Patent Application
20070154118
The present invention relates to a flexible, inexpensive, evacuable storage device optionally having a resealable opening and a caulking composition. The present invention also relates to a vacuum storage device and a system for vacuum storage.
Flexible, sealable storage devices, such as consumer storage bags are commonly used to store items such as, but not limited to, food. These devices typically have a bag body made from a thin, flexible plastic material and include a resealable closure. While inexpensive and easy to use, these devices also allow a quantity of air to be enclosed with the item being stored. Air within a storage device containing food is not desirable as the air reacts with the food and will cause spoliation. Additionally, when storage bags are placed in a below freezing environment, typically in a freezer, “freezer bum” may also damage the food items. Freezer bum occurs when moisture is drawn from the food item and forms ice, typically on the food item. Freezer bum is reduced when entrapped air is substantially eliminated from the storage device with concomitant contouring of the bag wall of the storage device around the food item. Consequently, less moisture will be drawn out of the food item.
Prior systems that evacuate flexible storage bags typically include a large device having a vacuum unit and a heat sealer structured to bond sheets of plastic together. The user typically cuts a length of plastic from a roll of plastic and uses the heat sealer to form the plastic into a bag with an opening. After an item has been placed in the bag through the opening, the vacuum unit is then used to remove substantially all of the air from the bag and the bag is sealed. Such systems have various disadvantages, including high materials costs due to once-use methodology and rigorous sealing requirements.
In view of the foregoing background, there is need for a vacuum storage system utilizing a portable vacuum device and optionally a resealable, evacuable, flexible storage device. Resealable closure systems are known, for example, interlocking profiles used in plastic bags. However, in a typical resealable closure, engagement of the sealing structures is rarely perfect, leaving gaps in the profile seal. Moreover, during manufacture of reclosable devices, frequently seals at the ends of the reclosable device distort the engaging portions of the closure which can also provide an unsealed region in the closure. As a consequence of these and other problems associated with resealable closures, a bag utilizing a resealable closure may not be air tight. Consequently when a bag utilizing a resealable closure is subjected to a pressure differential, for example, when it is evacuated or when there is a partial pressure differential of a particular gas between the inside and outside of the bag, gas can leak across the resealable closure and enter, or leave the sealed package through the closure. Thus, gases, for example, air may penetrate into a sealed bag, or for example water vapor may leak from a sealed bag. This is especially a problem when the interior of the bag is at a different pressure than the ambient air, for example, when the bag is under a vacuum, or when the bag contains a gas at a higher or lower partial pressure than the gas is present in the ambient.
Accordingly, there is a need for a flexible, resealable storage device wherein the sealing structure has a resistance to fluid permeability under a pressure differential across the sealing device. Moreover, there is a need for a pre-made, inexpensive, flexible, reusable storage device having a valve structured to operate with a portable vacuum pump. Additionally, there is a further need for a resealable closure that provides for reduction in entrapped air, a flexible bag wall to maintain item conformance, and an air tight seal providing reduced permeability to oxygen, atmosphere intrusion or transmission, bacteria, molds and/or other sources of contamination when used in combination with vacuum pump technology. There is also a need for vacuum pump technology which provides for portability and utility in evacuating a food storage flexible package.
These needs, and others, are met by the present invention that provides in one aspect a vacuum system comprising: (a) a vacuum pump having a suction side; (b) a vacuum conduit in fluid communication with said vacuum pump suction side, the vacuum conduit comprising: (i) a gas/liquid separator means; (ii) at least one vacuum valve optionally comprising a caulking compound (also termed herein a caulking composition) disposed therein; (iii) optionally, a standoff structure; (iv) optionally one or more quick-connect means; (c) an evacuable package defining an interior space in fluid communication with said vacuum conduit; and (d) optionally, a resealable closure defining an opening of said evacuable package. In some preferred embodiments the vacuum pump is portable.
In one embodiment, the vacuum system comprises a kit containing in one assembly the vacuum pump, a liquid separator means and a portion of the vacuum conduit terminated with one portion of a quick-connect means, and in a second assembly, an additional portion of the vacuum conduit comprising a cooperating portion of the quick-connect means, a vacuum valve, an evacuable package and optionally a stand-off structure. In some preferred embodiments, the vacuum pump assembly is provided in a break-apart form wherein one portion of the system comprises the vacuum pump integrally assembled with some portions of the vacuum conduit, for example, the liquid/gas separator, terminating in a quick-connect means, and the remaining portions of the vacuum conduit are provided integral with the evacuable storage package, for example, a vacuum valve having a cooperating quick-connect means arranged in the remaining portion of the vacuum conduit and integral with the flexible package and optionally a stand-off structure.
In one embodiment the standoff structure comprises an embossed plastic sheet having a channel side and a projection side. In one embodiment the standoff structure is positioned within the evacuable package having the channel side in fluid communication with the vacuum conduit and vacuum valve, and having the projection side proximal to the interior space defined by the package.
In another aspect, the present invention provides an evacuable storage package defining an interior space, a vacuum valve in fluid communication therewith, optionally a standoff structure in fluid communication with the vacuum valve, and optionally a resealable closure defining an opening into the interior space of the package wherein the resealable closure comprises at least one set of interengaging profiles.
