Container mold and manufacturing method of container mold

Abstract

A container mold is disclosed that defines a cavity in which a container can be molded. The container mold includes a guide channel for guiding an expandable member into the cavity that can be used to aid in molding the container in the cavity. The guide channel has a first end and a second end, the second end opening into the cavity, and the expandable member is guideable through the guide channel from the first end to the second end and into the cavity. The guide channel has a first cross-sectional width at the first end and a second cross-sectional width at the second end, the second cross-sectional width being smaller than the first cross-sectional width.

Description

[Technical field]

[0001] The present invention relates to a container mold and a method for making the container mold. The container mold can be used to form a container from a fiber suspension, such as a fiber suspension containing paper pulp. The container can form a consumer package, such as a bottle, useful for holding liquids, powders, other flowable materials, or solid objects. [Background technology]

[0002] Bottles made from fibre suspensions are known and may be used to replace plastic bottles, thus reducing the amount of plastic used in disposable consumer products.

[0003] Published patent document WO 2018 / 020219 describes forming a bottle from paper pulp in a mold. A fiber suspension is introduced into the mold and a layer is deposited inside the mold. From here, a deflated "bladder" is introduced into the mold and allowed to expand. The expansion of the bladder forces the fiber suspension against the mold, forcing at least some of the water out of the fiber suspension, resulting in the formation of a bottle. This process of removing water is commonly known as "dewatering". [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 020219 Summary of the Invention

[0005] As mentioned above, the use of inflatable bladders (referred to herein as expandable members) in forming pulp molded containers is known. However, a problem with using these expandable members is that when the expandable members are first introduced into the mold cavity, they may contact and damage the delicate layer of fiber suspension that is spread throughout the inside of the mold. For example, as the expandable member passes through the mold opening, the expandable member (which is not expanded / inflated when it passes through) may fold upon contact with the mold and rebound and contact the layer of fiber suspension as the expandable member enters the cavity. This contact may cause the container to burst and / or cause the container wall to have an uneven thickness, compromising the structural integrity of the container.

[0006] To alleviate this problem, the inventors have designed a container mold with a "guide channel". The guide channel precisely guides an expandable member, such as an inflatable member, into the mold cavity to reduce or avoid contact with the fiber suspension layer coating the cavity surface. The guide channel has a specific form that guides the expandable member from outside the mold into the mold cavity. Thus, the guide channel extends from the outer surface of the mold into the cavity. Thus, a first end or a first portion of the guide channel is at the outer surface of the mold, and a second end of the guide channel is at the location where the guide channel opens into the cavity. In other examples, there is an additional portion of the guide channel between the first portion and the outer surface of the mold. In some examples, the additional portion of the guide channel has a width that is smaller than, equal to, or larger than the width of the first portion. In a first embodiment, the first opening (at the first end) of the guide channel is wider than the second opening (at the second end) of the guide channel. This means that the guide channel is narrowed along its length. In one example, the guide channel tapers along its length. By having a container mold with a guide channel that is wider at one end (such as the outer face / surface of the container mold) and narrower at the other end (that opens into the cavity), the expandable member can be guided into the mold cavity and kept away from the inner surface of the cavity. When the fiber suspension (from which the container is formed) is placed on the inner surface of the cavity, this can reduce the possibility of the expandable member damaging or interfering with the material during insertion of the expandable member.

[0007] Thus, according to a first aspect of the invention, there is provided a container mold defining a cavity within which a container is moldable, the container mold comprising a guide channel for guiding an expandable member into the cavity, the guide channel having (i) a first end and a second end, the second end opening into the cavity, the expandable member being guideable through the guide channel from the first end to the second end and into the cavity, (ii) a first cross-sectional width at the first end, and (iii) a second cross-sectional width at the second end, the second cross-sectional width being less than the first cross-sectional width.

[0008] In some cases, the cross-sectional width is a cross-sectional diameter.

[0009] The cross section may be taken on a plane parallel to the longitudinal axis of the container mold.

[0010] In some cases, the guide channel has a smoothly varying cross-sectional width. A smoothly varying cross-sectional width has no discontinuities. A guide channel having a stepped profile, for example, has discontinuities.

[0011] In some cases, the expandable member is supported by a support that moves the expandable member toward the mold to introduce the expandable member into the cavity. The support can be, for example, a "plug" that abuts against the mold when the expandable member is expanding. Thus, relative motion between the mold and the expandable member (and / or the support) guides the expandable member through the guide channel and into the cavity.

[0012] In certain examples, the container may be known as a molded container, an article, a bottle, a receptacle, a container for holding a fluid (such as a liquid) or a solid (such as a pharmaceutical or other tablet / capsule), an article for holding a fluid, a bottle for holding a fluid, a receptacle for holding a fluid, etc. The container may be molded from a fiber suspension that includes components such as paper pulp. The fiber suspension may contain, among other things, cellulosic fibers and a liquid such as water. Additives may be present in the fiber suspension.

[0013] The container may have a longitudinal axis along its length. The length / height of the container may be greater than the width and / or depth of the container. In some examples, the container may have a generally circular footprint due to the generally cylindrical shape of the container (along at least a portion of its length). In some examples, the container may have a square or squircle footprint.

[0014] The container mold (also called a mold) defines a cavity therein (also called a "mold cavity"), and a layer or coating of a fiber suspension may be applied to the interior walls of the cavity (the "mold cavity walls"). This initial layer / coating may have a first thickness, and after the expandable member is expanded, the layer / coating may have a second thickness that is less than the first thickness due to compression of the fibers and removal of some of the liquid.

[0015] In a particular example, the fiber suspension used to form the container is introduced into the cavity via a guide channel.

