| 摘要 |
<p>352,533. Impregnating paper. CALLENDER'S CABLE & CONSTRUCTION CO., Ltc., Hamilton House, Victoria Embankment, London, and HILL, H., of Callender's Cable & Construction Works, Belvedere, Kent. April 10, 1930, No. 11390. [Class 140.] Paper webs which are to be impregnated with liquid or semi-liquid material, for instance in the manufacture of electric insulation, are embossed so as to produce a number of small and preferably isolated raised areas, and then rolled up in such a way that the raised parts form spacers to keep the layers apart. The rolls are then impregnated in closed vessels. The embossing may take the form of conical projections 2, spaced at regular intervals. The spacing of the layers in the rolls permits penetration of the impregnant, so that, for instance, tar may be used to impregnate paper used to protect lead sheaths and armouring of electric cables. The process may be applied to fabric such as cambric.</p> |
