| 摘要 |
A method of coating a web with an electrically conductive composition comprises passing the web through the nip of a pair of horizontally mounted deformable rolls, which nip forms a reservoir for the coating composition, the pressure of the rolls at the nip, the height of the composition in the reservoir and the speed of rotation of the rolls being adjustable to give the desired resistance in the end product. The coating composition preferably contains electrically conductive particles in combination with colloidal silica particles with substantially no alkali content. In one preferred embodiment, a pair of electrodes are fed to the nip of the rolls, between a pair of webs of insulating material, e.g. asbestos paper. Various examples of suitable compositions, roll pressures and speeds &c. are given for obtaining the desired resistances. Examples of suitable substrates to be coated are cellulosic or asbestos paper, cloth, plastic films &c.ALSO:A method of coating a web with an electrically conductive composition comprises passing the web through the nip of a pair of horizontally mounted deformable rolls, which nip forms a reservoir for the coating composition, the pressure of the rolls at the nip, the height of the composition in the reservoir and the speed of rotation of the rolls being adjustable to give the desired resistance in the end product. The coating composition preferably contains electrically conductive particles in combination with colloidal silica particles with substantially no alkali content. In one preferred embodiment, a pair of electrodes are fed to the nip of the rolls, between a pair of webs of insulating material, e.g. asbestos paper. Various examples of suitable compositions, roll pressures and speeds are given for obtaining the desired resistances. Examples of suitable substrates to be coated are cellulosic or asbestos paper, cloth, plastic films. |
