Reinforced PA6 Injection Parameters: A Ready-to-Use Processing Window

Drying — never skip it

80-90 °C for 4-6 hours in a dehumidifying dryer with dew point below -20 °C, targeting moisture below 0.05%. Material left open longer than 4 hours needs 1-2 hours re-drying.

Diagnostic tip: if extrudate shows bubbles or silver streaking along with unusually easy flow, dry further rather than lowering temperatures.

Temperatures and speeds

Suggested barrel profile from feed throat to nozzle: 240 / 255 / 265 / 270 °C with the nozzle at 265-275 °C. Never exceed 290 °C.

Mould at 70-90 °C: use the upper end for strength and heat resistance, the lower end for cycle time. Higher mould temperature also reduces fibre show on cosmetic parts.

Medium to high injection speed of 30-60 mm/s and back pressure of just 5-15 bar; more shears the fibre excessively.

Hold pressure and defect mapping

Set hold pressure at 40-60% of injection pressure and hold time to gate freeze-off, typically 3-8 seconds.

Sink marks → raise hold pressure or time. Warpage → check mould temperature uniformity and gate position. Fibre show → raise mould temperature and injection speed, reduce back pressure. Brittle failure → check moisture first, then thermal degradation.