US3669064A

US3669064A - Apparatus for impregnating corrugated cardboard

Info

Publication number: US3669064A
Application number: US9581A
Authority: US
Inventors: Walther J Hoelzinger; Johann Wenninger; Walter Mayer; Karl Zoegernitz; Hermann Schroetter; Werner Braun
Original assignee: Boise Cascade Corp
Current assignee: Officemax Inc
Priority date: 1970-02-09
Filing date: 1970-02-09
Publication date: 1972-06-13
Anticipated expiration: 1989-06-13
Also published as: FI53415B; ES385347A1; DK143541C; RO62113A; YU36270B; NO131613B; SU384243A3; IL35410A; NO131613C; DE2105297C3; ZA707025B; SE369589B; FR2080338A5; DE2105297B2; AT310546B; CA944552A; PL83024B1; OA04028A; NL7014932A; FI53415C

Abstract

Apparatus for impregnating longitudinally travelling corrugated board having transversely extending flutes, including suction means arranged adjacent one longitudinal edge of the board for establishing a vacuum in the flutes to draw a material, such as an impregnant, therethrough. The invention is characterized by the provision of retaining means for preventing undesirable lateral displacement of the board in the direction of the suction means. In the preferred embodiment, the retaining means comprise longitudinally extending endless belt means responsive to the vacuum established in the flutes for clamping the moving board against lateral displacement without crushing the flutes or causing damage to the board. Preferably the endless belt means are provided with longitudinal ribs that extend within corresponding grooves in the rollers upon which the belts are mounted, thereby preventing lateral movement of the belt meansand the board-relative to the rollers. In accordance with an important feature of the invention, flow control means are provided for accurately controlling the speed and/or extent of longitudinal penetration of the material through the flutes.

Description

tates atent Hoelzinger et al. I

[ 51 June 13, 1972 CORRUGATED CARDBOARD [72] lnventorsz Walther J. Hoelzinger; Johann Wenninger; Walter Mayer; Karl Zoegernltz; Hermann Schroetter; Werner Braun, all of Vienna, Austria [73] Assignee: Boise Cascade Corporation, Boise, Idaho [22] Filed: Feb. 9, 1970 [21] App]. No.: 9,581

[52] US. Cl ..1l8/39, 118/50, 118/65, v 118/326, 156/210 [51] Int. Cl. ..B05b 15/04, B31f 1/20 [58] Field of Search ..118/39, 49,50, 64, 65, 302, 118/324, 326; 156/210, 473; 239/138 5 6] References Cited UNITED STATES PATENTS 1,592,824 7/1926 1,880,065 9/1932' 2,191,827 2/1940 2,324,787 7/l943 2,698,260 12/1954 2,826,236 3/1958 2,955,330 10/1960 3,343,977 9/1967 ...118/326 X 3,389,437 6/1968 Andreani ..19/252 FOREIGN PATENTS OR APPLICATIONS 390,462 7/1908 France ..239/1 38 Primary Eraminer-Mervin Stein Attorney-Lawrence E. Laubscher [5 7] ABSTRACT Apparatus for impregnating longitudinally travelling corrugated board having transversely extending flutes, including suction means arranged adjacent one longitudinal edge of the board for establishing a vacuum in the flutes to draw a material, such as an impregnant, therethrough. The invention is characterized by the provision of retaining means for preventing undesirable lateral displacement of the board in the direction of thesuction means. In the preferred embodiment, the retaining means comprise longitudinally extending endless belt means responsive to the vacuum established in the flutes for clamping the moving board against lateral displacement without crushing the flutes or causing damage to the board. Preferably the endless belt means are provided with longitudinal ribs that extend within corresponding grooves in the rollers upon which the belts are mounted, thereby preventing lateral movement of the belt means-and the board--relative to the rollers. In accordance with an important feature of the invention, flow control means are provided for accurately controlling the speed and/or extent of longitudinal penetration of the-material through the flutes.

21 Claims, 17 Drawing Figures PATENTEBJuu 13 I972 3,669,064

SHEET 1 or 6 4 1 6 w 3 m r N. NE 1 INVENTORS Walther J. Hoelzinger Johann Wenninger Walter Mayer Karl Zoegernitz Hermann SchroeHer ATTORNEY Werner Brclun Supply PATENTEUJuu 13 m2 Ho? Wax SHEET 8 0F 6 S p y Fig. /5

Hem

v Exchanger Means Hot Wax 1NVENTOR5 fdmm ATTORNEY APPARATUS FOR IMPREGNATING CORRUGATED CARDBOARD In the patented prior art, various static and dynamic methods and apparatus have been proposed for impregnating corrugated board with a material having waterproofing, structurally reinforcing, or other characteristic. For example, the dipping of corrugated board in an impregnating bath is disclosed in the'Wilkins US. Pat. No. 3,402,068, among others. In the Russell et al. U.S. Pat. No. 3,310,363, it is proposed to pass horizontally arranged corrugated board through a pres surized impregnating chamber, and in the patents to Gjesdal US. Pat. No. 3,343,977 and Fairchild US; Pat. No. 1,592,824, the precut corrugated board'is arranged vertically about its longitudinal edge to effect downward flow, by gravity, of the impregnant through the vertical flutes (with or without the aid of pressure spraying and/or suction).

