Barrel Glue Eccentricity & Die Head Offset Adjustment Operating Guide

In PE EXTURUSIONN BLOW MOLDING MACHINE production, barrel glue eccentricity and die head glue offset are common abnormal issues. They directly cause uneven glue thickness, defective product appearance, dimensional deviations and other problems. There are no fixed parameter values for troubleshooting; the adjustment relies mainly on operational experience and fine-tuning. The standardized adjustment procedures are as follows:

1. Core Adjustment Principle

The offset of molten glue follows a definite rule: if the glue deflects to one side or presents uneven thickness on one side, loosen the screws on the deflected side and tighten the screws on the opposite side. Fine-tuning the tightness of the die head fastening screws corrects the coaxiality between the barrel and the die head, balances the glue outflow speed in all directions, and eliminates glue eccentricity.

2. Step-by-Step Operating Procedures

Step 1: Locate the Glue Offset Position

Perform low-speed inching glue test on the equipment. Observe the barrel glue outflow status to accurately identify the deflection direction, thickness difference and bending direction of the molten glue. Confirm the exact offset position to avoid blind screw adjustment.

Step 2: Targeted Fine-Tuning of Die Head Screws

After confirming the offset direction, follow the principle of “loosen the offset side, tighten the opposite side”. Slowly loosen the screws on the side where the glue deflects, and appropriately tighten the screws on the opposite side. Always make minor adjustments instead of large one-time movements which may worsen the offset. Observe the glue outflow changes continuously during operation.

Step 3: Calibrate Glue Uniformity by Operational Feel

During screw fine-tuning, monitor and compare the glue outflow speed from all directions of the barrel and observe the glue shape. Slightly loosen the screws on the side with bent, excessive or thicker glue outflow to gradually balance the outflow speed. Repeat fine-tuning and testing until the glue thickness is uniform, the outflow is straight without deflection, and the discharging speed is consistent in all directions. This is the core adjustment step, which depends entirely on the engineer’s operational experience and precise micro-adjustment judgment.

Step 4: Stabilize Automatic Production

After the glue outflow becomes completely uniform and free of eccentricity and deflection, confirm the die head screw tightness is stable. Switch the equipment to automatic production mode and run a short trial operation. Monitor continuous discharging status to ensure no repeated offset or thickness fluctuation and stabilize production.

Step 5: Calibrate Finished Product Weight Parameters

After eliminating glue offset and eccentricity and stabilizing production, sample and test the finished product weight. Fine-tune the equipment parameters according to the standard product weight to correct weight deviations caused by screw adjustment and changed outflow status, so as to ensure qualified appearance, dimension and weight of final products.

3. Key Operation Precautions

1. All screw adjustments must be minor and gradual. Avoid excessive loosening or tightening, which may cause secondary abnormalities such as severe glue offset, glue leakage and overflow.

2. Always perform debugging in inching test mode. Adjust and observe simultaneously, with uniform and straight glue outflow as the qualification standard.

3. Operational feel and experience are critical. Repeated trial adjustments are required to match the fine-tuning range with the actual offset deviation and improve adjustment accuracy.