Double-walled Paper Cup and Method of Manufacture thereof

Abstract

Provided are a double-walled paper cup and a method of manufacture thereof. The double-walled paper cup comprises an inner cup; and an outer sleeve configured to circumferentially envelop the inner cup and to be attached at a top and bottom circumferential edge thereof to the inner cup; wherein the top edge of the outer sleeve is folded inwards on itself to form a contact strip for attachment to a portion of the inner cup adjacent to a lip of the inner cup, the contact strip defining a gap between the inner cup and outer sleeve. The method of manufacturing the paper cup comprises using a cold glue process and a hot melt glue process to attach the outer sleeve and the inner cup together.

Claims

1. A double-walled paper cup comprising: an inner cup; and an outer sleeve configured to circumferentially envelop the inner cup and to be attached at top and bottom circumferential edges thereof to the inner cup; wherein the top edge of the outer sleeve is folded inwards on itself to form a contact strip for attachment to a portion of the inner cup adjacent to a lip of the inner cup, the contact strip defining a gap between the inner cup and outer sleeve.

2. The cup of claim 1, wherein the contact strip is configured to be attached to the inner cup such that the outer sleeve is separated from the inner cup by a distance of at least the thickness of the outer sleeve.

3. The cup of claim 1, wherein the contact strip is formed by folding a strip at the top edge of the outer sleeve inwards such that the strip is co-planar with the inner surface of the outer sleeve.

4. The cup of claim 1, wherein the contact strip is formed by attaching the inwardly folded top edge of the outer sleeve to an inner surface of the outer sleeve.

5. (canceled)

6. The cup of claim 1, wherein the contact strip has a thickness that is at least double the thickness of the outer sleeve.

7-14. (canceled)

15. The cup of claim 1, wherein the bottom edge of the outer sleeve is configured in the shape of a bottom curl which defines a gap between the bottom of the outer sleeve and the inner cup.

16. (canceled)

17. The cup of claim 6, wherein the contact strip and the bottom curl define a continuous gap between the inner cup and outer sleeve from the bottom to the top of the outer sleeve.

18. A method of manufacturing a double-walled paper cup, comprising: forming an inner cup; and forming an outer sleeve configured to circumferentially envelop the inner cup, comprising folding a top edge of the outer sleeve inwards on itself to form a contact strip for attachment to a portion of the inner cup adjacent to a lip of the inner cup, the contact strip defining a gap between the inner cup and outer sleeve; and attaching the outer sleeve at top and bottom circumferential edges thereof to the inner cup.

19. The method of claim 18, comprising attaching the outer sleeve to the inner cup using a cold glue process and a hot melt glue process.

20. The method of claim 19, comprising applying cold glue to the contact strip of the outer sleeve.

21-23. (canceled)

24. The method of claim 19, comprising applying one or more spots of cold glue to the contact strip.

25-26. (canceled)

27. The method of claim 19, comprising applying cold glue first and then hot melt glue to the contact strip of the outer sleeve.

28. The method of claim 27, comprising in the hot melt glue process performed after the cold gluing process, applying hot melt glue to the inner surface of the contact strip.

29. The method of claim 28, comprising applying hot melt glue to at least a portion of the inner surface of the contact strip not coated with cold glue.

30. (canceled)

31. The method of claim 28, comprising inserting the inner cup into the outer sleeve immediately after application of the hot melt glue.

32. The method of claim 18, comprising configuring the bottom edge of the outer sleeve in the shape of a bottom curl which defines a gap between the bottom of the outer sleeve and the inner cup.

33. (canceled)

34. The method of claim 32, comprising attaching the bottom curl of the outer sleeve to the bottom circumferential portion of the inner cup using hot melt glue.

35. The method of 18, comprising applying hot melt glue to the bottom circumferential portion of the inner cup.

36-39. (canceled)

40. The method of claim 18, comprising applying the hot melt glue to the bottom circumferential portion of the inner cup before inserting the inner cup into the outer sleeve.

