This invention relates generally to insulated laminates, and more specifically relates to insulated laminate products and methods for making a multilayer laminate that may be formed into containers or other products, such as double layer bags and multi-layer pads having insulating material disposed between the layers.
Paper bags are frequently used to carry cold groceries because they have better insulating properties than the thin, plastic bags used most commonly in retail sales. Some stores use double ply paper bags for bagging frozen foods to further increase the amount of insulation. Multi-wall paper bags for holding bulk products such as pet food, fertilizer, or charcoal are also known. In some double ply bags, an adhesive is used between the paper layers to bond the layers together to give the bag additional strength and resistance against tearing. In these bags, the adhesive is flooded onto the paper substrates so they are fully covered with adhesive. Insulated plastic bags are also sometimes used to transport cold or frozen foods. Typically, insulated plastic bags are relatively expensive and are not biodegradable or readily recyclable, which makes them less suited for single use applications.
As grocery delivery is growing more popular, problems are being found with existing packaging used for transporting groceries, and particularly cold items. Insulated boxes are bulky and expensive. They take up a relatively large amount of space to ship and store before being used to hold/deliver groceries, and they take up a large amount of space in the garbage or recycling of the end recipient. Existing paper bags do not provide sufficient insulation to keep frozen or cold groceries at or below threshold temperatures for the extended length of deliveries or when the groceries are left at the door of a recipient for extended periods of time.
Containers made with paperboard having thermally activated expandable insulating material disposed between the layers of paperboard are known, such as disclosed in U.S. Pat. No. 9,056,712, which is incorporated by reference in its entirety herein. However, these prior containers are rigid containers, such as cups or clamshells.
In one embodiment according to the present invention, a flexible insulated laminate includes first and second flexible ply portions each having inner facing surfaces that are bonded together with an adhesive along at least one edge of the first and second ply portions. An expanded insulating material including expanded microspheres is disposed on at least one of the inner facing surfaces of the first and second ply portions to space the ply portions apart and form at least one air void between the ply portions. The expanded insulating material is spaced inwardly from the at least one edge of the bonded first and second ply portions and the adhesive extends about the insulating material to keep the expanded insulating material from passing beyond the at least one edge of the bonded first and second ply portions. In some forms the adhesive forms a continuous perimeter around the expanded insulating material to seal the expanded insulating material within the at least one edge of the bonded first and second ply portions.
In some forms, the ply portions are two separate plies of material. In alternative forms, the ply portions are of a single ply of material folded over upon itself with the ply portions extending from a common fold line.
In some embodiments, the ply portions are of a paper material. An outer surface of one of the first and second ply portions may be coated with a water-resistant coating. For example, the ply portion may have an outer surface with the water-resistant coating having a Cobb value of less than 25 g/m̂2.
The flexible laminate can be formed into a variety of products. In one embodiment, the bonded first and second ply portions with the expanded insulating material and adhesive therebetween are formed into a collapsible bag with a base and opposing side and end walls extending from the base. The opposing side and end walls form a bag opening at uppermost edges of each of the side and end walls opposite from the base. An exterior surface of the bag is formed by one of the first and second ply portions, and interior surface of the bag is formed by the other of the first and second ply portions. In some forms of the bag, the opposing side and end walls are separated by preformed fold lines that extend from the base.
The opposing side and end walls each have a length measured from the base to the uppermost edge thereof. In some forms, each of the opposing side and end walls include an upper portion extending from the uppermost edge toward the bag base free from expanded insulating material. The length of the upper portion free from expanded insulating material can be preferably at least one eighth of the length of the respective opposing side or end wall.
In some forms of the bag, the adhesive extends between the first and second ply portions along the uppermost edges of each of the side and end walls in a non-continuous manner. Alternatively, the adhesive forms a continuous perimeter around the expanded insulating material to seal the expanded insulating material within the at least one edge of the bonded first and second ply portions.
The insulating material is applied so as to be spaced from each of the fold lines introduced to the flexible laminate such that the insulating material is not crushed or otherwise inhibited from expanding when the insulating material is heated during manufacture of the laminate.
In some embodiments, the flexible laminate has expanded insulating material configured to provide the flexible laminate with an R-value between 0.05 m̂2 K/W to 0.5 m̂2 K/W.
In some forms, the first and second ply portions with the expanded insulating material and adhesive therebetween are formed into an envelope.
In various embodiments, the expanded insulating material is arranged in a pattern of individual spaced apart portions that are aligned in a plurality of columns. In some forms, the expanded insulating material has a thickness between 0.1 and 0.5 inches.
Exemplary methods of making a flexible, insulating laminate are also described herein. A method of making a flexible insulating laminate includes applying an insulating material in an unexpanded form in a pattern to a first side of a first substrate portion, applying an adhesive material different from the unexpanded insulating material to the first side of the first substrate portion so that the adhesive material surrounds and is spaced from the unexpanded insulating material, and bonding a second substrate portion to the first side of the first substrate portion via the adhesive material to form an unexpanded laminate having the unexpanded insulating material disposed between the first and second substrate portions with the adhesive material surrounding and spaced from the unexpanded insulating material, and heating the unexpanded laminate to cause the unexpanded insulating material to expand to provide at least one air void between the bonded first and second substrates to form the flexible insulating laminate.
Some methods further include forming the unexpanded laminate into a collapsible bag. In some methods, the step of heating the unexpanded laminate occurs after forming the unexpanded laminate into a collapsible bag. In some forms, forming the unexpanded laminate into a collapsible bag includes forming fold lines in the unexpanded laminate for collapsing and expanding the bag in locations that are spaced from the unexpanded insulating material.
In some forms, the unexpanded laminate is heated using an industrial microwave. In some examples, the unexpanded insulating material is heated to a temperature of between 200 and 250 degrees Fahrenheit to cause expansion of the insulating material.
In some methods, the unexpanded insulating material includes unexpanded microspheres prior to heating of the insulating material, and after heating of the insulating material within a predetermined activation temperature range, the expanded insulating material comprises unruptured expanded microspheres.
In some forms, the unexpanded insulating material has a viscosity of between 3,000 and 4,500 centipoise at 72 degrees Fahrenheit. Alternatively or additionally, the unexpanded insulating material has a thickness ranging between 2 and 30 mil prior to being expanded by heating.
