Pallet container with drainage tube

Abstract

A pallet container for storage and for transportation of liquid or free-flowing contents has a thin-walled, rigid plastic inner container composed of thermoplastic material, having a tubular lattice frame, which, in the form of a supporting jacket, tightly encloses the plastic inner container and which is composed of horizontal and vertical tubular bars which are welded to one another, and having a rectangular bottom pallet, on which the plastic inner container bears and to which the tubular lattice frame is firmly connected.

Claims

1. A pallet container (10) for storage and for transportation of liquid or free-flowing contents, the pallet container comprising: a thin-walled, rigid plastic inner container (12) composed of thermoplastic material; a tubular lattice frame (14), which, in the form of a supporting jacket, tightly encloses the plastic inner container (12) and which is composed of horizontal and vertical tubular bars (18, 20) which are welded to one another; and a rectangular bottom pallet (16), on which the plastic inner container (12) bears and to which the tubular lattice frame (14) is firmly connected, wherein the rigid plastic inner container (12) has an upper filler neck, which can be closed off by means of a screw cover (26), and a bottom-side extraction connector, with an extraction fitting (24) which can be closed off, and wherein a flexible inliner (28) composed of plastic film is inserted into the rigid plastic inner container (12) and, at the bottom, is connected in a gas-tight and liquid-tight manner to at least one of the extraction connector and the extraction fitting (24) of the rigid plastic inner container (12) via an inliner connector (30), wherein the inliner connector (30) of the inliner (28) is directly connected in a materially bonded manner to a cylindrical tube connector (34) of an extraction fitting housing (32) of the extraction fitting (24) and facing toward an inner side of the rigid plastic inner container (12), and wherein a drainage tube (46) is firmly inserted into the cylindrical tube connector (34) of the extraction fitting housing (32) of the extraction fitting (24).

2. The pallet container as claimed in claim 1, wherein the inliner connector (30) is, via a cylindrical welding region (44), directly connected in a materially bonded manner radially from an inside to an inner surface of the cylindrical tube connector (34) of the extraction fitting housing (32).

3. The pallet container as claimed in claim 1, wherein the inliner connector (30) of the inliner (28) is welded directly onto the cylindrical tube connector (34), facing toward the inner side of the rigid plastic inner container (12), of the extraction fitting housing (32) of the extraction fitting (24).

4. The pallet container as claimed in claim 1, wherein the inliner connector (30) is, by means of a welding device introduced from an outer side of the extraction fitting (24) into the extraction fitting housing (32), welded onto an inner surface of the cylindrical tube connector (34) of the extraction fitting housing (32).

5. The pallet container as claimed in claim 1, wherein the inliner connector (30) is, by means of a welding device introduced from an inner side of the inliner into the extraction fitting housing (32), welded onto an inner surface of the cylindrical tube connector (34) of the extraction fitting housing (32).

6. The pallet container as claimed in claim 1, wherein the drainage tube (46) projects some way through the welded-in inliner connector (30) into the inliner (28).

7. The pallet container as claimed in claim 6, wherein the extraction fitting (24) comprises a 3-inch extraction fitting, and, for the insertion of the drainage tube (46), a base disk (48) is inserted into the cylindrical tube connector (34) of the extraction fitting housing (32) of the extraction fitting (24).

8. The pallet container as claimed in claim 7, wherein the drainage tube (46) and the base disk (48) are produced as a one-part component in an injection-molding process.

9. The pallet container in claim 7, wherein the base disk (48) is fixed in a rotationally fixed manner in the extraction fitting (24) by means of a metallic grounding screw (52) screwed in through the cylindrical tube connector (34) of the extraction fitting housing (32).

10. The pallet container as claimed in claim 7, wherein the inliner (28), which is welded directly onto the extraction fitting (24), comprises a simple rectangle-shaped pillow liner, and corners of the plastic film of the flexible inliner (28) which face toward the extraction fitting (24) folded in to a center, and is rolled up from both sides to the center to form a bar-like film roll and is covered by a tubular packing cover (56).

