U.S. patent application number 13/287769 was filed with the patent office on 2012-08-09 for sealing apparatus for multilayer film.
Invention is credited to V. Michael Daniek, Robert Fischer, James Ross Kennedy, Michael Molka, Wayne Spillner.
Application Number | 20120198797 13/287769 |
Document ID | / |
Family ID | 46024817 |
Filed Date | 2012-08-09 |
United States Patent
Application |
20120198797 |
Kind Code |
A1 |
Spillner; Wayne ; et
al. |
August 9, 2012 |
SEALING APPARATUS FOR MULTILAYER FILM
Abstract
The present disclosure relates to a heat sealing apparatus
including an insulator sealing head assembly and a container
cavity, and a process for manufacturing an insulator sealing head
assembly. The insulator seal head assembly is specifically designed
to accommodate specialty films, such as multilayer film, used to
seal food containers as described herein.
Inventors: |
Spillner; Wayne; (Warrenton,
VA) ; Fischer; Robert; (Midland, VA) ; Daniek;
V. Michael; (Warrenton, VA) ; Kennedy; James
Ross; (Fredericksburg, VA) ; Molka; Michael;
(Midland, VA) |
Family ID: |
46024817 |
Appl. No.: |
13/287769 |
Filed: |
November 2, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61409439 |
Nov 2, 2010 |
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Current U.S.
Class: |
53/477 ;
53/375.9 |
Current CPC
Class: |
B26F 1/40 20130101; B29C
66/919 20130101; B29C 66/24244 20130101; B29C 66/53461 20130101;
B29C 66/91421 20130101; B32B 27/28 20130101; B29C 66/8242 20130101;
B29C 65/18 20130101; B29C 66/8181 20130101; B29C 65/74 20130101;
B29C 66/81821 20130101; B29C 66/242 20130101; B29C 66/8122
20130101; B29C 66/91431 20130101; B29C 66/8122 20130101; B32B
2262/101 20130101; B29C 66/112 20130101; B29C 66/81427 20130101;
B29C 66/81261 20130101; B26D 7/10 20130101; B29C 66/81422 20130101;
B29C 66/8167 20130101; B29C 66/8122 20130101; B32B 5/18 20130101;
B29C 66/8122 20130101; B29C 66/81423 20130101; B29C 66/8122
20130101; B29C 66/8122 20130101; B32B 5/24 20130101; B65B 31/028
20130101; B29C 66/131 20130101; B29K 2879/085 20130101; B29K
2881/06 20130101; B29K 2909/02 20130101; B29K 2883/00 20130101;
B29K 2871/00 20130101; B29K 2827/18 20130101; B29K 2881/00
20130101; B29C 65/305 20130101; B65B 51/14 20130101; B29C 66/81241
20130101; B29C 66/8322 20130101; B29C 66/8122 20130101; B29C 66/723
20130101; B26F 2001/4481 20130101; B29C 66/8122 20130101 |
Class at
Publication: |
53/477 ;
53/375.9 |
International
Class: |
B65B 51/10 20060101
B65B051/10; B65B 7/00 20060101 B65B007/00 |
Claims
1. A heat sealing apparatus configured to receive a container and
to seal the container with a multilayer film, the apparatus
comprising: a container cavity that receives and holds a container;
and an insulator sealing head assembly configured to seal the
container with a multilayer film, wherein the insulator sealing
head assembly comprises: a tray insulator that contacts the
multilayer film; a seal bar insulator that contacts the tray
insulator; and a seal bar that includes a heat element.
2. The apparatus of claim 1, wherein the seal bar insulator is
located between the seal bar on one side and the tray insulator on
the other side.
3. The apparatus of claim 1, wherein the tray insulator comprises a
domed shape.
4. The apparatus of claim 1, wherein the tray insulator comprises
at least one of: polyphenylsulfone (PPSU); Radel.RTM. or Radel
R.RTM.; polytetrafluoroethylenes (PTFE); G10 fiberglass laminate; a
silicone sheet; a silicone foam; Synform.TM.; ceramics; polyether
ether ketone (PEEK); Ultem.RTM.; Fluorosint.RTM.; polysulfone
(PSU); and polyetherimide (PEI).
5. The apparatus of claim 1, wherein the tray insulator comprises:
a thermal conductivity between about 2.2 to about 2.8
BTU-inch/hr-ft.sup.2-.degree. F.; a glass transition temperature
rating of at least about 415.degree. F.; and a continuous operation
temperature rating of at least about 285.degree. F.
6. The apparatus of claim 1, wherein the tray insulator comprises a
domed shape material comprising Radel.RTM. or Radel R.RTM..
7. The apparatus of claim 1, wherein the seal bar contains three
heat elements.
