Because of increasing pressures in the product-development industry for high-quality parts delivered quickly and at a reasonable cost, more and more companies are now using aluminum tooling as a viable option for low-volume production runs.
This indicates a recent change in mind-set regarding aluminum tooling. In the past, physical characteristics and performance of aluminum alloys had stereotyped aluminum tooling as good enough only for prototypes. But higher-quality alloys developed in the early 1990s improved the strength, hardness and thermal conductivity of aluminum. The result is aluminum tools that have proved to be durable and able to produce quality parts for low-volume production uses.
For engineers and project managers, it´s a very simple equation. Aluminum tools can be cut quicker, and that means products can get to market faster. And the faster products are brought to market, the higher the return on investment and the bigger the profits.
How fast can aluminum tools be built? Consider this: Omega Plastics Inc., a rapid cut tooling facility in Mount Clemens, Mich., recently assisted a customer that needed parts unusually fast. After reviewing the list of options, Omega decided on aluminum tooling.
Omega gave the customer a quote over the phone on a Friday afternoon, received final computer-assisted-design data by 6:30 that evening, and had plastic parts in hand on Monday afternoon, said Omega project manager Todd Hutson.
Though the situation was an unusual one, Hutson said extremely quick turnaround times are becoming more and more common. Engineers and buyers are facing greater pressures to get not only tooling but quality parts as soon as possible.
Generally, aluminum tools can be built 25 percent faster than steel molds, with build speed increasing in proportion to the size of the mold. As a rule of thumb, if it takes six to nine weeks to make a hardened-steel tool, it can take as little as three to five weeks to deliver the same tool in aluminum. And, once on line, aluminum molds cycle about 35 percent faster than steel (assuming both have the same tool construction).
QC-7 aluminum tools are up to 30 percent less expensive than hardened-steel counterparts. This price difference can continue to grow if the product is still in the developmental stages and engineering changes are likely to be needed. Project managers are finding that it is more sensible to make the changes and bridge their high-volume production needs with aluminum tools before cutting steel production tools. Taking advantage of aluminum tools´ faster build times, they initiate testing or enter the market with parts off of aluminum tools while their steel production tools are being built.
Aluminum tools offer an attractive alternative to steel, but are they for everyone? It depends on the project. Steel remains the best choice in certain applications, such as where an A-1 surface finish is required, when mold temperature requirements exceed 350° F, or when millions of shots are required to fill the project´s needs.
In most other cases, QC-7 aluminum tools offer a viable option for low-volume production runs. For example, using a standard, low glass-filled resin on a part of moderate complexity, aluminum tooling typically produces more than 50,000 shots. Moving to the extremes of complexity and resin selection, aluminum tooling can produce more than 250,000 shots on the high end and fewer than 10,000 shots on the low end.
In addition to production-quality components, alumimum tools allow for faster turnarounds, quicker time to market, and often provide companies with a better return on investment.
Kaczperski is vice president of business development at Omega Plastics Inc. in Mount Clemens, Mich.