What is a Pultrusion Injection Machine?
2025-12-02 16:52:111. Definition and Core Function
The Pultrusion Injection Machineis the core equipment in the pultrusion process, designed for the continuous production of fiber-reinforced composite profiles. Acting as the "heart" of the production line, its primary function is to precisely inject liquid resin (such as polyurethane or epoxy) under pressure to thoroughly impregnate continuously pulled reinforcement fibers (like fiberglass or carbon fiber). This allows the material to cure in a heated die, ultimately producing high-strength, lightweight composite profiles with a constant cross-section.
In simple terms, it solves the fundamental problem of "how to perfectly, efficiently, and continuously combine resin with fibers."
2. Working Principle and Process
Fiber Guidance: Reinforcement fibers are drawn from creels and aligned.
Resin Injection & Impregnation: The core stage handled by the Pultrusion Injection Machine. The machine injects a precisely metered and mixed resin system under set pressure into a closed impregnation chamber, forcing the resin to penetrate the fiber bundle from the inside out for complete wet-out.
Pre-forming and De-aeration: Excess resin and air are preliminarily removed.
Heating and Curing: The impregnated fibers pass through a heated die where the resin cross-links and cures into shape.
Continuous Pulling and Cutting: A puller continuously draws the cured profile, which is then cut to length.
3. Two Main Types: Polyurethane (PU) vs. Epoxy Resin Injection Machine
Core configurations and technical focus differ based on the resin system used.
| Aspect | Polyurethane (PU) Injection Machine | Epoxy Resin Injection Machine |
|---|---|---|
| Process Core | Handles highly reactive PU two-component systems. | Handles relatively high-viscosity epoxy two-component systems. |
| Technical Focus | Rapid mixing and precise temperature control. Fast PU reaction requires minimal mix residence time and exact temperature control to prevent premature curing. | High pressure and uniform impregnation. Higher viscosity often necessitates greater injection pressure to ensure full wet-out of high-fiber-content systems. |
| Temperature Control | Critical. Components A & B typically require independent, precise temperature control (e.g., 25±1°C) to maintain consistent reactivity. | Important. Requires heating of resin and die to reduce viscosity and promote cure. |
| Resulting Profile Traits | High toughness, high impact resistance, excellent fatigue resistance, suitable for dynamic load structures. | High strength, high modulus, excellent corrosion resistance & dimensional stability, suitable for high-strength, corrosion-resistant structures. |
| Typical Applications | Wind turbine blade connectors, seismic retrofit structural profiles, lightweight transportation components. | High-performance solar mounting structures, electrical insulation components, aerospace secondary structures. |
4. Key Equipment Advantages
High-Precision Metering: Uses servo-driven gear or piston pumps to achieve mix ratio accuracy up to ±0.5%, ensuring consistent material properties.
Efficient Impregnation: Optimized injection chamber design and pressure control enable rapid, complete fiber wet-out, minimizing porosity.
Intelligent Control: Integrated PLC and HMI allow storage of multiple recipes and real-time monitoring of pressure, temperature, flow, and other key parameters for process stability.
Continuous & Efficient: Supports 7x24 continuous operation with adjustable line speeds (e.g., 0.5-4 m/min), far exceeding the productivity of batch processes like hand lay-up.
5. Primary Application Fields
New Energy: Solar panel mounting structures, wind turbine components, battery pack structural parts.
Infrastructure: Bridge railings, gratings, seismic reinforcement rebars, cable trays.
Transportation: Automotive lightweight profiles, rail transit interior and structural parts, UAV frames.
Electrical Industry: High-voltage insulating ladders, transformer structural components.
GOOGIO Machineryprovides pultrusion injection solutions that address both the reaction speed control needs of Polyurethane Injection Machinesand the high-pressure impregnation demands of Epoxy Resin Injection Machines. Through modular design adaptable to different resin processes, we help customers achieve stable and efficient production of high-performance composite profiles.