US2987105A - Method and apparatus for producing corrugated paperboard - Google Patents

Description

J. P. GEBBIE 2,987,105 METHOD AND APPARATUS FOR PRODUCING CORRUGATED PAPERBOARD June 6, 1961 Filed Dec. 24, 1957 INV ENTOR.

A TTOPNEK.

2,987,105 METHOD AND APPARATUS FOR PRODUCING CORRUGATED PAPERBOARD James P. Gebbie, Trenton, NJ., assignor, by mesne assignments, to Koppers Company, Inc., Pittsburgh, Pa., a corporation of Delaware Filed Dec. 24, 1957, Ser. No. 704,946 8 Claims. (Cl. 154-32) In ythe production of corrugated paperboard it has long been conventional to pass the constituent materials through a so-called doublebacker machine wherein single faced cornlgated paper carrying freshly applied adhesive on the exposed peaks of its corrugations, is bonded to a facing sheet, the superposed sheets being subjected to heat and pressure in the doublebacker to set the adhesive and dry out moisture, producing a traveling sheet of corrugated paperboard wbich then passes through a slitting and scoring mechanism by which the board is divided longitudinally into sections of desired widths, after which the sections pass through a cutoff mechanism which severs them transversely into blanks of desired sizes.

In operation-for example when the slitter-scorer and the cutoff are being reset to produce blanks of ditferent sizes, it is sometimes desired either to stop the feed of the material through the doublebacker for a short period, or to temporarily operate the latter at speed markedly lower than normal. When thus slowed down or held stationary, the material in the heating section of the doublebacker is subjected to the heat thereof for an abnormally long period.

The present invention aims to alleviate injury to the corrugated paperboard as caused by such abnormally long heating. In accordance with the invention, under the above abnormal operating conditions moisture is added to the material while passing to the heating section of the doublebacker `or while passing therethrough, or both, by subjecting the traveling material to moisture laden sprays or equivalent wetting apparatus which is inactive in the normal range of production speeds, but is automatically cut into action when the speed of travel becomes abnormally low, and remains in action so long as the material keeps on traveling abnormally slowly through the doublebacker, being automatically cut out of action when the doublebacker stops, and also when normal production speed is resumed. The `additional moisture content thus supplied to the partially completed paperboard enables the latter to remain in the heating section of the doublebacker without injurious overheating or drying, for the short shutdown or slowdown periods needed for resetting the machinery as aforesaid to produce blanks of different sizes. Further objects and advantages of the invention will be in part obvious and in part specifically referred to in the description hereinafter contained which taken in conjunction with the accompanying drawings discloses somewhat schematically, a preferred form of doublebacker arranged to operate in accordance with the invention; the disclosure however should be considered `as merely illustrative of the invention in its broader aspects.

In the drawings:

FIG. 1 is a longitudinal sectional view, largely schematic, taken through a doublebacking machine equipped to function in accordance with the invention;

FIG. 2 is a section on line 2-2 of FIG.1 looking in the direction of the arrows;

FIG. 3 is a diagram showing schematically, electrical circuits appropriate for controlling spray apparatus of the character shown in FIGS. 1 and 2.

The invention is shown in FIG. 1 as applied to a doublebacking machine having at its entrance end, a guide pulley 1 for the upper conveyor belt 2 which runs throughout the full length of themachine, a drive pulley 3 for such belt Patented June c, 1961 fice being provided at the delivery end of the machine. As indicated at the right of FIG. l a single faced corrugated paper web 4 is fed into the entrance end of the machine, the exposed peaks of the corrugations being coated with adhesive as is usual in the art, and at the entrance end of the machine, the web 4 is brought into contact with a traveling facing sheet 5 which runs over a guide roll 6 and an apron 7 located at the entrance end of the machine. In the initial section of the machine the corrugated paperboard thus formed is fed progressively by the belt 2 over a series of heating plates 8 which aid in setting the adhesive and drying out the material, the plates 8, apron 7 and roll 6 being usually steam heated. After passing the heating plates above mentioned, the paperboard passes in between the above described upper conveyor belt 2, and a lower conveyor belt 9 which is shown -at the left of FIG. l `as passing yaround a drive pulley 10, so that a continuous length of corrugated paperboard passes out at the delivery end of the machine. The machine as thus far described may be understood as of known or any appropriate form.