[0016] In some cases, instead of the fiber suspension, a partially formed container is introduced into the cavity. The partially formed container may be "unfinished" and may have been formed in a separate mold. An expandable member is used to press the partially formed container against the inner wall of the cavity as part of a drying (e.g., thermoforming) step. In some cases, the mold may be heated.

[0017] In some cases, the cavity has a body portion (also known as a first portion) and a neck portion (also known as a second portion). Both portions of the cavity together form the cavity. The neck portion can be used to form the neck of the container. A lid / cap can be attached to the end of the neck of the container, for example, later in the process of making the container. In some cases, the body portion has a cross-sectional width that is larger than the cross-sectional width of the neck portion (the cross-section is taken in a plane parallel to the longitudinal axis of the container mold).

[0018] A cavity or mold cavity is a portion of a mold that contains the entirety of a partially formed container, the entire container, or the entirety of a fiber suspension that is introduced into the cavity. Thus, a mold cavity contains a component entirely within it, the component being the fiber suspension or the partially formed container. Thus, any portion of the mold that contacts the component is not part of the guide channel, but is part of the cavity / cavity wall. In some cases, a portion of the mold cavity wall may not be in contact with the component, but may still be part of the cavity. That is, a mold cavity may be larger than the component contained within it. For example, between the second end of the guide channel and the component, there may be a portion of the cavity called the spacing portion of the cavity. The spacing portion does not contact the component, but is not part of the guide channel. Thus, when the second end of the cavity opens into the cavity, the second end may open into the spacing portion of the cavity.

[0019] In some cases, the mold is part of a split mold, which is made of two or more molds or "split parts". For example, the mold may form half (or a third, or a quarter, etc.) of a split mold, which may be joined with at least one other mold before receiving the fiber suspension therein. Thus, the mold cavity may form only a portion of the entire split mold cavity, and thus the cavity may be used to form only a portion of the outer surface of the molded container. In some cases, the molds forming the split mold may be identical, while in other cases they may be different.

[0020] In some cases, the cavity has an opening formed on / through the mold cavity wall, which allows liquid to pass from within the cavity to the outside of the mold. Thus, the opening may extend from the cavity to the exterior surface of the mold.

[0021] In one example, the mold is formed by 3D printing or other additive manufacturing techniques.

[0022] In a particular example, the container has a width (e.g., diameter) of about 65 mm to 70 mm, a height of about 190 mm to about 200 mm, and a volume of about 500 ml to 600 ml. In a further example, the container has a diameter of about 68 mm, a height of about 196 mm, and a volume of about 550 ml. The cavity may be sized accordingly.

[0023] In certain arrangements, the midpoint of the guide channel at the second end is coaxial with an axis (e.g., longitudinal axis) of the cavity, thereby ensuring that the expandable member is oriented toward the center of the cavity as it is introduced therein, thereby further mitigating the possibility of damage to the vessel formed within the cavity.

[0024] In some examples, the cavity has a third cross-sectional width where the second end of the guide channel opens into the cavity, the third cross-sectional width being at least about 4 mm greater than the second cross-sectional width. In one example, the third cross-sectional width is greater than the second cross-sectional width by about 4 mm to about 22 mm, e.g., about 11 mm to 15 mm, e.g., about 13 mm. Making the cavity at least 4 mm wider than the second end of the guide channel reduces the possibility of the expandable member contacting the fiber suspension or the vessel when the expandable member enters or is removed from the cavity. In some examples, the fiber suspension (or partially formed vessel) in the cavity has a particular wall thickness, and the third cross-sectional width is greater than the second cross-sectional width by at least 4 times the wall thickness. In certain examples, the third cross-sectional width is at least 2 mm greater than the average wall thickness of the fiber deposit than the second cross-sectional width. In some examples, the expandable member has a cross-sectional width narrower than the cross-sectional width of the guide channel at the second end. This therefore ensures that the distance between the expandable member and the fiber suspension (or partially formed vessel) is at least twice the wall thickness. In some cases, the expandable member has a cross-sectional width that is equal to or greater than the cross-sectional width of the guide channel at the second end.

[0025] In one example, the guide channel defines an overhang at the second end that reduces the possibility of the expandable member contacting the fiber suspension or vessel within the cavity when the expandable member is entering or removed from the cavity.

[0026] In some cases, the guide channel has an axis that is coaxial with the axis of the cavity. The axis can be, for example, a longitudinal axis. This means that the guide channel is centered with respect to the cavity, ensuring that the expandable member is centered in the cavity when it is inserted into the mold.

[0027] In some arrangements, the guide channel has a first cross-sectional shape at a first end and a second cross-sectional shape at a second end, the first cross-sectional shape and the second cross-sectional shape being the same. Having the first end and the second end having the same shape ensures that the expandable member does not twist or become unevenly deformed / compressed as it passes through the guide channel.

[0028] In certain arrangements, the first cross-sectional shape and the second cross-sectional shape are the same shape as a cross-sectional shape of the expandable member, thereby allowing the expandable member to pass more easily through the guide channel.

[0029] In one example, the first shape and the second cross-sectional shape are circular, meaning that there are no sharp edges that can damage the expandable member. The expandable member can also have a generally circular cross-sectional shape when unexpanded (i.e., contracted).

[0030] In some cases, the cavity has a third cross-sectional shape where the second end of the guide channel opens into the cavity, and the first cross-sectional shape, the second cross-sectional shape, and the third cross-sectional shape are the same, ensuring that the expandable member is more easily threaded into the cavity without being subjected to uneven forces because the guide channel and the cavity have the same shape.

[0031] In certain instances, the second end of the guide channel includes a filleted or chamfered edge where the second end opens into the cavity, such that the second end has a "smooth" edge that reduces the possibility of damaging the expandable member as it is inserted or removed from the cavity.

