GB2622789A

GB2622789A - System for and method of forming receptacle

Info

Publication number: GB2622789A
Application number: GB2214080.0A
Authority: GB
Inventors: George Prozesky Daniel
Original assignee: Pulpex Ltd
Current assignee: Pulpex Ltd
Priority date: 2022-09-27
Filing date: 2022-09-27
Publication date: 2024-04-03
Also published as: GB202214080D0; WO2024069163A1

Abstract

A system comprises a mould 15, a first cavity 36 and a first opening 46 into the first cavity, the first opening has a first width, an expandable member 19, such as a bladder, insertable and expandable into the first cavity, a support 100, a second cavity 42 and a second opening 46 into the second cavity, the second opening has a second width that is different to the first width, the support supports the expandable member within the second cavity, such that the expandable member extends out of the second opening and abuts the receptacle mould when the expandable member is expanded. The second width maybe greater than the first width, a wall thickness of a portion of the expandable member maybe thicker than a wall thickness of another portion. The first and second openings may comprise a fillet or chamfer edge. Fluid maybe supplied into the expandable member. A method of forming a receptacle in a mould is provided, introducing a fibre suspension or a partially formed receptacle into the first cavity of the mould. Pulp-moulded bottles can reduce the amount of plastic used in disposable consumer goods. The solution reduces or avoids pinching of the expandable member.

Description

SYSTEM FOR AND METHOD OF FORMING A RECEPTACLE TECHNICAL FIELD

The present invention relates to a system for moulding a receptacle and a method of forming a receptacle in a receptacle mould. The receptacle mould is useable to mould the receptacle from a fibre suspension, such as a fibre suspension comprising paper pulp The receptacles may form consumer packaging, such as bottles, useful for holding liquids, powders, other flowable materials or solid objects.

BACKGROUND

Bottles made from a fibre suspension are known and may be used in place of plastic bottles. These -pulp-moulded" bottles can therefore reduce the amount of plastic used in disposable consumer goods Published patent document W02018/020219A1 describes forming a bottle from paper pulp in a mould. A fibre suspension is introduced into a mould and a layer is deposited on the inside of the mould. From here, a deflated "bladder" is introduced into the mould and is expanded. The expansion of the bladder presses the fibre suspension against the mould to force at least some water out of the fibre suspension, resulting in a bottle being formed. This process of removing water is commonly known as "dewatering-.

SUMMARY

As mentioned, the use of an expandable bladder (referred to herein as an expandable member or inflatable member) in forming pulp-moulded receptacles is known. The expandable member may be attached to a "support" while the expandable member is inserted into, and expanded within, a mould The support may have an inner cavity inside of which the expandable member is coupled/attached to the support. The expandable member can extend out of this cavity through an opening in the support, while it is being expanded. To insert the expandable member into the mould, the support may move towards the mould, so that the expandable member can extend into the mould through an opening in the mould. The support may generally be in abutment with the mould (such as the top of the mould) during moulding.

However, a problem with such a system is that as the expandable member is expanded, the support can separate (i.e., move away) from contact with the mould, due to the force that the expandable member applies to the inside of the mould. This can cause a gap to exist between the mould and the support, and the expandable member can expand into this gap. When the expandable member is deflated at a later point in time, the expandable member can become trapped or "pinched" between the mould and the support as the support and mould move back together, and the gap is closed. This can pierce, damage or otherwise weaken the expandable member.

To mitigate this problem, the inventors have designed a support where the opening into the cavity of the support has a different "width" or "diameter" to the opening into a cavity of the mould. Haying these two openings a different size to each other ensures that when the expandable member is expanded it is less likely to expand into the gap that forms between the support and the mould.

In a first example, the opening into the support is wider than the opening into the mould. This provides wider space inside the support and allows the expandable member to expand inside the support (i.e., above the mould). The expandable member therefore expands into this space, instead of into the gap between the support and the mould. In a second example, however, the opening into the support is narrower than the opening into the mould. This provides a wider space inside the mould. Although both solutions reduce or avoid the "pinching" of the expandable member, the first example may be preferred in some cases because this ensures that the expandable member is expanding inside the support, thereby avoiding damaging or "interrupting" the receptacle that is being moulded.

As such, according to a first aspect of the present invention, there is provided a system for moulding a receptacle, the system comprising: (i) a receptacle mould comprising a first cavity and a first opening into the first cavity, the first opening having a first width, (ii) an expandable member configured to be insertable into the first cavity of the receptacle mould via the first opening and thereafter expandable within the first cavity, and (iii) a support comprising a second cavity and a second opening into the second cavity, the second opening having a second width that is different to the first width. The support is configured to: (a) support the expandable member within the second cavity, such that the expandable member extends out of the second opening, and (b) abut the receptacle mould when the expandable member is expanded, such that the expandable member is expanded within the first cavity and the second cavity.

The expandable member may extend out of the second opening while being expanded within the first cavity, in some examples. The expandable member may be retracted into the second cavity at other times.

As mentioned, in some examples, the second width is greater than the first width.

Having the second opening wider than the first opening by at least this amount has been found to reduce the likelihood of the expandable member from expanding into the gap.

In other examples, the first width is greater than the second width The widths of the openings may be known as diameters or cross-sectional widths/diameters, in some examples.

The first cavity may be known as a cavity or inner cavity or void or space within the mould. Similarly, the second cavity may be known as a cavity or inner cavity or void or space within the support. The expandable member may be known as a bladder, expandable element, expandable member or expandable element, in some examples. The support may be known as a "bung", support element, support assembly or support member in other examples. The first opening may be known as an aperture or mould aperture. Similarly, the second opening may be known as an aperture or support aperture.

