If you’re not familiar with moulding or hot casting polyurethane already, you’re in for some good news. Presumably, you work somewhere in manufacturing or with complex machinery that runs constantly. If you’re reading this, it’s most likely because you’re either in charge of keeping that machinery running or you want to procure some yourself and want to know how to keep it working optimally for as long as possible. Well, whether you’re in agriculture, food processing, mining, manufacturing, oil, or even 3d printing, you’ll want to know what this material is all about. Polyurethane moulding allows for so many applications it’s mind-boggling. Read More

How to Mould Polyurethane: What It Is, How It Works, and How It’s Made into Various Forms

Can you picture the world before plastics became widely used? Think of everything in your everyday life that contains or is contained by plastic. Think of every device you use that has plastic making up many of its essential components. Plastics have become so widely used and relied upon that we couldn’t manage the same level of technology and efficiency we have now without them. We could certainly substitute them for other materials, but it wouldn’t be anywhere near as efficient or reliable. That’s the potential that polyurethane moulding, a plastic itself, has. Polyurethane is a plastic polymer with the potential to replace wood, plaster, rubber, ceramic, and even steel in many applications for greater durability and efficiency.

We’ve actually been using polyurethane for nearly a century now. It’s not a new invention. The insulation in many refrigerators and freezers is made of the stuff. Polyurethane moulding, on the other hand, is much newer, and it’s still making its way into various industries that stand to benefit from its usage. Polyurethane stands out from other elastomeric polymers for its flexibility. Not only can it be applied more broadly, but it can also be made from a wider range of starting materials. Most importantly, it can be moulded using several different techniques depending on the sort of shape and texture you need.

So How Do You Mould Polyurethane?

The moulding methods vary according to your needs. Do you want the end result to be flexible or rigid? Are you looking for a product that’s opaque or one that’s clear? Is the shape you’re creating simple, complex, or somewhere in between? Most moulding methods can get results regardless, but each one does a particular job best.

Open cast PU moulding is the most standard and common method. Here, liquid polyurethane is carefully poured into a mould either from above or below. A catalyst is also used to help solidify the polyurethane after it’s been shaped. Both the liquid polyurethane and the mould itself are heated to help the process go smoothly. Open cast moulding is ideal for producing larger or simpler shapes in a respectable volume. The mould itself is traditionally made of silicone, but there are variations. It’s critical that the mould be made of a hydrophobic material to completely eliminate any moisture that might ruin the process.

For shapes that have intricate details, such as cornices or prototype models, there’s centrifugal moulding. Here, the mould is quickly spun in one direction. As the liquid resin is poured in, the centrifugal force pushes it to the edges of the mould. Meanwhile, any air remains in the centre or in spaces away from the resin itself. Intricate details are usually an easy trap for air bubbles; this method helps separate the polyurethane from any trapped air.

For complex shapes that don’t have tiny details, you may want to use compression moulding. Here, hydraulic pressure keeps two halves of a mould tightly together. This ensures that the liquid polyurethane fills up every last tiny space in the mould, guaranteeing an even surface and proper distribution.

And for high-volume production and a quick process, many industries use injection moulding. Here, pellets of polyurethane are loaded into an injector. Inside the injector, a screw rotates at high velocity to create heat along the barrel, which melts the pellets before they reach the end. The heated resin is then injected at a very high velocity into a mould; the velocity both quickens the process and helps the polyurethane take the shape of the mould it’s in. We hope this comprehensive explanation on how to mould polyurethane helps you understand about this topic more. Read Less

The perfect partner for custom polyurethane products

For specific applications Richmond Wheel & Castor Co. can expertly manufacture polyurethane products in any hardness from 25A to 85D.

How does polyurethane compare to alternative material selections?


Compared to rubber Compared to metal Compared to injection moulded plastics
Superior abrasion resistance Abrasion resistance High impact resistance
Wide range or hardness for more application flexibility Non-corrosive Much lower tooling cost
Lighter load bearing Light weight Elastic memory
Cut and tear resistant Flexible Thick and thin section mouldings
Uv and ozone resistance Impact resistant Noise reduction
Lower cost tooling Nonconductive Lower and higher temperature range capable
Thicker sections possible Non sparking Resilience
Parts with very thick and thin sections possible Lower cost fabrication Elastic memory
Colourability Lower cost tooling compared to cast steel/iron parts Wide range or hardness for more application flexibility
Can be manufactured with a FRAS Rating (fire resistance & antistatic) Noise reduction in impact applications Abrasion resistance
Won’t damage other steel or concrete surfaces like steel components

What polyurethane products can we manufacture for your business?

Using precision engineering techniques and the latest equipment, Richmond Wheel & Castor Co can design and deliver any type of polyurethane product for your business needs! 

By utilising Richmond’s in-house moulding processes we can manufacture custom shapes, hardness variability and load bearing solutions, giving us a distinct advantage over traditional suppliers across Australia.

With nearly 10,000 products in our growing range, why not talk with our design and engineering team about our custom polyurethane product solutions?

Friendly Team of Experts

In-house Engineers

Cutting Edge Fabrication Facility

Fast Turnarounds

Affordable Solutions


Contact Our Team Today!

Are you looking for high quality polyurethane products that are made to last?

Contact our experts to discuss your requirements on 1300 474 246 or email [email protected]

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