11. The pallet container as claimed in claim 10, wherein the tubular packing cover (56) consists of a thin plastic film and is provided with a separating line which extends in a longitudinal direction and which can be easily torn open.

12. The pallet container as claimed in claim 10, wherein the extraction fitting (24) with welded-on inliner (28), with drainage tube (46), inserted therein, with base disk (48), and with packing cover (56) pulled thereover comprises an easily exchangeable module unit (58) which unfolds automatically during filling.

13. The pallet container as claimed in claim 1, wherein the inliner connector (30) is produced as a tubular film with a small diameter and the flexible inliner (28) comprises a tubular film with a large diameter, the inliner connector and flexible inliner being constructed from a same multi-layer composite film material with same barrier properties.

14. The pallet container as claimed in claim 1, wherein arranged in the screw cover (26) at the closeable container opening in the top of the plastic inner container (12) is a bung opening which can be closed off by means of a 2-inch or ¾-inch bung plug and which serves for connection of a compressed-air pump.

15. The pallet container as claimed in claim 1, wherein the flexible inliner connector (30) of the inliner (28) is welded from an outside via a cylindrical welding region onto [an outer surface of the cylindrical tube connector (34) of the extraction fitting housing (32) by means of a matched annular welding device, wherein only after insertion of the inliner into the plastic inner container is the extraction fitting, provided with the inliner, welded by way of a weld flange of the extraction fitting onto a corresponding weld flange on a lower rigid extraction connector of the plastic inner container.

16. A method for producing a module unit consisting of an extraction fitting with welded-on inliner, with drainage tube, inserted therein, with base disk, and with packing cover pulled thereover, which module unit serves for being inserted into a pallet container as claimed in claim 1, the method comprising: introducing the inliner connector into a part of the cylindrical tube connector of the extraction fitting housing of the extraction fitting which faces toward the plastic inner container, introducing a pin-like welding device into the inliner connector from an inner side of the inliner, welding the inliner connector radially from an inside to an inner surface of the cylindrical tube connector of the extraction fitting housing by means of the pin-like welding device, removing the pin-like welding device and welding shut a still open bottom seam in the inliner, folding and rolling up the inliner to form a bar-like film roll, and pulling a tubular, thin-walled packing cover over the rolled-up inliner.

17. A method for producing a module unit consisting of an extraction fitting with welded-on inliner, with drainage tube, inserted therein, with base disk, and with packing cover pulled thereover, which module unit serves for being inserted into a pallet container as claimed in claim 1, the method comprising: introducing the inliner connector through the extraction fitting housing and externally turning the inliner connector inside out over an outer extraction fitting housing of the extraction fitting, introducing a pin-like welding device from an outside through the extraction fitting housing and the inliner connector, welding the inliner connector radially from an inside to an inner surface of the cylindrical tube connector of the extraction fitting housing by means of the pin-like welding device, removing the pin-like welding device and trimming away an excess length of the inliner connector, folding and rolling up the inliner to form a bar-like film roll, and pulling a tubular, thin-walled packing cover over the rolled-up inliner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained and described in more detail below on the basis of an exemplary embodiment illustrated schematically in the drawings, in which:

(2) FIG. 1 shows, in a front view, an IBC according to the invention with an inserted inliner,

(3) FIG. 2 shows, in a cross-sectional illustration, a 3-inch extraction fitting with an inserted welding device for welding in the flexible inliner connector,

(4) FIG. 3 shows, in a cross-sectional illustration, the 3-inch extraction fitting fully assembled with a fully welded-in inliner connector,

(5) FIG. 4 shows, in plan view, an inliner in the form of a rectangular pillow liner,

(6) FIG. 5 shows, in a side view, a drainage tube with a base disk,

(7) FIG. 6 shows a front view of the drainage tube with base disk,

(8) FIG. 7 shows a perspective view of the drainage tube with base disk,

(9) FIG. 8 shows a plan view of the half-folded-in pillow liner with extraction fitting,

(10) FIG. 9 shows a schematic cross-sectional illustration through the rolled-up pillow liner with mounted packing cover,

(11) FIG. 10 shows an inliner/extraction fitting module unit for which picking has been completed,

(12) FIG. 11 shows the inliner/extraction fitting module unit in the pushed-in state in the plastic inner container with fitted packing cover, and

(13) FIG. 12 shows the inserted inliner/extraction fitting module unit with open packing cover in the unrolled partial state prior to complete unfolding.

