CompositesWorld
Issue link: https://cw.epubxp.com/i/841219
JULY 2017 26 CompositesWorld Preforming goes industrial, Part 1 ATL- and AFP-based options now abound for processing dry and/or impregnated reinforcements as quickly as 1 minute or less with potential yearly part yields in the millions. » In the race to reduce the cost and cycle time of composite parts, automation has successfully transformed cutting, molding and machining into processes more suited to industrial produc- tion. However, when CW last looked at the manufacturing step of preforming — the process of preparing the reinforcements used to mold three-dimensional (3D) parts — it was still a production bottleneck: a complex, step-intensive, often manual process (see Learn More, p. 30). In the three years since, the emerging tech- nologies that could automate preforming have proliferated and are finally reaching maturation. In Part 1 of a two-part series on the topic, CW looks at a wide variety of new commercially avail- able systems that benefit from robotics combined with preform building processes adapted from automated tape laying (ATL) or automated fiber placement (ATL) technology. Enclosed automated fiber placement cell In 2015, Broetje Automation (Rastede, Germany), a supplier of specialized production systems (e.g., handling, preforming, assembly, machining) for the aerospace industry, introduced its STAXX Compact 1700 automated AFP workcell for near-net shape preforms (Fig. 1, p. 27). "When we started development, there were many companies focused on automated fiber placement for aerospace," says Dr. Matthias Meyer, VP of Broetje Automation's subsidiary BA Composites GmbH (Grenzach-Wyhlen, Germany), "So we focused on automotive and industrial parts, and also on using a low-cost input material — towpreg." is also motivated the unit's design as an enclosed, climate-controlled cell with a footprint of 3m wide by 6.5m long by 3m high — a compact system that could be put into production quickly in practically any facility. Meyer, who defines towpreg as a carbon fiber roving impreg- nated with a typically epoxy matrix, notes that the STAXX also can process dry fiber with binder applied ready for subsequent liquid molding, or a thermoplastic product, which, after preforming, is simply thermoformed into finished parts. (STAXX also can process slit prepreg tape because it can remove the backing film, but its use increases cost because it requires post-prepreg slitting operations.) Comprising two magazines, each housing 16 spools for towpreg feed, an AFP head with a compact clamp/cut/restart unit and a By Ginger Gardiner / Senior Editor Complex, tailored preforms in as little a minute The Quilted Stratum Process was developed by a partnership between the French government, French composites suppliers, including Pinnette Emidecau Industries ( Chalon sur Saône), and Nantes, France-based Cetim. It can feed, cut and assemble multi-thickness, multi-oriented unidirectional thermoplastic tapes into tailored preforms in 40-90 seconds. It can produce complex parts with molded-in holes and inserts in cycle times of 1-2 minutes. Source | Cetim