After frequent appearances on home decorating TV shows, stainless steel refrigerators with French doors became the hottest item in home décor. Needing to meet this new market demand, appliance manufacturers scrambled to get new models into stores.
Among these was General Electric, one of the world’s largest appliance makers, who turned to 3-Dimensional Services Group for help in getting new GE products to market quickly. 3-Dimensional specializes in design, engineering and analysis, in-house tool construction and complete build of first-off prototype parts and low- to medium-volume production runs.
“GE had to move fast in order to get these new models into the stores to take advantage of this major sales opportunity,” says Steve Kelly, senior sales engineer for 3-Dimensional. “Our part in the process had to be done fast, and it had to be done right.”
The firm had to create the outer door panels for five new models of refrigerators in just eight weeks. Approximately 250 three-door sets (two French doors and a freezer door) were required for each of the five models. In addition, these five new models required that the doors be formed with smooth or textured, prepainted cold-rolled steel at thicknesses ranging from 0.024 to 0.032 inch.
The first challenge was to create the tooling for the four hydraulic presses, ranging from 400 to 1,600 tons, needed to make the new parts. Tooling was created with steel inserts and meticulously polished.
The parts had to be free of scratches or blemishes of any kind, says Mike Baranowski, program quality assurance manager. The reason is because GE wanted models available for consumer in-home testing, as well as in Home Depot as sales display models, before full production began.
To ensure optimum definition, the parts were protected with plastic sheeting during forming. After forming, parts were trimmed with dies and three- and five-axis lasers, then visually inspected. For dimensional accuracy, the parts were inspected with coordinate measuring machines (CMMs), which sampled data points every 100 millimeters.
Fixture inspection was also performed. Check fixtures were created quickly and accurately using a stereolithography system. The system has a laser beam that rapidly cures light-sensitive polymers into the desired shapes as soon as they are deposited. The check fixtures mirrored the plastic end caps that GE would fit to the tops of the doors. They had to fit precisely in order for the doors to open and close easily.
For more information on rapid prototyping, call 248-852-1333 or visit www.3dimensional.com.