METHOD FOR AT LEAST PARTIALLY CLOSING THE MAIN OPENING OF A DRINKING STRAW

Description

[0001] Drinking straws for sipping and drinking liquids have long been known in various designs. In a basic form, they consist of an elongated tube open at both ends, with one end immersed in the liquid to be consumed and the other end placed in the mouth by the consumer.

[0002] US patent 2014 / 0263718 A1 discloses a drinking straw with a tongue-shaped section at one end, designed to remove food particles from between the teeth of a consumer. Until needed, the tongue-shaped section can be loosely inserted into the opening of the straw, allowing liquid to be drawn freely from the bottom of a drinking vessel.

[0003] More recently, variations have emerged in which the opening at the end of the straw that the consumer puts in their mouth is closed, and instead, several small holes, for example four, are provided at the upper end of the straw in the area of ​​the wall. The liquid is drawn in through these holes and enters the consumer's mouth. Such straws are also known as "sensory straws." The beverage emerging from several small openings creates a different and often more pleasant drinking experience, as the liquid does not flow out of the main opening in a single stream, but is directed simultaneously through the small holes into different areas of the mouth. In the context of the invention, "closing the end of a straw" refers to at least partially closing the main opening of the straw.

[0004] The end of drinking straws made from thermoplastic materials such as polyethylene or polypropylene is sealed simply by welding using heat and pressure. The outlet openings are then created by drilling or punching small holes into the straw's wall.

[0005] A growing global awareness of environmental issues and sustainability has led to political and economic regulations in recent years stipulating that plastic packaging should be reduced in the future and, in particular, single-use plastic items should be avoided as much as possible. In this context, drinking straws are also increasingly being made from other, preferably biodegradable, materials. For example, drinking straws made from paper or sugar cane already exist.

[0006] To create a "sensory straw" from paper, different techniques are required to seal the end opening compared to plastic straws. Instead of welding, the end of the straw is glued. This involves applying a small amount of adhesive to one end of the straw and positioning it precisely. This area is then compressed so that the straw walls bond together, sealing the opening. Similar to a plastic straw, small holes are then drilled or punched into the wall to allow the straw to dispense. The challenge with this method lies in precisely positioning a defined, small amount of adhesive inside the hollow straw. This is technically complex and therefore comparatively time-consuming and expensive.

[0007] The present invention therefore aims to provide a method for at least partially closing a main opening of a paper-based drinking straw, which is technically simpler and therefore faster and more cost-effective than known methods.

[0008] This problem is solved by a method having the features of claim 1.

[0009] Advantageous embodiments and further developments of the invention are the subject of the dependent claims.

[0010] According to claim 1, the invention is a method for at least partially closing a main opening of a paper-based drinking straw, comprising the following steps: Provide a paper-based, tube-shaped drinking straw; cut off one end of the straw to form a tongue-shaped section; fold the tongue-shaped section over the opening of the straw to create two side openings; glue the tongue-shaped section to the outside of the straw wall.

[0011] In other words, the inventive method provides that a tab-like, tongue-shaped section is formed in an end region of the drinking straw by appropriate cutting. This section is folded over the opening of the drinking straw and glued to the outside of the straw wall. The adhesive required for bonding can be applied either to the outside of the straw wall or in the area of ​​the tongue-shaped section. In both cases, it is not necessary to introduce the adhesive into the tubular hollow body. Such bonding on the outside of the straw wall is significantly simpler from a process engineering perspective and can be carried out more efficiently and therefore more cost-effectively.

[0012] The invention provides that the tongue-shaped section is folded over and glued to the outer wall of the drinking straw in such a way that two lateral openings are formed. In other words, the tongue-shaped section is folded over only to the extent that two opposing openings remain on the sides. In this position, the tongue-shaped section is glued to the outer wall of the drinking straw. During use, liquid can be drawn in through these lateral openings and enter the consumer's mouth. The size of these openings can be adjusted within certain limits by varying the degree of overlap between the tongue-shaped section and the wall of the drinking straw.

