A urethane molder is a company that specializes in using the molding process to manufacture urethane products. Urethane molding, or polyurethane molding, is an incredibly versatile process, and it is important to look carefully for the right urethane manufacturer that will make sure your requirements and specifications are met. Specialties can differ from company to company. Some manufacturers provide general molding services for a broad range of applications, while other companies are more specialized in their capabilities and the industries they serve. There is not a single, universal standard method of manufacturing a product, and companies can vary in levels of experience. Therefore, it is highly recommended that you find a urethane molder that is trusted and well-versed in the products and application you have in mind.
Foam is one of the most common types of urethane material, and urethane molders work with various types of polyurethane. These types include flexible polyurethane foam, used for the automotive, bedding, and furniture industries; rigid polyurethane foam, used to create an energy efficient and versatile insulation for homes and businesses; and thermoplastic polyurethane, which is very flexible and used for construction and footwear applications.
Molded polyurethane is recommended over other materials such as rubber, metal, or plastic. Polyurethane components outperform these other materials in terms of longevity. Polyurethane is incredibly durable and is highly resistant to harsh conditions such as solvents, chemicals, abrasion, and heat. Urethane products have high compression and load tolerances, and can vary in levels of hardness. Polyurethane can be soft as a sponge, tough as iron, or any level in between. It is also possible to add additional materials to the polyurethane during the molding process such as dyes or other chemicals that will aesthetically enhance the final product.
Urethane molders can make their products in several ways.
- Compression molding. Liquid polyurethane is poured into a mold, which is then placed inside a heated compression press. The machine uses pressure to ensure the material conforms to every detail of the mold.
- Open cast molding. Liquid polyurethane is poured into an open mold, or open cast, and is either placed on a heated table or inside an oven.
- Spin casting. Liquid urethane is poured into a mold as the mold rotates. The motion of the mold assists in removing any air that is trapped in the mold as the liquid urethane is poured.
- Low pressure injection molding. The closed mold is equipped with “bleed gates,” or ventilation outlets that allow the air to escape from the mold during the injection molding process.
The preparation stage is the step in the process that requires the most work and attention to detail. The development of a high quality product depends on the measures taken in the earliest stages. It is crucial to carefully decide on a urethane resin, as all resins differ from each other in some way and may react differently, especially during the mixing stage of the process. Some urethane molders offer prototyping services, and sometimes you will be able to tell the experience level of the company just by looking for imperfections in the prototype. The presence of air bubbles in the prototype model is one of the telltale signs of an inexperienced company, as air bubbles is a common problem that can be easily avoided during the molding process. One of the methods used to prevent air bubbles is the use of vibration to filter the material before it solidifies.
Although the manufacturing methods among urethane molders may differ, one of the commonalities that all urethane molders share is that everything they manufacture is required to adhere to a set of criteria established by the American Society for Testing and Materials (ASTM). There are numerous tests that can be performed on urethane products to ensure that they meet adequate performance requirements, which can all be found in detail on the ASTM’s official website.
Molded urethane products are used in numerous industries for numerous applications, and therefore, there is a countless selection for urethane products available. In order to save both time and money, it is highly recommended that you seek out a urethane molder with experience manufacturing products for your specific industry, or even better, your specific application. That way, you will be more likely to get the exact product you ask for the first time around, and the product will be free of any imperfections. An experienced urethane molder will work with you from the planning stages, and keep you informed of the steps involved in manufacturing your products.