Thermoplastic Polyurethane Films
Properties
Thermoplastic polyurethane, also referred to as PU or TPU, is a thermoplastic that possesses the durability of rubber. It can be processed by most common melt-processing methods including extrusion, blow molding, and injection molding. Films made of this plastic possess properties and characteristics that are superior to most polyolefinic films. This thermoplastic is often an excellent choice for more demanding flexible film applications because it is inherently strong, very flexible and tough, and unlike vinyl, it is free of plasticizers and thus won't become brittle or lose performance over time. TPU film also exhibits excellent dynamic flex performance, abrasion resistance, and tear strength.
TPUs have excellent resistance to grease and pure mineral oils such as lubricants and fuel, and exhibit outstanding resistance to hydrolysis. In particular, polyether-based grades will not undergo any noticeable decomposition when exposed to hot steam and the mechanical properties are nearly unchanged whereas ester-based grades can be somewhat susceptible to hydrolysis at elevated temperatures. The polyether-based TPU's also exhibit excellent resistance to microbiological attack whereas ester-based grades can withstand higher temperatures.
TPUs are easy to work with, and can be easily modified to suit a particular application through the addition of fillers, dyes, lubricants, stabilizers, and other additives.
Applications
TPU films, laminates and coatings are well suited for many demanding industrial applications including water-resistant textile laminates (wet suits, sails and sport goods), waterproof inflatables and bladders, automotive protection films, decorative wallcovering and furniture fabric laminates, shower curtains and tape backings (fabric bonding). Due to the low odor, high chemical resistance and inertness, many TPU grades are suitable for food applications under FDA regulations. TPU also finds many medical uses including blood plasma bags, hospital gowns, isolation fabrics, bio-medical devices and protective coatings for hospital beds.
TPU films can be used over a wide range of temperatures. For example, common ester-based grades can withstand temperatures up to 130°C, whereas many ether-based grades can withstand temperatures up to 90°C.
TPU films are sold in various types, thicknesses, and widths with properties tailored to meet specific requirements of particular end uses.