Polyurethane Moulding vs. Injection Moulding: Which Is Better And Why?

Between polyurethane moulding and injection moulding, it is impossible to label one as the best and the other inferior. But if you absolutely have to choose, do so based on the use case. For instance, if the volume is low and the design complex, then go for polyurethane moulding. On the other hand, if the volume is high and the design is relatively simple, then go for injection moulding. 

Polyurethane moulding lowers tooling costs and ensures the products made using this process are of superior quality and impressive design. On the other side, when the goal is the amalgamation of both unit speed and volume, injection moulding takes the proverbial cake.

What’s The True Cost Of Bringing Ideas To Life?

When a company is about to launch a new product or a new iteration of an existing, top-selling product, the biggest financial hurdle on this path is tooling.

Injection Moulding

For the uninitiated, traditional injection moulding demands precision-designed, heavy-duty aluminium or steel moulds that retain their structural integrity despite repeated exposure to extreme pressure. Which is why, when a company wants to use injection moulding, the decision entails a significant upfront capital investment before a single part has even been designed and put into the market. 

And when launched, if the product has a design, structural, or functional flaw, the company would have to spend a lot of money again, as modifying steel or aluminium moulds is excruciatingly expensive.

Polyurethane Moulding

In contrast, the low-pressure polyurethane moulding process used in Reaction Injection Moulding is relatively easy on company owners' pockets, as polyurethane flows readily into the moulds under minimal pressure.

As the moulds don’t have to face excessive pressure, they can be fabricated using cost-effective materials. This, in turn, leaves company owners with slashed initial tooling costs, up to 80% lower than the cost of injection moulding tooling. 

Thus, if the company in question is a start-up or a lone product designer, one can breathe easy and confidently fabricate multiple prototypes to capture untapped market segments without emptying their coffers.

Injection-moulded products come out notoriously rigid. Additionally, this is not the right process when the product to be fabricated has varying wall thicknesses. Under high pressure, injection moulding results in end-products with warping, ugly sink marks, and invisible internal stresses that together compromise the product’s integrity.

Polyurethane moulding, on the other hand, doesn’t have the above constraints. And as the process takes place under low temperature and pressure, one can fabricate products with varying wall thicknesses. The resulting product will be free from sink marks, warping, and structural weaknesses. 

In short, with polyurethane moulding, one has the creative freedom to fabricate complex enclosures with thick ribs and varying contours.

Finding the Volume Sweet Spot

In terms of volume, one process fares better than the other, as shown in the sections below.

Injection Moulding Is Ideal When 

The goal is to fabricate 10,000+ units that will automatically amortise that steep upfront tooling cost.

Polyurethane Moulding Is Ideal When

The goal is to fabricate 20 to 1,500 units per year, as the return on investment will outweigh the tooling costs.

Making the Right Choice for Your Bottom Line

In the end, when you have to choose between injection moulding and polyurethane moulding, base your decision on your goals, such as volume, budget, and creative vision. With that stated and out of the way, if you need high-quality polyurethane products designed and manufactured, connect with Beechcraft Ltd. To learn more, connect with the company at your earliest convenience.