[0032] In some arrangements, the surface gradient along the guide channel gradient varies along its length. Having different gradients along the length of the guide channel allows the position of the expandable member to be controlled as it passes through the guide channel. Thus, in an example, the guide channel has a first surface gradient at a first point relative to an axis perpendicular to the axis of the container mold, and a second surface gradient at a second point relative to an axis perpendicular to the axis of the container mold, the first and second surface gradients being different, and the first point being closer to the first end than the second point. In some examples, the axis of the container mold may be a vertical axis.

[0033] The second point may be at or near the second end (such as less than 10 mm or less than 5 mm). The first point may be at or near the first end (such as less than 10 mm or less than 5 mm). In one example, the first point is at a midpoint along the length of the guide channel.

[0034] In certain instances, the second surface slope is greater than the first surface slope, with the shallower (first) surface slope facilitating the transition of the expandable member into the guide channel and the steeper (second) surface slope controlling the placement and trajectory of the expandable member into the cavity and reducing the likelihood of the expandable member contacting material within the cavity in which the vessel is formed.

[0035] In some examples, the surface slope along the guide channel varies smoothly. A smoothly varying surface slope has no discontinuities. The slope variation may be constant or non-constant. In certain examples, the surface slope along the guide channel varies smoothly rather than constant.

[0036] According to a second aspect of the invention, there is provided a method of manufacturing a container mold, the method may include (i) forming a cavity in the container mold, the cavity configured to mold a container, and (ii) forming a guide channel in the container mold, the guide channel having (a) a first end and a second end, the second end opening into the cavity, an expandable member being guideable through the guide channel from the first end to the second end and into the cavity, (b) a first cross-sectional width at the first end, and (c) a second cross-sectional width at the second end, the second cross-sectional width being less than the first cross-sectional width.

[0037] The mold may include any or all of the above and / or the following features.

[0038] In some examples, forming the cavity includes providing a cavity having a third cross-sectional width where the second end of the guide channel opens into the cavity, the third cross-sectional width being at least 4 mm greater than the second cross-sectional width.

[0039] In some examples, forming the guide channel includes providing a guide channel having a first cross-sectional shape at a first end and a second cross-sectional shape at a second end, where the first cross-sectional shape and the second cross-sectional shape are the same.

[0040] In a particular example, forming the cavity includes providing a cavity having a third cross-sectional shape where the second end of the guide channel opens into the cavity, and the first cross-sectional shape, the second cross-sectional shape, and the third cross-sectional shape are the same.

[0041] In some examples, forming the guide channel includes providing a second end of the guide channel with a filleted or chamfered edge where the second end opens into the cavity.

[0042] In some examples, forming the guide channel includes providing the guide channel with (i) a first surface slope at a first point relative to an axis perpendicular to the axis of the container mold, and (ii) a second surface slope at a second point relative to an axis perpendicular to the axis of the container mold, wherein the first surface slope and the second surface slope are different, and the first point is closer to the first end than the second point.

[0043] In the above embodiment, the container mold has a guide channel that is wider at one end than the other end. In another embodiment, the guide channel may not be wider at one end than the other end. For example, the two ends may have the same cross-sectional width, or the second end may be wider than the first end. In this embodiment, the guide channel and the cavity may be sized relative to each other such that when the expandable member enters the cavity, at the second end of the guide channel, there is a distance of at least twice the wall thickness of the fiber suspension (or partially formed container) between the surface of the cavity and the expandable member. Maintaining a distance of at least twice the wall thickness reduces the possibility that the expandable member will contact a component in the cavity, which may otherwise be disturbed or damaged (the component being, for example, the fiber suspension or partially formed container).

[0044] Thus, according to a third aspect of the present invention, there is provided a method of molding a container, the method comprising: (i) providing a container mold, the container mold having a cavity in which the container is moldable and a guide channel, the guide channel having a first end and a second end, the second end opening into the cavity; (ii) passing an expandable member through the guide channel and into the cavity, the cavity containing a component on a surface thereof, the component being a fiber suspension or a partially formed container, the component having a wall thickness; (iii) maintaining a distance of at least twice the wall thickness between a surface of the cavity and the expandable member at the second end of the guide channel as the expandable member is passed into the cavity; and (iv) expanding the expandable member to compress the component against the surface. In one example, the expandable member is an inflatable member, and expanding the expandable member comprises inflating the inflatable member.

[0045] The mold may include any or all of the above and / or the following features.

[0046] In some examples, the method further includes introducing the component into the cavity of the container mold. Introducing the component into the cavity of the container mold may include spraying / inserting / drawing a fiber suspension into the first mold. In some cases, the fiber suspension may be introduced under vacuum (i.e., a vacuum is applied to the mold or the first cavity). Introducing the component into the first cavity of the container mold may include inserting or placing a partially formed container into the first mold.

[0047] The surface of the cavity may be known as the cavity wall or mold cavity wall in some examples. The wall thickness may be the initial wall thickness before the expandable member is expanded. In examples where the expandable member has a cross-sectional width that varies along its length, the distance may be measured at the widest point of the expandable member (which will then be the minimum distance between the expandable member and the surface of the cavity).

[0048] Preferably, the distance is at least 2.5 times the wall thickness. Even more preferably, the distance is at least 3 times the wall thickness.

[0049] In one particular example, the guide channel has a first cross-sectional width at a first end and a second cross-sectional width at a second end, the second cross-sectional width being less than the first cross-sectional width. Thus, in a particular example, the guide channel also has a tapered configuration in addition to maintaining a precise distance between the cavity wall and the expandable member.

