摘要 |
A sheath for tubular storage battery electrodes has an inner layer of an inert fibrous material and an outer layer of thermoplastic material in the form of a net, perforated foil, or the like. The two layers are mechanically joined by heating the fibrous layer to a temperature sufficient to soften the adjacent surface of the thermoplastic material and cause a portion of the fibrous layer to be embedded in the surface of the thermoplastic layer. |