Experimental and Simulative Analysis of the Pressure Development in a Closed Injection Pultrusion Process with...

Area of Science:

• Materials Science
• Chemical Engineering
• Composite Manufacturing

Background:

• Traditional open bath fiber impregnation is insufficient for highly reactive resin systems with short pot lives.
• Innovative higher-performance resin systems necessitate advancements in pultrusion processes.
• Closed resin-injection pultrusion (CIP) offers a solution for enhanced fiber impregnation.

Purpose of the Study:

• To investigate the influence of key parameters on closed resin-injection pultrusion (CIP) process pressures.
• To validate a new simulation model for predicting pressure development in CIP systems.
• To enhance understanding of resin flow and impregnation within the pultrusion die.

Main Methods:

• Development of a closed injection and impregnation chamber ('ii-chamber').
• Systematic variation of resin viscosity, opening angle, and opening factor at the injection point.
• Conducting pultrusion trials and measuring process pressures within the ii-chamber and die.
• Utilizing a modified Darcy's law-based simulation model incorporating fiber movement.

Main Results:

• Resin viscosity demonstrated the highest sensitivity to pressure development among the investigated parameters.
• Process pressures increase across the length of the pultrusion die system.
• Experimental data validated the newly developed simulation model's predictive capabilities.

Conclusions:

• The flexible ii-chamber and die concept improve understanding of die system processes.
• CIP is a viable method for impregnating high-performance reactive resins.
• Accurate process monitoring and simulation are essential for optimizing pultrusion of advanced composites.