HK1210123B - Thermally activatable insulating packaging - Google Patents

Abstract

A package or container includes a side wall, the side wall having an inner surface and an outer surface. At least one of the inner surface or the outer surface of the side wall may be at least partially coated by a layer of a thermally expandable material. The material may be adapted to be expanded to provide thermal insulation.

Description

Thermally activatable insulating packaging

RELATED APPLICATIONS

U.S. provisional patent application No.60/789,297, filed 2006, 4, 3, is hereby incorporated by reference in its entirety for all purposes based on the benefit of 35u.s.c. § 119 (e).

This application is a divisional application of the invention patent application "thermally activatable insulating wrapper" filed on 27/03/2007 with application number 200780018298.7.

Technical Field

The present invention relates to a thermally activatable insulating packaging.

Background

Consumers typically purchase ready-to-use products, such as food and beverages, packaged in disposable containers. The insulated container may be designed for hot or cold liquids or foods, such as hot coffee, iced tea or pizza. These containers maintain the temperature of the liquid or food contents by preventing heat or cold from being transferred from the contents into the consumer's hands.

Disclosure of Invention

A package or container includes a sidewall having an inner surface and an outer surface. At least one of the inner surface or the outer surface of the sidewall is at least partially coated with a layer of a thermally expandable material. The material may be adapted to expand to provide thermal insulation.

Other systems, methods, features and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.

Drawings

Fig. 1 is a perspective view of a cup assembled with a die cut blank.

FIG. 2 is a perspective view of a cup assembled with a full cup die cut blank with an opening.

Fig. 3 is a perspective view of another unitary container having a channel.

Fig. 4 is a cross-sectional view of the assembled die cut blank.

FIG. 5 is a top perspective view of a cross section of a cup assembled with a die cut blank.

Fig. 6 is a view of a die cut blank disassembled from a cup.

Fig. 7 is a view of a die cut blank disassembled from a cup.

Fig. 8 is a view of a die cut blank disassembled from a cup.

Fig. 9 is a view of a die cut blank disassembled from a cup.

Fig. 10 is a view of a die cut blank disassembled from a cup.

Fig. 11 is a view of a die cut blank disassembled from a cup.

Fig. 12 is a view of a cup assembled with a die cut blank, illustrating heat conduction.

FIG. 13 is a side cutaway view of a double wall cup.

FIG. 14 is a block diagram of an exemplary process of applying a particulate coating to a substrate.

Fig. 15 is a schematic view of applying a coating to a substrate through a spray nozzle.

Fig. 16 is a schematic view of applying a coating to a substrate through a non-spray nozzle.

Detailed Description

A package or container may be constructed from and/or insulated by a die cut blank, such as a sleeve. The die cut blank may be fixed to the container or the die cut blank may be removable. The thermally expandable material may be applied to the container and/or the die cut blank. Expandable materials that do not expand by temperature may also be used. The material may expand prior to reaching the end user, such as in the manufacture of the container and/or die cut blank, and/or the material may expand only at the end use and only in response to a determined temperature. The material may be employed to aid in the insulative properties of the container and/or die cut blank and/or to increase the rigidity of the container and/or die cut blank, such as by reducing the thickness of the material components of the container and/or die cut blank.

Fig. 1 shows a container 101, such as a cup, and a die cut blank 102, such as a sleeve. The container is described as a cup, for example, but may also include other containers such as a plate or a basin. The blank may be in the form of a sleeve for a container or in the form of an outer wall for a container. The container is not limited to a cup but may be any other container including, but not limited to, a bulk coffee container, a soup can or an extruded container with or without a lid or sleeve. The container 101 may be a cylindrical cup or a container having other geometric configurations, including conical, rectangular, etc. The die cut blank is not limited to a corrugated die cut blank and may be constructed of paperboard, paper, or the like. The die cut blank 102 may be made from any conventional paper stock including, but not limited to, natural single facer paper, white-edged single facer paper, bleached-edged coated single facer paper, corrugated paper, fluted corrugated paper, or any combination thereof. The die cut blank 102 may be removable from the container or the die cut blank may be adhered to the container 101. The blank 102 may be adhered, for example, by laminating the die cut blank to the container using hot melt, cold melt, and/or any other gluing or sealing means. Alternatively or additionally, the blank may be adhered by an expandable material, such as a microsphere material. If the die cut blank is attached to the cup during manufacture, efficiency is increased due to the elimination of the assembly step by the end commercial consumer. Moreover, it may reduce the amount of storage space required by the end commercial consumer, e.g., only one item may need to be stored instead of two.

