The term elastomer is generically used to mean natural or synthetic materials that have the chemico-physical properties of the caoutchouc (or natural rubber), the most peculiar of which is the ability to undergo big elastic deformations, i.e. they can be stretched twice their length, and return to their original dimension when the stress is released.
The thermoplastic elastomers, introduced on the market in the late 60s, are polymeric materials which combine the typical characteristics of elastomer with the ones of thermoplastics, primarily the complete recyclability: unlike other elastomers, which for this reason, are named “thermoset” , the thermoplastics can be melt and reprocessed many times.
Thermoplastic Elastomers can be modelled in the desired shapes by means of the classical transforming technologies used for plastic materials: the most common are injection moulding and extrusion.
The most used TPE belong to the following families:
- Styrenic block copolimers (TPE-S)
- Copolyesters (COPE)
- Polyurethanes (TPU)
- Polyamides (PEBA)
- Polyolefin (TPO)
The THERMOPLASTIC VULCANIZATES are thermoplastic elastomers which have undergone a special chemical process called cross-linking, which causes the creation of chemical bonds between the molecules and confers better physical- mechanical properties to the material. In comparison to the TPEs, TPVs feature better elasticity, heat and fatigue resistance.
Forprene®, the TPV material manufactured by SOFTER, is made up of an elastomeric phase (dynamically vulcanized EPDM) which is deeply dispersed in a polyolefinic thermoplastic matrix. The combination of these two phases determines a real plasto-elastomeric alloy characterized by high performance and extremely easy processability. The elastomeric phase gives to the material typical rubber-like properties such as elastic recovery and softness, while the thermoplastic matrix makes it totally recyclable.
See here below the chart summarizing the SO.F.TER. TPE range.
|Hardness range||25 ShD ÷ 70 ShD||20 ShA ÷ 60 ShD||2 ShA ÷ 60 ShD||25 ShA ÷ 40 ShD||65 ShA ÷ 60 ShD|
|Operating temperatures||-45 ÷ 150 °C||-40 ÷ 130 °C||-50 ÷ 120 °C||-50 ÷ 60 °C||-40 ÷ 70 °C|
|Grades for injection moulding||x||x||x||x||x|
|Grades for extrusion||x||x||x||x||x|
|Grades for blow moulding||x||x|
|Flame retardant grades||x||x|
|Adhesion on polar polymers||PC, PC/PBT,
EVA, TPU, SEBS
|PP||PP, ABS, PC,
PC/ABS, ASA, PETG,