Source: Envalior
This company is launching a new high-performance thermoplastic unidirectional (UD) tape for high-pressure all-thermoplastic hydrogen pressure vessels. With UDea® EcoPaXX®Q20HTC60, the manufacturer of high-performance plastics is offering a continuous fiber-reinforced tape, which can be used to wrap and mechanically reinforce polyamide liners. Thanks to the tape, the tank systems can withstand high pressure loads that occur during tank filling and storage. The new grade is based on polyamide 4.10 and reinforced with 60% by weight of UD continuous carbon fibers. The alternative carbon fibers used in the composite increase the tape’s tensile strength in fiber direction by more than 15% to around 2.2 gigapascals (GPa) compared to equivalent materials reinforced with lower strength carbon fibers. One method to apply the thermoplastic tape is via laser assisted tape placement. This can be done using the start-stop principle, reinforcing the liner only in those areas that are essential to withstand the high pressure. Non-load-bearing carbon fibers can be removed from the composite structure, which cannot be done with the incumbent wet-winding thermoset processing method. This results in weight and cost savings of up to 20%. A key advantage of the thermoplastic based composite material is its sustainability. Not only is the polyamide 4.10 partly bio-based, but as a thermoplastic composite it is also easy to recycle, in contrast to thermosetting epoxy systems used for pressure vessel winding. These must be landfilled or incinerated at the end of the pressure vessel’s service life. Also, wrapping the liner with the tape does not require any curing or handling of thermoset chemicals for which special occupational safety measures and cleaning protocols are required. Applying a polyamide 4.10 based tape to a liner made from a polyamide 6 compound causes the laser-generated melts of both polyamides to form a melt-melt contact at the interface, creating a monolithic structure with a strong material bonding. — Envalior, Düsseldorf, Germany