As mentioned, the support holds/supports the expandable member within the second cavity, such that the expandable member extends out of the second opening. The support may therefore be coupled to the expandable member. In one example, the support comprises a holder and the expandable member is coupled to the holder within the second cavity. For example, the expandable member may be stretched around the holder. A connector may secure the expandable member to the holder. In an example, the holder is a tube or a rod or a rod-like element that can extend inside the expandable member. The rod may also extend into the first cavity when the support abuts the mould. The rod can provide rigidity to the expandable member and help keep the expandable member centred within the mould to avoid damaging the receptacle.

As mentioned, the support can abut/contact the receptacle mould when the expandable member is expanded (at least initially, before being urged away from the mould due to the expansion of the expandable member). The support may move, or be moved, towards the mould so that the expandable member can be inserted into the first cavity (i e., the cavity of the mould). Alternatively, the mould may move, or be moved, towards the support. Thus, the relative movement between the mould and the expandable member (and/or support) causes the expandable member to be guided into the first cavity. A mechanical arm may move the support (or mould).

In certain examples, the receptacle may be known as a moulded receptacle, an article, a bottle, a container, a receptacle for containing fluid (such as a liquid) or solids (such as pharmaceutical or other tablets/capsules), an article for containing fluid, a bottle for containing fluid, a container for containing fluid, etc. The receptacle may be moulded from a fibre suspension, including constituents such as paper pulp. A fibre suspension may contain, amongst other things, cellulose fibres and a liquid, such as water. Additives may be present in the fibre suspension.

The receptacle may have a longitudinal axis along its length. The length/height of the receptacle may be greater than a width and/or depth of the receptacle. In some examples, the receptacle may have a generally circular footprint owing to a generally cylindrical form of the receptacle (at least along a portion of its length). In some examples, the receptacle may have a footprint that is square, rounded square, squircular, or superelliptical.

As mentioned, the receptacle mould (also referred to as a mould) defines a first cavity (also known as a "cavity" or "mould cavity") therein, and a layer or coating of the fibre suspension can be applied to the inner wall of the first cavity (the "mould cavity wall") This initial layer/coating may have a first thickness, and after the expandable member has been expanded, the receptacle/fibre suspension may have a second thickness that is less than the first thickness, owing to the compaction of the fibres and removal of some of the liquid.

In some examples, the first cavity has a main body portion (also known as a first portion) and a neck portion (also known as a second portion). Both portions of the first cavity together form the first cavity. The neck portion may be used to form the neck of the receptacle. A closure such as a lid/cap may be applied to an end of the neck of the receptacle, for example. In some examples, the main body portion has a cross-sectional width that is larger than the cross-sectional width of the neck portion (the cross-section being taken in a plane parallel to a longitudinal axis of the receptacle mould).

In some examples, the mould is part of a split-mould, the split-mould being made of two or more moulds. For example, the mould may form half (or a third, or a quarter, etc.) of a split-mould and be brought together with at least one other mould before receiving the fibre suspension therein. The first cavity may therefore only form a portion of the overall cavity of the split-mould and the first cavity may therefore be used to form only part of an outer surface of the moulded receptacle. In some examples, the moulds forming the split-mould may be identical, but in other examples they may differ.

In some examples, the first cavity has apertures formed on/through the mould cavity wall. This allows liquid to pass from within the first cavity to the outside of the mould. The apertures may therefore extend from the first cavity to an outer surface of the mould.

In an example, at least part of the mould is formed via a 3D printing or other additive manufacturing technique. In an example, the mould is metal (e.g. the mould is metallic). For example, the mould comprises stainless steel, or aluminium.

In a particular example, the receptacle has a width (such as a diameter) of between about 65mm and 70mm, a height of between about 190mm and about 200mm, and a volume of between about 500m1 and 600m1. In a further example, the receptacle has a diameter of about 68mm, a height of about 196mm and a volume of about 550m1.

In some examples, to further protect the expandable member from being damaged or from expanding into the gap and becoming trapped, the expandable member may be made of a thicker material in the vicinity of the support/mould contact area. This has two advantages: (i) the thicker material is more resistant to damage if the expandable member does become trapped between the mould and the support, and (ii) the expandable member is less likely to "stretch" as far as the contact region between the support and mould (i.e., into the gap). The thicker material therefore reduces the capacity of the portion of the expandable member to expand at a given pressure. For example, the thicker material increases the stiffness of the portion of the expandable member. Accordingly, in certain examples, a wall thickness of a portion of the expandable member disposed at least partially within the second cavity is thicker than a wall thickness of a portion of the expandable member disposed within the first cavity, when the support abuts the receptacle mould. Thus, the wall thickness of the expandable member located in the support is greater/thicker than the wall thickness of the expandable member inside the mould. In an example, the portion of the expandable member disposed at least partially within the second cavity has a lower stiffness than the portion of the expandable member disposed within the first cavity.

In some examples, the first opening comprises a fillet or chamfer edge. The first opening therefore has a "smooth" or curved edge that reduces the likelihood of damaging the expandable member when it is inserted into or removed from the first cavity and/or when it is being expanded. Similarly, in certain examples, the second opening comprises a fillet or chamfer edge. The second opening therefore has a "smooth' or curved edge that reduces the likelihood of damaging the expandable member when it is being expanded.

To ensure that the expandable member is centrally located within the second cavity when it is expanded (and therefore equidistant from any gap formed between the support and the mould), the first opening and the second opening may be centred on the same point, or aligned. As a further advantage, this also ensures that the expandable member is centrally located within the first cavity when inserted into the mould and is therefore positioned away from any receptacle being formed on the inner wall of the first cavity. Accordingly, in some examples, the second opening has an axis that is coaxial with an axis of the first cavity. Put another way: (i) the axis of the first cavity is coaxial with an axis of the second cavity, or (ii) the expandable member defines an axis, and the axis of the expandable member is coaxial with the axis of the first cavity and the axis of the second cavity, or (ii) a midpoint of the first opening is collocated/aligned with a midpoint of the second opening.

