Effect of Packaging Material on Piezoelectric Response of Sensor with Electrospinning Polyvinylidene Fluoride (PVDF) Nanofiber Web

The polyvinylidene fluoride(PVDF)nanofiber web by electrospinning technology has the characteristics of fast response,high sensitivity,wide range of pressure,etc.,and provides new sensitive materials for the sensor testing the dynamic pressure such as foot pressure during walking.Because of the nanofiber mesh structure,it must be packaged to collect piezoelectric charge and bear strong mechanical behavior before industrial practice.The PVDF nanofiber web is usually packaged by incorporating a pair of flexible electrode as well as the lead of signal output.This present work will introduce the detailed packaging process and technology of PVDF nanofiber web,and three different types of packaging electrode materials(adhesive copper foil tape,indium tin oxide(ITO)thin plate,and adhesive conductive cloth)in previously published literatures are compared by the piezoelectric response of their sensor prototypes to a periodic mechanical activation.The results showed that the surface property of packaging material had a significant effect on the piezoelectric response of sensor by PVDF nanofiber web.For PVDF nanofiber web sensor,therefore,it needed a deep investigation on the specific packaging technology in terms of different working conditions.

Bending and Washing Reliabilities of Screen-Printed UHF RFID Tags Based on Woven Water-Mark Fabric

Compared with bar code and quick response( QR) code in the storage and retailing management of textiles, the ultra-high frequency( UHF) radio frequency identification( RFID) tags have high information capacity as well as reliability in complex environmental conditions. In this study,the UHF RFID tags with perfect integration with textiles are assembled with screen-printed antenna on woven water-mark nylon fabric and Alien UHF integrated circuit( IC), and their reading performance under various washing and bending conditions is evaluated by an RFID reader. The results show that the tags after fifty bending( both arch and sink) cycles of screen-printed antenna still have reading distance more than 5.5 m,and an average reading distance is over 4.0 m after five washing cycles. The experimental results demonstrate that the tag antenna on the water-mark fabric can be manufactured by the screen-printing technology,and a coating process on this fabric facilitates the reading performance and the resistance against complex mechanical impact.

Water Transport Models of Moisture Absorption and Sweat Discharge Yarns

An important property of moisture absorption and sweat discharge yarns is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yarns were developed to investigate the influence factors on their wicking rate. In parallel Column Pores Model, wicking rate is determined by the equivalent capillary radius R and length of the capillary tube L. In Pellets Accumulation Model, wicking rate is decided by the capillary radius r and length of the fiber unit assemble L0.

Study on Properties of Jute Fibres Spun on Ring Spinning System

Jute fibre properties,viz. linear density,mechanical properties,and fibre staple length were analyzed in this paper. Morphology,lignin content,and composition analysis for jute fibres were investigated in order to give further understanding of the fibre properties changing during the chemical treatment and yarn producing processes. The results show that jute properties are greatly changed during the processes of chemical treatment,breaking carding,and finisher carding,whereas slight changes can be found in the processes of drawing,roving,and spinning.

Study on the Structure and Properties of Polynosic Fiber Treated by Alkali

The regenerated cellulose fibers, made from wood pulp, have excellent physical properties like cotton fiber. Especially polynosic fibers can be mercerized by alkali, but conventional Viscose fiber can not be treated or mercerized by alkali. The paper studies on behavior of polynosic fibers treated by alkali, including physical properties, such as weight loss, tensile strength and elongation, and fiber structures properties. In this paper, on the basis of study on polynosic fibers treated by alkali, the conclusions were drawn as following. Firstly, polynosic fiber is good at alkali resistance. Secondly, the changes of fiber structure and physical properties begin declining at 5 wt% NaOH concentration and reverse changes take place at 10 wt%.

Modeling and analysis of the compact spinning yam structure by interference

The fiber stress and elongation after the yam twisting has been analyzed in this paper. A method has been proposed to improve the strength of compact spinning yam. A structure model of the interference compact spinning yarn was established. It theoretically proves that interference compact spinning yarn has higher strength than that of traditional compact spinning yarn.