[0050] The mould of the third embodiment may have any or all of the features described above in relation to the first and second embodiments.

[0051] In a fourth aspect, a method of molding a container is provided, the method including: (i) providing a container mold having a cavity into which a container can be molded and a guide channel, the guide channel having (a) a first end and a second end, the second end opening into the cavity, and (b) a first cross-sectional width at the first end and a second cross-sectional width at the second end, the second cross-sectional width being smaller than the first cross-sectional width; (ii) passing an expandable member through the guide channel and into the cavity, the cavity housing a component on a surface thereof, the component being a fiber suspension or a partially formed container; and (iii) expanding the expandable member to compress the component against the surface.

[0052] The mold may include any or all of the above and / or the following features.

[0053] In a fifth aspect, there is provided a kit comprising a plurality of container moulds according to the first aspect, the plurality of container moulds being cooperable to mould a container. Thus, as described above, the moulds may be part of a split mould and may be joined to form a larger mould.

[0054] Further features and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, the description being made with reference to the accompanying drawings, in which:

[0055] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0056] [Figure 1] 1 shows an example of a process for producing an at least partially molded container from a fiber suspension. [Figure 2A] 1 shows a cross section of an exemplary mold before a fiber suspension is introduced into the mold cavity. [Figure 2B] 2B shows a top view of the container mold of FIG. 2A. [Diagram 3] 2B illustrates the exemplary mold of FIG. 2A after a fiber suspension has been introduced into the mold cavity. [Figure 4] 1 illustrates an exemplary flow diagram of a method for manufacturing a container mold. [Diagram 5] 1 shows an exemplary flow diagram of a method for forming a container. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] The following description presents exemplary embodiments and, together with the drawings, serves to explain the principles of the invention.

[0058] FIG. 1 illustrates a process for making a bottle from paper pulp (i.e., can form the basis of an exemplary fiber suspension). This process is merely exemplary and is provided to provide a context for the examples of the present invention. Broadly speaking, the exemplary process includes providing a fiber suspension, introducing the fiber suspension into a mold cavity of a porous first mold, using the porous first mold to expel liquid (such as water) from the fiber suspension to create a wet precursor or embryo (which may itself be considered a molded container), further molding the wet precursor with a mold to create a further molded container, coating the further molded container to create a coated molded container, drying the coated molded container to create a dried container, and applying a closure to the dried container. As will be apparent from at least the following description, the exemplary process can be modified to provide variations that may embody other examples of the present invention.

[0059] In this example, providing a fiber suspension includes preparing a fiber suspension from the components. More specifically, preparing includes providing pulp fibers, such as paper pulp fibers, and mixing the pulp fibers with a liquid to provide moist pulp fibers. In this example, the pulp fibers are provided in sheet form from a supplier, and the liquid includes water and one or more additives. In this example, the liquid is mixed with the pulp fibers to provide moist pulp fibers having a solid fiber content of 1 wt% to 5 wt% (by dry weight of the fibers). In an example, the one or more additives include a shortening agent, such as an alkyl ketene dimer (AKD). The moist pulp fibers typically include AKD in an amount of 0.4 wt% based on the total dry weight of the solid fibers in the moist pulp fibers. In some examples, the one or more additives are present in the liquid at the time of mixing the pulp fibers with the liquid. In some examples, the one or more additives are included with the wet pulp fibers after mixing the pulp fibers with a liquid (e.g., allowing the pulp fibers to hydrate for a period of time, e.g., 2-16 hours, and then feeding the one or more additives to the wet pulp fibers). The wet pulp fibers pass between plates of a valley beater 11 or refiner that are moving relative to one another. This fibrillates some or all of the fibers, meaning that the cell walls of those fibers are partially delaminated so that the wetted surfaces of the fibers contain protruding hairs or fibrillations. These fibrillations serve to increase the strength of the bonds between the fibers in the dried final product. In other examples, the valley beater 11 or refiner may be omitted.

[0060] The resulting treated pulp is stored in a tank 12 in a relatively concentrated form (e.g., solid fiber content of 1 wt% to 5 wt%) to reduce storage space required. At an appropriate time, the treated pulp is transferred to a mixing station 13 where the treated pulp is diluted with additional water and optionally mixed with one or more additives (along with or instead of the one or more additives provided with the wet pulp fibers) to provide a fiber suspension ready for molding. In this example, the solid fibers make up 0.7 wt% of the resulting fiber suspension (by dry weight of fiber), but in other examples the percentage of solid fibers in the fiber suspension may be different, such as 0.5 wt% to 5% wt, or another value in the range of 0.1 wt% to 1 wt% (by dry weight of fiber) of the fiber suspension. In some examples, the one or more additives mixed with the treated pulp and water include a dewatering agent. In some examples, the one or more additives are mixed with the water, and then the water and one or more additives are mixed with the treated pulp. In another example, the treated pulp and water are mixed and one or more additives are then mixed with the treated pulp and water. The fiber suspension typically includes a dewatering agent in an amount of 0.3 wt% based on the total dry mass of solid fibers. Mixing the fiber suspension at mixing station 13 helps to homogenize the fiber suspension. In another example, the treated pulp or fiber suspension may be provided in other ways, such as being supplied pre-made.

[0061] In this example, the porous first mold 15 includes two half molds that are movable toward and away from each other, in this case using a hydraulic ram. In this example, each of the half molds is a monolithic or unitary tool formed by additive manufacturing (e.g., 3D printing) that defines a mold profile, and when the half molds contact each other, their respective mold profiles cooperate to define a mold cavity in which the wet precursor or molded container is formed. Each half mold can itself define a smaller mold cavity, and when cooperating with the second half mold, the smaller mold cavities can combine to provide the overall mold cavity. The two half molds can themselves be considered as a "split part" or "mold" and the overall porous first mold 15 can be considered as a "split mold" or again as a "mold". In other examples, the porous first mold 15 can include two or more split parts, such as three, four, or six split parts that cooperate to define a mold cavity.