8. The apparatus of claim 1, wherein the heat elements heats the
surface of the seal bar, and wherein a surface temperature of a
surface of the tray insulator is maintained at about 60.degree.
C.
9. The apparatus of claim 1, wherein the tray insulator and seal
bar insulator are secured to a sidewall of the seal bar.
10. The apparatus of claim 1, further comprising a modified
atmosphere packaging (MAP) vacuum porthole or pathways.
11. The apparatus of claim 1, wherein the sear bar comprises a
cutter that contacts the multilayer film or container and cuts the
film or container.
12. The apparatus of claim 1, wherein the cutter comprises a knife
blade, the knife blade comprising a smooth edge or a serrated
edge.
13. An insulator sealing head assembly for sealing a multilayer
film to a container, the assembly comprising: a tray insulator that
contacts the multilayer film; a seal bar insulator that contacts
the tray insulator; and a seal bar that includes a heat
element.
14. The assembly of claim 13, wherein the seal bar insulator is
located between the seal bar on one side and the tray insulator on
the other side.
15. The assembly of claim 13, wherein the tray insulator comprises
a domed shape.
16. The assembly of claim 13, wherein the tray insulator comprises
a Radel.RTM. or Radel R.RTM..
17. The assembly of claim 13, wherein the seal bar insulator
comprises at least one of: polyphenylsulfone (PPSU); Radel.RTM. or
Radel R.RTM.; polytetrafluoroethylenes (PTFE); G10 fiberglass
laminate; a silicone sheet; a silicone foam; Synform.TM.; ceramics;
polyether ether ketone (PEEK); Ultem.RTM.; Fluorosint.RTM.;
polysulfone (PSU); and polyetherimide (PEI).
18. The assembly of claim 13, wherein the heat elements heats the
surface of the seal bar, and wherein a temperature of a surface of
the tray insulator is maintained at about 60.degree. C.
19. The assembly of claim 13, wherein the tray insulator and seal
bar insulator are secured to a sidewall of the seal bar.
20. A method of manufacturing an insulator sealing head assembly,
the method comprising: providing a tray insulator configured to
contact a multilayer film; providing a seal bar insulator
configured to contact the tray insulator; providing a seal bar that
includes a heat element; and assembling the tray insulator, seal
bar insulator and seal bar.
21. The method of claim 20, wherein the assembling comprises:
positioning the seal bar insulator between the tray insulator and
seal bar; and fastening the tray insulator to the seal bar
insulator and seal bar.
Description
CROSS REFERENCE TO PRIOR APPLICATIONS
[0001] This application claims priority and the benefit thereof
from a U.S. Provisional Application No. 61/409,439 filed on Nov. 2,
2010 and titled SEALING FILM AND METHOD FOR MAKING THE FILM, the
entire contents of which are herein incorporated by reference in
their entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to a heat sealing apparatus
including an insulator sealing head assembly, and a method for
manufacturing an insulator sealing head assembly.
BACKGROUND OF THE DISCLOSURE
[0003] The packaging industry, specifically, the food packaging
industry has been improving upon and creating shallower food trays
in order to best display the food product when packaged and create
a vision of a fuller package from the consumer's perspective. The
use of a shallower food tray also reduces the amount of packaging
materials used.
[0004] The food packaging industry has also been improving upon and
creating new innovative lidding/sealing materials (or film) for use
with the food trays in order to better improve the overall package
appearance to the consumer. Food packaging is known to affect
product sales to consumers, and excellent visual presentation may
be a key factor in increasing product sales. Food packaged in
conventional trays and seals may discolor when the food comes into
contact with the sealing material. Industry has long used modified
atmospheric packaging (MAP), a process used to prolong the shelf
life of unprocessed foods. In MAP, the air surrounding the food
product in the tray is evacuated and replaced with a modified gas
mixture. If the atmosphere in the food packaging is not properly
maintained, it can discolor the food product or create a cloudy
appearance, making the food product visually unappealing.
[0005] Some of the new specialty films being developed for these
purposes include multilayer films, such as the Cryovac
Miribella.RTM. film. However, multilayer film requires specialized
tools to properly cut and shape the sealing material since the film
consists of at least two layers which must be shrink-wrapped to
seal the food tray. The temperature during the sealing process as
well as the shape of the sealing tool will affect the overall
presentation of the sealed package. If all of the layers of the
film are not heated properly, the sealed package may appear to have
film creases, blemishes, streaks or other visible flaws, making the
food product visually unappealing.
[0006] A need exists for a heat sealing apparatus, including an
insulator sealing head assembly that can properly and most
efficiently handle, cut and shape the specialty films being used on
food packaging while maintaining the proper atmospheric conditions
in the food packing.
