Removing Surface Protection Masking from Plastic
Usually removing the paper surface protection masking on plastic is easy. It is simply a matter of starting in a corner and rolling it off of the surface. Many manufacturers and fabricators recommend rolling the masking around a cardboard tube.
Over time the adhesive can build in adhesion to the surface of the plastic. A masked plastic sheet, which has been exposed to heat, can be extremely difficult to remove. If the masking is exposed to sunlight, the adhesive will crystallize and will be impossible to remove.
If the paper masking is difficult to remove, and comes off in little bits and pieces, try saturating the sheet in water. Some people recommend spraying the masking with a product such as Goo Gone. Allow the cleaner time to penetrate the paper and soften the adhesive. Do not allow the cleaner to dry.
After 20 to 30 minutes, try to peel the masking from the surface of the plastic. If the masking is still difficult to remove, resaturate the paper and allow more time for the cleaner to work. If any adhesive remains after the removal process, use RapidPrep or isopropyl alcohol (IPA) to clean the residue.
After removing the paper masking, clean the surface of the plastic sheet with a mild, non-abrasive detergent and water. Gently dry the surface of the plastic with a soft towel. Drying with minimal pressure will minimize the chance of scratching. Do not clean the sheet with solvents such a Acetone, Xylene or Toluene. These strong solvents subject the plastic to chemical stresses, which potentially could weaken or craze the sheet.