A cost-effective method for obtaining single magnetic cotton yarns

In this work, we propose a cost-effective procedure to obtain magnetic single cotton yarns by employing commercially available magnetic powders and adhesives. Two different indirect magnetization methods are used on the yarns coated with several mixtures containing barium hexaferrite (BaFe12O19) as hard magnetic powder. The BH mass percentage is varied between 10% and 50%. Specific textile coating binders such as polyurethane and polyvinyl acetate are used as adhesives. A constant amount of 5% glycerol is employed as plasticizer agent. An in-house developed laboratory equipment is used to produce the magnetic cotton yarns. The equipment allows primary orientation of the magnetic particles along external field lines and subsequent magnetization until saturation. Our studies show that the diameter of the coated yarns is directly dependent on the amount of magnetic powder in the coating solution. Thus, the magnetic yarn diameter increases by 30% when compared to the 356 mu m diameter of the reference (uncoated) yarn for a barium hexaferrite mass percentage of 50%. Also, our studies reveal that increasing the magnetic properties (residual magnetism and coercive field intensity) of the composite yarns is possible only by increasing the mass percentage of the magnetic powder content. The highest values of the magnetic properties have been measured when neodymium permanent magnets (NdFeB) were used for the magnetization instead of a toroidal coil. The residual magnetization and saturation increase with the amount of barium hexaferrite embedded in the textile yarn. However, the increase in mass percentage is limited by the degradation of the yarn properties which allow them to be used for textile applications. SEM images of the coated yarns reveal a relatively uniform deposition of magnetic layer on the reference cotton yarn.