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Title:
SEALING APPARATUS FOR MULTILAYER FILM
Document Type and Number:
WIPO Patent Application WO/2012/061507
Kind Code:
A1
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 (7251 Chestnut Court, Warrenton, VA, 20187, US)
FISCHER, Robert (5321 Midland Road, Midland, VA, 22728, US)
DANIEK, V., Michael (334 Singleton Circle, Warrenton, VA, 20186, US)
KENNEDY, James, Ross (6 Seaman Court, Fredericksburg, VA, 22405, US)
MOLKA, Michael (5321 Midland Road, Midland, VA, 22728, US)
Application Number:
US2011/058972
Publication Date:
May 10, 2012
Filing Date:
November 02, 2011
Export Citation:
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Assignee:
ROSS INDUSTRIES, INC. (5321 Midland Road, Midland, VA, 22728, US)
SPILLNER, Wayne (7251 Chestnut Court, Warrenton, VA, 20187, US)
FISCHER, Robert (5321 Midland Road, Midland, VA, 22728, US)
DANIEK, V., Michael (334 Singleton Circle, Warrenton, VA, 20186, US)
KENNEDY, James, Ross (6 Seaman Court, Fredericksburg, VA, 22405, US)
MOLKA, Michael (5321 Midland Road, Midland, VA, 22728, US)
International Classes:
B65B7/28; B65B51/14; B65B61/04
Foreign References:
US20030196412A12003-10-23
US6984442B22006-01-10
US6481185B12002-11-19
US3754372A1973-08-28
US6210725B12001-04-03
Attorney, Agent or Firm:
METJAHIC, Safet et al. (McGuirewoods, LLP1750 Tysons Blvd,Suite 180, Mclean VA, 22102, US)
Download PDF:
Claims:
WHAT IS CLAIMED:

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® or Radel R®; polytetrafluoroethylenes (PTFE); G10 fiberglass laminate; a silicone sheet; a silicone foam;

Synform™; ceramics; poly ether ether ketone (PEEK);

Ultem®;

Fluorosint®; 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-ft2-°F; a glass transition temperature rating of at least about 41 °F; and a continuous operation temperature rating of at least about 285°F.

6. The apparatus of claim 1, wherein the tray insulator comprises a domed shape material comprising Radel® or Radel R®.

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°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® or Radel R®.

17. The assembly of claim 13, wherein the seal bar insulator comprises at least one of:

polyphenylsulfone (PPSU);

Radel® or Radel R®;

polytetrafluoroethylenes (PTFE);

G10 fiberglass laminate;

a silicone sheet;

a silicone foam;

Synform™;

ceramics;

polyether ether ketone (PEEK);

Ultem®;

Fluorosint®;

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°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:
SEALING APPARATUS FOR MULTILAYER FILM

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 November 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® 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 ® and Radel R ® , G10 fiberglass laminate, silicone sheets or foam, Synform™, ceramics, polyether ether ketone (PEEK), Ultem ® , Fluorosint , 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 Al 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® 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® or Radel R®, polytetrafluoroethylenes (PTFE), G10 fiberglass laminate, silicone sheets or silicone foam, Synform®, ceramics, poly ether ether ketone (PEEK), Ultem®, Fluorosint®, 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-°F, a glass transition temperature rating of at least about 415°F, and a continuous operation temperature rating of at least about 285°F. The preferred shape and material for the tray insulator is domed shaped comprising of Radel® or Radel R®.

[0013] The seal bar insulator may include at least one of: a silicone sheet, silicone foam, polyphenylsulfone (PPSU) such as Radel® or Radel R®, polytetrafluoroethylenes (PTFE), G10 fiberglass laminate, Synform®, ceramics, polyether ether ketone (PEEK), Ultem®, Fluorosint®, 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 ½ inches to about 48 inches, a width of about ½ 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°C to about 80°C, and preferably around 60°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™ Junior, Inpack™ Junior Automatic, and the Inpack™ S Series, and may be used specifically with specialty films, including Cryovac Mirabella ® 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. 1 A 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*(AT/d) where: Q = the rate of heat flow

k = thermal conductivity of the material

A = contact area

ΔΤ = temperature difference d = distance of heat flow

[0056] The ideal tray insulator 250 material has a thermal conductivity between about 2.2 to about 2.8 BTU-inch / hr-ft 2 -°F, a glass transition temperature rating of about 415°F or greater, and a continuous operation temperature rating of about 285°F or greater. The tray insulator 250 may be entirely constructed of polyphenylsulfone (PPSU), commercially known as Radel ® and Radel R ® . Radel R ® , or other impact resistant thermoplastic material that can deliver the ideal sealing conditions described above, and that is readily moldable and food use approved.

[0057] The thickness of the Radel R ® insulator (di 2 ) to be used may be calculated using Fourier's equation where all the other variable are known:

E in = E out = Q" = A*AT/∑(R" T ) = A * (T H - T F )

(d I2 /k I2 + dn/kn + d s /k s ) where: E = energy

Q" = the rate of heat flow

A = contact area

ΔΤ = temperature difference

T H = temperature of the heat element

Tp = the surface temperature of the tray insulator 260

di2 = distance of heat flow (thickness) in the tray insulator 260 dii = distance of heat flow (thickness) in the seal bar insulator 240 ds = distance of heat flow (thickness) between the heat element 220 and seal bar insulator 240

k E = thermal conductivity of the tray insulator 260 material

kii = thermal conductivity of the seal bar insulator 240 material ks = thermal conductivity of the seal bar 210 material [0058] The surface temperature of the tray insulator 260 and heating element 230 may be a temperature ranging from about 40°C to about 80°C, and preferably around 60°C. It is noted that surface temperature may include temperatures that are lower than 40°C, or greater than 80°C.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] FIG. 6 shows a front tray side view of the tray insulator 250.

[0064] 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.

[0065] FIG. 7 shows a perspective backside view of the tray insulator of 250.

[0066] 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.

[0067] FIG. 9 shows an example of a knife blade 611 with a serrated edge.

[0068] 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.

[0069] FIG. 10 shows an example of a method for manufacturing an insulator sealing head assembly according to the principles of the disclosure.

[0070] 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).

[0071] 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).

[0072] 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 ® , 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).

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.