From a practical standpoint, it is desirable to impregnate the corrugated board as it is actually being formed from paper rolls by conventional corrugator equipment. In the prior U.S. patent application Ser. No. 763,268 filed Sept. 27, 1968, in the names of Werner Achermann et al. (and assigned to the same assignee as the present invention), it was proposed to impregnate longitudinally travelling horizontally arranged board by the use of vacuum or suction means that draw the impregnating materialthrough the transversely arranged flutes of the board. Owing to the relatively high linear velocity production rates of the board (which are on the order of 300 feet perminute or more), it is rather difficult to accurately impregnate the board with an exact quantity of impregnant materialper foot of board. This relatively high velocity rules out the majority of the previously proposed impregnating methods and apparatus, leaving the vacuum or suction impregnation concept as the most feasible process for commercial utilization and development. I

'A second major consideration in the development of the impregnation equipment is the adaptability of the apparatus for installation on, existing corrugator systems. In practice, the preferred location of theimpregnating equipment in an existing corrugator system is the rather limited space between the order cut-off shear (which is operated only periodically at the end of a given order run) and the Triplex means for longitudinally scoring and slitting the board. Since the space between these two units is normally rather limited (on the order of 10 to 12 feet, for example), another critical design limitation is imposed on the impregnating equipment which, together with the high linear velocity of the board, further impairs the impregnation process. More particularly, in order to draw the impregnating material completely through the flutes during the relatively short time that the travelling board is within the impregnating station, a rather high vacuum must necessarily be established within the flutes. This high vacuum would normally tend to cause the travelling board to be drawn laterally toward the suction means arranged adjacent one longitudinal edge of the board, with the undesirable result that the ends of the flutes would be closed to prevent air or impregnant materia] from being drawn therethrough. Moreover, the lateral displacement of the board would produce undesirable skewing, buckling or jamming of the board as it is conveyed toward the Triplex scoring and slitting means.

Another important consideration is the problem of supplying the impregnatingmaterial to the flutes with such a consistency that the impregnant will be so drawn through the flutes as to effect uniform impregnation completely across the board without the quantity of the impregnant being uneconomically excessive. Thus, in the case of a hot wax impregnant, it is desirable to accurately control the impregnantto-air ratio, so that the cost of the wax will be reduced, and the outer surfaces of the liners will have a desired surface condition. In this regard, by appropriate control of the impregnant, a totally impregnated board condition may be achieved, or in the alternative, by reducing the wax supply, the outer surfaces of the. liners maybe maintained wax-free for printing and/or gluing, or for coating with inks or other materials. Accordingly, it is necessary to provide a reliable control means for regulating the flow of the impregnating material into the transporting air stream.

Finally, in order to retard the outward wicking of the wax and to reduce the heat of the corrugated board and thereby facilitate handling at the take-off station, it is desirable to apply to the upper and/or lower surfaces of the board a temporary coating of water, ink or other wicking retardant, by spraying in the form of a mist, by sponging, or the like. On the other hand, for achieving acceptable impregnation of the longitudinal edge portion of the board adjacent the suction means, sufficient impregnating material must be introduced into the flutes to uniformly cover the interior of the board throughout its width, taking into account the inherent increase in the velocity of the impregnant or other material as it approaches the suction ends of the flutes. With the above and other considerations in mind, the present invention was developed to provide an improved board impregnating apparatus that avoids the drawbacks of the known impregnating equipment. The primary object of the present invention is to provide improved apparatus for impregnating corrugated board as it is actually being manufactured on conventional corrugator apparatus, including an impregnating station of minimum length adapted for insertion subsequent to the heating and cooling stations of the corrugator, and preferably between the order cut-off shear means and the Triplex scoring and slitting means. The impregnating station includes impregnant supply means for supplying impregnant material adjacent one longitudinal edge of the board, and suction means adjacent the other longitudinal edge for establishing a vacuum within the flutes to draw the impregnant therethrough. The presentinvention is characterized by the provision of retaining means for preventing the travelling high speed board from being drawn laterally 0E line in the direction of'the suction means by the high vacuum established in the flutes.

A more specific object of the invention is to provide vacuum-responsive clamping means for clamping the travelling board to a stationary frame arranged transversely between the impregnant supply and the suction means, use being made of longitudinally extending endless belt means driven at the same or slightly greater linear velocity as the board. Preferably the frame is mounted for displacement from the operative impregnating position to an inoperative storage or servicing position when not in use. In order to prevent lateral displacement of the endless belt means relative to the rollers upon which they are mounted, the belt means are provided with longitudinal ribs that extend within corresponding grooves contained in the rollers. In accordance with an important feature of the invention, means are provided for accurately adjusting the angles of the roller axes relative to the frame to further prevent the board from becoming laterally displaced from or skewed relative to its longitudinal axis of travel.

