Want to know more about designing with plastics? Bayer
MaterialScience engineers can help. They recently distilled their
collective knowledge about plastic part and mold design into a free
guide available both on the web and on paper.
At 175-pages, the guide covers nearly everything you need to know about designing and manufacturing a plastic part. To make materials selection easier, it starts off with guidelines for determining a plastic part's performance requirements. Topics here include mechanical loading,
temperature effects, chemical exposure, electrical properties,
dimensional tolerances, agency ratings, and more.
After sections on manufacturing methods and cost reduction, the guide
goes on to cover part design fundamentals—topics such as wall thickness requirements, ribs, draft angles, corners, radii, undercuts, molded-in threads, and holes. Next come sections covering structural design, design for assembly, machining, finishing, painting, and plating. The guide continues with a chapter on mold design.
Two of these sections really stand out. “The sections on structural
design and mold design contain information that you rarely, if ever, run
across elsewhere,” says Mark Yeager, the guide’s primary author and a
principal design engineer at Bayer MaterialScience. The structural
design section, for instance, offers clear guidance on designing around
creep. And the mold design segment provides detailed instructions on the sizing and location of gates and runners. It also explains the potential
part defects that result from gate and runner mistakes. “We put a lot of
meat in the mold design,” Yeager notes.
Finally, the guide concludes with a handy part-design checklist. Just
one page long, it can help you quickly review the key design tasks
required for a successful plastic part. Yeager notes that this checklist
was originally developed for Bayer’s own design engineers to use as they evaluated customer designs. “The last thing we want to do would be
forget something,” he says.
Much of the content in the guide isn’t brand new, but it has been hard
to come by in the past. Until recently, Bayer used the information
internally and distributed it to select customers. And the guide didn’t
appear on any public web site. Now, any engineer who wants it can get
it. Just go to www.designguide.bayerplastics.com. After a quick registration process—one without any password to remember—you can view or download the entire guide in PDF format. A hard copy will also be mailed to you automatically.