[0062] In FIG. 1, unlike the molding process where the mold is dipped into the slurry, the fiber suspension (also known as slurry) is filled into the porous mold 15 from the top. The fiber suspension is drawn into the porous mold 15 through line 16 under vacuum, and excess suspension is drawn through the porous mold 15 under vacuum through line 18 into tank 17. The shot mass may be controlled by measuring (e.g., weighing) the amount of liquid drawn into tank 17. A weight scale platform supporting tank 17 is shown in FIG. 1. Once the required amount of liquid (e.g., a predetermined volume, such as 10 liters, or a predetermined mass, such as 10 kilograms) has been collected in tank 17, the suction of suspension through the porous mold 15 is stopped and the porous mold 15 is opened to the surrounding air. In this example, the suspension drawn along with the fiber suspension in line 16 is water, or primarily water (additives may also be present). The liquid drawn into tank 17 through line 18 under vacuum is substantially fiber-free, as the fibers remain on the walls of the porous mold 15 to form the embryo of the molded vessel.

[0063] In one form, an impermeable expansion element 19, e.g., a collapsible bladder (also known as an expandable member), is inserted into the porous mold 15 and expanded to act as an internal high-pressure core structure of the porous mold 15 to remove further suspension (e.g., water) from the embryo and form or consolidate the three-dimensional shape of the vessel. This process strengthens the wet embryo so that it can be processed and displaces water from between the fibers, thereby improving the efficiency of the subsequent drying process. The expansion element 19 is actuated and regulated using a hydraulic pump 20. The pump 20 has a cylinder that displaces fluid in line 21 into the expansion element 19, causing it to radially expand and conform to the mold cavity. The fluid in line 21 is preferably incompressible, such as water. Water also has the advantage over other incompressible liquids that a leak or rupture of the bladder 19 does not introduce new material into the system (since the suspension is already water, or mainly water).

[0064] Demolding occurs when the porous mold 15 is opened to remove the self-supporting molded container 22. A mold wash 23 preferably follows to remove small fibers and maintain the porosity of the porous mold 15. In this example, a radially fired high pressure jet is inserted into the mold cavity while the mold 15 is open. This removes the fibers from the walls of the mold cavity. Alternatively or additionally, water from a tank 17 is pressurized through the back of the porous mold 15 to remove trapped fibers. The water is drained for recirculation to the upstream part of the system. It is noted that cleaning is important to condition the porous mold 15 for reuse. The porous mold 15 may appear clean after removal of the container, but its performance may be compromised if not cleaned.

[0065] According to FIG. 1, the formed but unfinished container 22 is then transferred to a second forming station where pressure and heat are applied, for example in an aluminum mold 25, for thermoforming the desired neck and optionally for surface finishing, including embossed and / or debossed surface features. After the two halves of the mold 25 are closed around the container 22, a pressurizer is engaged. For example, a bladder 26 (e.g., a thermoforming bladder 26) is inserted into the container 22. The bladder 26 is expanded by a pump 28 via a line 27, which supplies a pressurized fluid, for example air, water, or oil. Optionally, during the supply, the pressurized fluid is heated, for example by a heater, or alternatively cooled, for example by a heat exchanger. The outer mold block 24 of the mold 25 and / or the mold 25 itself may also be heated, or alternatively heated. The state of the formed container 22 after thermoforming is significantly stiffer and the side walls are more compressed, compared to the state upon demolding from the porous mold 15.

[0066] As shown, a drying step 29 (e.g., a microwave drying process or other drying process) occurs downstream of thermoforming. In one example, drying step 29 occurs prior to thermoforming. However, forming in mold 25 requires some moisture content to aid in bonding during the compression process. FIG. 1 shows a further drying step 30 after drying step 29, which may utilize hot air circulated over the formed container 22, for example, in a "hot box." In some examples, microwave or other drying processes may occur at multiple stages in the overall manufacturing process.

[0067] The molded container 22 is then subjected to a coating step during which, in this example, a spray lance 31 is inserted into the molded container 22 to apply one or more surface coatings to the inner walls of the molded container 22. In another example, the molded container 22 is instead filled with a liquid that coats the inner walls of the molded container 22. In practice, such coatings provide a protective layer to prevent the release of contents to the bottle walls that may penetrate and / or weaken the bottle walls. The coating is selected depending on the intended contents of the container 22, e.g., beverages, detergents, pharmaceuticals, etc. In some examples, an additional drying step 30 is performed after the coating step (or both before and after the coating step). In this example, the molded container 22 is then subjected to a curing process 34, which can be configured or optimized depending on the coating, e.g., dried at ambient conditions for 24 hours or dried by an air flow drying method. In some examples, the curing process 34 may be omitted, e.g., if the additional drying step 30 is performed after the coating step.

[0068] At an appropriate stage of production (e.g., during thermoforming, or before or after coating), a process may be performed to form a closure or mouth on the formed container 22. For example, a neck stuffer 35 may be attached as shown in FIG. 1. In some examples, an exterior coating is applied to the formed container 22 as shown in additional coating stage 32. In one example, the formed container 22 is immersed in a liquid that coats its exterior surface as shown in FIG. 1. One or more additional drying or curing processes may then be performed. For example, the formed container 22 may be dried in warm air. Thus, the formed container 22 may be fully formed and ready to receive contents therein.

