| 摘要 |
798,807. Coating and impregnating webs. BRITISH INSULATED CALLENDERS (SUBMARINE CABLES), Ltd. Feb. 5, 1957 [Feb. 6, 1956], No. 3651/56. Class 140. Sheet material is coated and/or impregnated as a continuous operation by drawing two or more sheets at the same time from separate supply rolls, winding them up into roll form separately, and between the unwinding and winding stages, whilst they are travelling at substantially the same linear speeds, heating them, subjecting them to low pressure, and drawing them through the treating liquid maintained at a higher pressure, the sheets being so guided that during their heating and low pressure treatment and at least the initial part of their travel through the treating liquid, they are in contact with one another. The sheet materials may be of paper or textile and they may be treated with oils, insulating compounds, varnish and rubber solution. The treated materials may be used as dielectric materials in an electric cable. As shown, sheets 7 and 8 pass from rolls 5 and 6 around guide rolls to roll 15 where they are united, around roll 15 back to roll 16 and from the bottom of roll 16 to a slot in vacuum tank 17. The rolls 15 and 16 may be heated electrically through slip rings 25 on their spindles. The slot into the vacuum tank is packed by a rubber bar 29 carried by an adjustable metal bar 31 and lying adjacent a steel bar 33. Within the vacuum tank the sheets travel over guides 40, 41 and 42 which may be heated and/or the tank may be heated), through a packed slot and into the impregnating tank 50 which is filled with liquid to a point above the guide rolls 47 and 49. At roll 49 the sheets are separated and pass through slots to a lagged tank 55 where both sides of each web are wiped by bars 44 mounted on angularly adjustable spindles 53. Sheet 7 then passes over guide rolls to roll 69 which dips in a trough and may apply a surface coating to the web. Sheet 8 passes over a similar roll 73 and the webs are reunited and pass round rolls 76, 77 and 78 from whence they are separately wound on rolls 80 and 81 repsectively. A barrier 120 in vacuum tank 17 separates the tank into two compartments from one of which any impregnant escaping from the tank 50 may be pumped back to tank 50. The rolls 76, 77, 78 80 and 81 are connected through reduction gearing mechanisms and clutch systems such that their speeds are substantially synchronized and so that the increase in diameter of rolls 80 and 81 may be compensated for. |