Fig. 1 is not necessarily drawn to scale. For example, the die cut blank 102 may cover more or less of the surface portion of the container 101 than shown. For example, the die cut blank may provide full coverage. Increasing the surface area of the die cut blank 102 may provide a larger insulating area and a larger printing surface. Although the figures show the die cut blank on a cup, the die cut blank may be added to any other container, such as, but not limited to, bulk beverage containers, press formed containers, soup cans, and the like.

A thermally activatable coating may be applied between the container 101 and the blank 102. The expandable material may be thermally activated by hot or cold temperatures, and may be an expandable coating or adhesive, including but not limited to adhesives, expandable microspheres or other microencapsulated particles, pigments or other additives, or any combination of these or other materials. The material is swellable when wet or dry. The material may comprise any synthetic or natural material, including water-based, solvent-based, high solids, or 100% solids materials. The solids content is generally from 30% to 80%, more preferably from 40% to 70% of the material. Additional ingredients may be added to the adhesive including, but not limited to, adding pigments or dyes, fillers/extenders, surfactants for dispersion, thickeners or solvents to control tack for optimal application, defoamers, additives such as waxes or emulsifiers, and the like. Alternatively, the adhesive may be a glue. The expandable material may have several properties, including, but not limited to, thermal insulation to keep the container contents hot or cold, and/or it may expand upon contact with a hot material (e.g., over 150F.) and preferably remain in an inactive state until a designed activation temperature is determined, such as at about room temperature. The coating may be repulpable, recyclable, and/or biodegradable.

Fig. 2 and 3 show a container 101 having an outer wall of a die cut blank 102. The container 101 may be configured as a double wall cup assembly. The container 101 may be a cylindrical cup or a container having other geometries, including conical, rectangular, and the like. The die cut blank may partially or completely cover the body of the container. The die cut blank 102 may be an exterior wall of the container 101. The container 101 and the die cut blank 102 may be integrally combined into the cup 100 and an expandable material or adhesive may be applied between the container body 101 and the die cut blank 102. The activatable material may additionally have adhesive properties so that a unique attachment can be formed between the container and the blank. The die cut blank 102 may be made from any conventional paper stock including, but not limited to, natural single facer paper, white-edge single facer paper, bleached-edge coated single facer paper, or any combination thereof. The die cut ingredients and/or containers may be pulpable, recyclable, and/or biodegradable. The die cut blank 102 may, for example, include corrugations, flute corrugations, or raised grooves. The grooves may be in a vertical direction, diagonally or in other directions and may spread the heat of the handle away.

The die cut blank 102 may be removable from the container or the die cut blank may be adhered to the container. For example, a one-piece container 101, such as a cup, may be manufactured by laminating the die cut blank to the container using a hot melt and expandable material or any other adhering or sealing method to secure the die cut blank. Alternatively, a heat activated material may be used to adhere the blank to the cup. If the die cut blank 102 is permanently attached to the container 101 during the manufacturing process (e.g., creating an integrated one-piece cup), the efficiency of using a hot die cut blank is increased due to the elimination of the assembly step by the end commercial consumer. Moreover, it may reduce the amount of storage space required by the end commercial consumer, e.g., only one item may need to be stored instead of two.

The die cut blank may remain open-ended on one side or on opposite sides, which allows airflow. For example, in fig. 2, the container may include an opening 210 near a top 212 of the integrated container 100. The opening may be formed into the die cut blank, for example, in the form of a hole, and an air flow may be created when the space between the container 101 and the die cut blank 102 is expanded by the expandable material. The air flow may be directed, for example, upward, and away from the gripping fingers, by a corrugated, fluted corrugated, or other passageway in the die cut blank 102 or expandable material application pattern 216. For example, the pattern of application of the expandable material may create thermal release channels 216.