A further object of the invention is to provide impregnating apparatus including means for laterally adjusting the impregnant supply means and the suction means relative to the longitudinal edges of the corrugated board, thereby to accommodate board of different widths. In one embodiment, the impregnant supply means and the suction means include channel members connected for lateral adjustment relative to the frame. In a second embodiment, the impregnant supply means is combined with a heat exchanger arranged for lateral adjustment adjacent one edge of the board, and the suction means is combined with impregnant separator means arranged for lateral adjustment adjacent the other edge of the board.

Another object of the present invention is to provide impregnant supply means including a channel member arranged longitudinally adjacent one edge of the travelling board and including a series of longitudinally spaced first outlets for supplying, via adjustable flow control means, an impregnant of desired consistancy adjacent one end of the flutes, and a subsequent second series of second outlets for supplying to the flutes, via adjustable flow control means, hot air or other agent. Furthermore, the suction means includes a similar channel member arranged at the other longitudinal edge, said suction channel containing a series of suction inlets connected, via adjustable flow regulating means, with a vacuum source. In the case of a wax impregnant, heating means are provided to assure an even distribution of the material throughout the lengths of the flutes. By appropriate control of the various regulating means (including valve adjustment, nozzle configuration and/or dimensions, supply pressures and the like), proper uniform impregnation of the flutes throughout their length may be achieved in a positive manner.

Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in the light of the accompanying drawing, in which:

FIG. 1 is a diagrammatic view of the installation of the impregnation apparatus of the present invention in a conventional corrugator system;

FIG. 1a is a detailed sectional view of a single-wall or double-faced corrugated board embodiment produced by the system of FIG. 1; I

FIG. 2 is a top plan view of the impregnation station of FIG.

FIGS. 3 and 4 are sectional views taken along lines 33 and 44, respectively, of FIG. 2;

FIG. 5 is a detailed sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a detailed end view of the roller adjusting means of FIG. 5;

FIG. 7 is a detailed top plan view of the impregnating supply and the suction means, with the endless belt retaining means removed for clarity;

FIGS. 8-10 are sectional views taken along lines 88, 9-9 and 10-10, respectively, in FIG. 7;

FIG, 11 is a detailed plan view of the impregnation sections of the impregnant supply channel means of FIG. 7;

FIG. 12 is a detailed view of the impregnant flow regulating means of FIG. 11;

FIG. 13 illustrates diagrammatically a second embodiment of the invention wherein the impregnant supply means and the suction means are arranged for movement independent of the retaining means frame;

FIG. 14 illustrates diagrammatically a wax curtain impregnant supply modification; and

FIGS. 15 and 16 are modifications of the means for mixing the impregnant material with the transporting air to effect a desired impregnant-to-air ratio.

Referring first to FIGS. 1 and 1a, the conventional corrugator apparatus includes a plurality of

single facer units

2, 4 and 6 and a roll stand 8 for supplying material to the double facer 10 via the preheater l2 and the glue station 14. In the illustrated system for producing the corrugated board of FIG. la, the

single facers

4 and 6 are temporarily disconnected reserves, and the single facer 2 forms from paper rolls the laminate including the fibrous layer 2a with serpentine layer 2b secured thereto. The roll stand 8 provides the bottom surface layer 8a, all of said layers being pressed together for permanent adhesive connection by the double facer 10. The corrugated board 16 then passes successively through the heating and

cooling sections

18 and 20, the intermittently operable order cut-off shear 22, the Triplex longitudinal slitting and scoring means 24, the rotary cut-off means 26, and the severed section take-off means 28. As is conventional in the art, all of the aforementioned corrugator components are driven in synchronism.

In accordance with the present invention, there is provided in the limited space between the order cut-off shear 22 and the Triplex slitter-scorer 24 an impregnating station for impregnating the traverse flutes of the longitudinally travelling horizontally arranged board with a suitable impregnant material affording waterproofing, fireproofing, structural reinforcing, odorizing, insulating, or other characteristic, such as bitumen, paraffin, waterglass, synthetic plastic resin, glue, paraffinbitumenized emulsion, artificial resin wax mixture, liquid synthetic materials, synthetic plastic foaming materials,

artificial resins, silicon, sodium silicate solution, alkali metal silicate, vinyl resin, and the like. Impregnant supply means 32 are provided for supplying the impregnant adjacent one longitudinal edge of the board, and suction means including a wax separator 34 and vacuum pump means 36 are provided adjacent the other edge for establishing a vacuum in the transverse flutes to draw the impregnant material completely therethrough.

Referring now more particularly to FIGS. 24, the impregnating station includes a frame 40 having at each end a pin 42 that extends from end plate 43 within a corresponding vertical guide slot in the stationary vertical pillars 44. At its lower end the frame is supported by the cooperation between foot rollers 46 and stationary cam support means 48, the frame being displaceable from the illustrated operative position to an elevated inoperable storage or servicing position illustrated in phantom in FIG. 4. The end plates 43 are rigidly connected by transverse frame cross members 50.

