| 摘要 |
1317037 Apparatus for impregnating corrugated cardboard BOISE CASCADE CORP 3 Dec 1970 [9 Feb 1970] 57477/70 Heading D1L In the impregnation of corrugated cardboard by supplying an impregnant from a stationary supply adjacent one edge of a longitudinally travelling board and drawing this through the flutes of the board by a stationary vacuum device adjacent the opposite edge of the board, means are provided for preventing lateral displacement of the board towards the suction means during the impregnation step. As described, a pair of endless belts 56, 66 is arranged between the suction and impregnating devices 96, 94, the cardboard 16 passing between the belts in sandwich fashion. Creation of a vacuum in the cardboard draws the belts into sealing contact with the board. The belts are prevented from lateral displacement by ribs on their backs which engage grooves in their driving rollers. These rollers may be accurately positioned by screw thread adjusters. The suction and impregnating devices each comprise a channel shaped member 96, 94 which engages an edge of the board, and lateral adjustment is provided by mounting them on sliding members 90 in a fixed frame, movement being effected hydraulically by pistons 96-102. The whole belt and impregnating/suction unit may be mounted for movement between an operative and inoperative position. A seal may be provided at the edges of each channel, comprising a pair of, e.g. plastic strips, between which the board runs, one strip being spring biassed toward the other (Figs. 8-10, not shown). The channels may be built up from a plurality of sections, and in the case of the impregnating channel, a first set of openings therein is connected, via valves, to an impregnant supply and a second set, downstream, is connected to supply hot air. The vacuum circuit on the other edge may include an impregnant recovery device. In one embodiment a - stream of impregnant is passed continuously through the impregnant channel and is drawn as required into the board; alternatively the impregnant may be positively blown into the board, or supplied as a dispersion from turbulence jets. Both suction and impregnating channels may be heated, e.g. by passing a fluid through internal passages. In one arrangement the channels form complete impregnating and suction units which are laterally movable as a whole on hydraulic pistons. Long lists of suitable impregnants are given, e.g. waxes and polymers. Reference has been directed by the Comptroller to Specification 1243689 |