In some embodiments the resealable closure defining the opening of the inventive storage package comprises at least one pair of opposed interengaging profiles wherein at least one of said interengaging profiles has associated therewith a portion of the closure comprising a low density sealing material, thus providing a region in the closure having a high degree of conformance with the associated interengaging portion of the closure and as well as insuring that when the closure is end-sealed, a gap free seal is provided. In some embodiments the sealing material comprises a portion of one or both interengaging profiles. In some embodiments the sealing material comprises a portion of the flange or of a post of the closure. In some embodiments the sealing material comprises the entire length of the profiles. In some embodiments the sealing material comprises selected portions of the profiles, such as the periphery portions of one or both of the interengaging profiles. In some embodiments the portion of the closure comprising the sealing material is made from a polyolefin material having a density of not more than 0.925 g/cm3, as defined according to ASTM D1505-03, entitled “The standard test method for density of plastics by density gradient techniques”, Book of Standards Volume 08.01 (2005). In some embodiments the resealable closure is used in conjunction with a caulking composition. In one embodiment of the present invention, the caulking composition acts to fill one or more voids between the interengaging profiles, thus reducing the infiltration of ambient into the storage device when it is sealed and placed in a condition of reduced pressure.
In some embodiments the caulking composition is disposed proximal to the interengaging closure profiles such that it is infiltrated into any gaps existing in the closure when the closure profiles are engaged.
In some embodiments the caulking composition comprises a mixture suitable for at least incidental contact to food items. In some embodiments the caulking composition maintains chemical stability throughout a temperature range suitable for food storage and packaging.
In one embodiment the caulking composition is positioned on the first male profile and/or the first female profile. In one embodiment the caulking composition is placed proximal to the interengaging profiles of the closure in one or more positions that permit it to infiltrate gaps formed in the seal formed by the interengaged profiles, for example, as applied to the ends of the closure near the crush area, and as a continuous bead along the closure either on or between one or more of the interengaging profile portions.
In another embodiment of the present invention, the resealable closure device further comprises at least a second set of interengaging profiles positioned in close proximity and parallel to the first set of interengaging profiles. In one embodiment having multiple pairs of interengaging profiles, in addition to sealing material being positioned between each of the engaged portions of the interengaging profiles, a bead of caulking composition may be positioned within the space separating the substantially parallel sets of interengaging profiles.
In one embodiment, the caulking composition comprises constituents such that it maintains integrity, without decomposition, throughout a temperature range suitable for packaging and food storage. Temperatures suitable for packaging and food storage typically range from approximately −10° F. to approximately +160° F. In one embodiment the caulking composition comprises liquid silicone and a filler, e.g. fumed silica, in proportions to provide a grease with a grease consistency number of approximately 2.0, as characterized by National Lubricating Grease Institute (NGLI) standards. In one embodiment, the caulking composition comprises a soy adhesive, such as Pro-cote® soy polymer available from DuPont™. In another embodiment, the caulking composition comprises soy oils, for example, those available from Cargill™. Industrial Oils & Lubricants. In one embodiment the caulking composition comprises two reactive constituents, each residing on a different portion of the closure, such that when the interengaging profiles of the closure are engaged the two constituents are admixed, providing a reaction product which infiltrates at least one void defined by the interengaging closure profiles.
In one aspect, a vacuum storage bag is provided, the vacuum storage bag including an evacuable package, a vacuum valve integral with the evacuable package, and a plurality of barriers positioned within the evacuable package. The evacuable package comprises at least one polymeric sheet sealed about a portion of its periphery defining first and second panels, an opening and an interior space. Each of the plurality of barriers interconnects a portion of the first panel of the evacuable package to a portion of the second panel of the evacuable package. The plurality of barriers also at least assist in defining at least one channel, which is in fluid communication with the vacuum valve and the interior space of the evacuable package.
The plurality of barriers may be of various configurations. For example, the plurality of barriers may be intermittently located about at least a portion of the periphery of the vacuum valve. In one approach, the vacuum valve is integral with the first panel and the plurality of barriers are intermittently located about at least a portion of the periphery of the vacuum valve. The plurality of barriers may be arranged such that the plurality of barriers define various portions of shapes, such as at least a portion of an ellipse. The plurality of barriers may be interconnected with the evacuable package in any suitable manner. For example, the plurality of barriers may be integral with both the first and second panels of the evacuable package, such as via heat sealing of the first panel to the second panel. Thus, in this embodiment, each of the plurality of barriers may define an uninterrupted span from the first panel to the second panel. In another embodiment, the plurality of barriers may comprise a polymeric material bonded to the interior space of the evacuable package.
In one approach, the plurality of barriers are located proximal at least a portion of the perimeter of the evacuable package. In a particular embodiment, a first portion of the plurality of barriers may be substantially parallel to a lateral side of the evacuable package. In turn, a second portion of the plurality of barriers may be substantially orthogonal to the same lateral side of the evacuable package. In one embodiment, the first portion of the barriers may be interconnected to the second portion of barriers, such as when it is desired to define a corner channel portion of the evacuable package.
In a particular embodiment, the plurality of barriers may define a sealing line, and the sealing line may be transverse to a lateral side of the evacuable package. In one embodiment, the sealing line is visible from the exterior of the evacuable package and facilitates visual confirmation of a fill level for the evacuable package. In a related embodiment, a visual indicator (e.g., color or text) may be co-located with the sealing line and this visual indicator may facilitate visual confirmation of a fill level for the vacuum storage.
The plurality of barriers may be utilized in conjunction with various other components of the vacuum storage bag. In one approach, the storage bag may include a standoff structure positioned within the evacuable package. In one embodiment, the stand-off structure may be located proximal the plurality of barriers. In a particular embodiment, at least some of the plurality of barriers may overlap with the stand-off structure. That is, the plurality of barriers and stand-off structure may be co-located at various portions of the evacuable package. In a particular approach, at least one channel fluidly interconnects the stand-off structure and the vacuum valve, such when the plurality of barriers and/or the geometrical structures of the stand-off structure define the channel.
In one approach, the evacuable package may include a resealable closure comprising at least one set of interengaging profiles that facilitate repeated opening and closing of the evacuable package. This resealable closure may define the opening of the evacuable package. In a particular embodiment, the plurality of barriers may be located between the resealable closure and the vacuum valve. In a related approach, the storage bag may include a grease composition associated with the resealable closure. This grease composition may be positioned on the resealable closure to facilitate sealing of the evacuable package.
