Title of Invention

A PACKAGING TUBE

Abstract

The invention relates to a plug-in closures on packaging containers, in particular on packaging tubes for fluid or pasty filling materials, are not deemed to be operationally reliable when pressures act on the container and thus the filling material therein, in other words plug-in closures can come uncontroUedly open. The invention proposes a packaging tube with a plug-in closure whose operational reliability is markedly improved.

Full Text

The invention relates to a packaging tube. The invention generally concerns a packaging container, in particular a packaging tube. Packaging containers, in particular packaging tubes, include a tube body with a head which is moulded thereon and which in turn is formed from a shoulder and a discharge portion. The discharge portion co-operates with a closure. Known closure members include screw caps which can be screwed to the discharge portion, flap closures which cover over the discharge opening, and plug-in closures. Screw closures require additional material, in comparison with thread-less closures, for the purposes of providing the screwthreads on the discharge portion and in the cap. Made from plastic material by injection moulding or press moulding, the tools have to be divided for the removal of screw closures, either by means of mould jaws or mould sliders, or components of the tools have to be designed in such a way as to be rotatable. The additional amount of material required and the complexity of the moulding tools are found to be disadvantages, in relation to screw closures. Heads with flap closures include a cover or lid as the closure member, which is cormected to the head by way of a hinge, generally a strip-shaped web portion of small cross-sectional dimension. In addition, closures of this kind have locking means which hold the cover or lid in the closed position. The moulds for heads with flap closures are of a simpler configuration than those for rotational closures, but the differences in the amounts of material involved (head, cover or lid, hinge and locking means) can give rise to filling problems so that it is necessary to involve an increased checking expenditure, in regard to complete casting of a moulded body. In comparison with the screw closure, the additional amount of material for the locking means and the hinge is less, and the mould tool is also structurally simpler, but the additional checking expenditure nullifies the advantages of the flap closures, in comparison with rotational closures. So that the cap and the lid or cover can perform the fimctions in the closure which are attributed to them, they have to be brought individually into engagement with the discharge portion after they have been manufactured, and this is a working operation which admittedly can be automated by means of tools but which constitutes an additional step which the tube manufacturer or user has to carry out. The manufacturing technology for plug-in closures, the latter including a closure body which can be inserted into a discharge opening, with an actuating device, does not impose the above-mentioned disadvantages thereon. The moulds for the production of heads and plug-in closures are simple, there is no additional need of material, checking and monitoring precautions can be reduced to a minimum and, if desired, the head and the plug-in closure can be produced in the form of one moulded member. In spite of those advantages the plug-in closure has hitherto not been in a position to gain widespread acceptance, particularly in the field of flexible packaging tubes, this being attributable to the fact that its operational reliability does not correspond to that of rotational and flap closures. The term operational reliability is used here to mean the resistance that a closure opposes to movements of the contents of a tube therein. Plug-in closures oppose insufficient resistance to movements of the contents of the tube, triggered off by loadings applied to the tube body, in comparison with rotational and flap closures, and for that reason the plug-in closure is viewed as being a closure of low to inadequate operational reliability. The object of the present invention is to provide a packaging container, in particular a packaging tube, with a plug-in closure of adequate operational reliability. That object is attained by a packaging container having the characterising features as described herein. Advantageous configurations of a packaging container are achieved with the subjects and features as described herein. Further advantages, features and details of the invention are apparent from the description hereinafter of a preferred embodiment and the accompanying drawings in which: Figure 1 is a partly sectional view showing the discharge end of a packaging container in accordance with the invention, with a head and with a closure body moulded on the head in the insertion direction. Figure 2 shows a plan view of the packaging container shown in Figure 1, Figure 3 is a partly sectional view showing the discharge end of a packaging container in accordance