41-45. (canceled)

46. A double-walled paper cup manufactured using the method of claim 18.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present application will now be described with reference to the accompanying drawings in which:

[0032] FIG. 1 is a side view of a conventional double-walled cup;

[0033] FIG. 2 is a side view of a another conventional double-walled cup;

[0034] FIG. 3 is a side view of a double-walled cup in accordance with an embodiment of the present disclosure;

[0035] FIG. 4 is a flow diagram illustrating a method of manufacturing a double-walled cup, in accordance with an embodiment of the present disclosure;

[0036] FIG. 5 is a flow diagram illustrating a method of manufacturing a double-walled cup, in accordance with an embodiment of the present disclosure; and

[0037] FIG. 6 is a flow diagram illustrating a more detailed method of manufacturing a double-walled cup, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

[0038] The present disclosure provides a double-walled paper cup comprising: an inner cup; and an outer sleeve configured to circumferentially envelop the inner cup and to be attached at top and bottom circumferential edges thereof to the inner cup; wherein the top edge of the outer sleeve is folded inwards on itself to form a contact strip for attachment to a portion of the inner cup adjacent to a lip of the inner cup, the contact strip defining a gap between the inner cup and outer sleeve.

[0039] As will be explained in detail below, the present disclosure achieves inproved heat insulation by defining an air gap between the inner cup and outer sleeve. This is achieved by using a fold system on the outer sleeve to define the air gap. The bottom edge of the outer sleeve may also be configured to provide a gap between the outer sleeve and the inner cup at the bottom of the cup as is known in the art. The top edge of the outer sleeve is folded inwardly on itself to define a gap between the outer sleeve and the inner cup at the top of the cup. In this manner a continuous gap is created between the inner cup and outer sleeve from the bottom to the top of the outer sleeve. The contact strip formed by folding the top edge of the outer sleeve inwardly on itself forms a sufficient area for securely attaching the outer sleeve to the inner cup. The continuous gap reduces heat transfer from the inner cup to the outer sleeve and reduces the possibility of scalding especially when boiling water is held within the cup. As will be appreciated, the top edge of the outer sleeve is the portion of the outer sleeve that is adjacent to the lip of the inner cup, and the bottom edge of the outer sleeve is the portion of the outer sleeve that is adjacent to the base of the inner cup.

[0040] An exemplary arrangement of such a double-walled paper cup in accordance with an embodiment of the present disclosure is illustrated in FIG. 3. Referring to FIG. 3, the double-walled cup comprises an outer sleeve 301 circumferentially enveloping an inner cup 300. The inner cup 300 comprises a lip 304. The double-walled cup may have a frusto-conical shape having an increasing diameter from the bottom towards the top. Each of the outer sleeve 301 and inner cup 300 may be constructed from any suitable paper or cardboard. It will be understood that the term ‘double-walled paper cup’ in the context of the present disclosure is intended to comprise any suitable paper or cardboard. The paper or cardboard may be coated with either PE (polyethylene) or PLA (polyatic acid).

[0041] A bottom curl 302 may be provided at a bottom edge of the outer sleeve 301. The bottom curl 302 acts as a spacer to create an air gap between the planar region of the outer sleeve 301 and the inner cup 300. The gap formed at the bottom of the cup between the outer sleeve 301 and inner cup 300 may be at least 3 mm in width.

[0042] In principle, use of an air gap is similar to the use of an insulating material. If an air gap is created between two layers, the air trapped between the two layers, air being a poor conductor of heat, acts as a barrier to heat transfer. Heat is transferred across an air space by a combination of conduction, convection and radiation. Heat transfer from a liquid held within the inner cup 300 to the outer sleeve 301 is primarily a result of conduction. As is known to those skilled in the art, heat transfer by conduction is inversely proportional to the width of the air gap. The width and uniformity of the air gap is a very important design parameter that governs its effectiveness by controlling the heat transfer coefficient as in the case of insulation.

