What is the Polyurethane Casting Process?

We rarely go through our daily lives without coming into contact with a polyurethane product. It is a very resilient product, thanks to the concise combination of various urethane polymers that add flexibility and strength to an almost limitless array of applications. A synthetic-based resin, polyurethane can be found in household products, such as adhesives, paints, and varnishes. In many cases, it can be used in place of sturdy yet inflexible materials, such as wood.

The influx of polyurethane into manufacturing has opened the doors to new potential applications for this powerful product. As the popularity of polyurethane increases, the polyurethane casting process continues to evolve towards becoming more efficient and less costly. When choosing a polyurethane product for your purposes, it is important to consider how it was cast. This will yield important data that will give you the insights and data needed to select the best product for your applications.

What Are the Advantages of Polyurethane Casting?

Polyurethane casting provides a handful of advantages including flexibility in design and production and reduced production costs. This can be especially beneficial when creating product prototypes or enhancing an already existing product without reinventing the wheel. The most common benefits of choosing polyurethane casting over-molding will catch the eye of engineers and project managers alike.

Some of the key advantages we have seen with polyurethane casting include:

✓  Rapid turnaround of molds ✓  Increased flexibility in the designing of master patterns ✓  Expanded pigment color selection ✓  Lower initial costs ✓  High-fidelity molding options for exquisite surface detailing

This shortlist of the advantages of polyurethane casting barely scratches the surface of what can be accomplished using this process. As exciting as these may sound, knowing these benefits is just a part of understanding how polyurethane casting works.

What Exactly is Polyurethane Casting?

To fully understand what polyurethane casting is, we need to break it down into a few parts. The overall versatility of polyurethane opens the doors into a wide range of casting options, many of which involve a molding process. This speaks volumes to the overall versatility using polyurethane, which is made possible in that it begins as a liquid before any casting or molding can take place. Being a liquid allows engineers to form polyurethane material into a variety of shapes and sizes.

Some of the most common methods of casting and molding include the following:

Blow molding	Polyurethane liquid is shaped with a small hole in one end. From here, air is blown through it, forcing it to match the contours and design of its mold.
Compression molding	The mold and compression material is heated before the pressure is applied to force the polyurethane to match the design of the mold.
Injection molding	This is the method primarily used for high volume manufacturing due to its scalability. Injection molding involves infusing polyurethane into a mold and curing it, and it is ideal for complex shapes and contours.
Polyurethane casting	On the surface, polyurethane casting is very similar to the process in injection molding. This involves having a mold filled with polyurethane and cured. The key difference is that this method is not suited for high volume production, due to the lower durability of the silicone molds used.

While these may show an overall dependence on molding in order to use polyurethane in robust or higher volume production, that is not at all the case. In fact, there is one form of casting that bridges the gap between reliance on molding and volume polyurethane casting.

How Vacuum Casting Revolutionizes Polyurethane-Based Production

Perhaps the most common casting process of polyurethane is vacuum casting. Also known as resin casting, vacuum casting is an adaptable form of production used to create parts for practical use. Using polyurethane and sometimes small plastics and cast nylon, this polyurethane casting process is used in cases where injection molding is not cost-effective, but when there is the need to show precision detail on a product’s surface areas.

One important advantage of using vacuum casting as a polyurethane casting process is the range of casting polymers available. This presents a large field of options to build products with almost limitless combinations of hardness and texture, as well as game-changers such as color matching or transparent component casting. Having these options available presents engineers with options to match their ingenuity and design creativity.

The versatility that vacuum casting offers comes with cost-saving and efficiency building characteristics, especially when engineers are facing short turnaround times for prototypes or building master models. Overmolding can be used as well, allowing you to blend different types and hardness levels of plastic into a single project. This methodology of polyurethane casting can easily be implemented into any engineering workflow and will deliver consistency in your finished products.

Maximizing the Benefits of the Polyurethane Casting Process

The polyurethane production market is continuing to evolve at a rapid pace. Staying on top of emerging methodologies and production trends can quickly become overwhelming for an engineer with multiple projects on their plate. This is why it is important to seek out the expertise of a proven team of engineers that can guide you through all of the nuances around polyurethane casting processes.