![]() A robotic arm sprayed chopped glass fiber and binder (3-5 percent by weight) onto a part-shaped screen through which vacuum was applied. ![]() The Programmable Powdered Preforming Process (P4) technology was originally developed by Owens Corning Composite Solutions (Battice, Belgium) and Aplicator System AB (Molnlycke, Sweden). By 2008, it had partnered with Sotira Composites (Saint Méloir des Ondes, France) to make 50,000 parts per year for Aston Martin's DB9 coupe, DB9 Volante, V8 Vantage and V8 Roadster models. Ford actually worked on chopped-fiber preforming in the 1990s. Straight and curved profiles up to 24 m long with no wrinklesįrom 2005-2009, automated preforming consisted mainly of 3D textiles for aerospace applications and directed fiber preforming for resin transfer molding (RTM) of automotive and transportation parts. (e.g., 13 patches of 1.5-, 2- and 3-mm thick organosheet and UD tape with fittings integrated)Ĭontinuous roll-forming for profiles: Straight, ≤10 plies at 400 mm/s Up to 490 kg/hr and 4m 2 parts up to 5 m/s for thermoplastic tapesġ0-15 seconds per layer for parts up to 4 m 2 ![]() New Dieffenbacher Fiberforge Relay System According to Thomas Dobiasch, head of sales for Compositence (Leonberg, Germany), “We have also demonstrated with BMW that we can preform 3.5 million parts per year with an output of 250-kg per hour on one machine.”įour 1.25 m × 0.75 m preforms in 60 econdsġ00,000 B-pillars/yr from one machine up to 40 m/min (≈670 m/s) In fact, production of 100,00-500,000 parts per year is just the beginning. Today, there are multiple technologies and players that claim the ability to produce high-quality, continuous fiber preforms in 90, 60 and 40 seconds. The target for preforming was to match the 1- and 2-minute molding cycle times, which-according to a 2015 presentation by automotive supplier Faurecia (Nanterre, France)-enable 1,000 and 500 parts per day, respectively, for mass production of 200,000 and 100,000 parts per year. “Right now, molding is not the time-critical part of the process,” said Matthias Mayr, head of project management at Engel Austria’s (Schwertberg) Center for Lightweight Composite Technologies. Where lightweighting is less critical and a lower fibre volume fraction can be acceptable, the designed stitch head has been shown to be a viable alternative to 3D orthogonal weaving for improving damage tolerance through reduced damage area and maintaining low crimp levels.In my 2015 article, preforming was seen as a bottleneck, with cutting, positioning and forming of fabric layers taking much longer than the molding cycle. In lightweighting applications requiring an improved damage resistance, low density stitching has been shown to be a suitable alternative to low density weaving, reducing the damage area under impact and maintaining a higher fibre volume fraction. This resulted in improved compressive strength retention after impact for the high binder density structures due to lower in-plane crimping, reduced damage extent under impact and impaired delamination growth under compression loading. Under low velocity impact loading orthogonal stitching was shown to be comparable with orthogonal weaving for improving damage resistance. This lower binder density enables more in-plane tow shifting during infusion and therefore results in higher crimp levels. In comparison at a low binder density, both show an improved compressibility and therefore a higher fibre volume fraction. This results in resin rich zones and a low fibre volume fraction. At the high binder density both the woven and stitched preforms experience a resistance to compression during infusion. Crimp levels are found to be only marginally higher in the stitched composite, although with higher tow damage visible. Analysis of the produced stitched composite shows the capability of the developed stitch heads to create a comparable stitched cross-section profile to that of a produced 3D orthogonally woven specimen. The two robotic stitching heads utilise the transfer of a double-pointed needle between the heads to produce a disjointed stitching pattern on the preform's surface, known as orthogonal stitching. This research details the design and development of a novel stitching technology capable of replicating the orthogonal woven binder profile in cross-ply composite preforms. Current weaving and stitching technologies have limitations that prevent industrial uptake. Weaving and stitching technologies currently exist that are able to create such 3D fibrous preforms. These 3D structures are known to typically improve interlaminar shear strengths, reducing the occurrence of delamination under complex out-of-plane loading situations such as an impact event. AbstractThe benefits of introducing through thickness tows to produce 3D fibrous structured composites have long been studied.
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