Journalled at each end in bearing means supported by the frame end plates 43 are a pair of

upper rollers

52, 54 that support the longitudinally extending upper endless belt 56 with its lower run adjacent the upper surface of the board 16. Similarly journalled at each end in the frame are

lower rollers

60, 62 and 64 that support the longitudinally extending lower endless belt 66 with its horizontal upper run adjacent the lower surface of the board. The upper and lower belts have such a width relative to the width of the board that when the vacuum is established within the board flutes as will be described in greater detail below, the upper and lower belts are drawn together by suction to tightly clamp the board 16 therebetween, whereby lateral displacement of the board relative to the frame is positively prevented. As shown in FIGS. 2 and 3, the widths of the endless belts are less than the width of the board. In order to prevent lateral displacement of the endless belts relative to the rollers, the belts are provided on their inner surfaces with continuous longitudinal rib portions 56a and 66a, respectively, that are received in corresponding grooves contained in the rollers, as shown in FIG. 5. While in the illustrated embodiment, the use of V-belt ribs has been described, it will be apparent to those skilled in the art that other retaining means, such as guide rolls, can be used equally well.

As shown in FIG. 4, the lower endless belt 66 is driven by the main corrugator drive means 30 via reduction gearing means 70 and sprocket chain 72, the linear speed of the horizontal upper run of the lower belt 66 being equal to or slightly greater than the linear velocity of the board. In accordance with an important feature of the invention, the rollers are provided with accurate adjusting means for causing the axes of the rollers to be exactly horizontal and normal to the longitudinal axis of the board, whereby skewing of the board during passage through the impregnating station is avoided. Referring to FIG. 6, it will be seen that longitudinal adjustment of the bearing pedestal 76 within the frame slide 78 is effected by the screw means 80, while longitudinal adjustment of the upper roll pedestal 82 in the bearing slide 84 is effected by the screw means 86. Vertical adjustment of each end of the upper roll is controlled by the upper screw adjusting means 88.

Slidably connected with the frame end plates 43 for lateral adjustment relative to the board are a pair of slide members to which are pivotally connected by pivot pins 92 an impregnant supply channel member 94 and a suction channel member 96, respectively, that extend longitudinally adjacent opposite edges of the board. The channel members are provided with

lateral extensions

94a, 96a that are received in corresponding guide slots contained in the forward and rear edges of the frame end plates 43, said lateral extensions serving with the slots to support the channel members for limited pivotal movement in a horizontal plane about their respective pivot axes 92. In order to laterally adjust the channel members relative to the frame to accommodate corrugated board of varying widths, and to control the pivotal orientation of the channel members about their pivot axes, there aresecured to the frame cross supports 50a that extend between the runs of the lower endless belt 66 four hydraulic piston-

cylinder motors

97, 98, 100 and 102. Upon the simultaneous extension and contraction of the hydraulic motor means, the spacing distance between the channel members may be increased and decreased,respectively.

Referring now to FIG. 7-11,- each of the impregnating supply and suction channel members comprises a plurality of longitudinal sections connected at adjacent ends by male pin and female recess means 106 (FIG. 11), andby rod means 108 extending longitudinally therethrough for bolting the sections together to form arigid assemblage. The impregnant supply channel 94 includes a first series of longitudinally spaced outlets 110 (FIG. 8) to which the impregnant of desiredconsistency is supplied from source 32 via heated conduits 112,

114 and 116 containing flow regulating means 120, 122 and 124, respectively, whereby the impregnant material is supplied adjacent one edge of the board. Furthermore, the impregnant supply channel includes a second series of longitudinally spaced outlets 130 (FIG. 9) to which hot air is supplied from source 132 via

conduits

134, 136, 138, 140 and 142 containing flow regulating means 144, 146, 148, 150 and 152,

v respectively. Finally, hot air is also supplied to the outlets 1 of the impregnating channel sections via

conduits

156, 158 and 160 containing flow regulating means 162, 164 and 166,

respectively. Similarly, the suction channel member 96 which defines the suction chamber 96c having a vertical rear wall 96a includes a series of longitudinally spaced inlets 170 FIG. 10) that are connected with the suction means 36 via

conduits

174, 176, 178, 180', 182 and 184 containing flow regulator means 186, 188, 190, 19 2, 194 and 196, respectively.

Passages

198 and 200 extend longitudinally through the supply and suction channels, respectively, for conducting a heating fluid such as steam through the sections to maintain the impregnating material in a heated condition. In the alternative, the channels may be heated by electrical heating means.

