July 13

Hear from Custom Rubber and Urethane Experts

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How the Polyurethane Manufacturing Process Works

Polyurethane is a versatile material that has a variety of applications. It can be used for insulation, furniture, car parts, paints, adhesives, and more in various industries. 

Understanding how the polyurethane manufacturing process works, as well as how the raw materials are mixed and processed to create your desired products, will help you know what to expect when it comes time to order your custom polyurethane parts.

Understanding the process

When you start your polyurethane project with a trusted manufacturer, you'll first want to determine the specs of your product. There are endless design variables and combinations available so that you can create exactly what you need, whether that's a specific hardness, flame/abrasion/chemical resistance, strength, elasticity, or tear strength. Exact specifications are feasible as long as the right mixture is created.

Mixing ingredients

Diisocyanates are used to create various polyurethane products and are a very versatile group of building blocks. When they're mixed with other chemicals, they can create some of the most useful and important polyurethanes.

The unique properties of polyurethane along with the proportions of certain ingredients during the mixing process are what allow for custom features like hardness. 


There are four types of polyurethane molding: injection molding, compression molding, spin casting, and open cast molding.

Injection molding

Injection molding involves injecting liquid polyurethane into a semi-closed mold at a low pressure. Openings in the mold allow the air to escape slowly.

Compression molding

Compression molding also requires the polyurethane to be in liquid form. Once it’s poured into a mold, it’s placed into a compression press, where the heat will thicken the liquid and the pressure will finalize the molding process.

Spin casting

As the name implies, spin casting involves a spinning mold. The liquid polyurethane is poured into it while it's rotating to remove any trapped air.

Open cast molding

Open cast molding, like all other forms of molding, starts with liquid polyurethane, but is poured into an open mold that requires heat to finalize the product.

Quality assurance

Once the polyurethane has cooled after the molding process, it will be shaved down into your desired size. Shaving also allows for extra clean-up, giving you a flawless product that's consistently sized all the way around. 

After shaving, your polyurethane product will be packaged up and ready to go. When you choose an experienced manufacturer like Mark Tool, you can rest assured that your product went through a rigorous quality assurance process to ensure that you're getting exactly what you ordered. If you choose a custom product, we will also keep your mold to make the reordering process quick and easy.

Now that you know how the polyurethane manufacturing process works, you can confidently move forward with your project knowing that your parts will be made to your exact specifications. To get started, request a free quote from Mark Tool today!

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