Polyurethane products have many uses. Over three quarters of the global consumption of polyurethane products is in the form of foams, with flexible and rigid types being roughly equal in market size. In both cases, the foam is usually behind other materials: flexible foams are behind upholstery fabrics in commercial and domestic furniture; rigid foams are between metal, or plastic walls/sheets of most refrigerators and freezers, or other surface materials in the case of thermal insulation panels in the construction sector. Its use in garments is growing: for example, in lining the cups of brassieres. Polyurethane is also used for moldings which include door frames, columns, balusters, window headers, pediments, medallions and rosettes.

Polyurethane formulations cover an extremely wide range of stiffness, hardness, and densities. These materials include:

Low-density flexible foam used in upholstery, bedding, automotive and truck seating, and novel inorganic plant substrates for roof or wall gardens Low density elastomers used in footwear Hard solid plastics used as electronic instrument bezels and structural parts Flexible plastics used as straps and bands Cast and injection molded components for various markets – i.e., agriculture, military, automotive, industrial, etc.

Polyurethane foam is widely used in high resiliency flexible foam seating, rigid foam insulation panels, microcellular foam seals and gaskets, durable elastomeric wheels and tires, automotive suspension bushings, electrical potting compounds, seals, gaskets, carpet underlay, and hard plastic parts (such as for electronic instruments).

Usage per application

The following table shows an example how polyurethanes were used in one country over a dozen years ago (US data from 2004):

Application Usage (millions of pounds) Proportion of total Building & construction 1,459 26.8% Transportation 1,298 23.9% Furniture & bedding 1,127 20.6% Appliances 278 5.1% Packaging 251 4.6% Textiles, fibers & apparel 181 3.3% Machinery & foundry 178 3.3% Electronics 75 1.4% Footwear 39 0.7% Other uses 558 10.2% Total 5,444 100.0%

Cleaning products

Open-cell flexible polyurethane foam is used to make many kitchen and bathroom sponges. The combination of low cost, high flexibility and high abrasion and tear resistance make polyurethanes excellent materials for scrubbing applications. Polyurethane sponges have been shown to reduce the risk of spreading certain bacteria.

Industrial Insulation

Rigid polyurethane foam is used in various industries to provide thermal insulation to installations and pipes. In particular, the piping for district heating systems in Europe is primarily insulated using a pre-insulated pipes sandwich assembly composed of a steel heat service pipe, an insulating layer (polyurethane foam) and a polyethylene (PE) casing, which are bonded by the insulating material. One of the main advantages of rigid polyurethane foam is that it offers a very low thermal conductivity (with values as low as 23mW/m⋅K) while offering enough structural strength to withstand the loads that buried pipe systems are subjected to.

Due to the closed-cell nature of rigid polyurethane foams, PUR insulation has minimal water absorption, which coupled with an appropriate cover, makes it a particularly suitable in applications where bacterial growth is a concern. Polyurethane insulation is suitable for insulating pipes with surface temperatures ranging from -196°C to 148°C.

Furniture

Open cell flexible polyurethane foam (FPF) is made by mixing polyols, diisocyanates, catalysts, auxiliary blowing agents and other additives and allowing the resulting foam to rise freely. Most FPF is manufactured using continuous processing technology and also can be produced in batches where relatively small blocks of foam are made in open-topped molds, boxes, or other suitable enclosurers. The foam is then cut to the desired shape and size for use in a variety of furniture and furnishings applications.

Applications for flexible polyurethane foam include upholstered furniture cushions, automotive seat cushions and interior trim, carpet cushion, and mattress padding and solid-core mattress cores.

Flexible polyurethane foam is a recyclable product.

Automobile seats Flexible and semi-flexible polyurethane foams are used extensively for interior components of automobiles, in seats, headrests, armrests, roof liners, dashboards and instrument panels.

Polyurethanes are also used to make automobile seats. The seat manufacturer has a mold for each seat model. The mold is a closeable "clamshell" sort of structure that will allow quick casting of the seat cushion, so-called molded flexible foam, which is then upholstered after removal from the mold.

It is possible to combine these two steps, so-called in-situ, foam-in-fabric or direct moulding. A complete, fully assembled seat cover is placed in the mold and held in place by vacuum drawn through small holes in the mold. Sometimes a thin pliable plastic film backing on the fabric is used to help the vacuum work more effectively. The metal seat frame is placed into the mold and the mold closed. At this point the mold contains what could be visualized as a "hollow seat", a seat fabric held in the correct position by the vacuum and containing a space with the metal frame in place.

Polyurethane chemicals are injected by a mixing head into the mold cavity. Then the mold is held at a preset reaction temperature until the chemical mixture has foamed, filled the mold, and formed a stable soft foam. The time required is two to three minutes, depending on the size of the seat and the precise formulation and operating conditions. Then the mold is usually opened slightly for a minute or two for an additional cure time, before the fully upholstered seat is removed.

