Barrel temperature should be set 10°C above the melting point, typically 140-220°C depending on PE grade and melt flow rate. “PE shrinkage is anisotropic—higher in flow direction. Set it correctly, and you get glossy surfaces, proper dimensional stability, and consistent part quality. We've found that understanding PE's unique characteristics is. For most production applications, mold temperatures of 40–65°C balance crystallinity and shrinkage acceptably. Gate selection is particularly important for HDPE. Direct sprue gates are a common source of warpage — the high stress concentration at the gate, combined with HDPE's strong directional. Getting both into the correct range for the material is essential for all manufacturers, because injection moulding at the incorrect temperatures can have a significant impact on the final product, including the appearance and strength of the part. Plus, I'll share the insider tips that most manufacturers won't tell you.
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