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. In the past, aluminum tooling was stereotyped 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 durable aluminum tools that are able to produce quality parts for low-volume production.
For engineers and project managers, it's a simple equation. Aluminum tools can be cut quicker, so products get to market faster, resulting in a higher return on investment and bigger profits.
How fast can aluminum tools be built? Consider this: Omega Plastics Inc., a rapid cut tooling maker in Mount Clemens, Mich., recently assisted a customer that needed parts unusually fast. After reviewing the options, Omega decided on aluminum tooling.
It 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 common as engineers and buyers face greater pressures to get tooling and 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 mold size. 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 tool in aluminum. Once on line, aluminum molds cycle about 35 percent faster than steel (assuming 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. Taking advantage of aluminum tools' faster build times, project managers find they can initiate testing or enter the market with parts off of aluminum while steel production tools are being built.
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.
But in most other cases, QC-7 aluminum offers 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.