SUMMARY OF THE DISCLOSURE
[0007] The present disclosure relates to a heat sealing apparatus
including an insulator sealing head assembly, and a process for
manufacturing an insulator sealing head assembly. The insulator
seal head assembly is specifically designed to accommodate
specialty films, such as multilayer films, used to seal food
containers. The insulators in the insulator sealing head assembly
may be constructed from various materials including
polytetrafluoroethylene (PTFE), polyphenylsulfone (PPSU) such as
Radel.RTM. and Radel R.RTM., G10 fiberglass laminate, silicone
sheets or foam, Synform.TM., ceramics, polyether ether ketone
(PEEK), Ultem.RTM., Fluorosint.RTM., polysulfone (PSU),
polyetherimide (PEI), and other insulator-type materials, that are
food-approved, readily-machined, smooth, and stable at high
temperatures.
[0008] The disclosure may be used with, e.g., the systems described
in U.S. Published Patent Application 2011/0072764 A1 by inventors
V. Michael Daniek, et al., which discloses an apparatus, a system
and a method for sealing containers and which is incorporated
herein by reference in its entirety. The present disclosure may be
implemented with the apparatus, system, and method described in the
published application to effectively seal containers with specialty
film, such as multilayer film, including the Cryovac Miribella.RTM.
film.
[0009] According to an aspect of the disclosure, a heat sealing
apparatus may be configured to receive a container and may seal the
container with a lidding such as multilayer film. The apparatus may
comprise of at least one container cavity to hold at least one
container, and an insulator sealing head assembly configured to
seal at least one container with a lidding, such as multilayer
film. The insulator sealing head assembly may comprise: a tray
insulator; a seal bar insulator; a seal bar containing at least one
heat element; a seal bar arm; and a seal bar arm support. The
insulator seal head assembly may comprise a dome shape.
[0010] The insulator sealing head assembly may be configured such
that the seal bar insulator can be located between the seal bar on
one side and the tray insulator on the other side. The tray side of
the tray insulator may be designed to conform to the shape of the
tray being sealed. The tray insulator may comprise of a domed
shape, a circular shape, a square shape, a rectangular shape, an
elliptical shape, a pyramid shape, a triangular shape, or the
like.
[0011] The tray insulator may comprise a material that is made from
at least one of: polyphenylsulfone (PPSU) such as Radel.RTM. or
Radel R.RTM., polytetrafluoroethylenes (PTFE), G10 fiberglass
laminate, silicone sheets or silicone foam, Synform.RTM., ceramics,
polyether ether ketone (PEEK), Ultem.RTM., Fluorosint.RTM.,
polysulfone (PSU), polyetherimide (PEI), or combinations
thereof.
[0012] The material used as the tray insulator may have a preferred
thermal conductivity between about 2.2 to about 2.8
BTU-inch/hr-ft2-.degree. F., a glass transition temperature rating
of at least about 415.degree. F., and a continuous operation
temperature rating of at least about 285.degree. F. The preferred
shape and material for the tray insulator is domed shaped
comprising of Radel.RTM. or Radel R.RTM..
[0013] The seal bar insulator may include at least one of: a
silicone sheet, silicone foam, polyphenylsulfone (PPSU) such as
Radel.RTM. or Radel R.RTM., polytetrafluoroethylenes (PTFE), G10
fiberglass laminate, Synform.RTM., ceramics, polyether ether ketone
(PEEK), Ultem.RTM., Fluorosint.RTM., polysulfone (PSU),
polyetherimide (PEI), or combinations thereof. The seal bar
insulator may comprise a rectangular shape or other geometries as
available or machined, with a length of about 1/2 inches to about
48 inches, a width of about 1/2 inches to about 36 inches and depth
or thickness of about up to 6 inches. The preferred materials for
the seal bar insulator is silicone sheet or silicone foam.
[0014] The material used to form the seal bar may comprise, e.g.,
aluminum, aluminum alloy, tin, lead, cast iron, steel, or
combinations thereof. The seal bar contains at least one heat
element in contact with the seal bar. The heat element(s) may be
constructed of metal or other materials that are useful for heat
transfer and may be heated using, e.g., electricity, or other known
means in the industry.
[0015] The seal bar may be heated by at least one heat element that
heats the surface of the seal bar, where the seal bar comes into
contact with the multilayer film and/or container. The tray
insulator's surface may be maintained at a temperature ranging
from, e.g., about 40.degree. C. to about 80.degree. C., and
preferably around 60.degree. C.
[0016] The tray insulator and seal bar insulator may be secured to
the seal bar from the tray side with at least one, but preferably a
plurality of fasteners, which may include, e.g., a screw, a nut, a
bolt, a clip, a clamp, a pin, a rod, an adhesive, a welding, a
tongue and groove combination, a hook and loop fastener, a lip, or
the like. Alternatively, the tray insulator and seal bar insulator
may be secured to one or more side walls of the seal bar using the
above-mentioned fasteners. The method of mounting the insulators to
the seal bar may comprise mounting and securing the insulators from
the tray side. Alternatively, the insulators may be secured from
the sides of the seal bar, which may result in a smoother machined
domed surface that may not be disturbed with countersunk holes to
secure it in position.
[0017] The tray insulator may comprise one or more vacuum or
modified atmosphere packaging (MAP) vacuum portholes and pathways
to evacuate atmospheric air from the sealed container, and to
insert modified atmospheric gas. The vacuum or MAP
portholes/pathways may be provided on at least the back side of the
tray insulator. The vacuum portholes may also run throughout the
seal bar insulator and the seal bar.
[0018] The seal bar may comprise a cutter, which may include a
heating element. The cutter may be located at the ends of the seal
bar. The heating element may come into contact with the multilayer
film and/or container. The cutter may be shaped to cut the film and
seal the container or surround the container with the film.
[0019] The cutter may include a knife. The knife may comprise a
heated, unheated, or cooled knife blade. The knife blade may be
attached to the seal bar to cut the film and/or a portion of the
container. The knife blade may comprise a smooth edge, a serrated
edge or combinations thereof.
[0020] According to a further aspect of the disclosure, a process
for manufacturing an insulator sealing head assembly is also
disclosed. The process may comprise: providing a mold for a seal
bar, pouring or injecting into the mold a seal bar material, curing
the mold for a predetermined period of time, removing the seal bar
from the mold, providing a mold for a seal bar insulator, pouring
or injecting into the mold a seal bar insulator material, curing
the mold for a predetermined period of time, removing the seal bar
insulator from the mold, providing a mold for a tray insulator,
pouring or injecting into the mold a tray insulator material,
curing the mold for a predetermined period of time, removing the
tray insulator from the mold, positioning the seal bar insulator
and tray insulator to the seal bar, and securing the seal bar
insulator and tray insulator to the seal bar. The process may
further comprise positioning a knife blade to the seal bar, and
securing the knife blade to the seal bar.
[0021] The process for making a seal bar, seal bar insulator and
tray insulator may occur concurrently or sequentially as described
above. In addition, the process may be manual, or a computer
readable medium that comprises a computer program that, when
executed on a computer, may control the entire process as described
above or certain aspects of the process.
[0022] The disclosed insulator sealing head assembly may be
provided with new tray sealer machines, or may be provided as an
adaptable module to existing tray sealer machines. This disclosure
may readily be adapted for use with existing tray sealing machines,
including, e.g., the Ross Inpack.TM. Junior, Inpack.TM. Junior
Automatic, and the Inpack.TM. S Series, and may be used
specifically with specialty films, including Cryovac Mirabella.RTM.
film.
[0023] Additional benefits of the disclosed insulator sealing head
assembly include a better temperature controlled environment and
improved sealed package appearance. The disclosed invention is
better equipped to handle specialty films such as multilayer films,
and can create a smooth domed surface film which can be properly
supported while being applied to the tray, and properly supported
as the package is evacuated of air and modified atmospheric gas
inserted, thereby creating a wrinkle-free and blemish-free seal.
Also, the disclosure of a knife blade with heated serrated edges
can improve the cutting capabilities and reduce fraying or
stretching of the film, thereby increasing the sealed package
appearance.
[0024] Additional features, advantages, and embodiments of the
disclosure may be set forth or apparent from consideration of the
detailed description and drawings. Moreover, it is to be understood
that the foregoing summary of the disclosure and the following
detailed description and drawings are exemplary and intended to
provide further explanation without limiting the scope of the
disclosure as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are included to provide a
further understanding of the disclosure, are incorporated in and
constitute a part of this specification, illustrate embodiments of
the disclosure and together with the detailed description serve to
explain the principles of the disclosure. No attempt is made to
show structural details of the disclosure in more detail than may
be necessary for a fundamental understanding of the disclosure and
the various ways in which it may be practiced. In the drawings:
[0026] FIG. 1 shows an example of a heat sealing apparatus that is
constructed according to the principles of the disclosure;
[0027] FIG. 1A shows a detailed view of the layers of a multilayer
film that can be used with the heat sealing apparatus of FIG.
1.