[0043] It will be appreciated that a contact strip 303 is provided at the top edge of the outer sleeve 301. The contact strip 303 may be formed by folding the top edge of the outer sleeve 301 inwards on itself. That is, the top edge of the outer sleeve 301 may be folded onto an inner surface of the outer sleeve 301 to form the contact strip 303. Accordingly, it will be appreciated that the contact strip 303 has a thickness that is at least double the thickness of the outer sleeve 301. The inwardly folded top edge of the outer sleeve 301 may be attached to the inner surface of the outer sleeve 301 by adhesive such as glue or any other suitable means. In the exemplary embodiment, an approximately 5 mm portion of the top edge of the outer sleeve 301 may be folded to create the contact strip 303. The portion of the top edge of the outer sleeve 301 that is folded substantially constitutes the width of the contact strip 303. It will be understood with reference to FIG. 3 that the width of the contact strip 303 refers to the axial distance by which the top edge of the outer sleeve 301 is folded. The outer sleeve 301 is thus configured to be attached to the inner cup 300 along the contact strip 303. Such a configuration allows for the outer sleeve 301 to be attached to the inner cup 300 along the entire width of the contact strip 303. Furthermore, the contact strip 303 acts as a spacer between the outer sleeve 301 and the inner cup 300. It will be understood that the spacer is effectively the thickness of the outer sleeve 301. The spacer creates an air gap between the outer sleeve 301 and the inner cup 300 at the top of the outer sleeve 301, the air gap being substantially equal to the thickness of the outer sleeve 301. The outer sleeve 301 may have a uniform thickness. In one embodiment, the thickness of the outer sleeve 301 may be about 1 mm. Thus, the air gap formed may also be about 1 mm in width.

[0044] It will be understood that the air gap may decrease from the bottom curl 302 to the contact strip 303. Nonetheless, it is the provision of a continuous air gap between the outer sleeve 301 and the inner cup 300 that provides heat insulating properties.

[0045] Referring to FIG. 3, the contact strip 303 of the present disclosure does not affect the ability of the lip 304 to hold a lid in place. As described previously, the contact strip 303 may be formed by folding a portion or strip at the top of the outer sleeve 301 inwards such that the strip is co-planar with the inner surface of the outer sleeve 301. Therefore the outer sleeve 301 is separated from the inner cup 300 by a distance of at least the thickness of the outer sleeve 301. The thickness of the lip 304 is thus only reduced by approximately the thickness of the contact strip 303, which in one embodiment is about 1 mm. Considering that the lip 304 may have a thickness of about 5 or 6 mm, this is a minimal impact on the size and therefore functionality of the lip 304. Thus, in accordance with an embodiment of the present disclosure, the lip 304 of the double-walled cup is configured to securely hold a lid in place.

[0046] The contact strip 303 of the double-walled cup of the present invention provides a sufficiently large contact area between the outer sleeve 301 and the inner cup 300 to provide a secure attachment therebetween. Referring to FIG. 3, the contact strip 303 provides a co-planar contact area between the inner cup 300 and the outer sleeve 301. In the embodiment of the present disclosure shown in FIG. 3, the contact strip 303 provides a contact area in the form of a strip that extends around the circumference of the outer sleeve 301. In this manner, it may be observed that the total contact area between the outer sleeve 301 and the inner cup 300 may be the width of the contact strip 303 multiplied by the circumference of the contact strip 303. The width of the contact strip 303 may be approximately 5 mm or less.

[0047] Furthermore, the contact area provided by the contact strip 303 in accordance with an exemplary arrangement of the present disclosure provides ample room for attachment of the outer sleeve 301 to the inner cup 300. As previously mentioned, the margin of error for a hot melt process is generally only 3 mm. By providing a contact strip having a width of about 5 mm, sufficient tolerance is provided for an accurate cold glue process. Moreover, provision of a strip attachment means allows for a sufficient bonding area between the surface of the inner cup 300 and the outer sleeve 301 to keep the bond stable under normal use. That is, the contact area or strip is configured to ensure that a secure bond may be achieved between the outer sleeve 301 and the inner cup 300.

