EP2128041B1

EP2128041B1 - External cladding for a double-walled beaker and a method for producing the same

Info

Publication number: EP2128041B1
Application number: EP09006369A
Authority: EP
Inventors: Uwe Messerschmid
Original assignee: PTM Packaging Tools Machinery Pte Ltd
Current assignee: PTM Packaging Tools Machinery Pte Ltd
Priority date: 2008-05-28
Filing date: 2009-05-12
Publication date: 2012-05-02
Anticipated expiration: 2029-05-12
Also published as: DE102008026984A1; EA016924B1; AT555999T; US8387857B2; PL2128041T3; EA200900596A1; US20090294456A1; EP2128041A1

Description

The invention relates to an outer casing for a double-walled cup, which is formed from a blank of a paper material and provided with an inwardly directed curl, wherein the blank is sleeve-shaped connected by an overlap of two longitudinal edges of the blank, wherein the curl at least in the region of the overlap glued on the outside of the outer jacket or is sealed.
The invention further relates to a method for producing such an outer jacket.
Outer shells of the type mentioned are used in practice in large numbers to improve the insulating properties of paper cups. By attaching the outer shell to a cup of paper material creates a double-walled insulating cup with a substantially annular cavity between the inner shell and the outer shell of the cup, which gives the cup good insulating properties. In order to ensure a sufficiently large distance between inner shell and outer shell, it is known to attach to the outer shell at least one inward curl. The curl can be designed in different ways.
In the production of the outer jacket, a flat blank made of a paper material is connected in a sleeve-shaped manner by overlapping two longitudinal edges of the blank. An inwardly directed curl is applied to the outer jacket thus formed. Subsequently, the prefabricated outer shell is pushed in the axial direction on a likewise prefabricated cup and attached thereto. This creates a double-walled cup.
When the outer shell is pushed axially onto the inner cup, it can happen that the outer casing gets hooked on the frame of the inner cup with the inward curving.
From the Japanese patent application JP 2003-312635 an outer sheath for a double-walled cup of the aforementioned type is known in which an inwardly directed curl is glued inside the outer shell. The curl is applied to the outer shell from the inside by means of a specially shaped stamp.
The invention has for its object to provide an outer sheath for a double-walled cup, which can not easily catch when pushed onto an inner cup.
The object is achieved in that the blank in the region of the overlap contains a recess, so that at the overlap a parallel to the outer shell extending portion of the curl only leads to a total thickness which corresponds approximately to three times the material thickness of the blank.
Due to the increased thickness of the outer jacket in the region of the overlap, the spring-back properties in this area are particularly great. In the case of relatively stiff paper material, the inward curl on the outer shell in the area of the overlap is not exactly shaped, but due to the rigidity of the paper material, attempts to rewind. The inner diameter of the outer shell within the curl is thereby reduced in the region of the overlap and can lead to a hooking of the outer shell to the frame of the inner cup, when the outer shell is pushed axially onto the inner cup. By gluing or sealing the curl in the region of the overlap is effectively prevented that the curl partially rises again due to the high stiffness in the overlap. A snagging of the outer shell when pushed onto the inner cup due to a too small clear inner diameter in the region of the curl can be effectively prevented.
Gluing or sealing the curl on the inside of the outer casing is particularly advantageous if the curl has a region extending parallel to the outer casing, in that the material of the curl lies flat against the inside of the outer casing.
Often an uncoated paper material is used for the outer shell, since the outer shell does not come into contact with the liquid to be filled into the cup. When using an uncoated paper material, a glue trace is applied to a longitudinal edge of the blank before the blank is connected in a sleeve shape. According to the invention, in such a case, the curl is also glued inside the outer shell. Different types of glue can be used. For example, a cold glue, a hot glue or in particular a hotmelt adhesive ("hot melt") is suitable.
For certain applications, it may also be advantageous to produce the outer sheath from a paper material having a coating, for example made of polyethylene, at least on one side. The curl can be sealed inside by heating the plastic coating inside the outer jacket. The sealing or gluing the curl can also be performed circumferentially along the entire circumference of the outer shell.
For the efficient production of the outer jacket, it is advantageous if the blank at a longitudinal edge contains a recess which comes to lie in the region of the overlap. The recess is designed so that when overlapping the two longitudinal edges of a part of the glue line is not covered. The uncovered portion of the glue line is used in the formation of the inward curl for gluing the curl in the region of the overlap inside the outer shell.
The recess of the blank in the region of the overlap is preferably designed so that the curl in an area of the overlap only leads to a total thickness of the outer shell, which corresponds approximately to three times the material thickness of the blank. In contrast to a conventional manner, at least four times the material thickness in the area of Overlapping also reduces the reduced total thickness in the overlap area, the risk of entanglement of the outer shell when pushed onto the inner cup.
An inventive outer jacket is particularly suitable for cups that have a substantially frusto-conical shape. The outer sheath can accordingly also be conical. The glued on the outer shell or sealed Einrollung is attached to the end of the outer shell, which has the smaller circumference. However, an outer sheath according to the invention is not only suitable for cups made of paper material, but can also be used very advantageously as an outer sheath for cups of plastic material.
Furthermore, an outer sheath according to the invention is particularly suitable for an inner cup which has a widening on its frame, wherein a lower edge of the widening forms a standing surface for the cup. In Innenbechem with expanded frame pushing on an outer sheath is particularly critical, since the widening enclosing diameter may be the same size or even slightly larger than the inner diameter of the curl of the outer sheath. Even with such inner cups can be effectively prevented with an outer jacket according to the invention snagging of the outer shell during axial pushing.
Further advantages and features of the invention will become apparent from the claims and the following description of some embodiments in conjunction with the figures. Individual features of the different embodiments shown and described can be combined in any way, without exceeding the scope of the invention.
Show it:

FIG. 1 an outer jacket according to the invention for a double-walled cup in longitudinal section,
FIG. 2 a plan view in the direction of arrow II of FIG. 1 on the outer jacket,
FIG. 3 a flat blank for an outer jacket of FIG. 1 .
FIG. 4 a partially illustrated longitudinal section of a double-walled cup with an outer shell of FIG. 1 .
FIG. 5 a view similar FIG. 4 on a variant of a double-walled cup.

In the Figures 1 and 2 an outer jacket 1 for a double-walled cup 2 is shown. The double-walled cup 2 is below with the help of FIG. 5 described in more detail. The outer shell 1 is made of a paper material and has a sleeve-shaped, conical shape. At the end with the smaller circumference, an inwardly directed curl 3 is attached.
The outer shell 1 is formed from a blank 4 of paper material. The flat blank 4 as starting material for the outer jacket 1 is in FIG. 3 shown. The blank 4 has substantially the shape of a segment of a circular ring. The blank has two longitudinal edges 5 and 6, which are connected to form an overlap 7 with each other, so that the sleeve-shaped outer shell 1 is formed. To join the longitudinal edges 5 and 6 in the region of the overlap 7, a glue trace 8 is applied to the flat blank 4 at the longitudinal edge 6. The glue trace 8 is applied to the side of the blank 4, which subsequently forms the inside 9 of the outer shell 1. The flat blank 4 is wound after applying the glue trace 8 around a conical dome, not shown. When winding the blank 4 on the mandrel, the longitudinal edge 6 with the glue trace 8 on the longitudinal edge. 5 placed and pressed so that the overlap 7 arises. Subsequently, the curl 3 is formed by an unillustrated mold. The circular edge 10 of the outer shell 1 is folded inwards by the parallel to the central axis 11 of the outer shell 1 supplied mold and applied to the inside 9.
According to the invention, the curl 3 is glued in the region of the overlap 7 on the inside 9. For this purpose, a recess 12 is provided on the blank 4 at the longitudinal edge 5, which comes to lie in the region of the overlap 7. The recess 12 is in FIG. 3 recognizable. The recess 12 is designed so that it comes close to the fold line 13 for the curl 3. The glue trace 8 on the longitudinal edge 6 is applied beyond the fold line 13 to the area of the blank 4, which subsequently forms the curl 3. Through the recess 12, a portion 14 of the glue trace is not covered in forming the overlap 7 of the two longitudinal edges 5 and 6. The uncovered part 14 of the glue track 8 is located in the region of the blank 4, which subsequently forms a region 15 of the curl 3 running parallel to the outer casing 1. The uncovered portion 14 of the glue line 8 is located between the fold line 13 for the curl 3 and the edge 10. In the formation of the inward curl 3, as in FIG. 1 is shown, now comes the uncovered part 14 of the glue track 8 against the inside 9 of the outer shell 1 and thereby glue the curl 3 in the region of the overlap 7 inside the outer shell 1 at.
The recess 12 has the advantage that the gluing of the curl 3 on the inside 9 of the outer shell 1 can be realized without additional operation and without additional glue application. In addition, the recess 12 has the advantage that the curl 3 in the region of the overlap 7 only has a total thickness which corresponds approximately to three times the material thickness of the blank. The curl 3 is thus hardly thicker in the region of the overlap 7 than in the remaining region of the circumference of the edge 10. It ensures a practically constant large inner diameter C in the region of the curl 3.
In FIG. 4 a double-walled cup 2 is shown, which has an outer casing 1 according to the invention. The outer jacket 1 is attached to a prefabricated inner cup 16. The inner cup 16 consists essentially of a conical shell 17, which is referred to as the inner shell with respect to the double-walled cup 2, and a cup-shaped bottom 18. The open side of the cup-shaped bottom 18 is arranged so that it from the filling opening of the cup 2 facing away. The bottom 3 is connected with its wall in the region of the smaller circumference of the shell 17 liquid-tight with this by forming a frame 19. in the Area of the frame 19, the material of the shell 17 is wrapped around the wall of the bottom 3 and turned inwards. The jacket 17 and the bottom 18 form a fillable interior 20 of the cup 2. The jacket 20 delimiting the interior 20 has at its upper edge, that is to say in the region of the larger circumference, an outwardly beaded mouth roll 21 which surrounds the filling opening. The inner cup 16 preferably has a round cross section and thus a substantially truncated cone-like shape.