[0028] FIG. 2 shows a side view of the heat sealing apparatus of
FIG. 1;
[0029] FIG. 2A shows a cross-sectional view of the heat sealing
apparatus of FIG. 2;
[0030] FIG. 3 shows an example of a domed insulator and sealing
head of the apparatus of FIG. 1;
[0031] FIG. 4 shows a perspective tray side view of the tray
insulator of FIG. 1;
[0032] FIG. 5 shows an exploded perspective view of the tray
insulator of FIG. 4;
[0033] FIG. 6 shows a front tray side view of the tray insulator of
FIG. 4;
[0034] FIG. 7 shows a perspective backside view of the tray
insulator of FIG. 4;
[0035] FIG. 8 shows a cross-sectional view of the tray insulator
and the domed tray insulator in the insulator sealing head assembly
of FIG. 3;
[0036] FIG. 9 shows an example of a knife blade with a serrated
edge; and
[0037] FIG. 10 shows an example of a process for manufacturing an
insulator sealing head assembly according to the principles of the
disclosure.
[0038] The present disclosure is further described in the detailed
description that follows.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0039] The disclosure and the various features and advantageous
details thereof are explained more fully with reference to the
non-limiting embodiment and example that is described and/or
illustrated in the accompanying drawings and detailed in the
following description. It should be noted that the features
illustrated in the drawings are not necessarily drawn to scale, and
features of one embodiment may be employed with other embodiments
as the skilled artisan would recognize, even if not explicitly
stated herein. Descriptions of well-known components and processing
techniques may be omitted so as to not unnecessarily obscure the
embodiments of the disclosure. The example used herein is intended
merely to facilitate an understanding of ways in which the
disclosure may be practiced and to further enable those of skill in
the art to practice the embodiments of the disclosure. Accordingly,
the example and embodiment herein should not be construed as
limiting the scope of the disclosure. Moreover, it is noted that
like reference numerals represent similar parts throughout the
several views of the drawings.
[0040] A "computer", as used in this disclosure, means any machine,
device, circuit, component, or module, or any system of machines,
devices, circuits, components, modules, or the like, which are
capable of manipulating data according to one or more instructions,
such as, for example, without limitation, a processor, a
microprocessor, a central processing unit, a general purpose
computer, a super computer, a personal computer, a laptop computer,
a palmtop computer, a notebook computer, a desktop computer, a
workstation computer, a server, or the like, or an array of
processors, microprocessors, central processing units, general
purpose computers, super computers, personal computers, laptop
computers, palmtop computers, notebook computers, desktop
computers, workstation computers, servers, or the like.
[0041] A "computer-readable medium", as used in this disclosure,
means any medium that participates in providing data (for example,
instructions) which may be read by a computer. Such a medium may
take many forms, including non-volatile media, volatile media, and
transmission media. Non-volatile media may include, for example,
optical or magnetic disks and other persistent memory. Volatile
media may include dynamic random access memory (DRAM). Transmission
media may include coaxial cables, copper wire and fiber optics,
including the wires that comprise a system bus coupled to the
processor. Transmission media may include or convey acoustic waves,
light waves and electromagnetic emissions, such as those generated
during radio frequency (RF) and infrared (IR) data communications.
Common forms of computer-readable media include, for example, a
floppy disk, a flexible disk, hard disk, magnetic tape, any other
magnetic medium, a CD-ROM, DVD, any other optical medium, punch
cards, paper tape, any other physical medium with patterns of
holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, any other memory
chip or cartridge, a carrier wave as described hereinafter, or any
other medium from which a computer can read.
[0042] Various forms of computer readable media may be involved in
carrying sequences of instructions to a computer. For example,
sequences of instruction (i) may be delivered from a RAM to a
processor, (ii) may be carried over a wireless transmission medium,
and/or (iii) may be formatted according to numerous formats,
standards or protocols, including, for example, WiFi, WiMAX, IEEE
802.11, DECT, 0G, 1G, 2G, 3G or 4G cellular standards, Bluetooth,
or the like.
[0043] The terms "including", "comprising" and variations thereof,
as used in this disclosure, mean "including, but not limited to",
unless expressly specified otherwise.
[0044] The terms "a", "an", and "the", as used in this disclosure,
means "one or more", unless expressly specified otherwise.
[0045] Although process steps, method steps, algorithms, or the
like, may be described in a sequential order, such processes,
methods and algorithms may be configured to work in alternate
orders. In other words, any sequence or order of steps that may be
described does not necessarily indicate a requirement that the
steps be performed in that order. The steps of the processes,
methods or algorithms described herein may be performed in any
order practical. Further, some steps may be performed
simultaneously.
[0046] When a single device or article is described herein, it will
be readily apparent that more than one device or article may be
used in place of a single device or article. Similarly, where more
than one device or article is described herein, it will be readily
apparent that a single device or article may be used in place of
the more than one device or article. The functionality or the
features of a device may be alternatively embodied by one or more
other devices which are not explicitly described as having such
functionality or features.
[0047] FIG. 1 shows an example of a heat sealing apparatus 100 that
is constructed according to the principles of the disclosure. FIG.