In another aspect, the vacuum storage bag may include materials to facilitate wicking of liquids contained therein. In one approach, the vacuum storage bag includes a wicking material in fluid communication with the interior space of the evacuable package. In one embodiment, this wicking material may be interconnected to at least one of the first panel and second panel of the evacuable package. For example, the wicking material may be adhesively bonded to at least one of the first panel and second panel of the evacuable package. In another embodiment, to restrict movement of the wicking material within the evacuable package, a plurality of barriers, such as those described above, may be utilized. In one embodiment, the vacuum storage bag includes a plurality of barriers proximal the periphery of the wicking material and surrounding at least a portion of the wicking material. In this embodiment, the plurality of barriers may define a wicking section of the evacuable package and restrict movement of the wicking material from this wicking section. As described above, the plurality of barriers may at least assist in defining at least one channel, this at least one channel being adapted to facilitate liquid communication between the interior space of the evacuable package and the wicking material. The wicking material may be any suitable material adapted to adsorb or absorb liquids, such as desiccants, cellulose-based materials, and others.
As noted above, the resealable closure generally facilitates repeated opening and closing of the evacuable package. The resealable closure may also include structures to facilitate removal of air from the evacuable package. In one aspect, the resealable closure may include a first flexible flange interconnected to the first panel of the evacuable package, the first flexible flange including a first interengaging profile. The resealable closure may further include a second flexible flange interconnected to the second panel of the evacuable package and opposite the first flexible flange. The second flexible flange may include a top portion and a skirt portion, the skirt portion being interconnected to/integral with the top portion. The top portion of the second flexible flange may include a second interengaging profile adapted to restrictably engage the first interengaging profile. The skirt portion of the second flexible flange may include one or more structures for facilitating removal of gases from the evacuable package. In one embodiment, the skirt portion may include a stand-off structure (e.g., an embossed structure). Thus, gases proximal the resealable closure may be more readily removed from the evacuable package via the channels of the skirt portion stand-off structure.
In another embodiment, the skirt portion may include a vacuum valve interconnected therewith. In this regard, the vacuum valve may be integral with the skirt portion of the second flexible flange. To facilitate attachment of the vacuum valve, the skirt portion of the second flexible flange may include differing materials and/or thicknesses relative to the top portion of the second flexible flange. For example, the top portion of the second flexible flange may include low density polyethylene (LDPE) and the skirt portion may include medium density polyethylene (MDPE). In a related approach, the top portion of the second flexible flange may include a first thickness and the skirt portion may include a second thickness that is greater than the first thickness. In a particular embodiment, the top portion comprises a thickness of not greater than about 3 mil, and the skirt portion of the second flexible flange comprises a thickness of at least about 10 mils. In another related approach, the ratio of the thickness of the skirt portion to the thickness of the top portion may be tailored to facilitate interconnection of structures to the skirt portion of the second flexible flange while restricting the thickness of the top portion. For example, the ratio of the thickness of the skirt portion to the thickness of the top portion may be at least about 1.5:1.
The skirt portion may also include non-structured portions. For example, the skirt portion may include non-textural portions adjacent a lateral edge of the skirt portion. These non-textured portions may facilitate sealing of the evacuable package about the periphery.
Methods for forming resealable closures comprising structures are also provided. In one approach, the method includes the step of feeding at least a portion of the resealable closure through an anvil and an embossing wheel, and contacting at least some of the skirt portion of the resealable closure with an embossing portion of an embossing roll. The embossing roll may include structures that facilitate development of the stand-off structure (e.g., protrusions and/or cavities). The method may also include the step of contacting the skirt portion of the resealable closure with a non-embossed portion of the embossing roll to facilitate production of non-embossed portions of the skirt portion of the resealable closure.
As may be appreciated, various aspects, approaches and/or embodiments noted hereinabove may be combined to yield various different configurations of the vacuum storage system and corresponding methods. These and other aspects, advantages, and novel features of the invention are set forth in part in the description that follows and will become apparent to those skilled in the art upon examination of the following description and figures, or may be learned by practicing the invention.
a is a front view of one of embodiment of a storage device.
b is a side, cross-sectional view of one embodiment of a storage device.
a-10c are front views of embodiments of stand-off structures.
a-11c are isometric views of embodiments of stand-off structures.
a-12b are cross-sectional views of embodiments of stand-off structures.
a-13d are isometric views of embodiments of a storage device in an unfolded condition.
a-16b illustrate the front view of one embodiment of a closing clip and the side view of the closing clip.
a-22d illustrate various embodiments of an evacuable package having a barrier structure.
a-25c illustrate various views of one embodiment of a resealable closure including a stand-off structure and an interconnected vacuum valve assembly.
a is a perspective view of one embodiment of a process for producing a resealable closure having a vacuum valve interconnected therewith.
b is a perspective view of one embodiment of a process for producing a plurality of resealable closures, each having a vacuum valve interconnected therewith.
The present invention is now discussed in more detail referring to the drawings that accompany the present application. In the accompanying drawings, like and/or corresponding elements are referred to by like reference numbers. In one embodiment of the present invention, a vacuum system is provided that may include a portable vacuum pump and an evacuable package in communication through a vacuum conduit. The evacuable package may optionally include a stand-off structure and a resealable closure having a caulking composition disposed thereon. In one embodiment, the resealable closure comprises interlocking profiles on which the caulking composition is disposed to provide a gas permeation resistant seal in the resealable closure. The vacuum conduit provides communication between the portable pump and the storage portion of the evacuable bag, wherein the vacuum conduit comprises at least a valve assembly and optionally a stand-off structure. In one embodiment, the stand-off structure provides a means to substantially eliminate the incidence of trapped air within the storage area of the evacuable package. Each of the aspects of the interlocking profiles, the caulking composition, the vacuum valve assembly, the stand-off structure, and the vacuum pump are now discussed in greater detail.
