Although most plastics have a low resistance to heat, especially flames, a select few are specifically designed to withstand this type of stress.
In this article, we’ll examine 4 high-performance plastics with high flame resistance. These polymers are the ideal solution for applications that require this specific property, allowing companies to create a safer environment while complying with industry standards.
How do we measure flame resistance?
Developed by Underwriters Laboratories (UL) and recognized worldwide, the UL94 standard governs the flammability of materials through a series of tests used to measure a plastic’s behaviour when in the presence of flames. It evaluates its ability to self-extinguish and its propensity to propagate flames once ignited. Incidentally, many high-performance plastics possess these two properties.
UL94 standard ratings:
(Least resistant to most resistant).
HB: Slow burning on a horizontal specimen; burning rate < 76 mm/min for thickness < 3 mm or burning stops before 100 mm
V-2: Burning stops within 30 seconds on a vertical specimen; drips of flaming particles allowed.
V-1: Combustion stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they're not inflamed.
V-0: Recognized as the ultimate flame resistance rating. Burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they're not inflamed.
For even more resistance:
(Least resistant to most resistant).
5VB: Burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimen may develop a hole.
5VA: Burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimen may not develop a hole.
4 flame resistant plastics
Polycarbonate
Polycarbonate is a clear thermoplastic often used in the manufacture of protective screens and machine guards for the industrial sector. Its impact resistance is excellent—250 times greater than that of glass, while being 50% lighter. Despite some similarities, polycarbonate's flame resistance is far superior to that of acrylic.
Although polycarbonate is available in various grades, the general-purpose type (thickness equal to or greater than ⅜ʺ) is rated UL94 V-0.
PEEK (polyetheretherketone)
PEEK is a high-performance plastic from the polyaryletherketone family often used in the aerospace, nuclear, chemical, transportation and food sectors, among others. It’s very rigid and has superior mechanical properties. It also has excellent heat resistance, performing well even when exposed to continuous temperatures of up to 482 °F (250 °C). PEEK is also an excellent choice when high chemical resistance is required. PEEK is rated UL94 V-0.
PVDF (Polyvinylidene fluoride)
Polyvinylidene fluoride is an advanced polymer from the fluoropolymer family mostly used because of its impressive chemical resistance. Click here to learn more about chemical-resistant plastics.
PVDF has excellent flame resistance and is rated UL94 V-0.
PTFE (Teflon)
Although most plastics have a low resistance to heat, especially flames, a select few are specifically designed to withstand this type of stress.
In this article, we’ll examine 5 high-performance plastics with high flame resistance. These polymers are the ideal solution for applications that require this specific property, allowing companies to create a safer environment while complying with industry standards.
To get the facts about PTFE, see our article: 4 Myths about Teflon.
As mentioned above, although these 5 plastics are all excellent solutions for applications that require flame resistance, the choice of materials should always be based on mechanical needs. It's therefore essential to refer to a plastic’s technical data sheets to ensure that it has the correct UL94 rating.
