Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS OF MAl~luFAcTuRlNG POROUS
POUCHES CONTAINING GRANULAR PRODUCT
AB.DUL SATTAR BAHRANI
TECHNICAL FIELD
This invention relates to a method and apparatus for
manufacturing a porous laminated sheet product having at least
one compartment formed therein containing an inner product, and,
more particularly, to a method and apparatus of manufacturing
laminated porous pouches containing granular product and
featuring fluid pressure granular product placement.
BACKGROUND ART
Over the years, many methods and apparatuses for
manufacturing various bags, pouches and sealed packages have
been devised. An example of a method and apparatus for
manufacturing tea bags in disclosed in U.S. Patent 4,262,473,
which issued to Arthur A. Brooke on April 21, 1981. In the
Brooke method, a porous web is formed into a flattened closed
tube as a continuous stream of tea product is introduced
therewithin. The flattened tube filled with tea product first
travels generally horizontally and means are provided to pinch the
tube closed at predetermined intervals therealong. The pinching
means are adapted to maintain the tube in its pinched condition as
the tube is then moved vertically, thereby causing the tea
product contained therein to migrate downwardly under gravity
creating a voided area immediately below each pinch line. The
porous tube is then heat sealed transversely along the voided
areas of the tube. Further means are provided to separate the
successive sections from the tube to form individual tea bags or
groups of such bags.
U.S. Patent 3,498,019, which issued to J. M. Rait on March
3, 1970, also discloses a method and apparatus for forming sealed
packages. The Rait sealed packages are formed from
thermoplastic material wherein predetermined amounts of product
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are dosed onto the upper surface of a lower thermoplastic sheet
in a predetermined pattern. Thereafter, a second thermoplastic
sheet is brought in parallel to the first sheet and the two sheets
are heat sealed together by a heated compartmentalized rotating
5 cylinder. The movement of the upper and lower plastlc sheets is
synchronized with the rotational movement of the heated
compartmentalized cylinder such that the compartments on the
surface of the cylinder are positioned over the deposited product
as the sheets are rnoved below the rotating cylinder.
A method of packaging predetermined volumes of incoherent
product is disclosed in U.S. 3,813,848, which issued on June 4,
1974 to Andrea Romagnoli. The Romagnoli process utilizes a
rotary dispensing drum having batching recesses formed therein
to deposit predetermined doses of incoherent material onto the
upper surface of a moving web of packaging material . A second
band of wrapping material is thereafter bonded to the upper
surface of the first sheet of material to cover the heaps of
product deposited thereon. A similar volumetric batching device
is shown in U.S. Patent 4,437,294, which aiso issued to Andrea
Romagnoli on March 20, 1984. U.S. Patent 4,404,787, which
issued to G. Hazelwood on September 20, 1983, similarly discloses
a machine for packaging tea which includes a rotary dispensing
drum which deposits tea in predetermined piles on a lower web
and, thereafter, seals an upper web of packaging material onto
the upper surface of the lower web about the perimeter of each
pile. Individual tea bags are then separated from one another by
a cutter.
A method of manufacturing an infusion package with an
expandable bottom is taught -in U.S. Patent 2,571,138, which
issued to H . O . I rmscher on October 16, 1951. The I rmscher
method includes folding a porous sheet of web material in half,
then clamping the two parallel open sides by a pair of pincher
jaws thereby creating a bag-like structure having an open top.
A measured quantity of infusion product is then placed in the bag
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through its open top, and, thereafter, the top opening and the
transversely extending side portions are heat sealed to form a
closed pouch. A tag and string handle are then added to each
bag by a separate operation.
A soap powder package heat sealed about its periphery and
including additional heat seals delineating predetermined
compartments in such package is shown in U.S. Patent 4,433,783,
which issued to R. H . Dickinson on February 28, 1984. The
Dickinson package includes a pair of cooperating front and rear
heat sealable panels arranged on opposite sides of the soap
powder which is spread out as a layer therebetween. The panels
are heat sealed along their peripheral edges to form a storage
compartment for the soap, and, thereafter, a plurality of
additional heat seals are made to divide the storage compartment
into a series of subcompartments to minimize shifting of the
powder stored therewithin during handling. Dickinson teaches
that the additional heat seals within the storage compartment can
be made despite the presence of soap powder interposed between
the heat sealable panels.
A method and apparatus for making sanitary napkins or the
like is disclosed in U.S. Patent 2,073,329, which issued to C. P.