[0048] Any suitable attachment method or process for securely attaching the outer sleeve 301 to the inner cup 300 may be used. The double-walled paper cup of the present disclosure may be manufactured using either a hot or cold glue process. However, it has been found that a process that involves a combination of both hot and cold gluing processes provides optimal results.

[0049] Accordingly, a method of manufacturing a double-walled paper cup according to an embodiment of the present disclosure, comprises: forming an inner cup; forming an outer sleeve configured to circumferentially envelop the inner cup, comprising folding a top edge of the outer sleeve inwards on itself to form a contact strip for attachment to a portion of the inner cup adjacent to a lip of the inner cup, the contact strip defining a gap between the inner cup and outer sleeve; and attaching the outer sleeve at top and bottom circumferential edges thereof to the inner cup.

[0050] FIG. 4 is a flow diagram illustrating a method 400 of manufacturing a double-walled cup, in accordance with an embodiment of the present disclosure. Referring to FIG. 4, the method 400 includes forming an inner cup 401; forming an outer sleeve configured to circumferentially envelop the inner cup 402, comprising folding a top edge of the outer sleeve inwards on itself to form a contact strip for attachment to a portion of the inner cup adjacent to a lip of the inner cup, the contact strip defining a gap between the inner cup and outer sleeve; and attaching the outer sleeve at top and bottom circumferential edges thereof to the inner cup 403.

[0051] The inventors have found that using a two-stage gluing process involving both cold glue and hot melt glue provides optimal results in manufacturing such double-walled paper cups. Such a two stage process relies on using two gluing stations in the manufacturing process where both cold glue and hot melt processes are performed, respectfully.

[0052] The hot melt glue securely holds the outer sleeve to the inner cup during the manufacturing process and ensures a stable connection whilst manufacturing. Furthermore, the use of cold glue ensures an extremely robust connection during use of the double-walled cup, i.e., while the double-walled cup is holding a hot beverage.

[0053] FIG. 5 is a flowchart illustrating a method 500 of manufacturing a double-walled paper cup, in accordance with an embodiment of the present disclosure. The process may be used to manufacture the double-walled cup as illustrated in FIG. 3. The method of manufacturing the double-walled paper cup according to the present embodiment comprises using a cold glue process and a hot melt glue process to attach the outer sleeve and the inner cup together. The method may include applying the cold glue to the contact strip of the outer sleeve before the hot melt glue. The method may comprise inserting the inner cup into the outer sleeve so as to attach the outer sleeve and the inner cup together.

[0054] Referring to FIG. 5, the method 500 of manufacturing the double-walled paper cup of the present disclosure may include forming the outer sleeve 501, applying cold glue to the contact strip of the outer sleeve 502, applying hot melt glue to the contact strip of the outer sleeve 503, positioning the outer sleeve and the inner cup in relation to each other 504, and attaching the outer sleeve and the inner cup together 505.

[0055] The first step may involve formation of the outer sleeve 501. The outer sleeve may be formed from a printed flat or blank. Using conventional techniques known to those skilled in the art, the sleeve may be manufactured by folding or curling a blank and gluing two ends of the blank together to form an outer sleeve having a frusto-conical shape as illustrated in FIG. 3. The outer sleeve may then be transferred to a first turntable for further processing.

[0056] At the first turntable, a bottom curl may be formed at the bottom of the outer sleeve. That is, a bottom curl may be formed at the end of the outer sleeve that has the smaller diameter. As is known to those skilled in the art, the formation of a curl in the outer sleeve requires at least two stages. The next stage of the bottom curl formation involves tightening the bottom curl.