Referring now more particularly to FIG. 8, the impregnant supplying section 94a has aninlet 116a communicating with the conduit 116 to supply the-impregnant (for example, hot

wax in liquid or atomized form) to the outlet 110 via the rotatable flow control member 210 containing the transverse metering slot 212. As shown-in FIGS. 11 and 12, the control member 210 has an operating handle 214 that extends radially through a cover plate 216 to permit manual adjustment of the meterin position of the control member, and control over the quantity of impregnant admitted to the flutes. The impregnant is directed downwardly adjacent the feed lip 218, whereupon the impregnant is mixed with the air supplied via the converging passage 220 to produce, according to one embodiment, an impregnant/air dispersion. This hot air is withdrawn by suction fromthe air box section 94b of the channel member as shown in FIG. 8. In a similar manner, the air is withdrawn by suction from the air box chamber 940 ofthe impregnating channel section 94d as shown in FIG. 9. In order to seal the ends of the flutes that extend within each channel member, there is provided a longitudinally extending seal strip 224 that is biased downwardly into engagement with the upper surface of the board by the spring means 226, the edge of the board being supported by a layer 228 of synthetic plastic material. If desired, the seal means may-include means (such as rubber lips or brushes) at the ends of the channel members to further ,seal the ends of the .flutes from atmosphere. As will be apparent from a comparison of FIGS. 9 and 10, the suction channel sections are identical to the

air section

940 and 94d of the impregnation channel 94. In the case where the seal strip comprises a sheet of thin material, such as foil, it will automatically be sucked toward sealing engagement with the surface of the board, whereby the necessity of spring means equivalent to thespring means 226 is avoided.-

In order to prevent a greater concentration of the impregnant adjacent the supply end of the flutes than the suction end (which would normally occur because of the increase in speed of the impregnant as it moves toward the suction means), the various flow control devices in the impregnant, hot air and suction conduits, respectively, are adjusted as necessary. Thus, at the impregnant supply side of the board, the hot air is first introduced in the flutes via conduit 134 and valve means 144, whereupon impregnant is successively introduced into the flutes via

heated conduits

156, 158 and 160 as regulated by the adjusting means 162, 164 and 168. By appropriate regulation of these control means, the proper successive impregnant charges are introduced into the flutes, and the subsequent application of hot air via the

conduits

136, 138, 140 and 142 as controlledby the

valves

146, 148, 150 and 152 cooperates with the vacuum means .in drawing the impregnant through the flutes. For example,as the speed of the material increases, the air supply may be reduced by appropriate controlof the valve means to slow down the impregnant material as it traverses the board. Similarly, at the vacuum side, it may be desirable to have the first group of

regulators

186, 188 and 190 in a fully open condition to effect maximum suction effect, while the

successive controllers

192, 194 and 196 may be in a partially throttled condition to produce a reduced suction effect. Of course, the adjustment of the flow regulators for the hot air, suction and impregnation conduits would vary in accordance with the specific impregnant utilized, the linear speed, of the board, whether the board is of the single or double wall type, the width of the 7 board, the dimensions of the flutes, and so forth. The versatili' piston-cylinder motor means 224 and 226,

ty of impregnation afforded by the apparatus of the present invention, the possibility of impregnating the board at the high production velocity during standard production process, and the adaptability of the impregnation equipment for installation on existing corrugator systems are prime advantages afforded by the improved apparatus. Moreover, the apparatus affords such accurate control that no more wax is applied to the board than is necessary to effect the desired degree of impregnation. As contrasted to the known impregnatingprocedures of the patented prior art, any selected degree of saturation of the board may be achieved.

As shown in FIG. 7, the channel members are connected for pivotal movement about axes 92, whereby an additional control is presented for preventing wandering of the board. If desired, conventional edge sensing means (not shown) may be provided for operating the hydraulic

piston cylinder motors

97, 98, and 102 to accurately control the positions and orientations of the channel members relativeto the board. Referring now to FIG. '13, a modification of the separator apparatus is disclosed in which the channel members are mounted for movement independently of the frame, the impregnant supply channel being combined with heat exchanger means to form a unit 220, and the suction channel member being combined with the separator unit 222. These units may be mounted on rollers for lateral displacement of the board by respectively. The upper and lower endless belts 228; and 230 are carried by the frame 232 for retaining the board against lateral displacement during transport through the impregnating station. By combining the suction channel with the separator means, improved suction is achieved and the temperature of the wax in the separator may be more readily controlled for separation from the air prior to entry in the vacuum pump means. Similarly, by combining the impregnant supply means with the heat exchanger, a more uniform temperature of the wax may be effected.

Referring now to FIG. 14, there is shown diagrammatically a modification of the impregnant supply means for supplying adjacent the ends of the flutes a curtain of a wax/air dispersion from inlet 240 through outlet 242 via the flow regulator 244. When the board 16 is adjacent the transverse outlet 246, the vacuum established in the flutes by the suction means causes the wax/air curtain to be drawn into the flutes together with the hot air supplied via passage 248. Thisembodiment offers the advantage that the wax/air curtain may be continuously recycled, and will be drawn through the passage 246 only when the board is present, thereby affording an automatic cutoff.