Winter on March 9, 1937. In the Winter process a rotatable wheel
having screened inlets connected to a source of suction collects
cotton fibers in a predetermined pattern and deposits those cotton
fibers on a gauze web moving along the bottom edge of the first
rotating wheel. The gauze web is then moved to a second
rotating wheel, and as the gauze web is rotated about the
periphery of the second rotating wheel, additional loose absorbent
material is forced in a predetermined pattern onto the previously
deposited loose cotton patches to selectively build up a wad or
pad on the web. The gauze web is thereafter forwarded with its
built up pads for further processing.
Despite the great amount of prior work done with regard to
improving the process of making laminated products having inner
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compartments containing quantities of inner product, as
evidenced by some of the above-described patents, there remain
problems in efficiently producing such laminated products with
high quality and at high speeds on automatic equipment. For
example, with equipment and methods currently available in the
industry, accurate high speed dosing of predetermined amounts
of granular material is messy, unreliable and relatively slow.
DISCLOSURE OF THE INVENTION
It is an object of this invention to obviate the above-
described problems.
It is another object of the present invention to providea more efficient apparatus and method for making compartment-
alized, laminated sheet products having upper and lower porous
web members connected about their periphery and containing a
predetermined pattern and quantity of product therewithin.
It is also an object of the present invention to provide
an apparatus and process to more efficiently maintain the
periphery of compartments within such upper and lower porous
web members clear of contained product to facilitate the
connection of such porous web members while making porous
pouches containing a predetermined pattern and quantity of
product therewithin.
It is another object of the present invention to provide
a more efficient apparatus and method for making porous
pouches having upper and lower web members connected about
their periphery and containing a predetermined dose of
granular product.
In one embodiment of the present invention, there is
provided an apparatus for making a porous laminated sheet
product having upper and lower web members connected about
their periphery and having at least one compartment formed
therein, and containing a predetermined quantity of inner
product within the compartment, at least one of the web
members being porous. The apparatus comprises: (a) a
compartment-forming surface having at least one inner product
loading area formed therein which further comprises a cavity
surrounded by peripheral land areas; (b) means to place a
lower porous web in contact with said compartment-forming
surface such that said lower porous web overlies said cavity
and said peripheral land areas; (c) a passageway, means to
selectively place said inner product loading area cavity in
fluid communication with a source of vacuum such that suction
can be selectively applied to said cavity; and (d) said
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peripheral land areas having one or more apertures formed
therethrough, a source of pressurized fluid, means to
selectively place said one or more apertures in fluid
communication with said source of pressurized fluid whereby
outward fluid flow emanates from at least a portion of said
peripheral land areas such that the vacuum acting through the
lower porous web holds the inner product within the portions
of the lower porous web which overlie the cavity and the
pressurized fluid acting through the lower porous web keeps
the inner product from being deposited on the portions of the
lower porous web which overlie the peripheral land areas.
A further embodiment of the invention is a process for
making a porous laminated sheet product having at least one
compartment formed therein and containing a predetermined
quantity of inner product within the compartment. The process
comprises: (a) placing a first porous web of material in
contact with a compartment-forming surface, said compartment-
forming surface having at least one cavity adapted to be
selectively placed in fluid communication with a vacuum
source, said cavity being surrounded by peripheral land areas
having at least one aperture formed therein adapted to be
selectively placed in fluid communication with a source of
pressurized fluid whereby outward fluid flow can emanate from
at least a portion of said peripheral land areas; (b)
selectively placing said at least one cavity in fluid
communication with said vacuum source and selectively placing
said at least one aperture in fluid communication with said
source of pressurized fluid; (c) depositing a quantity of
inner product on the upper surface of said first porous web
such that the vacuum source acting through said first porous
web tends to hold said inner product against the upper surface
of said first porous web in said cavity, while said
pressurized fluid acting through said first porous web tends
to keep said inner product from being deposited on the upper
surface of first porous web in said peripheral land areas; and
(d) supplying a second web of material and laminating the
lower surface of said second web to the upper surface of said
first porous web along said peripheral land areas, thereby
forming one or more porous compartments sealed about their
periphery.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims
particularly pointing out and distinctly claiming the present
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5 a
invention, it is believed that the same will be better
understood from the following description taken in conjunction
with the accompanying drawings:
Figure 1 is a schematic diagram illustrating an
embodiment of the method for forming a porous laminated sheet
product of the subject invention;
Figure 2 is a pictorial perspective enlarged cross-
sectional view of a portion of the compartment-forming surface
of the subject invention including a portion of a porous
laminated sheet product formed thereon:
Figure 3 is a perspective view of a preferred embodiment
of an apparatus for making a porous laminated sheet product of
the subject invention.