Houses, sculptures, and decorations The walls and ceiling (not just the insulation) of the futuristic Xanadu House in Florida, USA, were built out of polyurethane foam. Domed ceilings and other odd shapes are easier to make with foam than with wood. Foam was used to build oddly shaped buildings, statues, and decorations in the Seuss Landing section of the Islands of Adventure (USA) theme park. Rigid foam manufacturers sell foam that replace wood in carved sign and 3D-topography industries. PU foam is also used as a thermal insulator in many houses.

Polyurethane resin is used as an aesthetic flooring material. Being seamless and water resistant, it is gaining interest for use in (modern) interiors, especially in Western Europe. Polyurethane is also used in some domestic and commercial capacities to waterproof areas that have leaks, such as shower leaks and balcony leaks.

Filling of spaces and cavities Two binary liquids, one of which is a polyurethane (either T6 or 16), when mixed and aerated, expand into a hard, space-filling aerosolid.

Construction sealants and firestopping

Approved polyurethane sealants (which is different from foam) are available in one, two and three part systems, and in cartridges, buckets or drums. Polyurethane sealants are used to fill gaps thereby preventing air and water leakage. They are also used in conjunction with inorganic insulation, such as rockwool or ceramic fibres, for firestopping. Firestops can thwart smoke and hose-stream passage. The Browns Ferry Nuclear Power Plant used flammable polyurethane foam as a firestop, which was accidentally ignited and caused a major fire.

Water vessels Polyurethane foam is widely used in the marine world in many applications:

Inflatable boats Some raft manufacturers use urethane for the construction of inflatable boats. AIRE uses urethane membrane material as an air-retentive bladder inside a PVC shell, whereas SOTAR uses urethane membrane materials as a coating on some boats. Maravia uses a liquid urethane material which is spray-coated over PVC to enhance air retention and increase abrasion resistance.

Surfboards Some surfboards are made with a rigid polyurethane core. A rigid foam blank is molded, shaped to specification, then covered with fiberglass cloth and polyester resin.

Rigid-hulled boats Some boat hulls have a rigid polyurethane foam core sandwiched between fiberglass skins. The foam provides strength, buoyancy, and sound deadening.

Boat decks and outdoor marine surface areas Some boat decks including U.S Navy and Pakistani fishing vessels use specialized polyurethane sealants to protect from constant moisture and harsh oceanic elements. As an example, Durabak-M26 uses a custom single-part polyurethane to prevent water seepage to unwanted areas.

Water tanks Some water tanks are insulated with polyurethane chemicals (polyol and isocyanates) to maintain water temperature for long periods of time.

Flexible plastics

Tennis grips Polyurethane has been used to make several Tennis Overgrips such as Yonex Super Grap, Wilson Pro Overgrip and many other grips. These grips are highly stretchable to ensure the grip wraps neatly around the racquet's handle.

Watch-band wrapping

Polyurethane is used as a black wrapping for timepiece bracelets over the main material which is generally stainless steel. It is used for comfort, style, and durability.

Textiles

A thin film of polyurethane finish is added to a polyester weave to create polyurethane laminate (PUL), which is used for its waterproof and windproof properties in outerwear, diapers, shower curtains, and so forth. PU is used in some cutting-edge swimsuits to provide buoyancy for competitive swimmers. There are restrictions as the buoyancy enhances swimming performance.

A still more popular use of polyurethane in textiles is in the form of spandex, also known as elastane or by DuPont's brand name Lycra. Polyurethane fibers in the form of spandex can stretch up to 600% and still return to their original shape. Spandex is spun with other fibers, such as cotton, nylon, or polyester, to create stretchable fibers essential for clothing for both sports and fashion.

Shoes Polyurethane can be used for shoes, such as slippers and flip-flops.

Varnish

Polyurethane materials are commonly formulated as paints and varnishes for finishing coats to protect or seal wood. This use results in a hard, abrasion-resistant, and durable coating that is popular for hardwood floors, but considered by some to be difficult or unsuitable for finishing furniture or other detailed pieces. Relative to oil or shellac varnishes, polyurethane varnish forms a harder film which tends to de-laminate if subjected to heat or shock, fracturing the film and leaving white patches. This tendency increases when it is applied over softer woods like pine. This is also in part due to polyurethane's lesser penetration into the wood. Various priming techniques are employed to overcome this problem, including the use of certain oil varnishes, specified "dewaxed" shellac, clear penetrating epoxy, or "oil-modified" polyurethane designed for the purpose. Polyurethane varnish may also lack the "hand-rubbed" lustre of drying oils such as linseed or tung oil; in contrast, however, it is capable of a much faster and higher "build" of film, accomplishing in two coats what may require many applications of oil. Polyurethane may also be applied over a straight oil finish, but because of the relatively slow curing time of oils, the presence of volatile byproducts of curing, and the need for extended exposure of the oil to oxygen, care must be taken that the oils are sufficiently cured to accept the polyurethane.