| 摘要 |
Battery separators are provided with projections 33 on the main relatively flat surface 39 thereof formed from a web. The method of the invention overcomes or mitigates problems of damage to the web and use of organic solvents by a substantial departure from the conventional methods of forming projections as embossed ribs. In the invention, globules, e.g. of a plastics material, are fired at the web and made to stick to it, at least on cooling. Thus they are projected through a gas gap, normally an air gap, to provide substantially rounded projections. Any uneven-ness of the projections can be removed by passing the resultant web through thickness-sizing rollers. <IMAGE> |