The insulating material is applied to the first substrate while the first substrate is advancing at a predetermined speed. In some forms, the unexpanded insulating material is applied to the first substrate while the first substrate is advanced at a speed greater than 100 ft/min. Some methods further include measuring the speed at which the first substrate is advanced, and applying the unexpanded insulating material in the pattern repeatedly at predetermined spaced apart locations on the first substrate based on the measured speed of the first substrate.
Some methods further include heating the unexpanded laminate to remove moisture from the unexpanded insulating material and allowing the dried insulating material to cool prior to heating the unexpanded laminate to cause the unexpanded insulating material to expand.
In some forms, the adhesive material is applied to form a continuous perimeter about the unexpanded insulating material to seal the unexpanded insulating material between the bonded first and second substrate portions.
Some methods further include forming fold lines in the bonded first and second substrate portions at predetermined locations spaced from the insulating material.
Systems used for making the flexible insulated laminates are also described herein. An inline system for making a flexible insulated laminate includes a roll for feeding a web of a first substrate to be processed, a roll for feeding a web of a second substrate to be processed, an insulating material applicator to apply a heat expandable insulating material to the first substrate web at predetermined insulating material locations on the first substrate web while the first substrate web is advanced in a machine direction, an adhesive applicator to apply an adhesive material to the first substrate web at predetermined adhesive locations on the first substrate web spaced from the applied expandable insulating material while the first substrate web is advanced in the machine direction, a pair of nip rolls to bond the second substrate web to the first substrate web at the predetermined adhesive locations while the substrate webs are advanced in the machine direction, a bag converter to convert the bonded first and second substrates into a collapsible bag while the bonded substrates are advanced in the machine direction, and a heater to heat the expandable insulating material disposed between the first and second substrates to cause the insulating material to expand while the bonded substrates are advanced in the machine direction.
In some systems, the insulating material applicator is a nozzle applicator having a plurality of nozzles for applying heat expandable insulating material arranged in a plurality of columns to the first substrate web. Some systems further include a flowmeter for measuring the amount of heat expandable insulating material applied to first substrate by the nozzle applicator.
Some systems further include a vision system having an optical detector for confirming the applied heat expandable insulating material is located at the predetermined insulating material locations on the first substrate.
Other features and advantages will be apparent from the following description of various embodiments, which illustrate, by way of example, the principles of the disclosed insulated laminates and systems and methods for making the same.
Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale or to include all features, options or attachments. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.
A flexible, insulated laminate includes one or more flexible substrates of various materials, such as but not limited to kraft paper, plastic, metallized paper, metallized plastic films, upon which an expandable insulating material is disposed. In some forms, the expandable insulating material is applied to a first flexible substrate. Depending upon the composition of the expandable material, it is either dried for later expansion (activation), is partially expanded, or is fully expanded before further processing of the laminate into a final product. In some forms, the expandable insulating material is applied in a predetermined pattern, such as in an array of spaced-apart areas of insulating material or in other forms, it may be applied in a random and arbitrary pattern. A laminating adhesive may be applied in a manner to surround the expandable insulating material for bonding a second flexible substrate to the first flexible substrate. The laminating adhesive is of a different material composition from that of the expandable insulating material and performs the function of bonding the substrates together securely. In an industrial process for making the laminate, a web of one of the substrates is conveyed in a longitudinal machine direction and the laminating adhesive is applied along both of the lateral edges of the substrate that extend in the longitudinal machine direction. Laminating adhesive is also applied to the substrate at predetermined and successively longitudinally-spaced locations so that the applied adhesive extends transversely to the machine direction. Accordingly, the laminating adhesive effectively extends around the entire perimeter of the applied insulating material in order to completely seal in the insulating material once a second flexible substrate is bonded to the first substrate. When the substrates are bonded to each other at the respective lateral edges and at the predetermined transverse locations between the lateral edges, the first and second substrates will be in registration, i.e., with the lateral edges of one substrate aligned with the corresponding lateral edges of the other substrate such that there are no offset portions of one substrate from the other substrate adhered thereto. Alternatively, the lateral edges of the substrates may be offset from one another assuming the insulating material and the laminating adhesive are in registration with one another. After bonding of the substrates, the expandable insulating material is disposed and sealed therebetween, thereby forming a sealed, flexible and insulated laminate. Completely sealing in the insulating material is preferred to reduce the likelihood of the expanded insulating material from escaping from the formed laminate.
In some forms, the expandable insulating material may be dried, such as by application of heat, prior to being expanded. For example, the dried but not expanded thermally expandable insulating material can be further heated and hence activated or expanded just after the sealed laminate is formed. Alternatively, the expandable insulating material can be further heated and activated or expanded after the laminate is later formed into a partially finished or completely finished product. When the expandable insulating material is applied in non-continuous layer, such as a pattern or array of spaced areas that each have a predetermined shape, the insulating material, when expanded, acts as an array of spacers that create spaces between the first and second substrates. Air gaps are formed in the space between the spaced apart first and second substrates where the substrates are not adhered to each other and where the insulating material is not present. The composition of the insulating material, when fully activated or expanded, creates relatively large air gaps which provide significant insulating qualities to the laminate and further contributes to the flexibility thereof so as to provide a cushioned, flexible, laminated structure with a scalable thermal insulation level depending on the thickness of the expanded insulating material in the finished products. It was discovered that a relatively small amount of expandable insulating material could provide the laminate with good insulating qualities. When made with paper substrates, such a laminate is also environmentally friendly in that it is repulpable and recyclable.
The flexible, insulated laminate can be constructed into various forms including containers, such as grocery bags or insulating packaging, mailers, inserts, or pads. For example, an insulated pad formed from the insulated laminate could be used within a hot food container such as a pizza box. Products formed with the insulated laminate include one or more adhesive-sealed cushioned panels having expanded insulating material that form air gaps to provide additional insulating properties. The sealed panels are particularly suited for use with food products, as the insulating material is kept separate from and out of contact with the food products via the sealing provided by the laminating adhesive. Items made of a flexible, insulated laminate can be collapsed or flattened and compressed for shipping and storage, and can be bent, folded, and/or rolled in use without being damaged. When the insulated laminate is formed into flexible containers such as bags, the containers advantageously may be of variable size, for example by rolling up the top part of an open bag such that the interior volume of the bag closely matches the volume of the contents held within the bag, thereby increasing the insulative effectiveness of the bag. In this regard, the bag can be free of the insulating material at and near the top of the bag since this part of the bag is to be folded over.