The frame 19 has an outwardly projecting widening 22 at least in one area along its circumference. By widening is to be understood that the frame 19 is issued relative to a circular cylinder about the central axis of the inner cup 16 to the outside, so that the frame 19 includes a downwardly, to the standing surface expanding cross-sectional area. A lower edge 23 of the expansion 22 on the frame 19 forms the base for the cup 2. The cup 2 is in use on its footprint, which is increased by the expansion 22. As a result, tipping over the cup 2 is difficult. The widening 22 is preferably designed circumferentially along the circumference of the frame 19. The widening 22 enclosing outer diameter is referred to as diameter A.
It can be provided that the jacket 20 delimiting the interior 20 contains a rib or bead 24 which can absorb forces acting in the direction of the center axis of the cup 2, that is to say forces acting when stacking between two cups. A diameter B in the region of the bead 24 is matched to the diameter A of the expansion 22 on the frame 19, so that the lower edge 23 of a first cup 2 can be supported on the bead 24 of a second cup 2 and a stable stacking of several similar cup 2 is guaranteed. Even when stacking very high forces occur in the direction of the central axis of the cup 2, there is no wedging of two cups into one another, so that an easy removability of the cup 2 is ensured during unstacking.
So that the outer casing 1 does not affect the stacking properties of the double-walled cup 2, it is provided that the outer contour of the outer casing 1 is within a parallelism 25 to the inner casing 17, wherein the parallel 25 is applied to the widening 22 of the frame 19.
The inner shell 17 has in the region of the mouth roll 21 a sudden change in size form a shoulder 26, which is seen from the bottom 18 to the mouth roll 21 as a sudden cross-sectional widening. By the shoulder 26 is formed between the inner shell 17th and the outer shell 1, a substantially annular cavity 27, which lends the double-walled cup 2 a very good thermal insulation. The outer casing 1 is located in the region between the mouth roll 21 and the shoulder 26 on the inner shell 17 and can be fixed there, for example by sealing or gluing. The attached at the bottom of the outer shell 1 curl 3 is with its smallest diameter C on the inner cup 16 at.
It is provided that the smallest diameter C of the curl 3 is smaller than the diameter A of the widening 22 on the frame 19. In the production of the double-walled cup 2 of the prefabricated outer shell is pushed over a likewise completely prefabricated inner cup 16 from below in the axial direction. The paper material of the inner cup 16 and the paper material of the outer shell 1 are elastic enough that the outer shell 1 can be pushed without damage with its smallest diameter C on the curl 3 over the diameter A of the expansion 22 over.
Thus, the curl 3 of the outer shell 1 is not entangled at the lower edge 32 of the expansion 22 on the frame 19, the parallel to the outer shell 1 extending portion 15 of the curl 3 is provided. The diameter at the upper edge of the curl 3 is denoted by the reference numeral D and is greater than the diameter A at the widening 22. It is also provided according to the invention that the curl 3 glued in the region of the overlap 7 on the inside 9 of the outer shell 1 is. By gluing the curl 3 in the region of the overlap 7 prevents the curl 3 by the high stiffness in the region of the overlap 7 again easily rolls up and the region 15 of the curl 3 is not tight against the inside 9.
Due to the glued in the region of the overlap 7 curl 3 3 hooking of the outer shell 1 during axial sliding on the inner cup 16 is effectively prevented and the production speed in the production of the double-walled cup 2 can be increased.
In FIG. 5 is a variant of a double-walled Isolierbechers 2 of FIG. 4 shown. Like reference numerals denote like parts of the cup 2, so that a repeated description can be dispensed with. The inner cup 16 of FIG. 5 has no shoulder 26 below the mouth roll 21. To ensure a sufficiently wide cavity 27 between inner shell 17 and outer shell 1, an inwardly directed curl 28 is provided at the upper edge of the outer shell 1, which is supported on the inner shell 17. The curl 3 at the bottom of the outer shell 1 in turn has a parallel to
Outer jacket 1 extending region 15 and is thus in the range of- in FIG. 5 Not shown - overlap 7 glued on the inside 9. In modification to the in the FIGS. 1 and 4 shown curl 3 is the curl 3 after FIG. 5 not flattened below the region 15, but instead rolled up with an increased radius of curvature. The design of the curl 3 is advantageously adapted to the rigidity and thickness of the paper material used for the outer shell 1.

