CA2005705A1 - Waterproof box or cover blank - Google Patents

Abstract

Abstract A waterproof box or cover blank comprises a flat sheet (1) of non-waterproof corrugated paperboard, which has folding lines (6,7,8,9) and, if desired, incisions (2,3,4,5) for forming corner flaps (16, 17, 18, 19).
Blank (1) is on both sides covered by a waterproof plastic film (10, 11), which films are joined by welding outside the external edges of blank (1).
Plastic films (10,11) are loosely arranged, i.e. not attached to the flat sheet (1). Plastic films (10,11) are also bonded in slots (2, 3, 4, 5) and split centrally inside them, slots (2, 3, 4, 5) having a width to provide space for welding and slotting tools.

(Fig. 1).

Description

X~C~S7~5 The present lnvention relates to a waterproof box or cover blank comprising a flat sheet of a material that is not waterproof, e.g. corrugated cardboard, with folding lines 5 and, if desired, wlth incisions for forming flaps.

Such blanks are used to form a number of different kinds of boxes and crates. The blanks are transported ln the flat from the packing factory to the user and are mounted, often mechanically, at the user's place. Such boxes or crates which are produced from a non-waterproof material, cannot be used for moist goods or goods setting free moisture, and neither can they be used in a moist environment. Such blanks being inexpensive, many efforts have been made to make them ~5 waterproof, so that they may be used under conditions as mentioned above. There is, e.g. a great demand for packing material for fish to be transported in an iced state over long distances. Previously, such boxes were manufactured from expanded plastic, e.g. polystyrene. Such boxes are relatlvely 20 expensive ln manufacture, as well as being bulky in trans-port, since they cannot be manufactured in a flat state.
Nowadays, there is also considerable resistance in many countries against use of such packing material, because when destructed it gives off substances that may destroy the ozone 25 layer of the atmosphere. Experiments to make non-waterproof material waterproof involved lamination with a watertight film on both sides. However, no sealing of the edges is achieved, and the packing may thus be destroyed by water penetrating into it through the edges. Also, efforts were made to line such packing material by the aid of a bag-shaped lining whlch is attached to the folding sheet. Thls would, however, be an e~penslve measure, as well as being un-desirable to the user, as such a lining must be inserted after the box has been mounted.

As regards transport of fish, which is an important applicat-ion in connection with the present inventlon, boxes or crates 2 ~ 0~7 ~S

of the mentioned klnd, in which the flaps are formed by the aid of slots or lnclsions, can only be used in cases when lt is acceptable that water seeps from the crates. Such a packing cannot be waterproof as water may flow through sald slots. For the tlme being, such packlngs are permltted for transport on trucks, in splte of the fact that quite considerable volumes of water may leak from one single crate.
In thls connectlon, lt should be mentloned that approximately 4-7 kgs of lce are used ln a flsh crate and in the worst case o all ice may melt during transport. A truck driving with such a load would, thus, sprinkle thousands of litres of water on the road, whlch may make the road surface slippery. It is, thus, to be expected that such transport will be prohibited ln the future. As regards alr frelght, packings must be completely tight. No leakage of l~quld ls permitted from goods transported by alr. Packing crates used for flsh for air frelght comprlse an external waterproof box wlth a perforated double bottom and an absorbing materlal provlded between sald double bottom and the external bottom of the 20 box.

It is an obJect of the present invention to provlde a waterproof crate or cover blank, based on a flat sheet of a non-waterproof material, e.g. corrugated paperboard wlth 25 foldlng llnes and, lf deslred, incisions forming flaps, out of whlch blank a box or a crate may be mounted.

Accordlng to the lnventlon thls ls achleved by the fact that sald blank i8 on both ældes coated by a waterproof plastlc 30 fllm, which fllms are Jolned by weldlng outslde the external edges of the blank, and by the fact that sald plastlc fllms are loosely arranged, l.e. not attached to the flat sheet of non-waterproof materlal.

35 By means of the lnventlon several advantages are obtalned.
Prlmarlly the productlon of the blank wlll be lnexpenslve.

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Because the plastic films are loosely arranged outside of the blank, a good thermic insulation ls obtalned in that a layer of air is formed between the plastlc film and the corrugated paper board blank. A second essentlal advantage obtained by 5 the fact that the plastlc film ls loose in relation to the corrugated paper board, consist in easy removal of the plastic fllm for recirculation or destruction by means of fire.

o A special embodiment in which the blank ls provided with incisions or slots to form flaps, is characterized by the fact that the plastic films are also welded together in the incisions or slots and split centrally in the slot, said slots having such a width that there is space enough for 15 welding and slotting tools.

Futher features of the invention will appear from dependent claims 2-5.

20 The invention is disclosed in more detail below with reference to the drawings showing embodiments of the invention.

Flgure 1 shows a plane blank according to the invention, which is intended for mounting a cover, Figure 2 is a section along line Il-II in Figure 1, Figure 3 shows the blank in an mounted state in the form of a fish crate, Figure 4 shows a section of a box or cover blank of ` 30 another kind, Figure 5 shows a corner of a box or cover which ls mounted from the blank of Figure 4, and Figure 6 shows a flat blank intended for belng mounted to form a box.

A plane sheet of a non-waterproof material 1, in this embodiment conslstlng of corrugated paperboard, is provided . - : : .. .. ~ , : . ~:
.

Z ~ ~ ~J~ ~ 5 with slots 2, 3, 4, and 5 at two opposite longltudinal sldes, and with longitudinal folding lines 6 and 7, and transverse folding lines 8 and 9. Sheet 1 is on both sides coated by a plastic film 10, and 11, respectivel~. The plastlc films are slightly larger than sheet 1 to form a proJecting rim 12 outslde the edge of sheet l. ~dges 12 of fllms 10 and 11 are bonded so that sheet 1 is placed ln~ide a watertlghtly sealed bag. Incisions or slots 2, 3, 4, and 5 are wide enough to provide space for welding tools, and a double weld 13, 14 is provlded ln the plastic materlal lnside the slots. Between welds 13, 14 a slot 15 is provided in the plastic material.

Flgure 3 shows a box or crate mounted from the blank of Figure 1. Corner flaps 16, 17, 18, and 19 are folded inside ~5 the end flaps, and corner flaps and end flaps are are Joined by the aid of staples 20. A corresponding box may be manufactured by the ald of a blank, ln which slots extend inwards from the edges at the ends.

20 Figure 4 shows a section of a waterproof box or crate blank which, in the same manner as disclosed in connection wlth Figure 1, conslsts of a sheet 21 of a non-waterproof material, which is on both sides coated by a plastic film 22, 23, the films being bonded at the edges 24 by the aid of a 25 weld 25. This blank has no slots or incisions. It ls only provlded with foldlng llnes 26 and 27 extending ln parallel with the edges of the sheet, and a diagonal folding llne 28 for forming a corner, as shown in Figure 5. The corner flap formed by folding lines 26, 27 is folded to form an inclined 30 fold about folding llne 28. In thls manner completely ~; waterproof corner Joints are achieved ln the box.

As wlll appear from Figure 1 of the drawing, slots 2, 3, 4, 5 extend into the blank past the longitudinal folding lines 35 6,7. In a folded box this extension will form drainage openings at the corners of the bottom. It will aslo appear from Figure 1 and the enlarged detail that slots 2, 3, 4, 5 - : ~

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are displaced relatlve to transverse folding llnes 8, 9, so that the pro~ections of said foldlng lines extend adJacent to the edge of the slots facing corner flaps 16, 17, 18, 19. The reason for this ls that in this manner only a minimum of the materlal of the corner flaps ls removed. Most of the blank material which has vertical corrugations in a mounted state and is, thus, most sulted to absorb loads, will thus be maintained.

o Figure 6 illustrates a blank 1 for mounting a crate or a box. As will appear from the drawing, slots 2, 3, 4, and 5 extend inwards from the short sides of the blank, as opposed to the blank of the cover, as shown in Figure 1, in which the slots extend inwards from the long sides of the blank. Both in Figure 1 and in F~gure 6 the directions of corrugations of the corrugated paperboard are indicated. In both cases the directions of corrugations is transversal to the longitudinal direction of slots 2, 3, 4, 5. When the cover of Figure 1 is mounted, corner flaps 16, 17, 18, 19 are folded along the 20 longitudinal sides of the blank, whereas flaps 16, 17, 18, 19 in the crate blank are folded along the short sides. In this manner three plies of paperboard are provided at the short sides, and almost the same in the longitudinal sides, dependent on the length of the longitudinal sides relative to 25 the short sides. Corrugated paperboard has good insulating properties, and by coating the paperboard with tight layers on both sides insulation properties are further improved. By folding the flaps as mentioned above, very good insulation is achieved.
~o By choosing the direction of corrugation as explained above relative to the folding of corner flaps, corners havlng vertlcal corrugatlons in several plles are achleved. Thls provldes packings whlch have a good capability of absorbing 35 vertical loads. The same is true of the embodiment according to Figures 4 and 5.

Claims (5)

1.
A waterproof box or cover blank comprising a flat sheet (1) of corrugated paperboard which has folding lines (6, 7, 8, 9), and incisions (2, 3, 4, 5) forming corner flaps (16, 17, 18, 19), c h a r a c t e r i z e d i n that blank (1) is on both sides provided with a waterproof plastic film (10,11) which films are Joined by welding outside the external edges of the blank, and that the waterproof plastic film is loosely arranged i.e. not attached to the flat sheet is of a non-waterproof material.

2.
A box blank as stated in claim 1, c h a r a c t e r i z e d i n that plastic films (10, 11) are bonded in slots (2,3,4,5) and spilt centrally in the slots, said slots having a width which is sufficient for welding and slotting tools.

3.
A box blank as stated in claim 1 or 2, c h a r a c t e r 1 z e d i n that the corrugations of the corrugated paperboard extend transversal to the direction of incisions

4.
A box blank as stated in claim 2, c h a r a c t e r -i z e d i n that slots (2,3,4,5) are displaced relative to the transversal folding lines (8,9), so that the project-ion of the folding lines is adjacent to the slot edge which is present at the corner flaps (16, 19, or 17, 18).

5.
A box blank as stated in one of a number of the preceding claims, c h a r a c t e r i z e d i n that slots (2,3,4,5) project a distance inside the folding lines (6,7) extending in parallel with the lateral edges of the sheet.