In one form, an insulated bag is constructed of a flexible paper laminate containing an expandable insulating material between the paper layers. The insulating material is fixed to either the outer surface of the inner paper layer or the inside surface of the outer layer. In general, the insulating material is fixed to only one of the substrates, and the opposing substrate will only engage the insulating material and will not be fixed to it because the insulating material applied to one of the substrates is dried or expanded prior to bonding the opposing substrate to the one substrate. However, in an alternative form, the insulating material could be bonded to both substrates. A continuously formed laminate can be die-cut to form a bag blank that will be later processed within a bag making machine, or the lamination can be directly fed into the bag making machine. Alternatively, the lamination of the substrates can be accomplished by the bag machine itself. In each case, the bag making machine will fold and glue the laminate into the final shape of a bag. The insulated bag described herein has an open top and is made of a flexible material and includes a flexible insulating material so that the bag can be folded and used without damaging the insulating material layer.
In another form, a flexible insulating laminate can be die cut into an insulated pad that can be placed within a food container to provide improved heat retention of the food product by reducing the amount of heat being lost by the food product through the container walls. For example, the insulating laminate pad may be cut into a circle, square, or any other shape that roughly conforms to the size and shape of the interior of a container. In one application, the pad may be used in conjunction with a typical pizza box container. The pad would be placed inside the pizza box on the base thereof, and would support the underside of a pizza. In this application, the insulated pad was found to be very effective in slowing the rate at which the pizza cools by keeping heat emitted from the pizza from rapidly transferring to and out of the bottom wall of the box and to the exterior environment. If desired, another insulated pad can be attached to a top interior of the pizza box to further reduce heat losses through the top wall. The insulated pad may be formed with one or more substrates having non-flat surface features, such as embossed or fluted air flow channels, and may be particularly adapted to absorb steam or moisture.
One method of manufacturing a flexible insulated laminate is now described. Other alternative methods will be described later. The first substrate 102 in web form is unwound from its roll 105 as shown in
As shown in
The expandable insulating material 110 contains a binder agent, heat expandable microspheres, and other common additives used in formulating an aqueous coating, such as rheological modifiers, defoamers, and so on.
The binder solution in which the microspheres are embedded may include rheology modifiers, resins, plasticizers, thickeners, surfactants, and solvents. The applicator can apply the insulating material 110 at varying wet thicknesses depending on the desired insulative properties (i.e. R-value) of the insulated laminate. The insulating material 110 should be fluid enough to be applied by the applicator 106 but viscous enough to maintain the insulating material in the areas of the pattern in which it is applied so it does not flow out of these areas after application of the insulating material. In one form, the wet insulating material 110 is applied in a 2 mil-30 mil thick layer. In a more preferred form, the wet insulating material 110 is applied in a layer that is between 3 mil-10 mil thick. After full expansion of the microspheres, the insulating material 110 will be between 0.1 inches to 0.5 inches thick. In a preferred embodiment, the insulating material 110 is 0.15 inches to 0.3 inches thick after expansion. As mentioned earlier, the insulating material may be used primarily as a spacer to keep the substrates apart such that one or more insulative spaces or air gaps 909, is formed and maintained between the substrates (see
The insulating material 110 can be applied in a variety of patterns to one of the substrates. Preferably, the insulating material 110 is applied so it is spaced from all locations where the substrate laminating adhesive will be applied and from locations where fold lines will be located. For example,
In
As shown in
In one form, the insulating material 110 at its closest point, e.g., the edge of the closest rectangular area or areas of insulating material 111, is spaced apart from the fold lines 502, 503, 504, 505, 587, 597 by 0.5 inches-1 inch. In a preferred form, the insulating material 110 at its closest point is spaced apart from the fold lines by 11/16 of an inch. Additionally, the insulating material 110 may be spaced apart from the top of the blank 500. In use, the top portion 611 of the bag 600 shown in
The insulating material 110 may be applied to the first substrate 102 in a variety of patterns. In one form, the insulating material 110 is applied in an array of rectangular areas 111 of substantially equal size as shown in
The spacing between the rectangular areas 111 of insulating material 110 can vary as well such that they are either more tightly or loosely spaced from the spacing that is shown in the figures.
Continuing with the description of the process shown in
In a preferred form, the temperature of the heater 112 and speed of the conveyed substrate 102 is set so that the applied heat does not activate the microspheres 1000 in the insulating material 110, or at least does not fully activate the microspheres. Instead the drying creates a “dormant” insulating material 110 comprising unexpanded microspheres or partially expanded microspheres embedded in a dry binder. This dormant insulating material 110 can be fully activated at a later time in a “post-activation” process by applying additional heat after the insulated laminate 205 is formed. By pre-drying the insulating material 110, the first substrate 102 upon which the insulating material 110 is bonded may be easily and more compactly rolled up for later processing, and the second substrate 202 may be laminated to the first substrate 102, without disrupting the applied pattern of the still wet insulating material 110 on the first substrate 102. In a preferred embodiment, the insulating material 110 is dried out without activating any of the microspheres 1000. However, if higher temperatures are used in the heater 112 in order to reduce the amount of time required to dry out the insulating material 110, this higher temperature can cause some partial activation of the microspheres 1000. Full activation of the microspheres may be avoided by keeping the average temperature of the insulating material 110 under 225 degrees Fahrenheit. The activation temperature of the microspheres 1000 can be altered by changing the encapsulated liquid and or the wall thickness of the microspheres. In order to allow for later activation of the microspheres 1000, the insulating material 110 is preferably formulated to remain elastic once dried to allow the microspheres to expand. If the insulating material 110 is not sufficiently elastic when dried, the microspheres embedded in the insulating material 110 will not be able to overcome the rigidity of the surrounding solid components of the insulating material (such as the binder) and as a result the microspheres will not be allowed to expand.