In the normal range of production speeds, the heat to which the material is subjected in passing through the machine, is sufficient to set the adhesive and dry out the board without injury to the latter due to overheating, and in accordance with the present invention, under conditions where the feed of the material through the machine is temporarily slowed down or stopped, the moisture content of the material being thus subjected to the heat of plates 8 for `an abnormally long period, is increased sufficiently to avoid overheating of the material under the above conditions.

As shown in FiG. 1, a spray apparatus may be employed, which has a header 11 extending transversely across the machine adjacent lthe path of travel of the material and located at ya point Where the moisture content thereof is to be increased, the header 11 being provided with a series of perforated nozzles 12 which distribute the moisture in the form of tine sprays over the surface of the material yas it travels past the header 11. The header 11 may be supplied with hot water by a pipe 13 which extends through one of the side frames 14 of the machine.

The header 11 shown in FIG. 2 may be understood as interposed between the rst and second steam plates 8 which appear at the entrance end of the machine as shown in FIG. l, `and similar headers as shown at 11A Land 11B in FIG. 2, may be provided at points spaced along the heating section of the machine. Also a similar header 11C may be provided `adjacent the apron 7, to meisten the under surface of the facing sheet 5 als it enters the machine, which surface will be directly exposed to the heater plates S while the material is in the machine. A similar header 11D is also shown at the right of FIG. l, in position to apply moisture to the upper exposed surface of the single faced paper web 4 as the latter passes into the machine.

As shown at the left of FIG. 2, water for the above purposes may be supplied through a pipe 15 into which steam is injected from a pipe 16 to heat the water, a pipe 17 running along the machine being provided to feed the various pipes 13 above mentioned. As later described in greater detail, the ow of water for the above purposes may be turned on and off by a valve 18.

FIG. 3 shows schematically an electrically controlled system for controlling the moisture supplied to the paperboard `for the above purposes. In FIG. 3 a direct current motor 19 is shown and should be understood as driving the conveyor belts 2 and 9 above mentioned, circuit to the motor 19 being opened and closed by a switch 20 to start and stop the feed of material through the machine, appropriate adjustment being provided to afford intermediate speeds of feed as is customary in the art. The motor 19 may be powered from any suitable source, as

for example the generator of a motor-generator set. FIG. 3 also shows a service circuit comprising the conductors 21, 22 and relays 23, 24 which control circuit to a coil 25 which should be understood as controlling the valve 18 previously mentioned. A brake 26 is also indicated schematically in FIG. 3, and should be understood as activated when switch 20 is opened, to bring the conveyor belts '2 and 9 quickly to rest.

The relay 23 should be understood as being of the so-called voltage operated type, and adjusted to hold the circuit 21, 22 closed so long as the speed of feed as controlled by motor I9, exceeds for example 100 ft. per min. The relay 24 should be understood as set to open at Zero voltage, i.e. when motor 19 is at rest so that the material lies stationary in the machine. So llong as both of the relays 23 and 24 are closed as will be the case in the normal range of operating speeds of feed, circuit to the coil will be closed and the latter will hold the valve 1S closed. Thus under normal production speeds of feed no additional moisture will be supplied to the material passing through the machine, but when the rate of feed drops down below 100 ft. per min., relay 23 will open to deenergize the coil 25 and thereby open the valve 18 to supply extra moisture to the material passing through the heating section of the machine which includes the steam plates 8. So long as the machine continues running at abnormally low speed the supply of additional moisture will continue, but if the machine is stopped, relay 24 will open to complete circuit to the coil 25 through the conductors 27, 2S and 29, thereby closing valve 18 to cut off the moisture sprays, and at the same time energizing the brake mechanism 26 to stop the feed of material through the machine.

