Polyurethane foam is a plastic-based spray that expands to many times its original size. It's used in upholstery and bedding as well as for thermal installation in a variety of industrial projects. It is lightweight, resilient and resistant to mildew and other common allergens. Polyurethane foam can come in three different types: open-cell spray foam, which is highly resilient and flexible; closed cell spray foam, which is rigid and durable (like the kind used in wheels, tires, suspension bushings or installation panels) and microcellular foam, which creates tough elastomeric material (like the kind in car steering wheel coverings, headrests and other automotive interior pieces). Polyurethane is considered an excellent manufacturing agent because it is recyclable; much of the scrap is collected and reused, especially in the United States. Thus, spray polyurethane foam helps reduce solid waste and is considered environmentally friendly. However, polyurethane is flammable and can burn rapidly once ignited. Polyurethane Open Cell Spray Foam Polyurethane open cell spray foam is used in flexible foams. The flexibility results from critical processes used during the manufacture of the spray foam, since the softness can be severely compromised and if it's not made correctly. This kind of foam can be found in lots of common products, from upholstery fabrics to cushions. Some furniture and upholstery uses short-staple polyester fiber and cotton instead of polyurethane sprays, but both these substances are considered inferior because they do not retain their shape over time. Polyurethane Closed Cell Spray Foam Polyurethane closed cell spray foam is used in refrigerator walls and throughout the construction industry as thermal insulation; unlike polyethylene foam, it can last longer than 30 years, even when used in roofs (which are exposed to the harshest elements Mother Nature has to offer). Is it also resistant to both water damage and foot traffic. Polyurethane foam insulation can keep energy costs down, since it also prevents moisture infiltration and minimizes condensation. It resists heat movement and is reliable across a wide temperature range. Using low-density polyurethane closed cell spray foams can even reduce noise from outside the building, since it seals cracks and gaps. Source: industrial101
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