5 Benefits of Low-Pressure Cast Urethane Molding

Low-pressure cast urethane molding can be a great entry-level option for creators new to manufacturing. This process offers many benefits that make it ideal for prototyping and small run production. However, it’s not a perfect solution for every idea, so it’s wise to discuss all options with a partner specialized in a wide range of production methods.

Urethane molding requires some use of advanced technology like 3D printing, meaning access to a prototyping expert will be necessary. With the right partnerships, the benefits of this process can help get a project completed under budget and on time.

What Is Low-Pressure Cast Urethane Molding?

Urethane molding is a relatively simple process that uses a master pattern, typically developed with CNC technology or 3D printing. Liquid silicone is poured into a chamber designed around this pattern, which is then dried and cut open. Once complete, the creator is left with both a male and female mold part.

The “low pressure” component comes in the filling of the new mold. In a process that uses injection molding, the material for the part goes in at a high rate of speed. In low-pressure molding, the material is poured in. It’s placed in a heated chamber to set. Finally, a technician cleans up any scraps or pieces, and the part is complete. This process is one that provides a lot of benefits when it comes to prototyping, though it’s also used in small scale manufacturing. The relative simplicity and control delivered to the technician ensure durability, affordability, versatility, and precision.

5 Benefits of Cast Urethane Molding 

Some of the benefits of low-pressure cast urethane molding become clear once the creator understands the process. Here are just a few features that make it appealing:

1. Precision: Urethane molding can create incredibly detailed designs, with the male and female mold parts allowing for things like overlapping pieces, raised sections, and even embossed lettering.

2. Versatility: Both soft, flexible materials and more rigid parts can work in a urethane molding process. The wide variety of materials makes this ideal for prototyping, where several different components can be tested to find the best, most cost-effective option.

3. Durability: Adding ribs to a piece can significantly increase its strength – and this is an entirely possible option in urethane molding. By adding ribs, the creator can build a part much stronger than they would with other solutions like injection molding or stereolithography.

4. Suitable for prototyping: Using lower-cost silicone, it’s possible to make many different molds for testing of various designs. This allows for rapid testing and updates seen in an iterative product development process. When a flaw is discovered in one mold, it’s simple to make a new one to eliminate that incongruity and build on the success of prior parts.

5. Low-cost creation: Molds are affordable and easy to create, which keeps costs down once the process is in place. However, the machinery needed to develop these molds can be expensive, so a third-party partnership is necessary to control costs.

These are just some of the benefits found in urethane molding, though it’s important to remember no design process is perfect. There are some downsides that creators must consider before they choose this as a production path.

Some Downsides to Cast Urethane Molding

While there aren’t many downsides to the low pressure cast urethane molding process, it’s essential to be aware of them before using this as an option. One of the most evident is the time investment in building the mold. As this is a multi-step process, it doesn’t work as well for larger-scale manufacturing. That’s especially true when one considers the limited durability of the molds themselves. They will require replacement regularly, as continued use wears them down.

Most pieces will require trimming and finishing as the plastic can seep out through small gaps in the mold. While this isn’t a big deal during prototyping, it’s a full-time job for any mass manufacturing process that could seriously cut into the bottom line. The downsides of cast urethane molding make it unsuitable for mass manufacturing. For this, injection molding is ideal as it leverages metal molds and high-pressure filling processes that minimize the need for finishing.

It’s easiest to enjoy the benefits of low pressure cast urethane molding when applying it to a low-production or prototyping process. For mass manufacturing, other options like injection molding are best. Creators should consult with an experienced manufacturing partner who understands a wide range of methods. This way, they gain advice on whether urethane molding or some other process will be the best possible solution for their project.