TPE Pelletizing: Causes And Solutions for Melt Surging

During TPE (Thermoplastic Elastomer) pelletizing, melt surging refers to the abnormal and excessive outflow of molten material from the die or screw area during the extrusion process. This results in unstable and discontinuous material flow. The main symptoms include:

1.Unstable Material Flow: The melt becomes intermittent and uneven, losing its steady and continuous extrusion state.

2.Abnormal Output Rate: Compared to normal extrusion, melt surging significantly increases the output, resulting in overly thick or irregularly shaped strands.

3.Die Accumulation: Melt may accumulate near the die opening, forming uneven material layers or even causing die blockage.

4.Reduced Product Quality: Irregular and unstable strand shapes can negatively impact the quality and performance of the final product.

I. Causes of Melt Surging

1.Improper Temperature Control:

• Excessive Temperature: Overheating in the extruder can cause the TPE melt to become too fluid, increasing the risk of surging.

• Temperature Fluctuations: Inconsistent heating can alter melt flow characteristics, leading to unstable extrusion.

2.Excessive Screw Speed:

• High screw speeds accelerate melt conveyance, increasing pressure at the die and resulting in melt surging.

3.Unstable Raw Material Quality:

• High levels of impurities or moisture in the raw material can compromise melt stability and flow, contributing to surging issues.

II. Solutions to Melt Surging

1.Adjust Temperature Control: Maintain a stable and appropriate heating temperature in the extruder to ensure consistent melt flow and prevent surging.

2.Control Screw Speed: Adjust screw speed according to the flow characteristics of the TPE and extrusion requirements to keep die pressure within normal levels.

3.Inspect and Maintain the Die: Regularly check the die for flatness and clearance; replace worn components in a timely manner to maintain extrusion stability.

4.Ensure Stable Raw Material Quality: Use high-quality TPE with consistent properties. Check for moisture and impurities; dry the material if necessary and avoid over-lubrication.

5.Standardize Operations: Train and supervise operators to follow correct process parameters and equipment operation guidelines to ensure smooth production.

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