| Property | Value |
|---|---|
| Temperature range | -30 °C to +135 °C |
| Hardness | 50–90 Shore A |
| Best at | Heat, ozone, weather, flame, chemical resistance |
| Contains fluorine | No |
The Hypalon substitution
A lot of CPE gets specified because a CSM part needed a second source. The two overlap heavily on weather, ozone, and chemical resistance, and CPE generally costs less and processes more predictably. Where the original CSM spec was driven by colour stability or by resistance to strong oxidisers, the substitution needs testing rather than assuming; where it was driven by weather and flame, CPE usually carries it.
Its heat ceiling of roughly 135 °C is a real step up from neoprene, which is the other family it commonly replaces. For a part that was running at the top of neoprene's range and aging out early, CPE is often the cheapest fix available.
How we compound and test it
CPE is peroxide-cured, and peroxide systems are sensitive to residue from sulfur-cured compounds. We keep peroxide-cured compounds clear of sulfur-cured residue on the mixing line, because that interaction shows up as a cure problem, a soft or tacky part, rather than as an obvious contamination one.
Chlorine content drives the balance between oil resistance and low-temperature flexibility. That is a formulation decision we make against your service conditions, and it is the main reason two CPE compounds can behave very differently.
The two mistakes buyers make
The first is expecting nitrile-grade oil resistance. CPE handles incidental oil and many chemicals well; it is not a hot petroleum oil material and a part sitting in it will swell.
The second is ignoring the low-temperature limit. At around -30 °C it stiffens well before neoprene does. Outdoor parts in a northern winter need that number checked against the actual installation rather than a room-temperature bench test.