Note: Descriptions are shown in the official language in which they were submitted.
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This invention concerns an apparatus and technique for manu-
facturing a laminar composite of two or more adhesively bonded layers of
sheet material, one of which has a corrugated surface contour at the inter-
face between the layers. The composite may, for example, comprise two or
more adhesively bonded layers of a wood fiber or pulp sheet material, such
as two or more layers of the paper-like material from which corrugated con-
tainers are made. The term "corrugated" is synonymous with a surface con-
tour in which there are alternate, straight, parallel ridges and grooves
that extend in serial array across one dimension or direction of the surface.
Ordinarily, the ridges and grooves are also substantially sinusoidally con- -
toured in this direction, but in the broader context of the invention, they ~-
may be formed otherwise, as shall be apparent from the description of the
invention which follows hereinafter.
As indicated, the invention is especially applicable to the manu-
facture of corrugated paper products. In the paper industry, these paper
products are commonly known as "corrugated board", and they each comprise
a core layer having a corrugated
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1 body configuration, and at least one other, but more often two
2 other layers which are sandwiched with the core layer and have
3 substantially planar body conflgurations. The three-layer product
is known as "double-faced board" and is commonly manufactured in
5 a machine which receives pliable webs of the board material and
6 passes them about and between a se~ies of power driven rolls
7 which operate, first, to impart a corrugated body configuration
8 to the corrugated layer web, and then in one or more subsequent
9 stages, to bond each of the respective planar layer webs to the
10 corrugated layer web. Each bonding operation .is accomplished by
11 applying adhesive to the ridges of the corrugated layer web, and
12 then contacting the respective planar layer web with the ridges
13 and pressing the two webs together until a bond is achieved
14 between the webs. Moreover, in the typ.ical machine, the corrugat:ing
15 operation and the initial bonding operation are closely integrated
16 in that the machine includes a pair of cooperating corrugating
17 rolls, and after the corrugated layer web has been passed about
18 one of thQ corrugating rolls and put through the nip between them
~9 to give it its corrugated body configuration, the web is temporarily
retained on the other corrugating roll, that is, on the web-
21 discharging roll, while the-adhesive is applied to the ridges of
22 the web and one of the planar layer webs is bonded to it as
23 indicatèd. Afterward, the composite is discharged from the roll
2~ and in a subsequent operation the other planar layer web is
25 bonded to the other side of the corrugated layer web, using the
26 same bonding technique but without the necessity for a back-up
27 roll for the corrugated layer web inasmuch as the corrugated body
28 configuration of the web is now fixed by the nature of t~e composite .
29 Heretofore, two techniques have been employed for
30 temporarily retaining the corrugated layer web on ehe web-
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1 ¦dischargin~ roll and in re~istry with the contour thereof. One
2 ¦technique has involved s-tationing a set of arcuate fingers at
3 ¦circumferentially outboard sites along the length of the roll to
~t ¦con~ine the web to the periphery of the roll while a mating,
5 ¦circumferentially-grooved applicator roll applies adhesive to the
6 ¦ridyes of the web. The other technique has involved building a
7 ¦set of arcua-te grooves into the periphery of the roll at circum-
8 ¦ferentially inboard sites along the length thereo, and applying
9 la vacuum to the grooves to hold the web on the roll while the
10 ¦adhesive is applied to the ridges of the same. Both techniques
11¦ have been operative to retain the web on the web-discharging
12¦ roll, but they have produced serious defects in the product. For
¦ example, the outboard finger technique has produced a defect in
1~¦ the fact that the fingers interrupt the continuity o the adhesive
15¦ applicator surEace, lengthwise thereof, and these interruptions
16¦ in turn produce interruptions in the glue lines that are formed
17¦ on the ridges of the corrugated layer web. Also, the fingers
18¦ produce indentations in the ridges at the sites of the interrup-
19¦ tions, and the indentations are aligned with one another on
2~ perpendiculars to the ridges so that the corrugated board product
21 incorporates lines of weakness about which it tends to buckle or
22¦ upture when it is subjected to compression lengthwise of the
23 idges. The character of these lines of weakness is illustrated
2~ in the accompanying drawings and will be described in greater
etail in connection with them.