[0057] A curl may be formed in the outer sleeve by performing at least two curling stages and in addition clamping the outer sleeve in different ways during the different curling stages. The aim is to prevent the buckling of the outer sleeve wall during the curling stages such that the outer sleeve is clamped during the different curling stages in each case just below the upper rim of the cup sleeve or the already partially completed top curl. Due to this repeated clamping, the top curl may be dependably shaped without any fear of bulging or buckling of the outer sleeve.

[0058] The step of forming the outer sleeve 501 may include formation of the contact strip on the outer sleeve. Unlike the bottom curl, the contact strip may be formed in one step. The outer sleeve may be held securely just below the top of the outer sleeve to prevent buckling. A uniform strip or section of the outer sleeve may then be folded inwards as described above to form the contact strip.

[0059] After formation of the contact strip, the outer sleeve may be transferred to a second turntable and a silicone coating may be applied to the outer sleeve. The method for applying the silicone coating may be chosen as appropriate by those skilled in the art. The purpose of the silicone coating is to lubricate the paper before curling so as to prevent scraping or marking. The silicone coating also helps to form the lip as there are spinning wheels used to fold and curl lips. The silicone acts as a lubricant so the paper can be formed without damaging the surface of the print and the paper.

[0060] The next step in the formation of the double-walled paper cup is the gluing process. The gluing process may comprise the application of cold glue first 502 and then hot melt glue 503 due to the extremely short setting time of the hot melt glue. In the cold glue process, cold glue may be applied to at last a portion of the contact strip 502. A cold glue process known to those skilled in the art may be used to apply cold glue to the contact strip on the inner surface or inner circumference of the outer sleeve. The cold glue may not be applied to the entire area of the contact strip. Rather, cold glue may be applied to the contact strip of the outer sleeve so as to form at least one discontinuous portion of cold glue on the contact strip. In this regard, multiple spots of cold glue may be applied at regular intervals to the contact strip. In the hot melt glue process performed after the cold melt process, hot melt glue may be applied to at least a portion of the contact strip not covered with cold glue.

[0061] In one embodiment, a glue gun may be used to apply two spots of cold glue in total to the contact strip. The spots of cold glue may be applied directly opposite each other i.e., at 180 degrees to each other along the circumference of the outer sleeve. Two spots of hot melt glue may be subsequently applied to the contact strip at opposite sides thereof. In this manner, all four spots of glue are spaced evenly apart on the contact strip. Specifically in this example, each spot of glue may be separated by 90 degrees on the circumference of the outer sleeve. Each of the spots of cold glue may be approximately 2 mm×4 mm in size.

[0062] In this manner, a discontinuous series of cold glue portions may be formed on the contact strip 303. For example two spots of cold glue may be applied and a blank space, approximately equal to the area of the two spots, left before the application of two more spots of glue. Once the cold glue application process is completed, the contact strip may have cold glue applied to about 50% of its area. The remaining area is left with no portions of cold glue. The use of two spots of cold glue should not be considered limiting; a single spot of cold glue may be applied and a space (approximately the same size of the glued area) may be left before application of another spot of cold glue. Alternatively, cold glue may be applied to a larger continuous area of the contact strip.

[0063] After application of the cold glue to the contact strip, hot melt glue may be applied to the inner surface of the contact strip using a hot melt process 503. The hot melt glue may be applied to the remaining portions of the contact strip not covered with cold glue. In this regard, one or more spots of hot melt glue may be applied to the inner surface of the contact strip. After completion of the hot melt glue process 503, the contact strip may have glue applied to substantially all portions thereof, e.g., alternating areas of hot melt glue and cold melt glue. Each of the spots of hot melt glue may be approximately 2 mm×4 mm in size.