with the invention, with a head and with a closure body moulded on the head in the opposite direction to the insertion direction, Figure 4 shows a plan view of the packaging container shown in Figure 2, and Figure 5 shows a detail at the locations X in Figures 1 and 3, showing the connection of the closure bodies moulded to the head. Hereinafter identical parts of the packaging containers shown in the Figures are denoted by the same references. Figures 1 and 3 show the discharge end of a packaging container designed in accordance with the invention, in the form of a flexible, that is to say compressible tube 10. The tube 10 includes a tube body 11 and a head 12 which is connected to the tube body 11 and on the discharge opening 13 of which is moulded a closure body 14, being moulded thereon in the insertion direction (Figure 1) or in the opposite direction to the insertion direction (Figure 3). The tube body 11 comprises a foil with a longitudinal seam weld, preferably a plastic foil, which can be of such a nature as to include one plastic material in a single layer (mono-foil) or a plurality of plastic materials in a multi-layer structure, in the form of a so-called laminate. In accordance with the invention, preferred are so-called thin mono-foils and laminates of a thickness of from 0.1 mm to 0.25 mm, preferably a thickness of from 0.125 mm to 0.2 mm. The term laminate also includes those multi-layer foils which include a metal foil as a barrier layer, the metal foil being covered on both sides with plastic materials. The tube body 11 can also be produced by extrusion, in which case the extrusion is limited to single-layer and multi-layer tube bodies of plastic materials, without a metal barrier layer. In the longitudinal seam welding operation, tube bodies are produced from a strip of plastic material (mono-foil) or laminate foils, by shaping the strips to form a tube and welding the longitudinal edges of the strips. Laminates of the layer structure PPH/EVOH/PPH with EVOH as the barrier layer, PPH/PA/PPH with PA as the barrier layer, PE/EVOH/PE with EVOH as the barrier layer, PE/PET/PE with PET as the barrier layer, and PE/PA/PE with PA as the barrier layer, and of a thickness of from 0.1 µm to 0.5 µm, preferably from 0.15 µm to 0.25 µm, have proven to be desirable as the foil for tube bodies. The connection between the tube body 11 and the head 10 is made during the operation of moulding the head or by arranging the tube body on a prefabricated head 12. For the purposes of connecting the head 12 to an end of the tube body 11 during the operation of moulding the head, two processes are known, namely the press moulding process and the injection moulding process. The material of the head generally comprises a low-density or high-density polyethylene (LDPE, HDPE) because those plastic materials can be joined by a fusion procedure to a large number of plastic materials of different chemical compositions. In the case of laminates, an outer layer of the laminate always forms the inwardly disposed layer (lining) of a tube body. In a corresponding manner, a head can also be made from a plastic material of the same chemical composition as that of the lining, thus for example PPH. The head 12 includes a cylindrical discharge portion 16 which is arranged at its centre, also referred to as the neck 16, through which the discharge opening 13 axially passes. Adjoining the discharge portion 16 is the tube head shoulder 17 which is connected at its outer peripheral surface 18 or edge 18 to the tube body 11. The wall thicknesses of the discharge portion 16 and the tube head shoulder 17 are such or the head 12 as a whole is made from a so flexible material that upon a loading applied to the surface of the tube shoulder 17, which is towards the interior of the tube, the head deforms, that is to say flexes. Flexing is used here to denote the increase or reduction in the angle at which the shoulder 17 is disposed in relation to the centre line (tube axis) of the head 12. The flexing effect, that is to say deformation of the head under a load, that is to say a pressure on the part of the pressure-loaded contents of the tube, causes the outlet end of the discharge opening 13 with the ring 26 to be narrowed, whereby a pressure is applied to the closure plug. The flexing effect is promoted by tube body foils having the claimed thickness dimensioning. Flexing of the head 12 with a reduction in the size of the discharge opening 13 with or without a ring 26 advantageously contributes to impeding displaceability of the closure plug 20 in the discharge opening 13. The closure body 14 is moulded on the downstream end face 19, closing the discharge opening 13, being moulded thereon in the insertion direction in Figure 1 and in the opposite direction to the insertion direction in Figure 3. The closure body 14 includes a round closure plug 20 and a flat wing or blade 21 connected to the closure plug 20. The reference to insertion direction means that the closure plug 20 is connected with its free end face to the downstream end face 19 of the discharge portion 16, while