The aim of this study is to investigate the electromagnetic shielding effectiveness (EMSE) of thin and lightweight knitted fabrics that are suitable for casual wear like t-shirts. For the purpose of having a low production cost, metal/cotton conductive composite yarns are produced by a yarn doubling technique, involving stainless steel wires (35 m, 50 m) or copper wires (50 m, 70 m) and Ne30/1, Ne40/1, Ne60/2, Ne80/2 count cotton yarns. Single jersey fabrics are knitted on an E20 circular knitting machine with the same machine settings. Coaxial transmission line and free space measurement (by using an anechoic chamber) techniques are used for the EMSE measurements in the frequency range of 100 MHz-1.5 GHz and 1 GHz-18 GHz respectively. The free space measurement technique test results reveal that single jersey knitted fabrics have EMSE ability for the electric field polarization in the same direction as the main direction of the conductive metal wires in the fabric. It is observed that all single jersey fabric structures have more than 7 dB (80% or better) EMSE for GSM-850 and GSM-900 cellular phone communication bands according to coaxial transmission line equipment test results. SNK test results of both test methods reveal that, while 100% cotton fabrics do not have EMSE ability, cotton yarn count is highly significant on the EMSE of single jersey fabrics with conductive composite yarns. Fabrics with two-ply fine cotton yarns (Ne60/2 and Ne80/2) have higher EMSE values than the fabrics with one-ply cotton yarn of the same yarn count (Ne30/1 and Ne40/1).

In this study, the effects of spandex brand, the tightness factor of the base, and spandex yarn on the dimensional and physical properties of cotton/spandex single jersey fabrics are investigated. In order to examine the effects of the tightness factor of cotton and spandex yarn, fabric samples were knitted by feeding both cotton and spandex yarns with three different adjustments of positive yarn feeding mechanisms so as to produce tight, medium, and loose cotton/spandex single jersey fabrics. Four different spandex yarns were used. The fabrics knitted with spandex yarns that have the largest tension values under a constant draw ratio give the highest weight, courses/cm, stitches/cm, thickness, and lowest air permeability values. Spandex yarns that have similar elongation % values affect the wale per cm values in a similar way. Because of the greater stretched structure of the spandex yarns that have shorter loop length values, the width of the fabric decreases and then the thickness of the fabric increases.

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In this study, biodegradable polycaprolactone (PCL) nanofibers were copper (Cu) electroplated in a more environmentally friendly bath compared to conventional electroplating baths. The Cu-plating mechanism and determination of the optimum parameters for the production of Cu-plated PCL nanofiber mats were explained. PCL nanofibers were produced on metal frames by electrospinning. Cu-electroplating needs a conductive surface. To provide this, a gold/palladium mixing was sputtered on the PCL samples with different sputtering thicknesses. After determining the minimum sputtering thickness, the samples were Cu-plated for 1,3,5 and 30 minutes in the electroplating bath. Surface properties of the samples were evaluated after nanofiber production, Au/Pd sputtering and electroplating, respectively. Elemental analyses, mapping and electrical characterizations were also performed after electroplating. The Cu-coated areas gave a sheet resistance in the range of milliohms indicating a highly conductive structure. Every step of the study is described in detail to provide insight for further studies.

The aim of this study is to investigate the influence of knitting structure and metal wire amount on the electromagnetic shielding effectiveness (EMSE) of knitted fabrics comparatively. Single jersey, single pique, weft locknit, and cross miss fabrics involving stainless steel or copper wires were produced on a flat knitting machine. A free space measurement technique was used for the EMSE measurements in an anechoic chamber. The variance analysis results of the EMSE values reveal that the effect of knitting structure, metal wire type, metal wire amount, and incident wave frequency is highly significant. It was observed that fabrics with tuck and miss loop structures had higher EMSE values than single jersey fabrics. It was found that single pique fabrics had higher EMSE values than single jersey fabrics that contain twice as much metal wire. It indicates that changing the knitting structure is more effective than changing the metal wire amount.