~6 Furthermorej the outboard finger technique has produced
27 defect in the fact that the fingers do not hold the corrugated
~8 ayer web in strict registry with the contour of the web~discharging
29 oll. That is/ the web is able to "play" up and down in the
3~ ¦grooves of t oll, and in doing so, develops malformations in ¦
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1 its body configuration, and oE course, develops them even as the
2 first planar layer web and the corrugated layer web are being
3 ¦interfaced with one another. ~s a result, there is no assurance
¦that the corrugated layer of the product will have a true corrugated
5 ¦body configuration, nor any assurance -that it will have been
6 ¦properly interfaced with the first planar layer, and as a con-
7 ¦sequence, the industry must often accept in the product what are
8 ¦known as "high and low flutes" and "leaning flutes".
9 ¦ The inboard vacuum groove technique has produced a
10 ¦defect in the fact that-the vacuum grooves produce actual interrup-
ll ¦tions in the corrugated body configuration of the corrugated
12 ¦layer, and of course, this again is a defect which in~luences the
13¦ basic character of the product.
14¦ ~leretofore, moreover, the principal adhes`ive employed
15¦ in each of the bonding operations has been an adhesive such as
16¦ starch or sodium silicate which requires cutting with water or
17¦ some other dispersant which provides a vehicle whereby the adhesive
18¦ is satisfactorily dispersed for use, and in particular, suf~i-
l91 ciently dispersed to enable it to penetrate the sub-surface
20¦ fibers of the webs and achieve the necessary physical e~ect. In
21¦ order to achieve this effect, however, it has been necessary to
; 22 ¦ careully proportion the quantity of the dispersant in relatlon
231 to the quantity o~ the adhesive solid. Since the available
24 1 dispersant-cut adhesives comprise only about 25% solids, it has
2~1 aIso been necessary to lay down a thick line of the adhesive on
26¦ each ridge o~ the corrugated layer web, in order to assure tha~
27 an adequate amount of adhesive solids will remain for the bonding
28 e~fect a~ter the dispersant has evaporated.
29 Additionally, it has been necessary to maintain a line
30 thickn~ss con stent with th; mechanical to1erances o~ tbe adh~sive
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1 applica-tor equipment,-and the caliper differences o~ the web
2 materials. In particular, the equipment has almost always included
3 an applicator roll and a doctor roll with machined surfaces, and
4 the mechanical tolerances of these surfaces, together with the
5 usual caliper di~ferences between the web materials, have made it
6 imperative that the doctor roll leaves a film on the applicator
7 roll, which is sufficiently "thick" to assure that the roll in
8 turn will develop a line of adhesive on the ridges of the corrugated
9 layer web, which is sufficlently "thick" to assure that the
10 adhesive in turn will "bridge" between the webs when they are
11 contacted with one another. In short then, the bonding operation
12 as a whole has been quite delicate, since it has involved critical
13 limits ~or the web and adhesive materials, and a high degree of
14 precision in the adhesive applicator equipment.
For the foregoing reasons, the corrugated board indus-try
16 has long sought other laminating techniques and/or other adhesive
17 aterials. One area of investigation in recent years has been
18 the possibili ty of using the so-called hot melt or solid phase
19 adhesives in place of the old dispersant-cut adhesives just
2~ entioned. The solid phase adhesives need not be appreciably cut
21 by any dispersant, and have the advantage that their adhesive
22 echanism does not require penetrating the sub-surface fibers of
23 the webs, nor the application of heat to the composite. Also,
24 they can be used with a wide variety of substrates, even those
2~ which are relati~ely water impermeable. However, in spite of
2~ these advantages, they hava not been widely used in the industry
27 because of the mechanical problems which the industry has faced
28 in adapting them to the same equipment which was built for the
29 dispersant-cut adhesives.
30 ~ These latter problems have been twofold. First, in
31 order to lay down the minimum linè thickness required by the
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1 ¦e~xisting e~1uipment, it has been necessary to lay down far more
2 ¦solid phase adhesive -than is needed, and this in turn has proven
3 Ito be far too expensive in view of the relative cost of the solid
4 ¦phase adhesives. ~lso, this minimum line thickness has produced
51 a far larger "body" of adhesive across the interface between the
6 ¦webs than is actually desired. In fact, the body of adhesive has
71 been so great as to constitute virtually a third medium or stratum
8 ¦at each interface, and as such, has required a full structural
9¦ integrity of its own. Again, all of this has followed from the
10¦ fact that lhe existing equipment is designed and constructed to
11¦ lay down a line of adhesive having only approximately 25% solids,
12¦ hereas the new solid phase aclhesives run upward of ioo% solids.