[0064] As mentioned above, cold glue may be applied first 502 and then hot melt glue 503 due to the extremely short setting time of hot melt glue. Specifically, due to the short drying time, the outer sleeve should be attached to the inner cup as soon as possible after application of the hot melt glue thereto. Otherwise, if the hot melt glue is applied to the contact strip first (before the cold glue), the hot melt glue may have already dried by the time the time the outer sleeve comes in contact with the inner cup. Furthermore, due to the rapid drying of the hot melt glue, it is important that the application of the hot melt glue may be the last step in the manufacturing step before the outer sleeve comes into contact with the inner cup.

[0065] In an alternative embodiment, only cold glue may be applied to the inner surface of the contact strip of the outer sleeve. That is, the cold glue process may comprise applying cold glue around at least a portion of the inner surface of the contact strip as described above. In this regard, one or more spots of cold glue may be applied to the contact strip. In another embodiment, multiple spots of cold glue may be applied at regular intervals to the contact strip. The method may alternatively comprise applying cold glue continuously along the contact strip.

[0066] The next step in the process may be positioning the outer sleeve and inner cup in relation to each other 504. The inner cup may be manufactured using a separate process and provided to the aforementioned second turntable as needed. In this regard, the inner cup may be inserted into the outer sleeve. It will be understood that due to the outer sleeve having a frusto-conical shape having an increasing diameter from the bottom towards the top, the inner cup may be effectively inserted into only one end of the outer sleeve, namely the end with the greatest diameter. Thus, the insertion of the inner cup into the outer sleeve may comprise inserting the base portion of the cup through the end of the outer sleeve with the greatest diameter until both ends of the outer sleeve fit around the inner cup. The insertion of the inner cup into the outer sleeve may comprise a downward motion. After fitting the inner cup into the outer sleeve, the outer sleeve circumferentially envelops the inner cup.

[0067] The next step in the manufacturing method comprises attaching the outer sleeve to the inner cup 505. This step may involve pressing the contact strip firmly against the outer wall of the inner cup 505. This ensures that a continuous contact is achieved at all points. A roller device may be used to achieve this. For example, pressure may be applied to the inner wall of the inner cup to oppose a corresponding force applied to the contact strip. The bottom curl of the outer sleeve may also be attached to the inner cup. In this regard, the bottom curl of the outer sleeve may be attached to the inner cup using a hot melt glue process.

[0068] As alluded to above, before the inner cup is inserted into the outer sleeve, hot melt glue may be applied to the bottom circumferential portion of the inner cup. In conventional double-walled paper cup manufacturing processes, the glue is placed on the bottom circumferential portion of the outer sleeve first before the inner cup is pushed down. At the base of the cup this has the potential to cause cosmetic problems as the glue tends to be pushed down past the bottom curl as the inner cup pushes through. To prevent this, hot melt glue may be applied to the inner cup before it is inserted into the outer sleeve. This has the effect of pushing the glue up rather than away from the visible portion of the base of the cup, preventing cosmetic damage. More specifically, one or more spots of hot melt glue may be applied to the bottom circumferential portion of the inner cup corresponding to the bottom curl of the outer sleeve. Each of the one or more spots may be approximately 2 mm×4 mm in size. The one or more spots may be applied at different positions on the bottom circumferential portion of the inner cup. In one embodiment, two spots of hot melt glue may be applied at different positions on the bottom circumferential portion of the inner cup. In an embodiment, two spots of hot melt glue may be applied at positions 180 degrees apart on the bottom circumferential portion of the inner cup. The one or more spots of hot melt glue spread upon contact with the outer sleeve.

