Determination of electromagnetic shielding performance of plain knitting and 1X1 rib structures with coaxial test fixture relating to ASTM D4935

Abstract

In this study, electromagnetic shielding effectiveness of some weft‐knitted structures is investigated. For this purpose, weft‐knitted structures are produced using copper wire/cotton incorporated yarns. Conductive yarns are produced by yarn‐folding machine. Four knitted constructions (plain knitting, weft in‐laid plain knitting, 1X1 rib, and weft in‐laid 1X1 rib) are formed into knitted structures with conductive yarns by using 7G flat knitting machine. Electromagnetic shielding values of test samples are determined by a coaxial test fixture relating to ASTM D4935 test standards. Measurements are made in the frequency range of 27 MHz–3 GHz. The effect of conductive content, stitch density and fabric construction parameters are investigated considering the electromagnetic shielding performance of weft‐knitted structures. Test results show that weft‐knitted structures investigated in this study have 10–40 dB shielding effectiveness under the frequency of 500 MHz.

Keywords:

• electromagnetic shielding effectiveness
• ASTM D4935
• electromagnetic shielding fabrics
• weft‐knitted structures
• conductive yarn

Acknowledgements

The authors appreciate the Board of Project of Süleyman Demirel University (Project No. 107‐M‐368) and the Scientific and Technological Research Council of Turkey (TÜBİTAK, Project No. 1438‐D‐06) for supporting their study. They also thank to York EMC Services Ltd. for testing the shielding effectiveness tests.