After passing through the heater 112 shown in
After the initial heating process, the first substrate 102 may be rolled up, preferably with a protective layer for being stored and/or transported to another line for lamination of a second substrate and subsequent processing. Alternatively, this step could be skipped and the lamination of the second substrate 202 could be done immediately after the process of drying or activating the insulating material, such as shown in the alternative processes shown in
If the first substrate 102 is not being laminated to the second substrate immediately after the insulating material 110 is applied and dried or activated, a slip film 116 may be applied, but not bonded, to the first substrate 102 on the side 101 having the insulating material 110. The insulating material 110 is sandwiched between the first substrate 102 and the slip film 116. The slip film 116 serves to protect the insulating material 110 during rewinding of the first substrate 102 onto a roll 118 and keeps the insulating material 110 from sticking to the opposite surface 103 of the first substrate 102 as the first substrate 102 is rolled up. The slip film 116 is made of a material to which the insulating material 110 will not stick. In a preferred embodiment, the slip film 116 is a plastic film, such as a polyester film. The first substrate 102 and slip film 116 are rewound to form a roll 118. The dormant insulating material 110 is compressible and due to the elastic qualities of the dried binder will largely return to its original thickness, or nearly to its original thickness once the first substrate 102 is later unwound again for further processing. The thickness of the dormant insulating material 110 will be similar to, or slightly greater than the thickness of the applied insulating material before it is dried, depending on the degree of expansion of the insulating material during the drying process. The roll 118 of first substrate 102 with dormant expandable insulating material 110 can be stored for extended periods of time before being used to make finished products, such as insulated bags 600 or insulated inserts 700. When the first substrate 102 is used to make a bag 600 with a bag making machine line 300 or an insert 700 with an insert making machine line 350, it must first be formed into a laminate 205 with a laminate making machine line 200. The first substrate 102 is unwound and the slip film 116 is removed as shown in
After passing through the heater 112 shown in
In the process for making a flexible insulated laminate 205 using the first substrate 102 having the insulating material 110 bonded to a first surface 101 thereof, a second substrate 202 in web form is unwound from roll 217 and fed into the laminate making machine 200, as shown in
The laminating adhesive 207 may be applied within some of the regions not covered with insulating material 110, depending upon the end-use of the laminate 205. As shown in
In a preferred embodiment, the laminating adhesive applicator 206 applies adhesive 207 around the insulating material 110 and following the peripheral edges of one of the substrates 102, 202 that form the blank 500/800. For example, as shown in
As shown in
In a preferred embodiment, the insulating material 110 applying machine line 100 and the laminate making machine line 200 are combined into a single line or system as shown in
The process of
In each of the processes described, the laminate 205 can be rolled or cut into sheets in order to be stored and/or transported to another machine line in order to be formed into final products, such as the bag 600 or the insert 700. Alternatively, the laminate 205 can be conveyed directly into a machine line for producing a final product so that there is a single, continuous process for forming the laminate 205 and a product therefrom.
To form a bag 600, the laminate 205 is fed into a bag making machine line 300. A seam adhesive applicator 308 applies seam adhesive 309 (see
The blank 500 in
In the bag making machine line 300 shown in a schematic representation in
The bottom adhesive applicator 313 applies bottom adhesive 311 to the end panel bottom portions 586a, 586b, and 596a, 596b as well as to the bottom corner portions 583a, 583b on the side of the blank 500 that forms the outer surface of the bag 618, as shown in
During the bag making process, inside vertical fold lines 503 are formed in the rectangular tube 320, and in the formed bag are located between the end sections 582a and 582b, and 592a, and 592b to aid in collapsing the bag 600 to a flattened state once formed. The inside vertical fold lines 503 extend from the top of the blank 515 to at least the horizontal collapsing fold line 505 of the finished bag 600. Near the bottom of the end sections 582a, 582b, 592a, 592b, two diagonal collapsing fold lines 587 extend towards what will be the bottom corners of the end walls 612, 616 once the bag 600 is formed. The fold lines 503, 587 enable the end walls 612, 616 to be folded into the center of the bag 600 such that the finished bag 600 can be folded flat. The sidewall sections 588a, 588b, 598a, 598b and the end sections 582a, 582b, 592a, 592b include a horizontal collapsing fold line 505 about which the bottom 614 can be folded when the bag 600 is folded flat. As described above, the bottom portions of the blank 586a, 586b, 589, 596a, 596b, and 593 are folded in on themselves by folders 314 to form the rectangular tube 320 into a bag 600.
After the bag 600 is formed from the blank 500, it is passed around a roller 318 under pressure in order to flatten the bag 600 and in some embodiments activate the pressure sensitive adhesive. The roller 318 holds all of the seams under pressure so that the seam adhesive 309 can set fully. The roller 316 also fully flattens the bags 600 so that they take up a minimum amount of space for storing and/or transporting.
The bags 600 can be stored for an extended period of time with the insulating material 110 in a dormant state. Keeping the insulating material 110 in a dormant state enables the bags 500 to be stored and/or shipped while taking up less space than they do once the insulating material 110 is activated.
In some embodiments, the amount by which the insulating material 110 expands upon activation may be reduced the longer the insulating material 110 is kept in a dormant state. The amount of insulating material 110 applied by the applicator 106, or the amount by which the insulating material 110 is pre-activated by the heater 112 can be adjusted in order to compensate for planned extended lengths of storage in a dormant state.
In order to fully activate the insulating material 110 so that the microspheres are fully expanded, heat is applied to the finished bag 600 in a thermal insulation activation machine line 400. In one form shown in
A number of different methods can be used to expand the bags 600. In a preferred embodiment, the bag opening station 403 includes vacuum lines are used to grip either bag side wall 610, 615 and pull the side walls apart causing the end walls 612, 616 to unfold along the crease 503. Preferably the bag 600 is only partially opened, i.e., with the top opening 602 smaller and side walls 610, 615 closer together than when the bag is fully opened, so that it is easier to collapse the bag again after post-activation or heating. In alternative embodiments, the bag opening station 403 expands the bags 600 by directing air flow into the mouth 602 of the bag 600 such that the pressure differential expands the bag.
