Are budgets a point of frustration between your purchasing and engineering departments? If so, you're not alone. Many manufacturers put pressure on their purchasing managers to cut costs as much as possible. This then puts product engineers in a difficult position when trying to find a reputable company to manufacture the parts for the product they're designing.
This is particularly true for parts that require expensive purchases throughout the product development cycle, like injection mold tooling for plastic prototypes. It can be tempting to go with cheap prototype tooling because it's "just a prototype mold", not the mold that will end up producing millions of parts. But a prototype is absolutely necessary to ensure your product will be manufactured appropriately without flaws. The purpose is to prevent you from spending tens of thousands of dollars on a production mold and then finding a fault in your design. Plenty of companies go the cheap route before they come to the conclusion that if they had spent just a little more upfront, they wouldn't have wasted thousands of dollars on tooling that they have to repurchase sooner than they otherwise would have.
Looking at purchases from a perspective of value rather than just looking at the initial price can help companies find a compromise that will make both departments happy. Costs almost always level out in the long run when quality and functionality are taken into consideration. So how do you determine the value of your tooling? Ask yourself these questions:
How many parts will the mold need to produce?
How abrasive is the material that is being molded?
Will the mold be constructed from aluminum or steel?
What type of mold maintenance does your supplier guarantee?
Is an initial sample quantity included in the price? How many?
There's no right or wrong answer here, only what makes sense for your project. Those answers, along with proper guidance from a molding professional, can help you determine what type of mold is worth investing in.
Here are some variables that affect the lifespan of an injection mold:
Tooling Material. Aluminum wears down faster than steel.
Resin selection. Filled materials, like glass filled nylon, will corrode a mold faster.
Mold Maintenance. Proper upkeep is imperative for a long lasting mold.
Supplier Quality. Your mold should be built properly in the first place.
If you only need a small amount of parts, don't need to use your exact material choice or otherwise don't need your prototype to be a replica of the part you're developing, long-term value won't matter as much. That is the appeal of rapid prototypes made with aluminum molds. Minimal investment for minimal return. But don't make the mistake of using these same services for your late stage prototypes.
If you need a higher quality, functional prototype that can be used to test your product, long-term value will matter more. Especially if you want to be able to use that same prototype mold for an initial production run. In this case, a steel mold is the better choice. If you go with a prototyping company that uses modular steel tooling, the cost difference between a mediocre prototype and a quality, functional prototype is minuscule.
You can take a chance and pay less upfront or you can pay more upfront knowing that by doing so, your company will save a lot more in the long term.
When it comes to your purchases, do you go by price or long-term value?