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Figure 4 shows a partial cross-sectional view of the
compartment-forming surface of the subject invention having a
first porous web of material in contact with the upper surface
thereof;
Figure 5 illustrates the compartment-forming surface of
Figure 4 after quantities of inner product have been deposited on
the upper surface of the first porous web;
Figure 6 illustrates the compartment-forming surface of
Figure 5 after high spots in the deposited product have been
eliminated;
Figure 7 is a partially broken away top plan view of a
porous laminated sheet product formed using the method an-d
apparatus of the subject invention;
- - - Figure 8 is a cross-sectional~ - view --of- ~~a~ portion of the
laminated sheet product of Figure 7 taken along lines 8-8 thereof;
and
Figure 9 illustrates an alternate embodiment of a porous
laminated sheet product formed using the method and apparatus of
the subject invention.
DETAILED DESCRIPTION
Referring now to the drawings in detail wherein like
numerals indicate the same elements throughout the views
Figures 1 and 2 illustrate the details of a method and apparatus
for making a porous laminated sheet product having upper and
lower web members connected about-their periphery and having at
least one compartment formed therein. The compart nent formed
within the porous laminated sheet product contains a
predetermined cjuantity of inner product therewithin. In particu-
lar Figure 1 schematically illustrates a continuous process 10 for
forming laminated sheet product 18 wherein upper web member 16
and lower web member 15 are continuously fed to a compartment-
forming apparatus 50. Compartment-forming apparatus 50 further
comprises a mold-depositing core 51 and an outer rotatable
mold-depositing drum 52 having an inner portion 54 and an outer
compartment-forming surface 53.
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Outer compartment-forming surface 53 is shown as having at
least one inner product loading area 55 formed therein comprising
a cavity 56 surrounded by peripheral land areas 57. A plurality
of cavities 56 are illustrated as being substantially square in
5 configuration, however, the shape of cavities 56 and peripheral
land areas 57 could be formed in any desired shape to correspond
to the shape of the compartment or compartments required in the
laminated sheet product. A passageway 58 is adapted to place
the inner product loading area 55 in fluid communication with a
10 source of vacuum (not shown) such that suction can be selec-
tively applied to cavity 56, as will be discussed in greater detail
below. Passageway 58 is shown as a single bore, however, any
number of passageways can be utilized to place the inner product
- - loading area 55 in fluid communication~-with a-source of vacuum.
15 The peripheral land areas 57 are illustrated as having one or
more apertures 59 formed therethrough adapted to be selectively
placed in fluid communication with a source of pressurized fluid,
whereby outward fluid flow can emanate from at least a portion of
the peripheral land areas 57, as will be described in greater
20 detail below. Such pressurized fluid can comprise any
appropriate fluid, however, preferably comprises a gas such as
air.
Passageways 58 are illustrated as exter~ding into the interior
of mold-depositing core 51 wherein there may be various ducts
25 and channels which lead to a source of vacuum. The manner in
which the inner product loading area 55 is placed in fluid
communication with a source of vacuum is not critical, and the
structure shown and describeci is meant to simply illustrate a
preferred embodiment of such structure. Likewise, apertures 59
30 may be connected to a series of duct-like channels 61 designed to
connect apertures 59 to one or more sources of pressurized fluid.
Such internal channels 61 may also be routed through the
mold-depositing core 51. It should be understood that channels
61, as well as the vacuum ducts 63, can be designed to
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selectively place certain apertures 59 or passageway 58
individually in fluid communication with a source of pressurized
fluid or vacuum, respectively, as the outer rotatable mold-
depositing drum 52 is rotated about mold-depos~ting core 51
5 during the product forming procedures.
Compartment-forming surface 53 is preferably designed for
rotatable movement about the stationary mold depositing drum 51.
