posted 02-12-2002 04:56 PM
I´d woulde like to understand the following: When I produced a HMW Polyethylene Sheet and submit it to a Thermoforming process( make a truck liner), the bottom of the liner is allways warpaged up. Is that concern with the head and die? Thank by your attention Demétrio Narciso
How much are you orienting your sheet? cut a strip, measure its lenght and width, heat an oven to 200C, place the strip you measured on a talc coated tray and give it 10 mins, remeasure the width and lenght- as a percentage, you shouldn't have more than 5-10% change in either direction.
Chill roll temps, haul off speed and die gap (set it 5-10% over desired gauge)are the variables to look at.
posted 02-12-2002 04:56 PM