[0069] FIG. 2A shows a cross-section of an exemplary mold 15. Mold 15 may be used in place of either or both of molds 15, 25 shown in FIG. 1. Mold 15 may be porous in some examples. FIG. 2A shows mold 15 before a fiber suspension is introduced into mold 15. FIG. 2B shows a top view of mold 15. FIG. 3 (described below) shows the mold of FIG. 2A after an expandable member 56 has been introduced into mold 15.

[0070] More specifically, Figure 2A shows a mold 15 or "split mold" formed from two separate mold halves or "pieces." Each mold half may itself be referred to as a mold in certain examples, and each mold half may define a cavity having mold cavity walls to which the fiber suspension may be applied. When the two mold halves are joined, the two cavities form a larger cavity 36 in mold 15. In other examples, mold 15 may be made from one piece rather than two pieces, or may be made from more than two pieces.

[0071] The cavity 36 of the mold 15 includes mold cavity walls 40 (i.e., the cavity 36 has an interior wall). The cavity 36 includes openings (not shown) that allow liquid to pass through, and thus the mold 15 is porous. The openings extend from the mold cavity walls 40, through the mold 15, to the outer surface of the mold. In other examples, the cavity 36 is non-porous. In FIG. 2A, the cavity 36 is "empty" because no fiber suspension has yet been provided to the mold 15.

[0072] 2A, cavity 36 (and each cavity of the mold halves) has a body portion 36a (also known as a first portion) and a neck portion 36b (also known as a second portion). Neck portion 36b can be used to form the neck of a container / bottle.

[0073] The mold 15 also has a guide channel 38. The expandable member 56 (shown in FIG. 3) can be introduced into the mold 15 (or more specifically into the cavity 36) through the guide channel 38. Similarly, the fiber suspension can be introduced into the mold 15 through the guide channel 38. FIG. 2B shows the guide channel 38 from above, which is closed around its periphery to form an opening into the mold 15. Each half mold may have a guide channel that is open around its periphery, and thus the guide channel 38 is closed only around its periphery when cooperating with one or more other molds to form a split mold, as in the example of FIGS. 2A and 2B. For example, FIG. 2B shows more clearly that the mold 15 consists of two half molds (each including a guide channel) that are joined to close the guide channel 38.

[0074] As shown, the guide channel 38 has a first (outer) end 38a and a second (inner) end 38b. The first end 38a opens to the outer surface 15a (or upper surface) of the mold 15, and the second end 38b opens into the cavity 36. Thus, the first end 38 is formed on the outer surface 15a of the mold 15. The guide channel 38 extends between the outer surface 15a and the cavity 36, or more specifically, between the outer surface 15a and the neck portion 36b of the cavity 36. Thus, when the expandable member 56 is introduced into the cavity 36, it passes from the first end 38a to the second end 38b and enters the cavity 36. In other words, the expandable member 56 is passed through the cavity 36 via the first end 38a to the second end 38b.

[0075] In this example, the guide channel 38 has a first cross-sectional width 42 at a first end 38a and a second cross-sectional width 44 at a second end 38b, where the first cross-sectional width 42 is greater than the second cross-sectional width 44. As previously mentioned, the guide channel 38 in this example has a tapered / funnel shape that guides the expandable member 56 into the cavity 36, thereby mitigating the possibility of the expandable member 56 contacting the fiber suspension layer (or reservoir) contained within the cavity 36.

[0076] In this example, the first cross-sectional width 42 is between about 38 mm and about 47 mm, and the second cross-sectional width 44 is between about 25 mm and about 34 mm. In this example, the first cross-sectional width 42 is 38 mm, and the second cross-sectional width 44 is 25 mm.

[0077] In the example of FIG. 2A, the cavity 36 (or more specifically, the neck portion 36b) has a third cross-sectional width 46 where the cavity 36 meets the second end 38b of the guide channel 38. Here, the third cross-sectional width 46 is greater than the second cross-sectional width 44 to ensure that the expandable member 56 is sufficiently spaced from the fiber suspension or vessel when it is inserted into and removed from the cavity 36. In an example, the third cross-sectional width 46 is about 38 mm to about 47 mm. In this example, the third cross-sectional width 46 is 38 mm.

[0078] In the example of FIG. 2A, the third cross-sectional width 46 is smaller than the first cross-sectional width 42, but in other examples, the third cross-sectional width 46 is larger than the first cross-sectional width 42, or they may be the same size.

[0079] In this particular example, the axis 48 (e.g., longitudinal axis) of the guide channel 38 is coaxial with the axis 50 (e.g., longitudinal axis) of the cavity 36. Thus, the first end 38a and the second end 38b of the guide channel 38 are centered above the cavity 36 such that when the expandable member 56 enters the cavity 36 through the opening, the expandable member 56 is inserted at the midpoint / center of the cavity 36 (i.e., the expandable member 56 is equidistant from the cavity wall 40).

[0080] As shown most clearly in FIG. 2B, the guide channel 38 has a first cross-sectional shape at a first end 38a and a second cross-sectional shape at a second end 38b, both having the same shape (in this case, the first cross-sectional shape and the second cross-sectional shape are both circular). The cavity 36 has a third cross-sectional shape where the second end 38b of the guide channel 38 opens into the cavity 36, the third cross-sectional shape being the same shape as the second cross-sectional shape and the third cross-sectional shape. The shape of the cavity at the opening into the cavity 36 is shown by the dashed line 52 in FIG. 2B. Again, the opening into the cavity 36 at the second end 38b is circular.

[0081] 2A and 2B, the second end 38b of the guide channel 38 includes a fillet edge 54 (i.e., a rounded, smooth edge) around the perimeter of where the second end 38b opens into the cavity 36. This reduces the chance of damaging the expandable member 56 as it is inserted into and removed from the cavity 36.