Once the bags 600 are opened, they are fed, either vertically or horizontally with one side 610, 615 of the bag laid down, to a heating station 410 which is heated by a heater 411, such as a convection oven or microwave heater. The bags are carried into the heating station 410 by a conveyor belt 402. Laterally extending fins 404 define spaces that are slightly larger than the height of the bags on the conveyor belt 402 on which bags 600 are placed. The fins 404 keep the bags 600 from sliding around on the conveyor belt 402 as a result of air currents or from contacting the flaps 412 of the heating station 410. The heater 411 can be one of a variety of heaters including convection, conduction, radiation, microwave, or infrared. In some embodiments, the heater 411 employs a combination of heating methods. In one preferred embodiment, the heater 411 is a hot air heater or convection heater. The temperature of the heater 411 varies based on the speed of the conveyor belt 402. The faster bags 600 move through the heater 411, the higher the temperature needs to be in order to fully activate the microspheres. In one form, the conveyor 102 advances the bags 600 through the heating station 410 at a rate of 5 to 200 bags per minute. In one preferred form, the insulating material 110 is heated to a temperature between 200 degrees Fahrenheit and 250 degrees Fahrenheit in order to activate the microspheres. In a more preferred form, the insulating material 110 is heated to between 225 degrees Fahrenheit and 231 degrees Fahrenheit. Heating of the insulating material 110 to a temperature above 250 degrees Fahrenheit may cause over expansion and rupturing of the microspheres. The oven temperature is set at a higher temperature than the target temperature of the insulating material in order for the insulating material to reach its target temperature. In another preferred form, the temperature of the heater 411 is set between 330 degrees Fahrenheit and 450 degrees Fahrenheit. Once fully expanded, the thickness of the insulating material 110 is 10-60 times thicker than in an unexpanded form or, in a preferred embodiment, 20-40 times thicker.
In some embodiments, the heater directs heat directly to each wall of the bag 600. Hot air nozzles, microwave emitters or waveguides, or infrared heaters can be built into the ceiling, conveyor frame, and guide rails of the heater 410, each being directed towards the bags 600.
The heater 411 may include rubber flaps 412 at both the inlet and the outlet. The rubber flaps 412 are configured and sized to lessen the hot air flow out of the heater 411 from the entrance opening and the exit opening. In particular, the flaps 412 together should cover at least a majority of the inlet and outlet openings of the heater, and preferably at least 75 percent of the inlet and outlet openings. This reduced air flow enables the heater 411 to maintain an elevated working temperature with less energy.
After the insulating material 110 is fully activated by the heater 410, the bags 600 may then be conveyed to a cooling station 414 and into a cooler 415. The cooler 415 may operate by directing cool air towards the bags. The cooler 414 rapidly reduces the temperature of the bags 600 and the insulating material 110 so that they can be handled more comfortably and so that the insulating material 110 stops expanding. In alternative embodiments, the cooling station 414 may be removed.
The cooled bags 600 are then collapsed by a bag collapser 416. As shown in
The flattened bags 600 can then be packaged for shipping with a packing station 418. The elastic qualities of the insulating material 110 allow the bags 600 to be partially compressed for shipping. Once the bags 600 reach their destination, the bags 600 are unpacked to allow the insulating material 110 to bounce back to part of its full expanded volume up to near its full expanded volume.
In an alternate embodiment for forming insulating sheets, pillows, or pads or inserts 700 instead of bags 600, the laminate 205 containing inactivated or partially activated insulating material 110 is conveyed into the insert making machine line 350, as shown in
The insert in accordance with the disclosed forms is capable of keeping food products, such as pizza, warmer than conventional cardboard inserts. For example, a pizza with a starting temperature of 200 degrees Fahrenheit is placed within a pizza box on top of the insert 700. After 20 minutes in a standard ambient temperature environment, e.g., 70 degrees Fahrenheit, the pizza can be kept above at least 150 degrees Fahrenheit, and 20 degrees Fahrenheit warmer than an identical pizza with the same starting temperature placed in a standard pizza box without an insert 700.
After the insulated laminate 205 is cut into the desired shape of the inserts 700, the inserts 700 are then conveyed to a heating station 354 and into a heater 355, as shown in
Once the insulating material 110 is fully activated, the inserts 700 are packaged at a packing station 356. As with the bags 600 above, the elastic qualities of the insulating material 110 allow the inserts 700 to be compressed for shipping.
In an alternative embodiment, the heating station 354 and the heater 355 thereof is removed from the machine line 350. The inserts 700, or other finished products such as bags 600, are packaged and shipped without the insulating material 110 being fully activated. A heating station 354 can then be used at a remote location, such as a regional distribution center or at the end user's facility, such as a restaurant, to fully activate the insulating material 110. In a still further alternative, the insulating material 110 can be fully activated by the heat of the food product in the final container if the food temperature is hot enough.
In some embodiments, the thickness of the insulating material 110 applied by the applicator 106 and/or the amount of activation caused by the heater 410 or 354 are adjusted based on how long the bags 600 or inserts 700 are to be stored and/or shipped in a compressed state. The longer the bags 600 or inserts 700 are compressed, the less they tend to re-expand when released. Thus, bags 600 or inserts 700 that will be compressed longer can be made with more insulating material 110 or insulating material 110 that has been expanded to a greater degree in order to achieve the same final post-shipping and post-storage thickness. The amount by which compression reduces the thickness of the insulating material 110 can further be reduced by cooling the insulating material 110 prior to compression.
In some embodiments, the insulating material activation machine line 400 is located at a satellite site near where the end products will be used. By placing an insulation activation machine line at multiple locations throughout the country and/or throughout the world, the end products can be shipped in an unexpanded state in order to save on shipping costs. The end products may even be activated at the site of the end user.
In alternative embodiments for forming a bag 600, the activation machine line 400 is combined with the bag making machine line 300 to form a single, continuous line. In such a process, the roller 318 shown in
In additional alternative embodiments, all the machine lines 100, 200, 300/350, 400 are combined into a single continuous machine line. The first and second machine lines 100, 200 are combined as described above with the second machine line 200 feeding directly into one or both of the product forming machine lines 300/350. Additionally, the insulation activation machine line 400 can be integrated into the bag forming machine line 300 in any of the ways previously described.
The single, continuous machine line may utilize microwave heating. In this case, the insulating material 110 applied by the applicator 106 may be activated while the insulating material 110 is still wet. Accordingly, the drying heater 112 may be removed, and the insulating material 110 remains wet until activation. The activation heating stations 410/354 are replaced with industrial microwave heaters. The water in the insulating material 110 converts the microwave energy into thermal energy, causing activation/expansion of the microspheres. In some forms the insulating material 110 for microwave activated applications has a viscosity of between 2,000 and 6,000 centipoise at room temperature, i.e., 72 degrees Fahrenheit. In a preferred form, the insulating material 110 has a viscosity of between 3,000 and 4,500 centipoise at room temperature. In one example the insulating material 110 used is Aquence® ENV 42001 MFA available through Henkel Corporation.