FIG. 3 illustrates an alternative non-limiting embodiment of how expandable material may be applied near the top 212 of the container 101 to form an opening 310. These channels may be formed when the material expands. There may be openings on opposite ends of the container 101, such as at the top 212 and bottom 214. These openings may be formed by rolling the die cut blank over the container without completely sealing the top 212 or bottom 214.

Fig. 4 shows a cross-section of the die cut blank 102 assembled with the cup 101. The drawings are schematic and not limiting. The cup may be replaced by any container, for example, a press formed tray, a soup can or a bulk beverage container. The die cut blank 102 may have an inner surface 406 and an outer surface 404. The expandable material may be applied to the inner surface 406, the outer surface 404, and/or to the surface 402 between the inner surface 406 and the outer surface 404. The inner surface 406 and the outer surface 404 do not necessarily contain the space 402. In another non-limiting embodiment, an expandable material can be applied between the container wall 101 and the die cut blank 102 to form the unitary container 100.

The thermally expandable material 408 may be applied to the inner surface 406 of the die cut blank 102 in an inactive manner. The inactive material 408 may be applied in the form of a film so that the film does not materially affect the thickness of the die cut blank 102. Applying the expandable material to the interior of the die cut blank may also maintain the printability of the outer surface of the die cut blank. The non-reactive expandable material 408 on the die cut blank 102 may maintain the slim profile of the cup if assembled with, for example, a standard paper cup. The maintenance of the slim profile maintains the effective nesting properties of standard cups, allowing them to be efficiently packaged, boxed and shipped.

The expandable material 408 may be activated and thus expanded, for example, by adding hot liquid, beverage, or food to the container 101. Activation may only occur during the consumption stage and not during the processing stage of the die cut blank, such that the die cut blank 102 may be at the expandable materialThe material is delivered to the consumer in a substantially inactive state. For example, the activation point of the swellable material may be above about 120 f^oF and/or less than 60^oF, so that the expandable material can be activated only by the temperature of the hot liquid, beverage or food, and not by ambient or body temperature. Activation causes the expandable material to expand and "push back" the die cut blank 102 from the container 101, thereby creating an increased air gap. The air gap may form a thermal barrier between the hot beverage container 101 and the consumer's hand. Activation may also increase the rigidity and/or rigidity of the container, which may allow for a reduction in the material or thickness of the container wall. As will be described in more detail below, the container may also be activated or at least partially activated prior to reaching the consumer.

The expandable material 408 may be applied to the die cut blank 102 in an unexpanded state. Expansion of the die cut blank may not occur until activated by, for example, the addition of heated fluid or solid at the time of supply. This may be different than expanding the material during the manufacture of the die cut blank. Expansion during manufacture can increase the volume of the die cut blank. The expandable material can be controlled to achieve nesting efficiency. The properties of the die cut blank may be further controlled by, for example, but not limited to, combining a die cut blank constructed from fluted corrugated material with patterned application of an intumescent material to provide specific insulation, air flow characteristics, and container stiffness improvements. For example, the corrugations and/or the pattern of expandable material applied to the die cut blank may direct heat convection upward and thus may reduce heat conduction horizontally toward the consumer's hand. In other implementations, the expansion may be performed prior to shipping, e.g., prior to, during, or after the manufacture of the container.

Fig. 5 is a cross-section of a container 101 assembled with a hot die cut blank 102. The drawings are only schematic and are non-limiting. An expandable material 408 may be applied to the inner surface 406 of the die cut blank 102. For example, the expandable material 408 may be applied between the die cut blank 102 and the container 101 wall and may form an integral two-ply cup with a heat-activatable insulating expandable material between the two plies. The expandable material may include, for example, expandable microspheres 502 dispersed within a binder or any other suitable material exposed above 504 and may have adhesive properties.

