Materials

Thermoplastic Elastomers (TPE)

Product Description

Also referred to as Thermoplastic Rubber (TPR), TPEs (thermoplastic elastomers) have the properties and performance of rubber, but are processed like plastic. They are ideal for applications such as window and door seals as well as commercial glazing seals. TPEs provide:

Thermoplastic Elastomers (TPEs) are a class of polymers that provide the functional performance of thermoset rubbers, but are processed like plastic. TPEs are flexible materials that can be repeatedly stretched to at least twice their original length at room temperature and return to the approximate length of the original shape upon stress release.

Also referred to as Thermoplastic Rubber (TPR), these elastomeric materials can be easily reprocessed and remolded, offering a level of design and fabrication freedom that is not commonly available to normal thermoset rubber compounds.

Thermoplastic Elastomers provide:

Benefits of choosing TPE over thermoset rubber can include:

Typical TPE products include:

What is TPE Material?

All TPE materials are composed of both crystalline and amorphous domains. These compositions can be either a blend or an alloy of crystalline and amorphous polymers. They can also be block co-polymers containing blocks of crystalline and amorphous domains along the same polymer chain. In this dual domain structure of thermoplastic elastomers, the crystalline domains are typically referred to as the "hard phase" domains, providing the TPEs with their thermoplastic character and acting as the heat-fugitive cross-links.

Contrarily, the amorphous or "soft phase" domains give the TPEs their elastomeric characteristics. Combined, both phases contribute to the overall mechanical and physical properties of a thermoplastic elastomeric compound. However, some key properties can be associated to one phase or the other and can thereby act as a guide in the selection or design of a custom TPE compound.

"Soft Phase" — Elastomeric Properties include:

"Hard Phase" — plastic properties include:

Important Considerations in Selecting a TPE Rubber Compound

Chemical or fluid exposure

Service Temperature

Hardness vs. other property requirements — Don't be fooled

Hardness is defined as a materials' resistance to indenture and is probably the most common property identified with TPE. However, for certain applications, hardness may be the least relevant property that should be considered. Durometer is the international standard for measuring the hardness of rubber, sponge rubber, plastic, and other nonmetallic materials. Many rubbers, soft plastics and TPEs are rated on the Shore A scale. Thermoplastic resins hardness is rated on the Shore D scale.

Other important engineering properties include*:

*while it is true that there is a general correlation between these properties and hardness within a given TPE family, this correlation may not hold across different families of TPE rubber.

Example- It is possible for two different TPE materials to have the same hardness while having a completely different flexural modulus.

Tear Strength

Peel Strength

Compression Properties

Important in sealing and gasket applications, two measurements of a TPE materials performance under compressive loads include:

Both of the above compression properties result from "cold flow" or plastic deformation of the TPE and are affected by time, temperature and fluid or chemical exposure.