A flexible biaxially oriented multilayer film includes at least one layer having a thickness of at least about 0.5 mil and consisting essentially of an aromatic polyurethane, the film having been subjected to a biaxial stretching in the range of from about 12 to about 18, preferably about 16.
A layer of polyethylene or polyvinal chloride bonded to a layer of polyurethane material in turn bonded to a surface of material such as concrete or metal comprises a combination of a coating and a liner which prevents corrosion of the coated, lined material and is substantially free of pin hole penetrations. A method of spray applying atomized polyurethane material to a surface to be coated, such as concrete or metal, and thereover applying a layer of polyethylene or polyvinal chloride material is described. A machine for spray applying polyurethane material from a nozzle atomizes the polyurethane material at elevated pressures and temperatures.
A heat-shrinkable multilayer film suitable for use in fabricating bags for packaging primal and subprimal meat cuts. The multilayer film has a first outer layer of an ethylene-vinyl acetate copolymer, a first core layer of an oxygen barrier material, a second core layer of a polyurethane, and a second outer layer of a linear low density polyethylene. The multilayer film is preferably made by coextrusion of the layers, and then it is biaxially stretched. After biaxial stretching, the multilayer film is preferably irradiated to a dosage level of between 3 megarads and 8 megarads, and is then heat-sealed in the form of a bag. The bag has improved toughness properties.
Disclosed herein is a heat-resistant laminate film comprising a gas-barrier layer of a copolymer of vinylidene chloride and at least one comonomer copolymerizable with vinylidene chloride, outer layers of polypropylene and two adhesive layers of polyolefin modified by acid and thermoplastic polyurethane, disposed between any of the above layers and bonded with each other, the modified polyolefin adhesive layer being bonded to the outer layer and the thermoplastic polyurethane adhesive layer being bonded to the gas-barrier layer.
A flexible biaxially stretched multilayer film including a layer having a thickness of at least about 0.5 mil and comprising a blend of a polyurethane polymer and an ethylene vinyl acetate copolymer, wherein the weight fraction of ethylene vinyl acetate copolymer in the blend does not exceed 0.40, the film having been subjected to a biaxial stretching in the range of from about 12 to about 20.
A multilayer film generally includes a first exterior layer of polyurethane and a second exterior layer which can be formed from polyurethane, a homopolymer or copolymer of polypropylene, a blend of homopolymer or copolymer of polypropylene and elastomer, high density polyethylene, or mixtures of the foregoing. Such multilayer film is highly flexible and is advantageously used for various medical applications, such as the production of flexible pouches for the packaging and administration of medical solutions, drainage pouches, compression devices, and thermal blankets.