Fig. 6 illustrates an exemplary die cut blank 602. The figures are schematic and are not intended to be limiting as to size or shape. The size and shape of which can be adapted to the dimensions of any container. The expandable material 408 may be applied to the die cut blank 602. The expandable material may be applied by a variety of methods, such as, but not limited to, nozzle spray guns, printing, slot coaters, or other methods such as will be described in more detail below. The expandable material 408 may be applied to the die cut blank 602, for example, on an in-line winder, in-line on a folder/gluer, or by other suitable methods such as off-line coating and drying. The expandable material 408 may be applied to the die cut blank 602 in any suitable pattern, such as, but not limited to, stripes, dots, corrugations, squares, circles, diamonds, random shapes, combinations of these or any other pattern. For example, the expandable material may be applied in a form that directs airflow vertically upward and/or conducts heat away from the fingers being held. The expandable material may be applied such that it forms a channel or expands upon activation to form a channel. These channels may direct natural convection. The expandable material 408 may completely or only partially cover the surface being coated.

The coated die cut blank may be removed or permanently attached to the container or cup, for example, by wrapping the die cut blank around the container. For example, the one-piece cup or container 101 may be manufactured by laminating the die cut blank to the container using a hot melt and expandable material to secure the die cut blank, using an expandable material with adhesive properties, a combination of these or any other adhesive or sealing method. If the die cut blank 102 is permanently attached to the container 101 during the manufacturing process (i.e., creating an integrated one-piece cup), efficiency is increased due to the elimination of the assembly step by the end commercial consumer. Moreover, it may reduce the amount of storage space required by the end commercial consumer (only one item needs to be stored instead of two items). The shape of the die cut blank shown in the drawings is not intended to be limiting. The shape of the die cut blank may be adapted to the shape of other containers such as, but not limited to, soup cans, press formed containers, or bulk beverage containers.

Alternatively, the die cut blank 602 may contain hot melt 604 or cold set glue in the seam. If the expandable material 408 is also a glue, the in-seam hot melt or cold set glue 604 may be omitted. In addition to the expandable material 408, an in-seam hot melt/cold set glue 604 may be used, for example, to enhance bonding. The die cut blank may be applied to the cup, for example, by winding, lamination, or other manufacturing methods.

Fig. 7-11 illustrate other embodiments of the die cut blank 402. These embodiments are merely illustrative, and not restrictive. Fig. 7 illustrates a die cut blank 602 in which expandable material 408 is applied in a pattern 709 to direct the release of heat. The die cut blank 602 may be made, for example, of corrugated paper, such as, but not limited to, fluted corrugated paper. Conduction may be directed by corrugation, a pattern of applied expandable material, or other suitable means.

Fig. 8 to 11 show other possible non-limiting embodiments of possible patterns of expandable material. The patterns of expandable material are denoted by reference numerals 809, 909, 1009 and 1109, respectively. The expandable material may be applied in a pattern different from that shown in fig. 7-11. The thickness of the pattern of expandable material 809, 909, 1009, and 1109, respectively, may vary and create a progressive flow to direct heat to the die cut openings. The die cut openings are indicated by reference numerals 814, 912, 1012 and 1112, respectively. The die cut openings may also be formed and/or include shapes such as represented by reference numerals 812, 914, 1014, and 1114. Die cut openings may be present at opposite ends of the blank or at only one end. The shape of the die cut openings in fig. 8-11 is merely illustrative and not limiting. For example, the pattern of expandable material and the shape of the die cut openings may be arranged to direct airflow such as, but not limited to, creating a Venturi (Venturi) effect.

FIG. 12 is an exemplary embodiment showing exemplary thermal conduction. This embodiment is not limiting, but merely illustrative of possible heat loss operations. The total heat loss of the system can be represented by the following equation:

Q^T[ card/sec ]]＝Q₁+Q₂+Q₃+Q₄

Wherein Q is^TIs the total heat loss. Q₁1204 is the heat loss due to water evaporation. Q, denoted 1202, 1206, and 1208, respectively₂、Q₃、Q₄May represent convective and conductive heat losses.

For the purpose of keeping the contents hot by bringing Q^TAnd minimized. Die cutting the blank by passing Q₂、Q₃And Q₄Minimize to Q^TAnd minimum. The low thermal conductivity of the expandable material may be due to Q₂、Q₃And Q₄Resulting in lower heat loss.

