Extrusion Optimization for PA66 GF25

Extruding PA66 GF25 requires careful process engineering because the material contains 25% glass fiber, making it sensitive to shear, temperature control, and die design. Achieving optimal fiber distribution and maintaining dimensional accuracy are essential for producing high-quality thermal-break profiles. Proper process optimization ensures mechanical strength, stability, and long-term durability of the final product.

1. Melt Temperature Optimization

The melt temperature window of 265–290°C must be carefully maintained to prevent thermal degradation while ensuring complete melting of the polymer. If the temperature is too low, unmelted pellets and poor surface quality may occur. Excessive temperatures can degrade the polymer chain, reducing mechanical strength. Accurate heating zones and real-time monitoring help ensure consistent thermal conditions.

2. Screw Configuration and Fiber Preservation

Glass fibers are highly sensitive to shear forces inside the extruder. High shear shortens fibers, reducing stiffness and tensile strength. For this reason, screws with moderate compression ratios and gradual mixing elements are preferred. These designs preserve fiber length and allow uniform dispersion throughout the melt, leading to superior mechanical properties in the finished profile.

3. Die Design for Dimensional Accuracy

A well-engineered die eliminates dead zones, minimizes stagnation areas, and ensures uniform flow. Balanced die geometry improves fiber alignment and reduces internal stresses. Complex geometries such as multi-chamber polyamide bars require precision to maintain symmetry and prevent warpage.

4. Cooling and Calibration Control

Cooling has a major impact on final dimensional stability. Rapid cooling may induce internal stresses, while insufficient cooling can cause warpage and dimensional drift. Controlled cooling channels and precision calibration tables maintain the intended shape and size. Closed-loop puller systems ensure stable extrusion speed, preventing thickness variations and maintaining tight tolerances.

Conclusion

Optimized extrusion of PA66 GF25 requires precise control of temperature, screw design, die geometry, and cooling. By maintaining fiber length and achieving uniform distribution, manufacturers can produce thermal-break profiles with high stiffness, dimensional stability, and outstanding long-term performance. Robust process control ensures the reliability that modern architectural applications demand.