PACKAGE FOR TRANSPORTING AND STORING BULK GOODS

Abstract: The invention concerns a package for transporting and storing bulk goods, said package comprising an outer package (11) and an inner package (12). The inner package (12) comprises an outer frame (13) and an inner frame (14) which are at least partly attached to each other. The perimeter of the outer frame (13) of the inner package (12) is greater than or equal to the perimeter of the inner frame of the outer package (11), and the perimeter of the inner frame (14) of the inner package (12) is smaller than or equal to the perimeter of the outer frame of the outer package (11). The internal pressure (P₁) prevailing in the package (10) is received as tension force (F₂) acting on the circumference of the outer package (11), said tension force producing a resultant force (F₃) acting from the corners of the outer package (11) on the package (11), said resultant force (F₃) reducing the tensions prevailing in the inner package (12) so that the juncture points (19) of the inner frame (14) and the outer frame (13) of the inner package (12) are substantially free of stresses.

Description: The invention relates to a package for transporting and storing bulk goods, comprising an outer package and an inner package, the inner package comprising an outer frame and an inner frame having a perimeter less than that of the outer frame, the difference between said perimeters being such that hollow spaces are formed at the corners of the outer frame between said outer frame and said inner frame, said inner frame being affixed to said outer frame at at least four circumferentially spaced positions such that a filled inner package has a stable block-like contour. Such a package is known from EP-A-0 276 878 or EP-A-0 247 696. The main advantage of a package according to EP-A-0 247 696 is the stable rectangular form of the filled package without bulging of the side walls, even in case relatively flexible material is used. Such a filled inner package can be bodily shifted in to a outer package of e.g. cardboard. By additionally using the reinforcing means according to EP-A-0 276 878 the strength and resistance of the container can be further improved. In case big quantities of bulk goods, e.g. from hundreds of kilos to several tons, have to be transported and stored, e.g. if the package is used as a maxibag as known from Finnish patent applications 61174, 57382 and 68590, problems can arise at the affixment positions between the inner frame and the outer frame of the inner package. At stacking such packages or during lifting of such a package the connection between said inner and outer frames can give way. The object of the invention is to further improve the packages known in the art in that the strength of the package is increased considerably, so that no risk of the package being broken exists during transportation, storing or lifting. According to the invention, as claimed in claim 1, this is achieved in that, when the package is filled, the perimeter of the outer frame of the inner package is greater than the perimeter of the outer package and the perimeter of the inner frame of the inner package is smaller than the perimeter of the outer package, such that when bulk goods are added filling the entire cross-sectional area of the inner package to at least 30%, the internal pressure prevailing in the package is received as tension forces in the outer package, said forces producing resultant forces acting from the corners of the outer package on the package thereby relieving the tension prevailing in the inner package at the affixment positions between the inner frame and the outer frame of the inner package. The package of the invention is such in structure that it can be lifted so that its bottom shape is not changed or that there is no risk of its walls being broken. The package of the invention is also stronger than the packages known in the art; hence, no danger of its becoming broken during transport exists. The package of the invention is such in structure that when stacking said packages one on top of one another no danger exists of the packaging material being torn on the sides of the package, which facilitates the storing arrangements. The invention is now described in detail, reference being made to the figures of the drawing enclosed in which Fig. 1 presents schematically an advantageous embodiment of the package of the invention. Fig. 2 presents schematically an advantageous embodiment of the inner package of the package of the invention. Fig. 3 presents schematically the cross-section of the package of the invention in height direction. Fig. A presents schematically the cross-section of a package design illustrating the state of art in height direction. Fig. B presents schematically a state-of-art package when said package is being lifted. Fig. 4 presents the package of the invention schematically when said package is being lifted, and Figs. 5A-5F present schematically various versions of the vertical cross-section of the package of the invention. As shown in Figs 1, the package 10 of the invention comprises an outer package 11 and an inner package 12. In the figure, the package width is indicated by letter W, length by L and height by H. In Fig. 2 is presented an embodiment example of the cross-section of the inner package 12 of the package of the invention in height direction. As shown in Fig. 2, the inner package comprises an outer frame 13 and an inner frame 14. The space defined between the outer frame 13 and the inner frame 14 is indicated by reference numeral 17 and the space inside the inner frame 14 of the inner package 12 by reference numeral 16. The package of the invention may, if needed, be provided with reinforcements 15 to support the inner package 12 in height direction. In Fig. 3 is presented an embodiment example of the cross-section of the package 10 of the invention in height direction. The package 10 comprises an inner package 12 within an outer package 11, said inner package being composed of an outer frame 13 and an inner frame 14. The outer frame 13 and the inner frame 14 of the inner package 12 are at least in part attached to one another. The affixment positions of the outer frame 13 and the inner frame 14 of the inner package 12 are indicated by reference numeral 19, and the corner points of the outer frame 13 of the inner package 12 by reference numeral 24. Example 1 The resistances of the package presenting the state of art, shown in Fig. A, and of the package of the invention, shown in Fig. 3, to internal pressure were mutually compared. The material of the package used to illustrate the state of art was made of polyethene, the volume of the package being 1250 liter bulk goods. A state-of-art bag at 2000 kg pressure stretched over 10%. When increasing the pressure to 2400 kg, one of the seams between the outer package 11′ and the inner package 12′ broke entirely. In a similar test, the package of the invention comprises an outer package 11 made of a standard woven FIBC bag, and an inner package 12 with no top part and bottom. In the test, the perimeter of the outer package 11 of the package 10 was about 2% smaller than the perimeter of the outer frame 13 of the inner package 12. At 10000 kg pressure, the stretch of the package 10 of the invention was only about 1%. At that pressure one of the seams of the outer package 11 began to deteriorate. The internal pressure P₁ prevailing in the package 10 of the invention is received as a tension force F₂ acting on the outer package 11. Said tension force F₂ yields a resultant force F₃ which enters through the corners of the outer package 11 as shown in Fig. 3. The resultant force F₃ decreases the stresses existing in the inner package 12 in that the affixment positions 19 are substantially free of stresses. It is taught by the invention to transfer in the package 10 of the invention the stresses in that all affixment positions 19 in the inner package 12 are more or less free of stresses. Example 2 In a reference test, the resistances of the package 10 of the invention and a package 10′ of the state of art were compared as to their dynamic loading. When lifting the package 10′, illustrating the state of art, as is shown in Fig. B, the forces are transmitted from the lifting loops 20′ directly to the affixment positions of the inner package. As shown by arrows, the forces F₄′ cause torsional loading in the affixment positions, and said loading becomes utterly critical. In addition, in the package 10′ of the state of art, the package bottom 21′ is, while being lifted, formed rounded in that it will not return straight when the package 10′ is placed back on the ground, which makes the package very unbalanced. When lifting the package 10 of the invention, as in Fig. 4, from the lifting loops, the loading forces F₄ are formed as shown by arrows. Hereby, the forces F₄ are mediated to the bottom 21 of the outer package, so that no torsional forces are mediated to the affixment positions of the inner package. In addition, the bottom 21 of the package of the invention remains straight during lifting, as a result that the package remains steadily upright when placing it back on the ground. Figs. 5A-5F present schematically various forms of the vertical cross-section of the package of the invention when package is filled up. When the package has been made from a very thin or reticulatedly woven material, the corners 23 of the package are formed round whereas most of the walls of the outer package 11 are even. When for manufacturing the package the material used is a rather rigid material, completely even packages with no rounded corners 22 are produced. The package of the invention has even walls and a square or rectangular vertical cross-section, and the package of the invention is resistant to static and dynamic forces so that no resultant force is focussed at the affixment positions 19 of the inner package. The perimeter of the inner frame 14 of the inner package 12 is equal to or smaller than the perimeter of the outer package 11 comprising the width W and the length L when the package 10 is filled. The perimeter of the outer frame 13 of the inner package 12 is the same as or greater than the perimeter of the outer package 11. When using the package of the invention, the inner package can be bent over the outer package. In the package 10 of the invention, for the joining material at the affixment positions 19 of the outer frame 13 and the inner frame 14 of the inner package 12 any material may be used. This is due to the fact that no forces are substantially focussed on the affixment positions 19. For instance, a piece of reticulated material or paper can easily be affixed to wood or plastic e.g. with self-adhesive tape. In other words, various materials can be combined using joining methods known in the art in that for each material an appropriate joining method is selected. When using the package of the invention, the juncture points in the corner points 24 of the outer frame 13 of the inner package 12 need not be closed when the package is filled with dry goods. This is due to the fact that the outer package 11 closes said points automatically during the filling. An advantage to be thus gained is easier bending of the unfilled inner package to become even. The inner package 12 in the package 10 of the invention may be at least in part attached to the outer package 11. The inner package 12 may also be wholly disconnected from the outer package 11. The mutual joining of the inner package 12 and the outer package 11 as well as its quantity are selected in accordance with the package and applications. The height of the outer package 11 of the package 10 of the invention is at least 33% of the height of the package when filled so that the filling material settles on the bottom. No maximum limitation in height is set for the package of the invention. The height of the outer frame 13 of the inner package 12 is at least 33% of the height of the package 10 when filled up. In this case, the outer package 11 is required to be at least 100% of the package height. The height of the inner frame 14 of the inner package 12 is at least 33% of the height of the package but no maximum limit is set for the height. When using the inner package 12 for dry goods, the package does not need to be provided with a bottom 21 or a lid 22. The inner package 12 presses automatically against the outer package 11 when filled up. When using the package of the invention for liquids, the inner package 12 is required to comprise at least a bottom 21. When using the package 10 of the invention for transporting and storing dry goods, the entire cross-sectional area of the package 10 can be filled. What is most important is that the regions 17 and 16 of the inner package are filled up to at least 30%. When using the package of the invention for liquids, only the regions 17 and 16 of the inner package 12 are filled, in which case the inner package 12 must be provided with a bottom 21. The package of the invention may be used as an application for a plurality of different packaging designs. The inner package of the invention may be used e.g. as the inner bag in a large-size, or maxibag. Hereby, the shape of the inner package becomes rounded. The invention is described in the foregoing referring merely to some advantageous embodiments thereof. Therefore, the invention is not intended to be confined in any way to concern only the above examples, and a plurality of variations and modifications are feasible within the scope of the inventive idea determined by the claims presented below.

Claims: A package (10) for transporting and storing bulk goods, comprising an outer package (11) and an inner package (12), the inner package (12) comprising an outer frame (13) and an inner frame (14) having a perimeter less than that of the outer frame (13), the difference between said perimeters being such that hollow spaces (17) are formed at the corners of the outer frame (13) between said outer frame (13) and said inner frame (14), said inner frame (14) being affixed to said outer frame (13) at at least four circumferentially spaced positions (19) such that a filled inner package (12) has a stable block-like contour, characterized in that when the package (10) is filled the perimeter of the outer frame (13) of the inner package (12) is greater than the perimeter of the outer package (11) and the perimeter of the inner frame (14) of the inner package (12) is smaller than the perimeter of the outer package (11), such that when bulk goods are added filling the entire cross-sectional area of the inner package (12) to at least 30%, the internal pressure (P₁) prevailing in the package (10) is received as tension forces (F₂) in the outer package (11), said forces producing resultant forces (F₃) acting from the corners of the outer package (11) on the package (10) thereby relieving the tensions prevailing in the inner package (12) at the affixment positions (19) between the inner frame (14) and the outer frame (13) of the inner package (12). A package according to claim 1, characterized in that, when the package is lifted, the forces (F₄) acting on the package (10) are transmitted to the bottom (21) of the outer package (11) in that the bottom (21) of the package (10) remains substantially straight when the package is lifted and placed back on the ground. Package according to claim 1 or 2, characterized in that the height of the outer package (11) is at least 33% of the height of the package (10) when filled in that the filling material settles on the bottom (21) of the package (10). Package according to claim 1 or 2, characterized in that the height of the outer frame (13) of the inner package (12) is at least 33% of the height of the package (10) when filled, in which case the height of the outer package (11) is equal to the height of said package. Package according to any one of claims 1-4, characterized in that the height of the inner frame (14) of the inner package (12) is at least 33% of the height of the package (10). Package according to any one of claims 1-5, characterized in that, when liquids are packaged, the inner package (12) has at least a bottom (21). Package according to claim 6, characterized in that, when liquids are packaged, only areas (17 and 16) of the inner package (12) are filled. Package according to any one of claims 1-8, characterized in that, when packaging dry goods, the package (10) is filled over its entire cross-sectional area, and that at least 30% of the areas (17 and 16) of the inner package (12) are filled. Package according to any one of claims 1-8, characterized in that the inner package (12) is at least partly attached to the outer package (11). Package according to any one of claims 1-9, characterized in that the inner package (12) of the package (10) is an inner bag of a large-size bag.

Inventors: BOOTS, GERARDUS ANTHONIUS MARIA
Applicants: BOOTS, GERARDUS ANTHONIUS MARIA
Application year: 1990
Main classification: B65D5
IPC codes: B65D25, B65D30, B65D88, B65D5