In FIG. 15, there is illustrated another modification of the impregnant supply means, which modification is particularly suitable for use in the integral heat exchanger supply means of FIG. 13. In this embodiment, the hot wax is supplied to turbulence mixing chamber 260 via the heat exchanger means 262 of the unit 220 via air-less wax spray means including dispersion chamber 264 and the spray nozzle 266. Hot air is supplied to the turbulence mixing chamber in converging jets via

conduits

268 and 270 containing

control valves

272 and 274, respectively. The wax and hot air is thoroughly mixed owing to the turbulence in the chamber 260, and is drawn by suction from the chamber via outlet passage 276 by the vacuum established in the flutes of the corrugated board 278 travelling continuously thereby. In order to regulate the mixing of the air with the wax, the nozzle means 266 is axially displaceable (by conventional adjusting means, not shown) between the illustrated left-hand position and a right-hand position adjacent the inlet orifice of passage 276. Drain passage 280 is provided in communication with the bottom of the chamber 260 to drain the wax condensate therefrom. As shown in the modification illustrated diagrammatically in cross-section in FIG. 16, the turbulence mixing chamber 286 containing the wax spray nozzle 288 may be concentrically jacketed to define

chambers

290, 292 to which a hot fluid (such as steam or air) is supplied to maintain the wax-air mixture at a desirably high temperature. In the case one of the fluids is hot air, it may be discharged into the chamber via orifices so arranged as to enhance the turbulence mixing effect.

In certain instances, the provision of the upper endless belt may be omitted. For example, in the case of corrugated board that is to be coated with a material such as flexographic white ink, the coating layer itself serves as an impervious covering that is drawn toward the bottom belt by the vacuum established in the flutes.

In order to retain the gluability and printability surface characteristics of the board, it may be desirable to apply (by spraying, sponging or the like) to at least one exposed face of the board prior to impregnation a temporary coating of a liquid material, such as water.

Finally, by filling the flutes with a mixture of asphalt and wax, a foam that will form a rigid mass, or certain resins, the structural strength of the board is increased to such an extent that the impregnated board may be used as an interior or exterior construction material.

While in accordance with the provisions of the Patent Statutes the preferred form and embodiments of the invention have been illustrated and described, it will be apparent that various modifications and changes may be made without deviating from the inventive concept.

What is claimed is:

I. Apparatus for impregnating horizontally arranged corrugated board continuously supplied by corrugator apparatus at a uniform initial linear velocity, said board including a serpentine fibrous intermediate layer cooperating with at least one fibrous outer layer to define a succession of transversely extending flutes, comprising a. stationary impregnant supply means for supplying fluid impregnating material adjacent one longitudinal edge of said board;

b. stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; and

c. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including 1. a stationary frame extending transversely of the board between said impregnant supply means and said suction means; and

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame, said clamping means including a. longitudinally extending endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the belt is sucked by the vacuum in the flutes into clamping engagement with the board; and

b. drive means for driving the endless belt means at a velocity at least as great as said initial linear velocity.

2. Apparatus for impregnating longitudinally traveling corrugated board having a serpentine fibrous intermediate layer 5 defining with at least one outer layer a succession of transversely extending flutes, comprising a. corrugator apparatus for forming roll paper into corrugated board and for conveying the board at a uniform initial linear velocity; b. stationary impregnant supply means for supplying impregnating material adjacent one longitudinal edge of said board; c. stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; d. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including 1. a stationary frame extending transversely of the board between said impregnant supply means and said suction means; and

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame, said clamping means including longitudinally extending endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the belt is sucked by the vacuum in the flutes into clamping engagement with the board;

e. stationary means for longitudinally scoring and slitting the impregnated board into sections;

f. rotary cut-off means for severing the sections into given lengths,

g. and means for driving said endless belt means and said rotary cut-off means in synchronism with said board conveying means.

3. Apparatus as defined in claim 2, and further including support means for alternately supporting said frame at operative and inoperative positions, respectively, relative to said corrugator conveying means and said scoring and slitting means.

4. Apparatus for impregnating continuously traveling horizontally arranged corrugated board including a serpentine fibrous intermediate layer cooperating with at least one fibrous outer layer todefine a succession of transversely extending flutes, comprising a. stationary impregnant supply means for supplying fluid impregnating material adjacent one longitudinal edge of said board;

b; stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; and

2. clamping means Connected with said frame and operable in response to'the vacuum established in the flutes for clamping said board against lateral movement relative to said frame; and

d. means for adjusting each of said impregnant supply means and said suction means laterally of said corrugated board -to accommodate different widths of corrugated board stock.-

5. Apparatus for impregnating continuously traveling horizontally arranged corrugated board including a serpentine fibrous intermediate layer cooperating with at least one fibrous outer layer to define a succession of transversely extending flutes, comprising a. stationary impregnant supply means for supplying fluid impregnating material adjacent one longitudinal edge of said board, said impregnant supply means including 1. a source of fluid impregnating material;

2. a channel member extending longitudinally adjacent said one board edge, said channel member including a first series of longitudinally spaced first outlets arranged for communication with one end of the board flutes; and

3. a plurality of conduit means each containing adjustable flow regulating means for connecting said first outlets with said source, respectively; stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; and retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including 1. a stationary frame extending transversely of the board between said impregnant supply means and said suction means; and

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board againstlateral movement relative to said frame.

