Polyethylene Blow Molding
Trouble Shooting Reference Guide

Our years of experience in resin distribution benefit our customers in many ways. For one thing, there are few, if any situations that we haven't encountered at one time or another.

Below are some of the most common problems reported while blow molding polyethylene, along with recommendations for corrective actions. After you review the information, make sure to contact us for information on how your company can benefit from our plastin resin expertise.

PARISON SITUATIONS

SITUATION

CAUSE

SUGGESTIVE CORRECTIVE ACTION

Air Bubbles

Moisture in material, Cold material, Low fill pressure, Feed zone too hot

1.		Dry material
2.		Run material that is room temperature
3.		Increase fill pressure (slowly)

Stringing, Drooling

Fill pressure too high, High die temperature

1.		Decrease fill pressure (slowly)
2.		Turn die heater variacs off.

Sticking to die
or blow pins

Material or tooling too hot

1.		Reduce stock temperature.
2.		Check for correct pin alignment.
3.		Be sure die heater variacs are off after start-up.
4.		Check blow pin alignment.

Curling or
Sticking

Tooling mismatch, Temperature differential on the tooling

1.		Set proper bottle weight for the tooling design.
2.		Recut tooling for proper match
3.		Check temperature settings and heater band operations
4.		Increase pump pressure, check hydraulic system for intenal leakage.
5.		Reset fill pressure.