Polyurethane laminate (PUL, thermal stretch, [1] fuzzy rubber [1] ) is a compound fabric made by laminating a cloth fabric to one or both sides of a thin film of polyurethane. [1] [2] Polyurethane laminated fabrics have a wide range of applications in medical, automotive and garment uses. [2]
Most PUL fabric is made by laminating lightweight polyester interlock knit fabric to a 1mm thick film of polyurethane. There are two processes used for lamination: solvent lamination, which fuses the fabric and polyurethane film into a single monolithic fabric, and hot melt, which uses heat-activated glue to adhere the fabrics together.[ citation needed ] Woven fabric and fleece fabric can also be used, [1] but a stiff fabric will drastically reduce the elasticity of the finished laminate.
PU laminate cloth is waterproof, breathes and stretches somewhat, and is soft and flexible. It can usually be machine-washed and dried, [1] and cleaned with dilute bleach or alcohol. [2]
PU fabric is useful as a wind and/or water barrier in the construction of fluid-splash protecting garments and outerwear clothing. [3] It is used for upholstery, especially in cars and restaurants. [2]
It is used in water sports clothing and equipment. [1] PUL is used for shower curtains, tents, and waterproofing backpacks. [3] [4]
Because it can be readily cleaned and sterilized, PUL is used for medical bedding, mattress protectors, reusable incontinence products, diapers/nappies, wet bags, and cloth menstrual pads. [3] [5] [6]
There are many different polyurethane blends and resin types, [7] which vary in durability, resistance to heat, ambient humidity, and light, [2] and the maximum temperature they will stand (some, for medical use, are autoclavable). [1] Resistance is measured by accelerated aging in a harsh controlled environment; the number of weeks survived is expressed as a hydrolysis resistance in units of years (expected under normal conditions). [8] Apart from heat and humidity, bleach, salt, and chlorine can also shorten coating life. [4]
If PUL is kept wet for a long time, it disintegrates into the water and sticks to itself, though it will probably go mouldy first. [8] If the polyurethane starts delaminating from the fabric, it may be possible to relaminate it with care and a hot iron. If the PU coating has decayed, it can be replaced. [9] [4]