Palram PALSU - Manual (Page 35)

PALSUN® Technical Guide
35
Fault and Remedies in Thermoforming Practice
# Recognized Fault Probable Cause Proposed Treatment
Hot Line Bending Dr
ape
For
ming
Vacuum For
ming
Fr
ee
Blo
wn
1
Bubbles in sheet
Moisture content too high Pre-drying + + + +
2 Working temp. too high Decrease working temp. + + +
3
Hair fissures, fragile parts
Part overheated Decrease heating period + +
4 Mold under-heated Increase mold temp. +
5 Late extraction of part Diminish cooling cycle +
6 Vacum speed too high Reduce vacum rate +
7 Mold corners too sharp Round sharp corners +
8 Basic sheet size too small Increase sheet size +
9
Webbing
Erratic heating Prevent hot or cold spots +
10 Mold lead inadequate Check spacing-min. depth x 2 +
11 Vacum speed too high Reduce vacume rate +
12 Basic sheet size too large Clamp/mold spacing <50mm +
13
Blurred or partial detailing
Vacum too weak Seal leaks/add vacum holes +
14 Sheet rigid, under-heated Extend heating period or temp. +
15
Product sticks to mold
Mold overheated Decrease mold temperature +
16 Product release delayed Shorten release period +
17 Draft angle too steep Enlarge draft angle up to 4-6° +
18
Marked zones on product
Irregular finish of mold Treat mold to consistent finush +
19 Suction holes misplaced Install new, better placed holes +
20 Sheet overheated Decrease heating period/ temp. + +
21
Exterior flaws / roughness
Dirt/ grime on sheet / mold Wipe/Vacum-clean mold/sheet + +
22 Suction holes misplaced Install new, better placed holes +
23
Inconsistent shape of part
Mold/ brace under-heated Extend pre-heat of mold/brace +
24 Irregular heating/ cooling Prevent drafts, fix faulty heater + + + +
25 Product release delayed Shorten release period +