Abstract: A multilayer protective film useful in insulated wall structures of appliances such as refrigerators, freezers, or boiler units, for example. The multilayer protective film has a substantially polyolefin protective layer. The multilayer protective film also has a substantially polyolefin surface capable of bonding to polyurethane foam without the use of an adhesive. The multilayer protective film bonds to and protects thermoplastic liners from attack by blowing agents used in the production of polyurethane foam. The multilayer protective film is also adaptable to be regrind-compatible into thermoplastic liners made of styrenic polymers.