When switch 20 is closed to start up the machine, relay 24 will close but so long as the relay 23 remains open, all circuits leading through the coil 25 Will be open and therefore the valve 18 will be open. In other Words while the machine is starting up and until a rate of feed of say 100 ft. per min. is reached, the moisture spray apparatus will be in action to protect the material against over-heating while travelling slowly past the steam plates 8. When the feed attains a higher speed relay 23 will close, thereby closing circuit to the coil 25 through both relays to cut oif the moisture sprays so that the latter remain inactive when the rate of yfeed is within the normal production range.

In the normal course of production, the machine is stopped or run at abnormally low speed only occasional-ly for short periods measured in seconds, as needed while the mechanisms to which the continuous length of paperboard passes after leaving the doublebacker, are being readjusted to produce blanks of different dimensions. Such mechanisms have long been provided with devices for resetting them to different dimensions, which devices come into action upon the completion of a run of blanks of some other size. Such adjustments may be quickly made and therefore length of material to which extra moisture need be suplied to avoid overheating, is short. In other words the extra moisture added to the material in accordance with the present invention, need only be that which will protect against overheating the length of material which lies stationary in the heating section of the ma-V chine or passes very slowly therethrough, for a period of time measured in seconds. The extra moisture thus added to the material during the above mentioned short periods, is kept below an amount which would result in the production of incompletely dried out corrugated paperboard. The spray apparatus 11B is preferably so positioned that the portion of the paperboard moistened thereby will approximately reach the end of the heating zone constituted by the steam plates 8, by the time when brake 26 halts the travel of the paperboard, to the end that the portion of the paperboard which lies stationary in the heating zone shall be adequately moistened, without excessively moistening the portion of the paperboard which 4 e has passed beyond the heating zone before the machine stops.

I claim:

l. A double backing machine of the character described, having a web heating section, means for guiding a single faced corrugated paper web to pass to said heating section, means for applying adhesive to the exposed peaks of the corrugations of such web when travelling toward said heating section, means for guiding a facing sheet into contact with said peaks when travelling to said heating section to form partially completed corrugated paperboard, means adjustable as to operating speed for feeding said partially completed paperboard through said heating section, apparatus for increasing the moisture content of said partially completed paperboard, and means responsive to changes in speed of said feeding means for cutting said apparatus into action when said feeding means is operating at low speed and cutting said apparatus out of action when said lfeeding means is adjusted to operate at higher speed.

2. A double backing machine of the character described, having a web heating section, means for guiding a single faced corrugated paper web to pass to said heating section, means for applying adhesive to the exposed peaks of the currugations of such web when travelling toward said heating section, means for guiding a facing sheet into contact with said peaks when travelling to said heating section to form partially completed corrugated paperboard, means adjustable as to operating speed for feeding said partially completed paperboard through said heating section, apparatus for increasing the moisture content of said partially completed paperboard, and means responsive to changes in speed of said `feeding means for cutting said apparatus into action when said feeding means is operating at Llow speed and cutting said apparatus out of action when said feeding means is stopped.

3. A double backing machine of the character described, having a web heating section, means for guiding a single faced corrugated paper web to pass to said heating section, means for lapplying adhesive to the exposed peaks of the corrugations of such web when travelling toward said heating section, means for guiding a facing sheet-into contact with said peaks when travelling to said heating section to form partially completed corrugated paperboard, means adjustable as to operating speed for feeding said partially completed paperboard through said heating section, apparatus for increasing lthe moisture content of said partially completed paperboard, and means responsive to changes in speed of said feeding means for rendering said apparatus inactive in the normal range of production speeds of feed, but cutting said apparatus into action when said feeding means is operating at speeds less than said normal range, and cutting said apparatus out of action when said feeding means is stopped.

4. A double backing machine of the character described, having a web heating section, means for guiding a single lfaced corrugated paper web to pass to said heating section, means for applying adhesive to the exposed peaks of the corrugations of such web when travelling toward said heating section, means for guiding a facing sheet into contact with said peaks when travelling to said heating section to form partially completed corrugated paperboard, means adjustable as to operating speed for feeding said partially completed paperboard through said heating section, yapparatus for increasing the moisture content of said partially completed paperboard, and means responsive to changes in speed of said feeding means for cutting said apparatus into action when said feeding means is operating at low speed and cutting said apparatus out of action when said feeding means is adjusted to operate at higher speed, said moisture increasing apparatus having a spray pipe disposed transversely of the path of travel of said facing sheet, in position to direct moisture onto the surface of said sheet.