in the opposite direction to the insertion direction means that a round projection 22 at the side of the closure body 14, which is in opposite relationship to the closure plug 20, is moulded to the end face 19 of the discharge portion 16, closing the discharge opening 13. In the embodiment shown in Figure 1 the closure plug 20 stands on the neck 16 while in the embodiment shown in Figure 3, it projects away from the neck 16. The embodiments of the tube head 12 shown in Figures 1 and 3, that is to say the embodiment with a closure plug 20 which stands thereon and which projects away therefrom, have the advantage that, for manufacture thereof, whether by press moulding or injection moulding, the mould portions 24 only have to be separated in one plane, that is to say the plane of the drawing, while only bars 25, forming the internal configuration of the heads 12, have to be pulled out of the longitudinally divided mould portions 24, being an operation which is identical and involving comparatively the same time as that of extracting bars from undivided mould portions. A further advantage of the heads 12 which are designed in accordance with the invention is that, after the tubes 10 have been produced, that is to say after the tube head 12 and the tube body 11 have been joined together, the tubes 10 are closed at one end, and for example the devices for screwing on closure caps can be eliminated. The closure plug 20 is of a hollow-cylindrical configuration over predominantly the whole of its axial extent. In the embodiment shown in Figure 1, that is to say the tube head 12 with the closure plug 20 standing on the neck 19, the opening 23 forming the hollow cylinder is formed by an axial extension on the bar 25 which forms the inside surface of the head 12, while the opening 23 of the closure plug 20 as shown in Figure 3 is formed by a bar which extends in opposite relationship to the bar 25. The diameters of the discharge opening 13 and the closure plug 20 are such that there is a play-free sliding fit after insertion. As shown in Figure 5 the closure body 14 is fixed to the head 12 by means of a ring 26 which projects into the discharge opening 13 in the form of a step and to which the closure body 14 is connected at its end by way of a ring 27. The width and the thickness of the rings 26, 27 are preferably not the same, the thickness and the width of the ring 26 are larger than those of the ring 27. The inside diameters of the rings 26, 27 are the same and, before being torn away, are disposed in mutually axially successive concentric relationship. They are of such dimensions that, by rotation of the closure body 14, the ring 27 tears away from the ring 26, the latter forming the downstream end face 19 of the discharge portion 16, while the ring 27 forms part of the end face of the closure plug 20. In the embodiment with the closure plug 20 projecting away from the neck, as shown in Figure 3, the connection between the closure body 14 and the head 12 is the same as in the embodiment of Figure 1, except that it is not the closure plug 20 but the projection 22 on the wings or blades 21 that is connected to the tube head 12, with the projection 22 being disposed in concentric relationship with the tube head 12. This embodiment also provides that the closure body 14 is separated from the head 12 by rotation and equally there remains a ring 26 which projects concentrically into the discharge opening 13. The outer periphery of the closure plug 20 comprises, in the axial direction, a cylindrical portion 29 and a conical portion 30 which terminates at the end face of the closure plug 20. The conical portion 30 serves to make it easier to introduce the closure plug 20 which has been separated off, into the discharge opening 13, while the cylindrical portion 29 is dimensioned to form a sealing plug-in connection (play-free sliding fit) with the inside surfaces of the ring 16 and the discharge opening 13. In order to prevent the closure body 14 being moved uncontrolledly and independently out of the discharge opening 13 when the content of the packaging tube is under pressure, the closure plug 20 at the end is open and of a hollow and elastic configuration. The elasticity provides that the closure plug enlarges (expands) when a loading is applied and contracts when a loading is released. When pressure is applied to the tube body 11 and therewith to the packaged material, it is further applied to the packaged material in the opening 23 in the closure plug 20 and radially expands it, with an increase in the pressure between the closure plug 20 and the discharge opening 13 and the ring 26. When the loading is removed, the closure plug 20 resumes its original radial dimensions again. When a loading is applied, forces acting on the closure plug 20 in the axial direction are also involved. Those forces engage the bottom of the opening 23 and the end face of the closure plug 20. It has been found that the forces acting in the longitudinal direction have a relatively slight influence on the transversely directed, radial forces which increase the pressing