In some examples, the first opening and the second opening are the same shape (and a different size). Having the same shaped opening means that the expandable member is not compressed unevenly as it expands. Furthermore, when the second opening is wider than the first opening, the support can evenly surround the opening of the mould. When expanded, the expandable member may also have a cross-sectional shape that is the same as the shape of the first and second openings. This can more evenly distribute any forces applied to the expandable member.

In a particular example, the first opening and the second opening are circular. A circular opening has no sharp corners that could damage the expandable member as it is being expanded. Furthermore, the circular openings create an annular void into which the expandable member can expand In a particular example, the system further comprises a fluid supply system configured to supply a fluid into the expandable member to maintain a pressure of between about 15 bar and about 25 bar within the expandable member, such as about bar. This pressure allows the expandable member to remove liquid from the receptacle/fibre suspension inside the first cavity of the mould In examples, the support is made of a rigid material; the support is substantially rigid. For example, the support comprises rigid material. In an example, the support is made of metal, such as stainless steel, or aluminium. For example, the support comprises metal such as stainless steel, or aluminium. In examples, the support is metal (e.g. the support is metallic). Advantageously, a support made of metal can withstand high mechanical load and/or high temperatures which may be experienced during expansion of the expandable member without substantial deformation. In another example, the support is made from a polymeric material, such as plastics, particularly a rigid polymeric material. For example, the support comprises a polymer resin, such as polyoxymethylene (POM). In particular examples, the support is made of Delrin0 acetal homopolymer, available from the vendor DuPont. Advantageously, a support comprising such a polymeric material such as polyoxymethylene (POM) may exhibit high-wear resistance, high strength and stiffness, and be suitable for use across a wide temperature range. In other examples, the support is made from rubber or any other deformable material, such as silicon. For example, the support comprises deformable material (e.g. the support is at least partly deformable). A deformable material may avoid damaging the expandable member if it does become trapped between the support and the mould.

In some examples, the support is made of a rigid material (e.g, metal or rigid polymeric material) and a deformable material; a first portion of the support is made of rigid material, and a second portion of the support is made of a deformable material, such as silicon. In some examples, the support is arranged to have a rigid first portion and a deformable second portion such that, in use, the second portion of the support faces, or abuts, the receptacle mould. Advantageously, this arrangement allows for the support to contact the receptacle mould throughout expansion and deflation of the expandable member due to compression and expansion of the deformable second portion, thereby reducing the risk of a portion of the expandable member becoming trapped or "pinched' between the mould and the support upon expansion of the expandable member. In other examples, the support is arranged such that, in use, a rigid portion (e.g. a metal portion or a rigid polymeric portion) of the support faces, or abuts, the receptacle mould. Advantageously, this arrangement may result in the support having a longer usable lifespan, as the rigid portion may be less prone to degradation than a deformable material.

According to a second aspect of the present invention, there is provided a method of forming a receptacle in a receptacle mould, the receptacle mould comprising a first cavity and a first opening into the first cavity, the first opening having a first width, the method comprising: (i) introducing a component into the first cavity of the receptacle mould, the component being a fibre suspension or a partially formed receptacle and (ii) moving a support towards the receptacle mould until the support abuts the receptacle mould. The support: (a) comprises a second cavity and a second opening into the second cavity, the second opening having a second width that is different to the first width, and (b) supports an expandable member within the second cavity, such that the expandable member extends out of the second opening. The method further comprises: (iii) introducing the expandable member into the first cavity via the first opening, and (iv) expanding the expandable member, such that the expandable member expands within the first cavity to urge the component against an inner surface of the first cavity, thereby to help form the receptacle, and expands within the second cavity.

In certain examples, the expandable member is an inflatable member, and expanding the expandable member comprises inflating the inflatable member.

In some examples, the method further comprises deflating the expandable member in the first cavity. In some examples, the method further comprises moving the support away from the receptacle mould to remove the expandable member from the first cavity.

In some examples, expanding the expandable member causes the support to move away from the mould (so that they no longer abut), at least temporarily. The support and mould may abut again after the expandable member has deflated.

In some examples, moving the support towards the receptacle mould causes the expandable member to be introduced into the first cavity via the first opening. In other examples, the actions may be distinct. For example, after the support abuts the mould, the expandable member may then be inserted into the first cavity.

Introducing a component into the first cavity of the receptacle mould may comprise spraying/inserting/drawing the fibre suspension into the first mould. In some instances, the fibre suspension may be introduced under vacuum (i.e., a vacuum is applied to the mould or first cavity). In certain examples, fibre suspension used to form the receptacle is introduced into the first cavity via the first opening Introducing a component into the first cavity of the receptacle mould may comprise inserting or placing a partially formed receptacle into the first mould. The partially formed receptacle may be "unfinished" and have been formed in another mould using the same or a different expandable member. The expandable member is used to urge the partially formed receptacle against the inner wall of the first cavity as part of a drying (such as thermoforming) step. The mould may be heated, in some examples.

In some examples, expanding the expandable member comprises: (i) expanding the expandable member within the second cavity, and maintaining a distance between an inner wall of the support and an outer surface of the expandable member, at the second opening. This ensures that there is a distance between the inner wall of the support at the opening and the expandable member, to reduce the likelihood of pinching the expandable member between the support and the mould. The inner wall of the support may be the inner wall of the second cavity.

In examples where the second opening is wider than the first opening, expanding the expandable member causes the expandable member to have a cross-sectional width within the second cavity that is wider than the first opening That is, the expandable member expands into the wider second cavity.