13¦ Thus, the same line of solid phase adhesive produces a far larger
141 ody of set adhesive at each interace, and this body may in fact
15¦ e so great as to actually prevent the two layers from closely
16¦ contacting one another, as is desirable in any bond which is to
171 have a high structural integrity. On the other hand, all a-ttempts
18¦ to reduce the line thickness of the adhesive have met with little
19¦ or no success, because in each case, it has still been necessary
20¦ to lay down a thickness which can achieve a "bridge" between the
211 two webs, and this "bridge" in turn requires substantially the
22¦ same film thickness which was used previously with the dispersant-
231 cut adhesives.
241 Second, the new adhesives have also posed maintenance
251 problems in the equipment itself. Due to their higher solids
26¦ content, they are far more viscous and "gummy" in nature, and
271 this characteristic is particularly troublesome when outboard
28¦ fingers are employed, since the adhesive tends to collect on the
291 fingers, and in the finger grooves, and to cause clogging or
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jamming o~ the fingers in the ~rooves. The adhesive also tends to pull the
corrugated layer web off of the corrugating roll, due to the tackiness
generated by the adhesive between the applicator roll and the web.
In brief, the present invention eliminates the defects which the
prior art equipment produced in the product, while at the same time making
it possible to use the new solid phase adhesives in the process without the
foregoing problems.
According to one aspect of the invention there is provided a
method of laminating two or more layers of sheet material, one of which has
a corrugated surface thereon and the other of which has a planar surface
thereon, comprising passing the corrugated surface defining layer about a
carrier roll, generating a pressure differential across the carrier roll to `-
retain the corrugated surface defining layer thereon, juxtaposing a plain
cylindrically surfaced adhesive applicator roll adjacent the corrugated
surface defining layer, depositing adhesive on the plain cylindrical surface
of the applicator roll, forming the deposi1:ed adhesive into a series of
spaced parallel lines of adhesive which are disposed crosswise of the ridges
; o the corrugated surface defining layer "^otating the carrier and adhesive
applicator rolls in juxtaposition to one another to contact the lines of
adhesive with the ridges of the corrugated surface defining layer and there-
by deposit series of spaced, pressure deformable spots of adhesive along
the lengths of the ridges of said layer, and thereafter contacting the planar
surface of the other layer with the series of spots on the ridges of the ;
corrugated surface defining layer, pressing the two layers together so that
they splay the respective spots in*o the spaces therebetween and form sub-
stantially continuous lines of adhesive along the lengths of the ridges,
and bonding the two layers together at the lines of adhesive on the ridges,
including at points on the planar surface of the other layer coinciding with
the spaces between the spots.
In this way, the thickness of the "lines" of adhesive on the
ridges can be set at whatever dimension is necessary to account for the
` mechanical tolerances of the applicator equipment and the caliperdifferences
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between the two layers. This follows from the fact that when the two layers
are pressed together, the spaces between the spots accommodate the adhesive
and enable the layers to achieve an optimum condition in which they closely
approach one another, if in fact they do not contact one another. On the
other hand, the pressure applied to the layers need only be that which is
sufficient to achieve the splaying effect, and generally this is less than
that which would cause one layer to deform the surface of the other. In
practice, the optimum splaying effect is determined empirically and is that
which achieves the maximum bonding effect without deforming the surfaces
of the layers.
The spacing of the intervals between spots is a function of whether
a continuous or discontinuous line of adhesive is sought, as well as a func-
tion of the splay which can occur within the above described limits. Where
the spacing is siz~able, it is preferred to stagger the spots in relation
to one another from one ridge to the next. In this way the spots are always
out of alignment with one another perpendicularly of the ridges. On the
other hand, where the frequency of the spots is such that they splay together,
they may be aligned with one another from one ridge to the next.
In the initial bonding operation, the lines may be formed on and
about an adhesive applicator roll which is rotated in juxtaposition to the
corrugated surface defining layer.
The lines of adhesive may be formed by using a plain cylindrical -
adhesive applicator roll, depositing the adhesive on the roll, and doctoring
the roll with a grooved doctoring device to remove all but the adhesive in
the grooves.
Where a staggered effect is desired, the grooved doctoring device
may have a helical groove therein. Alternatively, ~he doctoring device may
have axially spaced grooves therein, and may be oscillated lengthwise of the
axis. Also, in such a case, the grooves may extend circumferentially of
the device and the device may also be rotated about the axis.
According to one technique for generating a pressure differential
across the corrugated surface defining layer on the carrier roll, the
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carrier roll may be apertured, and a vacuum may be generated inside of the
roll and applied to the apertures so as to retain the layer on the roll.