[0013] The process of folding the tongue-shaped section over the opening of the drinking straw can be facilitated by using a mandrel. This is a round rod with a diameter adapted to the desired size of the side openings. By wrapping the tongue-shaped section circumferentially around the mandrel, it is particularly easy to impose a uniform curve on the tongue-shaped section and to neatly form the rounded end of the drinking straw. The size of the side openings can be influenced by selecting mandrells of different diameters.

[0014] The method according to the invention is therefore not only characterized by the fact that it is simplified by the application of adhesive to the outside, but also has the advantage that two small lateral openings are already formed directly during the folding over and gluing of the drinking straw at the end and do not have to be introduced separately in a subsequent process step.

[0015] However, according to the invention, it can be provided that, in addition to the two lateral openings, further small holes are introduced into the wall of the drinking straw, for example by drilling or punching. Preferably, two further diametrically opposed holes can be introduced in a single drilling or punching operation by driving a suitable tool completely through the tubular drinking straw in a direction perpendicular to its longitudinal axis. A particularly pleasant drinking experience is achieved if the lateral openings and the additional holes are arranged essentially evenly distributed around the circumference of the drinking straw.

[0016] According to one embodiment of the inventive method, a fast-setting hot melt adhesive suitable for food contact is used to bond the tongue-shaped section to the outer surface of the drinking straw wall. This could, for example, be the adhesive known as… Technomelt Supra PRO 220 Plus The product in question is the well-known polyolefin hot melt adhesive from Henkel. Other suitable hot melt adhesives can also be used. A fast-setting hot melt adhesive has the advantage that the bond between the tongue-shaped section and the wall of the drinking straw holds reliably after only brief pressure. Furthermore, such adhesives are generally low-migration and therefore particularly suitable for food contact. The adhesive can be applied in a conventional manner, for example, using a nozzle or a disc.

[0017] According to one embodiment of the inventive method, the end region of the drinking straw is cut by making two first cuts along two first cutting lines starting from an end edge of the drinking straw into the wall of the drinking straw and a second cut along a second cutting line, wherein the second cut is made in a direction parallel to the end edge of the drinking straw and the cutting line connects the endpoints of the two first cutting lines.

[0018] Preferably, the first two cuts are made simultaneously in a single cutting operation using a cutting tool that is attached to a point on the end edge and inserted into the wall of the drinking straw at an angle to the longitudinal direction of the drinking straw.

[0019] The end of the drinking straw can be trimmed, for example, by first making two cuts along two lines, approximately 1 to 3 cm long, in a single operation using a knife held at an angle at one point on the end. A second cut, connecting the endpoints of the first two lines and parallel to the end, removes a section from the straw wall, creating a tongue-shaped section that protrudes beyond the opening.

[0020] The contour of the tongue-shaped section can, in principle, be further trimmed as desired. However, by precisely positioning a cutting tool at a point on the end edge of the drinking straw and inserting the cutting tool into the wall at an angle to the longitudinal direction of the drinking straw, a tongue-shaped section is automatically created, which tapers towards its free end and is rounded at that free end.

[0021] A particularly favorable contour of the tongue-shaped section is achieved when the two initial cuts are made at an angle of approximately 5° to 35°, preferably approximately 10° to 20°, relative to the longitudinal direction of the drinking straw. For example, the cuts can be made at an angle of approximately 15° relative to the longitudinal direction of the straw. For this purpose, the cutting tool can be positioned at a point on the end edge and inserted into the straw wall at the desired angle relative to its longitudinal direction over a length of approximately 1 to 3 cm, thus creating two cuts simultaneously.

[0022] The second cut, connecting the two first cut lines at their endpoints, is made in a direction parallel to the edge of the drinking straw and perpendicular to its longitudinal direction. The cutting depth of this second cut into the drinking straw is preferably about half to two-thirds of the straw's diameter. A particularly favorable contour of the tongue-shaped section is achieved when the second cut has a cutting depth of about three-fifths of the straw's diameter.