Referring to
In one embodiment of the present invention, the evacuable package 14 may be a multilayer bag comprising an inner sealant layer and a barrier/strength layer. The inner sealant layer may comprise LDPE (low density polyethylene) or LLDPE (linear low density polyethylene) and the barrier/strength layer may comprise Nylon, PP (polypropylene) or PET (Polyester). As used herein the term “low density” in conjunction with polyethylene denotes a material having a density of no greater than 0.925 g/cm3, as defined by ASTM standard D-15005-03, wherein the density may be adjusted with the addition of ethylene vinyl acetate (EVA). Another example of a multilayer bag and a method of forming a multilayer bag is described in U.S. Pat. No. 4,267,960, titled “Bag For Vacuum Packaging of Meats or Similar Products”, filed Aug. 29, 1979, which is incorporated herein by reference.
In the embodiments of the present invention in which the evacuable bag 14 has an opening 18 to the storage space 22, the bag opening 18 includes a resealable closure 20. The resealable closure 20 may include a set of interlocking profiles. In one example, the set of interlocking profiles 21 may include resilient, selectively engaging male and female profiles 21 (tongue-and-groove closure), structured to seal the opening 18. It will be appreciated that there are numerous interlocking profile geometries known, which can be employed in the present invention.
With reference to
Still referring to
As discussed above, the bead of sealing material 66 may have a lower density than the protrusions 54, 56, 58, 62, 64. During the engagement of resealable closure 20, the lower density and hence more compliant bead of sealing material 66 conforms to the geometry of the higher density and more rigid material comprising the portion of the closure against which the head of the profile abuts upon engagement. The softer material abuts the closure with increased conformance to the abutting surface, advantageously providing a more effective seal against fluid exchange between the interior of the package and the ambient, for example, the intrusion of gas and the exterior atmosphere into the evacuable bag 14. Regardless of the above described embodiments, the resealable closure 20 and its associated interlocking structures can comprise resilient materials of varying densities and melt indexes. Accordingly, embodiments within the scope of the present disclosure, including combinations of materials selected to achieve sealant conditions under vacuum and reduced temperature conditions.
The protrusions forming the male profile may also be referred as a profile having a male head. The protrusions defining the female profile (also referred to as a groove) may also be referred to as profile having a female head and a fillet positioned to provide a groove. The resealable closure 20 may further include a closing clip structured to ensure the complete engagement of the closure profiles. Specifically, the closure clip functions to ensure that the interengaging profiles are engaged as the clip is disposed along a first direction, but does not affect the engagement of the profiles when disposed along the direction opposite to that of the first direction.
Regardless of the specific details of construction or interaction of the profiles 21 of resealable closure 20, the interengaging portions of the resealable closure of the present invention preferably includes a caulking composition 99 (also sometimes referred to as sealing compound 99). For example, the caulking composition 99 may be positioned on at least one protrusion 54 on the first flange 50 and/or at least one protrusion 56, 58 on the second flange 52 of the closure 21, wherein the caulking composition 99 assists in creating an air tight seal to the storage space 22. Specifically, during engagement of the first and second flange protrusions 54, 56, 58, 62, 64 of the male and female profiles, the caulking composition 99 sits within the groove 60 to ensure an air-tight seal of the male and female profile. Specifically, the caulking composition 99 is positioned to infiltrate the void space defined between the engaged interlocking profiles 21 of the resealable closure 20. Without being bound by theory, it is believed that that the caulking composition 99 acts to infiltrate gaps between the male and female profiles, thus reducing the infiltration of ambient into the storage device 10 when it is placed in a condition of reduced pressure.
Accordingly, the resealable closure 20 is prepared before sealing by introducing the caulking composition 99 onto one or more members of the interengaging profiles 21 or onto a surface of the resealable closure 20 proximal to the interengaging profiles 21, by methods such as deposition or injection, where it will be distributed during the interlocking process within incipient gaps left between the interengaging profiles 21 after interlocking. Alternately, prior to sealing the resealable closure 20, the caulking composition 99 can be placed proximal to known areas in which the sealing profile is prone to exhibit gapping, for example, the ends of the male and female profiles 21 at the bag's periphery. The portions of the male and female profiles at the bags periphery are engaged by crush seal, which is often the site of leakage in the closure device. The voids caused by the crush seal engagement at the male and female profile may be filled with the sealing compound 99 to substantially reduce the incidence of leakage.
The caulking composition 99 may comprise any material that provides a selectively reversible air tight seal between the interlocking profiles 21 of the resealable closure 20, in which the caulking composition 99 is suitable for at least incidental contact to food items inserted through the opening to the storage space. Preferably, the caulking composition 99 maintains its chemical structure throughout the operable temperature range of storage device 10. The term “suitable” for at least incidental contact denotes compounds that are eligible for compliance with or equivalent to being in compliance with the Federal Food Drug and Cosmetic Act (Title 21 of the Code of Federal Regulations) standards for being generally recognized as safe (GRAS). The term “at least incidental contact” includes at least the unanticipated contact of food items being passed through the opening on which the closure strip is positioned as the food items are being inserted into the storage space. Although indirect contact between the caulking composition and the food items is preferred, in some embodiments the caulking composition may more directly contact the food, so long as the interaction between the food items and the caulking composition is in accordance with the regulations of the Federal Food Drug and Cosmetic Act.
