Note: Descriptions are shown in the official language in which they were submitted.
CA 02414109 2002-12-12
1
APPARATUS AND METHOD FOR AUTOMATICALLY BALING LOOSE COMPRESSIBLE
MATERIAL
FIELD OF THE INVENTION
The present invention is concerned generallywith an apparatus and method for
compressing and
packaging loose fibrous material. More particularly, it relates to the
automatic baling of
compressible products. The invention is an apparatus and method particularly
well suited for
automatically baling sphagnum peat moss, by compressing and packaging the
product at a final
volume of 60% to 40% of its original loose volume.
BACKGROUND OF THE INVENTION
1o While various baler designs have been disclosed in recent years, no one can
address all the
problems that still exist when baling various compressible products,
particularly organic fibrous
products such as sphagnum peat moss.
Methods and machines that will allow vertical compression of loose fibrous
material into flexible
bags are well known and described in U.S. patent nos. 4,055,203 and 4,121,399.
These employ
a compression tube as well as a rigid container that holds a flexible bag.
These systems are
noisy due to the repetitive opening and closing of the rigid containers and
produce lots of dust.
Compressing product into the bag also leads to a certain proportion of damaged
bags.
Other methods and apparatus use a horizontal tube and manage to eliminate the
secondary rigid
container as described previously by entirely compressing the product into the
compression tube,
2 o thereby limiting noise and production of dust. However, these were
designed for products such
as cellulose that stay put after compression, but horizontal ejection of
products such as peat
moss bales is not acceptable since it causes the compressed product adjoining
the open end of
the bag to crumble and fall out of the bag. The bale thus loses its shape and
the collapsing face
contaminates the sealing area. Exemples of these methods that produce bags
either with ready-
2 5 made bags or by making them along the horizontal axis are given in U.S.
patents nos. 4,108,063
and 5,226,269.
CA 02414109 2002-12-12
2
The vertical form, fill and seal principle used on this invention relate
somehow to packaging
equipment that have been commonly used for many years but these existing
systems deal with
free filowing products and the machines do not have the capacity to produce
compressed bales
such as presented here. One application described in U.S. patent no. 4,391,081
presents a
method that slightly compresses the top of a bag but does not apply to baling
needs.
The baling apparatus of the present invention is distinct from and overcomes
several drawbacks
of the prior art devices, as will be discussed in detail below.
StlMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus for compressing
and baling in a
1 o continuous manner a compressible loose material. The apparatus comprises a
frame and an
upright compression tube mounted to the frame. The compression tube has an
open top end for
receiving the compressible loose material and an open bottom end. Feeding
means are provided
for feeding a certain amount of compressible loose material into the open top
of the compressible
tube. The apparatus further comprises a supporting surface to support the
loose material in the
compression tube. The supporting surface is movable vertically between a high
position where it
extends at the level of the bottom end of the compression tube and a low
position. pushing
means are provided for pushing the loose material in the compression tube
downwardly against
the supporting surface while the supporting surface is in the high position,
thereby obtaining a
compressed material. The pushing means is also for pushing the compressed
material out from
2 o the bottom end of the compression tube while the support is moved to its
low position.
The apparatus further comprises supply means mounted to the frame for
supplying in continuous
a flat thermoplastic plastic film and forming/sealing means for forming and
sealing the flat plastic
film into a continuous tube around the compression tube.
Further, sealing means are also provided adjacent to the bottom end of the
compression tube for
2 5 sealing a section of the tube of plastic film extending beyond the bottom
end of the compression
tube, and thereby closing a top end of a formed bale of compressed material
and a bottom end of
a following bale of compressed material to be formed;
The apparatus further comprises cutting means for cutting the sealed section,
and thus
separating the formed bale from the following bale to be formed.
