Composites

How to Estimate Composite Part Cost from Fiber to Finished Part

Composite part cost is driven by material, layup labor, cure time, and autoclave or oven cost. Here is how to build a cost model for CFRP or GFRP parts and where cost reduction is possible.

Composite layup cost per part = material cost (fiber + resin) + labor cost (layup, bagging, debulking) + cure cost (autoclave or oven time) + tool cost amortization + finishing cost. Carbon fiber prepreg: $15-$80/kg depending on fiber grade and tow size. For a 2 kg CFRP part: material cost = 2 x $35 = $70. Layup labor at 0.5 hours/kg x $55/hr = $55. Autoclave cure: 1 cycle on a $300/hr autoclave shared across 10 parts = $30/part. Tool amortization: $5. Finishing: $20. Total: $180.

Fiber volume fraction (FVf) is the primary driver of structural performance. Target FVf for aerospace-grade CFRP: 55-65%. Higher FVf requires controlled consolidation through vacuum bagging and autoclave pressure. At FVf below 50%, matrix-rich areas reduce stiffness and strength. Wet layup processes without autoclave typically achieve FVf 35-50%. Out-of-autoclave prepregs (OOA) with well-executed vacuum bagging achieve 55-60%, closing much of the gap with autoclave processing at much lower capital cost.

Labor is the highest cost driver in manual composite layup. A 48-ply CFRP part requiring precise ply placement and indexing can take 8-16 hours of skilled labor per part. Automated fiber placement (AFP) machines can lay material at 10-50 kg/hr versus a skilled technician's 0.3-0.8 kg/hr. AFP capital cost is $2-$8 million, making it viable only for programs above 200-500 parts per year at significant part complexity. For lower volumes, optimizing manual layup process (kitting, ply books, laser projection) is the cost lever.

Trim allowance and material waste in composite manufacturing is significant. Unidirectional prepreg waste in manual cutout: 15-25%. Woven fabric waste: 10-20%. Automated cutting with nesting optimization: 8-15%. For $40/kg material, a 20% waste rate adds $10 to every $40 of material purchased. Nesting optimization software for flat pattern cutting typically reduces waste by 5-8 percentage points, paying back in material cost on medium-volume programs.

Cure cycle energy cost is a major driver for autoclave processes. A large autoclave (5m diameter x 10m length) at 180C cure temperature uses 150-300 kW during heat-up and 50-80 kW during soak. A 3-hour total cycle at 200 kW average: energy cost = 200 x 3 x $0.10 = $60 per cycle. Dividing this over more parts per load directly reduces cost per part. Running autoclave at 50% load versus 90% load doubles the energy cost per part. Autoclave scheduling discipline (full loads only) is often the fastest cost reduction available to composite shops.

Published 2026-05-28.