Friedrichshafen, Germany — Steel rebar has been a standard in reinforcements. A German injection molding wants to replace steel with thermoplastics.
Heroldstatt, Germany-based injection molder 1A Autenrieth Kunststofftechnik GmbH & Co. KG launched a thermoplastic option to both steel and glass-reinforced composite at Fakuma 2023 in Friedrichshafen in October.
Autenrieth's thermoplastic moldings consists of a wire-shaped pultrudate with polypropylene, reinforced with 30 percent continuous glass or carbon fibers.
The pultruded wires are bent on equipment from Reutlingen, Germany-based wire bending machinery producer Wafios AG, forming complex 3D structures, which are placed in an injection mold and overmolded with thermoplastic.
The selective nature of the encapsulated reinforcement brings load-oriented stiffness and strength to the parts of moldings where they are most needed, which would otherwise require moldings to be much thicker and heavier for the same strength and rigidity.
The Wafios equipment can create complex, star-shaped rebar without shaping tools by alternately bending the profile to the right by 72 degrees and to the left by 144 degrees.
Rebar was developed in Germany by 1A Autenrieth; Augsburg-based Fraunhofer IGCV institute for casting, composites and processing technology; Coburg-based automotive components Brose Fahrzeugteile SE; and automaker Porsche.
The German Federal Ministry of Education and Research (BMBF) funded the project as part of the HYMAT materials platform for hybrid materials. It received an innovation award at the 2023 JEC World composites fair in Paris.
The DRIFT production line at IGCV involves a winding machine from Oldenburg, Germany-based Herzog GmbH that feeds wound glass fiber roving directly into IGCV's pultrusion line, followed by bending.
Two large-scale auto demonstrations have been developed, but Porsche does not yet want to reveal any details, except that they are aimed at applications in the Porsche Taycan.
It enables high-volume, cost-effective and resource-saving production of complex lightweight structures with high design freedom. One of the two demonstrators produced in the project offers 50 percent weight savings compared with deep-drawn aluminum — 0.95 kilograms instead of 1.83 kg.
1A Autenrieth foresees application areas for rebar hybrid technology in aerospace, mechanical engineering, auto, utilities and consumer products.
Steffen Autenrieth, managing director since 2006, said: "Rebar can be used wherever metals are currently used, which would ultimately be more cost-effective, safer and conserve resources."
Autenrieth explains that "1A" in the company's name was a deliberate strategy in order to be listed high up in B2B databanks and the company register, without having to pay for a privileged position.
The company was founded in 1977 by Heinz Autenrieth. Its 18 injection molding machines at 1A Autenrieth cover clamping forces of 50-462 tonnes, capable of molding shot weights from 0.1 to 1,500 grams. Its present machine park list shows SHI Demag accounting for 13 of the machines, along with machines from Dr. Boy and Battenfeld, but two unspecified machines have been recently replaced by Arburg machines.
Fused deposition modeling 3D printing machines acquired in 2020 produce parts in ABS, ASA, nylon 12, polycarbonate, PC-ABS, PEI and PEKK, in build volumes up to 406 by 355 by 406 mm.
1A Autenrieth Kunststofftechnik GmbH & Co. KG
Hall B1, Booth 1009