In a third aspect of the present invention there is provided a support for supporting an expandable member when the supporting element is disposed within a receptacle mould, the support comprising: (i) a contact surface configured to abut the receptacle mould, (ii) a cavity in which the expandable member can be at least partially disposed, (i0) an opening to the cavity through which the expandable member can extend, and (iv) a holder configured to support the expandable member at least partially within the cavity, wherein the opening to the cavity is configured to have a width that is different (such as greater) than a width of an opening of the receptacle mould. The opening into the cavity may be the second opening into the second cavity. The opening into the mould may be the first opening into the first cavity.

In some examples, the holder is hollow such that a fluid can flow through the holding element into the expandable member.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an example of a process for producing a receptacle at least partially moulded from a fibre suspension; Figure 2A shows a cross-section of an example mould and an example support being moved towards the mould, Figure 2B shows the mould and support of Figure 2A after they have been brought into contact; Figure 2C shows the mould and support of Figure 2B as a fluid is being introduced into an example expandable member, Figure 2D shows the mould and support of Figure 2C when the expandable member has been fully expanded, Figure 3A shows a cross-section of an example mould and a second example support being moved towards the mould; Figure 3B shows the mould and support of Figure 3A after they have been brought into contact; Figure 3C shows the mould and support of Figure 3B as a fluid is being introduced into an example expandable member; Figure 3D shows the mould and support of Figure 3C when the expandable member has been fully expanded; Figure 4 shows a cross-section of an example mould and a third example support in abutment with the mould; and Figure 5 shows an example flow diagram of a method of forming a receptacle in a receptacle mould.

DETAILED DESCRIPTION

The following description presents exemplary embodiments and, together with the drawings, serves to explain principles of embodiments of the invention.

Figure I shows a process for making bottles from paper pulp (i.e., which can form the basis of an example fibre suspension). The process is merely exemplary and is provided to give context to examples of the present invention. Broadly speaking, the exemplary process comprises providing a fibre suspension, introducing the fibre suspension into a mould cavity of a porous first mould and using the porous first mould to expel a liquid (such as water) from the fibre suspension to produce a wet precursor or embryo (which may itself be considered a moulded receptacle), further moulding the wet precursor in a mould to produce a further-moulded receptacle, coating the further-moulded receptacle to produce a coated moulded receptacle, drying the coated moulded receptacle to produce a dried receptacle, and applying a closure to the dried receptacle As will be apparent at least from the following description, modifications may be made to the exemplary process to provide variants thereof in which other examples of the present invention may be embodied.

In this example, providing the fibre suspension comprises preparing the fibre suspension from ingredients thereof More specifically, the preparing comprises providing pulp fibres, such as paper pulp fibres, and mixing the pulp fibres with a liquid to provide hydrated pulp fibres. In this example, the pulp fibres are provided in sheet form from a supplier and the liquid comprises water and one or more additives. In this example, the liquid is mixed with the pulp fibres to provide hydrated pulp fibres having a solid fibres content of lwt% to 5wt% (by dry mass of fibres). In examples, the one or more additives includes a sizing agent, such as alkylketene dimer (AKD). The hydrated pulp fibres typically comprise AKD in an amount of 0.4wt% with respect to the total dry mass of the solid fibres in the hydrated pulp fibres. In some examples, one or more additives are present in the liquid at the point of mixing the pulp fibres with the liquid In some examples, one or more additives are included in the hydrated pulp fibres after mixing the pulp fibres with the liquid (e.g. the pulp fibres are hydrated for a period of time, such as from 2 to 16 hours, and then one or more additives are supplied to the hydrated pulp fibres). The hydrated pulp fibres are passed between plates of a valley beater 11 or refiner that are in motion relative to each other. This fibrillates some, or all, of the fibres, meaning that cell walls of those fibres are caused to become partially delaminated so that wetted surfaces of those fibres comprise protruding hairs or fibrillations. These fibrillations will help to increase a strength of bonds between the fibres in the dried end product. In other examples, the valley beater 11 or refiner may be omitted.

The resultant processed pulp is stored in a vat 12 in a relatively concentrated form (e.g. a solid fibres content of lwt% to 5wt%) to reduce a required storage space. At an appropriate time, the processed pulp is transferred to a mixing station 13 at which the processed pulp is diluted in further water and, optionally, mixed with one or more additives (as well as, or in place of, the one or more additives provided with the hydrated pulp fibres) to provide the fibre suspension ready for moulding. In this example, the solid fibres account for 0.7wt% of the resultant fibre suspension (by dry weight of fibres), but in other examples the proportion of solid fibres in the fibre suspension may be different, such as another value in the range of 0.5w04, to 5wt%, or 0. lwt% to lwt%, of the fibre suspension (by dry weight of fibres). In some examples, the one or more additives mixed with the processed pulp and water includes a dewatering agent. In some examples, the one or more additives are mixed with the water, and the water and one or more additives subsequently mixed with the processed pulp; in other examples, the processed pulp and water are mixed, and the one or more additives subsequently mixed with the processed pulp and water. The fibre suspension typically comprises dewatering agent in an amount of 0.3wt% with respect to the total dry mass of the solid fibres. Mixing of the fibre suspension at the mixing station 13 helps to homogenise the fibre suspension. In other examples, the processed pulp or the fibre suspension may be provided in other ways, such as being supplied ready-made.

In this example, the porous first mould 15 comprises two half-moulds that are movable towards and away from each other, in this case using a hydraulic ram. In this example, each of the half-moulds is a monolithic or unitary tool formed by additive manufacturing (e.g. 3D-printing) that defines a mould profile, and, when the half-moulds are brought into contact with each other, their respective mould profiles cooperate to define the mould cavity in which the wet precursor or moulded receptacle is to be formed. Each half-mould may itself define a smaller moulding cavity and, when brought into cooperation with a second half-mould, the smaller moulding cavities may combine to provide the overall mould cavity. The two half-moulds may themselves be considered "splits" or "moulds" and the overall porous first mould 15 may be considered a "split-mould" or, again, a -mould". In other examples, the porous first mould 15 may comprise more than two splits, such as three, four or six splits, that cooperate to define the moulding cavity.

In Figure 1, the fibre suspension (also known as slurry) is top-filled into the porous mould 15, in contrast to moulding processes that dip a mould in slurry. The fibre suspension is drawn under vacuum via a line 16 and into the porous mould 15, with excess suspending liquid being drawn through the porous mould 15 under vacuum via a line 18 into a tank 17. Shot mass may be controlled by measuring (e.g., weighing) the amount of liquid drawn into the tank 17. A weight scale platform supporting the tank 17 is visible in Figure 1. Once a required amount (e.g. a predetermined volume, such as 10 litres, or a predetermined mass, such as 10 kilograms) of liquid has been collected in the tank 17, suction of the suspending liquid through the porous mould 15 is stopped and the porous mould 15 is opened to ambient air. In this example, the suspending liquid drawn with the fibre suspension in line 16 is water, or predominantly water (as additives may also be present). The liquid drawn under vacuum via the line 18 and into the tank 17 is substantially free of fibres, since these are left behind against the walls of the porous mould 15 to form an embryo of the moulded receptacle.

In one form, in order to remove further suspending liquid (e.g., water) from the embryo, and form or consolidate the three-dimensional shape of the receptacle, an impermeable inflation element 19, e.g., a collapsible bladder (also known as an expandable or inflatable member/element), is inserted into the porous mould 15 and expanded to act as an internal high-pressure core structure for the porous mould 15. This process strengthens the wet embryo so that it can be handled, and displaces water from in between the fibres, thereby increasing the efficiency of a subsequent drying process.

The inflation element 19 is actuated and regulated using a hydraulic pump 20. The pump 20 has a cylinder that displaces a fluid in a line 21 into the inflation element 19, to expand the inflation element 19 radially and into conformity with the mould cavity. Fluid within the line 21 is preferably non-compressible, such as water. Water also has the advantage over other non-compressible liquids that any leaking or bursting of the bladder 19 will not introduce a new substance to the system (since the suspending liquid is already water, or predominantly water).

Demoulding occurs when the porous mould 15 opens for removal of the self-supporting moulded receptacle 22. Mould cleaning 23 is preferably performed subsequently, to remove small fibres and maintain a porosity of the porous mould 15. In this example, a radially firing high-pressure jet is inserted into the mould cavity while the mould 15 is open. This dislodges fibres from the wall of the mould cavity. Alternatively, or in addition, water from the tank 17 is pressurised through the back of the porous mould 15 to dislodge entrapped fibres. Water is drained for recycling back to an upstream part of the system. It is noteworthy that cleaning is important for conditioning the porous mould 15 for re-use. The porous mould b may appear visibly clean after removal of the receptacle, but its performance could be compromised without cleaning.

According to Figure 1, the formed but unfinished receptacle 22 is subsequently transported to a second moulding station where, in a, e.g., aluminium, mould 25, pressure and heat are applied for thermoforming a desired neck and surface finish, optionally including embossed and/or debossed surface features. After two halves of the mould 25 have closed around the receptacle 22, a pressuriser is engaged. For example, a bladder 26 (e.g., a thermoforming bladder 26) is inserted into the receptacle 22. The bladder 26 is expanded via a line 27 by a pump 28 to supply pressurised fluid, e.g., air, water, or oil.

Optionally, during supply, the pressurised fluid is heated with e.g. a heater or, alternatively, is cooled with e.g. a heat exchanger. An external mould block 24 of the mould 25, and/or the mould 25 itself, may also, or alternatively, be heated. A state of the moulded receptacle 22 after thermoforming is considerably more rigid, with more compressed side walls, compared with the state at demoulding from the porous mould 15.

A drying stage 29 (e.g., a microwave drying process or other drying process) is performed downstream of the thermoforming, as shown. In one example, the drying stage 29 is performed before thermoforming. However, moulding in the mould 25 requires some water content to assist with bonding during the compression process. Figure 1 illustrates a further drying stage 30 after the drying stage 29, which may utilise hot air circulated onto the moulded receptacle 22, e.g., in a "hot box". In some examples, microwave or other drying processes may be performed at plural stages of the overall manufacturing process.

The moulded receptacle 22 is then subjected to a coating stage during which, in this example, a spray lance 31 is inserted into the moulded receptacle 22 and applies one or more surface coatings to internal walls of the moulded receptacle 22. In another example, the moulded receptacle 22 is instead filled with a liquid that coats the internal walls of the moulded receptacle 22. In practice, such coatings provide a protective layer to prevent egress of contents into the bottle wall, which may permeate and/or weaken it.

Coatings will be selected dependent on the intended contents of receptacle 22, e.g., a beverage, detergent, pharmaceutical product, etc. In some examples, the further drying stage 30 is performed after the coating stage (or both before and after the coating stage). In this example, the moulded receptacle 22 is then subjected to a curing process 34, which can be configured or optimised dependent on the coating, e.g., drying for twenty-four hours at ambient conditions or by a flash drying method. In some examples, e.g., where the further drying stage 30 occurs after the coating stage, the curing process 34 may be omitted.

At an appropriate stage of production (e.g., during thermoforming, or before or after coating) a closure or mouth forming process may be performed on the moulded receptacle 22. For example, as shown in Figure 1, a neck fitment 35 may be affixed. In some examples, an exterior coating is applied to the moulded receptacle 22, as shown in the further coating stage 32. In one example, the moulded receptacle 22 is dipped into a liquid that coats its outer surface, as shown in Figure 1. One or more further drying or curing processes may then be performed. For example, the moulded receptacle 22 may be allowed to dry in warm air. The moulded receptacle 22 may therefore be frilly formed and ready to accept contents therein.

Figures 2A-2D illustrate the use of an expandable member 19 within a mould 15, where the expandable member 19 and mould 15 correspond to those depicted in Figure 1. As shown, a support 10 is used, and the support 10 has a form that can pinch or trap the expandable member 19 between the support 10 and the mould 15. In contrast, Figures 3A-3D illustrate use an expandable member 19 within a mould 15, where a support 100 according to the present invention is used. In the example of Figures 3A-3D, the support has a form that is specifically designed to reduce the likelihood of pinching or trapping the expandable member 19 between the support 100 and the mould 15. Figure 4 illustrates use of an alternative support 150 according to the present invention. Again, the support 150 is specifically designed to reduce the likelihood of pinching or trapping the expandable member 19 between the support 150 and the mould 15.

As will be explained, in Figures 2A-2D, the support 10 has an opening that is the same size as the opening into the mould 15, whereas, in Figures 3A-3D, the support 100 has an opening wider than the opening of the mould 15, and in Figure 4, the support 150 has an opening narrower than the opening of the mould 15.

The features of Figures 2A-2D, 3A-3D and 6 are shown in cross-section to aid understanding.

Although Figures 2A-2D, 3A-3D and 6 depict a mould 15 and expandable member 19, it will be appreciated that the same principles can be applied to the mould 25 and expandable member 26 depicted in Figure 1. The mould 15 may be porous in some examples.

In more detail, Figure 2A illustrates an example mould 15, and inside the mould is a component 8 (which in this example is a layer of fibre suspension 8). In other examples, the component is a partially formed receptacle, such as that shown in the mould 25 of Figure 1.

The mould 15 comprises a first cavity 36 in which the fibre suspension 8 is located. The first cavity 36 of the mould 15 comprises a mould cavity wall 40 (i.e., the first cavity 36 has an inner wall), and the fibre suspension 8 is applied to the cavity wall 40. In some examples, the first cavity 36 comprises apertures (not shown) that allow liquid to pass therethrough The apertures may extend from the mould cavity wall 40 and through the mould 15 to an outer surface of the mould. In other examples the first cavity 36 is non-porous.

In the example of Figure 2A, the first cavity 36 has a main body portion 36a (also known as a first portion) and a neck portion 36b (also known as a second portion). The neck portion 36b may be used to form the neck of the receptacle/bottle In this example, the mould 15 is formed from two separate half-moulds or 6a, 6b. Each half-mould may itself be referred to as a mould in certain examples, and each half-mould may define a cavity having a mould cavity wall (onto which the fibre suspension 8 may be applied). When the two half-moulds are brought together, the two cavities form the larger first cavity 36 in the mould 15. In other examples, the mould 15 may be made of a single piece.

The mould 15 also has a first opening 38 into the mould 15/first cavity 36. The first opening 38 opens into the first cavity 36 from an outer surface 15a (such as a top surface) of the mould 15. The first opening 38 is therefore formed at the outer surface 15a of the mould 15. The fibre suspension 8 can be introduced into the first cavity 36 via the first opening 38 The expandable member 19 can also be introduced into the mould 15 (or more specifically the first cavity 36) via the first opening 38. Figure 2A shows the expandable member 19 in a deflated state, but extending into the first cavity 36.

At one end 19a of the expandable member 19, the expandable member 19 is connected to, and therefore supported by, the support 10. In this particular example, the expandable member 19 is coupled to a holder 41. The holder 41 comprises a mandrel or rod in some examples (not shown) that extends into the expandable member 19 and into the first cavity 36 to help provide rigidity to the expandable member 19 while it is being inserted into the first cavity 36. A fluid, such as air, water or oil, can flow into the expandable member 19 via the holder 41 to inflate/expand the expandable member 19 within the first cavity 36. Connected to the holder 41 is the line 21 through which the fluid flows from the hydraulic pump 20 shown in Figure 1.

The support 10 defines a second cavity 42 and comprises a second opening 44 that opens into the second cavity 42. The support 10 therefore supports the expandable member 19 within the second cavity 42, and the expandable member 19 extends out of the second opening 44. The second opening 44 opens into the second cavity 42 from an outer surface 10a (such as a bottom surface) of the support 10. The second opening 44 is therefore formed at the outer surface 10a of the support 10.

Figure 2A shows the support 10 being moved towards the mould 15 (in the direction of the two arrows, and thus shows the expandable member 19 at a moment in time where it is partially inserted into the first cavity 36. The support 10 continues to move until it abuts the outer surface 15a of the mould 15.

Figure 2B shows the mould 15 and support 10 at a later point in time when the support 10 and mould 15 are in abutment. The two surfaces 15a, 10a are therefore in contact. In this particular example, the expandable member 19 is inserted fully into the first cavity 36 (i.e., it will extend no further into the first cavity 36). A portion of the expandable member 19 remains in the second cavity 42 As shown most clearly in Figure 2A, the first opening 38 has a first width 46 and the second opening has a second width 48, and the first and second widths 46, 48 are the same size. As shown in Figures 2B and 2C, the inner walls of the second cavity 42 are aligned with the inner walls of the first cavity 36, when the support 10 and mould 15 are in contact Figure 2C shows the mould 15 and support 10 at a further point in time. As shown, a fluid has begun to be supplied to the expandable member 19 and expandable member 19 has started to expand and fill more of the first cavity 36 and the second cavity 42. At this point in time, the support 10 and mould 15 are still in abutment.

Figure 2D shows the mould 15 and support 10 at a further point in time. As shown, the fluid has continued to be supplied to the expandable member 19 and the expandable member 19 now fills substantially the entire first cavity 36. The expandable member 19 has also continued to expand within the second cavity 42. At this point in time, the support and mould 15 are no longer in abutment -instead, the pressure applied by the expandable member 19 to the cavity wall 40 of the first cavity 36 has caused the expandable member 19 to urge the support 10 away from the mould 15, such that a small gap now exists between the two surfaces 15a, 10a. As depicted in Figure 2D, a portion of the expandable member 19 inside the second cavity 42 has expanded into this gap. This means that when the fluid is subsequently drawn out of the expandable member 19 (and the expandable member 19 begins to deflate), the expandable member 19 will be trapped/nipped between the mould 15 and the support 10 as they come into abutment again. This can tear or damage the expandable member 19.

As discussed earlier, the inventors have found that changing the relative sizes/widths of the first and openings 38, 44 (so that they are different) can reduce the likelihood of the expandable member 19 being pinched between the mould and the support Figures 3A-3D therefore depict a first example support 100 according to an embodiment of the invention. This example differs from the example of Figures 2A-2D in that a different support 100 for the expandable member 19 is used. In particular, in this embodiment, the second opening 44 into the second cavity 42 of the support 100 has a width 48 that is greater than the width 46 of first opening 38 into the first cavity 36 of the mould 15. Other than the sizes of the first and second openings 38, 44 and the first and second cavities 36,42, the features of Figures 3A-3D correspond to those described in Figures 2A-2D, so will not be explained again in detail.

Briefly, Figure 3A shows the support 100 being moved towards the mould 15 (in the direction of the two arrows), and thus shows the expandable member 19 at a moment in time where it is partially inserted into the first cavity 36 The support 100 continues to move until it abuts the outer surface 15a of the mould 15.

Figure 3B shows the mould 15 and support 100 at a later point in time when the support 100 and mould 15 are in abutment. The two surfaces 15a, 10a are therefore in contact. In this particular example, the expandable member 19 is inserted fully into the first cavity 36 (i.e., it will extend no further into the first cavity 36). A portion of the expandable member 19 remains in the second cavity 42.

As explained, the first opening 38 has a first width 46 and the second opening has a second width 48, and the second width 48 is greater/wider than the first width 46. As most clearly seen in Figures 3B-3D, the inner walls of the second cavity 42 are set back/positioned away from the inner walls of the first cavity 36 by a distance 50. The second width 48 is therefore greater than the first width by twice this distance 50.

Figure 3C shows the mould 15 and support 100 at a further point in time. As shown, a fluid has begun to be supplied to the expandable member 19, via the line 21 and holder 41, and expandable member 19 has started to expand and fill more of the first cavity 36 and the second cavity 42. At this point in time, the support 100 and mould 15 are still in abutment Figure 3D shows the mould 15 and support 100 at a further point in time. As shown, the fluid has continued to be supplied to the expandable member 19 arid the expandable member 19 is now substantially fully expanded within the first cavity 36. The expandable member 19 has also continued to expand within the second cavity 42, to the extent that the expandable member 19 has a cross-sectional width 64 within the second cavity 42 that is wider than the first opening 38.

At this point in time, the support 100 and mould 15 are no longer in abutment and the pressure applied by the expandable member to the cavity wall 40 of the first cavity 36 has caused the expandable member 19 to urge the support 100 away from the mould 15, such that a small gap now exists between the two surfaces 15a, 100a. As depicted in Figure 3D, a portion of the expandable member 19 inside the second cavity 42 has expanded into the additional space inside the second cavity 42 provided by the larger opening 44. Due to the difference in widths between the first and second openings 38, 44, the expandable member 19 cannot fully extend by the distance 50. The expandable member 19 therefore does not expand into the gap between the mould 15 and support 100, so cannot become trapped between the mould 15 and the support 100 when the expandable member 19 is subsequently deflated.

In certain examples, the material from which the expandable member 19 is made has a non-uniform wall thickness. For example, a portion 52 of the expandable member 19 disposed at least partially within the second cavity 42 may have a wall thickness that is thicker than a wall thickness of a portion of the expandable member 19 disposed within the first cavity 36. This thicker material can limit/reduce the expansion of the expandable member 19 within the second cavity to further reduce the likelihood that the expandable member 19 expands into the gap between the mould 15 and support 100.

In some examples, the first opening 38 comprises a fillet or chamfer edge. In the examples of Figures 3A-3D, the first opening 38 does not have a fillet or chamfered edge, but Figure 3D shows an example dashed outline of a mould 15 having a fillet edge 54. Having such a smooth edge could further reduce the likelihood of damaging the expandable member 19 as it is expanded. In some cases (as in the example of Figures 3A- 3D) the second opening 44 additionally or alternatively comprises a fillet or chamfer edge 56. Thus, the edge 56 is smooth to avoid damaging the expandable member 19 if it does come into contact with the inner wall of the support 100 at the edge 56.

As shown most clearly in Figure 3A, the first and second openings 38, 44 are coaxial (i.e., centred). Figure 3A shows that a first axis 58 (such as a longitudinal axis) of the first opening 38 is coaxial with a second axis 60 (such as a longitudinal axis) of the second opening 44. This ensures that the expandable member 19 is centrally located within the first and second cavities 36, 42 when expanded (and therefore equidistant from the gap formed between the support 100 and the mould 15). The first cavity 36 also defines an axis (such as a longitudinal axis), that is coaxial with the first and second axes 58, 60. Similarly, the second cavity 42 also defines an axis (such as a longitudinal axis), that is coaxial with the first and second axes 58, 60. The axis of the first cavity 36 is therefore also coaxial with the axis of the second cavity 42.

