Influence of water on the short and long term mechanical behaviour of polyamide 6 (nylon) fibres and yarns

Abstract

Polyamide fibres are known to be sensitive to water, and this has limited their marine applications. However, their low stiffness and high strength could be attractive for shallow water mooring line ropes, particularly for floating wind turbines. Such applications require the influence of water on mechanical behaviour to be fully understood, and this paper presents results describing how water affects static and creep response of polyamide 6 fibre yarns. First, the effect of water on fibre Tg is quantified, then tensile behaviour is examined. Finally, a model based on Schapery's non-linear creep analysis is identified for different humidity conditions. The results show that while moisture has a small effect on short-term tensile behaviour, long term response is strongly affected and this must be considered in any marine application.

Mechanical behaviour of 3D monofilament knitted fabrics: Modeling, simulation and validation

“…This profile may be seen in many melt-spun fibers, and comparable curves have previously been observed in nylon 6-6 fibers. 35, 36 The same domains may be found here:(1) From 0 to 5% strain, the curve depicts the amorphous areas aligning, while the crystalline domain remains unloaded. As a result of the crystallization produced by mechanical stress, amorphous areas are reduced and the crystallinity ratio increases considerably.(2) From 5 to 10% strain, the characteristic shape of the end of the amorphous domain orientation appears.…”

“…This profile may be seen in many melt-spun fibers, and comparable curves have previously been observed in nylon 6-6 fibers. 35,36 The same domains may be found here:…”

Origin of embrittlement in Polyamide 6 induced by chemical degradations: mechanisms and governing factors

“…Polyamide materials are widely used by the automotive industry [4][5][6], in oil and gas application, and also for wind turbine moorings [7]. Polyamide production has increased in the last 20 years to reach 5.5 million tonnes in 2015 [8] so the long-term behaviour of these polymers will become important in the future.…”

Challenges in Tensile Testing of Thermoplastic Composites Reinforced with Chopped Carbon Fibre Produced by Fused Filament Fabrication Method

“…Nylon is a hygroscopic material [46], for that reason, proper storage of this material before the printing process is necessary since the moisture absorption leads to a decrease in the melting temperature of nylon [47]. If the printer user does not adjust or cannot adjust the temperature of the nozzle, the nozzle dripping will occur.…”