The purpose of preventing the body of the consumer from being burnt can be achieved, for example, by making Q₂、Q₃And Q₄Especially Q₂、Q₃Minimizing while allowing Q₁And Q₄This is achieved by directing the inevitably high heat flux (due to the hot fluid) vertically upwards or downwards. This can be achieved, for example, by adding flutes to the die cut blank. The grooves may be, for example, substantially vertical or diagonally inclined.

The following are non-limiting examples.

Example 1. Example 1 provides an illustration of how an expandable material can change thermal conductivity. The temperature inside the cup can be represented by Ti. The temperature outside the cup may be denoted by To. The upper line X represents the container without the die cut blank coated. The second line Y represents the container assembled with the coated die cut blank. This embodiment shows that in a container without the die cut blank 102 coated with expandable material, the difference between the inside and outside container temperatures is very small. In containers having die cut blanks coated with a temperature activated material, the temperature differential between the inside of the container and the outside of the container is small when hot food or beverage is added to the container. However, the food or beverage may activate material a upon contact, thereby causing the material to expand. The temperature difference Ti-To may increase as the material expands.

Example 2. Example 2 shows a comparison of the temperature feel of various die cut blank materials coated with a thermally expandable material and die cut blank materials not coated with a thermally expandable material. The following samples are exemplary only, not limiting, and other experimental results may be obtained.

Thermally or otherwise expandable material may be applied to die cut blanks made from various materials, such as, but not limited to, paper, paperboard, fluted corrugated paper. Each die cut blank may be wrapped around a container, such as a cup. The cup can be filled with hot water. The cup was then held with the bare hand and the sensory responses to the two conditions were compared. In each test, the cups with the coated die cut blanks felt less "hot" than the cups with the uncoated die cut blanks. The expansion takes place after a few minutes after the hot water has been poured into the cup.

Example 3. The coating may be applied to the single facer media by coating. The paint may expand when wet at a temperature of 600F degrees using a heat gun of MASTERMITE120V, 475W.

Example 4. The coating can be applied to the outside of the 12Oz cup and allowed to air dry overnight. Every other day, 190F hot water was poured into the cup. A significant expansion was observed shortly after the 190F hot water was filled into the cup. The lid can be placed on the cup and after 7 minutes a greater swelling, but still a partial swelling, is observed. The advantage of thermal post-excitation is that the hotter the liquid, the more the coating expands.

Example 5. The coating is applied to the cup. A250W IR heater, model 11-540-50, made by Fisher Scientific, heats the coating. The expansion was slower when the lamp was 6 inches away from the paint, and immediately when it was 1 inch away from the paint. Excessive heat and time will cause the coating to deform on the substrate surface.

Example 6. The coating may be applied to the paper and then the paper is wound onto a paper cup after the coating has dried out. The portion of the coating that passes indirectly through the paper shell may be heated for one minute using heat from the heat gun. The coating expands. Another portion of the unheated coating may be heated by the paper under an IR lamp. The coating expands.

FIG. 13 is a side sectional view of a double walled container 101. The double-walled container 101 may form an air shield between the outer wall 1300 and the contents 1302 (filled with hot or cold beverage or food) of the container 101. The air hood can be used for the temperature T of the outer side surface₀Providing thermal insulation. The air shroud may partially or completely surround the container 101. The pressure exerted on the outer wall 1300 when holding the container 101 acts to collapse the outer wall 1300 at the point of pressure to reduce the air cap and potentially initiate contact with the inner wall 1304 of the container 101. The air shroud may collapse at the pressure point and create a feeling of low stiffness, and this contact may create a hot spot on the outer wall 1300 if the thermally expandable coating 216 is not used.

If a sufficient amount of coating 216 is employed, coating 216 may function to provide rigidity without disrupting the thermal insulation of the air jacket relative to outer wall 1300, such that outer wall 1330 does not collapse in whole or in part. The coating 216 may add mechanical strength to the container 101. Due to the increased mechanical strength of the coating 216, the container 101 may be fabricated from lightweight materials, which may reduce the source materials of the substrate forming the container 101. Coating 101 may be applied to inner wall 1304, outer wall 1300, or both in a dotted (e.g., dot) or other pattern, such that coating 216 forms an air gap and prevents container 101 from collapsing under the holding pressure. The coating 101 may also provide a rigid feel to the user while allowing for a reduction in substrate material.