CA 02414109 2002-12-12
3
Another object of the present invention is to provide a method of compressing
and baling in a
continuous manner a compressible loose material, the method comprising the
steps of
- providing an upright compression tube having an open top end and an open
bottom end;
-supplying in continuous a thermoplastic plastic film and forming and sealing
said plastic film into
a continuous tube around the compression tube;
-drawing the tube of plastic film sleeving the compression tube downwards
until a section of the
tube of plastic film extends beyond the bottom end of the compression tube;
-sealing the section of the plastic tube for obtaining a bottorr~ end of a
bale of compressed
material to be formed and cutting said section in two edges;
-feeding a certain amount of compressible loose material into the open top of
the compressible
tube;
-supporting the loose material in the compression tube by means of a
supporting surface
movable vertically between a high position where it extends at the level of
the bottom end of the
compression tube and a !ow position;
-pushing the loose material in the compression tube downwardly against the
supporting surface
to obtain a compressed material;
-pushing the compressed material out from the bottom end of the compression
tube while moving
the support surface to its low position, thereby causing the tube of plastic
film to be drawned
downwards until a further section of the tube extends beyond the bottom end of
the compression
tube ;
-sealing the further section of the tube of plastic film, and thereby closing
a top end of a formed
bale of compressed material and a bottom end of a following bale of compressed
material to be
formed; and
-cutting the sealed section, and thus separating the formed bale from the
following to be formed
2 5 bale.
As can be appreciated, the fibrous material is compressed in a vertical Tube
to form a bale, then
ejected, thus drawing a continuous supply of flat film that allovvs a bag to
being formed around
the tube. A variable position platform moves vertically under the tube to
control compression of
3 0 the material, the ejection of the bale by the compression ram and the
position of the bale for
sealing and cutting the bag off the continuous film supply.
The invention thus proposes both an apparatus and a method for automatically
baling and
bagging loose compressible fibrous material. !n operation, a thErmoplastic
film sheet is fed from a
CA 02414109 2002-12-12
4
supply roll through a film accumulating roller system and then to a tubular
forming section, which
wraps the thermoplastic film around the compression tube. The edges of the
thermoplastic film
sheet overlap on the front surface of the compression tube and these are then
sealed together to
create a continuous, thermoplastic film tube, which can be pulled along the
compression tube.
Initially, the lower end of the plastic tube is sealed and cut over the
compression tube outlet to
form the bottom of the bag. A support table then moves up against the bottom
of the bag, and the
boftom opening of the compression tube. A compression plate then pushes
fibrous material,
previously fed into the compression tube, onto the bottom of the bag. While
the compression
plate is compressing the fibrous material against the bag bottom and the
support table, air and
dust trapped within the fibrous product are being expelled through an air duct
located on the top
of the compression tube.
When maximum compression is reached, the supporttable gradually moves
downward, allowing
the compression plate to expel the compressed fibrous product bale out of the
compression tube
while drawing the continuously formed thermoplastic film tube around it and
keeping the bale
under a compression force. When the bale is completely expelled, the
compression plate
retracts, thus creating a vacuum, and the support table momenilarily moves
upward to aliow the
upper thermoplastic film surfaces to move onto each other. The portion of the
continuous tube
that exceeds the top of the new-formed bale is then simultaneously sealed and
cut, thus creating
the bottom of the next bag to be filled. The support table then moves down far
enough for the
2 o resulting packaged bale to be evacuated laterally to some conveying
device. At the same time,
the overlapping surfaces of the thermoplastic film are being welded and the
compression tube is
being filled with a metered quantity of compressible fibrous material in order
to start a new bale
production cycle.
This new approach offers numerous advantages over previous methods:
It reduces the cost of packaging material by:
Reducing the use of material, since no over length is required anymore to
compensate for
product expansion between the time that the bale is compressed and that it is
then brought to a
sealing station.
CA 02414109 2002-12-12
Making its own bags thus eliminating the costs of manufacturing by a third
party.
Eliminating the needs for corner seals required by bags in which the product
is
compressed.
Reducing the number of rejects by eliminating damaged bags.
5 It guarantees a better packaged product quality by eliminating the need for
the over compression
that destroys synthetic and natural fibers that is required by other systems
to compensate for
compressed product spring back uvhile the open bale is brought to a sealing
station.
It offers a smaller footprint than multi-station vertical units or all
horizontal units, thus freeing
valuable floor space.
1 o It allows for a much easier format change since it only needs one
compression tube change as
opposed to 4 compression tubes on carousel-type units currently used.
BRIEF DESCRIPTION OF THE DRA'NlINGS
These and other objects and advantages of the invention will become apparent
upon reading the
detailed description and upon referring to the drawings in which:
FIG. 1 is a perspective view of the compressible material baling apparatus;
FIG. 2 is a front elevational view of the apparatus of FIG. 1;
FIG. 3 is detail side view of the compression tube and the thermoplastic film
handling devices
along the side of FIG. 2;
FIG. 4 is a side elevational view of the apparatus of FIG. 1;
FIG. 5 is an enlarged perspective view of the bag handling devices;
FIG. 6 is a series of detail side elevational views of the bale forming and
bagging sequences.