1A shows the layers of a multilayer film 400 that can be used with
the heat sealing apparatus 100.
[0048] Referring to FIG. 1 and FIG. 1A, the heat sealing apparatus
100 is designed to improve sealing and cutting methods for
specialty films, such as a multilayer film 400 where both Layer 1,
the top layer of the film 400, and Layer 2, the bottom layer of the
film 400, must be shrunk with precision to or around (or in) the
tray located in a container cavity 300. The insulator sealing head
assembly 200 comprises a seal bar 210 containing at least one heat
element 220. In the example of FIG. 1, the apparatus 100 comprises
three heat elements 220 evenly located within the seal bar 210. The
heat elements 220 may be heated using electricity or other known
means, and may be made from any metal or metal composite useful for
effective heat transfer to the seal bar 210. The insulator sealing
head assembly 200 may be designed with a seal bar insulator 240
positioned between the seal bar 210 and the tray insulator 250. The
tray facing side 260 of the tray insulator 250 may be shaped so as
to provide ideal film sealing of the tray. In an embodiment, the
tray facing side 260 is domed shaped to produce a domed and smooth
appearance in the film 400 lidding. In addition to the multilayer
film 400, the heat sealing apparatus 100 may be used with other
existing specialty and high tech films and other types of lidding
materials available on the market as of the writing of this
application.
[0049] The seal bar arm 270 may be attached to the seal bar 210
using a seal bar arm support 280. The seal bar 210 and seal bar arm
270 may be constructed of aluminum, aluminum alloy, tin, lead, cast
iron, steel, or combinations thereof. The insulator sealing head
assembly 200 may be operated by manual, pneumatic, hydraulic, or
electronic means by pushing the seal bar arm 270 down and pressing
the insulator sealing head assembly 200 onto the multilayer film
400 until the film is in contact with the tray located in the
container cavity 300 and the film 400 seals to the tray along the
heating element edge 230.
[0050] FIG. 2 shows a side view of the heat sealing apparatus 100.
FIG. 2A shows a cross-sectional view of the heat sealing apparatus
100 cut along the lines of 2A.
[0051] Referring to FIG. 2 and FIG. 2A, the insulator sealing head
assembly 200 may be positioned in an existing or a new tray sealing
machine using at least one seal bar fastener 290. The seal bar
fastener 290 may include, for example, ball-bearings, linear
bearings, or the like, to provide low-friction guiding and support
of the seal bar arm 270 as the seal bar arm 270 travels back and
forth or up and down. The seal bar arm 270 may attach to the seal
bar 210 with a seal bar arm support 280 secured firmly with a bolt
285 or other fastening device, including, e.g., a screw, a nut, a
clip, a clamp, a pin, a rod, or the like. The tray insulator 250
may contain at least one vacuum porthole 265, preferably, multiple
vacuum portholes 265 where air may be removed from the sealed tray
via at least one vacuum port 500 and the desired atmospheric
mixture inserted into the sealed tray via a vacuum port 500. There
may be multiple portholes 265 located throughout the insulator
sealing head assembly, the multiple portholes 265 may be positioned
at specific intervals, spaced apart on (or in) the tray insulator
250, as well as the seal bar insulator 240 and seal bar 210. The
portholes 265 may be configured to extract or receive gas
input/output and may have a round shape, as shown. Alternatively,
the portholes 265 may be other shapes such as circular, square,
rectangular, triangular, or any other shape suitable for an
application.
[0052] FIG. 3 shows an example of a domed insulator and sealing
head of the apparatus 100. FIG. 8 shows a cross-sectional view of
the tray insulator and the domed tray insulator in the insulator
sealing head assembly of FIG. 3.
[0053] Referring to FIG. 3, the seal bar 210 in this example shows
the tray side 260 of the tray insulator 250 comprising a domed
shape, with multiple vacuum portholes 265 located throughout the
tray insulator 250. The tray side 260 of the tray insulator 250 may
have other shapes such as, e.g., circular, square, rectangular,
pyramidal, triangular, or any other shape suitable for an
application. FIG. 8 shows an enlarged view of the tray insulator
250 and seal bar insulator 240, showing the vacuum portholes 265 in
the tray insulator 250 aligned with and extending into the seal bar
insulator 240.
[0054] The tray insulator 250 and seal bar insulator 240 comprise
the composite insulator configuration designed to isolate the
multilayer film 400 or other lidding from the seal bar heating
elements 230 in order to best deliver a controlled temperature
environment that supports and shapes the multilayer film 400 or
other lidding as it is sealed to the tray. The seal bar insulator
240 is preferably entirely constructed of silicone foam or silicone
sheets, but may be constructed of silicone rubber, or any other
insulating material.