Compartment-forming surface 53 may be formed from any
reasonably rigid material such that it retains its structural shape
10 after machining, casting or molding . Examples of materials from
which a compartment-forming surface 53 may be formed are poly-
urethane, aluminum, hard rubber, various steel alloys and the
like. A large range of dimensions for cavities 56 may also be
utilized. For example, if substantially rectangular compartments
15 are desired (as shown), the individual inner product loading
areas 55 might range in dimensions from about 0.5 to about 3
inches (between about 13 mm and about 76 mm) or more square.
The dimensions of the peripheral land areas 57 may also be varied
according to the particular application, depending upon overall
20 compartment size and desired land area requirements. For exam-
ple, for the substantially rectangular inner product loading areas
55 having outer side dimensions of between about 13 mm and
about 76 mm, peripheral land areas 57 having a width of approxi-
mately ,125 inches (about 3.17 mm) might be utilized. Depth of
25 cavities 56 may also vary according to specific compartment
dimension requirements. Overall diameter of mold-depositing core
51 and outer compartment-forming surface 53 can also be varicd
widely in accordance with desired production speeds, individual
compartment sizes, overall laminated product dimensions, and the
30 like.
As mentioned, many different arrangements for internal
ducting of the vacuum and pressurized fluid may be used, includ-
ing internal plenum chambers or similar ducting arrangements
known in the industry. As will be described in greater detail
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below, whatever ducting system is utilized must have the capabil-
ities of selectively placing the inner product loading area 55 in
fluid communication with a source of vacuum such that suction can
be selectively applied to the cavity desired. L~kewise, the aper-
tures 59 of the peripheral land areas 57 must be adapted to be
selectively placed in fluid communication with a source of pres-
surized fluid such that outward fluid flow (e.g., air) can emanate
when desired from at least a portion of the peripheral land areas.
It should also be understood that while the apparatus and process
of the subject invention is described most preferably as a rotat-
able structure, the compartment-forming surface 53 could also be
a substantially flat surface designed for use in a reciprocating-
type apparatus or in a manual forming process. In such case,
compartment-forming surface 53 could be formed as a stationary
structure or as a portable structure, as desired. Additionally,
although it is preferred that the compartment- forming surface 53
be formed as a substantially tubular-shaped structure having a
plurality of inner product loading areas 55 located adjacent one
another and being completely surrounded and separated from
adjacent loading areas by the peripheral land areas 57, it is also
contemplated that an individual inner product loading area 55
surrounded by land areas 57 could equally facilitate the
manufacture of porous laminated sheet products having a single
compartment formed therein containing a predetermined quantity
of inner product. For economy and efficiency, however, a
compartment-forming surface comprising a plurality of inner
product loading areas 55 formed about a substantially tubular
shaped structure to create a rotatable continuous pattern
compartment-forming surface is preferred.
Turning now to the process illustrated in Figure 1 in greater
detail, a first web of porous material 15 is supplied from an
unwind roll 21, and tension on web 15 is maintained by a simple
dancer-type tension control system common to the industry. An
example of such a tension control system is illustrated as
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including tension rolls 22 through 24 and continuous web 15
weaves through these rolls as it is moved toward
compartment-forming apparatus 50. Web 15 can be a variety of
foramenous materials cbmmonly available in the industry such as
5 paper perforated thermoplastic material cloth and the like;
however the web must be relatively porous and it is preferred
that it have multidirectional strength and stretch In order to allow
the product to be formed on the apparatus without web failure.
Various paper webs which can be utillzed in the subject process
are described in the commonly assigned U.S. Patent
4,638,907, issued January 27, 1987, by William T. Bedenk
and Kendall L. Hardin and entitled Laminated Laundry
Product.
First porous web 15 is brought into contact with the upper
' 5 surface of compartment-forming surface 53. E~ecause compart-
ment-forming surface 53 is to be formed with one or more cavities
56 it is preferred that first porous web 15 be deformed in a
manner corresponding to the contours of compartment-forming
surface 53. Such deformation may taken place prior to simul-
20 taneous with or after first porous web 15 is brought into contactwith compartment-forming surface 53. Figure 1 illustrates an
embodiment wherein first porous web 15 is embossed by a male
embossing roll 75 after it is brought into contact with the com-
partment-forming surface 53. Embossing roll 75 may be knobbed
25 in a manner corresponding to the contours of compartment-forming
surface 53 or alternatively may simply be a soft rubber roll
which forces web 15 into the relieved areas of surface 53. The
exact manner of deforming web 15 is not critical and in some
circumstances migl1t be accomplished simply by applying a suf-
30 ficient vacuum force to the web 15 after it is brought into contactwith surface 53 to pull portions of web 15 into the relieved areas
thereof. Weight of deposited product in relieved areas may also
help to complete this embossing process. Turning roll 25 is
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illustrated only as an example of a means for bringing the first
porous web 15 into contact with compartment-forming surface 53.
