Applications

Polyurethanes are everywhere in our daily lives due to their variety of properties, including insulating ability and light weight. They can be solid or expanded, flexible, elastic, semi-rigid or rigid, and can take the form of foam slabs, molded articles, film or even fibers.

The key markets for polyurethanes are the appliance , construction, automotive, and furniture/mattress industries.

Construction

In the United States, construction has developed into the most important polyurethane market, followed by automotive and furniture. Polyisocyanurate insulation used in roofs and walls is very thermally efficient, which facilitates compliance with the codes of the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) and many local energy codes. Also, polyiscyanurate insulation uses blowing agents that are free of chlorofluorocarbons (CFCs). Texas A&M University has documented energy savings by using spray polyurethane foam (SPF) insulation, which can be applied to existing roofs, as well as walls, crevices, gaps, and holes. According to the institution's studies, energy savings can make up for the cost of application in three to four years.

In addition to spray polyurethane foam, light yet sturdy, high-quality construction materials such as metal-faced polyurethane foam sandwich panels are increasingly used for commercial buildings. These panels allow walls to be erected rapidly and economically. Another rapidly growing market section is laminated board stock, both for residential sheathing and commercial roof insulation. Some manufacturers are now using glass fiber skins to improve the strength properties of sheathing products.

Thermal insulation has become one of the most important fields of application in the building industry. Polyurethane foam insulation has excellent insulating properties, which are useful in applications that require minimal wallstock thickness at high insulating capacity. Another key application is pipe insulation for in-house usage or for insulation of oil or district heating pipes. Back to Top

Automotive

The automotive industry uses polyurethane materials in many applications, including body panels and trim, energy-absorbing foams, cavity-filling and sound-absorbing foams, lightweight seat foams, and coatings to protect the vehicle finish. In vehicle seats, polyurethane flexible foams are high-performance, elastic materials that can be molded in almost any form. They can easily be mass produced, and inserts for fastening upholstery materials can be foamed in place in the mold. Seats with increased stability at the sides are produced with dual-hardness foam technology.

Polyurethane foams can also provide protection. For example, special polyurethane foams are well established in the soundproofing market, whether for encapsulating the engine compartments of commercial vehicles, covering end walls or serving as backing to carpet in the passenger area.

Cavity-filling polyurethane foams are injected into the cavities of automobile frames to add rigidity to the frame without excessive weight. And instrument panels incorporate polyurethane foam beneath the surface skin, which often is also made of polyurethane. On the exterior, elastomeric polyurethane systems fix side windows in place on many minivans and SUVs, and are used as lightweight, corrosion resistant fenders, trim and side cladding.

Composite panels formed with polyurethane in conjunction with other materials are already widely used by the auto industry. Typical applications are door trim panels, sun shades and package shelves. These composite parts can be produced cost-efficiently in a wide variety of forms. They are the main rival to light metals in the automotive industry. In the U.S., interest is currently focused on glass fiber mat-reinforced door trim panels. Auto trim manufacturers can replace these mats with cut rovings that are applied directly to the mold along with the polyurethane to cut costs and handling of the glass fiber.

A recent trend in Europe is to use renewable, natural raw materials, such as natural fiber mats rather than glass fibers as the reinforcing material. The mats can be produced from flax or sisal, and they are initially sprayed with a polyurethane rigid foam component, then formed in compression molds and cured. The moldings are only about 1.8 mm thick – less than one-tenth of an inch. They are ideal as carriers for door trim panels because they are extremely light while having excellent rigidity. However, the development of press technology is even more far-reaching. Polyurethane can also be combined with a core made of paper or cardboard honeycomb in sandwich moldings. These moldings – produced in different thicknesses and distinguished by low weight – exhibit good dimensional stability and stiffness. Back to Top

Furniture/Mattress

During the last decade, soft and ultra-soft flexible slabstock polyurethane foams have found new application opportunities in the furniture and bedding industries. This has been driven by new furniture designs and changes in bedding construction that place more emphasis on comfort while demanding higher quality and increased durability. Flexible polyurethane slab and molded foams have a very broad range of applications, and are especially suitable for stylish, high-quality upholstered furniture. Polyurethane foams last longer and are more comfortable than conventional upholstery materials. In fact, polyurethane is now the most widely used upholstering material.

Polyurethane flexible foams for furniture and mattresses can be manufactured in any desired shape: either from continuously produced foam slabs by means of modern fabrication processes, or in one “shot” by filling molds which can incorporate connecting and supporting elements. This wide range of production options is particularly important, given the immense variety of designs found in modern furniture. Flexible foam promotes a wide spectrum of different characteristics and allows the development of new foam-based products with unique comfort behavior.

Another type of foam is viscoelastic slabstock polyurethane foam, which is also referred to as visco, slow recovery and memory foam. Viscoelastic polyurethane foam is characterized by a number of distinctive performance features. These include low resilience, shape conformance, vibration and sound damping, and energy and shock absorption. These unusual traits make viscoelastic foams of interest in many diverse applications, the largest of which include pillows and mattresses. Many different foam grades are produced commercially to meet the performance requirements of these applications. Bayer has developed special raw materials for viscoelastic foam production.  Back to Top

Appliance

Rigid polyurethane foams insulate and increase the energy efficiency of refrigerators, freezers, water heaters, vending machines and other appliances used in residential and commercial applications. With these polyurethane systems, Bayer has played a role in the replacement of chlorofluorocarbons (CFCs), which are harmful to the ozone layer, by using more environment-friendly materials.  Back to Top