[0055] The ideal tray insulator material would be readily moldable
via machine, food use approved, and produce ideal film sealing
conditions, causing a steady state heat flow rate throughout the
composite insulator configuration, as calculated by Fourier's heat
transfer equation:
Q=k*A*(.DELTA.T/d) [0056] where: [0057] Q=the rate of heat flow
[0058] k=thermal conductivity of the material [0059] A=contact area
[0060] .DELTA.T=temperature difference [0061] d=distance of heat
flow
[0062] The ideal tray insulator 250 material has a thermal
conductivity between about 2.2 to about 2.8
BTU-inch/hr-ft.sup.2-.degree. F., a glass transition temperature
rating of about 415.degree. F. or greater, and a continuous
operation temperature rating of about 285.degree. F. or greater.
The tray insulator 250 may be entirely constructed of
polyphenylsulfone (PPSU), commercially known as Radel.RTM. and
Radel R.RTM.. Radel R.RTM., or other impact resistant thermoplastic
material that can deliver the ideal sealing conditions described
above, and that is readily moldable and food use approved.
[0063] The thickness of the Radel R.RTM. insulator (d.sub.I2) to be
used may be calculated using Fourier's equation where all the other
variable are known:
E in = E out = Q '' = A * .DELTA.T / .SIGMA. ( R T '' ) = A * ( T H
- T F ) ( d I 2 / k I 2 + d I 1 / k I 1 + d s / k s ) ##EQU00001##
[0064] where: [0065] E=energy [0066] Q''=the rate of heat flow
[0067] A=contact area [0068] .DELTA.T=temperature difference [0069]
T.sub.H=temperature of the heat element [0070] T.sub.F=the surface
temperature of the tray insulator 260 [0071] d.sub.I2=distance of
heat flow (thickness) in the tray insulator 260 [0072]
d.sub.I1=distance of heat flow (thickness) in the seal bar
insulator 240 [0073] ds=distance of heat flow (thickness) between
the heat element 220 and seal bar insulator 240 [0074]
k.sub.I2=thermal conductivity of the tray insulator 260 material
[0075] k.sub.I1=thermal conductivity of the seal bar insulator 240
material [0076] ks=thermal conductivity of the seal bar 210
material
[0077] The surface temperature of the tray insulator 260 and
heating element 230 may be a temperature ranging from about
40.degree. C. to about 80.degree. C., and preferably around
60.degree. C. It is noted that surface temperature may include
temperatures that are lower than 40.degree. C., or greater than
80.degree. C.
[0078] FIG. 4 shows a perspective tray side view of the tray
insulator 250. FIG. 5 shows a perspective unassembled view of the
tray insulator 250.
[0079] Referring to FIG. 4, the tray side 260 of the tray insulator
250 is designed preferably in a domed shape, with at least one, but
preferably multiple (e.g., 8) vacuum portholes 265. The seal bar
210 and heating element edge 230 may be heated by at least one, but
preferably multiple heat elements 220 running in parallel to the
length of the seal bar 210. The heat elements 220 may be configured
perpendicular or diagonal to each other (not shown). FIG. 5 shows
that at least one of the vacuum portholes 212, 242 may extend into
the seal bar 210. The seal bar insulator 240 is positioned between
the seal bar 210 and the tray insulator 250. The insulators 240,
250 may be mounted onto the seal bar 210 using at least one, but
preferably multiple fasteners 251 (e.g., 4 fasteners) to attach the
seal bar 210 to the tray insulator 250. The fasteners 251 may
include, e.g., screws, bolts, nuts, pins, rods, or the like, which
may be aligned with respective fastening mechanisms 252, e.g.,
screw holes, nuts, bolts, pin holes, rod receivers, or the like, in
the tray insulator 250.
[0080] In an alternative embodiment, the insulation system 240, 250
may be secured to the seal bar 210, with at least one fastener 251,
e.g., four fasteners, one on each side. A side mount fastening
method for the insulators 240, 250 may provide a smoother machined
domed surface, smoother film surface contact transitions, isolation
from the inside cavity surfaces of the seal bar 210 and may
eliminate the need for countersunk holes to secure the insulators
240, 250 into position, thereby providing a simpler total assembly.
The fastener(s) 251 may be constructed and positioned along the
sealing head assembly using techniques known by those having
ordinary skill in the art.
[0081] The seal bar 210 may include a cutter portion (cutter),
which may include a heating element edge 230 that may be used to
seal and cut the film onto (or around or in) the tray.
Alternatively, the seal bar 210 may incorporate a knife blade 600
into its design to improve the cutting experience on, e.g., the
specialty films.
[0082] FIG. 6 shows a front tray side view of the tray insulator
250.
