EXTRUSION-BLOW-MOULDED CONTAINER WITH A SCREW CAP

Abstract

A container with a screw cap is produced from a plastics material, by blow molding, and has a body with a first end and a second end, which is located opposite the first end, and with a lateral surface located therebetween, wherein a base with a standing surface is formed at the second end and an opening is formed at the first end, and wherein the opening is defined by a neck, which encloses the opening and is formed in one piece with the container, an external thread being formed on the neck, wherein the screw cap is provided with an internal thread which, when the screw cap has been placed in position, interacts with the external thread, and wherein a sealing element is formed on the inner side of the screw cap.

Claims

1.-19. (canceled)

20. Container with a screw cap, wherein the container is produced from a plastics material, in particular by blow molding, and has a body with a first end and a second end, which is located substantially opposite the first end, and with a lateral surface located therebetween, wherein a base with a standing surface is formed at the second end and an opening is formed at the first end, and wherein the opening is defined by a neck, which encloses the opening and is formed in one piece with the container, and an external thread is formed on the neck, wherein the screw cap is provided with an internal thread which, when the screw cap has been placed in position, interacts with the external thread, and wherein a sealing element is formed on the inner side of the screw cap and, when the latter has been placed in position, projects into the opening, and wherein the external thread attains its final rigidity by being screw-connected to the screw cap.

21. The container with a screw cap according to claim 20, wherein the sealing effect between the sealing element and the neck is realized in that the neck is widened when the sealing element projects into the neck.

22. The container with a screw cap according to claim 20, wherein the wall thickness of the screw cap is greater than the wall thickness of the container.

23. The container with a screw cap according to claim 20, wherein the container has a wall thickness of 0.2-0.4 mm.

24. The container with a screw cap according to claim 20, wherein the screw cap has a wall thickness of 0.7-1 mm.

25. The container with a screw cap according to claim 20, wherein the wall thickness of the neck decreases in the direction of its open edge.

26. The container with a screw cap according to claim 20, wherein the screw cap has a projection to which a tool can be applied, and a torque can be transmitted from the tool to the cap.

27. The container with a screw cap according to claim 26, wherein the projection is a depression which acts as the sealing element.

28. The container with a screw cap according to claim 20, wherein the container serves to refill filling material into an existing container and can be folded to a filling volume close to zero after emptying.

29. The container with a screw cap according to claim 20, wherein the container is free of a further opening.

30. The container with a screw cap according to claim 20, wherein a first and a second shoulder adjoin the neck.

31. The container with a screw cap according to claim 20, wherein the first and second shoulders transition into the lateral surface of the container.

32. The container with a screw cap according to claim 20, wherein the opening is formed in such a way that it is within the outline of the base in a plan view of the container.

33. The container with a screw cap according to claim 20, wherein the opening is located centrally within the outline of the base.

34. The container with a screw cap according to claim 20, wherein the base has a main axis and a secondary axis, and the opening is located off-center on the main axis.

35. The container with a screw cap according to claim 20, wherein the first shoulder has a convex shape starting from the neck.

36. The container with a screw cap according to claim 20, wherein the first and second shoulders have a concave shape starting from the neck and run out into the lateral surface in a convex shape.

37. The container with a screw cap according to claim 20, wherein the neck is blow-molded together with the container.

38. The container with a screw cap according to claim 20, wherein the container is made of HDPE, wherein the proportion of recycled HDPE is between 10 and 100 wt. %.

Description

[0028] Further advantages and features become apparent from the following description of several exemplary embodiments of the invention with reference to the schematic representations. In the figures, in a representation that is not to scale:

[0029] FIG. 1: is a perspectival view of an extrusion blow-molded container with a neck formed from the container, enclosing an opening, in a first embodiment;

[0030] FIG. 2: is a side view of the container from FIG. 1;

[0031] FIG. 3: is a plan view of the container from FIG. 1;

[0032] FIG. 4: is a bottom view of the container from FIG. 1;

[0033] FIG. 5: is a perspectival view of the extrusion blow-molded container with a neck formed from the container, enclosing an opening, in a second embodiment;

[0034] FIG. 6: is a side view of the container from FIG. 5;

[0035] FIG. 7: is a plan view of the container from FIG. 5;

[0036] FIG. 8: is a bottom view of the container from FIG. 5;

[0037] FIG. 9: shows the first embodiment of the container with a screwed-on cap;

[0038] FIG. 10: shows the second embodiment of the container with a screwed-on cap;

[0039] FIG. 11: is a cross-section through the container neck and the screw cap screwed onto the neck;

[0040] FIG. 12: is a perspectival sectional view through the container neck and the screw cap screwed onto the neck; and

[0041] FIG. 13: is a perspectival view of the screw cap.

[0042] FIGS. 1 to 4 and 9, or 5 and 8 to 10, show possible embodiments of a container that is produced from a plastics material by extrusion blow molding and is designated overall by reference sign 11. The container 11 is intended in particular as a so-called refill container. This means that it is as lightweight as possible and is stabilized by the filling material when it is full. Nevertheless, it has sufficient inherent stability to permanently maintain its container shape.

[0043] After the filling material has been completely transferred into an existing container, the refill container 11 can be folded up so small, due to its relatively low inherent stability, that its filling volume is almost zero. This approach is extremely sustainable, especially if the container is made from recycled plastics material. The container can be made of polyethylene or polypropylene.

[0044] The container 11 has a body 13 that has a first end 15 and a second end 17 that is substantially opposite the first end 15. The second end 17 is closed in a fluid-tight manner and is designed as a base 19 on which a standing surface 21 is formed.

[0045] An opening 23 is blow-molded together with the remaining container 11, at the first end, and is therefore simultaneously formed with the container 11 in the blow mold by inflating the container material. Preferably, the container 11 is free of any further opening. As a result, the blow mold can be designed simply, the container 11 requires less material for its production, and the opening can be closed by a screw cap 37 after filling. Compared to the variant with two necks, the welding process on the filling line is eliminated here. As a result, no welding system needs to be installed on the filling line, making the filling system more cost-effective to purchase and operate.

[0046] The opening 23 is defined by a neck 25 which surrounds the opening 23 and which the first and second shoulders 27, 29 adjoin. The shoulders 27, 29 merge seamlessly into the lateral surface 30 of the container 11.

[0047] In a particularly advantageous embodiment, the opening 23 is located within the mold separation and within the outline of the base 19 (FIG. 3 and FIG. 7). This ensures that sufficient material is present for the formation of an external thread 31 on the neck 25.

[0048] FIGS. 3 and 7 show that the base 19 of the container can have a main axis 33 and a secondary axis 35. The opening 23 or the neck 25 are located on the main axis, such that the requirement described in the last paragraph is met.

[0049] In the first exemplary embodiment according to FIG. 1 to 4, the opening 23 is arranged off-center on the main axis 33 in the plan view. In the second exemplary embodiment according to FIG. 5 to 8, the opening is arranged centrally on the main axis.

[0050] In the first embodiment, the first shoulder 27 extends in a convex manner starting from the neck 25, whereas the second shoulder 29 has a concave shape from the neck and runs out in the lateral surface in a convex shape. This places the neck 25 in a convenient position to allow filling material to be transferred into another container without spilling.

[0051] In the second embodiment, the first and second shoulders 27, 29 have a concave shape starting from the neck 25 and run out into the lateral surface 30 in a convex shape.

[0052] The external thread 31 has been developed specifically for the use of lightweight packagings, in particular refill containers. It can be formed with very little material and only attains its final stiffness through the screw connection with the screw cap 37, since it is compressed by the attached screw cap 37.

[0053] The screw cap 37 has a sealing element 39 and an internal thread 41, which projects into the opening 23 when the screw cap is attached to the neck 25. In addition, the screw cap has an internal thread 41, which interacts with the external thread 31. The sealing element 39 is designed to be rigid in such a way that it can widen the thin-walled neck 25. This results in the sealing effect between the neck 25 and the screw cap 37. The rigidity of the screw cap 37 and consequently of the sealing element 39 and the internal thread 41 is achieved by the screw cap 37 having a wall thickness of, for example, 0.8 mm.

[0054] FIGS. 11 and 12 show the open edge 42 of the neck, the wall thickness of which is reduced. The reduction can be achieved via a step 44. The wall thickness of the open edge is preferably 0.2 mm, wherein the wall thickness of the container is between 0.2 mm and 0.4 mm. Due to this particularly low wall thickness, the neck is flexible and can be easily expanded in the radial direction by the sealing element 39. By screwing on the screw cap 37, a reliable seal can be created while simultaneously stabilizing the thin-walled neck 25.

[0055] In contrast to the prior art, in which the screw cap has the material flexibility necessary for the sealing effect, according to the invention, the screw cap 37 has the necessary increased stability, and the container neck 25 has the necessary flexibility.

[0056] The screw cap 37 preferably has a depression 43, which acts as the sealing element 39. The depression can have a projection for a tool in order to be able to transmit a torque to the screw cap 37 in a form-fitting manner. The projection can be a hexagon socket 45 or another polygon.

[0057] The screw cap can also have a guarantee ring 47 with predetermined breaking webs 48, as shown in FIG. 9 to 13. The neck 25 also provides sufficient height that a retaining band 49 can be provided on the guarantee ring 47. The retaining band 49 holds the unscrewed threaded part 50 captively to the guarantee ring 47 or to the neck 25 after unscrewing.

[0058] The base 19 may have a groove 51 (FIG. 8) into which the base 19 can be folded. After emptying the refill container, it can be folded up particularly small thanks to the groove 47 and requires little space when disposed of. FIGS. 3 and 4 show a base shape or a container cross-section which has the shape of a cam. This cam shape ensures that the user intuitively grips the bottle on the wider side.

[0059] The extrusion blow-molded container 11 is integrally formed, and the neck 25 together with the container body 13 is blown in one mold. The neck is therefore an integral component of the container 11 and does not have to be subsequently inserted therein and connected thereto. The container 11 is characterized by the fact that it is lightweight and thin-walled, and yet has a sufficiently stable and accordingly tight screw cap. The stability is created by tightening the screw cap 37 on the neck 25, since this compresses and stabilizes the external thread 31 along the longitudinal axis and the thin-walled neck 25, which can be widened at its open edge 42 by the sealing element 39.

LIST OF REFERENCE SIGNS

[0060] 11 Container [0061] 13 Body of the container [0062] 15 First end [0063] 17 Second end [0064] 19 Base [0065] 21 Standing surface [0066] 23 Opening [0067] 25 Neck [0068] 27 First shoulder [0069] 29 Second shoulder [0070] 30 Lateral surface [0071] 31 External thread [0072] 33 Main axis [0073] 35 Secondary axis [0074] 37 Screw cap [0075] 39 Sealing element [0076] 41 Internal thread [0077] 42 Open edge of the support ring [0078] 43 Depression [0079] 44 Step [0080] 45 Hexagon socket [0081] 47 Security ring [0082] 48 Break-off webs [0083] 49 Holding strip [0084] 50 Threaded part [0085] 51 Groove