CompositesWorld
Issue link: https://cw.epubxp.com/i/841219
NEWS 27 CompositesWorld.com Automated Preforming, Part 1 rotary table, the STAXX Compact 1700 offers a material feed rate of 40 m/min, a layup rate of 30 kg/hr, and a pallet size (part layup area) of 1,525 mm by 900 mm. It also offers a scrap rate potentially below 5% vs. the 50% Meyer asserts is typical in textile preforming for parts of this size. e rotary table and buildup of layered blanks appears similar to Dieffenbacher's (Eppingen, Germany) Fiber- forge RELAY Station. Meyer contends that RELAY is using auto- mated tape laying (ATL) with ultrasonic spot-welding, not AFP with continuous compaction, and that the STAXX rotary table also can accommodate 500 mm of z-directional travel, which enables integration of sandwich core and specialized inserts. "We use a zero-point clamping system for just this reason," Meyer notes, adding that, either manually or via automated pick- and-place robot, "you can take the pallet out and equip it very accurately with inserts, and then put it back into the cell with toler- ances below 0.1 mm." He points out that although this is new for AFP, it is considered standard in the metal-cutting industry, as is much of the CNC control designed into STAXX. For example, "It has two bays," he says, "so that you are loading one part while laying up another simultaneously, in order to maximize throughput." Meyer also claims a big advantage in design freedom with regard to fiber orientation. "STAXX can place fiber at any angle between 0° and 180°, in increments of 0.01°," he claims. Parts demonstrated, thus far, include automotive tunnels, floors and B-pillars. "We have shown that we can supply … B-pillars from a single machine for a luxury car at 100,000 units per year," Meyer contends. "We can also make aerospace parts, like ribs, clips and brackets, as well as industrial parts." ATL at 10-15 seconds per layer FILL Gesellschaft (Gurten, Austria) supplies innovative machinery for production in metals, plastics, wood and fiber-reinforced composites. "Preform automation is one of our main fields," says Wilhelm Rupertsberger, head of FILL's composites competence center, noting systems developed for BMW and Audi, including a machine for the carbon fiber-reinforced plastic (CFRP) rear wall of the new Audi model, as well as equipment for CFRP wheels at Tier 1 suppliers to other companies. "All of these machines automate preforms for RTM," he adds. Although FILL has sold a number of units for cutting, stacking and hot-drape forming unidirectional and noncrimp fabric rein- forcements into composite preforms, its latest development is an adaptation of ATL. e MultiLayup System (pat. pend.) uses dual arrays of vacuum rails to convey tape from two magazines of up to 16 reels each. Both material feeders unroll and cut the designated tape from each reel to a tailored length, as determined from the part's CAD file analyzed by FILL process software. "Connection between CAD data to CNC control is one of our strengths," explains Rupertsberger. e cut tapes required for a given ply in the preform are then transferred by a vacuum gripper system to a segmented rotary deposit table with 100 mm of z-axis movement. e vacuum gripper's integrated heating strips join/consolidate each ply of tapes to the next layer on the table, producing a tailored near-net shape preform (Fig. 2, p. 28). e FIG. 1 Cored preforms for auto parts at 100,000 per year The STAXX Compact 1700 automated fiber placement (AFP) workcell, developed by Broetje Automation (Rastede, Germany), can lay up preforms from towpreg or slit tape at 30 kg/hr, with integrated sandwich core and/or inserts, supporting production of as many as 100,000 automotive parts/yr. An exemplary automotive preform is above, with the formed part at top right. Source | Broetje Automation