METHOD AND EQUIPMENT FOR MAKING PACKAGING ELEMENTS FROM FIBRE-PULP MATERIAL

Abstract: Packaging elements for supporting packaged articles (3) with non-planar surfaces in an outer package (4) are made from a starting material with a number of raised portions or projections (2) by post-shaping some (2a, 2b) of the said raised portions or projections by pressing in such a manner that they will cooperate to support the article (3). In this manner it is achieved that the same starting material (1,2) may be used for making packaging elements for articles of various shapes. The equipment in the form of press tools (not shown) may comprise upper and lower pressing blocks detachably secured to an upper platen and a lower press platen respectively, so that it is possible to move and/or exchange the pressing blocks for adaptation to packaged articles of various shapes.

Description: METHOD AND EQUIPMENT FOR MAKING PACKAGING ELEMENTS FROM FIBRE-PULP MATERIAL TECHNICAL FIELD The present invention relates to a method of making packaging elements of the kind set forth in the preamble of claim 1. BACKGROUND ART When carrying out methods of this kind, it has up to now been necessary to alter the moulds, with which the packaging elements are made, each time a change occurs in the shape of the articles to be packaged by using the packaging elements, e.g. by these elements being used as an intermediate layer or protecting element between the article concerned and a outer packaging means, frequently in the form of a corrugated-paper box. To change the mould is, however, a very costly ope¬ ration, and can only be defended from an economic point of view, if very large series are to be produced. For this reason, it has up to now been difficult to find a method for appropriate packaging of articles with non-planar sides, e.g. bottles, video cameras, cameras etc., and in many cases it has been necessary to use rather primitive solutions, such as the use of a loose filling in the form of foam-plastic elements or crumpled paper. DISCLOSURE OF THE INVENTION On this background, it is the object of the present invention to provide a method of the kind referred to ini¬ tially, with which it is possible in a reasonably eco¬ nomical manner to produce packaging elements for use in packaging articles with non-planar surfaces, even when relatively small series are to be produced, and this object is achieved with a method, which according to the present invention is characterized by the steps set forth in the characterizing clause of claim 1. By proceeding in this manner, it is possible for the initial part of the production of the elements to use the same mould all the time, viz. corresponding to the shape of the starting material, this material not until after the drying to the rigid state being adapted to the shape of the various articles to be packaged, such adaptation being possible to carry out at a substan¬ tially lower cost than what is required to modify the moulds. Advantageous embodiments for the method, the effect of which will be evident from the following detailed portion of the present specification, are set forth in claims 2-9. The present invention also relates to an equipment comprising press tools and/or counter-press tools for car¬ rying out the method according to the present invention, and according to this invention this equipment is charac¬ terized by the features set forth in the characterizing clause of claim 10. BRIEF DESCRIPTION OF THE DRAWINGS In the following detailed portion of the present specification, the present invention will be explained in more detail with reference to the drawings, in which Figure l in perspective shows an example of a star¬ ting material for use in carrying out the method according to the present invention, Figure 2, likewise in perspective, shows the star- ting material shown in Figure 1 after having been proces¬ sed according to the method of the invention, Figure 3 is a partial sectional view along the line III-III in Figure 2, Figure 4, likewise in perspective, shows the packaging element shown in Figure 2 together with an article to be packaged placed on and supported by the element, Figure 5 is a sectional view corresponding to Figure 3 and showing how the article shown in Figure 4 can be packaged in a corrugated-paper box with two packaging elements according to Figure 4 as intermediate layers, Figure 6 in perspective shows a lower press platen with a number of lower pressing blocks secured thereto, and Figure 7 is a sectional view corresponding to the line VII-VII in Figure 6, in addition to the lower press platen shown in Figure 6 also showing another press platen with an upper pressing block secured thereto, as well as the packaging element placed between the two press pla- tens. DESCRIPTION OF THE PREFERRED EMBODIMENTS The starting material shown in Figure 1 and in¬ tended for use when carrying out the method according to the present invention consists in a manner known in prin¬ ciple of a base material 1 in sheet or web form, and a number of raised portions or projections 2, in the example shown being in the shape of truncated square pyramids, placed in a pattern of rows in¬ tersecting each other at right angles on the base material 1. The starting material 1,2 is in a manner known per se produced from fiber material, e.g. by depositing fibers from a "soup" or pulp produced e.g. from vegetable fiber mass, especially wood pulp or paper pulp including recycled such, against a mould consisting of fine-mesh gauze, on the rear side of which a "negative" pressure is maintained to cause the fibers to be deposited by being filtered out on the mould. After this depositing step, the starting material is removed from the mould and dried until it becomes dry and rigid, thus presenting itself with roughly the same material properties as the well- known egg trays of the same material, and like these, it has roughly the same wall thickness at all points, i.e. also in the raised portions or projections 2. The starting material shown in Figure 1 can be used as it is for packaging purposes, e.g. as a protective insert between a corrugated-paper box and an article packaged