Development of Needle-Punched Nonwoven Fabrics from Natural Fibers for Sound Absorption Behavior

: The natural fibers prepared from plant waste have parameters like fiber strength, length, and chemical composition which are suitable to fabric and the fibers into nonwoven. The selected plants were identified from their botanical names by comparing the collected samples with those of known identity in the herbarium of a botanical survey in India with their names as Sesbania grandiflora, Mutingia Calabura, and Bauhinia Purpurea. A novel Portable multi-fibre decorticator machine was fabricated and used to extract the fibers from the plant stem and barks. The extracted fibers are done physical characterization and their properties are investigated. The extracted fibers are blended with other natural fibers like jute and flax in appropriate proportions 45:45:10 and nonwoven fabrics were prepared by the needle-punching method. Three and four-layer nonwovens are produced using a needle punching machine. The developed nonwovens are tested using standard apparatus and the effect of natural fibers in areal density, thickness; bulk density, porosity, and air permeability are analyzed. In addition, thermal conductivity and sound absorption behaviour are also investigated. The sound absorption property increases concerning areal density and fabric thickness. The thermal conductivity increased by increasing the fiber layer in the fabric to evaluate its potential as a protective barrier material in non-woven face masks.

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.

Modal Experiment and Analysis of Needle-Punching Machine

Modal analysis is a main method of researching the dynamic performance of the system structure. The deformation of Needle-punching machine frames in the work will affect the whole machine performance, which would seriously influence acupuncture frequency, reduce production efficiency. At the meantime, machine life will be shortened. Here, Needle-punching machine modal experiment has been done, the static natural frequencies and modal deformation animation of frame also has been calculated, that provides a reliable guide and basis for the actual work of deformation for needle-punching machine.

Vibration Analysis of Needle-Punching Machine Slider-Crank Mechanism

After analysis of the movement characteristics of needle-punching machine slider-crank mechanism in theory, a slider-crank mechanism acceleration curve had been rendered by MATLAB software and acceleration movement curve had been drawn after the measurement of acceleration of slider-crank mechanism by ADAMS simulation software. Through the comparison between the two results, a conclusion had been drawn. Finally, 3 advice of minishing vibration had been given according to the conclusion of calculation of acceleration by Quality Substitution Method,the first advice is the quality and site of the balance block are chose appropriately,the second advice is the weight of the slider and the connecting rod need to be reduced by choosing appropriate material.