effect. The dimensioning of the opening 23, also referred to as a pressure chamber 23 which is open at one side, that is to say at its end, is preferably to be implemented as follows. The axial extent (depth) of the pressure chamber 23 is to be from 70% to 100%, preferably from 75% to 95% of the length of the closure plug 20, and the diameter of the pressure chamber 23 is to be from 50% to 85%, preferably from 70% to 80% of the diameter of the closure plug 20. The length of the closure plug 20 preferably corresponds to the length of the discharge opening 13, while the cylindrical portion is to be from 60% to 85%, preferably from 75% to 80% of the length. Those dimensions afford operative surface areas which, with the filling material under pressure, are sufficient to fix the closure body 14 in the discharge opening 13 in such a way that, when the tube body 11 is subjected to a normal loading, sudden, uncontrolled movement of the closure body 14 out of the discharge opening is avoided. The ring 26 which is accommodated in the discharge opening 13 of the neck 16 and which coincides in flush relationship with its end face with the end face of the neck 16 is preferably of a thickness (axial extent) of from 0.1 mm to 0.4 mm, preferably from 0.2 mm to 0.3 mm, a width (radial extent) of from 0.7 mm to 1.3 mm, preferably from 0.8 mm to 1.1 mm, reducing the diameter of the discharge opening over a corresponding length. The ring 27 which connects the closure body 14 to the neck 16 is of a width of from 0.4 mm to 0.6 mm, preferably from 0.45 mm to 0.55 mm. The ring 26 has essentially three functions, in a tube 10 designed in accordance with the invention. Before the closure body 14 is twisted off the neck 16 the ring 26 carries the closure body. After the closure body 14 has been twisted off and inserted into the discharge opening 13, it forms a seal, together with the closure plug 20; if pressure is applied to the tube body 11 and the filling material, it maintains its sealing function and provides between the ring 26 and the closure plug 20 a zone of higher pressure than between the walls of the discharge opening and the closure plug 20. That multi-zone pressure, two zones being described here, advantageously influences the operational reliability of the packaging tube designed in accordance with the invention. WE CLAIM: 1. A packaging tube comprising a tube body with a tube head arranged at one end on the tube body, the tube head having a tube head shoulder and a neck with a discharge opening and a closure body with a closure plug which is inserted into the discharge opening, characterised in that the closure plug (20) is adapted to expand under loading on the part of the filling material in the tube (10) and to contract when the loading on the part of the filling material is removed. 2. The packaging tube as claimed in claim 1, wherein the closure plug (20) has a pressure chamber (23) which is open at the end and which extends in the axial direction of the closure plug (20). 3. The packaging tube as claimed in claims 1 and 2, wherein the length of the closure plug (20) corresponds to the length of the discharge opening (13). 4. The packaging tube as claimed in any one of claims 1 to 3, wherein the peripheral surface of the closure plug (20) has a cylindrical portion (29) and a conical portion (30), wherein the length of the cylindrical portion is from 60% to 85%, preferably fi-om 75% to 80% of the length of the closure plug (20). 5. The packaging tube as claimed in any one of claims 1 to 4, wherein accommodated in the discharge opening (13) of the neck (16) is a ring (26) which with its end face coincides with the end face (19) of the neck (16) and which reduces the cross-section of the discharge opening. 6. The packaging tube as claimed in any one of claims 1 to 5, wherein the head (12) and the closure body (14) are in the form of a moulded member. 7. The packaging tube as claimed in claim 6, wherein the closure plug (20) of the closure body (14) is moulded on the head (12) to close the discharge opening (13), in the insertion direction. 8. The packaging tube as claimed in claim 6, wherein the closure body (14) is moulded on the head (12) with the closure plug (20) projecting away from the head (12). 9. The packaging tube as claimed in any one of claims 6 to 8, wherein the closure body (14) is cormected to the downstream end face of the ring (26) and is adapted to be twisted off same. 10. The packaging tube as claimed in any one of claims 1 to 9, wherein the tube head (12), with the tube head being moulded on, is adapted to be flexible.

Documents:

140-mas-2002 abstract duplicate.pdf

140-mas-2002 abstract.pdf

140-mas-2002 claims duplicate.pdf

140-mas-2002 claims.pdf

140-mas-2002 correspondence others.pdf

140-mas-2002 correspondence po.pdf

140-mas-2002 description (complete) duplicate.pdf

140-mas-2002 description (complete).pdf

140-mas-2002 drawings duplicate.pdf

140-mas-2002 drawings.pdf

140-mas-2002 form-1.pdf

140-mas-2002 form-13.pdf

140-mas-2002 form-18.pdf

140-mas-2002 form-26.pdf

140-mas-2002 form-3.pdf

140-mas-2002 petition.pdf