FIG. 14 is a block diagram of an exemplary process of applying a microparticle coating to a substrate. The process may include applying microspheres or other expandable coatings to any of the base plate, die cut blank, container, sleeve, serving tray, double wall cup, extruded tray, soup can, and bag-in-box container. The process may include an online process 1400 and an offline process 1410. The in-line process 1400 may include a container stacking station 1420, a manufacturing station 1430, and a packaging station 1440 for manufacturing containers from paper or die cut stock. The stacking station, manufacturing station, and packaging station may be fully automated and/or include manual stations.

The coating application process may be performed in-line 1400 or off-line 1410 at the same facility or at another facility. In-line application may include applying a coating at one or more of the stacking station 1420, manufacturing station 1430, and packaging station 1440. The coating may be applied in a variety of ways including, but not limited to, brushes, sponges, printing, nozzles, sprayers, and slot coaters. Any one of these applications, or various combinations thereof, may be performed online 1400 or offline 1410, where the offline process may be performed prior to stacking stage 1420.

Application by means of a brush or brushes can be carried out by feeding the coating under pressure through a tube to the brush. The brush may be made of different materials, such as horsehair or synthetic materials. The brush may comprise hollow filaments so that the coating can be applied through the filaments. The brush may apply a pattern or design of paint. The amount of coating applied to the brush can be controlled so that the amount of coating applied to the substrate can be metered. As an illustrative and non-limiting example, the amount may be controlled to apply 1/64 inches of paint layer that can expand to 1/16 or 1/32 inches, or the distance of the gap between the inner and outer layers of the double wall cup. Preferably, the coating does not deform the shape of the outer layer after expansion. The coating may be distributed in a uniform pattern or a varying pattern. The brush can be used for more applications, such as coating the inside of bag-in-box containers.

Application with a printer may be performed by running the substrate through rollers. The substrate may be a paper stock in roll or web form, or alternatively in sheet form. The coating can be applied by pressing in spots or patterns or by complete covering, depending on the embodiment.

In fig. 15, a spray nozzle 1500 may be used to apply a coating 1510 to a substrate 1520. The nozzle can dispense the coating to apply a thin, uniform layer of coating on the substrate. One or more spray nozzles may be used to form a continuous or intermittent pattern of coating. The nozzles may be arranged such that the applied coating material overlaps, is side-by-side, and/or is spaced apart by a distance. The spray can be metered to control the thickness of the coating applied. The nozzle may also be positioned to direct the coating spray to a designated location on the substrate, such as at a corner.

In fig. 16, a non-jetting nozzle 1600 may be employed to apply a stream 1610 of coating material to a substrate 1620. The flow of coating through the nozzle can be metered to apply a precise amount of coating. The nozzle may be sized to control a specified width and height of the stream 1610. The flow from the nozzle can be switched on and off to enable a particular pattern of coating to be formed on the substrate.

In slot or dip coating applications, the substrate may be moved through a slot containing the coating material. One or both sides of the substrate may pass through the slot. The thickness of the coating applied to the trough can be controlled by how long the substrate sits in the material. The temperature of the coating and substrate may be controlled to activate or deactivate the expandable coating during the coating process. A control blade may be used to scrape off excess coating. The substrate may be fed through the slot by a tape or held separately in the slot.

By any of the above application processes, and by any other process, if it is desired to expand the coating in a later process (e.g., during manufacture or at the time of consumer use), the applied coating can be dried or cured, for example, by applying or blowing cold or warm air without activating the coating. The coating may also be expanded after manufacture and before consumer use, such as at the stacking station 1440. The coating may also be expanded before or after stacking the containers.