[0023] The first two cuts and the second cut can be performed either simultaneously or sequentially. In particular, a first cutting tool can be used to perform the first cuts and a second cutting tool can be used to perform the second cut.

[0024] In principle, the size of the resulting lateral openings can be influenced by the specific design of the outer contour of the tongue-shaped section as well as by the extent of the overlap of the folded tongue-shaped section with the wall of the drinking straw.

[0025] According to one embodiment of the inventive method, the tongue-shaped section is rounded at its free end. This ensures that the free end can be securely bonded to the outer surface of the wall without any protruding corners.

[0026] The invention provides a method for manufacturing paper-based drinking straws that are at least partially closed at a main opening, by which such drinking straws can be manufactured very efficiently in large quantities.

[0027] The invention will now be explained in more detail using an exemplary embodiment and with reference to the accompanying figures. These show: Figure 1: a section of a paper-based drinking straw in a side, slightly oblique view; Figure 2: the drinking straw made of Figure 1 , where an area to be cut is marked; Figure 3: the drinking straw made of Figure 1 after cutting in side view; Figure 4: the cut drinking straw made of Figure 3 in a view rotated 90° around the longitudinal axis; Figure 5: the drinking straw made of Figure 4 , wherein the tongue-shaped section was folded over the opening of the drinking straw and glued to the outside of the wall of the drinking straw; Figure 6: the drinking straw made of Figure 5 in a view rotated 90° around the longitudinal axis.

[0028] The Figures 1 to 6The figures show a section of a paper-based drinking straw 1 during the individual process steps of the inventive method. The illustrations are schematic only and not necessarily to scale.

[0029] Figure 1 Figure 1 shows the end region of the drinking straw 1 as it is prepared for the process in a first step. The drinking straw 1 is designed as a tubular hollow body with a wall 2 and openings at the ends, as shown in the illustration. Figure 1 Only an end opening 3 is shown. The drinking straw 1 is made of paper.

[0030] In a subsequent process step, the end section of the drinking straw 1 is cut to form a tongue-shaped section 4. Figure 2 The area to be removed by cutting is shown hatched (7). Specifically, the cutting is initially carried out along two first cutting lines 5, of which in the Figure 2Only the cutting line 5 facing the viewer is visible. The cutting lines 5 begin at the end edge 8 of the drinking straw 1 and extend from there at a slight angle of approximately 15° to the longitudinal direction L of the drinking straw through the wall 2 of the drinking straw 1. The first two cuts along the first cutting lines 5 are made simultaneously in a single cutting operation by a cutting tool positioned at the end edge 8 of the drinking straw 1. At a distance d of approximately 1.5 cm from the end edge 8, the first cutting lines 5 end or transition into a second cutting line 6, which extends essentially parallel to the end edge 8 and connects the ends of the two first cutting lines 5. The cutting depth of the second cut along the second cutting line 6 is approximately 3 / 5 of the diameter of the drinking straw. By cutting along the cutting lines 5 and 6, the Figure 2 The hatched area 7 is to be removed from the wall 2 of the drinking straw 1. A new opening 3a of the drinking straw 1 is created adjacent to the second cutting line 6.

[0031] Figure 3 Figure 1 shows a drinking straw cut in this way in a side view. Figure 4 Figure 1 shows the same drinking straw 1 after a 90° rotation about its longitudinal axis in the direction indicated by the rotation arrow D. The protruding, tongue-shaped section 4, which is rounded at its free end 11, is clearly visible.

[0032] The tongue-shaped section 4 is formed in a subsequent process step according to arrow P in Figure 4 folded over opening 3a and glued to the outer surface of wall 2 of the drinking straw 1. For this purpose, the outer surface 2 of the wall of the drinking straw 1 is coated in the Figure 4A fast-setting, food-safe hot melt adhesive is applied to the area designated 9. The hot melt adhesive bonds the tongue-shaped section 4 to the outer surface of the wall 2 of the drinking straw 1, so that the opening 3a is substantially closed, cf. Figure 5 . However, the overlap of the tongue-shaped section 4 with the wall 2 of the drinking straw 1 is chosen during folding and gluing such that two lateral openings 10 are formed, which are particularly evident from the illustration of the Figure 6 are evident. Figure 6 shows the drinking straw 1 again in the same orientation as in Figure 3 , i.e., compared to the representations in the Figures 4 and 5 rotated back 90° around the longitudinal axis.

[0033] The size of the openings 10 can be scaled by the degree of overlap between the tongue-shaped section 4 and the wall 2 of the drinking straw 1, i.e. the openings 10 become smaller the further the tongue-shaped section 4 is placed over the wall 2.

[0034] For a pleasant drinking experience, it may be sufficient if the liquid drawn in through the straw 1 exits from the two opposing openings 10 and is thus directed into different areas of the consumer's mouth. However, in an alternative embodiment of the method according to the invention, it may also be provided that, in addition to the two lateral openings 10, further small holes, not shown in the figures, are introduced into the wall 2 of the straw 1 as outlet openings. These can be introduced into the wall 2, for example, by drilling or punching. By driving a suitable tool completely through the straw 1 in a direction perpendicular to its longitudinal axis, two further diametrically opposed holes can be introduced into the wall 2 in a single drilling or punching operation.These additional holes penetrate the wall 2 of the drinking straw 1 and, depending on the arrangement, also the area of ​​the tongue-shaped section 4 that overlaps with the wall 2.

Claims

1. A method for at least partially sealing a main opening of a paper-based drinking straw (1), comprising the following steps: - providing a tubular paper-based drinking straw (1); - cutting an end region of the drinking straw (1) so that a tongue-shaped portion (4) is formed; - folding the tongue-shaped portion (4) over the opening (3a) of the drinking straw (1) so that two lateral openings (10) are formed; - adhesively bonding the tongue-shaped portion (4) to the outer side of the wall (2) of the drinking straw (1).

2. The method according to claim 1, characterized in that, for bonding the tongue-shaped portion (4) to the outer side of the wall (2) of the drinking straw (1), a defined amount of adhesive is applied to the outer side of the wall (2) of the drinking straw (1).

3. The method according to claim 1 or 2, characterized in that, in addition to the two lateral openings, at least one hole is made in the wall (2) of the drinking straw (1).

4. The method according to claim 3, characterized in that, in addition to the two lateral openings, two diametrically opposite holes are made in the wall (2) of the drinking straw (1).

5. The method according to one of claims 1 to 4, characterized in that the end region of the drinking straw (1) is cut by making two first cuts, along two first cut lines (5) starting from an end edge (8) of the drinking straw (1), into the wall (2) of the drinking straw (1) and making a second cut along a second cut line (6), the second cut being made in a direction parallel to the end edge (8) of the drinking straw (1) and the cutting line (6) connecting the end points of the two first cutting lines (5).

6. The method according to claim 5, characterized in that the two first cuts are formed simultaneously in a single cutting operation with the aid of a cutting tool which is positioned at a point on the end edge (8) and is inserted into the wall (2) of the drinking straw (1) at an angle with respect to the longitudinal direction (L) of the drinking straw.

7. The method according to claim 6, characterized in that the angle with respect to the longitudinal direction (L) is 5° to 35°, preferably 10° to 20°, particularly preferably approximately 15°.

8. The method according to one of claims 5 to 7, characterized in that the cutting depth of the second cut into the drinking straw (1) is half to 2 / 3, preferably approximately 3 / 5, of the diameter of the drinking straw (1).

9. The method according to one of claims 1 to 8, characterized in that the tongue-shaped portion (4) is rounded at its free end (11).

10. The method according to one of claims 1 to 9, characterized in that a fast-setting hot-melt adhesive suitable for food contact is used for bonding the tongue-shaped portion (4) to the outer side of the wall (2) of the drinking straw (1).