To facilitate the web deforming procedures, it is also con-
templated that web gathering equipment (not shown) mlght advan-
5 tageously be incorporated to provide "slack" in the web in themachine and/or cross-machine direction. Such web gathering
equipment is commonly available in the industry and may be more
desirable when porous web 15 is not easily deformable otherwise,
or if web 15 if relatively easily punctured or perforated.
10It is contemplated that compartment-forming surface 53 will
be continuously rotated in a clockwise direction so that, as
illustrated in Figure 1, web 15 will be rotated beneath the feeder
device 84 where a predetermined quantity of inner product P can
-- be deposited on the upper surface thereof.~ rthis regard, it is
15 highly preferable that cavity 56 of inner product loading area 55
be placed in fluid communication with a vacuum source prior to
the deposition of inner product P. Product P can be any product
which is desired to be placed within a laminate sheet product and
which can free-fall or be entrained in air or fluidized so that it
behaves much like a liquid during deposition procedures (such
free-falling product shall be hereinafter referred to as "fluidized"
product for simplicity). It is important that product P can
behave ITke a liquid or fluid so that the combination vacuum and
flutd pressure deposition control system of the subject invention
can be most advantageously utilized. In this regard, product P
is preferably a fibrous material or a comminuted or granular
material. Another advantage of the present invention is that
granular material having a "sticky" or adhesive nature can
conveniently be handled by this unique vacuum and fluid
30 pressure deposition control system.
As illustrated in Figure 1, product P is supplied to compart-
ment-forming apparatus 50 from hopper 80. In particular, from
hopper 80 it is contemplated that product P may be uniformly
transported to a feeder device 84 via a conveying or metering
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12
device 82. Conveying device 82 can be any of a number of
commonly available conveying devices such as a vibrating con-
veyor conveyor belt or the like. Conveying device 82 may help
prepare product P (e.g. by separating indivldual flbers or gran-
5 ulesl so that it can behave substantially like fluid within feederdevice 84 prior to its deposition on the upper surface of porous
- web 15. The fluidized product P falls through feeder device 84
and is deposited on the upper surface of the web 15. During
such deposition procedure cavities 56 must be in fluid
10 communication w~th a vacuum source and apertures 59 must be
placed in fluid communication with a source of pressurized fluid.
The porous web 15 acts as a filter to collect the fluidized product
as the vacuum pulls it into cavity 56. Product P builds up as a
substantially uniform layer within a cavi~y 56e as best shown in
15 Figure 5.
It is contemplated that passageways 58 should be of suffi-
cient size to enable a relatively larger volume of air to pass
inwardly therethrough than the total volume of air passing out-
wardly through apertures 59. This relationship is important
20 because when it is insured that the net force through the system
is in an inward direction the net force on the web 15 will be
inwardly thereby holding the web against compartment-forming
surface 53 during the product deposition and lamination
procedures as described herein. Additionally this inward net
25 air flow helps to insure that the product deposition procedure is
performed in a slight vacuum thereby controlling product P dust
and minimizing potential waste of product P which might resu!t
therefrom if product P dust were to escape from the system into
the ambient air. The fluidized or airborne product P is rained
30 or sprinkled onto the upper surface of web 15 at a predetermined
rate via feeder device 82 and entry chute 84 and the vacuum
source tends to attract the airborne product P to cavities 56 while
the pressurized fluid (e.g. air) emanating from apertures 59
tends to repel the airborn product from peripheral land areas 57.
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13
The exact pressures of the vacuum and pressurized fluid sources
are not critical and may vary according to the physical
characteristics of product P being deposited, amount of product
to be deposited, rotational speed of compartment-forming
5 surfacing 53, and other related factors. It is important to
remember that the vacuum and gravity must create sufficient
holding power through web 15 to attract and hold the deposited
product P against its upper surface, and to overcome the
resultant centrifugal forces created by the rotational movement of
10 the forming surface 53 and the deposited product P. Fluid
pressure emanating from land areas 57 must be sufficient to
overcome gravity forces and adhesive characteristics of product P
which is deposited over such land areas from entry chute 84.
