers, it's possible to improve their mechanical properties.
"As mentioned, bonding is a general problem within the medical industry, and anything that goes some way towards addressing this could become an integral component in a range of devices," says Elbert. "Another area for consideration is colour compensation after gamma sterilisation. Most polymers turn a temporary shade of yellow after irradiation, and recovery can take up to 65 days. Using Styrolux (styrene-butadiene copolymer) or Zylar (methyl methacrylate butadiene styrene), only a slight colour shift is observed. This is a huge benefit for customers, who are able to reduce the inventory times of gamma-irradiated items."
In addition to their functional properties, styrenics also offer other benefits, such as cost and energy savings. Compared with other polymers, processing takes place at a much lower temperature, starting at 170°C, and, coupled with the fact it doesn't need to be pre-dried, energy costs are drastically reduced as a result. Styrenics' density advantage in comparison with other commonly used materials offers customers additional value.
For Elbert, regulatory compliance is just as important in styrenic-based devices as their physical benefits. "All styrenic materials for healthcare offer full conformity with medical policy," he says. "They fulfil a range of regulations, including ISO 10993, USP class VI and FDA guidelines, as well as EU and Japanese pharmacopeia.
"We also have dedicated regulatory staff to support healthcare customers, because when they spend a lot of money on the development and design of a new application, they don't want to find they fail the regulatory tests right before it goes to commercialisation."
Elbert believes styrenics will be able to demonstrate their benefits in rapidly rising technologies such as 3D printing, mobile platforms and wireless solutions. If Styrolution is able to integrate its polymers into such innovations with the same level of success as it has had with more traditional devices, then it's clear the industry as a whole stands to benefit.