Where the corrugated surface defining layer has a corrugated body configura-
tion, preferably, the carrier roll has a corresponding outer peripheral
surface contour, and the apertures are disposed in the grooves in the outer
peripheral surface of the roll. Preferably, too, each groove has a series
of apertures therein which are spaced apart from one another lengthwise of
the groove.
Where the layers are laminated to one another in a corrugated board -
forming machine, the carrier roll for the corrugated layer web may be the
web-discharging roll in the pair of corrugating rolls which form the corru-
gated body configuration of the web.
BRIEF DESCRIPTION OF T~IE DRAWINGS
These features will be better understood by reference to the
accompanying drawings which illustrate one of the presently preferred embodi-
ments of the invention and certain modifications thereof.
In the drawings, Figure 1 is a schematic side elevational view of
a double-facer corrugated board forming machine;
Figure 2 is a part perspective view of the first lamination stage
of the machine wherein a first planar layer web is bonded to the corrugated
layer web to form an intermediate single faced composite;
Figure 3 is a part plan view of the adhesive application stage of
the first lamination stage;
Figure 4 is apart perspective view of the second lamination stage
wherein a second planar layer web is bonded to the intermediate composite to
form the final double-faced composite;
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1 FIGURE 5 is a part plan view oE the adhesive application
2 stage in this second lamination stage;
3 FIGURE 6 is a part fragmented perspective view of the
4 final product;
FIGURE 7 is a similarly fragmented plan view of the
6 product; `
7 FIGURE 8 is a schematic part cross-sectional represen-
8 tation of the contact stage of the second lamination s~age;
9 FIGURE 9 is another such representation of the pressure
10 application stage, illus-trating the splaying action which occurs
11 in the adhesive spots when the second planar layer web is pressed
12 into engagement with the intermediate composite;
13 FIGURE 10 .is a third such representation o~ the second
14 lamination stage after the splaying action has been completed and
15 thus illustrating the full effect of the splaying action; .
16 FIGURE 11 is a part perspective schematic representation .
17 of the contact stage of the firc;t lamination stage, after the
18 adhesive has been spotted onto l:he corrugated layer web, but .
19 before the first planar layer web has been bonded therewith;
. FIGURE 12 is a similar representation of the first
21 lamination stage after the first planar layer web has been bonded
22 with the corrugated layer web;
23 - FIGURE 13 is a representation corresponding to FIGURE
~4 lI r but illustrating the undesirable result that would be achieved
25 were a continuous line of adhesive formed on each ridge of the
26 corrugated layer web;
27 FIGURE 14 is another such representation illustrating .
28 the composite whi.ch would be produced under the circumstance in
29 which such a line of adhesive was formed on each ridge;
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Figure 15, found on the same sheet as Figures 6 to 10, is a part
cross-sectional schematic representation of the present product under com-
pression;
Figure 16, found on the same sheet as Figures 6 to 10, is a similar
representation of the product at the point of failure;
Figure 17, found on the same sheet as Figure 1, is a similar
representation of a prior art product under compression;
Figure 18, found on the same sheet as Figure 1, is the same
representation at the point of failure of the prior art product;
Figure 19, found on the same sheet as Figure 1, is a part fragment-
ed perspective view of the prior art product;
Figure 20, found on the same sheet as Figure 1, is a part cross-
sectional view of a finger-equipped corrugating roll of the type which has
been employed in prior art apparatus for making the prior art product;
Figure 21 is a relatively enlarged part perspective view of a
modified version of the adhesive application stage in the second lamination
stage of the inventive machine; and
Figure 22 is another such view of still another version of the
adhesive application stage in the second lamination stage of the machine.
DESCRIPTION OF I~IE PREFERRED EMBODIMENT
Referring first to Figures 1-3, it will be seen that the machine
employs three webs of paper 2, 4, and 6, one 2 of which is fed into the first
lamination stage 8 from a carrier roll 10' at the center of the machine, and
the other two 4 and 6 of which are fed into the first and second lamination
stages, 8 and 12, respectively, from carrier rolls 10" and 10"' disposed
more adjacent the ends of the machine. Each of the webs is fed by a power
driven feed and conditioning roll 14', 14", or 14" ', and may or may not be -~
subjected to steam preheating, as for example at 15, depending on the nature
of the adhesive employed.
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1 ¦The web 2 becomes the corrugated layer of the final composite 16,
2 ¦while the webs 4 and 6 become the first and second facing layers.