In an alternative embodiment, microwave heatable materials other than water are included in the insulating material 110 so that the insulating material 110 can be dried by the heater 112 and stored in a dormant state without sacrificing the ability to activate by microwave later in the process. Exemplary substitute materials include ionic salts and carbon black.
In an alternative embodiment, the insulating material 110 is fully activated by the heater 112 prior to forming the laminate 205. The laminate making machine line 200 forms a laminate 205 using a first substrate 102 having the fully activated layer of insulating material 110 and the second substrate 202. The bag making machine line 300 then folds and glues that laminate 205 into a bag 600 and/or the insert making machine line 350 cuts the laminate 205 into inserts 700 without the need for subsequent heat activation of the insulating material.
In still further alternative embodiments, the insulating material 110 is activated after the laminate 205 is formed but before the laminate 205 is made into final products, such as bags 600 or inserts 700. An inline heater similar to the heater 112 is placed after the laminating adhesive applicator 206 in the laminate forming machine line 200. The new heater fully activates/expands the microspheres in the insulating material 110.
A printer 208 may be added to one of the machine lines 100, 200, 300, 350, 400 in order to print labeling, trademarks, or other information onto the bags 600 and/or inserts 700. The printer can be implemented at any point of the process. In a preferred embodiment, the printer is not placed immediately before or after a heater so that the ink has time to set at ambient temperatures. In a preferred embodiment, the printer is integrated after the substrates 102, 202 are cut into blanks 500 or inserts 700 and/or folded into bags 600 to reduce the chance of the printed mark being out of alignment on the end product.
In some embodiments, the pattern of insulating material 110 is configured such that the total percentage of the end product by weight that is insulating material 110 is low enough for the end product to be recyclable and/or repulpable. In further embodiments, the insulating material, various adhesives, and barrier coating may be composed of compostable materials, such as starch, so that the end product is compostable.
In one form, the bag 600 has a footprint size, or dimensions of the bottom wall 614, when expanded of about 11.5 inches by 7 inches and a height of its upstanding side and end walls 610, 615, 612, 616 of about 20 inches. In some embodiments, there are horizontal creases 505 on the sidewalls and end walls 610, 615, 612, 616 roughly 3.5 inches up from the bottom along which the bag 600 is folded when collapsed into a flattened state. In still further embodiments there are horizontal creases 508 in the sidewalls and end walls 610, 615, 612, 616 roughly 3 inches down from the mouth 602 about which the top can be folded and then sealed (e.g., with a sticker, tape, and/or staples). The uninsulated portion 611 includes the top 7 inches of the bag 600. However, many different shapes and sizes of bags 600 are contemplated.
In operation, the insulated bag 600 is intended to be used to store perishable items, such as cold groceries at or below a threshold temperature during transportation and/or delivery. In an exemplary operation, the insulated bags 600 can be used to deliver groceries, enabling the groceries to be left outside at the recipients' door for hours in summer conditions while minimizing the possibility of frozen food thawing or refrigerated food from becoming dangerously warm.
For example, the bag 600 with the insulating material layer 110 having an expanded thickness of 0.2 inches once activated can meet certain performance characteristics. For example, a bag, having a height of twenty inches prior to closing the bag, filled with a half-gallon milk container and two 5.3 oz. yogurt cups starting at a temperature of 36 degrees Fahrenheit with the bag upper area 611 rolled down 3 inches to a closed height of seventeen inches was able to keep the rise of temperature of milk and yogurt to less than 30 degrees Fahrenheit at an ambient temperature of 85 degrees Fahrenheit for 3.5 hours without the aid of any additional chilling via ice packs or dry ice. At an ambient temperature of 110 degrees Fahrenheit, the bag 600 can keep the increase in the temperature of the milk and yogurt starting at a temperature of 36 degrees Fahrenheit to less than 30 degrees Fahrenheit for an hour without the aid of any additional chilling via ice packs or dry ice. The bag 600 keeps the rise of temperature of the same milk and yogurt starting at 36 degrees Fahrenheit to less than 30 degrees Fahrenheit at an ambient temperature of 93 degrees for 1.15 hour, and then 110 degrees Fahrenheit ambient for 2.15 hours in a total 3.5 hour time frame with the aid of 2-3 lbs of chill packs of ice.
In another example, the bag 600 keeps the rise of temperature of a half-gallon container of ice cream and one pound bag of frozen fruit starting at a temperature of zero degrees Fahrenheit to less than 20 degrees Fahrenheit at ambient temperatures of 85 degrees Fahrenheit for 3.5 hours without the aid of any additional chilling via ice packs or dry ice. At an ambient temperature of 110 degrees Fahrenheit, the bag 600 can keep the increase in the temperature of ice cream and frozen fruit to less than 20 degrees Fahrenheit for an hour without the aid of any additional chilling via ice packs or dry ice.
In an additional example, when 400 grams of ice are placed in the bag 600, the upper portion 611 is rolled or folded to seal, and then the bag 600 is left in a 109 degree Fahrenheit environment some unmelted ice remains after 4 hours.
In some embodiments, the laminate 205 with fully activated insulating material 110 has an R-value ranging from 0.05 m2 K/W to 0.5 m2 K/W.
In some embodiments, an insert 700 can further include a moisture absorbent material, a phase change, and/or a heat releasing material or method. As described above one or both of these elements can be integrated with the insulating material 110. Alternatively, a layer of superabsorbent or desiccant material can be added to the insert 700 separate from the insulating material 110 or in place of the insulating material 110. Additionally, a layer of phase change material or heat releasing material can be included in the insert 700. The heat releasing material may simply be a phase change material that is a heat sink that absorbs heat and slowly releases it, such as sodium acetate, a phase change material that releases heat as it changes phases at a certain temperature, or a material that undergoes an exothermic reaction with steam or condensate, such as synthetic zeolite. If an absorbent material and/or a reactant are included in the insert 700 one or both substrates 102/202 may be perforated to allow steam and/or water to flow into the insert and interact with the absorbent or reactant material.