therein, provided that the article has the same shape as the box, but having smaller dimensions corres¬ ponding to the interspace to be filled by this starting material. The present invention is, however, concerned with adapting the starting material shown in Figure 1 with a view to packaging articles that are not box-shaped, e.g. round, bottles, video cameras etc. , and this is achieved by, as show in Figures 2 and 3, modifying the shape of some of the raised portions or projections 2, so that these can support the packaged article in an appropriate manner. For this purpose certain raised portions or pro¬ jections 2a have been pressed down to a height far below their original half-height to form af dish-shaped top, while other projections 2b situated on opposite sides of the projections 2a are pressed down to form oppositely facing arched side surfaces lying on the same circular cylindrical surface as the arched top of the projections 2a. Further, projections 2c and 2d are partially pressed down to form composite surfaces, together with the pres- sed-down surface on the projections 2a and 2b forming a bed, in which a cylindrical article 3 can rest, cf. Fi¬ gures 4 and 5. As indicated in Figure 4, those parts of the projections 2c and 2d, which have not been pressed down and are situated facing the ends of the article 3, prevent the latter from sliding out of said bed in the longitudinal direction. As indicated in Figure 5, the article 3 may suit- ably be packaged in a corrugated-paper box 4, indicated in broken lines, by cutting-out two pieces of suitable size and extent from the base material 1 and placing the article 3 between these pieces inside the box 4. Figures 6 and 7 show a lower press platen 5 and an upper press platen 6 as preferably used when carrying out the method according to the present invention. The lower press platen 5 may e.g. be a rigid plate of steel or aluminium, in which uniform holes 7 are bored in a pattern corresponding to the pattern, in which the projections 2 and 2b-2d are placed, while in the upper press platen 6, consisting e.g. of the same material as the lower press platen 5, holes 8 with the same shape and in the same distribution as the holes 7 in the lower press platen 5 have likewise been bored. In preparation for producing packaging elements adapted to the shape of the article to be packaged, e.g. the cylindrical article 3 shown in Figures 4 and 5, a number of lower press blocks 9 and 9a-9d are secured to the lower press platen 5, of which press blocks 9a-9d are shaped corresponding to the desired shape of the projec¬ tions 2a-2d respectively, while lower press blocks 9 are solely placed in a number - which may equal zero - cor¬ responding to what is needed for guiding the starting material 1,2 in the press (not shown) concerned. At the same time, the upper press platen 6 is provided with one or a number of upper press blocks, in the example shown solely one single upper press block 10, the shape of which corresponds to the shape of that part of the cylin- drical article 3 to be supported by the projections 2a- 2d. All the press blocks are secured to the press platens concerned by means of screws 11. As shown in Figure 7, the lower press blocks may be provided with pressing-surface pads 12 of rubber. This reduces the risk of parts of the projections being pressed being torn to pieces during the pressing-down operation, and at the same time any minor variations in the wall thickness in the projections, which otherwise could cause problems, especially when simultaneously pressing a number of packaging elements from one single piece of starting material, are accommodated. The pressing operation is quite simply carried out by placing a starting material 1,2 as shown in Figure 2 on top of the lower press platen 5 shown in Figure 6 in such a manner that the projections 2 are moved down- wardly onto the lower press blocks 9 and 9a-9d. Then, the upper press platen 6 is moved downwardly towards the lower press platen 5, by which the upper press block 10 in cooperation with the lower press blocks 9a-9d ' shape the projections concerned so as to form the desired pro- jections 2a-2d. The pressing operation may possibly be carried out whilst providing suitable humidification and heating, e.g. by introducing hot air and/or heating the press blocks, as this will cause a considerable reduction in the tendency of the material after the pressing ope- ration to change its shape back to the original shape, such as is e.g. commonly known from the pressing (ironing) of garments made of textile material. When minor changes in the shape of the original projections 2 are required, the pressing operation may also be carried out without using lower press blocks, primarily in those cases, in which the whole top part of the projections concerned is to be pressed down. If the angle 13 shown in Figure 3 between the oppositely facing side walls in the projections 2 lies within the interval 20-40°, experience has shown that such a pressing-down operation causes the formation of "accordeon pleats" in the upper part of the projection without substantially reducing its strength. Tests having been carried out until now have indicated that this angle should preferably be approximately 30°. As shown and mentioned above, the example of a starting material for use when carrying out the method according to the present invention as shown in Figure 1 has a number of raised portions or projections 2 having the shape of truncated pyramids and being placed in a pattern of rows at right angles to each other, but the present invention may also be carried out using starting material, in which the raised portions or projections are differently shaped and/or placed in other patterns than here shown and described. In order to make the starting material as versatile as possible it is, however, preferred that the projections are at least uniform and placed in a regular pattern, e.g. like the one shown or in the form of a "honeycomb pattern", as this makes it considerably easier to adapt the press tools shown in Figures 6 and 7 to producing packaging elements of dif¬ ferent shape. It is also possible in