5, A double backing machine of the character described, having a web heating section, means for guiding a single `faced corrugated paper web to pass to said heating section, means for applying adhesive to the exposed peaks of the corrugations of such web when travelling toward said heating section, means for guiding a facing sheet into contact with said peaks when travelling to said heating section to form partially completed corrugated paperboard, means adjustable as to operating speed for feeding said partially completed paperboard through said heating section, apparatus for increasing the moisture content of said partially completed paperboard, and means responsive to changes in speed of said lfeeding means for cutting said apparatus into action when said feeding means is operating at low speed and cutting said apparatus out of action when said feeding means is adjusted to operate at higher speed, said moisture increasing apparatus having a spray pipe disposed transversely of the path of travel of said partially completed paperboard While passing through said heating section, in position to direct moisture onto the surface of said partially completed paperboard while so passing through said heating section.

6. The method of producing corrugated paperboard which includes feeding a single faced corrugated paper web into a doublebacker, applying adhesive to the exposed peaks of the corrugations of such web while traveling toward the doublebacker, feeding a facing sheet into the doublebacker in contact with said peaks to form partially completed corrugated paperboard, applying heat to said partially completed paperboard While passing through said doublebacker, altering the speed of travel of said partially completed paperboard through the doublebacker between zero and production speed, and subjecting at least one of the constituents of said partially completed corrugated paperboard to a moisture-laden medium to increase the moisture content of the portion of the partially completed corrugated paperboard which is being subjected to heat as aforesaid, when the speed of feed of said partially completed board through the doublebacker is lower than a normal production rate, and cutting said moisture-laden medium out of action when normal production speed is resumed.

7. The method of producing corrugated paperboard which includes feeding a single faced corrugated paper web into a doublebacker, applying adhesive to the exposed peaks of the corrugations of such web while traveling toward the doublebacker, feeding a facing sheet into the doublebacker in contact with said peaks to form partially completed corrugated paperboard, applying heat to said partially completed paperboard while passing through said doublebacker, altering the speed `of travel of said partially completed paperboard through the doublebacker between zero and production speed, and subjecting at least one of the constituents of said partially completed corrugated paperboard to a moisture-laden medium to increase the moisture content of the portion of the partially completed corrugated paperboard which is being subjected to heat as aforesaid, when the speed of feed of said partially completed board through the doublebacker is lower than a normal production rate, and cutting said moisture-laden medium out of action when the speed of feed is reduced to zero.

8. A double backing machine of the character described, having a web heating section, means for guiding a single faced corrugated paper web to pass to said heating section, means for applying adhesive to the exposed peaks of the corrugations of such web when travelling toward said heating section, means for guiding a facing sheet into contact with said peaks when travelling to said heating section to form partially completed corrugated paperboard, means adjustable as to operating speed for feeding said partially completed paperboard through said heating section, apparatus for increasing the moisture content of said partially completed paperboard, and means responsive to changes in speed of said feeding means for adjusting said apparatus to increase the moisture content of the partially completed paperboard when said feeding means is operating at low speed.

References Cited in the le of this patent UNITED STATES PATENTS 1,115,265 Weis Oct. 27, 1914 1,142,409 Ferres .Tune 8, 1915 1,179,941 Langston Apr. 18, 1916 1,327,158 Hawkins Ian. 6, 1920 1,822,005 Broughton Sept. 8, 1931 1,924,100 Barker Aug. 29, 1933 2,231,457 Stephen Feb. 11, 1941 2,236,056 Grimm Mar. 25, 1941 2,288,129 Feldhausen et a1. June 30, 1942 2,309,728 Goettsch Feb. 2, 1943 2,365,352 Mott Dec. 19, 1944 2,414,891 Oen Feb. 19, 1944 2,587,273 Aquilla Feb. 26, 1952 2,800,725 Holes --.w July 30, 1957

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