Claims

Outer jacket (1) for a double-walled cup (2) formed from a piece (4) cut from a paper material and with an inward-facing rolled lip (3) whereby two longitudinal edges (5, 6) of the cut piece (4) are overlapped (7) to join the cut piece (4) into a sleeve, whereby the rolled lip (3) is glued or sealed to the inner face (9) of the outer jacket (1) at least in the area of the overlap (7), characterised in that the cut piece (4) has a notch (12) in the region of the overlap (7), so that an area (15) of the rolled lip (3) that runs parallel to the outer jacket (1) at the overlap (7) only results in a total thickness that corresponds to three times the thickness of the material of the cut piece (4).
Method for the manufacture of an outer jacket for a double-walled cup in which a flat piece cut out of a paper material is joined to form a sleeve by overlapping two longitudinal edges of the cut piece, and in which the outer jacket formed in this way is given an inwardly-facing rolled lip, whereby the rolled lip is glued or sealed to the outer jacket in the region of the overlap, characterised in that the cut piece incorporates a notch at a longitudinal edge in the region that forms the rolled lip and which comes to lie in the area of the overlap, so that an area of the rolled lip that runs parallel to the outer jacket at the overlap only results in a total thickness that corresponds to three times the thickness of the material of the cut piece.
Method according to Claim 2, characterised in that a track of glue is applied to the other longitudinal edge of the cut piece, before the cut piece is joined to form a sleeve.
Method according to Claim 3, characterised in that when the two longitudinal edges are overlapped, the notch leaves a part of the glue track uncovered.
Method according to Claim 4, characterised in that when forming the inward-facing rolled lip, the uncovered part of the glue track glues the rolled lip in the region of the overlap on the inside to the outer jacket.