DETAILED DESCRIPTION

(14) In FIG. 1, the reference sign 10 denotes a pallet container according to the invention for storage and for transportation of in particular hazardous liquid or free-flowing contents. For use with hazardous contents, the pallet container 10 meets particular test criteria and is provided with corresponding official approval. The main components of the pallet container 10 consist of a thin-walled, rigid plastic inner container 12, which is produced from thermoplastic material in a blow-molding process, a tubular lattice frame 14, which, in the form of a supporting jacket, tightly encloses the plastic inner container 12, and a bottom pallet 16, on which the plastic inner container 12 bears and to which the tubular lattice frame 14 is firmly connected. The outer tubular lattice frame 14 consists of horizontal and vertical tubular bars 18, 20 which are welded to one another.

(15) The bottom pallet 16, in the version illustrated, is in the form of a composite pallet having an upper steel-sheet carrying plate, having a tubular steel carrying frame arranged therebelow and having plastic corner and center feet. It would however also be possible for any other conventional bottom pallet composed of wood, steel or plastic to be built at the bottom.

(16) A label panel 22 composed of a thin steel sheet for identification of the respective contents is attached to the front side of the tubular lattice frame 14. In the top, the plastic inner container 12 has a relatively large container opening with a diameter of 150 mm or 225 mm, said container opening being closable by means of a screw cover 26. For extraction of the liquid content, a corresponding extraction fitting 24 is connected centrally to the lower edge of the front wall of the plastic inner container 12 in a protected position in a set-back wall recess.

(17) In order to protect the rigid plastic inner container 12 from direct contact with the contents introduced and from non-detachable adhering material thereof, and to allow multiple re-use of the valuable plastic inner container 12, prior to each new filling of the pallet container 10, a thin-walled, flexible inliner 28 or, according to an earlier description, a film bag is inserted into the rigid plastic inner container 12, this being connected at the bottom to the extraction connector of the rigid plastic inner container 12 or to the extraction fitting 24. Sensitive contents are often transported and stored in a closed system, with exclusion of air and without admission of oxygen, in containers with a diffusion barrier (aroma protection) or under aseptic conditions. Filling and extraction are realized here exclusively via the filling and extraction fitting at the bottom side. Since the blow-molded plastic inner containers, consisting of HD-PE (high-density polyethylene), of the large-volume pallet containers generally exhibit only very poor diffusion barrier properties or are completely lacking in this regard, for high-grade sensitive contents, multi-layer inliners with good diffusion barrier properties are generally used and inserted into the rigid blow-molded plastic inner containers.

(18) In the present exemplary embodiment, the plastic inner container 12 of the pallet container 10 is equipped in the bottom-side extraction region with a 3″ extraction connector with external thread (DN 80 coarse thread). A 3″ extraction fitting 24 with integrated threaded flange 36 (DN 80 coarse thread) is firmly screwed onto said extraction connector.

(19) The 3″ extraction fitting 24, which is illustrated in more detail in FIG. 2, is in the form of a DN 80 extraction fitting with flat valve and DN 100/DN 80 coarse thread, is produced from polyethylene (PE) and exhibits high resistance with respect to many types of liquids. On the front side, for the purpose of protection against soiling and damage, the 3″ extraction fitting 24 is closed off by a screw cap of the DN 80 coarse thread type that is screwed onto the cylindrical extraction fitting housing 32. Approximately in the center of the cylindrical extraction fitting housing 32, a disk-shaped rotary flap (not visible here) is arranged on a rotary shaft 38 with an upper handle 40.

(20) For the purpose of explaining the process-related production sequence for welding on the flexible inliner connector 30, as a demonstration, a pin-like welding device 42 with a cylindrical welding region 44 is pushed into the cylindrical extraction fitting housing 32, the disk-like rotary flap and the rotary shaft 38 with handle 40 being removed for this purpose.