It is noted that caulking compositions that are suitable for at least incidental food contact may be consistent with the classification of materials for “lubricants with incidental food contact” according to Title 21 of the United States Code of Federal Regulations § 178.3570 (revised as of Apr. 1, 2003), so long as the materials are consistent with the Federal Food Drug and Cosmetic Act and have an operable temperature range suitable for food storage and packaging. In some preferred embodiments, the operable temperature range of the storage device is defined as the temperature range that the storage bag is typically subjected to in shipping, packaging and food storage applications, for example, food storage applications ranging from approximately −10° F. to approximately 160° F. One example of a caulking composition that is listed as a “lubricant with incidental food contact” according to Title 21 Of the United States Code of Federal Regulations § 178.3570 and has an operable temperature range suitable for food storage and packaging comprises dimethylpolysiloxane. Another example is soy-based oils, for example, those distributed by Cargill Corp., and soy-based adhesives, for example, those distributed by DuPont as Pro-cote™ soy polymers.
In order to provide an air tight seal, in some embodiments the caulking composition 99 should be selected to have a work penetration of about 290 to about 340, in which the work penetration is measured at 60 strokes and a temperature of 77° F. in accordance with the National Lubricating Grease Institute (NLGI) system for rating greases by penetration and ASTM D217-97 titled “Standard Test Methods for Cone Penetration of Lubricating Grease” (1997). The NLGI classifies greases by consistency numbers as measured by worked penetration. In a preferred embodiment, the caulking composition 99 has a work penetration on the order of about 290 to about 340 and is classified as a grease having a NLGI consistency number equal to approximately 2. Although it is preferred that the caulking composition 99 have NLGI consistency number equal to approximately 2, greases having lower or higher NLGI consistency numbers may alternatively be utilized, so long as the caulking composition 99 may be applied to the interengaging profiles 21 of the resealable closure 20 using conventional injection methods and that the caulking composition 99 is contained within the resealable closure 20 when exposed to temperatures consistent with food storage container applications.
One example of a caulking composition 99, which meets the above requirements is silicone grease. Silicone grease is an amorphous, fumed silica thickened, polysiloxane-based compound. Silicone grease is formed by combining liquid silicone with an inert silica filler. One example of liquid silicone that may be utilized in forming silicone grease having suitable work penetration properties is polydimethylsiloxane having a specific gravity on the order of about 0.973 and a viscosity greater than about 300 centistokes, preferably on the order of about 350 centistokes. Fumed silica, an inert silica filler, has a chain-like particle morphology and when incorporated into liquid silicone forms three dimensional networks that trap the liquid and effectively increases the liquid's viscosity.
Silicone grease may provide desired work penetration values and temperature range to produce an adequately air tight seal between the interengaged profiles 21 of the resealable closure 20 by selecting the proper proportions of inert silica filler to liquid silicone. The proportion of inert silica filler to liquid silicone is generally selected to ensure that separation of liquid from solid in the silicone grease is substantially eliminated throughout the operable temperature range of the bag as applied to food container storage. In general, proportions of inert silica filler to liquid silicone are selected to yield a silicone grease viscosity that would not inhibit the application of the silicone grease onto the resealable closure 20. The proportion of inert silica filler to liquid silicone is preferably less than approximately 30% by weight. Even more preferably, the proportion of inert silica filler to liquid silicone is on the order of 6% by weight.
In one highly preferred embodiment, the silicone grease is provided by Clearco™ Silicone Grease (food grade) provided by Clearco Products Co., Inc., Bensalem Pa. Clearco™ Silicone Grease (food grade) has a work penetration value of about 290 to about 340, in which the work penetration is measured at 60 strokes and a temperature of 77° F. Clearco™ Silicone Grease (food grade) comprises 94% dimethylpolysiloxane and 6% fumed silica by weight % and has a specific gravity on the order of about 1.1. Clearco™ Silicone Grease may be utilized at temperatures ranging from approximately −40° F. to approximately 400° F. without chemical decomposition and is therefore well suited for food storage applications. In this embodiment of the present invention, the silicone grease 99 may be positioned along at least one of the male and female profiles 21 of the resealable closure 20, wherein incidental contact to food being inserted into the storage space of the storage device typically accounts for less that 5.0 ppb of silicone grease being incorporated into the food item being stored. In one embodiment, at least about 0.01 grams of caulking composition per linear foot of resealable closure is utilized, such as at least about 0.03 grams of caulking composition per linear foot of the resealable closure. Generally, not greater than about 0.07 grams of caulking composition is used per linear foot of the resealable closure.
In another embodiment of the present invention, the caulking composition 99 may comprise a soy adhesive. Similar to the above-described caulking compositions, the soy adhesive preferably is suitable for incidental food contact and has an operable temperature range suitable for food packaging and storage. One example of a soy adhesive is Pro-cote® soy polymer, which is available from DuPont™. In general, soy adhesive is prepared by extracting and refining soy oil from dehulled, flaked soybeans. The extracted material contains isolated soy protein in its native or globular form; and soluble, low molecular weight sugars. The extract is then processed in a controlled pH environment at tightly controlled temperatures to uncoil globular native soy protein into smaller units, and fractionating the material into uniform polymer fractions. The isolated protein molecule fractions are highly reactive and are chemically treated to modify the protein chain to provide desired adhesive properties. Unmodified soy-based oils may also be employed as a caulking composition. An alternative source of soy based oils and adhesives is the soy products available from Cargill™ Industrial Oils & Lubricants.
