GB2632017A

GB2632017A - Thermally insulated folding carton

Info

Publication number: GB2632017A
Application number: GB2311270.9A
Authority: GB
Inventors: Midgley Stephen; Mizerska Dagmara
Original assignee: John Cotton Group Ltd
Current assignee: John Cotton Group Ltd
Priority date: 2023-07-21
Filing date: 2023-07-21
Publication date: 2025-01-22
Also published as: GB202311270D0

Abstract

A blank assembly 100B for a thermally insulated folding carton (100A fig. 1A) comprising: a folding carton blank 110 for forming into a formed carton having carton sides, a first end for the insertion of contents into the carton, and an opposed carton second end. The formed carton having interior surfaces and exterior surfaces; and one or more flexible thermally insulating members 120, connected to one or more interior surfaces of respective carton sides. There may be a plurality of thermally insulating members, bonded to the interior surface of the carton sides. The carton may be formed from cellulosic card, fibreboard, or paperboard. The carton may be rectangular cuboidal. Further disclosed is a method of forming a blank assembly for a thermally insulating folding carton. Additionally disclosed is a thermally insulating member comprising a pulp mat between first and second sheet layers, the pulp mat having tapered edge regions that reduce towards the edges of the mat, and a corresponding method.

Description

THERMALLY INSULATED FOLDING CARTON

TECHNICAL FIELD

The present invention relates to thermally insulating packaging, and more particularly, but not exclusively, to thermally insulating packaging for use in the storage and transport of foodstuffs, horticultural products and pharmaceuticals.

BACKGROUND

Thermally insulating packaging is used in transporting chilled foodstuffs, pharmaceuticals, heated foodstuffs, and other temperature sensitive products.

For high thermal performance applications, users may need to maintain the temperature of frozen goods below 0°C for 24 hours to 48 hours, when exposed to particular ambient conditions (e.g. 24°C). In use, frozen goods may also be enclosed within the thermally insulating packaging with an ice pack.

Current thermally insulating packing for high thermal performance applications is commonly made from expanded polystyrene (EPS), which may additionally be placed into a separate cardboard box. Expanded polystyrene is not generally recyclable, and instead it is commonly disposed of as household landfill waste.

SUMMARY OF THE DISCLOSURE

According to the present disclosure, there is provided a blank assembly for a thermally insulated folding carton and a method of forming the blank assembly, a partially formed blank assembly and a method of forming the partially formed blank assembly, and a thermally insulated folding carton.

According to a first aspect, there is provided a blank assembly for a thermally insulated folding carton comprising: a folding carton blank for forming into a formed carton having carton sides, a carton first end for the insertion of contents into the carton, and an opposed carton second end, the formed carton having interior surfaces and exterior surfaces; and one or more flexible thermally insulating members connected to one or more interior surfaces of respective carton sides.

According to a second aspect, there is provided a partially formed blank assembly comprising the blank assembly of the first aspect, wherein carton sides of the folding carton blank have opposed edges that are connected together to form a tubular assembly of carton sides.

According to a third aspect, there is provided a thermally insulated folding carton comprising the blank assembly of the first aspect, or the partially formed blank assembly of the second aspect, wherein the folding carton blank is formed into a pre-formed carton.

According to a fourth aspect, there is provided a method of forming a blank assembly for a thermally insulated folding carton comprising: forming a folding carton blank for forming into a formed carton having carton sides, a carton first end for the insertion of contents into the carton, and an opposed carton second end, the formed carton having interior surfaces and exterior surfaces; and connecting one or more flexible thermally insulating members to one or more interior surfaces of respective carton sides.

According to a fifth aspect, there is provided a method of forming a partially formed blank assembly comprising connecting together opposed edges of carton sides of the folding carton blank of the fourth aspect to form a tubular assembly of carton sides.

According to a sixth method, there is provided a blank assembly for a thermally insulated folding carton, a partially formed blank assembly for a thermally insulated folding carton or a thermally insulated folding carton formed by the method of the fourth aspect or the fifth aspect.

According to a seventh aspect, there is provided a thermally insulating member comprising a pulp mat between first and second sheet layers, wherein the pulp mat has one or more tapered mat edge regions, and in each adjacent tapered mat edge region the thickness of the pulp mat has a tapered thickness profile that reduces towards a respective edge of the pulp mat.

According to an eighth aspect, there is provide a method of forming a thermally insulating member comprising a pulp mat between first and second sheet layers, wherein the pulp mat has one or more tapered mat edge regions, and in each adjacent tapered mat edge region the thickness of the pulp mat has a tapered thickness profile that reduces towards a respective edge of the pulp mat, the method comprising compressing an edge region of a pulp mat to form the tapered mat edge region having the tapered thickness profile.

According to a ninth aspect, there is provided a thermally insulating member formed by the method of the eighth aspect.

The blank assembly may comprise a plurality of the thermally insulating members connected to interior surfaces of respective carton sides.

A thermally insulating member may be bonded to the interior surface of each carton side.

The one or more thermally insulating members may be configured to provide, in use, at least one layer of thermally insulating member between a product within the carton and the interior surfaces of the carton first end and the carton second end.

Each of the one or more thermally insulating members may be connected to the interior surface of the carton sides in a second region adjacent the carton second end, and may not be connected to the interior surface of the carton sides in a first region adjacent the carton first end.

The carton has a height extending between the carton first end and the carton second end, and the first region may extend up the carton side by at least 25% of the height.

The first region may extend up the carton side by at least 40% of the height.

The one or more thermally insulating members may each comprise a pulp mat between first and second sheet layers.

The pulp mats of adjacent thermally insulating members may have adjacent tapered mat edge regions, and in each adjacent tapered mat edge region the thickness of the pulp mat may have a tapered thickness profile that reduces towards a respective edge of the pulp mat.

In the tapered mat edge region(s), one side of the pulp mat may be provided with a bevelled surface and the other side of the pulp mat may be flat.

The pulp mat may be a cellulosic pulp mat.

The sheet layers may be cellulosic sheet layers.

An adhesive may bond together the first and second sheet layers within a margin around the periphery of the sheet layers.

The first and second sheet layers may be stitched together with thread within a margin (M) around the periphery of the sheet layers.

The carton blank may be formed from cellulosic card stock, corrugated fibreboard, or paperboard.

The formed carton may be a rectangular cuboidal formed carton.

The one or more thermally insulating members may each comprise a pulp mat between first and second sheet layers, wherein the pulp mats of adjacent thermally insulating members may have adjacent tapered mat edge regions, and in each adjacent tapered mat edge region the thickness of the pulp mat may have a tapered thickness profile that reduces towards a respective edge of the pulp mat, and the method may comprise compressing an edge region of a pulp mat to form the tapered mat edge region having the tapered thickness profile.

Compressing the tapered edge region of the pulp mat may comprise compressing with a bevelling roller.

Compressing with the bevelling roller may comprise forming an adhesive bond between the first and second sheet layers.

The various embodiments described above represent individual features of the invention which can be applied generally to the system of the invention. These features may be taken individually as preferred features or more than one of these preferred features may be combined with one another in any combination.

DESCRIPTION OF THE DRAWINGS

Examples are further described hereinafter with reference to the accompanying drawings, in 35 which: * Figure 1A shows a thermally insulated folding carton in the pre-formed state; * Figure 1B shows the thermally insulated folding carton of Figure 1A, after it has been partially filled; * Figures 1C and 1D a show plan view and a cross-sectional view of a blank assembly for forming the thermally insulated folding carton of Figure 1A; * Figure 1E shows a partially formed blank assembly for forming the thermally insulated folding carton of Figure 1A, in a collapsed state; * Figure 1F shows a cross-sectional view through the partially formed blank assembly of Figure 1E; * Figure 1G shows a plan view of a partially assembled blank assembly of Figure 1C; * Figures 1H and 11 show a plan view and a cross-sectional view of a further blank assembly for forming a further thermally insulated folding carton, and Figure 1J shows an enlarged view of part of Figure 11; * Figures 2A and 2B show a cross-sectional view and a plan view of a thermally insulating member; * Figures 3A and 3B show methods of forming a tapered edge region of a pulp mat with a bevelling roller; * Figure 3C shows a cross-sectional view of a thermally insulating member formed with the pulp mat manufactured by the process of shown in Figure 3A; and * Figures 3D and 3E respectively show the corner of a thermally insulated folding carton formed with thermally insulating members as shown in Figure 3B, in a pre-formed state and in a partially formed, collapsed state.

DETAILED DESCRIPTION

Like reference numerals refer to like elements throughout. In the described examples, like features have been identified with like numerals, albeit in some cases having one or more of: increments suffix letters. For example, in different figures, 100, 100A, 100B and 100C have been used to indicate a thermally insulated folding carton and blank assemblies for forming a thermally insulated folding carton The present application concerns thermally insulated folding cartons that may provide high thermal insulation performance and may resist impacts during use as a formed carton for packaging contents. The construction may enable a thermally insulated folding carton that can be readily recyclable with current curb-side recycling in many countries.

The thermally insulated folding carton 100, may be supplied in different states 100A, 100B, 100C, subject to user requirements, as shown in Figures 1A to 1J. In the pre-formed state, the thermally insulated folding carton 100A has a pre-formed folding carton 110 lined by one or more flexible thermally insulating members 120. The one or more flexible thermally insulating members 120 may each be a thermally insulating wrap.

The thermally insulated folding carton 100 may be provided in the pre-formed state 100A, as shown in Figure 1A, ready to receive contents through the open top, at the first end 100E1, before being closed. Figure 1B shows the pre-formed thermally insulated folding carton 100A after it has been partially filled, and the thermally insulating members 120 have been closed over the contents, prior to the flaps 110F1 being closed to complete closure of the carton 110. Being supplied in the pre-formed state 100A enables the most rapid use, by avoiding the need for prior formation of the thermally insulated folding carton 100A by a user who is using the thermally insulated folding carton to package contents.

Alternatively, the thermally insulated folding carton may be provided as a blank assembly 100B (e.g. flat), ready for assembly by the user, as shown in Figure 10, prior to formation as the formed thermally insulated folding carton 100A shown in Figure 1A. Figure 10 shows a cross-sectional view through the bank assembly 100B of Figure 10 along the line E-E. Being supplied as a blank assembly (e.g. in a flat state) enables the greatest number of thermally insulated folding cartons to be supplied for a given volume of shipment.

In a further alternative, the thermally insulated folding carton 100 may be provided in an intermediary state, as a partially-formed blank assembly 100C that has been partially formed and remains in a collapsed state (also known as a knocked-down state), as shown in Figures 1 E and 1F. Figure 1F shows a cross-sectional view through the partially-formed blank assembly 100C of Figure 1 E along the line F-F. Being supplied in a collapsed state enables a larger number of thermally insulated folding cartons to be supplied for a given volume of shipment compared with pre-formed thermally insulated folding cartons 100A, whilst requiring only a small number of simple steps by the end user to complete formation of the thermally insulated folding carton 100A before it is ready to be filled with goods (e.g. requiring only closure and securing at the second end 100E2, considerably simplifying formation by a user compared with the user completing the formation from blank assemblies 100B (e.g. from a flat state).

Figure 1G illustrates the formation of the blank assembly 100B of Figure 1C, showing the blank assembly in a partially assembled state, with two thermally insulating members 120 connected on the part of the flat carton blank 110B in the left of the drawing, and with two further thermally insulating members 120 yet to be connected to another part of the carton blank 110B, on the right.

In Figures 10, 1D and 1G, adjacent thermally insulating members 120 are positioned on the carton blank 110B so that they abut and contact each other once the thermally insulated folding carton 100A has been fully formed, to impede air flow between them.

As shown in Figures 1H and 11, adjacent thermally insulating members 120' may be positioned on the carton blank 110B so that they overlap and press against each other once the thermally insulated folding carton 100A has been fully formed, to further impede air flow between them. Figure 1J shows an enlarged view of part J of Figure 11. The sheet layers 124 of each thermally insulating members 120' may extend into a margin M (similarly to Figures 2A and 2B) around the pulp mat 122. Adjacent thermally insulating members 120' may be positioned so that the margins M overlap the adjacent thermally insulating member 120' in the blank assembly 100B. The adjacent thermally insulating members 120' may be positioned so that the adjacent pulp mats 122 abut in the blank assembly 100B.

The blank assembly 100B is formed by cutting a carton blank 110B from sheet material and connecting one or more thermally insulating members 120 to the carton blank 110B. The carton blank 110B is cut as a pattern of panels, and is provided with folds 112 between the directly connected panels 110S, 110F. As well as panels for forming the sides 110S of the carton 100A, other panels provide hinged flaps 110F1, 110F2 for folding together for forming respective ends 110E1, 110E2 of the carton. The carton blank 110B may be cut with a different pattern of panels.

The folds 112 may be formed by creasing or scoring.

The carton blank 110B may be cut from cellulosic card stock, corrugated fibreboard (e.g. a fluted corrugated sheet and at least one linerboard), or paperboard (e.g. paper with a grammage above 250 g/m2).

The carton blank 110B may have a sealing tab 110T extending from the edge of a panel forming a side 110S, for securing to a portion 100V of an opposed panel forming another side 110S of the folding carton 110, when forming the blank assembly 100B into the partially formed blank assembly 100B, in the collapsed state. The sealing tab 110T may be secured with adhesive or adhesive tape.

Alternative securing structures may be used, for example with the opposed edges of opposed sides 110S of the folding carton 110 being secured together by adhesive tape without a sealing tab 110T, or may be stitched with thread.

The one or more thermally insulating members 120 (similarly 120' and 120B) are connected to the carton blank 110B by adhesive 130, on the surfaces that will be interior surfaces of the formed folding carton 110. The adhesive 130 may be provided as lines of adhesive 130A, 130B, 130C or larger areas or alternative patterns of adhesive.

The thermally insulating member(s) 120 may be connected to the carton blank 110B by an alternative connection, including stitching, clips or hook-and-loop fasteners.

When formed, the formed folding carton 110 has a height HO, extending between a first end 110E1 and a second end 110E2, e.g. the length of the side 110S of the folding carton 110. The one or more thermally insulating members 120 may be connected to the interior surfaces of the sides 110S of the folding carton 110 in a second region H2 proximate the second end face 110E2 (e.g. adhesive lines 130A, 1308, 130C), and a first region H1 of the interior surfaces of the sides 110S may be free of connection between the thermally insulating member(s) and the folding carton 110. The first region H1 may be at least 20%, or at least 30%, e.g. 33%, of the height HO of the formed carton 110.

When the thermally insulated folding carton 100A is in use, having the first region H1 of the interior surface of the sides 110S of the folding carton 110 in which the thermally insulating member(s) 120 are not connected to the folding carton 110 enables the thermally insulating members 120 to be folded down closely across the top of the contents of the package when it is not completely filled (e.g. two-thirds filled). Being folded closely across the top of the packaged contents improves thermal insulation of the packaged contents, including by reducing convection currents of air above the contents, compared with the thermally insulating members 120 being connected to the interior surface of the first end 100E1 of the thermally insulated folding carton 100A, in particular when the packaged contents only partially fill the thermally insulated folding carton 100A.

Alternatively, the thermally insulating members 120 may be connected proximate both the first and second ends 110E1, 110E2 of the sides 110S of the folding carton 110, e.g. by lines of adhesive or by an alternative pattern of adhesive.

The adhesive 130 may be a holt melt glue, for example, ethylene-vinyl acetate (EVA) glue (e.g. ADMELT® 7591G from A.D. System Limited). The adhesive retains some flexibility in use, to avoid cracking when the thermally insulated folding carton 100 is used to package frozen or chilled goods.

A plurality of thermally insulating member 120 may be connected to the folding carton 110 to provide thermal insulation between the packaged contents and the sides 110S and ends 110E1, 110E2 of the folding carton 110, in use. For example, as shown in Figures 1A to 1F, a separate thermally insulating member 120 may be connected to the interior surface of each side 110S of the folding carton 110 (e.g. one thermally insulating member 120 is connected to the interior surface of each of four sides 110S of the folding carton 110). Such an arrangement may use generally rectangular thermally insulating members 120, as shown in Figure 10, which have lower manufacturing complexity.

Alternatively, thermally insulating members may be provided that are each connected to more than one panel of the folding carton 110, e.g. being connected to two adjacent sides 110S.

In a further alternative, a thermally insulating member may be provided that is connected to more than one panel of the folding carton, and which provides insulation between the packaged contents and each of the sides 110S and ends 110E1, 110E2 of the folding carton 110, in use.

For example, the thermally insulating member may extend across all of the sides 110S and have flaps for covering the contents of the thermally insulated folding carton 110A, in use.

A thermally insulating member 120 connected to a side 110S of the folding carton 110 may extend EX1, EX2 beyond the ends 110E1, 110E2 of the side 110S, across part or substantially all of one or both hinged flaps 110F1, 110F2 connected to the side 110S, as shown in Figure 1C.

The thermally insulating members 120 may extend EX1, EX2 beyond one or both of the first end 110E1 and the second end 110E2 (in the blank assembly 100B) sufficiently to meet the thermally insulating member 120 connected to the opposed side 110S of the formed thermally insulated folding carton 100A when in use and full of packaged contents, e.g. extending EX1, EX2 beyond one or both of the respective ends 110E1, 110E2 respectively by at least half the length L or width W of the formed thermally insulated folding carton 100A. The one or more thermally insulating members 120 may extend EX1, EX2 beyond the first end 110E1 and the second end 110E2 by the full length H3, H4 of respective hinged flap 110F1, 110F2, as shown in Figure 1G.

By extending EX1, EX2 beyond the respective end 110E1, 110E2 by at least half the length L or width W of the formed thermally insulated folding carton 100A, the thermally insulating members 120 may overlap to form at least a double layer across the base beneath the packaged contents, and may overlap to form at least a double layer over the packaged contents even when the thermally insulated folding carton 100A is full of packaged contents.

The one or more thermally insulating members 120 may extend beyond the second ends 110E2 of the sides 110S of the folding carton 110 to form at least a double layer of thermally insulating members 120 between the closed second end 110E2 of the folding carton 110 and the packaged contents of the thermally insulated folding carton 100A, in use, as shown in Figure 1A.

A thermally insulating member 120 is vulnerable to compression under the weight of contents packaged within the thermally insulated folding carton 100, in use, reducing its thermal insulation performance. The at least double layer may enhanced thermal insulation beneath the packaged contents, when the second end 110E2 of the thermally insulated folding carton 100A is used as the base upon which the packaged contents rest, in use.

The one or more thermally insulating members 120 may extend beyond the first ends 110E1 of the sides 110S of the folding carton 110 sufficiently to form at least a double layer across the packaged contents of the thermally insulated folding carton 100A, in use, when the thermally insulated folding carton 100A is full (Figure 1B shows a double layer across the packaged contents when the thermally insulated folding carton 100A is almost full).

The packaged contents may be vulnerable to draughts by convection where a thermally insulating member is laid over the packaged contents under its own weight, especially if the thermally insulated folding carton 100A is not full, and if the top of the packaged contents is uneven, or the packaged contents shifts during use (e.g. when handled, or if transported in a vehicle across an uneven road surface). The at least double layer may reduce air circulation at the top of the packaged contents and so enhance thermal insulation of the packaged contents when the first end 110E1 of the thermally insulated folding carton 100A is uppermost, in use.

The one or more flexible thermally insulating members 120 formed from a cellulosic pulp mat 122 between cellulosic sheet layers 124. Figure 2A shows a cross-sectional view, and Figure 2B shows a plan view of a thermally insulating member 120, formed from an assembly of cellulosic paper pulp mat 122 sandwiched between cellulosic sheet paper layers 124. Figure 2A corresponds to the cross-section indicated by line A-A in Figure 2B.

The cellulosic pulp mat 122 may be a cellulosic paper pulp mat. The cellulosic pulp mat 122 may substantially comprise cellulosic fibres from wood pulp, e.g. they may each comprise at least 90%wt cellulosic wood pulp fibres, at least 95%wt cellulosic wood pulp fibres, or substantially 100%wt cellulosic wood pulp fibres.

The pulp mat 122 is formed from fibres and traps air between its fibres, providing enhanced thermal insulation (e.g. compared with a corresponding mass of fibres formed into sheet material, e.g. formed into paper). The fibres of the pulp mat 122 may be air laid, which provides enhanced trapping of air between the laid fibres, and enhances the volume (provides bulk), providing enhanced thermal insulation. The air laid fibres provide a low density pulp mat 122, providing enhanced thermal insulation with a low mass.

The pulp mat 122 may have a volumetric mass density of 20-50 kg/m3, or 30-50 kg/m3. The pulp mat 122 may have a volumetric mass density that is lower than the volumetric mass density of the sheet layers 124 by at least 20%, or at least 30%.

The pulp mat 122 may have a thickness of at least 15mm, or at least 20mm. The paper pulp mat 110 may have thermal conductivity of 0.015 to 0.050 W/(m.K), or of 0.025 to 0.035 W/(m.K).

The sheet layers 124 extend beyond the periphery of pulp mat 122, being provided with a margin M around the pulp mat, from which the pulp mat is absent.

Within the margin M, the sheet layers 124 are bonded together in a seal 126 by an adhesive, forming a seal surrounding the pulp mat 122, substantially containing any loose fine particulate from the pulp mat 122 between the sheet layers, and preventing the contamination of products that are being thermally insulated by the thermally insulating member(s) 120 (or contamination of the surrounding environment), in use.

The adhesive in the seal 126 may be a holt melt glue, for example, ethylene-vinyl acetate (EVA) glue (e.g. ADMELT® 7591G from A.D. System Limited).

Instead of being bonded together with an adhesive 126, the sheet layers 124 of the thermally insulating member 120 may be sewn together to form a seal 126 in the margin M around the pulp mat 122 by stitching with a thread that passes through the sheet layers 124.

Where stitching is used, the thread may be a cellulosic fibre thread, e.g. cotton. The cellulosic fibre thread may be recycled through domestic paper recycling or composting. Alternatively, the thread may be polyester, or a mix of polyester and cellulosic fibres (e.g. a polyester-cotton blend). The thread may be less than 1% of the mass of the thermally insulating member 120.

The stitching (e.g. overlock stitching) may have stitch density of 200 to 400 stitches/m (approximately 5 to 10 stitches per inch). This range of linear stitch densities may enable the manufacture of robust thermally insulating packaging that resists water leakage and water penetration. More closely spaced stitches may substantially weaken the paper layers of the thermally insulating members 120, when the thermally insulating folding carton is used. More closely spaced stitches may increase the transmission of water, through the cellulosic thread, into the inner paper layers, reducing the thermal insulation performance of the thermally insulation folding carton. More widely spaced stitches may enable water within a thermally insulating folding carton to leak between cellulosic sheet layers 124 to the cellulosic pulp mat 122.

The areal mass density of the sheet layers 124 may be 40 to 100 g/m2. The volumetric mass density of the sheet layers 124 may be 500 to 1000 kg/m3, or 600 to 900 kg/m3.

The sheet layers 124 may be cellulosic sheet layers, e.g. each comprising cellulosic fibres from wood pulp, e.g. at least 90% cellulosic wood pulp fibres at least 95%wt cellulosic wood pulp fibres, or substantially 100%wt cellulosic wood pulp fibres.

The sheet layers 124 may be a light-weight kraft paper or paperboard (cardboard), which is more rigid that typical writing paper, whilst still able to flex and crease without fracture.

Where the sheet layers 124 are cellulosic paper, the heavier-weight sheet layers 124 provide a moisture barrier that protects the inner sheet layers 124B from moisture damage when the thermally insulated folding carton 100A is in use. The sheet layers 124 may absorb moisture within the thermally insulated folding carton 100A in use, for example absorbing condensation transferred from packaged frozen goods, or absorbing moisture from defrosting ice blocks. Cellulosic sheet layers 124A with a higher volumetric mass density may have a more tightly packed fibre structure, which may better resist penetration by moisture, during use (e.g. 24 to 48 hours), relative to a thicker paper with the same areal mass density. Cellulosic sheet layer 124A with a higher areal mass density may resist penetration by moisture for longer. Additionally, the heavier-weight sheet layers 124 facing the packaged contents of the thermally insulated folding carton 110A, in use, protects the inner sheet layers 1246 from mechanical damage during in use.

At least one of the cellulosic paper layers may be provided with a waterproof coating.

Advantageously, by construction from substantially cellulosic materials, the thermally insulating thermally insulated folding carton 100A may be recycled through domestic paper recycling or domestic composting, providing a lower environmental of footprint than existing rPET thermally insulating packaging, both in manufacturing and in end of life disposal.

The pulp mat 122 may be formed from airlaid cellulosic fibres, which may be formed from milled paper or paperboard (cardboard), for example recycled paper or paperboard.

The cellulosic pulp fibres for forming the pulp mat 122 may be produced by feeding virgin or recycled cellulosic material, such as paper or cardboard, into a hammer mill, where hammers are spun at high-speed and impact the cellulosic material, breaking apart the structure into fibres, pieces of material and fine dust-like material. The cellulosic material may be cut into pieces before being fed into the hammer mill.

A hole screen (e.g. a metal hole screen), for the passage of fibres, may be used to separate milled fibres and fine particulate from larger pieces of material. Finer, dust-like particulate may be removed from the passed material by separation with a fine filter.

At least 70%wt of the cellulosic fibres within the pulp mat 110 have a fibre length range of 3mm to 15mm (e.g. at least 80%wt or at least 90%wt of the fibres are within this range). A greater proportion (by mass) of fibres having a shorter fibre length would form a more densely packed pulp mat, when deposited, with a reduced proportion of micro-pockets of air within the pulp mat. A greater proportion (by mass) of fibres above this length range would be more difficult to process for air laying, and would result in less cohesion between fibres, which may result in a pulp mat that could deteriorate in handling, and may produce an uneven pulp mat, impairing thermal insulation performance (e.g. with areas of reduced air entrapment between the fibres of the pulp mat providing inefficient hotspots).

The cellulosic fibres within the pulp mat may comprise a mixture of first fibres and second fibres, wherein the average length of the second fibres is longer than the average length of the first fibres. A hole screen (or a plurality of separate hole screens) may be used that has a mixture of first holes and second holes, respectively having a smaller and a larger maximum dimension (e.g. diameter), for passing the first fibres and second fibres.

At least 70%wt (e.g. at least 80%, or at least 90%) of the cellulosic fibres within the pulp mat may have a fibre length within either a first fibre length range of 3mm to 8mm or within a second fibre length range of 10mm to 15mm.

The relative numbers of first and second holes in the hole screen may be selected to provide a mixture of fibre lengths in which at least 20%wt of passed fibres have the first fibre length, and at least 20%wt of passed fibres have the second fibre length range.

Before passing into an airlaying tower for deposition, the milled fibres may be dampened, to provide fibres having a mean average of 5 to 8% water by mass (when assembled into the thermally insulating packaging 100). For example, the fibres may be dampened by spraying with water as they are spun through a vortex sprayer, not shown, which produces a relatively uniform coating onto the exterior fibres, producing corresponding dampening of the fibre. Dampness in this range enhances mechanical bonding of the deposited fibres, when forming the pulp layer. In contrast, a greater proportion of water may produce a more dense pulp layer, and may be susceptible to the growth of mould or bacterial within the assembled thermally insulating packaging.

The cellulosic fibres may be deposited through an airlaying tower, for example by allowing the fibres to deposit onto a mesh conveyor belt with low pressure air flowing down through the mesh (e.g. a gentle air flow may be provided to blow the fibres through the airlaying tower, and onto the conveyor belt). Deposition of the fibres under a low pressure air flow enables a pulp layer to be built-up with a low density (i.e. enhanced "loft") by the incorporation of micro-pockets of air. The pulp layer is cut into separate pulp mats 122.

Before assembly between the sheet layers 124, the pulp mats 122 (or the pulp layer, prior to cutting into separate pulp mats) may be gently compressed (e.g. by passage between compression rollers) to enhance bonding between the dampened cellulosic fibres (e.g. by hydrogen bonding between the dampened surfaces of the fibres, where they are in physical contact), providing a pulp layer (from which the pulp mat 110 is cut) that is more resilient both during manufacture and when the thermally insulating packaging is in use. The pulp layer may be compressed by up to 60% of the pre-compressed thickness TD of the pulp mat. The compressed pulp mat 110' may be compressed to a thickness TC that is 50-67% of the deposited thickness TD.

Before assembly between the sheet layers 124, one or more edge regions (e.g. each edge region) of each of the pulp mats 122B may be compressed to form tapered edge regions 144 having a tapered thickness T that reduces towards the edge of the pulp mat 122B (e.g. a compression step having greater compression towards the edge of the pulp mat). As shown in Figure 3A, the tapered edge region 144 of the pulp mat 122B is asymmetrically tapered, forming a bevelled edge region, having a bevelled surface 144S provided along the edge on one side 122C of the pulp mat, whilst the other side 122D of the pulp mat remains flat.

The tapered edge region 144 of the pulp mat 122B may be compressed to form the bevelled surface 144S by a bevelling roller 140 with a bevelled rolling surface 142. During rolling, the bevelled roller 140 pushes material of the pulp mat 122B away from the edge of the pulp mat, reducing the risk of compromising the adjacent seal 126 to be formed (e.g. by adhesive or by stitching) in a margin M around the pulp mat 122B of the thermally insulating member 120B.

Alternatively, one or more edge regions of each pulp mat 122B may be compressed to form a tapered edge region 144 of tapered thickness T that reduces towards the edge of the pulp mat 122B, 144after assembly between the sheet layers 124, as shown in Figure 3B. Similarly to Figure 3A, the tapered edge region 144 of the pulp mat 122B may be asymmetrically tapered, with a bevelled surface 144S being provided along the edge on one side 122C of the pulp mat, whilst the other side 122D of the pulp mat remains flat. As shown in Figure 3B, the seal 126 (e.g. adhesive bond or stitching) may be formed between the sheet layers 124 in a margin M around the pulp mat 122B. In the case that the seal 126 is formed by adhesive, the seal 126 and the tapered edge region 144 of the pulp mat 122B may be formed by a single compression step by the bevelling roller 140, reducing the number of manufacturing steps required to form the thermally insulating member 120B.

The tapered edge region 144 of the pulp mat 122B may be tapered at an angle e (theta) of between 30 degrees and 60 degrees, e.g. 45 degrees.

Figure 3C shows a thermally insulating member 120B formed with a pulp mat 122B having an tapered edge region 144 (e.g. having a bevelled surface 144S) with a tapered thickness T, as shown in Figure 3A.

Figure 3D shows part of a pre-formed thermally insulated folding carton 100A adjacent a corner 112, having thermally insulating members 120B in which the tapered edge regions 144 of the pulp mats 122B have an asymmetrically tapered thicknesses (i.e. bevelled), with corresponding bevelled surfaces 144S. The thermally insulating members 120B are closely positioned at the corner 112 between adjacent panels 110S, 110F1, 110F2 of the folding carton 110, so that the pulp mats 122B are adjacent and press together (e.g. separated only by their covering sheet layers 124, and optionally one or both with an intervening margin M of one or both of the thermally insulating members 120B). The tapered edge regions 144 of the pulp mats 122B provide an enhanced fit between adjacent thermally insulating members 120B, compared with perpendicularly edged pulp mats 122, producing a seal against air currents that enhances thermal insulation performance of the thermally insulated folding carton 100A.

Figure 3E shows a corresponding view to Figure 3D, for the partially formed blank assembly 100C in a collapsed state. (To simplify the illustration, the sheet layers 124 and seal 126 have been omitted from Figure 3E.) In the acutely angled corners 112 of the collapsed partially formed blank assembly 100C, the tapered edge regions (bevelled edge regions) 144 of the pulp mats 122B enable the partially formed blank assembly 100C to be collapsed flatter, with more acutely angled R (beta) corners 112, whilst avoiding excessive bowing of the carton 110 adjacent the corner 112, which may reduce the structural integrity of the carton 110 in subsequent use, compared with the use of perpendicularly edged pulp mats 122. The pulp mats 122B are resiliently deformable, so compress, when pressed together in the acute corner of a partially collapsed carton 110. The use of tapered edge regions 144, and particularly the use of bevelled edge regions in which the bevelled surfaces 144S of the adjacent pulp mats 122B face towards each other, enables partially formed blank assemblies 100C to be more compactly and economically transported and stored, than if using perpendicularly edged pulp mats 122.

As illustrated in Figures 1A to 1J, one or more flexible thermally insulating members may be connected as thermally insulating lining to a thermally insulated folding carton 100 in the pre-formed state 100A, as a blank assembly 100B, or as a partially-formed blank assembly 100C.

Additionally, the thermally insulating member 120B having a pulp mat 122B with a compressed tapered edge region 144 (e.g. having a bevelled surface 144S) may be produced separately, for other thermal insulation uses.

The figures provided herein are schematic and not to scale.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to", and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

