How to Remove Mold Release Residue on Plastic Parts

eHow may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.

Things You'll Need

  • Rubber gloves

  • Mineral spirits

  • Wash cloths

  • Powdered laundry detergent

  • Running water

Injection molded plastics must be cleaned before they are safe to use.

You can quickly remove mold release residue from plastic parts without causing them any damage. Mold release spray is often applied to plastic injection molds to prevent sticking and control the uniformity of the product. These sprays leave an oily residue on the plastic pieces they form. This thin layer of mold release residue can be cleaned from a plastic surface with a few common household products. Once the oils have been completely removed the part is ready for paint or assembly.

Advertisement

Step 1

Put on rubber gloves and fold a wash cloth in half twice before pouring mineral spirits in the center of the cloth until a circle the size of a drink coaster is wet with solvent.

Video of the Day

Step 2

Sprinkle about a tablespoon of powdered laundry detergent onto the mineral spirit spot and squeeze the cloth closed to mix the two together.

Step 3

Open the cloth and rub all the surfaces of the plastic parts with the mineral spirit and detergent mixture.

Step 4

Fold the cloth to a new section and reapply the mineral spirit and detergent mix until you have cleaned away all the mold release residue. Feel the surface of the plastic to see if it still feels oily and slick.

Advertisement

Step 5

Rinse the plastic parts under running water once all the release residue is gone to wash off any soap powder and mineral spirits that remain. Dry the plastic parts completely with a new wash cloth.

Tip

Silicone mold release agents that are made specifically for thermoplastic injection forming are often designed to be easily removed with soap and mild solvents.

Advertisement

Video of the Day

references