As will be appreciated, numerous reactive materials may also be employed as caulking compositions. In particular, materials which may be coated as separate reactants onto separate interengaging portions of the closure which are admixed upon engagement of the interengaging portions of the closure may be utilized. Accordingly, when the closure parts are engaged the admixed reactants will be combined, reacting and forming in-situ a caulking composition which is infiltrated into a least one void defined by the engaged interengaging portions of the closure. One example of such a system comprises a free-flowing reactive polymer liquid and a liquid cross-linking agent, each coated on separate portions of the closure. In this example, when the closure is engaged, the separate portions contact, admixing the polymer and cross-linking agent, providing a viscous, cross-linked polymer caulking composition which is infiltrated into voids in the closure defined by the interengaged portions of the closure. Other examples include the provision of a free-flowing liquid and a gelling agent on separate portions of the closure to form a viscous caulking agent upon admixture, and the provision of a two-part adhesive material which react to form an adhesive upon admixture, for example, formation of a pressure-sensitive adhesive. Other types of chemical transformations will also be apparent to those of skill in the art.
Referring now to
The void space defined by stem 43, post 38 and asymmetrical head 36 comprises a groove configured to selectively engage the asymmetrical head 32 of the corresponding interengaging profile 23, 24. Stem 43, post 38 and asymmetrical head 36 are spaced to selectively engage corresponding interengaging profiles 23, 24. The spacing between the post 38 and stem 43, and between post 38 and asymmetrical head 36 is sufficiently narrow to bias asymmetrical head 32 toward asymmetrical head 36 when profiles 23, 24, 26, and 28 are engaged. The biased positioning of the asymmetrical head 36 in combination with the spacing of post 38 to correspond to the width of asymmetrical heads 23, 24 defining a grove that reversibly interlocks asymmetrical head 23, 24 into the groove when the profiles are engaged.
Still referring to
In another embodiment, shown in
In another embodiment, shown in
Referring now to
Additionally, although not depicted in
Referring to
Referring back to
Referring to
The vacuum valve 30 can be any suitable valve, including those known as “Goglio” type or “Raackmann” type. Goglio-type valves are available, for example, from Bosch, Wipf, and Wico; Raackmann-type valves are available, for example, from Amcor. Other examples of suitable vacuum valves 30 include those described in U.S. Pat. Nos. 6,913,803; 6,733,803; 6,607,764; and 6,539,691, each of which is incorporated herein by reference in its entirety. In one embodiment of the present invention, the vacuum valve assembly may be consistent with the valves disclosed in U.S. patent application Ser. No. 11/100,301, entitled “EVACUATABLE CONTAINER”, filed Apr. 6, 2005. It is noted that the sealing nature of the valve element 35 may be enhanced by incorporating a sealing material and/or a caulking composition into the sealing members of the valve assembly. In another embodiment, the vacuum valve assembly 30 may further include at least one rib (not depicted) extending from the interior side of the valve assembly base 31, wherein the rib extending from the base 31 ensures that the valve assembly is not obstructed during application of the vacuum.
As shown in
The honeycomb pattern of channels is depicted in isometric view in
Regardless of the geometry selected for providing the channels, the stand-off structure 70 produces a passage for the removal of liquids and gases by providing a cross-section with a series of raised surfaces and recessed surfaces. In one embodiment, the standoff structure is integral with a fluid conduit providing fluid communication between the interior of the storage device and a vacuum system by which the storage device is evacuated, and which comprises a vacuum valve, the standoff structure, optionally a quick-connect device, optionally a liquid/vapor separator and the suction side of a vacuum pump. Referring to
As shown in
As shown in
In one application, a vacuum pump is attached to the vacuum conduit which includes at least one vacuum valve and in fluid communication therewith, at least one standoff structure. The vacuum pump is operated, applying a vacuum to the interior of the storage device through the vacuum valve assembly 30 and standoff assembly causing the storage space 22 to collapse upon a food article contained therein. During the application of the vacuum, the stand-off structure 70 separates the food article from the vacuum valve assembly 30, ensuring that the food article does not obstruct the flow of air or liquids to be removed from the storage space 22, and insuring that the walls of the storage device conform tightly to the food article. Additionally, as the vacuum causes the portion of the plastic sheet 16 opposing the stand off structure 70 to collapse upon the raised portions of the stand-off structure 70, any remaining liquid and air may be removed via the stand-off structure's 70 recessed channels. During the application of the vacuum, the distance D1 separating the vacuum valve assembly 30 from the opposing raised surfaces of the stand-off structure 70 may be substantially eliminated while maintaining an effective passageway for removing the remaining air and liquids from the storage device through the stand-off structure's 70 recessed channels.
The evacuable package 14 may be produced via any suitable processes. For example, the evacuable package may be made by a horizontal process (e.g., where the flexible material 12 forming side panels 17, 19, and resealable closure 20 move in a generally horizontal direction), a vertical process (e.g., where the flexible material 12 forming side panels 17, 19, and resealable closure 20 move in a generally vertical direction), and combinations thereof.
In one general embodiment of a horizontal process, two extended lengths of the flexible material 12, each forming a side panel 17, 19 move in a generally horizontal direction. An extended length of resealable closure 20 may be attached to side panels 17, 19 or may already be integral with the flexible material 12. A stand-off structure 70 can be attached to one or more of the side panels 17, 19, or can be integral with side panels 17, 19, or can be side panels 17, 19. A vacuum valve 30, and an optional corresponding hole, are typically installed into/produced in one of the extended lengths of flexible material 12 at predetermined intervals, to correspond to one vacuum valve 30 per evacuable package 14. After the various elements have been joined to form an extended length, seals, which will result in lateral sides 15 and bottom edge 13 may be made. Lateral seal portions (not illustrated) which are seals located proximal the overlap of the lateral sides 15 and the resealable closure 20, are usually made (e.g., crushed) simultaneously with the lateral sides 15 seals, but could be made in a separate step.
In alternate embodiment of a horizontal process, one extended length of flexible material 12 moves in a generally horizontal direction. This flexible material is folded to form both side panels 17, 19 and bottom edge 13. Any order of applying resealable closure, stand-off structure 70 and vacuum valve 30 can be used. Similar to the above embodiment, after the various elements have been joined to form an extended length, the lateral sides 15 and lateral seal portions may be made.
In one embodiment of a vertical process, two extended lengths of the flexible material 12, each forming a side panel 17, 19 move in a generally vertical downward direction. Similar to above, an extended length of resealable closure 20 may be attached to the side panels 17, 19, before, after, or concurrently with the bottom 13 being sealed, or the resealable closure 20 may already be integral with the flexible material 12. A stand-off structure 70 can be attached to one or more of the side panels 17, 19, or can be side panels 17, 19. A vacuum valve 30, and an option corresponding hole, are typically installed into/produced in one of the extended lengths of flexible material 12 at predetermined intervals, to correspond to one vacuum valve 30 per evacuable package 14. After the various elements have been joined to form an extended length, seals, which will result in lateral sides 15 may be made. Lateral seal portions (not illustrated) which are seals located proximal the overlap of the lateral sides 15 and the resealable closure 20, are usually made (e.g., crushed) simultaneously with the lateral sides 15 seals, but could be made in a separate step.
In alternate embodiment of a vertical process, one extended length of flexible material 12 moves in a generally vertical direction. This flexible material is folded to form both side panels 17, 19 and bottom edge 13. Any order of applying resealable closure, stand-off structure 70 and vacuum valve 30 can be used. Similar to the above embodiment, after the various elements have been joined to form an extended length, the lateral sides 15 and lateral seal portions ma y be made.
It will be appreciated that the resealable closure structure 20, shown in
As mentioned above, in one embodiment the reclosable storage device comprises a portion of a system which includes a vacuum device having a low pressure side attached to a vacuum conduit which is in fluid communication with the interior of the storage device and which conduit includes a vacuum valve (described above). Optionally, the assembly includes also a quick-disconnect means in the vacuum conduit between the vacuum pump and the storage device and optionally includes a gas/liquid separator means in the vacuum conduit between the suction side of the vacuum pump and the storage device.
As will be appreciated, any number of vacuum devices can be utilized to evacuate a reclosable storage device in accordance with the present invention, however, in some embodiments, it is preferred to employ a hand-held or portable vacuum pump. An example of one suitable portable device is illustrated in
As shown in
In operation, the portable vacuum pump 40 is structured to engage the vacuum conduit connected to the interior of the storage device, for example, as illustrated, the outer surface of the vacuum valve assembly 30. When the portable vacuum pump 40 is engaged and actuated the vacuum valve assembly 30 is actuated by the resultant pressure differential, the valve element 35 moves into the first position (described above) and the vacuum conduit passage is open and fluid (gas and liquid) is withdrawn from the bag 14 through the vacuum conduit into the suction side of the vacuum pump. The fluid may be both liquid and gas. When a separator assembly is present in the vacuum conduit, liquid and gas are drawn into the liquid separator assembly 90, the liquid contacts the diverter 96 and is deposited in the accumulator housing 94. Thus, the liquid is not drawn with the gas towards the vacuum pump. The gas is exhausted via the vacuum pump from the vacuum pump assembly 40. When the accumulator housing 94 needs to be emptied, a user may simply remove the tube 92 and base 98 allowing the liquid to drain from the vacuum pump assembly 40.
When a portable vacuum pump 40 is actuated, air is withdrawn from the storage space 22. Thus, as shown in
To further assist in facilitating the removal of fluids from the evacuable package 14 to form a vacuum, it may be useful to restrict flow of solids and/or liquids proximal the valve 30. Thus, in one embodiment, one or more barriers may be utilized proximal at least a portion of the vacuum valve 30. These barriers may be a part of the stand-off structure 70, or may be separate from the stand-off structure 70. One embodiment of a useful barrier arrangement is illustrated in
The plurality of barriers 76 may be formed by any suitable methods. For example, at least a portion of the first side panel 17 of the evacuable package 14 may be bonded to a portion of the second side panel 19 of the evacuable package 14 (e.g., via heat sealing and/or an adhesive), thereby creating one or more barriers 76 integral with both these first and second side panels 17, 19. Thus, the barriers 76 may comprise an uninterrupted span from the first side panel 17 to the second side panel 19 of the evacuable package 14. In one embodiment, the barriers 76 consist essentially of portions of the first and second side panels 17, 19 of the evacuable package 14. In another embodiment, a polymeric material may be bonded to each of the first and second side panels 17, 19 of the evacuable package 14 to provide the barriers 76. In the illustrated embodiment, the plurality of barriers 76 are intermittently spaced about at least a portion of the vacuum valve 30. Thus, the plurality of barriers 76 at least assist in defining a portion of one or more of the channels 77.
The barriers 76 may be spaced about the valve 30 in any suitable arrangement. By way of example, the barriers 76 may define at least a portion of an ellipse, as illustrated in
In a related embodiment, a separate visual indicator may be utilized on the exterior of the evacuable package 14. This visual indicator may correspond with the orientation of the sealing line. Thus, the fill level of the evacuable package 14 may be further emphasized. In one embodiment, the visual indicator is a color indication and/or a textural indication. This visual indicator may also be utilized without the use of barriers 76, thereby providing an external visual indicator to a user of the fill level of the evacuable package.
