Designing cast urethane parts can be a complex and overwhelming process.
In order to ensure smooth sailing when heading into this process, there are a few things you'll want to consider before sending off your design to be manufactured.
Edges
The process of rounding out the edges or corners of your product is called radii. It's a necessary component of urethane casting because it improves the overall quality of the part as well as its load-bearing capacity.
Wall size
Your urethane part should be the same thickness throughout. If it's not, it can crack, warp, sink, or fail during the cooling process. For small cast urethane parts, 0.5mm is the recommended wall thickness. Larger cast urethane parts should typically have a wall thickness of 1mm.
Shrinkage
Shrinkage should be addressed before starting the manufacturing process. It's normal to expect at least 0.15% shrinkage, so be sure to account for this when designing your part.
Shrinkage may become problematic when there are inconsistencies in peak exotherm of the urethane, mold material, wall thickness, temperature, and casting size.
Logos and letters
Thinking about adding your logo or specific lettering onto your product? Make sure you nail down the specifics, including whether you want it to be raised or recessed. The height, width, radii, and depth of your casting will all need to be determined.
When adding logos and letters to your mold, here are a few things to note:
The width should be double the height
The letters will read more accurately with a larger radius
Features should be spaced at a minimum of 0.050"
By keeping this in mind before sending off your design to a urethane manufacturer, you'll save quite a bit of time, money, and resources.
Accessibility
As obvious as it sounds, accessibility is often overlooked when casting urethane products. Make sure you understand how the casting process works and familiarize yourself with common problems that may come up.
You'll need to ensure that your design is physically possible to execute by consulting with your manufacturer and other professionals in the industry. This will save you time and money in the long run and build a better relationship between you and the manufacturer. After all, the last thing you need is to waste your precious time and resources designing a urethane part that isn't possible to build.
At Mark Tool & Rubber, we work very hard to ensure top quality, durable products that are cost-effective with a quick turnaround time. We are proud manufacturers of both rubber and urethane products. Request a quote from us today to get started creating your custom parts!