Coated or uncoated blanks may be fed to a stacking station 1420. The coating may be applied in an on-line or off-line process. If applied on-line, the coating may be dried prior to forming the cup, sleeve, container, etc., or the cup, sleeve, container, etc., may be formed while the coating is wet. Depending on its nature, it can take several seconds to several minutes for the paint to dry. The coating may be activated during or after the in-line manufacturing process (e.g., at the consumer stage). To excite the coating in-line, any or all of Infrared (IR), air, thermal convection, or thermal conduction methods may be employed. The coating can take several seconds to several minutes to fully expand. For example, during container manufacturing, heat may be applied to expand the coating using a core material (which holds the container from the inside of the container) and/or a hoop (which holds the cup from the outside of the container). If the wet or partially dried coating contacts the core during processing, the core may be manufactured to include a non-stick material such as TEFLON to prevent sticking or transferring the coating to the core. If the activation is done on-line, a lower activation temperature is preferred. By activating the coating, the coating expands to form a reinforcing air gap. During the manufacture of the container, the coating may partially expand, and then expansion may proceed to the consumption stage.

As noted above, the use of coatings can help reduce the thickness of the substrate required to manufacture containers, sleeves, and the like, while maintaining a better rigid feel to the consumer. The coating also improves the insulation properties of the container and helps to maintain the beverage for a longer period of timeThe material or food is warm or cold (depending on the application). The substrate may be made of natural fibers, synthetic fibers or both, such as SBS (solid bleached sulfate) paperboard or boxboard. The sleeve material, such as the liner and media, may be made of 15LB/3000ft²To 100LB/3000ft²Preferably 18LB/3000ft²To 50LB/3000ft²Is made of the material of (1). The paper substrate thickness (caliper) for hot or cold cups, soup cans, extruded containers, or other non-corrugated containers may range from 9 to 24 points, preferably from 10 to 24 points, with one point equal to 1/1000 inches.

While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the invention.

Claims (13)

1. A double-walled container, comprising:

an inner wall;

an outer wall attached to the inner wall, wherein the inner wall and the outer wall form an air shroud therebetween; and

an expandable insulating material that is thermally activatable and positioned between the inner wall and the outer wall, the material comprising a combination of a binder and expandable microcoating particles and being applied to the inner wall, the outer wall, or both to form an air passage, wherein the expandable insulating material provides rigidity to the outer wall to prevent the outer wall from collapsing against the inner wall under gripping pressure without disrupting the thermal insulating action of the air jacket;

adhesive separated by an expandable insulating material, the adhesive bonding the inner wall to the outer wall;

wherein the air channel is configured to direct thermal convection.

2. The double-walled container of claim 1, wherein the micro-encapsulated particles comprise expandable microspheres.

3. The double-walled container of claim 1, wherein the expandable insulating material provides thermal insulation between the inner wall and the outer wall.

4. The double-walled container of claim 1, wherein the adhesive is a glue.

5. The double-walled container of claim 4, wherein the micro-encapsulated particles comprise expandable microspheres.

6. The double-walled container of claim 1, wherein the outer wall is comprised of a paper stock.

7. The double-walled container of claim 6, wherein the expandable insulating material allows for a reduction in weight of the papermaking stock.

8. The double-walled container of claim 1, wherein the expandable insulating material expands upon thermal temperature activation.

9. The double-walled container of claim 1, wherein the expandable insulating material is applied in a dotted pattern.

10. The double-walled container of claim 1, wherein the expandable insulating material is applied in a tape-like manner.

11. A method of making a double-walled container, comprising:

providing a first substrate to form an inner wall of a container;

providing a second substrate to form an outer wall of the container;

providing a thermally expandable insulating material comprising a combination of a binder and expandable microcoated particles;

applying said thermally expandable insulating material to said inner wall;

applying adhesive separate from the thermally expandable insulating material to the inner wall;

attaching the outer wall to the inner wall to form a double-walled container having an air shroud between the inner wall and the outer wall; and

applying heat to the double-walled container, expanding the thermally expandable insulating material by thermal activation, wherein the thermally expanded insulating material provides rigidity to the outer wall to prevent the outer wall from collapsing against the inner wall under gripping pressure without disrupting the thermal insulating action of the air jacket.

12. The method of claim 11, wherein the thermally expandable insulating material is applied in a dotted manner.

13. The method of claim 11, wherein the thermally expandable insulating material is applied in a tape-like manner.