[0082] In a particular example, the guide channel 38 has a non-constant surface slope along its length. As shown in FIG. 2A, the surface slope varies smoothly along the length of the guide channel 38. For example, at a first point (point A in FIG. 2A), the guide channel 38 has a first surface slope relative to an axis (such as perpendicular to axis 48 and / or axis 50) perpendicular to the axis (e.g., longitudinal axis) of the container mold. Similarly, at a second point (point B), the guide channel 38 has a second surface slope relative to an axis perpendicular to the axis of the container mold. Here, the first point (point A) is closer to the first end 38a than the second point (point B) as measured in a direction along the axis of the container mold. As shown, the first surface slope is shallower than the second surface slope. In one particular example, the first surface slope is about 45 degrees and the second surface slope is greater than 45 degrees, such as about 50 degrees, 60 degrees, 70 degrees, or 80 degrees. A shallower slope allows for easier transition of the expandable member 56 into the guide channel 38, while a steeper (second) surface slope controls placement and trajectory of the expandable member 56 into the center of the cavity 36 and reduces the chance of the expandable member 56 contacting the cavity wall 40. A variable slope along the guide channel 38 can reduce wear on the expandable member as it contacts the mold 15. For reference, the surface slope of the surface may be 90 degrees.

[0083] Figure 3 shows the mould 15 at a later point in time. Now, fibre suspension 58 has been poured / pulled into the cavity 36 (possibly under vacuum) via the guide channels 38, with the fibre suspension 58 coating the mould cavity walls 40 to form a loose container shape. The liquid may be extracted or drained through openings (if present). At this point, the fibre suspension coating / layer 58 has an (initial) wall thickness 60 on the cavity walls 40. In examples, the wall thickness 60 is from about 2mm to about 8mm. In this example, the fibre suspension wall thickness 60 is about 4mm.

[0084] After the fiber suspension is applied to the mold cavity wall 40, the expandable member 56 is introduced into the cavity 36 and expanded to press / compress the fiber suspension layer 58 and help expel the liquid. This liquid may then pass through the openings (if present), possibly under vacuum. FIG. 3 shows the expandable member 56 in a non-expanded state and before it is expanded within the cavity 36. The expandable member 56 may be the expandable member 19 or 26 shown in FIG. 1. The expandable member 56 may be connected at one end to and supported by a support (shown in FIG. 1). After expansion / expansion, the fiber suspension coating / layer 58 has a second wall thickness on the cavity wall 40, the second wall thickness being less than the initial wall thickness 60. In an example, the second wall thickness (after compression) is about 0.5 mm to about 2 mm.

[0085] As shown most clearly in FIG. 3, the mold 15 is constructed such that the distance 62 between (i) the cavity wall 40 at the second end 38b of the guide channel 38 and (ii) the edge of the opening of the second end 38b into the cavity 36 is at least twice the wall thickness 60 of the fiber suspension 58 in the cavity 36. For example, in FIG. 3, the distance 62 is about three times the wall thickness 60. This distance 62 may be known as the size of the overhang or shoulder or notch between the opening of the second end 38b and the cavity wall 40. This means that the distance 64 between (i) the cavity wall 40 at the second end 38b of the guide channel 38 and (ii) the expandable member 56 (at its widest point) is also at least twice the wall thickness 60 of the fiber suspension 58 in the cavity 36.

[0086] Thus, when the expandable member 56 is introduced into the cavity, there is a distance 64 between the cavity wall 40 and the expandable member 56 at the second end 38b of the guide channel 38 that is at least twice the wall thickness 60.

[0087] Thus, with reference to both Figures 2A and 5, it can be inferred that the third cross-sectional width 46 (i.e., the cross-sectional width of the cavity at the second end 38b) is at least four times greater than the second cross-sectional width 44 (i.e., the cross-sectional width of the guide channel 38 at the second end 38b) by the wall thickness 60.

[0088] In an example, the expandable member 56 has a cross-sectional width at its widest point (in an unexpanded state) of about 25 mm to about 100 mm. In this particular example, the expandable member 56 has a cross-sectional width at its widest point of about 70 mm. The expandable member 56 may have a cross-sectional width greater than the width of the second end in a resting / contracted state, but during insertion, the guide channel is narrowed such that the expandable member 56 is compressed in width to avoid contact with the fiber suspension.

[0089] 4 illustrates an exemplary method 200 of manufacturing a container mold 15, the method including, in block 202, forming a cavity 36 in the container mold 15, the cavity 36 configured to mold a container. In block 204, the method includes forming a guide channel 38 in the container mold 15, the guide channel 38 having (i) a first end 38a and a second end 38b, the second end 38b opening into the cavity 36, and an expandable member 56 guideable through the guide channel 38 from the first end 38a to the second end 38b and into the cavity 36. The guide channel 38 also has a first cross-sectional width 42 at the first end 38a and a second cross-sectional width 44 at the second end 38b, the second cross-sectional width 44 being smaller than the first cross-sectional width 42. Blocks 202 and 204 may be formed simultaneously or sequentially.

[0090] 5 illustrates an exemplary method 300 for molding a container 15, the method including, at block 302, providing a container mold 15 having a cavity 36 in which the container can be molded and a guide channel 38. The guide channel 38 has a first end 38a and a second end 38b, the second end 38b opening into the cavity 36. At block 304, the method includes passing an expandable member 56 through the guide channel 38 into the cavity 36, the cavity 36 containing a component on a surface thereof, the component being a fiber suspension 58 or a partially formed container, the component having a wall thickness 60. At block 306, the method includes maintaining a distance 64 between a surface of the cavity 40 and the expandable member 56 at the second end 38b of the guide channel 38 when the expandable member 56 enters the cavity 36, the distance 64 being at least twice the wall thickness 60. At block 308 , the method includes expanding the expandable member 56 to compress the component against the surface 40 .