CA 02414109 2002-12-12
6
While the invention will be described in conjunction with an example
embodiment, it will be
understood that it is not intended to limit the scope of the invention to such
embodiment. On the
contrary, it is intended to cover all alternatives, modifications and
equivalents as may be included
as defined by the appended claims.
DESCRIPTION OF A PREFERRED EMBODIMENT
As described previously, the present invention pertains to a compressible
material baling
machine that integrates the functions of bag making and compressed product
bale forming.
Fig. 1 shows the whole machine with its main modules. The basic frame (17)
supports the
replaceable compression tube, the thermoplastic flat film roll drive assembly
(3), the
thermoplastic film buffer and alignment module (16), the bale support table
and bale kicking
devices (8), the bag seating, cutting and handle making module (4), the
longitudinal film overlap
welding system (9), the compressible product metering and feeding system (1 ),
the compression
ram (7), pneumatic and hydraulic, controls (19) and finally, the bag ejection
conveyor (10)
Fig. 2 shows the airborne dust removal system duct connection (6) and the
tubular film forming
collar that allows to wrap the flat film roll stock around the compression
tube to form a continuous
film tube (5), the bale support table (8) assembly and the column that guides
its vertical
movement (22). Hydraulic oil reservoir (24) and pump (25) are also shown.
Fig. 3 shows the thermoplastic flat film roll (2) and main thermoplastic film
handling components:
guiding rolls (13), film roll support and driving rollers (11 }, film splicing
device (12), film buffer
(14), forming collar (5), longitudinal seam welder (9).
The compression plate (15) attached to the superior vertical hydraulic ram (7)
inside the
compression tube and the inferior vertical hydraulic ram (23) that moves the
bale support table is
also shown.
Fig. 4 shows a combination of Figures 1 and 3.
CA 02414109 2002-12-12
7
Fig. 5 shows the main electrical control components locker (20) and the
hydraulic oil reservoir
(24), the bag sealing, cutting and handle perforating assembly (4),
thermoplastic film guiding rolls
(13}, bale support table (8) and associated guiding column (22).
Fig. 6A shows the compression tube 811ed with loose product (25), the
compression plate (15}
and the bale support table in their, upper position.
Fig. 6B shows the compression plate (15) after being driven downward to
compress the loose
product (25) against the bag bottom (28) held tightly between the compression
tube (18) and the
bale support table (8) which is stiff in its upper position.
Fig. 6C shows the compressed product (29) being ejected out of the compression
tube (18} by
1 o the compression plate (15) white the bale support table (8) moves downward
at the same rate to
prevent the compressed product (29) from returning to its original loose state
(25).
Fig. 6D shows the compression plate (15} moving up back up to its starting
position and the bale
support table (8) moving up slightly to relieve the tension present in the
thermoplastic film and
allow opposing bag surfaces (30 and 31 ) to be drawn against each other by the
vacuum created
~ 5 in the upper portion of the bag by the moving compression plate (15). The
sealing and cutting
jaws of the the bag seating, cutting and handle making module (4) close to
seal the top of the
bale as well as the bottom of a new bag, and cut the film after a very short
delay to allow the
opposing bag surfaces (30 and 31 ) to move against each other and for a
gusseted fold to be
formed on each side, thus preventing the compressed product from expanding and
eliminating
2 o the need to over compress the material in order to compensate for the
expansion that would
occur between retraction of the compression plate and the sealing of the bag.
Fig. 6E shows the bottom of a new bag for the next compression cycle and the
top of the
compressed and sealed bale (26} being kicked away in order to make it fall
onto the outlet
conveyor, white the compression plate (15) continues to move back to its
starting position.
Fig. 6F shows the end of a cycle and the start of a new one as the compression
plate and the
bale support table (8) are back in their starting positions.
CA 02414109 2002-12-12
S
The preferred embodiments of the invention show: on Fig. 4: the flat film roll
(2) supported on
two rollers (11 }, one of them being driven by an electric motor {21 ) to
control film feed. This
principle allows the roll to lie low, close to the floor thus making it easy
to be loaded onto the
feeder from a lift truck and minimizing safety hazards related to dropping a
roll of several hundred
pounds from any height.
The thermoplastic flat film is fed through a splicing device (12), a film
buffer device {14} and a
series of rollers ( 13) (Fig. 3) to guarantee proper tension, feeding and
alignment of the film. The
flat film is formed into a continuous tube by running it over a forming collar
(5) that then allows the
film to wrap around the compression tube {18), with the two outer edges now
overlapping on the
center portion of the tube.
The overlapping edges offer surfaces that are welded together by the welding
device (9) that
preferably uses heated sealing bands but also can use a hot air jet to
minimize the height of the
device or an ultrasonic wheel welder of a combination of hot air and a
pressure roller.
The surfaces of the bottom end of the film tube are welded together in a
gusseted edges fashion,
at the bottom outlet end of the vertical compression tube to form the bottom
of a bag (Fig. 6E),
item (29).
As loose compressible product is fed into the top portion of the compression
tube by a feeding
and metering device (1 ), a bale support table (8} is moved against the bottom
of the compression
tube {18).
2o While hydraulic ram (7) exerts pressure on a compression plate (15) to
compress the loose
compressible product, hydraulic ram (23} exerts pressure on the bale support
table (8) to allow
compression of the bale within the compression chamber ((18).
When the desired compression rate is reached (Fig. 6C), the compressed product
(29) is ejected
out of the compression tube {18} by the compression plate (15) while the bale
support table (8)
moves downward at the same rate while keeping pressure on the compressed
product (29) to
prevent it from returning to its original loose state {25).
CA 02414109 2002-12-12
9
This movement also pulls flat film out of the film buffer (14) down along the
compression tube
(18) surface:
The new tubular film section is formed by welding the overlapping surfaces by
either:
- heating the film surfaces with hot air while film is being drawn over a hump
and past the welding
device (9) where pressure toilers above and below the hot air jet keep a
tension in the film that
forces the overlapping surfaces to fuse to each other;
or:
- applying a sealing bar consisting of heated metal strips with a pressure
that forces the
overlapping surfaces to fuse to each other;
or:
- drawing the overlapping surfaces under an ultrasound-generating roller that
welds the
overlapping surfaces together.
At this stage, the bale can be ejected further down to create a longer bag top
or bottom in which
a cutout for a handle can be made for bale carrying convenience.
Furthermore, a rectoseable bag feature (either mating extrusions or any other
type that is to be
applied on the horizontal axis, that is parallel to the bag opening) can be
built onto the bag prior
to sealing.
Once the compressed product (29) has been ejected far enough, fur the sealed
bate to be made,
the compression plate (15) moves up back up to its starting position and the
bate support table
2 0 (8) moves up slightly to relieve the tension present in the thermoplastic
film. This allows all four
opposing top bag surfaces to be drawn against each other while a gusseted fold
is formed on
each side of the bag. This is helped by the vacuum created in the upper
portion by the moving
compression plate (15).
CA 02414109 2002-12-12
Very quickly, the sealing and cutting jaws of the bag sealing, cutting and
handle making module
(4) close to seal the top of the bale as well as the bottom of a new bag, and
cut the film to
separate them.
The sealing and cutting head assembly is made of two horizontal heated metal
strips between
5 which there is a cutting means: the heated metal strips weld bag surfaces
together while the
cutting mans cuts through these surfaces with a knife. It is worth mentioning
that in another
embodiment, the cutting could advantageously be made by melting through the
thermoplastic
film.
This quick action prevents the compressed product from expanding and
eliminates the need to
10 over compress the material in order to compensate for the expansion that
would occur between
retraction of the compression plate and the sealing of the bag.
The bag support table (8) moves back down to its lowest position and the new
bale thus
produced is kicked away from the bag support table (8). The bag support table
then moves up
against the bottom of the newly formed bag to offer support in the next
compression phase.
A new batch of loose compressible product is being fed into the compression
chamber (18) as
soon as the compression plate, in its upward displacement, has passed the
product inlet.
The film roll (2} is indexed by actuation of the support rollers until the
film buffer {14) is
replenished.
Advantageously, an apparatus according to the invention is capable of
producing various fomlats
2 0 of bales by changing the replaceable compression tube, the bag former and
the compression
plate. Another advantage is that this apparatus is very secure to the user.
In the following description, similar features in the drawings have been given
similar reference
numerals and in order to weight down the figures, some elements are not
referred to in some
figures if they were already identified in a precedent figure.