6. Apparatus for impregnating longitudinally traveling horizontally arranged corrugated board having a serpentine fibrous intermediate layer defining with at least one planar fibrous outer layer a succession of transversely extending flutes, comprising i a. a frame;

b. stationary suction means connected with said frame for defining a suction chamber having a rear wall portion adjacent and spaced from one longitudinal edge of said board to establish a vacuum in said flutes;

c. stationary impregnant supply means connected with said frame directly opposite said suction means for supplying fluid impregnating material adjacent the other longitudinal edge of said board, whereby saidfluid impregnating material is drawn by suction through the flutes to impregnate at least the internal portion of the board; and

cl. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction'means, said retaining means comprising longitudinally extending horizontal endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the beltis sucked by the vacuum in the flutes into clamping engagement with the board.

7. Apparatus as defined in claim 6, wherein the width of said endless belt means is less than the width of the board.

8. Apparatus as defined in claim 6, wherein said endless belt means comprises upper and lower endless belts having longitudinal runs adjacent the upper and lower surfaces of said board, respectively.

9. Apparatus as defined in claim 8, wherein at least one of said belts is impervious.

10. Apparatus as defined in claim 4, wherein each of said lateral adjustment means includes guide means slidably connected for lateral movement relative to said frame, and hydraulicpiston-cylinder means for laterally displacing said guide means relative to said frame.

11. Apparatus as defined in claim 10, wherein each of said impregnating supply means and said suction means includes a channel member extending. longitudinally adjacent opposite edges of the corrugated board, respectively; 7

and further including pivot means connecting each of said channel members with the corresponding guide member, respectively, for pivotal movement about an axis normal to the plane of the corrugated board.

12. Apparatus as defined in claim 5, wherein said impregnant supply channel member includessubsequent to said first series of outlets a second series of longitudinally spaced second outlets, and further including a plurality of conduit means each containing adjustable flowregulating means for supplying hot air to said second outlets, respectively.

13. Apparatus as defined in claim 12, wherein said suction means includes a channel member extending longitudinally adjacent the opposite edge of the cardboard, said suction channel member including a series of longitudinally spaced inlets arranged for communication with the other end of the board flutes;

said suction means including also a vacuum source, and a plurality of conduits each containing adjustable flow regulating means for connecting said channel inlets with said vacuum source.

14. Apparatus as defined in claim 13, wherein at least one of said channel members comprises a longitudinal series of sections, and means connecting said sections to form a rigid assembly.

15. Apparatus as defined in claim 14, wherein said channel section connecting means includes pin means extending longitudinally from one end of one section, the adjacent end of the next section containing corresponding recess means for receiving said pin means.

16. Apparatus as defined in claim 13, and further wherein each of said channel members includes seal means for sealing the ends of the flutes from the ambient atmosphere during passage of said flutes through the impregnation station.

17. Apparatus as defined in claim 13, and further including means for heating at least one of said channel members.

18. Apparatus as defined in claim 6, wherein said impregnant supply means includes means for mixing together controlled quantities of an impregnant and a transporting gaseous fluid.

19. Apparatus as defined in claim 18, wherein said impregnant supply means includes means defining a turbulence mixing chamber, spray nozzle means for introducing the impregnant into said chamber, and means for introducing hot air into said chamber, said chamber having an outlet adjacent one longitudinal edge of the board for supplying the impregnant/air mixture to the flutes.

20. Apparatus as defined in claim 19, wherein said spray nozzle means is axially adjustable relative to said chamber outlet.

21. Apparatus for impregnating longitudinally travelling horizontally arranged corrugated board having a serpentine fibrous intermediate layer cooperating with at least one planar fibrous outer layer to define a succession of transversely extending flutes, comprising a. a frame;

b. stationary suction means connected with said frame adjacent one longitudinal edge of said board to establish a vacuum in the flutes opposite thereto, said suction means including a suction channel member defining a longitudinally extending suction chamber partially receiving the adjacent edge portion of said board, said suction chamber having a rear wall portion adjacent and spaced from the adjacent edge extremity of said board;

d. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means.

Claims

1. Apparatus for impregnating horizontally arranged corrugated board continuously supplied by corrugator apparatus at a uniform initial linear velocity, said board including a serpentine fibrous intermediate layer cooperating with at least one fibrous outer layer to define a succession of transversely extending flutes, comprising a. stationary impregnant supply means for supplying fluid impregnating material adjacent one longitudinal edge of said board; b. stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; and c. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including 1. a stationary frame extending transversely of the board between said impregnant supply means and said suction means; and 2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame, said clamping means including a. longitudinally extending endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the belt is sucked by the vacuum in the flutes into clamping engagement with the board; and b. drive means for driving the endless belt means at a velocity at least as great as said initial linear velocity.

