New power train technologies based on hydrogen or natural gas, for example, are gaining more and more importance for resource-saving mobility solutions. For the economic storage of these fuels in vehicles, pressure vessels of type IV are suitable. They are based on a thermoplastic inner tank, also called liner, reaching the necessary pressure stability by fibre reinforcement using the filament winding process.
Type IV pressure vessels are characterized by their tremendous lightness and safety and are thus highly interesting for numerous applications in the mobility sector.
Roth Composite Machinery has recently delivered a customized Filament Winding Plant for the manufacture of hydrogen tanks with three spindles. Dr. Andreas Reimann, General Manager of Roth Composite Machinery, explained: “A high-performance drive concept combined with a new machine frame structure enable performance improvements of about 40 percent compared to the international state of the art.“
The machine concept comprises five interpolating axes and additionally five CNC programmable axes. The set-up of the machine is suitable for series production as well as for development applications (R&D) using the traditional wet winding process. Through separation, the impregnating station enables an individual use of single spindles in order to avoid unnecessary consumption of resin. An NC-controlled doctor blade allows a precise and reproducible adjustment of the resin gap. The movable impregnating station is suitable for the processing of carbon fibres as well as for glass fibres and reduces the roving load due to decreased wrap angles. By means of the fibre storage device, even very low fibre tensions can be adjusted in line with the process due to the double cylinder control. Constant fibre delivery speeds of up to 4.5 meters per second can be realized.
The production line is prepared for a quick and easy change to the towpreg winding procedure. Through the use of the ROTH RCA (automatic roving cutting and applying device), the automation level of the machine is increased. For the winding of pressure vessels, for example, the machine is equipped with an automatic pressurization and pressure measuring system which is able to create and regulate the necessary inner pressure of the liner during the winding process. The exceptional machine stiffness minimizes mechanic impact on the manufacturing process and ensures highest precision during the filament winding process.
18 June 2021