CLAIMS1. A blank assembly (100B) for a thermally insulated folding carton (100A) comprising: a folding carton blank (110) for forming into a formed carton having carton sides (110S), a carton first end (110E1) for the insertion of contents into the carton, and an opposed carton second end (110E2), the formed carton having interior surfaces and exterior surfaces; and one or more flexible thermally insulating members (120, 120B) connected to one or more interior surfaces of respective carton sides (110S).
2. The blank assembly of claim 1, comprising a plurality of the thermally insulating members (120, 120B) connected to interior surfaces of respective carton sides (110S).
3. The blank assembly of claim 1, wherein a thermally insulating member (120, 120B) is bonded to the interior surface of each carton side (110S). 15
4. The blank assembly of any preceding claim, wherein the one or more thermally insulating members (120, 120B) are configured to provide, in use, at least one layer of thermally insulating member (120, 120B) between a product within the carton (110) and the interior surfaces of the carton first end (110E1) and the carton second end (110E2).
5. The blank assembly of any preceding claim, wherein each of the one or more thermally insulating members (120, 120B) is connected to the interior surface of the carton sides (110S) in a second region (H2) adjacent the carton second end (110E2), and is not connected to the interior surface of the carton sides in a first region (H1) adjacent the carton first end (110E1).
6. The blank assembly of claim 5, wherein the carton (110) has a height (HO) extending between the carton first end (110E1) and the carton second end (110E2), and the first region (H1) extends up the carton side by at least 25% of the height (HO).
7. The blank assembly of claim 5, wherein the first region (H1) extends up the carton side by at least 40% of the height (HO).
8. The blank assembly of any preceding claim, wherein the one or more thermally insulating members (120, 120B) each comprise a pulp mat (122, 122B) between first and second sheet layers (124).
9. The blank assembly of claim 8, wherein the pulp mats (122B) of adjacent thermally insulating members have adjacent tapered mat edge regions (144), and in each adjacent tapered mat edge region (144) the thickness (T) of the pulp mat (122B) has a tapered thickness profile that reduces towards a respective edge of the pulp mat (122B).
10. The blank assembly of claim 9, wherein in the tapered mat edge regions (144), one side (122C) of the pulp mat (122B) is provided with a bevelled surface (144S) and the other side (122D) of the pulp mat (122B) is flat.
11. The blank assembly of claim 8, claim 9 or claim 10, wherein the pulp mat (122, 122B) is a cellulosic pulp mat.
12. The blank assembly of any one of claims 8 to 11, wherein the sheet layers (124) are cellulosic sheet layers.
13. The blank assembly of any one of claims 8 to 12, wherein an adhesive bonds together the first and second sheet layers (124) within a margin (M) around the periphery of the sheet layers (124).
14. The blank assembly of any one of claims 8 to 12, wherein the first and second sheet layers (124) are stitched together with thread within a margin (M) around the periphery of the sheet layers (124).
15. The blank assembly of any preceding claim, wherein the carton blank (110) is formed from cellulosic card stock, corrugated fibreboard, or paperboard.
16. The blank assembly of any preceding claim, wherein the formed carton (110) is a rectangular cuboidal formed carton.
17. A partially formed blank assembly (100C) comprising the blank assembly (100B) of any preceding claim, wherein carton sides (110S) of the folding carton blank (100B) have opposed edges that are connected together to form a tubular assembly of carton sides (110S).
18. A thermally insulated folding carton comprising the blank assembly (100B, 100C) of any one of claims 1 to 16, or the partially formed blank assembly (100C) of claim 17, wherein the folding carton blank (110B) is formed into a pre-formed carton.
19. A method of forming a blank assembly (100B) for a thermally insulated folding carton (100A) comprising: forming a folding carton blank (110) for forming into a formed carton having carton sides (110S), a carton first end (110E1) for the insertion of contents into the carton, and an opposed carton second end (110E2), the formed carton having interior surfaces and exterior surfaces; and connecting one or more flexible thermally insulating members (120, 120B) to one or more interior surfaces of respective carton sides (110S).
20. A method of forming a partially formed blank assembly (100C) comprising connecting together opposed edges of carton sides (110S) of the folding carton blank (100B) of claim 19 to form a tubular assembly of carton sides (110S).
21. The method of claim 19 or claim 20, wherein the one or more thermally insulating members (120, 120B) each comprise a pulp mat (122B) between first and second sheet layers (124), wherein the pulp mats (122B) of adjacent thermally insulating members have adjacent tapered mat edge regions (144), and in each adjacent tapered mat edge region (144) the thickness (T) of the pulp mat (122B) has a tapered thickness profile that reduces towards a respective edge of the pulp mat (122B), the method comprising compressing an edge region of a pulp mat (122B) to form the tapered mat edge region (144) having the tapered thickness profile.
22. The method of claim 21, wherein in the tapered mat edge regions (144), one side (122C) of the pulp mat (122B) is provided with a bevelled surface (144S) and the other side (122D) of the pulp mat (122B) is flat.
23. The method of claim 21 or claim 22, wherein compressing the tapered edge region (144) of the pulp mat (122B) comprises compressing with a bevelling roller (140).
24. The method of claim 23, wherein compressing with the bevelling roller (140) comprises forming an adhesive bond (126) between the first and second sheet layers (124).
25. A blank assembly (100B) for a thermally insulated folding carton (100A), a partially formed blank assembly (100C) for a thermally insulated folding carton (100A) or a thermally insulated folding carton (100A) formed by the method of any one of claims 19 to 24.
26. A thermally insulating member (120B) comprising a pulp mat (122B) between first and second sheet layers (124), wherein the pulp mat (122B) has one or more tapered mat edge regions (144), and in each adjacent tapered mat edge region (144) the thickness (T) of the pulp mat (122B) has a tapered thickness profile that reduces towards a respective edge of the pulp mat (122B).
27. The thermally insulating member (120B) of claim 25, wherein in the tapered mat edge regions (144), one side (122C) of the pulp mat (122B) is provided with a bevelled surface (144S) and the other side (122D) of the pulp mat (122B) is flat.
28. The thermally insulating member (120B) of claim 25 or claim 26, wherein the pulp mat (122, 122B) is a cellulosic pulp mat.
29. The thermally insulating member (120B) of any one of claims 25 to 27, wherein the sheet layers (124) are cellulosic sheet layers.
30. The thermally insulating member (120B) of any one of claims 25 to 28, wherein an adhesive bonds together the first and second sheet layers (124) within a margin (M) around the periphery of the sheet layers (124).
31. The thermally insulating member (120B) of any one of claims 25 to 28, wherein the first and second sheet layers (124) are stitched together with thread within a margin (M) around the periphery of the sheet layers (124).
32. A method of forming a thermally insulating member (120B) comprising a pulp mat (122B) between first and second sheet layers (124), wherein the pulp mat (122B) has one or more tapered mat edge regions (144), and in each adjacent tapered mat edge region (144) the thickness (T) of the pulp mat (122B) has a tapered thickness profile that reduces towards a respective edge of the pulp mat (122B), the method comprising compressing an edge region of a pulp mat (122B) to form the tapered mat edge region (144) having the tapered thickness profile.
33. The method of claim 31, wherein in the tapered mat edge regions (144), one side (122C) of the pulp mat (122B) is provided with a bevelled surface (144S) and the other side (122D) of the pulp mat (122B) is flat.
34. The method of claim 31 or claim 32, wherein compressing the tapered edge region (144) of the pulp mat (122B) comprises compressing with a bevelling roller (140).
35. The method of claim 33, wherein compressing with the bevelling roller (140) comprises forming an adhesive bond (126) between the first and second sheet layers (124).
36. A thermally insulating member (120B) formed by the method of any one of claims 32 to 35.