ETPU is a high-performance foamed material manufactured by introducing microporous structures into a thermoplastic polyurethane elastomer (TPU) matrix via physical or chemical foaming processes. It combines the high elasticity of rubber with the thermoplastic processability of plastics. Despite an ultra-low density ranging from 0.15 to 0.25 g/cm³, it retains outstanding mechanical properties, serving as an upgraded alternative to traditional EVA foams.
Chemical Nature: It is obtained by foaming modification of thermoplastic polyurethane elastomer. Its molecular chains contain both hard segments (formed by diisocyanates and chain extenders) and soft segments (polyester or polyether polyols). The formed microphase-separated structure endows the material with distinctive high elasticity and thermoplastic processability.
Microstructure: It adopts closed-cell honeycomb cellular structure with cell diameters commonly ranging from 50 to 300 micrometers. The cell walls are formed of TPU matrix. This "popcorn bead" structure is the core factor to realize ultra-light weight (60% lower density than traditional materials) and high resilience (resilience rate reaching 60–70%).
Thermoplastic Advantages: Unlike thermosetting rubber, scraps and offcuts can be melted, re-granulated and recycled, complying with the development trend of circular economy. Besides, no cross-linking agent is required during production, resulting in remarkably lower VOC emissions than chemically foamed EVA materials.