Automotive Lightweight Recycled Composite: Carbon Fiber Reinforced Materials

## Automotive Lightweight Recycled Composite: Carbon Fiber Reinforced Materials

### Introduction

Recycled carbon fiber reinforced plastics (rCFRP) offer significant weight reduction for automotive applications while utilizing waste materials from aerospace and industrial sources.

### Recycled Carbon Fiber Sources

**Primary Sources**:
– Aerospace manufacturing scrap (prepreg offcuts)
– Wind turbine blade decommissioning
– Automotive production waste
– Sporting goods manufacturing

**Fiber Properties**:
– Length: 5-50 mm (chopped)
– Tensile strength: 80-95% of virgin fiber
– Modulus: 90-98% of virgin fiber
– Surface treatment: Often degraded

### Composite Manufacturing

**Recycled Fiber Processing**:
1. Size reduction (milling or chopping)
2. Fiber length classification
3. Surface reactivation (plasma or chemical)
4. Sizing application (compatibilizer)

**Compounding Methods**:

*Twin-Screw Extrusion*:
– Fiber feeding via side stuffer
– Gentle screw configuration
– Vacuum venting for moisture
– Strand pelletizing

*Long Fiber Thermoplastic (LFT)*:
– Pultrusion process
– Fiber length: 10-25 mm
– Higher mechanical properties
– Suitable for structural parts

### Material Properties

**Mechanical Performance**:

| Property | rCF/PP | rCF/PA | rCF/PC |
|———-|——–|——–|——–|
| Tensile (MPa) | 80-120 | 120-180 | 100-150 |
| Flexural (MPa) | 120-180 | 180-250 | 150-200 |
| Impact (kJ/m²) | 15-25 | 20-35 | 18-28 |

**Weight Savings**:
– vs. Steel: 50-70% reduction
– vs. Aluminum: 20-30% reduction
– vs. Virgin CFRP: 30-40% cost reduction

### Automotive Applications

**Structural Components**:
– Seat structures and frames
– Battery enclosures (EV)
– Underbody shields
– Bumper beams

**Semi-Structural**:
– Door modules
– Instrument panel carriers
– Load floors
– Spare tire wells

**Non-Structural**:
– Interior trim
– Engine covers
– Aerodynamic elements

### Challenges

**Fiber Distribution**:
– Achieving uniform dispersion
– Preventing fiber agglomeration
– Orientation control

**Fiber-Matrix Bond**:
– Surface treatment degradation
– Sizing compatibility
– Interface strength

**Cost Optimization**:
– Fiber recovery costs
– Processing energy
– Quality consistency

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**Keywords**: automotive lightweight composite, recycled carbon fiber, CFRP recycled plastic, composite materials