This automated PreformCenter work cell designed and built by
Dieffenbacher GmbH (Eppingen, Germany) has the capability of
producing preforms at production-rate cycle time (less than
three minutes), using a cutting table, robot arm, binder
application module and draping module. The image below shows
a demonstration preform produced by the work cell.
Structural preform
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emerge from the shadows
compositesworld.com
Not yet in full production, with one
exception, all are aimed at accelerating
composite part manufacture at fast
automotive rates.
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reforms have been used for almost 80 years in infusion
molding processes. For most of that history, however,
the vast majority were made with chopped glass fbers
directed over perforated metal forms in vacuum-forming
processes — think molded transit bus seats, for example. More
recently, engineered preforms have been developed through the
use of automated knitting and weaving machinery. Tese twoand three-dimensional constructions are increasingly capable
of reinforcing high-performance structural composite parts, but
most have failed to enter the manufacturing mainstream in the
automotive industry due to their perceived high cost, the auto
industry's change-averse culture and some difcult-to-surmount
engineering hurdles.
During the past decade, however, more stringent fuel economy
and emissions standards have overcome automakers' resistance to
change. Many are developing structural composites in mass-produced vehicles for weight reduction on the strength of recently developed rapid infusion processes designed to meet high auto build rates.
Te good news is that equally fast, cost-efective and sophisticated
engineered preform technologies are being developed in parallel.
"Preforms can be created faster than metal can be stamped, on
the order of several seconds," asserts Dan Buckley, manager of research and development at American GFM Corp. (AGFM, Chesapeake, Va.). "And contrary to what many in the industry think, preforming can save money when creating parts," he continues. As a
new generation of engineers comes of age, its members are circling
back to the concept of assembling a complex part's continuous fber
reinforcements in a separate, automated process as a way to accelerate composite part processing — with the goal of meeting the auto
industry's part-per-minute production rate.
Source (both photos) | AGFM
FEATURE: Automotive Composites