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame, said clamping means including a. longitudinally extending endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the belt is sucked by the vacuum in the flutes into clamping engagement with the board; and b. drive means for driving the endless belt means at a velocity at least as great as said initial linear velocity.

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame; and d. means for adjusting each of said impregnant supply means and said suction means laterally of said corrugated board to accommodate different widths of corrugated board stock.

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame.

2. Apparatus for impregnating longitudinally traveling corrugated board having a serpentine fibrous intermediate layer defining with at least one outer layer a succession of transversely extending flutes, comprising a. corrugator apparatus for forming roll paper into corrugated board and for conveying the board at a uniform initial linear velocity; b. stationary impregnant supply means for supplying impregnating material adjacent one longitudinal edge of said board; c. stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; d. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including

2. clamping means connected with said frame and operable in response to the vacuum established in the flutes for clamping said board against lateral movement relative to said frame, said clamping means including longitudinally extending endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the belt is sucked by the vacuum in the flutes into clamping engagement with the board; e. stationary means for longitudinally scoring and slitting the impregnated board into sections; f. rotary cut-off means for severing the sections into given lengths; g. and means for driving said endless belt means and said rotary cut-off means in synchronism with said board conveying means.

3. a plurality of conduit means each containing adjustable flow regulating means for connecting said first outlets with said source, respectively; b. stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; and c. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including

4. Apparatus for impregnating continuously traveling horizontally arranged corrugated board including a serpentine fibrous intermediate layer cooperating with at least one fibrous outer layer to define a succession of transversely extending flutes, comprising a. stationary impregnant supply means for supplying fluid impregnating material adjacent one longitudinal edge of said board; b. stationary suction means arranged adjacent the other longitudinal edge of said board for establishing a vacuum in said flutes to draw the impregnating material therethrough; and c. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means including

5. Apparatus for impregnating continuously traveling horizontally arranged corrugated board including a serpentine fibrous intermediate layer cooperating with at least one fibrous outer layer to define a succession of transversely extending flutes, comprising a. staTionary impregnant supply means for supplying fluid impregnating material adjacent one longitudinal edge of said board, said impregnant supply means including

6. Apparatus for impregnating longitudinally traveling horizontally arranged corrugated board having a serpentine fibrous intermediate layer defining with at least one planar fibrous outer layer a succession of transversely extending flutes, comprising a. a frame; b. stationary suction means connected with said frame for defining a suction chamber having a rear wall portion adjacent and spaced from one longitudinal edge of said board to establish a vacuum in said flutes; c. stationary impregnant supply means connected with said frame directly opposite said suction means for supplying fluid impregnating material adjacent the other longitudinal edge of said board, whereby said fluid impregnating material is drawn by suction through the flutes to impregnate at least the internal portion of the board; and d. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means, said retaining means comprising longitudinally extending horizontal endless belt means adjacent at least one of the upper and lower surfaces of the board, said endless belt means having such a width relative to the width of the board that the belt is sucked by the vacuum in the flutes into clamping engagement with the board.

10. Apparatus as defined in claim 4, wherein each of said lateral adjustment means includes guide means slidably connected for lateral movement relative to said frame, and hydraulic piston-cylinder means for laterally displacing said guide means relative to said frame.

11. Apparatus as defined in claim 10, wherein each of said impregnating supply means and said suction means includes a channel member extending longitudinally adjacent opposite edges of the corrugated board, respectively; and further including pivot means connecting each of said channel members with the corresponding guide member, respectively, for pivotal movement about an axis normal to the plane of the corrugated board.

12. Apparatus as defined in claim 5, wherein said impregnant supply channel member includes subsequent to said first series of outlets a second series of longitudinally spaced second outlets, and further including a plUrality of conduit means each containing adjustable flow regulating means for supplying hot air to said second outlets, respectively.

13. Apparatus as defined in claim 12, wherein said suction means includes a channel member extending longitudinally adjacent the opposite edge of the cardboard, said suction channel member including a series of longitudinally spaced inlets arranged for communication with the other end of the board flutes; said suction means including also a vacuum source, and a plurality of conduits each containing adjustable flow regulating means for connecting said channel inlets with said vacuum source.

21. Apparatus for impregnating longitudinally travelling horizontally arranged corrugated board having a serpentine fibrous intermediate layer cooperating with at least one planar fibrous outer layer to define a succession of transversely extending flutes, comprising a. a frame; b. stationary suction means connected with said frame adjacent one longitudinal edge of said board to establish a vacuum in the flutes opposite thereto, said suction means including a suction channel member defining a longitudinally extending suction chamber partially receiving the adjacent edge portion of said board, said suction chamber having a rear wall portion adjacent and spaced from the adjacent edge extremity of said board; c. stationary impregnant supply means connected with said frame directly opposite said suction means for supplying fluid impregnating material adjacent the other longitudinal edge of said board, whereby said fluid impregnating material is drawn by suction through the flutes to impregnate at least the internal portion of the board; and d. retaining means for preventing lateral displacement of said board in the direction of said suction means during passage of said board between said supply means and said suction means.