Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D5/00—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper
  • B65D5/20—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper by folding-up portions connected to a central panel from all sides to form a container body, e.g. of tray-like form
  • B65D5/2014—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper by folding-up portions connected to a central panel from all sides to form a container body, e.g. of tray-like form the central panel having a non rectangular shape
  • B65D5/2033—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper by folding-up portions connected to a central panel from all sides to form a container body, e.g. of tray-like form the central panel having a non rectangular shape polygonal having more than four sides, e.g. hexagonal, octogonal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D5/00—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper
  • B65D5/20—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper by folding-up portions connected to a central panel from all sides to form a container body, e.g. of tray-like form
  • B65D5/2038—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper by folding-up portions connected to a central panel from all sides to form a container body, e.g. of tray-like form at least two opposed folded-up portions having a non-rectangular shape
  • B65D5/2047—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper by folding-up portions connected to a central panel from all sides to form a container body, e.g. of tray-like form at least two opposed folded-up portions having a non-rectangular shape trapezoidal, e.g. to form a body with diverging side walls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D5/00—Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper
  • B65D5/42—Details of containers or of foldable or erectable container blanks
  • B65D5/56—Linings or internal coatings, e.g. pre-formed trays provided with a blow- or thermoformed layer
  • B65D5/563—Laminated linings; Coatings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2105/00—Rigid or semi-rigid containers made by assembling separate sheets, blanks or webs
  • B31B2105/002—Making boxes characterised by the shape of the blanks from which they are formed
  • B31B2105/0024—Making boxes having all side walls attached to the bottom
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2110/00—Shape of rigid or semi-rigid containers
  • B31B2110/10—Shape of rigid or semi-rigid containers having a cross section of varying size or shape, e.g. conical or pyramidal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2120/00—Construction of rigid or semi-rigid containers
  • B31B2120/40—Construction of rigid or semi-rigid containers lined or internally reinforced
  • B31B2120/402—Construction of rigid or semi-rigid containers lined or internally reinforced by applying a liner to already made boxes, e.g. opening or distending of the liner or the box
  • B31B2120/404—Construction of rigid or semi-rigid containers lined or internally reinforced by applying a liner to already made boxes, e.g. opening or distending of the liner or the box using vacuum or pressure means to force the liner against the wall
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2120/00—Construction of rigid or semi-rigid containers
  • B31B2120/40—Construction of rigid or semi-rigid containers lined or internally reinforced
  • B31B2120/402—Construction of rigid or semi-rigid containers lined or internally reinforced by applying a liner to already made boxes, e.g. opening or distending of the liner or the box
  • B31B2120/406—Construction of rigid or semi-rigid containers lined or internally reinforced by applying a liner to already made boxes, e.g. opening or distending of the liner or the box the lining material being a plunger, a web, a sheet or a bag to be forced into the box, e.g. by using heat

Definitions

• the invention relates to a cardboard tray folded out of a single sheet, which tray comprises:
• Such a cardboard tray is for example known from EP 2441697 .
• the upstanding wall is composed out of flat wall part sections, which extend from the bottom to the upper edge. As a result the angle between the bottom and the upstanding wall is close to 90°.
• the plastic foil When arranging the plastic foil into the folded cardboard tray, the plastic foil will stretch unevenly. In particular at the edges and corners of the cardboard tray the degree of stretch of the plastic foil is substantial compared to the other parts where the plastic foil is lined against the inside of the cardboard tray.
• the first upstanding wall part sections will have a larger angle with the bottom, compared to a prior art cardboard tray.
• Using at least a first and second wall part section for the upstanding wall allows for the edges and corners to approximate a curved edge or corner, in which the angles are less sharp.
• the plastic foil when lined into the cardboard tray will stretch more evenly, such that the thickness of the plastic foil at the edges between the bottom and first wall part sections as well as between the first and second wall part sections, is less reduced in relation to the thickness of the plastic foil at the remaining portions of the cardboard tray.
• the cardboard tray according to the invention can thus be manufactured lighter and at lower costs, than a cardboard tray according to the prior art.
• the angle between the normal vector of each first upstanding wall part section with the normal vector of the bottom is within the range of 15° - 60°, preferably within the range of 15° - 45°.
• the foil When the plastic foil is heated and lined against the inside of the cardboard tray, the foil will stretch the most at the edges with the bottom. Having the angle between the bottom and the first upstanding wall part section in the range of 15° - 60°, preferably within the range of 15° - 45° ensures that the variation of stretch in the plastic foil is substantially reduced.
• Another embodiment of the cardboard tray according to the invention further comprises a peripheral, horizontal flange arranged to the upper edge of the upstanding wall.
• a horizontal flange provides for additional strength to the cardboard tray and allows for sealing of a lid onto the flange, after the cardboard tray has been filled with for example food stuff.
• peripheral, horizontal flange is composed out of flange parts, which abut to each other and wherein the abutting parts have complimentary shapes, such as complimentary wave shapes or jigsaw puzzle piece connectors.
• a reduced thickness of the plastic foil could cause a weaker connection between abutting flange parts.
• By providing the abutting parts with complimentary shapes causes the flange parts to hook together providing for a connection between the flange parts. This connection will relieve the plastic foil, resulting in a stronger overall connection despite the thinner plastic foil.
• the length of the edges with which the flange parts abut to each other is longer than with a straight edge. Due to the thin plastic foil, the plastic foil could drop between the abutting edges, which makes it more difficult to seal a lid airtight. However, with the complimentary shape, the distance of the abutting edges is longer, which improves the chance that a lid will be sealed airtight onto the flange.
• the bottom has a polygonal shape, preferably an octagonal shape. Having a polygonal shape, such as an octagonal shape also reduces the sharpness of the angles between the edges of the bottom and accordingly of adjacent first upstanding wall part sections. This further reduces the amount in which the plastic foil is stretched when being laminated to the inside of the cardboard tray.
• a first upstanding wall part section is arranged along a first fold line.
• the heated plastic foil is pre-stretched by pulling the plastic foil into a heated dome before laminating the heated plastic foil against the inside of the cardboard tray.
• the plastic foil is stretched evenly by pulling the plastic foil into a heated dome.
• the plastic foil is then further stretched, when the foil is laminated into the cardboard tray.
• the extremes in stretching of the plastic foil will be reduced.
• the plastic foil By heating the plastic foil in zones differently, the plastic foil will stretch differently locally. This allows for more control on how the plastic foil is stretched when laminated into the cardboard tray.
• zones heated to a relative low temperature compared to the temperature of other zones of the plastic foil correspond with corners in the cardboard tray.
• the plastic foil typically tends to stretch the most, heating said parts of the plastic foil to a lower temperature, ensures that said portion will get less stretched and that other parts of the plastic foil will get stretched more, than when the plastic foil is heated evenly.
• Figure 1 shows a first embodiment of a cardboard tray 1 according to the invention.
• the tray 1 has an octagonal bottom 2 with along each straight edge an upstanding wall part 3, 4 composed out of a first upstanding wall part section 3 and a second upstanding wall part section 4.
• the upstanding wall parts 3, 4 form the upstanding wall having an upper edge 5 defining the access opening of the tray 1.
• the access opening is bordered by a horizontal flange 6 arranged arranged to the upper edge.
• Figure 2 shows a cross-section of the cardboard tray 1 according to figure 1 .
• the angle ⁇ is formed between the normal vector of the first upstanding wall part section 3 and the normal vector of the bottom 2.
• the angle ⁇ is formed between the normal vector of the cord 7, extending between the peripheral edge 8 of the bottom 2, bordering the respective first upstanding wall part section 3 and the upper edge 5, and the normal vector of the bottom 2.
• the angle ⁇ is smaller than the angle ⁇ , such that the upstanding wall part 3, 4 approximates a curved wall part.
• FIG 3 shows a perspective view of a second embodiment of a cardboard tray 20 according to the invention.
• the cardboard tray 20 has an octagonal bottom 21 with first upstanding wall part sections 22, 23 arranged on each straight edge of the octagonal periphery of the bottom 21.
• the first upstanding wall part sections 23 form corners, while the first upstanding wall part sections 22 are provided with second upstanding wall part sections 24, of which the upper edges 25 form a rectangular access opening.
• the access opening is bordered by a horizontal flange composed out of flange sections 26.
• each of the first upstanding wall part sections 22, 23 applies that the angle between the normal vector of each first upstanding wall part section 22, 23 with the normal vector of the bottom 21 is smaller than the angle between the normal vector of the cord, extending between the peripheral edge of the bottom 21 bordering the respective first upstanding wall part section 22, 23 and the upper edge 25, and the normal vector of the bottom 21. This corresponds to the angles as explained in figure 2 for the cardboard tray 1 shown in figure 1 .
• the upper mold 30 is heated, such that the plastic foil 31 is heated.
• the plastic foil 31 By pre-stretching the plastic foil 31 the plastic foil 31 is stretched evenly and when the foil 31 is lined into the cardboard tray 1, 20, the additional stretching is limited. This contributes, in addition to the shape of the cardboard tray 1, 20, to a more even thickness of the lined plastic foil 31 allowing for a reduction in thickness of the plastic foil 31 compared to the prior art.
• Figure 5 shows a schematic top view of a second embodiment of the method according to the invention.
• a heated plate 40 is used instead of the upper mold 32 with the dome shaped cavity 33 in the method shown in figures 4A-4C .
• the heated plate 40 had three concentric zones 41, 42, 43, of which the temperature can be controlled separately. This allows for the plastic foil to be heated in three different zones.
• FIG 5 a top view of a cardboard tray 1 according to figure 1 is shown.
• the first heating zone 41 corresponds with the bottom 2
• the second heating zone corresponds with the first upstanding wall part sections 3
• the third heating zone 43 corresponds with the second upstanding wall part sections 4 and the flange 6.
• the plastic foil being lined against the first upstanding wall part sections 3 is less flexible, such that the stretchability is reduced for this zone. This also contributes to a more even stretching of the plastic foil and allows for using a thinner plastic foil compared to the prior art.
• Figure 6A shows a cardboard tray 50 with a bottom 51, first upstanding wall sections 52 and second upstanding wall sections 53, similar to the cardboard tray of figure 1 and 2 .
• Horizontal flange parts 54, 55 are arranged to the upper edge of the upstanding wall 52, 53.
• the horizontal flange parts 54, 55 abut at the edges 56, which have a complimentary wave shape, such that the flange parts 54, 55 hook into each other.
• Figure 6B shows a further embodiment of a cardboard tray 60 with a bottom 61, first upstanding wall part sections 62, second upstanding wall part sections 63 and horizontal flange parts 64, 65.
• the abutting flange part sections 64, 65 are connected to each other by a jigsaw puzzle piece connector 66.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Containers Having Bodies Formed In One Piece (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=91898434

Family Applications (1)

Country Status (2)

Citations (7)

• 2024
  • 2024-07-08 EP EP24187134.2A patent/EP4678548A1/de active Pending
• 2025
  • 2025-05-19 WO PCT/EP2025/063691 patent/WO2026012636A1/en active Pending

Patent Citations (7)

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