Patent Publication Number: US-2010126119-A1

Title: Heat activated support system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This utility patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/117,775 filed Nov. 25, 2008, entitled “HEAT ACTIVATED SUPPORT SYSTEM,” the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method of packaging a plurality of items in a flexible container, and more specifically to a flexible container having an expandable material disposed thereon and being activated to increase the rigidity of the expandable material to stabilize the flexible container. 
     2. Description of the Prior Art 
     Flexible containers are used to hold several items together, such as particulate or cartons. An example of a flexible container includes a bag having a top opening for receiving the particulate. The bag further includes a storage compartment for holding the particulate therein. Traditionally, methods of packaging a particulate in a flexible container include moving the particulate through the opening of the flexible container and into a storage compartment. The flexible container may stretch to accommodate the increased volume into the storage compartment. A flexible container can also be comprised of plastic wrap that extends around a plurality of cartons. 
     SUMMARY OF THE INVENTION AND ADVANTAGES 
     The subject invention provides a method for packaging a plurality of particles in a flexible container. The method includes the step of moving the particles through an opening of the flexible container to at least partially fill the flexible container. An expandable material is then disposed, in an unexpanded state, to at least a portion of the flexible container. Next, at least a portion of the expandable material is activated after the moving step has begun to expand the expandable material and increase the rigidity of the expandable material to stabilize the flexible container. 
     The subject invention further provides a method for packaging a plurality of items in a flexible container and begins by stacking a plurality of cartons together. The cartons are then wrapped with a flexible film. Next, an expandable material is disposed, in an unexpanded state, to at least a portion of the flexible film. At least a portion of the expandable material is then activated after the wrapping step has begun to expand the expandable material and to increase the rigidity of the expandable material to stabilize the stack of cartons. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein: 
         FIG. 1  of the application is a simplified flow diagram illustrating the steps of a first exemplary embodiment of the invention; and 
         FIG. 2  of the application is a simplified flow diagram illustrating the steps of a second exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Flexible containers are used to receive and hold a particulate, such as cereal. An example of a flexible container is a bag that includes an opening near the top for receiving the particulate. The bag further includes front, rear and side panels extending vertically along an axis or, for a circular bag, a cylindrical wall extending vertically along the axis. The walls extend from the opening to a closed bottom. The walls and bottom define a storage compartment for holding the particulate therein. The bag can be hung or suspended with the opening facing upward to receive particles. The suspended bag can be described with respect to a vertical axis that extends between the bottom and the opening. 
     According to the exemplary embodiment of the invention, a method for packaging a plurality of particles in a flexible container, shown in  FIG. 1 , starts at step  20 . At step  22 , a plurality of particles are moved through an opening of the flexible container to at least partially fill the flexible container. As an example, the moving step may be accomplished by moving a particulate along a conveyor having the downstream end positioned over the opening of the bag. In addition, the moving step may be accomplished by moving the particulate through a hopper, vertical bagging machine, or any other method known in the art of bagging or packaging. 
     At step  24 , an expandable material, in an unexpanded state, is disposed to at least a portion of the flexible container. The expandable material can be disposed on the bag prior to the bag being suspended. The expandable material can be relatively thin, allowing a plurality of bags at least partially coated with the expandable material rolled on a single roll. The expandable material can be applied by spraying, brushing, screen printing, ink jet, or any other method. The expandable material can be applied to the bag in a pattern, such as a plurality of ribs. Alternatively, the expandable material may be applied in a lattice pattern or in strips that extend parallel to the longitudinal axis of the bag. A non-exclusive list of expandable materials that can be practiced with the invention include the materials disclosed in U.S. Pat. Nos. 7,077,460 and 7,169,344, which are hereby incorporated by reference. 
     At step  26 , the expandable material is activated after the moving step has begun for expanding the expandable material and increasing the rigidity of the expandable material. In the exemplary embodiment of the invention, the activating step may be accomplished by exposing the expandable material to heat, radio frequency radiation, ultraviolet radiation, ultrasonic radiation, electromagnetic fields, or another source that expands the particular expandable material applied to the bag. The activating source expands the polymeric material of the ribs and increases the rigidity of the ribs for stabilizing the bag containing the plurality of particulates. By increasing the stability of the bag after the moving step has begun, instances where the bag topples are decreased. For example, if it appears during filling that the bag is beginning to lean in a direction, the expandable material in that direction can be expanded to counter-act the leaning of the bag. The expansion may be initiated along the entire vertical length of the bag in the direction of leaning if necessary. The method ends at step  28 . 
