Italian equipment supplier Cannon Group has revealed that it is among the suppliers involved in the production of BMW AG’s carbon fiber reinforced electric vehicles.
Cannon, based in Trezzano, Italy, supplied production equipment for Benteler-SGL Automotive Composites epoxy processing technology for producing carbon fiber reinforced plastic.
Benteler-SGL, which is a joint venture between Benteler Automobiltechnik of Germany and SGL of Germany, is using the equipment at its plant in Ried, Austria, where it is making approximately ten CFRP components for the i3, which went on sale in November last year, and the i8 which enters production this year.
No details have been revealed about these components, but Benteler-SGL’s expertise is in structural parts including doors, rocker and A pillars, seat shells and rear spoilers. The BMW i3’s passenger cell, roof and seat shells are made in-house at BMW’s Leipzig and Landshut facilities.
Cannon said the automated production plant it supplied to Benteler-SGL includes: a high-pressure Estrim dosing unit for the epoxy resin application process; two presses with 1,000 metric tons of clamping pressure for the polymerization of parts; five handling robots for the manipulation of carbon fibers and finished parts; and associated electronic controls, safety devices and the storage facilities for chemicals.
Cannon’s says its Estrim (epoxy structural reaction injection molding) process is a faster alternative to traditional resin transfer molding of epoxy parts. The dosing unit supplied to Benteler-SGL uses Cannon’s liquid lay-down distribution method which deposits a liquid “ribbon” of formulated resin over the carbon fiber reinforcement.
Cannon said the uniform film of liquid impregnates the fibers once pressed in the mold. “The absence of in-mold flow of reacting resin coming from the mixing head reduces drastically the counter-pressure generated during injection, allowing for the use of low-tonnage clamping presses,” it said.
The cost advantages of the method, according to Cannon, are a smaller investment in molds and clamping tools and lower energy consumption during each cycle, which reduces production costs.
The Estrim mixing head technology allows fast-reacting formulations to be used, and parts can be demolded after only three minutes, said Cannon.
Recycled carbon fibers, which arise from preforming and trimming, can be used in the process to save on material costs.