Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a bag folding
and pac~aging machine, and particularly to an apparatus
for use in connection with folding bags made from a
flimsy material such as plastic.
The use of bags made of plastic material has
found wide acceptance and a large commercial mar7~et has
been developed. The physical differences between flimsy
~- bags such as bags made from plastic and bags made from
paper or cellulosic products has required the development
of new machinery and equipment in order to produce
plastic bags economically.
Generally, plastic bags can be made of film
forming polymers such as polyethylene, polypropylene, and
poly~7inylchloride and the like and can be multilayered.
In comparison to the paper or celluloslc counterparts
the plastic bags have substantially poor structural
- rigidity, are thinner, and have much lower surface
friction characteristics.
; Generally, the manufacturing of plastic bags
starts with plastic film which is formed into separate
bags and these bags are then folded and packed into .
boxes which will eventually be puchased by the consumers.
In a typical production system, the plastic bag
is formed and then discharged into a receiving region
from which the final folding operation proceeds. Each
bag is discharged into the receiving region in a flat
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1 1 3~ ~3 1
state and slides into the region until a barrier generally
referred to as a fence prevents further sliding of the bag.
When the bag comes to rest, it must be in substantial align-
ment with the fence.
It has been found that the poor alignment of the
plastic bag in the receiving region can interfere with subse-
quent operations and thereby reduce production efficiency.
Poor alignment tends to occur for the plastic bag in a prior
art apparatus freguently because the leading edge of the bag
which is to be stopped by the fence has poor structural rigid-
ity so that the leading edge can some times be distorted.
Another cause of poor alignment is that the bags are delivered
to the receiving system such that the leading edge is not
square with the feed direction. In order to overcome such
alignment problem, it is generally advantageous to impart cor-
rugations to the bag prior to its discharge to the receiving
region which thereafter are at least partially retained so as
to stiffen the leading edge of the bag thereby allowing it to
square up when it strikes the fence.
Generally, this problem of poor alignment subsequent
to discharge can occur even in a bag with corrugated regions
if the dimension of the bag in the feed direction is relative-
ly large. It has been found that even a large plas~ic bag
which has been folded one time before being discharged with
corrugated regions can become misaligned because of the poor
retention of the corrugated regions during the movement of the
bag into the receiving region.
It is a goal of the present invention ~o overcome
this problem and thereby improve the production efficiency and
economy for bags made of flimsy material such as plastic.
It is to be understood that the invention is not in-
tended to be limited to bags and that the invention can also
be used in connection with sheets of flimsy material and the
,~
`-- like.
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113~831
One of the principal ob~ects of the invention is an
apparatus for use in connection with folding bags made from a
flimsy material, comprising feeding means operable for dis-
charging successive bags in a feed direction with each bag
having a plurality of corrugated regions having grooves in the
- feed direction and havins undulations in the transverse
direction, receiving means operable for receiving the bags
from the feeding means and operable for maintaining in each
of the bags at least some of the corrugated regions at least
until each of the bags stops its movement along the feed
direction, and a fence near the receiving means for stopping
- the movement for each of the bags along the feed direction.
Another object of the invention is the apparatus
for use in connection with folding bags wherein the feeding
means comprlsing a set of shafts and a plurality of spaced
tires mounted on the shafts in coo?eration with each other
to provide the plurality of corrugated regions in each bag
and to move each bag in the feed direction.
A further object of the invention is the apparatus
for use in connection with folding bags wherein the receiving
means comprises a pluralitv of upper rods and a plurality of
lower rods and the rods cooperate with each other in order
to maintain in each of the bags at least some of the corrugated
regions at least until each of the bags sto~s its movemen,
along the feed direction.
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113C~831
Further objects and advantages of the invention
will be set forth, in part, in the following specification
`~f and, in part, will be obvious therefrom without being
specifically referred to, the same being realized and
attained as pointed out in the claims hereof.
The invention accordingly comprises the features
r` of construction, combination of elements and arrangement
of parts which will be exemplified in a construction
hèreinafter set forth and the scope of the application
of which will be indicated in the claims.
For a fuller understanding of the nature and
objects of the invention, reference should be had to
the following detailed description, taken in conjunction
with the accompanying drawings, in which:
Fig. 1 shows the present invention in relationship
to a bag making machine and a folding and packaging
apparatus;
Fig. 2 is a plan view of the present invention
with portions removed;
Fig. 3 is a partial side elevational v~ew of
the present invention with portions removed.
Fig. 4 is a cross-sectional view of the
invention along sectional line 4-4 of Fig. 2;
; Fig. 5 is a cross-sectional view of the
invention along sectional line 5-5 of Fig. 2 with
portions removed and illustrates a plastic bag being
corrugated;
113~33i
Fig. 6 is the same cross-sectional view as
Fig. 4 with additional portions removed and illustrates
a plastic bag in the initial stages of being transferred
for subsequent folding and packaging; and
Fig. 7 is the same as Fig. 6 but shows the
- plastic bag in a subsequent position of being transferred.
In carrying the invention into effect, an
embodiment has been selected for illustration in the
accompanying drawings and for description in the
specification, reference being had to Figs. 1 to 7.
Fig. 1 shows a complete system for producing
folded and packaged bags from a roll of plastic film.
For the embodiment shown, plastic film 10 in the form
of a roll 11 is moved around roller 12 into a bag making
machine 13. The plastic film 10 on the roll is prefolded
longitudinally,
It is to be understood that the plastic film 10
could be supplied from an extruder and thereafter prefolded
prior to entering the bag making machine 13. The plastic
film 10 can also be supplied from other known ways such
as from a roll without the film having a fold and
prefolding the film prior to its entering the bag making
machine 13.
Typically, the bag making machine 13 can be a
Model 208 Polyethylene Bag Making Machine manufactured by
1~3~1331
G. T. Schjeldahl Company in cDmbination with a Model
Accu-Folder Folding Machine manufactured by FMC Corporation.
The machine 13 produces a bag 14. The bag 14 is
longitudinally folded with the crease being the leading
edge. The crease, however, is usually not well defined
due to the characteristics of the film. The bag 14 moves
through feeding means such as corrugating roller 15 into
a receiving means 1~. The bag 14 comes to rest in the
receiving means 16 in a generally flat condition and
thereafter is removed from below such as shown by bag 17
by nip rollers 18 in combination with belts 19 for
additional processing and packaging by apparatus 20.
From Figs. 2 and 3, it can be seen that bags
can be moved by conveying system 22 to corrugating rollers
15 into a plurality of upper rods 23 and a plurality of
lower rods 24. An adjusting system 21 allows the groups
of rods to be moved vertically to obtain a predetermined
spacing at a predetermined height. Each rod position
within its group is adjustable. Each of the corrugating
rollers 15 comprises a drive shaft 25 and tires 26.
f Generally each of the tires 26 is an annular
ring of an elastic material and each tire 26 frictionally
engages the shaft 25. The material can be a plastic such
as polyurethane or a rubber-like material or the like.
The tires 26 are grouped in clusters and serve to grip
and remove bags from the conveying system 22
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113~31
when the corrugating rollers 15 are driven. Each group o_
tires 26 forms a corrugated region in a bag passing between
the corrugating rollers 15.
As used herein, a corrugated region is a physical
variation as shown in Fig. 5 which shows four corrugated
regions.
The corrugated regions provide good structural
rigidity to the bag so that when the leading edge contacts
the barrier, the bag resists deformations which would tend
to misalign the bag. The corrugated regions improve the
rigidity of the leading edge as well as the rigidity of the
overall body of the bag so that the bag misalignment is
corrected when it strlkes the fence.
From Figs. 2 and 3, it is evident that the invention
is not directed to a system requiring bags to be stacked in
the receiving region.
The interaction between a bag 27 and the tires 26
can be seen by reference to Figs. 4 and 5. The relationship
between the rods 23 and 24 with respect to the tires 26 can
be seen by reference to Fig. 4.
Generally, the end portions of the upper rods 23
near the corrugating rollers 15 are positioned to extend to
approximatelv the lower extremities of the tires 26 on the
upper rod 25. Similarlv, the end portions of the lower rods
24 near the corrugating rollers 15 are positioned to be near
the upper extremities of the tires 26 on the lower rod 25.
113C~33~
Fig. 6 shows a plastic bag after it has come to
rest after sliding between the rods 23 and 24 tD a
barrier such as fence 28. The fence 28 is a linear
arrangement of fixed vertical cylinders as shown in
Figs. 2 and 3.
The bag 27 is moved towards pinch roller 18
by an air knife means 30. Generally, an air knife is
a linear arrangement o~ air nozzles which provide a
blast of air for moving a plastic bag towards pinch
rollers. A typical air knife is described in the U.S.
patent no. 3,918,698 to Coast.
For a bag removal system using an overhead air
knife and pinch rollers, it is preferable to define a
corrugation in the bag to correspond to the space between
the pinch rollers and generally to extend towards the
pinch rollers. As shown in Fig. 6, it is preferable to
have a rod 31 above the bag 27 and tending to deform the
bag 27 towards the rollers 18.
Fig. 7 shows the plastic bag 27 after it has been
engaged by nip rollers 18 and is being pulled downward
between belts 19.
I wish it to be understood that I do not desire
to be limited to the exact details of construction
shown and described, for obvious modifications will occur
to a person skilled in the art.
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-
Having thus described the invention, what I
claim as new and desire to be secured by Letters Patent,
is as fDllows:
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