[0091] In the examples of Figures 2A, 2B and 5, the component being introduced into the mould 15 has been described as being a fibre suspension. However, it will be appreciated that the same features and methods described above are applicable to examples in which the component being introduced into the cavity is a partially formed container. For example, the mould may be the second mould 25 described in Figure 1, such that the partially formed container is compressed by the expansion of the expandable member, rather than a relatively loose fibre suspension.

[0092] The above embodiments should be understood as illustrative examples of the present invention. Further embodiments of the present invention are envisioned. Of course, any feature described in connection with any one embodiment can be used alone or in combination with other features described, and can also be used in combination with one or more features of any other embodiment, or in any combination of any other embodiment. Moreover, equivalents and modifications not described above may be employed without departing from the scope of the present invention, as defined in the appended claims.

Claims

1. A container mold defining a cavity in which a container can be formed, the container mold comprising guide channels for guiding an expandable member into the cavity which can be used to assist in the molding of the container within the cavity, The aforementioned guide channel is A first end and a second end, the second end opening into the cavity, and the expandable member being guided from the first end to the second end and into the cavity through the guide channel, The first end has a first cross-sectional width, A container mold having a second cross-sectional width smaller than the first cross-sectional width at the second end.

2. The cavity has a third cross-sectional width at the location where the second end of the guide channel opens into the cavity. The container mold according to claim 1, wherein the third cross-sectional width is at least 4 mm larger than the second cross-sectional width.

3. The container mold according to claim 1 or 2, wherein the guide channel has an axis that is coaxial with the axis of the cavity.

4. The guide channel has a first cross-sectional shape at the first end, The guide channel has a second cross-sectional shape at the second end, The container mold according to claim 1 or 2, wherein the first cross-sectional shape and the second cross-sectional shape are the same.

5. The cavity has a third cross-sectional shape at the location where the second end of the guide channel opens into the cavity. The container mold according to claim 4, wherein the first cross-sectional shape, the second cross-sectional shape, and the third cross-sectional shape are the same.

6. The container mold according to claim 1 or 2, wherein the second end of the guide channel is provided with a fillet edge or a chamfered edge at the location where the second end opens into the cavity.

7. The container mold according to claim 1 or 2, wherein the guide channel has, at a first point, a first surface gradient with respect to an axis perpendicular to the axis of the container mold, and at a second point, a second surface gradient with respect to an axis perpendicular to the axis of the container mold, wherein the first surface gradient and the second surface gradient are different, and the first point is closer to the first end than the second point.

8. The container mold according to claim 7, wherein the second surface gradient is greater than the first surface gradient.

9. A method for manufacturing a container mold, The cavity of the container mold is configured to form the cavity for molding the container, To form a guide channel in the container mold and The guide channel includes, A first end and a second end, the second end opening into the cavity, and an expandable member being guided from the first end to the second end and into the cavity through the guide channel, The first end has a first cross-sectional width, The second end has a second cross-sectional width smaller than the first cross-sectional width and A method having.

10. The method according to claim 9, wherein forming the cavity includes providing the cavity having a third cross-sectional width at a location where the second end of the guide channel opens into the cavity, the third cross-sectional width being at least 4 mm larger than the second cross-sectional width.

11. Forming the guide channel means that the guide channel The first cross-sectional shape at the first end, The method according to claim 9 or 10, comprising providing a second cross-sectional shape at the second end, wherein the first cross-sectional shape and the second cross-sectional shape are the same.

12. The method according to claim 11, wherein forming the cavity includes providing the second end of the guide channel in the cavity having a third cross-sectional shape at a location where it opens into the cavity, and the first cross-sectional shape, the second cross-sectional shape, and the third cross-sectional shape are the same.

13. The method according to claim 9 or 10, wherein forming the guide channel includes providing a fillet edge or chamfered edge at the second end of the guide channel at a location where the second end opens into the cavity.

14. Forming the guide channel means that the guide channel At the first point, the first surface gradient with respect to an axis perpendicular to the axis of the container mold, In the second point, the second surface gradient of the container mold with respect to the axis perpendicular to the axis and The method according to claim 9 or 10, comprising, wherein the first surface gradient and the second surface gradient are different, and the first point is closer to the first end than the second point.

15. A method for forming a container, To provide a container mold, wherein the container mold has a cavity into which a container can be molded and a guide channel, the guide channel has a first end and a second end, the second end opening into the cavity, Passing an expandable member through the guide channel into the cavity, wherein the cavity contains a component on its surface, the component being a fiber suspension or a partially formed container, and the component having wall thickness, through the expandable member. When the expandable member passes through the cavity, the second end of the guide channel maintains a distance of at least twice the wall thickness between the surface of the cavity and the expandable member. A method comprising expanding the expandable member to compress the component relative to the surface.

16. A method for forming a container, To provide a container mold, the container mold having a cavity into which a container can be molded and a guide channel, the guide channel is A first end and a second end, the second end opening into the cavity, the first end and the second end, To provide a container mold having a first cross-sectional width at the first end and a second cross-sectional width at the second end, wherein the second cross-sectional width is smaller than the first cross-sectional width, Passing an expandable member through the guide channel into the cavity, the cavity having a component on its surface, the component being a fiber suspension or a partially formed container, and passing the expandable member through the cavity. A method comprising expanding the expandable member to compress the component relative to the surface.

17. A kit comprising a plurality of container molds according to claim 1 or 2, wherein the plurality of container molds are cooperatively capable of forming the containers.

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