The edges of the foam are trimmed and compressed to ensure it retains a viable shape. The foam is comprised of an untold number of tiny gas bubbles trapped in the polyurethane. Unless the gas is released, the foam will take on the consistency of a rock. So, the foam passes beneath a series of heat lamps. It dries the foam and causes the bubbles to expand, then burst, leaving a completed spongy porous material behind.
Original Source. How Is Polyurethane Foam Made? Please fill out the following form to submit a Request for Quote to any of the following companies listed on. This article will give you a detailed insight into polyurethane foams. Read further to learn more about:. Polyurethane foam is a porous, cellular-structured, synthetic material made from the reaction of polyols and diisocyanates.
Its structure is a composite of a solid phase and a gas phase. The solid phase is made from polyurethane elastomer while the gas phase is air brought about by blowing agents. The huge gas phase of polyurethane foams ascribes desirable properties such as good thermal and acoustic insulation, high force absorption, low density, and flexibility. Polyurethane foams are sometimes referred to as foam rubber. Foam rubber is a broader type of material that include foams made from latex, neoprene, and silicone.
Polyurethane foams are used in the manufacturing of mattresses, furniture, car seats, thermal insulations, and packaging materials. The discovery of polyurethanes is attributed to Otto Bayer dated back in the year together with his coworkers at the laboratories of I. Farbenindustrie A. The first polyurethane was formed by the reaction between a diamine forming polyurea and an aliphatic diisocyanate.
The polyurea was later replaced by glycol due to the enhanced properties of the polyurethane created. The first patent for flexible polyurethane foam preparation was obtained by Zaunbrecher and Barth in The flexible polyurethane foam was done through simultaneous polyurethane synthesis and gas generation by combining organic toluene diisocyanate TDI , aliphatic polyester, water, and catalyst. In this one-step process, polyurethane was formed by the reaction of the isocyanates with the hydroxyl-functional groups from the polyester while its gas phase was formed by the generation of carbon dioxide.
Carbon is a product from the reaction of diisocyanates with water. This one-step process was highly exothermic and resulted in scorching and fires. This one-step process was then later transformed into a two-step process. This two-step process starts with the polymerization process prepolymer preparation followed by gas generation. Since then, polyether polyols became the major polyols in the polyurethane manufacturing industry. Initially, polyurethane foam production was done in a two-step process.
But with the development of catalysts and surfactants, this was then replaced by a one-step process. Further refining of blowing agents, polyether polyols, and polymeric isocyanates led to the advancement from flexible polyurethane foams to rigid polyurethane foams.
Because of this property, it is a preferred material in furniture, bedding, automotive seating, athletic equipment, packaging, footwear, and carpet cushion. It also plays a valuable role in soundproofing and filtration. In all, over 1. Foam is most commonly produced in large buns called slabstock, which are allowed to cure into a stable solid material and then cut and shaped into smaller pieces in a variety of sizes and configurations.
The slabstock production process is often compared to bread rising—liquid chemicals are poured onto a conveyor belt, and they immediately begin foaming and rise into a large bun typically about four feet high as they travel down the conveyor. A corousel of molds for making foam components. Raw materials for foam can also be poured into aluminum molds, where the cured foam assumes the size and shape of the mold.
Molding allows the production of foam items in shapes that are difficult to achieve fabricating foam from a slabstock bun. The molding process can consolidate foam components with other parts such as a metal frame. One example of thise is the headrest of a car seat. Because of the high upfront costs of producing molds, molding is typically reserved for high production runs. Molded foam is frequently found in auto interiors, business furniture and sports equipment.
The processes for producing slabstock and molded foam are covered in a PFA training tutorial on Foam Production. The basic raw materials for FPF are often complemented with additives that yield desired properties.
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