CROSS-REFERENCE TO RELATED APPLICATION

This is the United States national phase of International Patent Application No. PCT/EP2017/000360, filed Mar. 23, 2017, which claims priority to German Application No. 10 2016 003 496.3, filed Mar. 24, 2016, the entire contents of each of which are hereby incorporated by reference.

FIELD OF THE DISCLOSURE

The invention relates to a thin-walled rigid plastics-material internal container having an inliner for a pallet container or a similar large-volume retainer for storing and for transporting liquid or free-flowing filling materials, comprising two longer side walls, a shorter rear wall, a shorter front wall, an upper base having a closable filling connector and a container base, wherein on the base side, in the center of the front wall, a lower removal region having a protective-housing-shaped molding, directed inward toward the inside of the plastics-material internal container is provided for disposing a closable removal fitting in a protected recessed manner, and wherein a flexible inliner from a thin-walled plastics-material or composite-material film, the former at the top being connected to the filling connector or/and at the bottom being connected to the removal connector having a removal fitting of the rigid plastics-material container, is inserted into the rigid plastics-material internal container.

BACKGROUND

Pallet containers (the usual trade name being “Intermediate Bulk Containers”, hereunder also referred to as “IBC” or “IBCs”) are extensively used for storing and for transporting, in particular hazardous, liquid or free-flowing filling materials, above all in the chemical industry. In the latter, IBCs are predominantly used for transporting liquid chemicals. The majority of these chemical products are classified as hazardous liquid filling materials because they pose a risk to the health of humans and animals and to the environment in a concentrated form. During storage and transportation in IBCs, the chemicals may stress, such as discolour, contaminate, embrittle, or damage, the HDPE material of the plastics-material internal containers in such a manner that the used internal containers cannot simply be washed and reused. In the case of a usual multiple use of used IBCs, the only remaining option is the replacement of the damaged plastics-material internal container with a new internal container. Considering that a plastics-material internal container, depending on the list of requirements, may weigh approx. 14 kg to 18 kg, this however represents a costly solution involving a not insignificant waste of plastics material. A more cost-effective solution lies in protecting the plastics-material internal container by means of an inserted thin inliner, or film bag, respectively, against contamination by the respective filling material, and on account thereof enabling multiple reuse or repeated use, respectively, of the internal container. In this instance, only the contaminated inliner needs to be disposed of, said inliner for a 1000 liter IBC, depending on the film thickness, merely having a weight of approx. 0.7 to 1.3 kg in terms of the plastics-material mass thereof, and a new inliner has to be inserted in order for the IBC to be reused.

Inserting thin-walled film bags, or inliners, respectively, into rigid box-shaped external containers, such as large rigid cardboard boxes or cardboard sleeves (bag in box) is a measure that has been usual for years. However, only cylindrical, cuboid, or cushion-shaped inliners of “simple construction” have always been available for square-shaped or rectangular-shaped external containers. Said inliners may be used without problems for containers that have an externally located removal system. Said simple inliners are not easily usable for IBCs having blow-molded stiff or rigid plastics-material internal containers, respectively, or for similar large-volume (that is to say with a capacity of typically approx. 500 l and more, commonly up to 1250 l for IBC containers) containers with inner containers having a protective housing that is molded inwardly into the internal container for a recessed removal fitting that is protected from external influences, because during handling in the case of installation, filling, removal, and removal from the rigid internal container they consistently lead to problems, there in particular inevitably being a formation of creases in the region about the lower removal connector.

The use of a thin film-type inliner in a rigid plastics-material internal container having a molded protective housing therein for the removal fitting of a usual pallet container is known from publication EP 2 090 528 A1. The focus herein is inter alia on securely fixing the thin-walled inliner removal connector in the rigid removal connector of the plastics-material internal container with the aid of the screwed-on removal fitting. In this case, the front periphery of the thin tubular film, using a sealing flange and a sealing lip, is jammed at the end side by an annular shoulder in the housing screw nut of the removal fitting on the threaded sleeve (having an external thread) that is welded to the bottle removal fitting. However, when the housing screw nut is placed ready for screwing, the periphery of the thin tubular film that is folded over can no longer be tightly held and no longer be seen; said folded-over periphery may easily slide out of place herein or even be imparted creases. Small pimples on the film periphery and respective depressions in the end wall of the threaded sleeve are intended to counteract this. In any case, fixing and securing the inliner removal connector against rotation is performed only by clamping, once the thread of the housing screw nut has been completely tightened. It has to be ensured at the same time that the opening lever of the removal fitting is exactly in the vertical position.

In the case of another large container that is known from U.S. Pat. No. 655,657 B1, the undesirable formation of creases in the region of the protective housing of the removal fitting within the plastics-material internal container has been identified as disadvantageous, and the thin-walled removal connector of the inliner as a supposedly suitable countermeasure has not been positioned in the base side proximity of the inliner front wall but rather close to the front-side periphery of the lower base of the cuboid-shaped inliner. Upon insertion of the inliner into the rigid internal container of the IBC, the front-side periphery of the lower base is then folded up in a rectangular manner, and the thin-walled removal connector of the inliner is guided through the rigid removal connector of the internal container and fixed. On account thereof however, the inliner cannot bear on the front wall of the internal container in a fully planar manner, and free spaces or cavities, respectively, remain below the inliner, laterally next to the protective housing of the internal container. As the filling of the IBC is increased, the inliner is pressed by the liquid filling material onto the protective housing and, laterally thereto, onto the base of the rigid internal container. Herein, the inliner is here too inevitably withdrawn from the lateral corner regions of the rigid internal container, and the inevitable formation of creases of the thin-walled inliner arises here too, even if this arises rather toward either side and no longer directly in front of the outlet opening of the removal connector. The problem of the formation of creases is thus also not completely solved here either.

In the case of all known IBCs, the thin-walled inliners by way of the lower flexible removal connector thereof are fastened to the lower rigid removal connector and at the top by way of the flexible filling connector of the former to the upper rigid filling connector of the plastics-material internal container, otherwise being freely suspended from top to bottom. When filling the pallet container, irrespective of this being from the top or from below in the case of a so-called “base filling”, the liquid filling material is most often filled into the inliner at still increased process temperatures under pressure, or by way of a sharp jet. Intense fluttering of the film material often arises herein. The inliner base is frequently withdrawn from the container corners, forming creases which later may block the base-side removal opening during a removal of filling material. Depending on the filling level, the inliner together with the liquid content thereof by virtue of the external transportation rocking motions acting thereon wobbles back and forth in the upper region or airspace of the plastics-material internal container such that tensile stresses that are constantly variable act on the upper filling connector of the inliner, and the film material can rip or the flange weld seam of the inliner connector of the upper inliner wall can tear open. In order to obviate this phenomenon, expensive stress-resistant film materials have to be used in the production of the inliner. Composite films having advanced barrier properties unfortunately have only a very poor resistance to stress, and cannot be employed in many applications.

GENERAL DESCRIPTION

The present invention is based on the object of specifying a plastics-material internal container having an integrated inliner for pallet containers (IBC) or other large-volume retainers for storing and for transporting in particular hazardous liquid or free-flowing filling materials, said plastics-material internal container no longer having the disadvantages of the prior art and in particular avoiding with high reliability a formation of creases of the inliner in the interior of the rigid internal container in assembly and in pressurized filling with liquid filling material and in emptying the filling material. The application or handling, respectively, of the containers having inliners in terms of the user (filler and emptier) of the large-volume liquid containers, on account of the particular constructive design of said containers, should not differ in any way from the handling of containers without inliners.

This object is achieved by the special features of patent claim1. The features in the dependent claims hereunder describe further advantageous potential design embodiments of the plastics-material internal container according to the invention. The proposed technical teaching opens up improved safety in the handling of IBCs and other large-volume container systems having shape-adapted inliners for use in IBCs and other large-volume containers having a blow-molded plastics-material internal container having a protective housing, inwardly molded in the internal container, for disposing the removal fitting in a protected recessed manner within the external lattice cage or other retainer of the pallet container or other large-volume container system. It has been established that customers do not accept and refuse further use of thin-walled inliners in IBCs when leakages of the inliner and/or disruptions in the removal of filling material arise, for example by virtue of the formation of creases of the inliner on the base, that clog the removal connector of the rigid plastics-material internal container from the inside.

An asset protection of high-value and multi-use-capable plastics-material internal containers is furthermore enabled by the constructive measures of the present invention by way of a disruption-free use of cost-effective inliners or film bags, respectively, such that no more material is unnecessarily wasted in terms of valuable blow-molded plastics-material internal containers.

This is effected in constructive manner in that the cuboid-shaped flexible inliner in the lower removal region also has a wall recess, directed inward and adapted so as to correspond to the protective-housing-shaped molding of the rigid plastics-material container (hereunder also synonymously referred to as a “removal fitting protective housing”), having two lateral wall parts, an upper wall part, and a rearward wall part having a flexible removal connector molded thereon, and is configured so as to bear in an exact fit on the internal surface of the molding of the removal fitting protective housing that protrudes into the interior of the rigid plastics-material container. On account thereof, in the case of an inliner that has been inserted into the plastics-material internal container there are no cavities below or laterally next to the still empty inliner base, that during continuous filling of known IBCs with liquid filling material are always filled, inevitably leading to distortions of customary inliners and to the formation of creases of the latter.

In a constructive design embodiment of the invention it is expediently provided herein that the cuboid-shaped flexible inliner is welded together from three blank panels, and to this end comprises an upper horizontal lid part having a centric filling connector, a lower horizontal base part having a notch with a notch shape that corresponds with the base shape of the wall recess, and a vertically encircling side-wall blank panel having area portions for the two lateral wall parts, as well as the upper wall part, and the rearward wall part of the wall recess of the inliner.

In a production-technology related design embodiment of the invention it is provided that the three blank panels in each case are welded together by way of a weld seam that horizontally encircles the external edge of the upper lid part and the external edge of the lower base part, and for closing the side-wall blank panel are welded together by way of a weld seam that runs vertically from top to bottom in the center of the front wall and through the center of the wall recess.

In another preferred production-technology related design embodiment of the invention it is provided that the three blank panels in each case are welded together by way of a weld seam that horizontally encircles the external edge of the upper lid part and the external edge of the lower base part, and for closing the side-wall blank panel are welded together by way of a weld seam that runs vertically from top to bottom in the center of the rear wall, wherein a weld waste running vertically from top to bottom up to the wall recess, for removing excess film portion above the wall recess, is provided in the center of the front wall. In the production of inliners having a weld waste, the weld seam of the weld waste advantageously does not run through the upper and rearward wall part of the wall recess of the inliner. The position of the welded annular-disk-shaped flange periphery of the flexible inliner removal connector is then also free from a vertical weld seam running therethrough.

Surprisingly, in the inliner according to the invention, the length of the upper horizontal weld seam is configured so as to be shorter than the length of the lower horizontal weld seam, or the upper weld seam circumference of the upper lid part is configured so as to be shorter than the lower weld seam circumference of the lower base part, and the front-side vertical weld seam of the side-wall blank panel is configured so as to be longer than the height of the inliner cuboid. This is enabled by integrating the area portions for the two lateral wall parts and for the upper and the rearward wall part of the wall recess of the inliner into the vertically encircling side-wall blank panel. This indeed necessitates somewhat more cutting waste in terms of film material, and a curved weld seam in the upper and rearward wall part of the wall recess, but this does save complex welding of four individual small wall parts of the wall recess.

According to one particularly preferred process-technology related embodiment of the invention it is provided that the inliner after insertion and welding to the rigid filling connector and removal connector of the plastics-material internal container is inflated using compressed air, and excess air is removed without residue by vacuum pumps from the intermediate space between the external surface of the inliner and the internal surface of the plastics-material internal container until no air and no intermediate space remains between the inliner and the plastics-material internal container such that a stable vacuum is set, said vacuum, upon gas-tight closure of the container opening by way of which the excess air has been evacuated, being durably maintained during the entire intended use of the pallet container until the next replacement of the used inliner. An extraordinary handling friendliness of the pallet container according to the invention is achieved in that the flexible inliner by way of the upper filling connector thereof is welded in a materially integral manner to the upper filling connector of the rigid plastics-material internal container, and by way of the lower thin-walled removal connector thereof is welded in a materially integral manner to the lower removal connector of the rigid plastics-material internal container, in each case in a gas-tight and liquid-tight manner, while the entire external surface of the inserted inliner is operatively connected to the entire internal surface of the plastics-material internal container and is connected to the latter in a force-fitting manner. On account thereof it is precluded with utmost reliability that creases continue to be able to be formed in front of the lower removal connector in the inliner. The inliner sits like a second skin in the plastics-material internal container, so to speak. In order to enable vacuum pumping, an additional container opening may be disposed at any suitable location in the upper base. The container opening is preferably embodied as a 2-inch spout opening, which is closable in a gas-tight and liquid-tight manner by way of a 2-inch spout plug, preferably having an inbuilt one-way valve. A vacuum/compressed-air pump is connected to the container opening on demand.