3 ¦ The web 2 is given its corrugated body configuration in
4 ¦the first lamination stage, as a consequence of being passed
5 ¦through the nip 18 (FIGURE 2) between a pair of power driven
6 ¦corrugating rolls 20 and 22 which are juxtaposed ln parallel but
¦vertically staggered relationship to one another and mated together
B ¦in conventional fashion at the nip. The relatively upper, web-
9 ¦receiving roll 20 is driven in the counterclockwise direction,
10¦ whereas the relatively l~wer web-discharging roll 22 is driven in
11¦ the clockwise direction. Normally, at least the upper roll i5
12¦ steam heated. Also, the lower roll 22 is equipped with a vacuum
13¦ eans 24 Eor temporarily retaining the corrugated layer web 2 on
14¦ the exterior surface 26 (F~GURE 3) of the same, ater the web has
15¦ exited from the nip 18 with its corrugated bod~ configuration.
16¦ The vacuum means is also operati.ve to maintain the corrugated
17¦ layer web in close registry with the contour of the surface 26,
18¦ and maintains it in such condition while the web is spotted with
19¦ adhesive and then laminated with the first facing-layer web 4.
20¦ ~he adhesive is applied to the aorrugatad layer web 2 by a power
21¦ driven adhesive applicator roll 28 which is mounted in parailel
22¦ ju~taposition with the roll 22 and contacted with the corrugated
23 layer web 2 while the web is subject to the vacuum in the roll.
24 The lamination step is accomplished by a pressure roll 30 which
25 is in receipt of the facing layer web 4 and mounted in parallel
26 juxtaposition with the roll 22 so as to feed the facing layer web
27 in the direction of travel of the corrugated layer web, and to
28 bond the facing layer web to the corrugated layer~web as the
29 latter exits from its path of travel around the roll 22. Afterward,
30 the intermediate two-layer composite 32 is reversed in direction,
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1 and is fed out of the first lamination stage 8 into the second
2 stage 12 where the second facing layer web 6 is bonded to the
3 composite 32 in a somewhat simllar manner, but on the opposite
4 side of the web 2, as shall be explained hereinaEter.
Turning now to FIGURES 2 and 3 in particular, it will
6 be seen that each of the corrugating rolls 20 and 22 has a hollow
7 cylindrical body construction and is spider mounted on a fixed
8 spindle 34 or 36 for lightness. Alternatelyr each roll may be
9 hub mounted. In all events, each is also axially elongated, and
10 is equipped with fluting which runs in the axial direction so
11 that the exterior surface of the roll has alternate, straight,
12 parallel, axially extending, substantially sinusoidally contoured
13 ridges 38 and grooves 40 about the circumference thereof. Moreover,
14 the spindle 36 of the lower roll 22 is hollow and ported, and the
15 bottoms of the grooves 40 in the surface 26 of the roll have
16 pertures 42 therein which are spaced apart from one another
17 engthwise of the roll 22, but at relatively staggered locations
18 from one groove 40 to the next circumferentially of the roll.
19 he apertures open into the interior of the roll 22 and because
f the ports 44 in the spindle 36, are subject to a vacuum which -
21 s generated in the spindle by a vacuum producing means 46 inter-
22 onnected with the spindle at one end thereof. The effect of the
2-~ acuum is limited, however, by the fact that the spindle 36 is
24 lso equipped with an arcuate shoe 48 which is secured to the
pindle 36 so as to assume a position in which it is relativèly
26 otatably engaged with the interior surface of the roll 22 through-
27 ut the clockwise arc defined between the nip 50 formed by the
28 ressure roll 30 and the lower corrugating roll ~2, and the nip
29 8 formed by the upper and lower corrugating rolls 20 and 22.
he shoe 48 effectively closes the apertures 42 over this arc,
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although as a practical matter the effect is only to save on the vacuum
generating capacity of the vacuum producing m~ans 46, since the shoe could
otherwise be discarded.
The adhesive applicator roll 28 also has a hollow cylindrical,
spindle or hub mounted body construction and is coextensive with the lower
corrugating roll 22 in the axial direction thereo~. However, the exterior
surface of the adhesive applicator roll is grooved, and the groove 54 extends
helically about the roll from one end thereof to the other, leaving a
helical land 52 on the surface of the roll. The roll is driven in the
counterclockwise direction and in operation, the land 52 relatively rotatably
engages the exposed ridges 2' of the corrugated layer web 2 while the groove
54 moves opposite the ridges 2' and because of its helical path, moves from
ridge to ridge at a slant dictated by the angle of the groove. Thus, the
groove 54 interfaces with the ridges 2' at intervals which are spaced apart
from one another lengthwise of the roll 22 but staggered in relation to one
another from one ridge 2' to the next lengthwise of the web 2.