[0069] Since the outer sleeve under downward pressure causes the bottom curl to “curl more” it does not tear apart the paper layers leaving it structurally intact. The mechanism for attaching the bottom curl of the outer sleeve to the inner cup according to the present embodiment strengthens the bond. This ensures that a strong bond is formed between the outer sleeve and inner cup. In conventional attachment mechanisms, the paper configuration is not strong enough to ensure that the outer sleeve stays glued whilst downward pressure is applied as the inner cup is pushed downward. This is because the paper simply unravels at the contact strip, tearing very easily. This is not a problem related to the glue, but is caused because the paper is made in layers and can be easily separated if pressure in the right direction is applied. According to this embodiment of the application, the application of hot melt glue on the inner cup means the paper does not unravel and the outer sleeve is secured to the inner cup no matter what downward pressure. The process of manufacture is configured so that the hot melt glue is applied to the inner cup before being inserted into the outer sleeve. In this manner, glue is prevented from reaching below the bottom curl. The hot melt glue may be applied to the inner cup before being transferred to a joining station where it is inserted into the outer sleeve. The rate of application of hot melt glue to inner cups may be 180 cups per minute. Thus, the hot melt glue does not have time to cool before being inserted into the outer sleeve.

[0070] As described above, the gluing process comprises a cold glue process and a hot melt glue process. Both cold glue and hot melt glue may be applied to the contact strip of the outer sleeve in order to attach the contact strip of the outer sleeve to the inner cup. Alternatively, only cold glue may be applied to the contact strip of the outer sleeve in order to attach the contact strip of the outer sleeve to the inner cup. That is, hot melt glue may not be applied to the contact strip at all. The bottom curl of the outer sleeve may be attached to the inner cup using a hot melt glue process as described above.

[0071] The final step in the method may be the ejection of the completed double-walled cup for further processing such as packaging, etc. As will be understood by those skilled in the art, the above method may take place on a single “double-walling” machine having two turntables. Such a machine may be configured to carry out all of the steps described above and shown in FIG. 5. Once a first outer sleeve has been transferred from the first turntable, after creation of the contact strip, a second outer sleeve may be supplied to the first turntable. In this way, a continuous and rapid method of manufacturing the double-walled cups can be ensured.

[0072] FIG. 6 is a flow diagram illustrating a more detailed method 600 of manufacturing a double-walled cup, in accordance with an embodiment of the present disclosure. Referring to FIG. 6, the process 600 comprises the outer sleeve formation 601, transfer of the outer sleeve to a first turntable for further processing 602, formation of a bottom curl 603, tightening of the bottom curl 604, creation of the contact strip 605, transfer of the outer sleeve to a second turntable 606, silicone application to the outer sleeve 607, cold glue application 608, hot melt glue application 609, attachment of inner cup and outer sleeve 610, pressing the outer wall and inner cup together 611, and ejection 612.

[0073] It should be appreciated that the gluing process involving both the application of hot and cold glue is critical to the manufacturing process. By applying cold glue and hot melt glue in this order, a rapid connection is established ensuring a continuous manufacturing process while also ensuring the long term structural integrity of the double-walled cup. Further, as described above, by application of hot melt glue to the bottom circumferential portion of the inner cup before the inner cup is inserted into the outer sleeve, the outer sleeve can be secured to the inner cup irrespective of downward pressure and glue is prevented from reaching below the bottom curl.

[0074] Furthermore, by only having to use a relatively small amount of hot melt glue, the cost of manufacturing is reduced. For example, a maximum of 50% of the area of the contact strip may have hot melt glue applied. However, in other cases, this area may be greatly reduced and the cold glue may be the main bonding agent used. In other cases as described above, hot melt glue may not be applied to the contact strip at all.

[0075] The present disclosure also provides a double-walled paper cup which is manufactured using any of the above-described processes. That is, the present disclosure provides a double-walled paper cup which is manufactured using a cold glue process and a hot melt glue process. Both cold glue and hot melt glue may be applied to a contact strip of the outer sleeve in order to attach the contact strip of the outer sleeve to the inner cup. Alternatively, only cold glue may be applied to the contact strip of the outer sleeve in order to attach the contact strip of the outer sleeve to the inner cup. That is, hot melt glue may not be applied to the contact strip at all. A bottom curl of the outer sleeve may be attached to the inner cup using a hot melt glue process as described above.

[0076] The words comprises/comprising when used in this specification are to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.