Spoiler alert: when comparing polymer plastics suitable for plastic medical devices, thermoplastics are the Mayo Clinic, if you will, while thermosets are a very competent regional health center.
In other words, thermosets aren’t nearly as ubiquitous as thermoplastics but they do have a place in the universe of plastic medical devices. For example, thermosetting plastics like silicone, polyurethane, epoxy and phenolic are ideally suited for plastic medical parts that need rigidity and strength, such as heart valve sizers and tissue diagnostic devices. Their toughness and durability serve them well in these applications.
In a nutshell, the critical difference between thermoplastics and thermosets is how the materials react during the curing process. Thermosets strengthen greatly when cured but create chemical bonds that make them impossible to re-mold This chemical bonding in thermosets makes them more durable and more heat resistant than thermoplastics. In contrast, thermoplastics do not make any chemical bonds during the curing process, making them re-moldable and recyclable.
Thermosets’ ability to retain their shape and strength when exposed to high temperatures set them apart from thermoplastics. In fact, thermosets will often deteriorate before melting when exposed to excess heat. These properties mean plastics can be used as a cost-effective replacement for metals in some applications.
In a nutshell, thermosets generally have greater physical properties than thermoplastics; however they cannot be re-molded or recycled.
Thermoplastics, on the other hand, are the “go-to” plastics of choice for the healthcare industry. They include:
- PEBA: Thermoplastic bio-compatibility
- Acrylic: rigidity, light transmissivity, weather-resistant
- ABS: rigidity and strength on glossy surfaces in non-electrical, low chemical and UV negative applications
- HIPS: impact resistance and durability for printing, gluing, and bonding
- Acetal: dimensionally stable chemical, exceptional creep and wear resistance
- LDPE/HDPE: versatile flexibility for many medical device applications
- TPE: elastic, pliable, low durometer
- Nylon: durable chemical, temperature, and abrasion resistance
- Polycarbonate: transparency, resilience and strength
- Polypropylene: durable, elastic, and insulating transmissivity
- PEBA: Thermoplastic chemical resistance
These are the plastics that AdvanTech uses when making plastic medical devices.