Production of customized impregnated and width-fixed fiber tapes
For producing impregnated and width-fixed fiber tapes, Cetex Institut gGmbH developed a system technology. As part of a research project, the development involved three stages, from preliminary tests to a prototype machine and finally to custom-made production systems.
The development aimed at converting a standard spooled fiber roving into a flat ribbon and to preserve this state by applying a liquid matrix and subsequent thermal activation. The semi-finished product should then be wound as a cross or disk bobbin.
Fixed carbon/PEEK tape
Profound preliminary tests
The preliminary tests were carried out using aramid rovings with 1670 dtex. The width of the aramid roving of around 2 to 3 mm should be increased to a width of up to 6 mm with a fiber content of 90 to 95 %. The general spreadability of various aramid types was demonstrated in this stage.
Spreading fiber rovings uses the principles of rope friction: as a result, the individual filaments spread out and the original roving width increases significantly, depending on the type of fiber. With the technology now developed, for example, the ribbon width of a 12 K carbon roving can be increased from 10 mm to over 17 mm.
The spread ribbons are then coated with a liquid matrix using various technological approaches. For instance, the ribbons were pulled through a dip tank via fixed deflections or guided through various arrangements of squeeze or scoop rollers. The coated spread roving was fixed using infrared technology and thermal convection, whereby the water content of the liquid matrix evaporates and the matrix remaining
on the spread ribbon is melted.
Prototype machine
Following the successful preliminary tests, a prototype system was developed for coating up to eight tapes. It achieves a production speed of up to 20 m/min and winds end widths of up to 10 mm as a cross-wound bobbin. The physical implementation of this 8-track prototype machine and successful production trials led to the next step: customised installations.
Customized systems
For Filament-Technik GmbH & Cie. KG, a highly scaled test system for up to 30 doubled, coated and fixed aramid fiber tapes was created. The production speed of this 28 m long system is up to 60 m/min. The semi-finished product is used in cable-wrapping, as part of heat shields, and in leisure sports for reinforcing structures in the canvas of sports yachts.
The Technology Innovation Institute in Abu Dhabi also received a similar system in 2024. It enables the parallel production of up to ten impregnated tapes, consisting of 12K carbon fibers coated with a PEEK dispersion, at a line speed of up to 10 m/min. The product achieves a fiber volume ratio of 60 % and a tape width of up to one inch in the doubled state, wound up on a disk bobbin.
Both systems are based on the modular principle. In the coating module, they have a filter circuit which enables permanent circulation, the supply of fresh coating medium and the filtering out of filament residues.
Fiber coating system for carbon /PEEK
Contact:
Cetex Institut gGmbH, Chemnitz
Dipl.-Wi.-Ing. Sebastian Nendel, Managing Director
+49 371 52 77-200
nendel@cetex.de
www.cetex.de
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