Another preferred form for forming an insulated collapsible bag 600 using a single, continuous machine line is shown in
Once the bag 600 is formed, the laminating adhesive 207 keeps the insulating material 110 from escaping from between the substrates 102, 202 by sealing each edge of the bag. For example, in use, flexing of the bag 600 may cause insulating material bonded to one or both of the substrates to become loose and become free to move about within the walls of the bag. Accordingly, the laminating adhesive 207 may be applied to form a continuous perimeter about the insulating material 110 such that the bonded substrates form sealed edges around the insulating material. However, in some forms the adhesive 207 may be applied in a discontinuous manner in one or more locations if desired. In particular, it has been discovered that having a portion of the unexpanded laminate with an edge that is not completely sealed allows moisture to escape from between the substrates when the insulating material is heated, which allows for improved expansion of the insulating material. For example, the adhesive seam along the top edge 515 of the first substrate 102 of blank 500 (See
The first substrate 102 is then advanced in a machine direction to an insulating material applicator 106. In this embodiment, the applicator 106 is a series of nozzle applicators. The nozzle applicators apply the insulating material 110 in liquid form to a first side or surface 101 of the first substrate 102. The second side or surface 103 of first substrate 102 may be pre-treated with a water barrier coating. The insulating material 110 is an expandable insulating material activated by heating, such as Aquence® ENV 42001 MFA.
In one form, the nozzles are stainless or more preferably ceramic ribbon coat nozzles. As the first substrate 102 moves under the nozzle applicators, independently controllable valves connected with each nozzle applicator open intermittently to apply rectangular sections of insulating material 110 through the nozzle applicators. In one form, the insulating material 110 is applied in 1 inch×0.75 inch rectangles by each nozzle. The nozzles are arranged in one or more banks or rows, and preferably two separate rows. In one form for applying insulating material to form a flexible laminate that will be formed into a collapsible bag, one row includes 14 nozzles and 14 corresponding valves, and the second row includes 13 nozzles and valves, for a total of 27 independently controlled nozzle applicators. The each bank of nozzles is connected to a separate supply manifold which has its own pressure regulator, such that the insulating material 110 is supplied to each of the nozzles in a bank at substantially the same pressure. The nozzles in the second row are arranged to be offset from the nozzles in the first row so that two rows of nozzles apply insulating material 110 arranged in a pattern of individual spaced apart portions, such as rectangles, that are aligned in a plurality of columns. For example, a nozzle application system with 27 spaced apart nozzles applies insulating material aligned in 27 separate columns, with the individual portions of insulating material within a column spaced apart from one another. A plurality of rows of offset nozzles can be used to create tighter patterns. The nozzle application system can be sourced from the Valco Melton company. The substrate 102 is advanced by the conveyor system under the nozzles at a speed of between 150 and 250 feet per minute. In one form, the substrate 102 moves at a speed of approximately 200 feet per minute. A flow meter can be used to measure the volume of insulating material 110 applied by the applicator system to portion of the substrate that will be used to form a single bag. If the amount of insulating material, is outside of a predetermined range, the substrate can be marked to indicate a defect for later removal from the line, such as after the laminate has been formed into a bag.
After the applicator 106, a vision system 109 (such as shown in
After the insulating material 110 is applied, the first substrate 102 and the second substrate 202 are bonded together via the previously applied laminating adhesive 207 at laminating station 200 using nip rollers to form an unexpanded laminate as previously described.
In some forms, the first substrate 102 and the second substrate 202 are two portions of a single ply or sheet 1602 of material, as illustrated in
After lamination, the unexpanded laminate is fed directly into a bag making system or converter 300. The bag making system 300 is described in greater detail above. The bag making system 300 outputs discrete, folded collapsible bags 600 with unexpanded insulating material 110 disposed within the base and walls of the bag. The bags 600 are then fed into a heating station 400 for activation. In some forms, the bags 600 are stored before being activated. In alternative embodiments, such as shown in
The oven 1310 includes a chamber with wave guides configured to direct microwaves from a microwave generator 1311 through the bags 600 being conveyed through the oven 1310. The microwaves cause the water, or other microwave sensitive material in the insulating material 110 to be heated to activate and expand the microspheres in the insulating material.
The heating station 1300 shown has a single port or wave guide connecting the microwave generator 1311 to the oven 1310. In alternative embodiments a multi-port system could be used.
The temperature to which the insulating material 110 is heated depends on a number of factors, including the power of the microwave generator 1311, the length of the oven 1310, the formulation of the insulating material 110, including the water content thereof, the geometry of the bag, and the speed at which the bags 600 travel through the oven 1310. In an exemplary form, the oven is 12 feet long, the bags 600 travel up to 200 feet per minute, and a 100 kW 915 Mhz microwave generator is used. The actual line speed achievable will be determined by the length of time needed in the oven for the insulating material to reach the desired temperature. For example, using a longer microwave oven will allow a faster conveyor speed to be used.
The oven 1310 includes temperature sensors, such as infrared sensors, for measuring the temperature of the bags 600. Because the infrared sensors cannot measure the temperature of the insulating material 110 directly, which is contained between the substrates 102, 202, the sensors are configured to measure the surface temperature of the bag 600 proximate sections of insulating material 110. Preferably the surface temperature during activation reaches between 130° and 180° Fahrenheit. In some forms, the heating system 400 is configured to alter the speed of the conveyor 402 based on the measured temperature such that the insulating material 110 within the bags 600 is fully activated before exiting the oven 1310.
After activation of the insulating material 110, the finished bags 600 are transported from the oven 1310 along a cooling conveyor 414. The cooling conveyor 414 exposes the bags 600 to ambient air for sufficient time to cool them. In some forms, the cooling conveyor 414 may include a cooling tunnel, fans, and/or other cooling devices to expedite cooling. After the bags are cooled they are transported to the bundling station 418. In the bundling station 418 a plurality of bags 600 are stacked, bundled, and prepared for shipping.
Similar to the inserts disclosed in
As shown in
Each end wall 1472 is connected to each sidewall 1474 by a gusset or webbing 1476. Each gusset 1476 is divided into two triangular sections 1477 by a crease or fold line 1475. The end walls 1472, sidewalls 1474, bottom panel 1471, and top wall portions 1473 each contain insulating material 110. The gussets 1476 do not contain insulating material.