For example, it has been fDund that for square cavities which are
15 nominally 1.5 inches labout 38 mm) on a side, and for a product
P having a range of granular size between about 100 and about
1000 microns, passageways 58 should be approximately 3/8 inches
in diameter, and fluid and vacuum pressures can preferably range
between about 12 and about 20 inches ( between about 305 and
20 about 508 mm) of water.
For the continuous forming process illustrated in Figure 1, it
is contemplated that the stream of product P can be continuously
and uniformly deposited via a feeder device 84. It is
contemplated that product P might be dosed through feeder device
25 84 in either a gravimetric or volumetric manner (e.g, feedback
monitoring systems might be used to control product deposition by
weight). Additionally, if more than one product P is to be
supplied, such individua! products may be independently
controlled and synchronized with either the rotational speed of
30 forming surface 53 or the desired weight of finished product 18.
Because of the fluid pressure emanating from peripheral land
areas 57, product P may be deposited uniformly over
compartment-forming surface 53 in applications where a single
product P is being deposited. This fact facilitates product
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14
deposition because no fancy patterns or method of precisely
depositing the product in particular areas is needed. Fluid
pressure emanating from apertures 59 continuously and
automatically maintains peripheral land areas 57 substantlally free
S of deposited product. It has been found, however, that If the
cross-machine direction width of product P streams being
deposited within product loading areas 55 is limited to a width
less than the cross-machine width of cavities 56 into which
product P is being deposited, fluid pressure emanating from
10 apertures 59 located along the machine-direction land areas 57 can
be minimized or even eliminated. It is preferred, however, to
supply pressurized fluid in both the machine and cross-machine
directions to insure the relative deposit-free cleanliness of land
areas 57 without a need for precise-product ~eposition control.
15 While the width of land areas 57 may be varied according to the
particular forming surface details (as mentioned above), it has
been found that maintenance of substantially deposit-free lands
during deposition of product is best assured by making lands 57
at least .125 inches (3.17 mm) in width. This minimum width
20 allows the outwardly flowing fluid pressure to create a "tunnel"
along the length of the land areas 57 and insures sufficient
outward flow of pressurized fluid through web 15 therealong to
maintain the lands substantially free of deposited product.
As mentioned, a wide variety of materials may be deposited
25 as inner product P utilizing the process of the subject invention.
For example, inner product P may comprise granulated tea or
coffee particles, granulated soap particles, cotton or paper
fibers, super absorbent materials, or any other product which
can behave substantially like a fluid, as described above.
30 Products having lesser densities may require additional vacuum
flow to ensure the prompt settling and compaction of such product
within cavities 56 during the product deposition procedure, and
to overcome centrifical forces resulting from the rotational
movement of the apparatus and deposited product P. This unique
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1s
combination of vacuum and fluid pressure deposition enables the
continuous manufacture of porous laminated sheet products having
one or more compartments containing a predetermined quantity of
inner product therewithin at speeds much faster than were
possible heretofore.
Figure 4 illustrates a cross-sectional view of a portion of
compartment-forming surface 53 after first porous web 15 has
been brought into contact therewith and deformed in a manner
corresponding to cavities 56 thereof. Figure 5 illustrates the
same portion of compartment-forming surface 53 as illustrated in
Figure 4, after product P has been deposited on the upper
surface of web 15. As illustrated the vacuum communicating with
cavities 56 via passageways 58 has attracted product P to within
cavities 56, whi!e pressurized fluid emanating from apertures 59
has tended to repel product P from being deposited on the upper
surfaces of web 15 over peripheral land areas 57. As is also
apparent, however, it has been found that the deposited product
P within cavities 56 extends upwardly slightly in the areas
adjacent peripheral land areas 57 forming peripheral high spots
90, While such peripheral high spots 90 generally do not
interfere with further manufacturing procedures, it is preferred
that they be reduced somewhat prior to lamination procedures,
especTally where the upper laminate is to be a flat and/or
non-stretchable sheet. As shown in Figure 1, after product P
has been deposited on the upper surface of web 15, the web and
its filled cavities are rotated beneath a doctoring mechanism 70 to
reduce the peripheral high spots 90 prior to lamination of the
second web to the upper surface of web 15.
Figure 6 illustrates the portion of compartment-forming
surface 53 as shown in Figure 5 after peripheral high spots 90
have been substantially eliminated by the doctoring mechanism.
Doctoring mechanism 70 can comprise any means which could
perform the necessary doctoring function; for example a blade,
brush or air knife. It has been found that a substantially soft
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16
brush structure which need not necessarily touch the upper
surface of web 15 over the peripheral land 57 performs
adequately. This doctoring step should be completed while the
vacuum is communicating with cavities 56 and pressurized fluid is
emanating from apertures 59 to facilitate confining product P to
cavities 56 as desired.
Whether or not the doctoring step is undertaken,
compartment-forming surface 53 continues to rotate in a clockwise
direction and a second web of material is supplied and laminated
to the upper surface of porous web 15 along the peripheral land
areas 57 thereby forming one or more porous compartments sealed
about their periphery. As illustrated, upper web 16 is supplied
from an unwind roll 31 and moves through a standard dancer-type
tension control system (rolls 32 through 34). Figure 1 illustrates
an adhesive printing system comprising an adhesive print roll 41,
a corresponding pressure roll 42, an adhesive supply reservoir
44, and adhesive 43. It is contemplated that such adhesive 43
may be pattern printed (such as by a gravure type adhesive
printing system) or generally applied to the surface of web 16
which is to be laminated to the upper surface of lower porous web
15. The method of laminating upper web 16 to lower web 15 is
not critical and may be accomplished by any of the various
lamTnating methods known in the industry. For example, such
lamination can be achieved by adhesives (as illustrated), heat seal
bonding, pressure sensitive bonding, high pressure bonding such
as knurling, and the like. In this regard, the pressurized fluid
emanating from the peripheral land areas 57 might be heated or
include steam or the like to facilitate a heat seal or knurling
bonding process.
Upper web 16 is then brought into a path of travel tangent
to the outer periphery of forming surface 53 and laminated to the
upper surface of lower web 15 along peripheral land areas 57,
thereby forming one or more compartments or pouches within the
laminated sheet product. Figure 1 shows lamination roll 36 as an
.
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example of a means to accomplish such lamination. Lamination roll
36 might be a male embossing-type laminator, or simply a soft
pressure roll. It has been found that upper web 16 should be
brought into a path tangential to formlng surface 53 at some
5 distance from surface 53 to minimize entraneous air currents
which might be established if web 16 were turned around a
turning roll near surface 53. Figure 1 shows turning roll 35 as
being located somewhat remotely from forming surface 53 to insure
that any such extraneous air currents will not affect product
10 deposited on the upper surface of web 15 prior to lamination with
web 16. Once this lamination has been completed, the vacuum
and pressurized fluid can be eliminated from acting upon the
laminated sheet product. Thereafter the finished laminated sheet
product 18 is removed from the compartment-forming apparatus
(e.g. by turning roll 37) for further processing and/or
packaging, as desired.
Figure 7 illustrates a plan view of an embodiment of a
finished laminated sheet product 18 which has been partially
broken away to show the detail of upper web 16, product P held
within the discreet compartments of product 18, and lower porous
web 15. Figure 7 also illustrates laminated sheet product 18 as
including more than one product P lP1 and P2) discretely
compartmentalized therewithin.
Figure 8 illustrates a cross-sectional view of a portion of the
finished laminated sheet product 18 of Figure 7 which might be
manufactured from the process and on the apparatus of the
subject invention. Height H of product 18 substantially
corresponds to the depth of the forming cavity in the forming
surface, as described. Figure 9 illustrates a portion of an
embodiment of another laminated sheet product 218 illustrating an
alternate shape of the individual compartments therewithin. In
particular, Figure 9 illustrates a contemplated pouch product
which might be used to form individual tea bags and the like on a
high speed process and apparatus of the subject invention. As
1299994
18
illustrated, peripheral land areas fqrmed in a pouch forming
surface of the subject apparatus and method can be utilized to
provide not only substantially deposit-free peripheral areas for
connecting the upper and lower webs about the deposlted
5 product, but also to similarly provide predesignated areas free of
deposited product which can be used for other pouch features
such as simulating a tea leaf stem 258. Tea leaf stem 258 could
be conveniently created by pattern printing of appropriate
adhesive as part of the lamination procedure for sheet product
10 218 to form a relatively rigid handle or "stirrer" for tea bags.
Perforations 259 might also be provided in laminated sheet product
218 to facilitate the separation of individual tea leaf pouches.
Figure 3 illustrates a pictorial perspective view of a parti-
cularly preferred example of the process_and apparatus described
15 herein for manufacturing pouches having upper and lower web
members connected about their periphery and containing a prede-
termined dose of granular product. In particular, the apparatus
of Figure 3 includes the deposition of three separate products
(P1, P2 and P3, respectively) into three rows of pouches to be
20 formed in seriatim within a single laminated sheet product.
Corresponding to the process as described above, a porous lower
web 115 is brought into contact with the outer periphery of
pouch-forming surface 153. A male embossing drum 125 embosses
lower porous web 115 as it is brought into contact with pouch-
25 forming surface 153. As mentioned earlier with regard to em-
bossing roll 75, a male embossing roll is not critical, and use of
a soft rubber roll could equally be utilized, or lower web 115
could be formed in a manner corresponding to the contours of
pouch-forming surface 153 prior to being brought into contact
30 therewith. Pouch-forming surface 153 is formed in a manner
substantially identical to compartment-forming surface 53
illustrated in Figure 2 and described above. It is preferred that
the vacuum and pressurized fluid sources (shown as 163 and 164,
respectively) be brought into fluid communication with the cavities
~ ~Z99994
19
and apertures of pouch-forming surface 153 as lower web 115 is
brought into contact therewith to facilitate holding the web
against surface 153 as it is rotated.
As illustrated, hopper 180 includes two product dividers 185
5 which separate the respective products P1, P2 and P3 as they are
conveyed toward the feeder chute 184 for deposition on the upper
surface of lower web 115. Rotating fluidizer 186 is shown as an
example of a way in which the respective products might be made
"airborne" or fluidized as they are fed into feeder chute 184. It
10 is contemplated that dividers 185 might extend throughout hopper
180, fluidizer 186 and feeder chute 184 to maintain the separation
of the products throughout the deposition procedure. It is also
contemplated that fluidizer 186 might combine features of standard
volumetric andtor gravimetric feeders to precisely and accurately
15 control independently the deposited quantity of products P1, P2
and P3, respectively, during the deposition process. Feeder
chute 184 is shown as having a slight curve corresponding to the
outer surface of pouch-forming surface 153 in order to provide
the free-falling or fluidized products with a velocity component
20 similar to that of rotating pouch-forming surface 153. Overall
velocity of products to be deposited may be varied by precisely
designing the vertical height and shape of feeder chute 184.
While dividers 185 may be used to maintain separation of the
individual products prior to deposition on the upper surface of
25 lower web 115 in a predetermined pattern, if several of the
products are incompatible with one another, it might also be
deslrable to increase the width of the peripheral land areas of
pouch-forming surface 153 in the machine direction and/or add
additional apertures and/or increase the fluid pressure emanating
30 therefrom. Any of these variables may be adjusted to insure that
such incompatible products remain isolated from one another. The
lowermost edge of feeder chute 184 may be formed as a doctor
mechanism 170 to reduce peripheral high spots in the product
`"` i299994
deposited within the individual cavities of pouch-forming surface
153 as described above.
A second web 116 of pouch-form7ng material is supplied via
unwind roll 131 and pattern printed with an appropriate adhesive
5 143 as it passes between the gravure-type adhesive printing roll
141 and pressure roll 142. Second web 116 is then tangentially
brought into contact with the upper surface of first porous web
115 and laminated thereto along the peripheral land areas
thereby forming a laminated sheet product 118 comprising a
10 plurality of pouches containing products Pl P2 and P3. The
laminated sheet product 118 may thereafter be cut into individual
products 119 as desired.
It is contemplated that the number and size of individual ~ ~ ~ ~ ~~~~ --compartments~ withi-n a laminated sheet product made in accordance
15 herewith may be varied as desired to accommodate a number of
different products and/or different product volumes within a
single compartmentalized laminated sheet product. Additionally a
plurality of similar vacuum and pressurized fluid product
deposition systems as described could be combined in the
20 process to achieve multi-stage or successive product deposition
prior to lar;ination procedures.
Having shown and described the preferred embodiment of the
present invention further adaptions of the method and apparatus
described herein can be accomplished by appropriate modifications
25 by one of ordinary skill in the art without departing from the
scope of the present invention. Accordingly the scope of the
present invention should be considered in terms of the following
claims and is understood not to be limited to the details of
structure and operation shown and described in the specification
30 and drawings.
I claim:
