U.S. patent application number 12/418744 was filed with the patent office on 2009-07-30 for apparatus and method for automated forming of sleeves for sliced products.
This patent application is currently assigned to KRAFT FOODS GLOBAL BRANDS LLC. Invention is credited to Christian Laplace.
Application Number | 20090188215 12/418744 |
Document ID | / |
Family ID | 33490927 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090188215 |
Kind Code |
A1 |
Laplace; Christian |
July 30, 2009 |
Apparatus And Method For Automated Forming Of Sleeves For Sliced
Products
Abstract
A forming apparatus is provided for forming a film into a sleeve
around a filling tube. The forming apparatus has contact surface
geometry that is contacted by the film as it travels thereacross
configured to ensure smooth forming of the film into the sleeve.
Smooth forming of the film into the sleeve is achieved, in part, by
reducing longitudinal tensile forces in the film, by selecting the
contact surface geometry to minimize transverse variations in
tensile forces in the film, and by having contact edges of the
contact surfaces shaped to reduce unnecessary stresses in the
film.
Inventors: |
Laplace; Christian; (Dollard
des Ormeaux, CA) |
Correspondence
Address: |
FITCH EVEN TABIN & FLANNERY
120 SOUTH LASALLE STREET, SUITE 1600
CHICAGO
IL
60603-3406
US
|
Assignee: |
KRAFT FOODS GLOBAL BRANDS
LLC
Northfield
IL
|
Family ID: |
33490927 |
Appl. No.: |
12/418744 |
Filed: |
April 6, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11289991 |
Nov 30, 2005 |
7526906 |
|
|
12418744 |
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|
10628073 |
Jul 25, 2003 |
7003929 |
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11289991 |
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Current U.S.
Class: |
53/551 |
Current CPC
Class: |
B65B 25/068 20130101;
B65B 9/22 20130101; B65B 2210/02 20130101 |
Class at
Publication: |
53/551 |
International
Class: |
B65B 9/06 20060101
B65B009/06 |
Claims
1. A method of forming a film into a sleeve disposed around a
filling tube, the method comprising: feeding the film in a film
feed direction through a folding tunnel disposed around the filling
tube, the folding tunnel and filling tube each being operatively
connected to a common support member; folding a first longitudinal
side portion of the film at least partially around the filling
tunnel as the film moves in the film feed direction; folding a
second longitudinal side portion of the film, disposed opposite the
first longitudinal side portion of the film, at least partially
around the filling tunnel and overlapping at least a portion of the
first longitudinal side portion of the film as the film moves in
the film feed direction to form the sleeve; and the common support
member constraining the folding tunnel and filling tube against
significant displacement relative to one another.
2. A method of forming a film into a sleeve disposed around a
filling tube in accordance with claim 1, wherein the common support
member is pivotally connected by a pivot relative to a support
bracket effective to allow selective rotation of the forming tube
and filling tunnel relative to the support bracket.
3. A method of forming a film into a sleeve disposed around a
filling tube in accordance with claim 2, wherein a second folding
tunnel is disposed around a second filling tube is disposed
adjacent the folding tunnel and folding tube and operably attached
relative to the support bracket, the common support member being
pivotable about the pivot to provide access to the second folding
tunnel and second filling tube.
4. A method of forming a film into a sleeve disposed around a
filling tube in accordance with claim 1, further comprising the
step of stabilizing the forming tunnel relative to the filling tube
using the common support member effective to permit spacing between
outer surfaces of the filling tube and adjacent inner surfaces of
the forming tunnel to be minimized.
5. A method of forming a film into a sleeve disposed around a
filling tube, the method comprising: feeding the film in a film
feed direction through a folding tunnel disposed around the filling
tube, the folding tunnel having a first longitudinal portion and a
second longitudinal portion selectively separable relative to the
second longitudinal portion; folding a first longitudinal side
portion of the film at least partially around the filling tunnel as
the film moves in the film feed direction using a first folding
wing attached to the first longitudinal portion of the forming
tunnel; folding a second longitudinal side portion of the film,
disposed opposite the first longitudinal side portion of the film,
at least partially around the filling tunnel and overlapping at
least a portion of the first longitudinal side portion of the film
as the film moves in the film feed direction using a second folding
wing attached to the second longitudinal portion of the forming
tunnel to form the sleeve.
6. A method of forming a film into a sleeve disposed around a
filling tube in accordance with claim 5, wherein a first mounting
bracket is attached to the first longitudinal portion of the
forming tunnel and a second mounting bracket is attached to the
second longitudinal portion of the forming tunnel, the first and
second mounting brackets having a connection mechanism therebetween
permitting selective separation of the first and second mounting
brackets and the first and second longitudinal side portions
effective to permit access to the interior of the forming tunnel.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of prior application Ser.
No. 11/289,991, filed Nov. 30, 2005, which is a divisional of prior
application Ser. No. 10/628,073, filed Jul. 25, 2003, now U.S. Pat.
No. 7,003,929 B2, issued Feb. 28, 2006, which are hereby
incorporated herein by reference in their entirety.
FIELD
[0002] The subject matter disclosed herein relates to apparatus and
methods for forming film into a sleeve, and in particular apparatus
and methods for forming film into a sleeve in a continuous process
for the commercial packaging of a food product.
BACKGROUND
[0003] The processing of continuous food product into individually
wrapped serving portions is desirably accomplished using automated
equipment. The use of automated equipment can allow for increased
manufacturing efficiencies and productivity. In one such operation,
a continuous film is folded into a continuous sleeve. Food product,
such as cheese, can be continuously extruded into the sleeve. Once
the cheese has been extruded into the sleeve, the continuous
sleeve-encased cheese can be further treated and separated into
individually packaged slices by sealing and cutting of the
sleeve.
[0004] One such process for the processing of continuous food
product into individually wrapped serving portions involves the
folding of the film into the sleeve shape using a two-part forming
apparatus having a forming plate adjacent a folding tunnel. The
film is unwound from a roll of film and pulled over a forming plate
inclined at an angle of between 45 degrees and 75 degrees to a
folding tunnel. The forming plate is wide at its base, tapering
upward toward an entrance to the folding tunnel. Within the folding
tunnel is a cheese extruding tube through which cheese, or other
such food products, are extruded. The folding tunnel is configured
to form a sleeve around the extruding tube so that the food product
leaving a downstream mouth of the extruding tube is encased in a
film sleeve.
[0005] To this end, the folding tunnel is configured to form the
planar film into a sleeve for encasing the extruded cheese. The
folding tunnel includes a pair of overlapping angled members. The
overlapping angled members are staggered, such that one is
contacted by the film before the other. When the film contacts the
first of the angled members, one the longitudinal edges of the film
is folded over the cheese extruding tube. As the film continuous to
be advanced through the folding tunnel, the other of the
longitudinal edges of the film contacts the other of the pair of
overlapping angled members and is folded over the earlier folded
portion of the film. In this manner, the planar film is folded
about itself and around the cheese extruding tube. Once the cheese
exits the mouth of the cheese extruding tube, the cheese is encased
in the advancing sleeve and both are directed toward further
operations and finishing steps, including separation into
individually wrapped slices of cheese.
[0006] There are several disadvantages to the method of forming the
sleeve from the film using the forming plate and folding tunnel,
such as illustrated in FIG. 17. As the film is pulled over the
forming plate and through the folding tube, extreme variations in
force exist across the transverse width of the film between the
beginning of the forming plate and the exit of the folding tunnel.
These variations in force can cause the film to become destabilized
as the film tends to shift lengthwise away from the regions of
comparatively higher forces. When the film shifts toward the
regions of comparatively lower forces, the film may become skewered
on the forming plate and enter the folding tunnel at an angle, as
opposed to longitudinally aligned with the axis of the folding
tunnel. The film may also become skewered within the folding
tunnel. Skewering of the film can cause misfeeding thereof,
resulting in time consuming down-time for the machine and labor
intensive removal of the skewered film and reset-up of the system.
These disadvantages reduce the overall efficiency of the packaging
apparatus.
[0007] Another process for the processing of continuous food
product into individually wrapped serving portions involves the
folding of the film into the sleeve shape using a folding tunnel
having an integral folding ramp surface leading to the entrance of
the folding tunnel, such as illustrated in FIGS. 18 and 19 and
disclosed in U.S. Pat. No. 4,532,754. The film is unwound from a
roll of film and pulled over the folding ramp, which inclined at an
angle of about 133 degrees to the folding tunnel. The folding
tunnel is formed partially by folded portions of the ramp in
addition other portions adjacent thereto. Within the folding tunnel
is a cheese extruding tube through which cheese, or other such food
products, are extruded. The ramp and the folded portions thereof
are embossed with dimples in an attempt to reduce friction forces
between the contact surfaces of the film and the film.
[0008] The folding tunnel is configured to form a sleeve around the
extruding tube so that the food product leaving a downstream mouth
of the extruding tube is encased in a film sleeve. Like the
multi-part forming apparatus discussed hereinabove, the integrated
ramp and folding tunnel are configured to form the planar film into
a sleeve for encasing the extruded cheese. The folding tunnel
includes a pair of overlapping angled members. The overlapping
angled members are staggered, such that one is contacted by the
film before the other. When the film contacts the first of the
angled members, one the longitudinal edges of the film is folded
over the cheese extruding tube. As the film continuous to be
advanced through the folding tunnel, the other of the longitudinal
edges of the film contacts the other of the pair of overlapping
angled members and is folded over the earlier folded portion of the
film. The planar film is then folded about itself and around the
cheese extruding tube. As the cheese exits the mouth of the cheese
extruding tube, the cheese is encased in the advancing sleeve and
both are directed toward further operations and finishing
steps.
[0009] There are several disadvantages to the method of forming the
sleeve from the film using the integral ramp and tunnel. One
disadvantage is a large variation in forces in the film at the
beginning of the ramp and at the exit of the folding tube. The
variations in force can cause the film to stretch and skew. Another
disadvantage of the prior art integral former is its construction
of a thin material. The thin material edges which could cause
deformations in the film and increased friction therebetween.
SUMMARY
[0010] In order to address deficiencies with prior art forming
methods, a new method of forming a film into a sleeve disposed
around a filling tube is provided. The method includes the step of
feeding the film in a film feed direction over a continuous film
entrance surface to an entrance of a folding tunnel. At least a
portion of the entrance surface is inclined at an acute angle
relative to an extension of a longitudinal axis of the folding
tunnel. The method further includes the step of folding a first
longitudinal side portion of the film at least partially around the
filling tunnel or tube using a first folding wing of the folding
tunnel as the film is fed in the film feed direction. The method
also includes the step of folding a second longitudinal side
portion of the film, disposed opposite the first longitudinal side
portion of the film, at least partially around the filling tube and
overlapping at least a portion of the first longitudinal side
portion of the film using a second folding wing of the folding
tunnel as the film is fed in the film feed direction to form the
sleeve around the filling tube.
[0011] The method of forming a film into a sleeve disposed around a
filling tube may also include the step of selecting the acute angle
between the portion of the entrance surface and the extension of
the longitudinal axis of the folding tunnel to minimize the ratio
of tension forces in the film before the continuous film entrance
and after the folding tunnel. The acute angle between the portion
of the entrance surface and an extension of the folding tunnel,
i.e., the film path, may be selected to have the ratio of tension
forces in the film before the continuous film entrance and after
the folding tunnel be between about 1:1 and 2:1. The acute angle
between the portion of the entrance surface and the folding tunnel
may be between 40.degree. and 90.degree., and is preferably about
66.degree..
[0012] The steps of folding a first longitudinal side portion of
the film using a first folding wing of the folding tunnel and
folding a second longitudinal side portion of the film using a
second folding wing of the folding tunnel may each further comprise
the step of feeding the film around a folding wing contact edge of
each folding wing. Each folding wing contact edge may have a
thickness between 0.10 and 0.25 inches and may comprise an arcuate
portion in contact with the film. Each folding wing contact edge
may be positioned at an acute angle relative to an extension of a
longitudinal axis of the folding tunnel.
[0013] The method may further include the step of generally
maintaining constant forces along a transverse width of the film as
the film is formed into a sleeve. The step of generally maintaining
constant forces along a transverse width of the film as the film is
formed into a sleeve may include the step of feeding the film over
contact surfaces of the continuous film entrance surface, the first
and second folding wings, and the folding tunnel having geometry
selected to maintain a generally constant length of the film
between a beginning of the continuous film entrance and an end of
the folding tunnel in the film feed direction. By maintaining a
generally constant length of the film over the film contact
surfaces, the forces in the film will generally be equal across the
transverse width thereof. Equal forces across the transverse width
of the film can result in a reduction of propensity of the film to
shift laterally from areas of higher forces to areas of lower
forces when such force variations are minimized.
[0014] An apparatus is provided for forming a film into a sleeve
around a filling tube. The apparatus comprises a continuous film
entrance surface integrally connected to an entrance of a folding
tunnel. At least a portion of the entrance surface is inclined at
an acute angle relative to an extension of a longitudinal axis of
the folding tunnel. A first folding wing of the folding tunnel is
positioned for folding a first longitudinal side portion of the
film at least partially around the filling tunnel. A second folding
wing of the folding tunnel is positioned for folding a second
longitudinal side portion of the film, disposed opposite the first
longitudinal side portion of the film, at least partially around
the filling tunnel and overlapping at least a portion of the first
longitudinal side portion of the film in order to form a sleeve
around the filling tube.
[0015] The continuance film entrance surface may comprise a
generally planar central portion positioned between a pair of
curved side portions. Curved side portions of the continuous film
entrance surface may each be connected to one of the first and
second folding wings.
[0016] The acute angle between the portion of the entrance surface
and the extension of the longitudinal axis of the folding tunnel
may be selected to minimize the ratio of tension forces in the film
before the continuance film entrance and after the folding tunnel.
The acute angle between the portion of the entrance surface and an
extension of a longitudinal axis of the folding tunnel may be
selected to have the ratio of tension forces in the film before the
continuance film entrance surface and after the folding tunnel be
between 1:1 and 2:1. The acute angle between the portion of the
entrance surface and the extension of the longitudinal axis of the
folding tunnel may be between 40.degree. and 90.degree., and is
preferably about 66.degree..
[0017] Each of the first and second folding wings may include a
folding wing contact edge being arcuate and having a radius of
between 0.05 and 0.15 inches. Each folding wing contact edge may be
positioned at an acute angle relative to an extension of the
longitudinal axis of the folding tunnel.
[0018] Film contact surfaces of the continuous film entrance
surface, the first and second folding wings, and the folding tunnel
may have geometry selected to maintain a generally constant length
of the film between a beginning of the continuous film entrance and
an end of the folding tunnel in the film feed direction. By
maintaining a generally constant length of the film between the
beginning of the continuous film entrance and the end of the
folding tunnel, variations in tension forces across the transverse
width of the film can be minimized. This can result in a lack of
propensity for the film to shift from regions of higher force to
regions of lower force, which can reduce occurrences of the film
being misfed or skewered in the apparatus. A maximum transverse
width of the contact surfaces of the folding tunnel and first and
second folding wings in an unfolded configuration of the folding
tunnel may be approximately the same as a transverse width of the
film.
[0019] The apparatus may be formed of material approximately 0.125
inches thick. Such a thickness assists in insuring that appropriate
radiuses are present on contact surfaces with the film in order to
reduce stretching and unnecessary forces in the film. The material
may comprise stainless steel 17-4PH. In addition, the contact
surfaces of the apparatus are preferably free of plating in order
to reduce flaking thereof and the generation of minute sharp edges
on the contact surfaces which can harm the film.
[0020] In another aspect of the method, the method of forming a
film into a sleeve disposed around a filling tube includes the step
of feeding the film in a film feed direction through a folding
tunnel disposed around the filling tube. The folding tunnel and
filling tube are each operatively connected to a common support
member. The method further includes the step of folding a first
longitudinal side portion of the film at least partially around the
filling tube as the film moves in the film feed direction. The
method also includes the step of folding a second longitudinal side
portion of the film, disposed opposite the first longitudinal side
portion of the film, at least partially around the filling tunnel
and overlapping at least a portion of the first longitudinal side
portion of the film as the film moves in the film feed direction to
form the sleeve around the filling tube.
[0021] The method may also include having the common support member
pivotally connected by a pivot relative to a support bracket,
effective to allow selective rotation of the forming tube and
filling tunnel relative to the support bracket. A second folding
tunnel may be disposed around a second filling tube and disposed
adjacent the first folding tunnel and first folding tube and
operably attached relative to the support bracket. The common
support member may be pivotable about the pivot to provide access
to the second folding tunnel and second filling tube. The method
may further comprise the step of stabilizing the forming tunnel
relative to the filling tube using the common support member
effective to permit spacing between the outer surfaces of the
filling tube and adjacent inner surfaces of the forming tube to be
minimized.
[0022] In accordance with another aspect of the method, a method is
provided of forming a film into a sleeve disposed around a filing
tube including the step of feeding the film in a film feed
direction through a folding tunnel disposed around the filling
tube. The folding tunnel has a first longitudinal portion and a
second longitudinal portion selectively separable relative to the
second longitudinal portion. The method further includes folding a
first longitudinal side portion of the film at least partially
around the filling tunnel as a film moves in a film feed direction
using a first folding wing attached to the first longitudinal
portion of the folding tunnel. The method also includes the step of
folding a second longitudinal side portion of the film, disposed
opposite the first longitudinal side portion of the film, at least
partially around the filling tunnel and overlapping at least a
portion of a first longitudinal side portion of the film as the
film moves in a film feed direction using a second folding wing
attached to the second longitudinal portion of the forming tunnel
to form the sleeve.
[0023] The method may also include having a first mounting bracket
attached to the first longitudinal portion of the forming tunnel
and a second mounting bracket attached to the second longitudinal
portion of the forming tunnel. The first and second mounting
brackets may have a connection mechanism therebetween permitting
selective separation of the first and second mounting brackets in
the first and second longitudinal side portions effective to permit
access to the interior of the forming tunnel. By having such a
separable folding tunnel, the method permits the ready separation
of the folding tunnel halves in order to perform cleaning and other
operations in a simplified manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a top perspective view of an apparatus for forming
a film into a sleeve around a filling tube showing film being
directed therethrough and formed into a sleeve;
[0025] FIG. 2 is an end perspective view of the apparatus of FIG.
1;
[0026] FIG. 3 is another end perspective view of the apparatus of
FIG. 1;
[0027] FIG. 4 is a right side perspective view of the apparatus of
FIG. 1;
[0028] FIG. 5 is a left side perspective view of the apparatus of
FIG. 1;
[0029] FIG. 6 is a perspective view of a first portion of the
apparatus of FIG. 1 with a second portion of the apparatus
removed;
[0030] FIG. 7 is a perspective view of the second portion of the
apparatus of FIG. 1 with a first portion of the apparatus
removed;
[0031] FIG. 8 is an exploded perspective view of the apparatus of
FIG. 1;
[0032] FIG. 9 is a top perspective view of the apparatus of FIG. 1
and a similar second apparatus mounted to a mounting bracket
assembly;
[0033] FIG. 10 is a bottom perspective view of the apparatus and
the similar second apparatus mounted to the mounting bracket
assembly of FIG. 9;
[0034] FIG. 11 is a plan view of contact surfaces of the apparatus
diagrammatically shown in an unfolded orientation;
[0035] FIG. 12 is an end view representation of the apparatus
having the filling tube therein;
[0036] FIG. 13 is an end view representation of a prior art forming
apparatus having a filling tube therein;
[0037] FIG. 14 is a representative chart comparing the relation of
the tension force ratio between the tension force in the film at a
beginning of a continuous entrance surface and the tension force in
the film at an exit of a folding tunnel and an angle between the
continuous entrance surface and a longitudinal axis of the folding
tunnel;
[0038] FIG. 15 is a representative chart of the elasticity in the
sleeve comparing the tension force in the sleeve and the amount of
elongation of the sleeve;
[0039] FIG. 16 is a representative chart of the ratio of forces in
the film comparing the pulling force on the sleeve and the friction
forces acting thereon.
[0040] FIG. 17 is a perspective view of a prior art forming
apparatus having a separate entrance plate and forming station;
[0041] FIG. 18 is a perspective view of a prior art integral
forming apparatus;
[0042] FIG. 19 is a side view of the prior art integral forming
apparatus of FIG. 18;
[0043] FIG. 20A is a representative of tension forces in the film
due to the prior art forming apparatus of FIG. 17;
[0044] FIG. 20B is a representative of tension forces in the film
due to the prior art forming apparatus of FIGS. 18 and 19; and
[0045] FIG. 20C is a representative of tension forces in the film
due to the forming apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] There is provided a new forming apparatus 10 for forming a
film 400 into a sleeve 401 around a filling tube 90, as shown in
FIGS. 1-16. The forming apparatus 10 has contact surface geometry
that is contacted by the film 400 as it travels thereacross
configured to ensure smooth forming of the film 400 into the sleeve
401. Smooth forming of the film 400 into the sleeve 401 is
achieved, in part, by reducing longitudinal tensile forces in the
film 400. Reducing longitudinal tensile forces in the film 400
reduces stretching of the film 400, which can cause the film 400 to
misfeed and unnecessarily deformation of the film 400. Smooth
forming of the film 400 into the sleeve 401 is also achieved, in
part, by selecting the contact surface geometry to minimize
transverse variations in tensile forces in the film 401. Reducing
transverse variations in the tensile forces in the film 401
contributes to maintaining the film 400 properly aligned throughout
the processing of forming the film 400 into a sleeve 401, thereby
minimizing misfeeds, such as due to skewering, and associated
machine downtime. Smooth forming of the film 400 into the sleeve
401 is further achieved, in part, by having contact edges of the
contact surfaces shaped to reduce unnecessary stresses in the film
400.
[0047] The forming apparatus 10 is configured for integration with
a continuous, automated high speed operation for forming film 400
into a sleeve 401 for use in commercial food manufacturing and
packaging operations. To this end, the forming apparatus 10 is
configured to permit selective access to an interior thereof, such
as to permit periodic cleaning and maintenance that may be required
in a food packaging environment, as discussed further herein. The
forming apparatus 10 is also configured to permit use in
conjunction with one or more additional and similar forming
apparatus 100 by adapting a mounting frame 200 to permit movement
of one forming apparatus 10 to allow access to another of the
forming apparatus 100 disposed adjacent thereto, as will be
discussed in greater detail herein.
[0048] As illustrated in FIGS. 1-5, the forming apparatus 10
comprises a continuous entrance surface 50 for the film 400. The
continuous entrance surface 50 extends at an inclined angle to an
entrance 22 of a horizontally extending folding tunnel 20. The
angle between the continuous entrance surface 50 and an extension
of a longitudinal axis of the folding tunnel 20 is acute, as will
be discussed in more detail. That is, film 400 traveling from the
continuous entrance surface 50 to the folding tunnel 20 has a
change in its direction of travel of an acute angle. The folding
tunnel 20 has a pair of folding wings 30 and 40 positioned on an
upper surface 27 thereof in a staggered relationship and on
opposing sides of the folding tunnel 20. As will be discussed in
greater detail herein, surfaces of the continuous entrance surface
50, the folding tunnel 20, and the first and second folding wings
30 and 40 that contact the film 400 as it is directed thereacross
have geometries selected to minimize force variations across the
transverse width of the film 400 in order to reduce skewering of
the film 400 in the folding tunnel 20 and ensure smooth movement of
the film 400 through the forming apparatus 10.
[0049] Inserted within the folding tunnel is a filling tube, as
shown in FIGS. 9 and 10. The inner surfaces of the folding tunnel
20 and the outer surfaces of the filling tube 90 are sized to have
a space therebetween through which the film 400, and the film 400
as folded into a sleeve 401, can be directed. As the film 400 is
feed over the continuous entrance surface 50, it is directed
through the entrance 22 of the folding tunnel 20. A center portion
of the film 400 is directed beneath the filling tube 90 beginning
proximate the entrance 22 of the folding tunnel 20. As the film 400
continues to be advanced through the folding tunnel 20, a first
longitudinal edge portion 402 of the film 400 will contact a first
one of the folding wings 30 and be gradually folded at least
partially over the filling tube 90. As the film 400 is further fed
through the folding tunnel 20, a second longitudinal edge portion
of the film 404, opposite the first longitudinal edge portion 402
thereof, contacts a second one of the folding wings 40 and is
gradually folded at least partially over the filling tube 90 and
the first longitudinal edge portion 402 of the film 400. Turning to
more of the details of the forming apparatus 10, the forming
apparatus 10 comprises a pair of generally planar panels 52 and 54,
as illustrated in FIG. 8. These generally planar panels 52 and 54
are wedge-shaped, tapering from a wider base to a narrower width
adjacent entrance 22 of the folding tunnel 20. The wider bases of
the generally planar panels 52 and 54 are connected by a joining
piece 72. The joining piece 72 has a lip or groove 88 for receiving
the bottom ends of the planar panels 52 and 54 is a secure fashion.
One of the planar panels 52 is bolted or otherwise secured to the
joining piece 72. The other planar panel 54 removable from the
joining piece 72 for purposes as will be described further.
[0050] The planar panels 52 and 54 are positioned adjacent each
other. The periphery side edge of each of the planar panels 52 and
54 is connected to a curved side panel 58 or 60. The tapered or
angled periphery side edges of the planar panels each have a lip
formed therein 53 and 55. The lips 53 and 55 are each configured to
receive an edge portion 66 or 68 of a side curved panel 56 and 58.
By providing such lips 53 and 55, the side curved panels 56 and 58
can be secured along one of their lengths and substantially
prevented from skewing relative to the planar panels 52 and 54.
Portions of the curved side panels 56 and 58 and the planar panels
52 and 54 form the continuous entrance surface 50. The continuous
entrance surface 50 provides a continuous surface for supporting
the film 400 along its entire extent as it moves thereacross.
[0051] The folding tunnel 20 comprises a partially enclosed region
extending between an entrance 22 and exit 24 thereof. The folding
tunnel 20 is generally oval in cross-section, having an upper
surface and a lower surface connected at edges thereof by arcuate,
longitudinally-extending side regions 223 and 225. Upper regions of
the curved side panels 56 and 58 are attached to the upper surface
of the folding tunnel 20 on opposite sides thereof, as shown in
FIGS. 6 and 7. The upper surface of the folding tunnel 20 is
comprised of the first and second folding wings 30 and 40. To
secure the connection and proper positioning between the curved
side panels 56 and 58 and the first and second folding wings 30 and
40, keys 62 and 64 are provided on the curved side panels 56 and
58. Inserts 63 and 65 are formed on the upper surfaces of the first
and second folding wings 30 and 40 and sized to mate with the keys
62 and 64 of the curved side panels 56 and 58.
[0052] The forming apparatus 10 is readily separable into a first
half 12 and a second half 14, as shown in FIGS. 6 and 7,
respectively. Having the forming apparatus 10 separable into the
first and second halves 12 and 14 advantageously allows for access
to the interior of the folding tunnel 20 in order to permit
cleaning and other interior operations.
[0053] The first half 12 of the forming apparatus 10 includes one
of the planar panels 52, one of the side curved portions 56, and a
first half of the folding tunnel 122 having the first folding wing
30. The second half 14 of the forming apparatus 10 includes the
other of the planar panels 54, side curved portions 58 and the
second half 124 of the folding tunnel having the second folding
wing 40.
[0054] The components of the first half 12 of the forming apparatus
10 are mounted to an arm bracket 78 and an end bracket 76. The arm
bracket 78 is mounted to the underside of the planar panel 52 and
the underside, towards the entrance 22, of the first half 122 of
the folding tunnel 20. The end bracket 76 is mounted on the
underside of the first half 122 of the folding tunnel 20 and toward
the exit 24 thereof. The wider bottom portion of the planar panel
52 has the joining piece 72 attached thereto. The groove 88 of the
joining piece 72 is configured to receive the other planar panel 54
of the forming apparatus 10 and is sized to restrict relative
movement between the panels 52 and 54 when the first and second
halves 12 and 14 are joined.
[0055] Mounted on the underside of the components of the second
half 14 of the forming apparatus 10 is an elongated bracket 74. The
elongated bracket 74 has a plurality of holes 82 for alignment with
bolts 80 disposed in the end bracket 76 and arm 78 mounted to the
first half 12 of the forming apparatus 10. The bolts 80 or other
suitable means of connection allow for selective joining of the
first and second halves 12 and 14 of the forming apparatus 10. In
operation, the first and second halves 12 and 14 of the forming
apparatus 10 are tightly held together so that minimal gaps
therebetween exist. In order to separate the first and second
forming halves 12 and 14, such as for cleaning, the bolts 80 or
other securement mechanisms can be selectively released.
[0056] The geometry of the contact surfaces of the forming
apparatus 10 are selected to minimize stress on the film 400 to
result a smooth forming of the film 400 into the sleeve 401. In
addition to the geometry of the contact surfaces, smooth forming of
the film 400 into the sleeve 401 is assisted by a reduction of the
angle between the continuous entrance surface 50 and the
longitudinal axis of the folding tunnel 20 along the film feed
path. The angle therebetween is selected to reduce the overall
tension in the film 400, as will be discussed further herein. The
placement of the first and second folding wings 30 and 40 in the
film feed direction relative to the mouth or entrance 22 of the
folding tunnel 20 is chosen to reduce stresses in the film, such as
may be present in the closely-spaced folding surfaces and entrance
of the prior art integral former of FIGS. 18 and 19.
[0057] The forming apparatus 10 is configured to reduce the ratio
of the tension forces in the film 400 at the beginning of the
continuous entrance surface 50 and at the exit 24 of the folding
tunnel 20. One factor affecting the ratio of the forces include the
coefficient of friction between the film 400 and the contact
surfaces of the forming apparatus 10. Another factor is the angle
between the direction of the tension forces in the film 400 at the
beginning of the continuous entrance surface 50 and the direction
of the tension force at the exit 24 of the folding tunnel 20. When
the coefficient of friction between the film 400 and the contact
surfaces of the forming apparatus 10 is designated as .mu., the
tension forces at the beginning of the continuous entrance surface
50 is designated as P1, the tension forces at the exit 24 of the
folding tunnel 20 is designated as P2, and the angle between the
direction of the tension forces at the beginning of the continuous
entrance surface 50 and the direction of the tension forces at the
exit 24 of the folding tunnel 20 is designated as .theta., the
following relationship exists:
P.sub.1/P.sub.2=e.sup..theta..mu. Equation 1
[0058] The coefficient of friction between the film 400 and the
forming apparatus 10 was estimated to be about 0.33. The angle
between the direction of the tension forces at the beginning of the
entrance surface and the direction of the tension forces at the
exit of the prior art integral former of FIGS. 18 and 19 is about
133 degrees. Using this coefficient of friction, the ratio of
tension forces in the film at the beginning of the entrance surface
(P.sub.1) and at the exit (P.sub.2) for the prior art integrated
former was about 2.15. By comparison, the angle between the
direction of the tension forces at the beginning of the continuous
entrance surface 50 and the direction of the tension forces at the
exit 24 of the folding tunnel 20 is about 66 degrees. Thus, the
ratio of tension forces in the film 400 at the beginning of the
continuous entrance surface 50 (P.sub.1) and at the exit 24 of the
folding tunnel 20 (P.sub.2) for the forming apparatus 10 is about
1.46. The ratios for the prior art integral former and the forming
apparatus 10, along with the ratios for various contact angles, are
plotted in the chart of FIG. 14. FIGS. 20B and 20C illustrate the
anticipated reduction in magnitude of tension forces between the
prior art integral former and the forming apparatus 10.
[0059] The forming apparatus 10 is further configured to reduce
variations in tension forces across the transverse width of the
film 400 during forming into the sleeve 401. This can be
accomplished by configuring the geometry of film contact surfaces
to aid in smooth forming of the film 400 into the sleeve 401. The
contact surfaces for the film 400 include portions of the
continuous entrance surface 50, folding tunnel 20, and first and
second folding wings 30 and 40.
[0060] One method of configuring the geometry of the contact
surfaces is to have the tensile forces across a given width of the
film 400 be constant. This can reduce variations in such tensile
forces and thereby reduce the propensity of the film 400 to skewer,
such as by moving laterally from an area of higher tensile force to
an area of lower tensile force. FIGS. 20A and 20C illustrate the
anticipated reduction in tension force variations between the prior
art separate former and the forming apparatus 10. As can be seen in
FIG. 20A, the film in the prior art former can tend to shift toward
the center of the film due to higher forces along the lateral edge
portions thereof.
[0061] To assist in determining the geometry of the contact
surfaces, the film 400 can be modeled as comprising an infinite
number of longitudinally-extending springs. The equation for
calculating the force (F) in a spring, having a given spring
constant (k), that has been stretched a predetermined amount (l) is
as follows:
F=kl Equation 2
[0062] Using this equation, a goal in configuring the surface
geometry is to have the forces due to stretching of the film 400 be
generally constant across the width of the film. That is, the term
generally constant is used to mean that the tensile forces in the
film 400 should not vary so significantly during normal forming
operations so as to cause the film 400 to become unintentionally
skewered in the forming apparatus 10.
[0063] One method of having the forces for the many hypothetical
springs longitudinally aligned to model the film 400 be generally
constant is to have the length of the hypothetical springs each be
about the same. Given that the spring constant (k) would be about
the same for each of the hypothetical springs due to being actually
formed of the same film material, which may be a single or multiple
layer polymer, maintaining generally constant spring tension forces
across the width 410 of the film 400 can therefore be accomplished
by having the length of each of the hypothetical springs be about
the same. As shown in the chart of FIG. 15, there is a correlation
between the amount of stretching in the film 400, such as can be
measured per length of packaged slice product, and the force
exerted on the film 400. To apply this theory to the film 400, the
forming apparatus 10 is configured to have contact surfaces with a
geometry configured to generally maintain a constant length of the
film 100 as it is fed thereover.
[0064] More specifically, the contact surfaces of the forming
apparatus 10 are selected to have a maximum width approximately the
same as the width of the film 400 when the contact surfaces are in
a hypothetical unfolded orientation, as diagrammatically
illustrated in FIG. 11. The contact surfaces include portions of
the continuous entrance surface 50, which includes portions 412 and
414 of the planar entry panels 52 and 54. The portions 412 and 414
of the planar entry panels 52 and 54 are operable connected to the
curved side portions 56 and 58. The curved side portions 56 and 58
each have portions 422 and 424 comprising film contact surfaces.
Proximate the mouth or entrance 22 of the folding tunnel 20 is a
mouth contact surface 416 formed by the intersections of the
contact surface portions 412, 414, 422 and 424 of the planar
portions 52 and 54, contact surface portions of the curved side
portions 56 and 58, and a bottom surface 26 of the folding tunnel
20. Intersecting regions 423 and 425 of the curved side portions
have arcuate configurations selected to minimize film stretching as
the film enters the mouth 22 of the folding tunnel 20.
[0065] The film contact surfaces also include portions of the first
and second folding wings 30 and 40. The bottom 26 of the folding
tunnel 20 is connected at lateral sides thereof 434 and 444 to
arcuate lateral regions 223 and 225 of the folding tunnel 20. The
arcuate lateral regions 223 and 225 are connected to the first and
second folding wings 30 and 40. The portions of the first and
second folding wings 30 and 40 include angled contact edges 430 and
440 (shown in the folded configuration). As partially shown in FIG.
11, these contact edges 430 and 440 have a thickness selected to
ensure smooth film flow thereover.
[0066] In the unfolded orientation, each of the contact surface,
which include the angled contact edges 430 and 440 (identified as
436 and 446 in the unfolded configuration), portions of the first
and second folding wings 30 and 40, portions of the continuous
entrance surface 50, including the planar panels 52 and 54 and
portions 422 and 424 of the curved side panels 56 and 58, and the
contact surface portions 26, 223, and 225 of the folding tunnel 20
are at or within the width of the film 400. Thus, the length of the
film 400 as its travels across these film contact surfaces in
generally constant between the longitudinal side portions 402 and
404 thereof and across the width 410 of the film 400. As discussed
above, if the length of the film as it contacts the surfaces of the
forming apparatus is generally constant, then the transverse
longitudinal tensile forces in the film likewise will also be
generally constant.
[0067] Minimizing the amount of friction force between the film 400
and forming apparatus 10 during movement of the film 400 across
contact surfaces of the forming apparatus 10 can result in reduced
overall tensions in the film 400, as shown in the chart of FIG. 16.
Sources of friction can include various radii of the contact
surfaces and variations in the contact surfaces.
[0068] To minimize the friction forces, the radii of the contact
surfaces are increased. For example, the forming edges 430 and 440
of the first and second folding wings 30 and 40 have radii selected
to be between 0.05 and 0.15 inches, which results in a spacing of
between about 0.10 and 0.30 inches between outer 32 and 42 and
inner 36 and 46 contact surfaces of the first and second folding
wings 30 and 40.
[0069] To further minimize friction forces, the material used to
make the forming apparatus is preferably selected to have a
strength sufficient to reduce significant wear. In prior forming
systems, such as the prior art integral former of FIGS. 18 and 19,
the material used lacked sufficient strength and durability. A
result of using a material lacking sufficient strength, in part,
can be sharpening of contact edges and other deformations in the
contact surfaces. The prior art integral former also had a chrome
deposition layer, which due to wear could generate minute but sharp
imperfections in the contact surfaces thereof, which could result
in tears or other deformations of the film.
[0070] To address these friction generating concerns, the material
used to make the forming apparatus 10 preferably comprises a
stainless steel, and more preferably comprises 17-4PH steel. The
steel also is preferably heat-treated after being shaped to ensure
sufficient strength. The steel also preferably has a thickness of
about 0.125 inches. The strength and thickness of the steel
eliminates the need for chrome deposition plating, which providing
a strength sufficient to reduce where, thereby minimizing friction
forces caused by flaking of chrome plating and wear of the forming
apparatus 10. In addition, the use of a thicker material allows for
a greater radius to be formed on edges, such as edges 430 and 440
of the folding wings 20 and 40, that comprise contact surfaces with
the film 400. Preferably, all edges in contact with the film 400
are machined to give a smooth radius, thereby reducing
substantially the possibilities of the film slitting. The welds and
other joints between the various components of the forming
apparatus 10 and frame assembly 200 are selected and configured in
order to reduce gaps or spaces in which bacteria can remain. This
assists in ensuring a sterile environment for which the film 400
contacts such surfaces.
[0071] Reducing tensions in the film 400 during the forming into a
sleeve 401, such as by reducing the ratio of tensile forces in the
film 400 at the beginning of the continuous entrance surface 50 and
the end of the forming tunnel 20, by configuring contact surface
geometry to reduce stretching of the film 400, and by minimizing
friction between the film 400 and the forming apparatus 10, can
result in the ability to run thinner films therethrough. For
example, films having a thickness of less than 0.0014 inches, such
as having a thickness of about 0.001 inches, can be run
therethrough, and even lower thicknesses approaching 0.0005 inches
can be run therethrough. When substantial volumes of sleeves 401
are formed using the film, the savings from the reduced thickness
film can be tremendous. Having reduced tensions in the film 400 and
smooth forming thereof into a sleeve 401 also permit the film 400
to be fed through the forming apparatus at higher speeds. For
example, the forming apparatus can optimally be used to form cheese
slices at a rate of about 3,000 slices per minute.
[0072] Certain steps are used in order to form steel sheets into
the various geometric shapes required for the forming apparatus.
These steps include cutting the planar panels 52 and 54, first and
second halves 122 and 124 of the folding tunnel 20, and the curved
side panels 56 and 58 to the appropriate sizes. The sizes may be
determined, in part, by the desired hypothetical unfolded
configuration of the contact surfaces, as illustrated in FIG. 11.
The first and second halves 122 and 124 of the folding tunnel 20
are folded into their end shapes. Next, the folding tunnel 20 and
the panels 52 and 54 are fixed into their final positions using a
jig having attachments for these components. The long edges 66 and
68 of the curved side panels 56 and 58 are then attached to the
lips 53 and 55 of the planar panels 52 and 54. The jig is then used
to apply a bending force to urge the keys 62 and 64 of the into
alignment with the locators 63 and 65 on the first and second
folding wings 30 and 40 of the folding tunnel 20, thereby bending
the panels 56 and 58 into their curved shapes. Welds are made
between the joints of each of the components. The welds are
polished such that they are generally flush with the adjacent
surfaces in order to minimize locations for bacteria and to provide
smooth surfaces over which the film 400 can travel.
[0073] The forming apparatus 10 may be mounted to a frame support
assembly 200 in a horizontal film feed orientation. The frame
support assembly 200 may include a longitudinally extending support
arm 202 having a connection 210 at one end 204 for the filling tube
90 and at the other end 206 for the forming apparatus 10. Having
the filling tube 90 and the forming apparatus 10 connected to a
common support arm 202 advantageously provides assistance in
aligning the filling tube 90 within the forming tunnel 20. The
filling tube 90 extends through the folding tunnel 20, as
illustrated in FIG. 9. The outer surfaces of the filling tube 90
and the inner surfaces of the folding tunnel 20 are sized such that
there is a small space therebetween in order to allow the film 400
to be wrapped around the filling tube 90 by the folding tunnel
20.
[0074] The filling tube 90 has a connection 92 at one end for a
product, such as cheese, to be pumped therethrough and through the
folding tunnel 20 and out the exit 24 and into the sleeve 401
formed by the folding tunnel 20. A release mechanism 212 may be
provided between the connection 210 and the filling tube 90 to
allow the filling tube 90 to be removed from the frame assembly
200, such as to permit cleaning. The high forces due to the pumping
of the product through the filling tube 90 are at least partially
transferred by the common support arm 202 to the folding tunnel 20
to ensure that the space between the outer surfaces of the filling
tube 90 and the inner surfaces of the folding tunnel 20 remains
relatively constant. The connection mechanism 210 may also be
adjustable to allow for precise positioning of the filling tube 90
within the tunnel 20. Pinching of the film 400 between the outer
surfaces of the filling tube 90 and the inner surfaces of the
folding tunnel 20 can be reduced by having a stable connection
between the filling tube 90 and the folding tunnel 20. Moreover,
the sectional profile of the folding tunnel 20 can be closely
matched to the sectional profile of the filling tube 90 in order to
assist in forming a sleeve 401 closely sized to the product exiting
the filling tube 20, as shown in FIG. 12. Shaping the cross-section
of the filling tube 90 closely to that of the cross-section of the
folding tunnel 20 also can result in better control over the slice
width and behavior when the apparatus 10 is used to produce
individually wrapped slices of cheese or other products. The
folding tunnel 20 and folding wings 30 and 40 may be configured to
have minimal overlap between the longitudinal edges 402 and 404 of
the film 400. By comparison, the prior art integral forming
apparatus required much more space between the inner surfaces of
its former and the outer surfaces of its filling tube, as shown in
FIG. 13, in order to provide sufficient tolerance for relative
movement therebetween. Moreover, the prior former of FIG. 13
resulted in a significant overlap of film lateral edges.
[0075] The common support arm 202 is attached to a pivot arm 208.
The pivot arm 208 extends downward from the common support arm 202
to a pivot 210. The pivot 210 is positioned between a bracket arm
214 and the downwardly extending pivot arm 208. The pivot 210
allows the common support member 202 and pivot arm 208 to pivot and
rotate the forming apparatus 10 attached thereto between an upper
position and a lower position. When in the lower position, the
forming apparatus 10 is removed a sufficient distance in order to
allow access to a second forming apparatus 100 that may be mounted
therebehind. The second forming apparatus 100 is similar to the
first forming apparatus 10, having a folding tunnel 120, first and
second folding wings 130 and 140, and a continuous entrance surface
150. The pivoting of the first forming apparatus 10 can
advantageously allow increased accessibility to the second forming
apparatus 100, such as for cleaning and feeding of film
therethrough manually. The bracket arm 214 is attached to multiple
arms that form the remainder of the frame assembly 200.
[0076] The frame 200 includes four bolts for securing the assembly,
including the first and second forming apparatus 10 and 100, to
other machinery. Shims 221 are provided adjacent the bolts in order
to allow for adjustments to be made in the orientation of the
forming apparatus 10 and 100 and frame assembly 200 relative to the
other machinery. For example, different thicknesses of shims 221
can be used to more precisely control the position of the frame
220. In addition, shims 222 may also be used to control the
relative position of the first forming apparatus 10 to the common
support arm 202, as illustrated in FIG. 10. Shims may also be used
to control the relative position of the second forming apparatus
relative to the frame 200.
[0077] The method and apparatus 10 described above is useful in
high speed commercial operations such as a continuous "hot pack"
line wherein individually wrapped cheese slices are formed, such as
by filling the sleeve 401 with cheese using the filling tube 90,
separated, and stacked (such as using the apparatus and methods
disclosed in U.S. Pat. No. 6,595,739, the disclosure of which is
hereby incorporated by reference in its entirety), and an overwrap
is then formed, filled, and sealed around the stack, in a
continuous, in line operation. In this type of process, the cheese
slice may comprise a slice of pasteurized process cheese,
pasteurized process cheese food, pasteurized process cheese spread,
or the like, hot filled into the continuous sleeve to form a ribbon
which is separated into individual wrapped slices. The method and
apparatus of the invention may also be useful with other foods,
such as slices of meat or natural cheese.
[0078] As can be appreciated from the above description of FIGS.
1-20, there is provided a new forming apparatus for forming a film
into a sleeve around a filling tube, which has contact surface
geometry configured to ensure smooth forming of the film into the
sleeve, in part by reducing longitudinal tensile forces in the
film. While there have been illustrated and described particular
embodiments, it will be appreciated that numerous changes and
modifications will occur to those skilled in the art, and it is
intended in the appended claims to cover all those changes and
modifications which fall within the true spirit and scope
thereof.
* * * * *