In operation, the insulated laminated insert 1470, see
The container and insert 1470 can then be loaded with items before folding the top portions 1473 along fold lines 1473a by approximately 90 degrees relative to the walls 1472 to rest above or on top of the contained materials. In alternative embodiments, the size and shape of the inserts 1470 vary to be configured to fit in different containers.
The machine system 1400 shown in simplified form in
The insulating material 110 is applied to the first substrate by the applicator in columns of sections 111. After application the visual inspector or vision system 109 inspects the pattern as described above. An adhesive applicator 206 applies a seam adhesive 207 proximate the borders or edges of the insert 1470. In a preferred form, the insulating material 110 is completely surrounded by adhesive on the surface 101 of the substrate 102, such that when the laminate 205 is formed the seam adhesive 207 provides a seal to inhibit passage of the insulating material 110 from between the substrates 102, 202. The second substrate 202 is applied to the first surface 101 of the first substrate 102, and the two substrates are pushed together by nip rollers 204. In some forms, the rollers 204 comprise a series of rollers positioned to compress the laminate 205 along the seam adhesive 207 but not the insulating material 110.
As shown in
In some forms, such as shown in
In the conventional oven system 1400, a die cutter 352 cuts the laminate 205 into blanks 1479, see
As shown in
After being formed and activated, the inserts 1470 are stacked and bundled for shipping. In one form, the inserts 1470 are shipped in the flat position shown. The inserts 1470 can then be folded up at a second location for being inserted into a container to be insulated prior to loading the container, for example distribution centers for grocery or prepared meal delivery.
In some forms, the insulating material 110 is applied in three different spaced apart sections as shown on the insert blank 1679 in
A seam adhesive applicator 206 applies a seam adhesive 207 along the exterior edge 1671 of the first substrate section 102. In some forms, the seam adhesive applicator 206 also applies seam adhesive in lines perpendicular to the side edge along what will be the ends of the insert 1670.
A tilter or folder 1610 folds the second substrate section 202 over to cover the first side 101 of the first substrate section 102 to form an unexpanded laminate 205. The folder 1610 includes one or more of rails or rollers to gradually fold the sheet 1602 in half along fold line 1673. After folding, a roller 204 presses the two substrate sections 102/202 together along the seam adhesive 207.
In the system 1600 shown, the laminate 205 enters a microwave heater 1310. The microwave oven 1310 operates substantially similar as described above. In alternative forms, a conventional heater 410 is used to activate and expand the insulating material 110. For systems 1600 with conventional heaters 1410, a dryer 107 may be used to pre-dry the insulating material 110 upstream of the folder 1610. As shown, at least the upstream end of the laminate 205 remains open during the microwave process such that moisture is allowed to exit the laminate while the insulating material is being activated.
After activation, the ends 1671 of the inserts 1670 are crimped by a crimper 1675. The crimper 1675 may additionally crimp the side edge of the laminate 205 along the seam adhesive 207. The substrate is then cut along the end crimps to form discrete inserts 1670. A polymer coating may also be applied to the inner surface of the substrate 102, such that when heat is applied by the crimper 1675, the polymer coating melts and bonds the substrate sections together. Accordingly, the edges of the insulated laminate insert may be sealed by seam adhesive 207, a melted polymer coating, and/or the mechanical bond formed by crimper 1675.
Turning to
The seam adhesive applicator 206 applies the seam adhesive 207 along what will be the side edges of the insert 1770. In some forms, the seam adhesive is applied in four longitudinal strips. Two strips are located proximate the side edges of the first substrate 102. Two other strips are located proximate the center line 1711 of the first substrate 102. In some forms, the two center strips are connected such that they form a single, double-wide strip. The insulating material 110 is positioned between an outside strip and the nearest center strip such that when the expanded laminate 205 is formed and is split into inserts 1770, the insulating material 110 is sealed within the substrates 102, 202 on both sides of the insert 1770 by a strip of seam adhesive 207 along outer side edges of the insert 1770.
The second substrate 202 is then applied to the top surface 101 of the first substrate 102 and the two are pressed together by nip rollers to form an unexpanded laminate 205. In some forms, a dryer 107 partially pre-dries the insulating material 110 before lamination. In a preferred form, the dryer 107 is used in line 1700 with a conventional heater 410.
The laminate 205 is fed into a conventional oven 410 to activate the microspheres in the insulating material 110, causing the insulating material 110 to expand. The heater 410 is a conventional heater as the heaters 410 described above. Alternatively, a microwave oven 1310 can be used. In some forms a temperature sensor, visual sensor, and/or gauge is used as quality control to monitor the activation process by measuring the surface temperature of the laminate 205 and/or the thickness of the laminate 205 after activation.
After activation, the laminate 205 is fed into a cutter 1775. The cutter 1775 cuts the laminate 205 into discrete inserts 1770. In some forms, the cutter 1775 additionally crimps the edges of the inserts 1770. The cutter 1775 may comprise a plurality of separate machines for performing different cutting and crimping processes. The cutter 1775 includes a slitter positioned and configured to continuously slit along the longitudinal axis of the laminate 205 splitting the laminate into two inserts 1770. A crimper creates crimps perpendicular to the slit and spaced apart to define the sealed ends of the individual inserts 1770. In some forms, the crimps are 35 inches apart on center. A cutter cuts along the width of the laminate 205 proximate the center of each crimp dividing the laminate into individual blanks 1770. After cutting, the inserts 1770 are stacked and prepared for shipping. The inserts 1770 may be used as insulated inserts for packages, such as grocery or food delivery packages.
In some forms, as illustrated in
The system 1800 shown in
After perforation, the laminate 205 is rolled into a roll 1871. The roll 1871 can then be transported to a second location or stored for future use.
It is thus seen that a flexible laminate with a thermally activated expanded insulating material positioned between the two plies of the same or different kinds of substrate, and products made from said laminate, including bags and inserts, may be provided and used in accordance with the foregoing teachings.
In addition, one skilled in the art will appreciate variations in the above-described flexible insulating laminate and products made therefrom can be provided. For example, the laminate 205 can be formed into envelopes or sleeves or other flexible containers. Additionally, one skilled in the art will appreciate that a variety of methods and systems for making an insulated laminate are contemplated in addition to those explicitly described above.
Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations, are to be viewed as being within the scope of the invention.
This application claims the benefit of U.S. Provisional Patent Application 62/428,093, filed Nov. 30, 2016, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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62428093 | Nov 2016 | US |