Bands of the bonding adhesive are formed in the groove 54 for
contact with the ridges of the web. The bands are formed by applying the
adhesive to the surface of the applicator roll 28 and then doctoring the
surface with a doctor blade 56 which is interposed between the adhesive -
applicator mechanism 58 and the lower corrugating roll 22 in the direction
of travel of the applicator roll 28. The applicator mechanism 58 includes
an adhesive carrier pipe 60. The pipe is arranged in parallel to the appli~
i cator roll 28 on the opposite side thereof from the lower corrugating roll,
and is equipped with a series of longitudinally spaced and adjustably
orificed nozzles ~2 which
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1 ¦convert it into a manifold for flooding the adhesive onto the
2 ¦surface of the roll at a point just ahead o~ the doctor blade 56
3 ¦The blade is angled to the roll 2a in the direction of travel,
4 ¦and is relatively rotatably engaged with the land 52 of the roll
5 Ito doctor the land in the manner indicated, there being a tray 64
6 ¦(FIGURE l) below the roll to catch and recirculate the removed
7 ¦adhesive. In addition, a smaller diameter pipe 66 extends coaxi~
~D ~ ~30~8~ ally of and within the manifold 60 to carry a hot -bY~i, such as
9 ¦oil, which effectively maintains the temperature of the adhesive
10 ¦at the required degree o-f flowability.
11¦ The pressure roll 30 is also lightly constructed, and
12¦ is coextensive with the lower corrugating roll 22 but characterized
13 with a plain, smooth, cylindrical surface 68 on the exterior
1~¦ thereof. The roll 30 is driven in the counterclockwise direction,
151 and as seen in FIGURE l, the first facin~ layer web 4 is passed
16¦ about the same after being first: passed through a pair of
17¦ cooperating tensioning rolls 70. The roll 30 lightly engages the
18¦ eb 4 with the adhesively spotted ridges 2' of the corrugated
l9¦ la~er web 2, and effectively bonds one web to the other, as shali
~1 e more fully explained hereinafter with reference to FIGURES 6-
21¦ 14. Moreover, because of the fact that throughout its path of
22¦ travel between the nip 18 and the nip 50, the corrugated layer
231 eb 2 is retained in close registry with the contour of the lower
241 orrugating roll, the web~ 2 and 4 are bonded to one another only
251 in the desired inter~acial relationship, and only in the desired
26 ody configuration for the corrugated layer web 2, as has been
27 xplained hereinbe~ore.
28 Referring now to FIGURES l, 4 and 5, it will be seen
29 that following the first lamination stage 8, a system 72 of belt
3Q conveyors effectively reverses the orientation of the composite
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1 32, so that the composite assumes a condition in which the first
2 facing layer web 4 is disposed above the corrugated layer web 2. .
3 The same condition continues as the composite 32 enters the
4 second lamina~ion stage 12, and in this stage,-adhesive is spotted
5 onto the ridges 2'' on the underside of the corrugated layer web, .
6 that is, the side opposite from the first facing layer web 4. -
7 The means for applying the adhesive include a plain, smooth,
8 cylindrically surfaced, spindle mounted applicator roll 74. The
9 roll 74 is mounted crosswise of the composite 32 in cooperation .
10 with a power driven doctor device 76 which is relatively rotatably
11 engaged with the surface 80 of the roll so as to form a pattern of
12 raised, helically extending bands 78 of the adhesive on the roll
13 or application to the ridges 2'' of the web 2. As in the
14 first lamination stage, the adhesive is discharged onto the roll
15 74 from a heated manifold 60 ! the nozzles 62 o which are
16 tangentially angled to the roll :in the direction of travel thereof
17 and disposed at a point ahead of the doctor device 76. The
18 adhesive flows over the surface 80 of the roll and forms a coating
19 thereon, but the-coating is immediately doctored into the helical
20 pattern of the bands 78 by the doctor device 76. Consequently,
21 when the surface 80 o the roll interfaces with the ridges 2" of
22 the web 2, the adhesive is laid down on the ridges as localized .
23 spots 84 (FIGURES 8 and 11), and the spots are disposed at intervals .
24 spaced apart from one another lengthwise of the ridges 2" but
25 staggered in relation to one another from one ridge to the next
2G lengthwise of the composite 32.
