CompositesWorld
Issue link: https://cw.epubxp.com/i/866813
SEPTEMBER 2017 66 CompositesWorld PLANT TOUR make these parts in a fully automated way with both lines inte- grated and running together, this is a challenge." All of the robotic arms are sourced through BENTELER, which also supplied a majority of the Volvo leaf spring line's machinery. "We have our own division in BENTELER Automotive internal mechanical engineering, which builds our equipment in-house," Ascher explains. "All of our process control software is developed internally as well." Only three technicians must be on the floor during production on this line, but others operate behind the scenes, monitoring system performance and re-engineering it, where necessary. Structured for continuous improvement Leaving leaf spring production, the tour stops by an enclosed control room, located mid-span on the north side of the hall, that functions as a "war room" for the whole plant. ere, metrics are tracked for logistics and employment, and to support efforts for continuous improvement — keys to ensuring performance at the site, in production, maintenance and safety. "is is a daily management area to have the right focus and find quick solu- tions," says Ernst-Seibert. "We plan ahead. is expertise comes from BENTELER Automotive." "is also serves to inform employees so they have a big picture and can see how to contribute to success," adds Birgit Held, VP corporate communications/marketing for BENTELER Interna- tional AG. "We also show and discuss ideas for improvement. It's about people — those working at this site know its operations and issues best. We need to benefit from their ideas, so we provide a structural loop for this." She says that employee ideas are awarded each year, and progress in addressing and implementing ideas is monitored. "For example, if it is taking too long for an idea to be answered, then it may go to the managing directors," Held explains, noting that reaction and answering time should not be too long. CFRP production e tour resumes, entering the CFRP production area. To the left is an automated cutting station with a long table. Up to 10 layers of material can be cut simultaneously as required for parts in production — four to seven plies is normal. A robot pulls rolls of reinforcement from an inventory shelf along the north wall. Each roll is scanned into the digital enterprise resource planning (ERP) software, which tracks inventory and overall production, but also builds a digital "paper trail" for each part. ere will be a barcode on the end of each part to log material and roll data. e precut material stacks are placed onto a cart that is then rolled a few feet to a heated press, where they are consolidated into a preform. e parts in production during the tour were transferred in and out of the press manually, but Ascher notes, "If the volume is high enough, we automate." Preforms are then fed into two HP-RTM presses. e machine shop for equipment maintenance lies just beyond the CFRP production area, in the building's northeast corner. Across the aisle from it is the wet pressing area (see Learn More). "Under-floor parts for automotive are a good shape for FIG. 5 Tracking products and data BENTELER SGL uses barcode, RFID and GPS-based systems to track materials and tools (above) to maintain efficient production and each part's digital thread. length is a mass-capable oven for post-curing the leaf springs (Fig. 4, p. 65). e process requires no manual steps, yet manages nine combinations of upper and lower tools and mates them with multiple machined hole configurations for spacers and bushings. As a result, it can output the appropriate leaf spring variants in response to an ever-changing mix of large and small vehicle orders (see Learn More). Walking up onto a mezzanine where the resin storage, heating, metering and mixing equipment is arranged, the tour turns to face west. From that vantage point, it is clear there are actually two mirrored leaf spring production lines. Rolls of glass fiber UD fabric enter and are processed in dual automated cutting stations. In each line, a robotic arm transfers cut plies onto stacking tables and then moves completed stacks into a dual-cavity press where they are consolidated into leaf spring preforms. On the other side of the preform press, a second set of robotic arms transfers preforms into one RTM press for each line. ese robots run on a linear track from the RTM press to multiple machining cells (Fig. 4, p. 65). "Making a leaf spring out of composite is not rocket science," says Ascher, "but how to set up this equipment and