Polyurethane and Polyurethane Foam

May 29th, 2010

A polyurethane (IUPAC abbreviation PUR, but commonly abbreviated PU) is any polymer consisting of a molecular chain of organic units bound together by urethane (carbamate) links.
Polyurethanes are 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, high performance adhesives and sealants, Spandex fibers, seals, gaskets, carpet underlay, and hard plastic parts (such as for electronic instruments).

Polyurethane products are commonly called “urethanes”.
They can be flexible or rigid, but have a low density. Flexible polyurethane foam is most often used in bedding and upholstery, while the more rigid variety is used for thermal insulation and in automobile dashboards.

Flexible polyurethane is made in blocks and then cut to its desired shape. This is the way in which furniture cushions are made, for instance. You will see more and more polyurethane foam replacing materials such as polyester fiber or steel springs. The polyester fiber does not recover nearly as well as the foam does after compression. Steel springs recover well, but they can become noisy as they get worn out. They also always require some form of cushioning between them and the user.

Besides the flexible and rigid types, semi-flexible PU foam also exists, and is extensively used in automobile interiors. Seats, armrests, and headrests are likely to be made from PU. In the case of seats, the polyurethane foam is formed in a mold, after which it is removed and upholstered.

Rigid polyurethane foam has many important applications in construction. Many odd and detailed shapes like sculptures and domed ceilings are far easier to make with foam than with wood. Some manufacturers sell a specialty rigid foam which is used to replace wood in carved signs and three-dimensional topography models. Additionally it is used as home insulation, rigid boat hulls, tennis racket grips, and even surfboards.

Polyurethane foam can even be made into a form that sprays easily after which it rapidly expands when drying. It is tailored to own many different physical properties, depending on the desired use. This form can be used as industrial insulation, and also as roofing material, being waterproof and long-lasting. It can be used on boats, ships, and floating docks. In higher-density forms, it is used to boost the structural strength of aircraft wings.

Spray polyurethane foam is just about the most versatile building material around the world. It is also environmentally friendly as it does not contain or radiate any chemicals that are unhealthy or harmful for the environment.

Having said that, you should always take when applying the foam, because the fumes which it does emit can be dangerous if used in a non-ventilated place.
quality. Even so, care must be taken when applying the foam, because the fumes that it does give off can be dangerous if not properly ventilated.