27 The device 76 may take the form of a rotatably driven
28 rod 110 which has a helical groove therein, as in FIGURES 4 and
29 5; or the device 76 may take the form of a rod 112 which has
30 axially spaced grooves therein, and which is oscillated lengthwise
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1 of its axis, as well ~s perhaps rotated about its axis. FIGURE
2 21 illustrates an arrangement wherein the device 76 takes the
3 form of a cylindrically formed but circumEerentially grooved rod
4 112' ~hich is rotated about its longitudinal axis as well as
5 oscillated lengthwise of the axis; whereas FIGURE 22 illustrates
6 an arrangement wherein the device 76 takes the form of a flat but
7 edge notched rod 112" which is simply oscill~ted lengthwise of
8 its edge.
9 In each case, the doctor device 76-is mounted on the
10 distal end of a blade 114 which is flexibly cantilevered in the
11 direction of the roll 74 and operative to yieldably engage the
12 device with the surface 80 of the roll. Referring to FIGURES 21
13 and 22 in particular, it Will be seen that the manifold 6~ has an
14 edge-reinforced bed plate 116 welded or otherwise secured to the
15 top thereof, and the blade 114 is clamped between this bed plate
16 and an overlying backup plate 118 so as to be flexibly cantilevered
17 from the plates in the direction of the roll 74. In addition, the
18 holes 120 for the clamping bolts 122 are slotted so that the
19 lade can be advanced and retracted with respect to the roll, and
20 adjustment screws 124 are provided in the built-up edge 116' of
21 the bed plate to use in shifting the blade in relation to the
22 roll. Also, the manifold 60 is adjustable rotatably so that the
23 blade can be inclined to the roll 74 at an appropriate angle to
24 aintain the doctor device 76 under a slight bias as it bear~ on
25 thP surfacè 80 o~ the roll. Cap screws 126 are also provided on
26 the top of the backup plate 118 to aid in adjusting the tension
27 in the blade, and altogether the arrangement is such that the
28 achine operator can place the doctor device 76 under sufficient
29 ias to assure that it will remain on the surface 80 of the roll
otwithstanding that the surface may have a slight ellipticity or
31 ~other irre4ul ity about the~c~rcumference thereof.
".
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1 Where a rotatable rod is employed as the doctor device,
as in FIGURES 4, 5 and 21, the rod may be carried in a pair of
3 elongated arms 128 which are pivotally interconnected with the
4 laterally oriented edges of the blade a~sembly 114, 116, and 118.
5 Each arm 128 is secured to the blade assembly by a cap screw 130
6 which also provides a pivot for the arm; and in addition, each
7 arm has a vertically oriented slot 132 in the proximal end thereof
8 whereby a laterally outstanding pin 134 on the blade assembly can
9 be engaged in the slot to act as a stop for the pivotal movement
10 of the arm. Moreover, the ends of the rod 110 or 112' are shaped
11 as axles, the axles 136 are rotatably engaged in the distal ends
12 of the arms, and one axled end of the rod is equipped with a spur`
13 gear 138 which is engaged in turn with another such gear 140 that
14 is power driven to turn the rod.
In FIGURE 21, the gear 140 i.5 elongated to allow for
16 axial reciprocation of the gear 138 relative thereto, even while
1 17 the gears are engaged and turning. The reciprocatory effect is
18 generated by a lever-mounted yoke 142 which is pivotally inter-
19 connected with a power driven oscillating link 144. The yoke
20 straddles the gear 138 and responds to the oscillatory motion of
21 the link 144 by causing the same motion on the part of the gear
22 138, and thus the rod 112' as well. The motion of the rod in
23 turn produces an oscillatory effect in the bands 78 of the adhesive.
~4 Meanwhile, the rod rides over the surface 80 of the roll 74, and
25 under the bias of the blade 114, closely follows the contour of the
26 roll. -
27 In FIGURE 22 a notched edged blade 114' is substituted
28~¦ for ~he bladcs PIGURE~ 4, 5 and 21, and the edge 112" o- the
. ~ ' : .
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1 b:lade is applled directly to the surface 80 of the roll 74.
2 Moreover, the manifold 60' is flexibly coupled with the various .
3 liquid feeds to it, and is osclllated along its lengthwise axis to
4 impart a corresponding oscillation to the blade 114'. As seen,
5 the manifold has an axled end I46 and an oscillating yoke 148 is
6 clevised to the end to impart the oscillation to the manifold.