As illustrated in
The plurality of barriers 76 may be located in any suitable location within the evacuable package 14. As described above, the plurality of barriers 76 may be located proximal the periphery of the vacuum valve 30. In another embodiment, and with reference to
As may be appreciated, a resealable closure 20 may also be utilized in accordance with any of the above referenced barrier embodiments. For example, and with continued reference to
As noted above, a stand-off structure 70 may be utilized within the evacuable package 14 to facilitate fluid communication between the interior of the evacuable package 14 and the vacuum valve 30. As may be appreciated, extra materials and/or handling time may be required to interconnect the stand-off structure 70 to the interior of the evacuable package 14. Thus, in one embodiment of the present invention, a resealable closure comprising a stand-off structure may be used. One embodiment of such a resealable closure is illustrated in
Referring now to
The second flange 52′ may include a vacuum valve 30 interconnected therewith. In this regard, any of the vacuum valve assemblies described above may be utilized in conjunction with the skirt portion 52b of the second flange 52′. For example, a hole may be punched in the skirt portion 52b followed by interconnection of a vacuum valve 30 to the skirt portion 52b relative to the punched hole. In another embodiment, and as described in further detail below, the vacuum valve 30 may be integral with the skirt flange portion 52b, where the vacuum valve 30 is formed via ultrasonic welding and/or thermal heating techniques.
The top portion 52a and skirt portion 52b of the resealable closure 230 may comprise any suitable material. For example, the top portion 52a may comprise a first polymeric material (e.g., low-density polyethylene (LDPE) or linear-low density polyethylene (LLDPE)) having a melting point of about at least about 350° F., such as at least about 370° F. The skirt portion 52b may comprise this same first polymeric material, or the skirt portion 52b may comprise a second polymeric material. For example, it may be desirable to facilitate bonding of a vacuum valve 30 to the skirt portion 52b without substantial degradation of the skirt portion. Thus, in one embodiment, the skirt portion 52b may comprise a polymeric material having a melting point of at least about 275° F., such as at least about 350° F., or at least about 400° F., or even at least about 420° F. to facilitate ultrasonic welding of and/or thermal bonding of the vacuum valve 30 to the skirt portion 52b. One useful material in this regard is medium density polyethylene (MDPE).
In a related approach, the top portion 52a may have an average thickness, excluding the interengaging profiles 21, such as at least about 3 mils. The skirt portion 52b may have an average thickness, such as at least about 10 mils, 20 mils or even at least about 30 mils. In the latter regard, bonding of the vacuum valve 30 to the skirt portion 52b may be facilitated due to the increased thickness of the skirt portion 52b. In one approach, the ratio of the thickness of the skirt portion 52b to the thickness of the top portion 52a is at least about 1.5:1, such as at least about 3:1, at least about 5:1, or even at least about 10:1.
The first flange 50 and second flange 52′ of the resealable closure 230 may be produced by any known or developed techniques. One embodiment for creating a resealable closure 230 comprising a stand-off structure 70 is illustrated in
The embossing may be accomplished while the resealable closure 230 is in a cold form, such as prior to the resealable closure 230 being interconnected with the flexible material 12, which results in construction of the evacuable package 14. Alternatively, the skirt portion 52b may be embossed while the resealable closure 230 is being manufactured. In this regard, the resealable closure 230 could then be immediately fed to an apparatus for interconnection of the resealable closure 230 to the flexible material 12, thereby facilitating increased manufacturing efficiency.
As noted above, a vacuum valve 30 may be utilized in conjunction with the resealable closure 230 and stand-off structure 70. In one approach, a vacuum valve assembly 30 may be interconnected to the resealable closure 230, such as via thermal welding, chemical bonding, or adhesives. In this regard, a hole may be punched through a portion of the resealable closure 230, after which a vacuum valve 30 may be positioned relative to the hole and bonded thereafter to the resealable closure 230.
In another embodiment, a vacuum valve may be formed integral with the resealable closure 230. One system for forming such a vacuum valve is illustrated in
As may be appreciated, various types of food products may be utilized in accordance with the present invention. For example, raw meats may often be utilized within the evacuable package 14. Such meats may include various liquids, such as blood, which, while non-frozen, may appear normal to a user. However, upon removal of fluids from the evacuable package 14, such as via the vacuum pump 40 described above, followed by freezing of the meat, portions of liquids within the evacuable package 14 may streak and/or otherwise provide a undesirable visual appearance to a user. Thus, in one embodiment of the present invention, a wicking material may be utilized in conjunction with the evacuable package 14 to facilitate wicking of liquids away from food products, thereby restricting possible undesired visual effects. One embodiment of such an evacuable package 14 is illustrated in
In another embodiment, the wicking material 93 is utilized within the storage space 22 of the evacuable package 14 without the use of barriers 76. In this embodiment, an adhesive or other suitable type of bonding material may be utilized to adhere the wicking material 93 to one or more of the side panels 17, 19 of the evacuable bag, thereby restricting movement of the wicking material 93 within the evacuable package 14.
The wicking material 93 may be may be any material adapted to wick, adsorb or absorb liquids. For example, the wicking material 93 may be a cellulose-based material, such as paper, or a synthetic absorbent (e.g., a sponge), a desiccant material, or any other material adapted to wick, adsorb or absorb liquids. The wicking material 93 may be associated with the evacuable package 14 at any suitable time. In one approach, the wicking material 93 is applied to at least one side of the flexible material 12 during the production of the evacuable bag 14. For example, a label-type applicator may be utilized to apply a paper-type wicking material to the flexible material 12 at any suitable time during a horizontal or vertical bag manufacturing process, as described above.
While illustrative embodiments of the invention are disclosed herein, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments that come within the spirit and scope of the present invention.
This application is a continuation-in-part of U.S. patent application Ser. No. 11/186,131 filed Jul. 20, 2005, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Nos., 60/590,858, filed on Jul. 23, 2004, 60/602,685 filed on Aug. 19, 2004, and 60/609,920, filed on Sep. 15, 2004. Each of the above patent applications is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60590858 | Jul 2004 | US | |
| 60602685 | Aug 2004 | US | |
| 60609920 | Sep 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11186131 | Jul 2005 | US |
| Child | 11627893 | Jan 2007 | US |
