Elastomers are a family of flexible resins generically known as ThermoPlastic Elastomers (TPE), ThermoPlastic Rubbers (TPR), and ThermoPlastic Vulcanizates (TPV). There are many specific types and names of rubbers that have varying chemical makeups and functionality. Vulcanizates can be cured by different processes and have good strength and durability, but cannot be melted and molded again. TPE/TPR resins can be recycled, melted, and made into new products. Wikipedia Link