Comparative study of autoclave thermoforming and hot-press moulding for manufacturing green composite parts

The demand for sustainable and efficient manufacturing of lightweight polymer composite parts is driving the adoption of thermoplastic-based composites reinforced with natural fibres. This study explores two distinct manufacturing processes (autoclave thermoforming and hot-press moulding) to produce green composites from flax fibre woven fabric and polypropylene prepregs. The thermoforming process in autoclave offers precise pressure and temperature control, ensuring high-quality consolidation and fibre impregnation. Conversely, hot-press moulding allows for faster cycle times and increased production efficiency due to its direct compression approach. A comparative analysis of the two methods highlights differences in fibre-matrix adhesion, mechanical properties, and process repeatability. The results demonstrate that while both methods achieve high-performance eco-friendly composites, the choice of process can be optimized based on production rate and sustainability goals.