Press Release
RAPID PROTOTYPING PUTS A NEW FASCIA ON VEHICLES...FAST
Urgent Plastic Services' rapid prototyping technologies, specializing in plastic injection molding components, developed this mold, including insert construction for three versions of a rear fascia substrate, with a finished piece (top) and an 'as molded' part shown...delivering first off prototypes, from design to finished parts, in just four weeks.
When a leading Tier 1 supplier of automotive plastic components was asked for pull ahead tooling, they called on rapid prototyping shop for quick assistance
Plastech Engineered Products, Inc., headquartered in Dearborn, MI, and its dedicated staff have worked hard to become one of the premier automotive suppliers of production volume injection molded plastic components, including large body panels by offering quality, cost efficiencies, and responsive service to its global base of customers. Recently, that disciplined work ethic paid off with a contract to furnish the redesigned rear fascia plastic substrates to one vehicle builder for car models just two years out from reintroduction. The company was contracted to supply three versions of the rear fascia. The three styles include two domestic designs, one having two recesses for dual exhaust equipped cars, one allowing for only a single exhaust pipe, and the third version being for export with a single exhaust recess with an added port for tow hook access.
Plastech's automotive customer requested the fast turnaround of prototype parts, or those frequently referred to as 'pull ahead' tooling samples needed for fit, function and aesthetic reviews. The challenge...for injection molded plastic parts is that the tooling oftentimes can be expensive and time consuming, especially daunting for companies like Plastech, long accustomed to working with production tooling and high volume production systems, but not always having the resources for short run, fast prototype work.
Urgent Plastic Services (UPS), Rochester Hills, MI, has for nearly 10 years been servicing the needs of plastic injection molding companies with its unique capabilities, expertise, and technologies that have helped redefine prototyping with engineering and design, tool build and part deliveries that are up to 60 to 80% faster than conventional shops, and includes procedures that recognize the importance of incorporating manufacturing intent into the prototype process. The fascia project is just one case in point.
The process began when Plastech provided UPS with CAD files of the three styles of fascia panels. From the design workstations, the three-dimensional data files were downloaded to one of the firm's three stereolithography (SLA) rapid modeling systems. The SLA uses a laser beam path generated by CAD data to cure a light sensitive liquid polymer resin to a thin cross sectional form of the part. The process continues to cure successive layers until the entire part is formed.
The capacity of the SLAs, though possessing a large 20" x 20" x 24" work envelope, was unable to produce the panel, measuring approximately 73" x 16" x 18", 0.118" (1850mm L x 400mm H x 450mm D and 3mm thick) in a single piece, so three separate models were produced.
According to Ken Zalucki, sales engineer for UPS, this is where the company's extensive background and capabilities played a critical role. "We employ some of the most advanced laser processing centers available." says Mr. Zalucki, "Using these technologies, we laser cut and fabricated a highly precise fixture, a cradle if you will, that allowed our team to accurately assemble the three pieces and resin weld the individual polymer model components into a single, full size replica of the fascia."
The assembled model was then used by the UPS in-house pattern shop as a positive pattern to lay-up an engineered formula of epoxy to form the negative tooling that would be used to create the mold to produce the RIM prototype parts.
For some time now epoxy and many emerging variations have experienced expanding use for injection molds—and for about just as long, UPS has been a Beta test site for many such formula developments. Today, depending upon the prototype characteristics required, many blends in use could cure in minutes instead of hours and provide RIM quality strengths without the need to add reinforcing layers. These materials, when combined with SLA and other rapid modeling techniques, can make the transition from positive model to intermediate tool, if needed, to final epoxy tool ready for injection molding so prototype parts can be fabricated in hours or a few days as compared to weeks or months... and at costs substantially below investment in hard tooling. In addition, epoxy tooling for injection molding can incorporate the same design characteristics as would be required for production tools, thus the validity of the process and its manufacturing intent are simultaneously proven.
To make part removal from the mold easier, the UPS tooling design team added two inserts to the mold, used to form the two wrap around sides of the fascia. Also, interchangeable inserts that feature the different exhaust layouts and the tow hook port with different license plate lamp locations can be quickly changed out to make any of the three styles of fascia. And finally, because the fascia is so large, instead of using an injection molding machine, the UPS staff used free standing, low pressure RIM processing equipment with a gear driven pump to complete each shoot of the ‘parts-in-minute' polyurethane and silicone formula used to make the prototype components.
After removal from the mold, the pieces require only a simple manual trim of excess flash and pre-paint preparation. Mr. Zalucki explains that "the fascia substructure is one of the largest molded parts the company has produced, and it tested our capabilities and team work, from the design staff and engineers, to the SLA technicians and the mold crew. But it also demonstrates the viability of tooling such as the epoxy tools to be an economical and fast solution to mold prototype challenges."
Plus, for Plastech Engineered Products, the end result was first off prototypes, beginning from the design function to finished part, delivered in just four weeks, with five to six pieces per day produced afterwards. More importantly, it meant Plastech was able to deliver prototype parts to its automotive customer...ultimately helping to keep launch schedules on track, without surprises or unnecessary, costly delays.
UPS was established to meet the needs of the plastic parts manufacturing industry, and specializes in the rapid prototyping of injection-molded components. It is part of the 3-Dimensional Services Group along with Urgent Design & Manufacturing…the affiliation provides rapid prototyping of metal components fabricated through machining, stamping, laser cut and welded, and cast and molded in addition to the plastic injection molding process.
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