Recycled TPU Elastomer Footwear Grade: Sole Manufacturing Process and Durability

## Recycled TPU Elastomer Footwear Grade: Sole Manufacturing Process and Durability

### Introduction

Thermoplastic polyurethane (TPU) recycled from industrial scrap and post-consumer products offers excellent properties for footwear sole applications. This article covers manufacturing processes and durability performance.

### Material Properties

**Mechanical**:
– Hardness: 80-95 Shore A
– Tensile strength: ≥25 MPa
– Tear strength: ≥50 kN/m
– Abrasion resistance: <100 mm³ (DIN 53516) **Processing**: - Injection temperature: 180-210°C - Mold temperature: 40-60°C - Cycle time: 30-60 seconds ### Recycling Sources **Industrial Scrap**: - Extrusion edge trim - Injection molding sprues and runners - Off-specification batches **Post-Consumer**: - Used footwear soles - Industrial belts and hoses - Automotive interior components ### Manufacturing Process **Reprocessing**: 1. Size reduction (5-10mm flakes) 2. Washing and drying 3. Melt extrusion with additive package 4. Pelletizing 5. Quality testing **Sole Production**: 1. TPU pellet drying (80°C, 2-4 hours) 2. Injection molding into sole molds 3. Cooling and demolding 4. Surface treatment (if required) 5. Assembly with upper ### Durability Testing **Abrasion**: DIN 53516 rotating drum test **Flex Resistance**: Ross flexing (300,000 cycles) **Compression Set**: 22 hours at 70°C **Hydrolysis Resistance**: 85°C/85% RH aging ### Brands Using Recycled TPU - Adidas (Parley collection) - Nike (Space Hippie) - Allbirds (Dasher series) - Veja (Campo Chrome Free) --- **Keywords**: recycled TPU elastomer, footwear sole, TPU manufacturing, recycled rubber sole,durability testing