[0083] Referring to FIG. 6, the tray insulator 250 in this example,
shows a tray side mounting of the insulator 250 using four
fasteners 251 with the fastening mechanisms 252 spaced along the
four corners of the domed shaped surface 260. The preferred shape
of the sealing head assembly 200 is rectangular to align with the
shape of the tray to be sealed. It is noted that the tray side
shape of the tray insulator 250, seal bar insulator 240 and seal
bar 210 may be designed and shaped to conform to other tray shapes
such as, e.g., oval, square, circle, or the like.
[0084] FIG. 7 shows a perspective backside view of the tray
insulator of 250.
[0085] Referring to FIG. 7, the backside of the tray insulator 269
shows the backside of the vacuum portholes 265 in the tray
insulator 250 as well as pathways 268 located along the backside.
The number of vacuum portholes 265 and pathways 268 are provided as
necessary to perform modified air packaging (MAP) and support the
film 400 as air is evacuated from the tray package and the modified
atmospheric gas inserted in its place.
[0086] FIG. 9 shows an example of a knife blade 611 with a serrated
edge.
[0087] Referring to FIG. 9, the seal bar 210 may be constructed to
include a knife blade 600. The knife blade 600 may be secured to
the seal bar 210 with a fastener along the fastener holes 612
positioned along and around the knife blade 600. The knife blade
600 may be heated or unheated (or cooled), and may comprise a knife
blade edge 611 that is smooth, serrated saw-tooth like, or some
combination thereof. The knife blade 600 may be positioned along
the seal bar 210 such that the knife blade edge 611 properly cuts
the film where the knife blade edge 611 comes into contact with the
film and tray at 230. A heated knife blade 600 with a serrated edge
611 may be implemented in order to deliver a clean cut off of the
film without stretching the film as it seals the tray.
[0088] FIG. 10 shows an example of a method for manufacturing an
insulator sealing head assembly according to the principles of the
disclosure.
[0089] The seal bar process 700 may begin by providing a mold for
the seal bar 210 to a particular location in, e.g., a manufacturing
facility (Step 710). A seal bar material, preferably aluminum, may
be poured or injected into the mold (Step 720) and cured for a
predetermined period of time (Step 730). The seal bar 210 may then
be removed from the mold (Step 740). The process 700 may further
comprise inspecting the resultant seal bar for faults or defects
(Step 750) and either approving or rejecting the seal bar (Step
760).
[0090] The seal bar insulator process 800 may begin by providing a
mold for the seal bar insulator 240 to a particular location in,
e.g., a manufacturing facility (Step 810). A seal bar insulator
material, preferably silicone foam, may be poured or injected into
the mold (Step 820) and cured for a predetermined period of time
(Step 830). The seal bar insulator 240 may then be removed from the
mold (Step 840). The process 800 may further comprise inspecting
the resultant seal bar insulator for faults or defects (Step 850)
and either approving or rejecting the seal bar insulator (Step
860).
[0091] The tray insulator process 900 may begin by providing a mold
or cast blanks for the tray insulator 250 to a particular location
in, e.g., a manufacturing facility (Step 910). Radius and smooth
chordal geometry may be used to machine these cast blanks to
achieve the desired shape, with the tray side shape preferably a
domed shape. A tray insulator material, preferably Radel R.RTM.,
may be poured or injected into the mold (Step 920) and cured for a
predetermined period of time (Step 930). The tray insulator 240 may
then be removed from the mold (Step 940). The process 900 may
further comprise inspecting the resultant tray insulator for faults
or defects (Step 950) and either approving or rejecting the tray
insulator (Step 960).
[0092] The seal bar 210, seal bar insulator 240 and tray insulator
250 processes may be operated concurrently or sequentially. The
seal bar insulator 240 and tray insulator 250 may then be
positioned with the seal bar 210 (Step 1000) and secured together
(Step 1100) by at least one fastener, preferably insulator
fasteners 251.
[0093] The insulator sealing head assembly 200 process may further
comprise positioning a knife blade 600 to the seal bar 210 and
securing the knife blade 600 to the seal bar 210 via placement of
fasteners in the fastener holes 612.
[0094] It is noted that the processes 700, 800, 900 shown in FIG.
10 may be automated and controlled by a computer. In this regard, a
computer readable medium may be provided that contains a computer
program, which when executed on the computer causes the processes
700, 800, 900 in FIG. 10 to be carried out. The computer program
may be tangibly embodied in the computer readable medium,
comprising a code segment or code section for each of the steps in
FIG. 10.
[0095] While the disclosure has been described in terms of
exemplary embodiments, those skilled in the art will recognize that
the disclosure can be practiced with modifications in the spirit
and scope of the appended claims. These examples are merely
illustrative and are not meant to be an exhaustive list of all
possible designs, embodiments, applications or modifications of the
disclosure.
* * * * *