7 The second lamination stage 12 also resembles the first
8 inasmuch as the adhesively spotted web 2 is subsequently inter~aced
9 with the second facing layer web 6 and the latter web is light:Ly
10 pressure bonded to the c.omposite 32 to produce the final three
11 layer product 16. In the second stage, however, the weight of
12 the two layer composite 32 can be employed as a hold-down force
13 for the spotting and bonding steps, although as indicate~ in
14 FIGU~ES.l and 4, a series of idler rolls 86 is normally disposed
15 above the composite to maintain it in a planar condition as it~
16 passes over the adhesive applicator roll 74 and the pressure
17 applicator roll 88.
18 ~fter the two lamination stages, the final composite 16
19 is sent onto a cutter tnot shown), and/or to other stages 90
hich have no part in the invention and therefore are not speci-
21 ically illustrated. As is conventional, moreover, the conveyox
22 ystem 72 between the two stages feeds the composite in a slackened
23 ondition to avoid the necessity for synchronizing the stages.
24 In both lamination stages, the applicator mechanism 58
lso includes screw-operated valves 92 for adjusting the adhesive
26 low through ~he orifices of the nozzles 62~
n FIGURES 6-20 illustrate the nature of the composite
28 xoduct 16 and some of the distinctions between it and prior art
29 roducts. Referring first to FIGURE 8, it will be seen that the
dhesive is laid down on the ridges 2'' of the corrugated layer
11 ' I
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1 ¦web 2 in localized spots 84 that are spaced apart from one another
2 ¦lengthwise of the ridges. Also, as seen in FIGURE 7, the spots
3 ¦are staggered in relation to one another from one rid~e to the
4 ¦next in the directions crosswise of the ridges and lengthwise of
51 the product~ See angle 93 and note the increment of advancement
61 o~ the spots from ridge to ridge due to the helical pattern in
71 which they are laid down. Depending on the spacing between the
~¦ spots, the helical pattern may or may not be critical. -In some
9¦ embodiments of the invention, the spots are laid down in mutually
10¦ al1gned condition from ridge to ridge due to the narrow spacing
11¦ between spots. However, in most instances, a staggered relation-
12¦ ship from ridge to ridge is preferred.
13¦ FIGU~ES 8-12 illustrate the mannex in which the spots
~41 84 are squashed and splayed into the spaces therebetween as each
15¦ o~ the facing layer webs 4 and l; is applied to the ridges 2' or
16 2" of the corrugated layer web 2. The spaces may in fact be
17 closed by the splaying action so that the spots contact one
18 another to form a continuous line o adhesive 94, or they may
19 remain open in part so that the line of adhesive is somewhat
20 discontinuous. This again is a var1able which can be readily
21 controlled, depending on the result which is sought.
22 FIGURES ll and 12 also illustrate the fact that each
23 facial layer web is pressed into virtual contact with the ridges
~4 2' or 2'' of the corrugated layer web. Were adhesive 94 blanketed
25 over each ridge o~ the corrugated layer web, preliminary to the
26 web being interfaced with a facial layer web, as in FIGURE 13,
27 then to meet mechanical tolerances and to account for caliper
28 ifferences in the web materials, the adhesive would have to be
29 laid down in a thick line, and as indicated in FIGURE 14, the
30 resulting line or seam 94' of adhesive would actually become an
l(~qZ8'~3 ~ ~
1¦ additional laminar element in the composite 32', and one having
21 its own distinct characteristics. On the other hand, as illustratec
31 in FIGURE 12, the present invention enables each facial layer web
41 to substantially contact the corrugated layer web at the ridges
51 thereof, so that only the webs constitute layers of the composite.
61 Also, as seen in FIGURE 20, the fingers 96 employed in
71 the prior art devices produced both a break 97 in the continuity
81 of each ridge 98 of the corrugated layer web 100, and a break in
9l the continuity of the line 102 of adhesive on the same. Worst of
10¦ all~ the resulting depressions 97 in the ridges, and the gaps in
11¦ the adhesive, were mutually aligned with one ano~her on crosswise
12¦ perpendiculars to the ridges. See FIGURE 19. As a consequence,
13¦ when the corrugated product 104 was subjected to compression, as
14¦ in FIGURE 17, the so-called finger lines 97 constituted lines of
15 weakness at which early failure tended to occur. See ~IGURE 18
16¦ and compare this with FIGURE lS wherein the present product 16 is
17¦ illustrated under compression, and as seen, is free o~ any such
18 weakness zones, so that it does not buckle or otherwise fail until
19¦ the compressive forces simply overcome the strength o~ it, where-
21¦¦upon lt normal y failc at many points ~106, as might be expected.
221 '. ` . - .
241 . .
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271 . ' ' '
281 . .
291
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