     In an alternative embodiment of the invention, a plurality of items are packaged in a flexible container in the form of a flexible film as shown in  FIG. 2 , which begins at step  40 . For example, the flexible film may be a stretch wrap roll, a stretch bag, or any other flexible film known in the art. The second embodiment of the broader invention includes the step  42  of stacking a plurality of cartons together. The individual cartons can be any size, can be formed from any material, and can contain any kind of product. The stack fanned with the cartons can have a foot print that is square or rectangular or any other desired shape. The second embodiment of the broader invention also includes the step  44  of wrapping the cartons with a flexible film. The second embodiment of the broader invention also includes the step  46  of disposing an expandable material in an unexpanded state to at least a portion of the flexible film. The expandable material can be disposed in parallel lines on the film, or can be disposed in a grid pattern, or can be disposed in an irregular pattern. The second embodiment of the broader invention also includes the step  48  of activating at least a portion of the expandable material after the wrapping step has begun to expand the expandable material and to increase the rigidity of the expandable material for stabilizing the stack of cartons. The material can be expanded when wrapping is complete or can he started before wrapping complete. The material can be selectively expanded to address locations of the stack that appear vulnerable to collapse or bulging or leaning. 
     In other embodiments of the invention, the flexible container having the expandable material can be disposed in a mold prior to expansion of the material. The mold can cause the material to conform to a desired shaped during expansion. It may be desirable to dispose the flexible container in the mold prior to filling. However, in other embodiments of the invention, it may be desirable to place the filled container in the mold and then expand the material. 
     Turning now to a discussion of the material for use in the present invention, the material can be any material that can be dispensed as a liquid, solid, or semi-solid material and later reacted or cured to create a substantially fused member. The material can be processed and dispensed as a liquid prepolymer or a thermoplastic material before curing, and in one embodiment, after curing the material can become thermoset. The preferred material is a polymeric material, with the most preferred material being a polymeric material that becomes thermoset after curing. Materials that can be used to form the material include, but are not limited to, epoxy, polyurethane, polyester, and acrylic based materials, which when compounded with appropriate ingredients may expand and cure in a reliable and predictable manner upon application of a curing stimulus. One of skill in the art will appreciate the various olfenic materials, elastomers, fluropolymers or other materials that may be used to formulate the material. 
     A number of epoxy-based structural reinforcing foams are known in the art and may also be used to produce the material of the present invention. A typical structural foam includes a polymeric base material, such as an epoxy resin or ethylene-based polymer which, when compounded with appropriate ingredients (typically a blowing agent, a curing agent, and perhaps a filler), typically expands and cures in a reliable and predictable manner upon the application of heat or another activation stimulus. The resulting material has a low density and sufficient stiffness to impart desired rigidity to a supported article. From a chemical standpoint for a thermally-activated material, the structural foam is usually initially processed as a thermoplastic material before curing. After curing, the structural foam typically becomes a thermoset material that is fixed and incapable of flowing. 
     The material is generally and preferably a heat-activated epoxy-based resin having foamable characteristics upon activation through the use of heat typically encountered in an e-coat or other automotive paint oven operation. As the material is exposed to heat, it generally expands, cross-links, and structurally bonds to adjacent surfaces. An example of a preferred formulation is an epoxy-based material that may include polymer modificis such as an ethylene copolymer or terpolymer that is commercially available from L&amp;L Products, Inc. of Romeo, Mich., under the designations L-5204, L-5206, L-5207, L-5209, L-5214, and L-5222. One advantage of the preferred structural foam materials over prior art materials is the preferred materials can be processed in several ways. Possible processing techniques for the preferred materials include injection molding, blow molding, thermoforming, direct deposition of palletized materials, extrusion or extrusion with a mini-applicator extruder. This enables the creation of part designs that exceed the design flexibility capability of most prior art materials. In essence, any foamable material imparts structural reinforcement characteristics may be used in conjunction with the present invention. The choice of the material used will be dictated by performance requirements and economics of the specific application and requirements and may not necessarily include a heat-activated expandable material. 
     Additional foamable or expandable materials that could be utilized in the present invention include other materials which are suitable as bonding, energy absorbing, or acoustic media and which may be heat activated foams which generally activate and expand to fill a desired cavity or occupy a desired space or function when exposed to temperatures typically encountered in automotive e-coat curing ovens and other paint operation ovens. Though other heat-activated materials are possible, a preferred heat activated material is an expandable or flowable polymeric formulation, and preferably one that can activate to foam, flow, adhere, or otherwise change states when exposed to the heating operation of a typical automotive assembly painting operation. For example, without limitation, in one embodiment, the polymeric foamable material may comprise an ethylene copolymer or terpolymer that may possess an alpha-olefin. As a copolymer or terpolymer, the polymer is composed of two or three different monomers, i.e., small molecules with high chemical reactivity that are capable of linking up with similar molecules. Examples of particularly preferred polymers include ethylene vinyl acetate, EPDM, or a mixture thereof. Without limitation, other examples of preferred foamable formulations commercially available include polymer-based materials available from L&amp;L Products, Inc. of Romeo, Mich. under the designations as L-2018, L-2105, L-2100, L-7005, L-7101, L-7102, L-2411, L-2420, L-4141, etc. and may comprise either open or closed cell polymeric base material. 
     The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and do come within the scope of the invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims.