Extrusion blow-molded container with nut

Abstract

The invention relates to a container (11) having a nut (37), the container (11) being produced from a plastic material, in particular by blow molding, and the container (11) having a main body (13) having a first end (15) and a second end (17) positioned substantially opposite the first end, and having a side surface (30) located between the first end and the second end, wherein a base (19) having an upstanding surface (21) is formed at the second end (17), and an opening (23) is formed at the first end (15), and wherein the opening (23) is defined by a neck (25) surrounding the opening (23) and integrally formed with the container (11), an external thread (31) is formed on the neck (25), and wherein the nut (37) is provided with an internal thread (41), which when the nut has been placed in position, is inserted into the opening (23). The nut (37) has an internal thread (31) which interacts with the external thread (31), and wherein a sealing element (39) is formed on the inner side of the nut and protrudes into the opening (23) when the nut has been placed in position, and wherein the external thread (31) obtains the final rigidity of the external thread by threaded connection with the nut (37).

Description

Technical Field

[0001] The invention relates to a container with a screw cap according to the preamble of the claim, wherein the container is produced from a plastic material, in particular by extrusion blow molding. Prior art

[0002] The production of plastic containers, in particular plastic bottles, made of polyethylene or polypropylene, for example, takes place in an extrusion blow molding mold. In this case, the plastic suitable for blow molding is plasticized and introduced into a tube head by an extruder. In the tube head, the plastic is formed into a tube, which is introduced into a blow molding tool. The hose is introduced into the blow molding tool and inflated by an overpressure of gas when the tool is closed, so that the hose expands and is pressed against the inner wall of the cavity of the blow molding tool and assumes the shape of the inner wall, which has a shape opposite to that of the container. The container blown out of the hose is cooled by the inner wall until the plastic hardens. The container is then removed from the opened blow molding tool. In a separate step, the so-called scrap formed by the protrusion of the tube during the closing process of the blow molding mold and usually connected to the removed container is cut off and can be directed for recycling. The hose can be single-layer or multi-layer.

[0003] Typically, during the blow molding process, an outlet opening is formed at one end of the container. Thus, during the filling process, the container is filled via the outlet opening. Therefore, the filling speed at the filling line depends on the cross-section of the outlet opening and the density of the product to be filled with the container.

[0004] In order to increase the filling rate, WO 2017 / 072185 A1 discloses an extrusion blow molding container having a first open end and a second end. The first end has a first sealing surface and a second sealing surface. The sealing surface surrounds the filling opening and can be connected in a fluid-tight manner after filling. The second end is formed as a container base with an upright surface. The fact that the filling opening can extend over the entire cross section of the container at most makes it possible to quickly fill the container.

[0005] In order to pour the filling material, the container must be cut open or a closure element must be laminated between the sealing surfaces with the pouring opening. If the container is cut open, a pouring opening is created, which reduces user-friendliness, since auxiliary means are required to open it and the filling material may easily spill out during pouring. If a closure element is present, it must be inserted between the sealing surfaces before it can be welded to the sealing surfaces. Furthermore, the closure element may be made of a plastic different from that of the container, whereby disposable disposal of the container is not possible.

[0006] In order to overcome this disadvantage, a filling opening and a separate pouring opening can be provided on the extrusion blow moulding container. Preferably, the filling opening is larger than the pouring opening. Thus, the container can be quickly filled and the filling material can be accurately poured out or transferred to another container. In addition, when a nut for a small pouring opening is provided, the material requirement is reduced. However, due to the geometry of the container, it is impossible to use such a container on a conventional filling system without special adaptation.

[0007] Since these containers are designed specifically for use as refill packaging, special efforts are made to manufacture them using as little material as possible. The pour opening is crucial in the production of extrusion blow moulded containers if a thread is formed on the pour opening which is intended to interact with a closure element in the form of a screw cap.

[0008] The aim of reducing material usage conflicts with the stability of the thread, which is necessary to enable the container to be tightly closed with a screw cap.

[0009] The container is preferably made of HDPE, wherein the proportion of recycled HDPE is between 10% and 100% by weight. This makes the container very easy to extrusion blow mold, and is environmentally friendly and gentle on the material.

[0010] Purpose of the invention

[0011] The object of the present invention is to provide a container with a screw cap which is designed such that the container is closed reliably, ie in particular tightly, with the screw cap.

[0012] describe

[0013] The stated object is achieved in a container with a screw cap according to the preamble of claim 1, which container is produced from plastic material, in particular by extrusion blow moulding, by the features listed in the characterising part of claim 1. The dependent claims relate to developments and / or advantageous alternative embodiments.

[0014] Therefore, the present invention relates to a combination of a container and a nut with an internal thread having the following characteristics: the container is made of plastic material, in particular by blow molding, and has a main body, the main body having a first end and a second end positioned substantially opposite to the first end, and the main body having a side surface located between the first end and the second end, wherein a base with an upright 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 surrounds the opening and is formed integrally with the container, and the external thread is formed on the neck.

[0015] The combination is characterized in that the external thread acquires its ultimate rigidity by means of a threaded connection with the nut. Since the container is a lightweight container with thin walls for refilling purposes, this means that the neck with the external thread is also thin-walled and less stable. However, this instability can surprisingly be compensated by tightening the nut on the neck. Due to the thin neck wall and the low thickness of the external thread, the external thread can be compressed by the nut along the screwing axis. In addition to the neck, the external thread can also be formed in a material-saving manner. The rigidity is achieved by a kind of "accordion effect" and the opening is reliably sealed.

[0016] In a particularly preferred embodiment of the invention, the sealing effect between the sealing element and the neck is achieved by widening the neck when the sealing element protrudes into the neck. This type of sealing function allows the second neck to be designed to be particularly thin-walled, since the sealing element provides the necessary rigidity for producing the seal. This also allows a small amount of plastic material to be used to form the neck.

[0017] The invention is also characterized in that the wall thickness of the nut is greater than the wall thickness of the container. This means that the rigidity of the nut is greater than the rigidity of the container neck. This means that the normally low rigidity of the refill bag can be used in a surprising way in combination with the nut to form a tight and stable seal between the nut and the container neck.

[0018] In another preferred embodiment of the invention, the container has a wall thickness of 0.2 mm to 0.4 mm. This makes the container perfect as a refill container. The low wall thickness not only saves resources, but also allows the container to collapse when emptying. In addition, the low wall thickness in the area of ​​the neck allows the neck to flexibly adapt to the sealing element of the nut and the above-mentioned "accordion effect" can be achieved. The nut advantageously has a wall thickness of 0.7 mm to 1 mm. Such wall thickness dimensions ensure sufficient stability of the sealing element and the internal thread to ensure a reliable seal of the container opening.

[0019] It has proven to be advantageous if the wall thickness of the neck decreases towards the opening edge of the neck. The reduction in the neck wall thickness can be done in one step or by a continuous reduction. Due to the low wall thickness at the opening edge, the neck is particularly flexible and can easily expand when the sealing element is pressed into the opening.

[0020] In another preferred embodiment of the invention, the nut has a projection on which a tool can be applied and torque can be transmitted from the tool to the nut. Thus, the nut can also be screwed onto the neck for the first time when there is not enough space on the wide side of the container for a standard tool (capper) to attach the nut to the second neck and the capper cannot therefore grip the nut on its outside. The projection is preferably a hexagonal socket or another form-fitting connection by means of a polygon.

[0021] The protrusion is advantageously a recessed portion, which serves as a sealing element. Thus, the sealing element satisfies two functions, and in a corresponding design, the nut requires less plastic material for manufacture. Preferably, the invention is characterized in that the opening is defined by a neck around the opening, the neck being formed integrally with the container, and an external thread is formed on the neck, which can interact with the internal thread of the nut. This allows a particularly fast and cost-effective manufacture of the container. The one-piece design also ensures that the plastic material of the container and the plastic material forming the opening are identical. These features make further production steps obsolete, and the neck can be disposed of separately with the container.

[0022] In a particularly preferred embodiment of the invention, the container has no additional opening. This means that the blow mould can be produced cost-effectively and price drivers for complex blow mould forms are avoided. Compared to the variant with two necks, the welding process on the filling line is eliminated here. This eliminates the need to install a welding system on the filling line, resulting in significant cost savings for the customer.

[0023] Advantageously, the first shoulder and the second shoulder abut the neck. This allows the opening to have an optimized shape for the intended use of the refill container and allows the opening to merge into the side surface of the container in a smooth shape. It is therefore also preferred that the first shoulder and the second shoulder merge into the side surface of the container.

[0024] In another preferred embodiment of the invention, the opening is shaped so that, in a plan view of the container, it lies within the contour of the base of the container. The requirements for the blow mould are thereby simplified and the neck can be shaped precisely. Furthermore, this enables simplified palletizing, since the neck does not protrude. This is also advantageous if the container is to be decorated, i.e., printed, for example, if a label or the like is to be glued to the container, or if the container is to be wrapped with shrink film.

[0025] Advantageously, the opening is centrally located within the contour of the base of the container. This gives the container a symmetrical shape and is reminiscent of a bottle.

[0026] It may also be advantageous if the base has a major axis and a minor axis and the opening is located eccentrically on the major axis. This makes it easier to refill the filling material from the container into an existing container without the filling material spilling out.

[0027] Advantageously, the first shoulder has a convex shape starting from the neck.The first shoulder thus has an arched shape that curves outwards, allowing the neck to be positioned away outwards on the main axis depending on the application of the container.

[0028] It may also be advantageous if the first shoulder and the second shoulder have a concave shape starting from the neck and extending into the side surface in a convex shape. Thus, both shoulders can be S-shaped, which enables flow-improved pouring. The central / middle position of the neck also ensures that the shoulder angles can be made steeper. This ensures better compression pressure performance. Since the refill container is symmetrical, no bottle needs to be oriented on the filling line. This makes it possible to reduce costs.

[0029] In another particularly preferred embodiment, the neck is blow-molded together with the container. Thus, the entire container is manufactured in the blow-molding mold and only needs to be filled and closed with a screw cap. No further processing steps are required and the container is made of a single type of plastic material.

[0030] Further advantages and features become apparent from the following description of several exemplary embodiments of the invention with reference to the schematic drawings. In the accompanying drawings, in the schematic drawings which are not drawn to scale:

[0031] Figure 1 is a perspective view of an extrusion blow molded container in a first embodiment having a neck formed by the container surrounding an opening;

[0032] Figure 2 yes Figure 1 A side view of a container;

[0033] Figure 3 yes Figure 1 A plan view of the container;

[0034] Figure 4 yes Figure 1 A bottom view of a container;

[0035] Figure 5 is a perspective view of an extrusion blow molded container in a second embodiment having a neck formed by the container surrounding an opening;

[0036] Figure 6 yes Figure 5 A side view of a container;

[0037] Figure 7 yes Figure 5 A plan view of the container;

[0038] Figure 8 yes Figure 5 A bottom view of a container;

[0039] Fig. 9 A first embodiment of a container having a screw-on nut is shown;

[0040] Fig.10 A second embodiment of a container having a screw-on nut is shown;

[0041] Fig.11 is a cross section through the neck of the container and the nut screwed onto the neck;

[0042] Fig.12 is a perspective cross-sectional view through a neck of the container and a nut threaded onto the neck; and

[0043] Fig.13 It is a perspective view of the nut.

[0044] Figures 1 to 4 and Fig. 9 ,or Figure 5 and Figures 8 to 10 A possible embodiment of a container is shown, which is produced from a plastic material by extrusion blow molding and is generally indicated by the reference numeral 11. The container 11 is particularly intended as a so-called "refill container". This means that the container is as light as possible and is stabilized by the filling material when the container is full. However, it has sufficient inherent stability to permanently retain its container shape. After the filling material has been completely transferred into the existing container, the refill container 11 can be folded so small that its filling volume is almost zero due to its relatively low inherent stability. This method is extremely sustainable, especially when the container is made of recycled plastic material. The container can be made of polyethylene or polypropylene.

[0045] The container 11 has a body 13 with a first end 15 and a second end 17 substantially opposite the first end 15. The second end 17 is closed fluid-tightly and is designed as a base 19 on which an upright surface 21 is formed.

[0046] The opening 23 is blow-molded at the first end together with the remaining container 11 and is thus formed in the blow mold simultaneously with the container 11 by inflating the container material. Preferably, the container 11 does not have any further openings. Thus, the blow mold can be designed simply, the container 11 requires less material for its production, and the opening can be closed by the nut 37 after filling. Compared to the variant with two necks, the welding process on the filling line is eliminated here. Therefore, there is no need to install a welding system on the filling line, making the purchase and operation of the filling system more cost-effective.

[0047] The opening 23 is defined by a neck 25 which surrounds the opening 23 and is adjoined by a first shoulder 27 and a second shoulder 29. The shoulders 27, 29 merge seamlessly into a side surface 30 of the container 11.

[0048] In a particularly advantageous embodiment, the opening 23 is located in the mold separator and within the contour of the base 19 ( Figure 3 and Figure 7). This ensures that there is sufficient material to form the external threads 31 on the neck 25.

[0049] Figure 3 and Figure 7 The base 19 of the container is shown to have a major axis 33 and a minor axis 35. The opening 23 or the neck 25 is located on the major axis so that the requirements described in the previous paragraph are met.

[0050] In accordance with Figures 1 to 4 In the first exemplary embodiment of the invention, the opening 23 is arranged eccentrically on the main axis 33 in plan view. Figures 5 to 8 In a second exemplary embodiment of the invention, the opening is arranged centrally on the main axis.

[0051] In the first embodiment, the first shoulder 27 extends in a convex manner from the neck 25, while the second shoulder 29 has a concave shape starting from the neck and extending in a convex shape in the side surface. This places the neck 25 in a convenient position to allow the filling material to be transferred to another container without spilling.

[0052] In the second embodiment, the first shoulder 27 and the second shoulder 29 have a concave shape starting from the neck 25 and extending into the side surface 30 in a convex shape.

[0053] The external thread 31 has been specially developed for use in lightweight packaging, particularly refill containers. It can be formed with very little material and only obtains its ultimate rigidity through the threaded connection with the nut 37, as it is compressed by the attached nut 37.

[0054] The nut 37 has a sealing element 39 and an internal thread 41 which protrudes into the opening 23 when the nut is attached to the neck 25. In addition, the nut has an internal thread 41 which cooperates with the external thread 31. The sealing element 39 is designed to be rigid so that it can widen the thin-walled neck 25. This results in a sealing effect between the neck 25 and the nut 37. The rigidity of the nut 37 and therefore of the sealing element 39 and the internal thread 41 is achieved by the nut 37 having a wall thickness of, for example, 0.8 mm.

[0055] Fig.11 and Fig.12 The opening edge 42 of the neck is shown, the wall thickness of which is reduced. The reduction can be achieved via a step 44. The wall thickness of the opening 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 the nut 37, a reliable seal can be formed while stabilizing the thin-walled neck 25.

[0056] Compared to the prior art in which the screw cap has material flexibility required for the sealing effect, according to the present invention, the screw cap 37 has the necessary increased stability and the container neck 25 has the necessary flexibility.

[0057] The nut 37 preferably has a recess 43 which serves as a sealing element 39. The recess may have a projection for a tool in order to be able to transmit torque in a form-fitting manner to the nut 37. The projection may be a hexagonal socket 45 or another polygon.

[0058] The nut may also have a safety ring 47 with a predetermined breaking web 48, such as Figures 9 to 13 The neck 25 also provides sufficient height so that the retaining band 49 can be set on the safety ring 47. After unscrewing, the retaining band 49 holds the unscrewed threaded portion 50 to the safety ring 47 or the neck 25 in a captive manner.

[0059] The base 19 may have a groove 51 ( Figure 8 ), into which groove the base 19 can be folded. After emptying the refill container, the refill container can be folded particularly small thanks to the groove 47 and requires little space when disposed of. Figure 3 and Figure 4 A base shape or container cross section having a cam shape is shown. This cam shape ensures that the user "intuitively" grips the bottle on the wider side.

[0060] The extrusion blow molded container 11 is formed integrally and the neck 25 is blow molded together with the container body 13 in one mold. Therefore, the neck is an integral part of the container 11 and does not have to be subsequently inserted into the container and connected to the container. The container 11 is characterized in that the container is lightweight and thin-walled and also has a sufficiently stable and therefore tight nut. Stability is created by tightening the nut 37 on the neck 25, because this compresses and stabilizes the external thread 31 and the thin-walled neck 25 along the longitudinal axis, which can be widened by the sealing element 39 at its opening edge 42.

[0061] Reference numerals list :

[0062] 11 Container

[0063] 13. The body of the container

[0064] 15 First end

[0065] 17 Second end

[0066] 19 base

[0067] 21 Upright Surface

[0068] 23 Opening

[0069] 25 Neck

[0070] 27 First Shoulder

[0071] 29 Second Shoulder

[0072] 30 Side surface

[0073] 31 External thread

[0074] 33 Main axis

[0075] 35 Secondary axis

[0076] 37 Nut

[0077] 39 Sealing element

[0078] 41 Internal thread

[0079] 42 Opening edge of support ring

[0080] 43 Depression

[0081] 44 steps

[0082] 45 Hexagon socket

[0083] 47 Safety Ring

[0084] 48 Disconnect the web

[0085] 49 Keep Strip

[0086] 50 Threaded part

[0087] 51 Groove

Claims

1. A container (11) having a screw cap (37), wherein the container (11) is produced from a plastic material, in particular by blow moulding, and (11) has a body (13) having a first end (15) and a second end (17) located substantially opposite the first end, and having a side surface (30) located between the first end and the second end, wherein a base (19) having an upright surface (21) is formed at the second end (17), and an opening (23) is formed at the first end (15), and wherein the opening (23) is defined by a neck (25) surrounding the opening (23) and being formed integrally with the container (11), and an external thread (31) is formed on the neck (25), wherein the nut (37) is provided with an internal thread (41) which interacts with the external thread (31) when the nut has been put in place, and wherein a sealing element (39) is formed on the inner side of the nut and which protrudes into the opening (23) when the nut has been put in place, It is characterized in that The external thread (31) is threadedly connected with the nut (37) to obtain the final rigidity of the external thread.

2. The container with a screw cap according to claim 1, characterized in that: The sealing effect between the sealing element (39) and the neck (25) is achieved by widening the neck (25) when the sealing element (39) protrudes into the neck (25).

3. The container with a screw cap according to claim 1 or 2, characterized in that: The wall thickness of the nut is greater than the wall thickness of the container.

4. A container with a screw cap according to any one of the preceding claims, characterized in that The container (11) has a wall thickness of 0.2 mm to 0.4 mm.

5. A container with a screw cap according to any one of the preceding claims, characterized in that The nut (37) has a wall thickness of 0.7 mm to 1 mm.

6. A container with a screw cap according to any one of the preceding claims, characterized in that The wall thickness of the neck (25) decreases in the direction of the opening edge (42) of the neck.

7. A container with a screw cap according to any one of the preceding claims, characterized in that The nut (37) has a projection to which a tool can be applied and torque can be transmitted from the tool to the nut.

8. The container with a screw cap according to claim 7, characterized in that: The protrusion is a recessed portion (43) which serves as the sealing element (39).

9. A container with a screw cap according to any one of the preceding claims, characterized in that The container is used to refill filling material into an existing container and can be collapsed to a near zero filling volume after emptying.

10. A container with a screw cap according to any one of the preceding claims, characterised in that The container (11) has no further openings.

11. A container with a screw cap according to any one of the preceding claims, characterized in that A first shoulder and a second shoulder (27, 29) adjoin the neck (25).

12. A container with a screw cap according to any one of the preceding claims, characterised in that The first shoulder and the second shoulder (27, 29) transition into the side surface (30) of the container (11).

13. A container with a screw cap according to any one of the preceding claims, characterised in that The opening (23) is formed such that, in a plan view of the container (11), the opening is located within the contour of the base (19).

14. A container with a screw cap according to any one of the preceding claims, characterised in that The opening (23) is centrally located within the contour of the base (19).

15. A container with a screw cap according to any one of the preceding claims, characterised in that The base (19) has a major axis (33) and a minor axis (35), and the opening (23) is located eccentrically on the major axis (33).

16. A container with a screw cap according to any one of the preceding claims, characterised in that The first shoulder (27) has a convex shape starting from the neck (25).

17. A container with a screw cap according to any one of the preceding claims, characterised in that The first and second shoulders (27, 29) have a concave shape starting from the neck (25) and extending into the side surface (30) in a convex shape.

18. A container with a screw cap according to any one of the preceding claims, characterised in that The neck (25) is blow-moulded together with the container (11).

19. A container with a screw cap according to any one of the preceding claims, characterised in that The container (11) is made of HDPE, wherein the proportion of recycled HDPE is between 10% and 100% by weight.

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