Polyurethane Molded Parts

Introduction to Polyurethane

Polyurethane is a type of polymer, which is a material made up of long chains of repeating molecules. It is a versatile plastic material that can be used in a wide range of applications, including foam insulation, upholstery, adhesives, and coatings.

Polyurethane is created by reacting diisocyanates with polyols, which are compounds that contain multiple hydroxyl groups. The resulting material can be molded into various shapes, or it can be foamed to create a lightweight, resilient material that is commonly used in furniture and mattresses.

Molding Polyurethane Parts

Polyurethane parts can be molded using a variety of techniques, including injection molding, reaction injection molding (RIM), and cast molding.

Injection molding is the most common method for producing polyurethane parts. In this process, the material is heated and injected into a mold cavity under high pressure. The mold tool is typically made of steel and is designed to produce the desired shape of the part. After the material has been injected, it is allowed to cool and solidify before the part is removed from the mold.

Reaction injection molding (RIM) is a similar process to injection molding, but it uses a chemical reaction between the polyurethane components to create the final part. The two components are combined in a mixing head and then injected into the mold. The chemical reaction causes the material to expand and fill the mold cavity, creating the final part.

Cast molding is a process in which the polyurethane material is poured into a mold and allowed to cure. This process is typically used for larger parts or parts that require a more complex shape. Once the polyurethane part has been molded, it may undergo additional processing steps such as hand trimming flash or surface finishing to achieve the desired final product.

Cryogenic Deflashing Polyurethane

Polyurethane parts can be cryogenically deflashed. Cryogenic deflashing is a batch process in which parts are exposed to cold temperatures using gaseous nitrogen. The nitrogen freezes the mold flashing on the surface of the part, making it brittle so that it can be easily removed. The parts are then tumbled and blasted with a polycarbonate media, to remove the flash.

Cryogenic deflashing is a popular method for removing flash from polyurethane parts because it is effective, does not damage the underlying part, or change the geometry. Want to send in your polyurethane part samples for a no-cost deflashing evaluation? Learn more by calling us at (508) 459-7447×105 or email us at info@nitrofreeze.com.