In some examples, the first opening 38 and the second opening 44 are the same shape (i.e., they have the same cross-sectional shape, where the cross section is taken in a plane perpendicular to the axes 58, 60) In this particular example, the first opening 38 and the second opening 44 are both circular in cross-section. Thus, when the support 100 and mould 15 are in abutment, they may be concentrically arranged As mentioned, in Figures 3A-3D, the second width 48 is greater than the first width 46. Figure 4 depicts an alternative support 150, in which the support 150 has a second width 48 that is narrower/smaller than the first width 46. The support 150 therefore also reduces the likelihood of the expandable member 19 becoming trapped between the support 150 and mould 15 because upon inflation, the expandable member 19 cannot expand far enough into any gap formed between the support 150 and mould 15, due to the different sizes of the first and second openings 38, 44 Other than the sizes of the first and second openings 38, 44 and the first and second cavities 36,42, the features of Figure 4 correspond to those described in Figures 2A-2D and 3A-3D, so will not be explained again for brevity.

Figure 5 depicts an example method 200 of forming a receptacle 22 in a receptacle mould 15. As discussed, the mould 15 comprises a first cavity 36 and a first opening 38 into the first cavity 36. The first opening has a first width 46. The method 200 comprises, in block 202, introducing a component 8 into the first cavity 36 of the receptacle mould 15, the component 8 being a fibre suspension or a partially formed receptacle. Figure 3A for example shows the point in time after which the component 8 has been introduced.

The method further comprises, in block 204, moving a support 100, 150 towards the receptacle mould 15 until the support 100, 150 abuts the receptacle mould iS. As mentioned, the support 100, 150 comprises a second cavity 42 and a second opening 44 into the second cavity 42, the second opening 44 having a second width 48 that is different to the first width 46. In the example of Figures 3A-3D, the first width 46 is smaller than the second width 48, and in the example of Figure 4, the second width 46 is smaller than the first width 46. As discussed above, the support 100, 150 supports an expandable member 19 within the second cavity 42, such that the expandable member 19 extends out of the second opening 44.

In block 206, the method further comprises introducing the expandable member 19 into the first cavity 36 via the first opening 38. Figure 3A shows the expandable member 19 being introduced into the first cavity 36 while the support 100 is moving towards the mould 15. In other examples, the expandable member 19 may be introduced into the first cavity 36 once the support 100, 150 has stopped moving and is in abutment with the mould 15. For example, the expandable member 19 may be "unfolded" or "unravelled" once the support 100, 150 and mould 15 are in contact with each other.

In block 208, the method further comprises expanding the expandable member 19 As shown in Figure 3C, the expandable member 19 expands within the first cavity 36 to urge the component 8 against an inner surface 40 of the first cavity 38, thereby to help form the receptacle, and also expands within the second cavity 42.

In some examples, when expanding the expandable member 19 within the second cavity 42, it is useful to maintain a distance 62 (shown in Figure 3D) between an inner wall of the support 100, 150 and an outer surface of the expandable member 19, at the second opening 44. This reduces the likelihood of the expandable member 19 from extending into any gap formed between the support 100, 150 and the mould 15.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

CLAIMS: A system for moulding a receptacle, the system comprising: a receptacle mould comprising a first cavity and a first opening into the first cavity, the first opening having a first width; an expandable member configured to be insertable into the first cavity of the receptacle mould via the first opening and thereafter expandable within the first cavity; and a support comprising a second cavity and a second opening into the second cavity, the second opening having a second width that is different to the first width; wherein the support is configured to: support the expandable member within the second cavity, such that the expandable member extends out of the second opening; and abut the receptacle mould when the expandable member is expanded, such that the expandable member is expanded within the first cavity and the second cavity.
The system of claim 1, wherein the second width is greater than the first width.
3 The system of any of claims 1 or 2, wherein a wall thickness of a portion of the expandable member disposed at least partially within the second cavity is thicker than a wall thickness of a portion of the expandable member disposed within the first cavity, when the support abuts the receptacle mould
4. The system of any of claims 1 to 3, wherein the first opening comprises a fillet or chamfer edge.
S. The system of any of claims 1 to 4, wherein the second opening comprises a fillet or chamfer edge.
6. The system of any of claims Ito 5, wherein the second opening has an axis that is coaxial with an axis of the first cavity.
7. The system of any of claims 1 to 6, wherein the first opening and the second opening are the same shape.
8. The system of claim 7, wherein the first opening and the second opening are circular.
9. The system of any of claims I to 8, further comprising a fluid supply system configured to supply a fluid into the expandable member to maintain a pressure of between about 15 bar and about 25 bar within the expandable member.
10. The system of any of claims Ito 9, wherein the support is made of a rigid material.IS
11. A method of forming a receptacle in a receptacle mould, the receptacle mould comprising a first cavity and a first opening into the first cavity, the first opening having a first width, the method comprising: introducing a component into the first cavity of the receptacle mould, the component being a fibre suspension or a partially formed receptacle; moving a support towards the receptacle mould until the support abuts the receptacle mould, wherein the support: comprises a second cavity and a second opening into the second cavity, the second opening having a second width that is different to the first width; and supports an expandable member within the second cavity, such that the expandable member extends out of the second opening; introducing the expandable member into the first cavity via the first opening; and expanding the expandable member, such that the expandable member: expands within the first cavity to urge the component against an inner surface of the first cavity, thereby to help form the receptacle; and expands within the second cavity.
12 The method of claim 11, wherein the second width is greater than the first width
13. The method of claim 12, wherein the expanding the expandable member comprises: expanding the expandable member within the second cavity; and maintaining a distance between an inner wall of the support and an outer surface of the expandable member, at the second opening.
14. The method of claim 12 or claim 13, wherein the expanding the expandable member causes the expandable member to have a cross-sectional width within the second cavity that is wider than the first opening