Production of bi-component polyester fibres for emr (Electromagnetic radiation) protection and examining emr shielding characteristics

Abstract

In this study, multifilament polyester yarns consist of bicomponent S/C (sheath/ core) fibres were produced in order to create electromagnetic shielding properties. Yarns were produced in 260 dtex linear density with 72 bicomponent filaments. The conductive additive material was nano iron oxide 20% (w/w) in PBT (polybutylene terephthalate) masterbatch.1, 2 and 3% masterbatch (20% nano iron oxide in PBT) were fed into the sample yam production device, however; acceptable yarn production could only be achieved by 1% masterbatch due to the high number of machine stops at higher amounts of additive material. Shrinkage at the boil and tenacity tests were performed on the produced yarns. Also, the produced yams were knit to form fabrics and test the EMSE (electromagnetic shielding efficiency) values by these knitted surfaces. The EMSE tests on the knitted fabric samples were performed basically according to ASTM D 4935 Coaxial Holder Method but the method used was a modified method that uses a smaller sample holder. The EMSE values at 30 MHz of the fabric samples knitted by the produced bicomponent yarns were measured as 18,78 dB and 13,59 dB for tight and loose stitch densities, respectively.