Honeywell CS071AE User Manual

Description of Problem
Blisters
Thinning
TROUBLE-SHOOTING GUIDE
Possible Causes
• Excessive moisture.
• Heating sheet too hot.
• Heating sheet too fast.
• Uneven heating of the sheet.
• Heat sensitive material.
• Design of the part.
• Sheet too thin.
• Uneven sheet temperature.
• Forming technique.
• Bad plastic sheet. Melt
index of sheet may be low.
Possible Corrective Action
• Pre-dry sheet at the temperature
required for the material you are
forming.
• Heat sheet very slowly to forming
temperature.
• Protect sheet from moisture before
using.
• Cut down sheet forming
temperature. You may be boiling
the stabilizers out of the material.
• Lower element temperatures.
Generally speaking, element
temperatures should not exceed
950° F.
• Increase the distance between the
heating elements and the sheet.
• Check forming oven for elements
that are overheating.
• Screen out hot spots.
• Check with plastic supplier on
temperature parameters for the
material involved.
• The overall draw ratio of the part is
too great for the starting thickness
of the sheet.
• The part has specific areas on it
that exceed the draw ratios of the
rest of the part.
• Increase the gauge thickness of the
plastic sheet.
• Check for air drafts in the forming
oven.
• Check for hot spots in the forming
oven. May have defective heating
elements.
• Check the sheet for a variation in
thickness.
• Consider where the part is thinning
and what forming technique would
best address this problem.
• Have physical properties of the
sheet analyzed.
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