Shielding of static magnetic fields by textiles

Low-frequency and static magnetic fields occur, e.g., in mains transformers, motors, oscilloscopes, strong laboratory magnets etc. They can be shielded only by materials of high permeability. For weak magnetic fields, mu-metal or Metglas have very high permeabilities leading to large shielding factors. However, both materials are not suited for larger fields, since the field-dependent permeability decreases significantly for magnetic fields of about 1 Oersted (Oe) or higher. In our experiments, we integrated metallic fine yarns fine and yarns from different magnetic materials into warp-knitted fabrics. These fabrics were formed into cylinders of defined diameter. The shielding factor was measured in the field range of +/- 100 Oe. Shielding ratios were found to be much lower than values of a solid steel bar; however, these experiments point out that shielding of static magnetic fields with magnetic textiles is possible in principle.