Effect of Time and Temperature when Removing PVA from a PET/PVA Nonwoven Material

The study examined the effect of heat and time on fabrics made from polyester (PET) and polyvinyl alcohol (PVA) fibres which have different aerial densities and composed of 90% and 10% of PET and PVA respectively. PVA is included in the fabric due to its water solubility and this will allow the PVA to be removed thereby leaving a more porous fabric. The fabrics were passed through needle punching machine and PVA removed by heating in a water bath. The nonwoven fibre was then heated in water at temperatures of 75, 85 and 100 °C in an effort to remove the PVA fibres and leave a more porous fabric. While removing the PVA through heating in a water bath, the effect of heating period and the temperature on the fabric properties was investigated. The strength, elongation and structure of the fabric were investigated and the changes analysed. It was found that there was a significant removal of PVA at longer periods of time when at a high temperature. The effect on the properties was found to be higher with higher temperatures as well with a decrease in strength ranging between 40% and 60% being experienced while an increase in elongation, between 60% and 90% was experienced. Fibre spacing and pore size was found to have increased as well.