Patent GB-1469785-A (GB)
Title: Corrugator and method of making corrugated paperboard
IPC: B31F1/24
Filed: 1974-06-13
Abstract: 1469785 Corrugated paperboard HARRIS-INTERTYPE CORP 13 June 1974 [13 June 1973] 26377/74 Heading B5N A corrugator for producing corrugated paperboard comprises at least one single facer machine each selectively and operatively associated with a double facer machine by way of a bridge extending therebetween, a discrete drive for each of the machines, each drive including a power unit and a motor, a discrete comparator coupled between each motor and its power unit and means including the comparators for causing the speed of each single facer machines to follow the speed of the double facer machine in synchronization therewith. The means may include feedback circuitry coupling each motor with its respective power unit for correcting any deviation between actual and desired speeds of the motors and switch means for selectively coupling a speed reference signal of the double facer machine to control each single facer machine so that each single facer machine may selectively operate independently or in synchronization with the double facer machine at variable speeds. In the drawings corrugator 10 includes first and second single facer systems first and second single facer systems 12 and 14. In single facer system 12 liner 18 is fed from stand 16 through tension control device 20 and dual drum preheater 22 and in single facer machine 24 is adhesively bonded to corrugated medium 30 fed from stand 28, through preconditioner 32 having a steam shower system to machine 24 where it is corrugated. The single faced web 36 is fed by conveyer 38 to the upper level 40 of bridge 42 via web break detector 34. Single faced web 35<SP>1</SP> similarly produced in single facer system 14 is fed by conveyer 44 to the lower level 46 of bridge 42. Webs 36 and 36<SP>1</SP> are then passed around bridge guide 48, preheated by passage around heated drum 50 and coated on the crests of the flutes with adhesive in machine 57. Liner 56 fed from stand 52 is preheated by passage around heated drum 58 and then single faced webs 36, 36<SP>1</SP> bonded to each other and to liner 56 in double facer machine 60 provided with heated chests or plates below the web of paperboard and selectively movable to a minimal heat transfer position as a function of decreased speed. The web of paperboard is then cut transversely by rotary shear 62 into sheets which are fed by conveyer 65 in a transverse direction to a slitterscorer which slits and/or scores the sheets into strips while trimming the edges. The wrap of the single faced webs and liner in the preheaters may be adjusted to be proportional to the speed of the webs and in the preconditioners the valves for the steam shower may be motor controlled and correlated with respect to web speed and weight grade of the webs. The number of shower valves used in the preconditioner and the width of the glue application zone may also be controlled automatically corresponding to the width of the webs. When sheets of different type are to be produced a gap in the web is produced the components of the corrugator are operated at a reduced speed, the cut off machine is adjusted to a new length of sheets and the slitter blades adjusted in position and the machine then adjusted to operate at increased speed.