a manner not shown to de¬ press one or a number of raised portions or projections completely, i.e. so that they no longer constitute raised portions, but are aligned with the base material. This could make it possible to place labels and/or imprints on the flattened-out parts, or to give room for an article to be packaged or parts of such an article - although only in those cases, in which it is not required that the packaging element is to protect the article against impact. Finally, it is also possible - likewise in a manner not shown - to depress one or a number of raised portions in such a manner that their external dimensions roughly correspond to the internal dimensions of one or a number of the remaining raised portions. This makes it possible to place two or more pairs of raised portions or projec¬ tions on top of each other, partly to achieve a mutual locking of the base material parts concerned, partly to increase the ability to absorb impact energy. 10 15 20 25 30 35

Claims: C L A I M S : 1. Method of making packaging elements to be used as packaging means for one or a number of articles or as intermediate material between an outer packaging means and one or a number of articles, said elements consisting of fiber-pulp material in a roughly uniformly thick layer shaped with raised portions or projections intended to abut against the article or articles, characterized in a) that as starting material are used preforms of fiber-pulp material shaped as a base material with a number of raised portions or projections and subsequently dried to a rigid state, and b) that said preforms are subjected to pressing in such a manner that a number of said raised portions or projections are depressed fully or partly in such a manner that when one or a number of the articles, the packaging of which said packaging elements are to be used for, are placed in contact with the elements in the regions of fully or partly ' depressed projections, the article or articles will at the same time abut against and be supported by at least some of the fully or partly depressed projections. 2. Method according to claim 1, characterized in that the pressing operation is carried out using a) press tools, the pressing surfaces of which at least on those parts working on the projections during the pressing operation correspond to that surface or those surfaces on the article or ar¬ ticles, against which the projections are to abut, said press tools being made to perform relative movement against the starting material on the side, from which the projections protrude, and b) counter-press tools with counter-projections cor¬ responding to the projections in the starting material, the surfaces of said counter-press tools facing said press tools being shaped corresponding to the shape of said parts of the press tools working on the projections during the pressing operation, said counter-press tools being made to perform relative movement against the press tools and the starting material on the opposite side of the latter (Figure 7) . 3. Method according to claim 2, characterized by the use of press tools and/or counter-press tools, in which at least the active surface on one of the two pres¬ sing members working on opposite sides of a projection in the starting material is shaped on a part of the member concerned consisting of rubber-elastic material. 4. Method according to any one or any of the claims 1—3, characterized in that the pressing operation is carried out in such a manner a) that at least one projection is completely depres¬ sed so that its material after the pressing ope¬ ration is in general alignment with the base mate¬ rial of the starting material, and/or b) that at least one projection is depressed in such .a manner that its height is reduced over at least part of its dimension extending parallel to the base material. 5. Method according to any one or any of the claims .-4: , characterized in that the pressing operation is carried out in such a manner that at least one projection is depressed so as to make its external shape and dimen¬ sions correspond at least approximately to the internal shape and dimensions of at least one other projection. 6. Method according to any one or any of the claims 1-5, characterized in that the pressing operation is carried out while supplying heat. 7. Method according to any one or any of the claims 1-6, characterized by the use of starting material in the form of sheets or web material with uniform raised portions or projections placed in a regular pattern, e.g. in rows crossing each other at right angles or in a honeycomb pattern. 8. Method according to any one or any of the claims 1-7, characterized in that one or a number of articles having the same shape as the article or articles to be packaged are used as a component of the press tool or tools. 9. Method according to any one or any of. the claims 1-8, characterized in the use of starting material in the form of sheets or web material consisting of a base material with raised portions or projections each con¬ sisting of at least one obliquely extending side wall and a top wall extending substantially parallel to the base material, and in which the angle between two mutually opposing side walls or mutually opposed parts of a side wall is between 20° and 40°, preferably approximately 30°. 10. Equipment comprising press tools and/or counter-press tools for carrying out the method according to any one or any of the claims 1-9, characterized by comprising at least a) a base plate (6,5) with securing means (8,7) placed in a pattern corresponding to the pattern, in which the raised portions or projections on . said sheets or web material are placed, and b) at least one pressing member (10) or counter-pres- sing member (9a-9d) adapted to be secured to said base plate (6,5) by means of the securing means (8,7) and to work on the projection or projections (2a-2d) situated in a corresponding position on the starting material.

Inventors: JUUL NIELS, RASMUSSEN TORBEN, JUUL, NIELS, RASMUSSEN, TORBEN
Applicants: HARTMANN AS BRDR, BROEDRENE HARTMANN A/S
Application year: 1993
Main classification: B65D81
IPC codes: B31F1, B65D81