(21) In FIG. 2, it can be seen that the inliner connector 30 of the inliner 28, according to the present invention, is welded directly on the cylindrical tube connector 34 of the extraction fitting housing 32 of the extraction fitting 24. In this case, the inliner connector 30 is, via a cylindrical welding region 44, welded radially from the inside directly onto the inner surface of that side of the cylindrical tube connector 34 of the extraction fitting housing 32 which faces toward the inner side of the plastic inner container 12. As a special feature in terms of manufacture, the inliner connector 30 is, by means of a pin-like welding device 42 introduced from the outer side of the extraction fitting 24 into the extraction fitting housing 32, welded onto the inner surface of the cylindrical tube connector 34 of the extraction fitting housing 32.

(22) At the front side, the welding device 42 is equipped with an expandable welding head which presses the plastic film of the inliner connector 30 in the intended welding region 44 on the inner surface of the cylindrical tube connector 34 of the extraction fitting housing 32 with a predefinable pressure and predefinable application of heat over a specific period of time, and welds said plastic film to the tube connector in a materially bonded manner. After the welding process, surplus film material of the inliner connector 30 is cut off directly behind the welding region 44.

(23) Another possibility for welding the inliner connector 30 into the extraction fitting housing 32 is, in terms of manufacture, that the inliner connector 30 is, by means of the pin-like welding device 42 introduced from the inner side of the inliner 28, welded to the inner surface of the cylindrical tube connector 34 of the extraction fitting housing 32. Here, the pillow liner 28 is still open on its rear side when delivered since the welding device 42 is introduced from the inside through the film bag, which is still open on the rear side, into the inliner connector 30 or into the cylindrical tube connector 34 of the extraction fitting housing 32. Only after this process step of welding in the inliner connector is the bottom seam of the pillow liner 28 welded shut and tightly closed.

(24) After completion of the welding process for the inliner connector 30 at the 3-inch extraction fitting 24, a drainage tube 46 is inserted into the inliner 28 or into the extraction fitting housing 32 by means of a base disk 48. Afterwards, a grounding cable is screwed onto the extraction fitting housing 32 by way of a grounding screw 52, and the rotary shaft 38, with disk-like rotary flap and handle 40, is re-installed. Finally, the extraction fitting housing 32 is closed off in a gas- and liquid-tight manner by a screw cap screwed on at the outer side. FIG. 3 illustrates the fully assembled filling and extraction fitting 24 with welded-in inliner connector 30.

(25) As can be seen in FIG. 4, the thin-walled flexible inliner 28, in a preferred embodiment, is in the form of a simple rectangle-shaped pillow liner 28 and produced from a tubular film with a large diameter, while the bottom-side, flexible inliner connector 30 is produced from a tubular film with a small diameter, wherein both of these always consist of the same multi-layer composite film material with the same barrier properties; this excludes disadvantageous plastic material-penetrating diffusion processes. In the present case, the inliner 28 and the inliner connector 30 consist of a transparent LDPE film with a film thickness of 100 μm. The film thickness, in particular in the case of multi-layer films with a diffusion barrier, may also be between 100 μm and 250 μm, preferably approximately 150 μm. The dimensions for example for a 1000 l pallet container are approximately 2140×2200 mm. The inliner connector 30 is welded centrally into the inliner 28 at a distance of approximately 490 mm from the boundary. Here, the cut length of the inliner connector 30 should be approximately 250 mm and the diameter should be approximately 90 mm.

(26) The drainage tube 46, with open lattice structure, and the base disk 48 are illustrated in FIG. 5. The drainage tube 46 is a stable, flexurally rigid grid tube with numerous apertures, which make it possible for the residual liquid to flow away in an optimum manner. For a diameter of approximately 45 mm, the length of the drainage tube 46 should be at least 250 mm. As can be seen in FIG. 6, the base disk 48 has a large bore for the drainage tube and has at least two further large apertures 54 for an unhindered throughflow of liquid. FIG. 7 shows the base disk 48 and the drainage tube 46 once again in a perspective view. At the outer side, the base disk 48 is provided with a set of graduated diameter steps 50 (larger than the inner-side diameter step) and, together with the drainage tube 46, is pushed from the outflow side of the extraction fitting 24 up to a stop at a corresponding set of graduated diameter steps at the inner end of the inner-side tube connector 34 and into the extraction fitting housing 32.

(27) After the base disk 48, with the drainage tube 46, has been placed at the lowest position, the base disk 48 is fixed in a rotationally secured manner by means of a grounding screw 52 screwed in from the outside. The position of the base disk 48 is thus secured against rotation or slipping in the extraction fitting housing 32 by way of the grounding screw 52.

(28) The illustrated standard 3-inch (CCS 100×8) extraction fitting 24 is equipped with a grounding cable connection provided for the EX antistatic designs, wherein the electrical connection to the liquid contents is established by way of the screwed-in grounding screw 52. After all the components have been connected to one another, the rotary shaft 38 with sealing flap and handle 40 are re-inserted into the extraction fitting 24 and the extraction fitting housing 32 is closed off by a screw cap screwed on at the outer side.

(29) Subsequently, the pillow liner 28 is firstly folded, then rolled up and finally picked (packed into a cover). FIG. 8 shows the pillow liner 28 in the semi-finished folded-in state. For the purpose of folding together the pillow liner 28, any air is forced out of the inliner. For complete de-aeration, a negative-pressure hose may be connected to the extraction fitting 24 and a vacuum may be applied. This considerably simplifies the folding, rolling and picking. The completion of the process in which the pillow liner 28 forms with the extraction fitting 24 a module unit 58 that is simple to handle comprises the following steps:

(30) 1st step: laying out the finished pillow liner and folding down the upper region to a point transverse to the extraction fitting,

(31) 2nd step: folding in the upper corners at the extraction fitting to the center of the pillow liner,

(32) 3rd step: folding in the lower region up to the horizontal center of the pillow liner,

(33) 4th step: folding in the outer wings up to the vertical center,

(34) 5th step: folding in the outer wings up to the vertical center again,

(35) 6th step: rolling up the outer edges up to the center,

(36) 7th step: pulling a tubular packing cover onto the rolled-up inliner.

(37) FIG. 9 shows, in a purely schematic illustration, a cross section through the rolled-up inliner 28 with tubular packing cover 56. The packing cover 56 has, indicated at the top, a separating seam, or perforated bursting seam, which can be easily torn open.

(38) The extraction fitting 24 with directly welded-on and rolled-up inliner 28 and with pulled-on tubular packing cover 56 constitutes an exchangeable module unit 58 and is ready for use in any plastic inner container of a pallet container. Such an inliner extraction fitting module unit 58 for which picking has been completed is illustrated in FIG. 10. For warehousing and for protection of the packing cover 56, which can be easily torn open, the prepared module units 58 may in each case be inserted into a thin-walled protective tube, for example a metal sleeve or a cardboard tube, which can be screwed into the threaded flange of the extraction fitting housing.

(39) For the purpose of equipping a pallet container 10 with a module unit 58, the tubular packing cover 56 is inserted through the bottom-side extraction connector and into the plastic inner container 12. The inner diameter of the 3-inch extraction connector is 83.2 mm. The tubular packing cover 56 of the rolled-up pillow liner 28 has a diameter of 75 mm. The introduction of the tubular pack and screwing of the extraction fitting housing onto the 3-inch extraction connector can therefore be carried out in a correspondingly simple manner. A module unit 58 inserted into the plastic inner container 12 in such a manner is shown in FIG. 11.

(40) There are furthermore embodiments of pallet containers in which the bottom-side extraction connector of the plastic inner container is not in the form of a screw connector with external thread but in the form of a short tube connector with weld flange. Accordingly, the associated extraction fittings are also provided with a container-side weld flange and, according to requirement, are welded onto the extraction connector of the plastic inner container according to the hot plate-welding (butt-welding) process. In realizing the present invention for container embodiments of said type, it may be provided that the inliner connector 30 is, in a simple manner by means of a matched annular welding device, welded from the outside via a cylindrical welding region onto the outer surface of the cylindrical tube connector 34 of the extraction fitting housing 32, and only after insertion of the inliner into the plastic inner container is the extraction fitting, provided with the inliner, welded by way of its weld flange onto the corresponding weld flange on the lower rigid extraction connector of the plastic inner container.

(41) The filling and emptying of the pallet container 10 takes place exclusively via the bottom-side 3-inch extraction fitting 24 of the plastic inner container 12. During the filling, the contents are normally guided into the container under pressure, such that, after the packing cover 56 is torn open along a, for example perforated, bursting seam, the pillow liner 28 is firstly completely unrolled, unfolded and finally lifted until it has attained its entire volume. For this purpose, FIG. 12 illustrates the state, when filling begins, in which the packing cover 56 has opened and the inliner 28 is unrolled on both sides.

(42) When emptying, the pillow liner 28 collapses and retains a residual volume of approximately 5 liters. Here, the drainage tube 46 prevents the inliner film from blocking the outlet and a relatively large quantity of contents from remaining in the plastic inner container 12.

(43) With the aid of a corresponding connection (separate or in an upper filling cover), the plastic inner container 12 can be subjected to pressure so as to force further contents out of the pillow liner 28. Here, a pressure as low as 0.1 bar is sufficient. The positive pressure results in further residual liquid being forced out of the inliner 28, with a small residual amount of approximately 0.5 liters (approximately 0.05%) remaining. In order to bring about this promotion and improvement of the emptying of residual material from the inliner 28, there is arranged, for connecting a compressed-air pump, a corresponding container opening at a suitable position in the top of the plastic inner container 12. Preferably, the container opening is designed centrally in the upper screw cover 26 of the filling opening of the plastic inner container 12 as a 2-inch bung opening, which can be closed off in a gas- and liquid-tight manner by a 2-inch bung plug.

(44) Replacement of a Used Pillow Liner 28:

(45) After the contents have been completely extracted, the pillow liner 28 can be removed from the plastic inner container 12. For this purpose, the pallet container 10 is expediently tipped on its “back”, so that the extraction fitting 24 points upward. The tightly closed extraction fitting 24 is unscrewed from the rigid extraction connector and, with the welded-on inliner nozzle 30 and the pillow liner 28, is pulled out from the extraction connector of the plastic inner container 12 up to a point slightly behind the drainage tube 46. Directly behind the drainage tube 46, the pillow liner 28 is, for example using a cable tie or binding wire, squeezed off and closed off in a drip-tight manner. The extraction fitting 24 and pillow liner 28 are then separated from one another. The pillow liner 28, by means of a gripper, is removed through the large filler neck in the top of the plastic inner container 12, that is to say pulled out laterally in this case. The pillow liner 28 and extraction fitting 24 are subsequently passed on to a recycling process and, following possibly required external cleaning of the pallet container 10, a new inliner/extraction fitting module unit 58 can be inserted into the plastic inner container 12 and the pallet container 10 is prepared again for inexpensive re-use for renewed filling with liquid contents.

(46) The use of the module unit 58 according to the invention with the extraction fitting 24 and inliner 28 welded directly to one another makes it possible to protect the value of high-quality plastic inner containers 12 which are usable multiple times.

(47) The insertion of the module unit 58 and the inliner 28 is so simple that anyone can carry out the process.

(48) Since for the module unit 58 according to the invention, no changes to the existing sealing system are made, no new approval tests are required for use with hazardous liquid contents. Upgrading of already used—possibly even stained—plastic inner containers of re-used pallet containers for re-use for high-quality contents is made possible. Furthermore, the residual quantities of contents remaining in the inliner 28 can be reduced to a minimum with the aid of a drainage tube 46 and through application of a small positive pressure in the plastic inner container 12 during the emptying process for the pallet container 10.

(49) The present invention consequently offers the customer a correctly functioning solution for protection from adhering material of residual contents in the plastic inner container in the case of new pallet containers and with multiple re-use of used IBCs.