Method and molding system

Abstract

A method of molding a container is described. The method comprises the following steps: providing a mold; providing a partially shaped container within the mold; providing an expandable member within the partially shaped container (in a first configuration); moving the expandable member (in the first configuration) into contact with a base of the partially shaped container such that the expandable member deforms toward a perimeter of the base of the partially shaped container; and injecting a fluid into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration so as to urge the partially shaped container against an inner surface of the mold during the process of forming the container from the partially shaped container.

Description

Technical Field

[0001] The present invention relates to a method for molding a container and a molding system. Background Art

[0002] There is a desire to reduce the use of plastic in consumer products, particularly packaging. Trays and other simple shapes are often made from pulp, but making more complex objects such as bottles is more difficult. For example, it can be difficult to ensure that the pulp is compacted within the mold to form the bottle. Undercompaction can result in weak spots on the bottle. Summary of the invention

[0003] According to a first aspect of the present invention, a method for molding a container is provided. The method includes: providing a mold; providing a partially formed container in the mold; providing an expandable member (in a first configuration) in the partially formed container; moving the expandable member (in the first configuration) into contact with the base of the partially formed container so that the expandable member deforms toward the periphery of the base of the partially formed container; and injecting a fluid into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration, so as to drive the partially formed container against the inner surface of the mold during the process of forming the container from the partially formed container.

[0004] With respect to methods of expanding an expandable member to form a container without first deforming the expandable member toward the periphery of the base of the partially formed container, friction generated at the point where the expandable member initially contacts the partially formed container may inhibit further expansion of the expandable member into the periphery. This may result in undercompacting the periphery, which in turn may result in a weak point in the container.

[0005] Alternatively or additionally, such friction may result in uneven stretching of the expandable member. For example, portions of the expandable member that are not restrained by friction may overstretch to compensate for portions of the expandable member that are restrained by friction. Such overstretching may cause damage or fatigue to the expandable member. Deforming the expandable member toward the periphery before expanding the expandable member to form a container can mitigate these factors. Specifically, the expandable member may be more likely to expand into the periphery of the base of the partially formed container compared to methods that do not deform the expandable member toward the periphery before expanding the expandable member to form a container. This can reduce the presence of weak points in the container caused by insufficient compaction of the material from which the container is made. Additionally or alternatively, the expandable member may be more likely to stretch in a uniform manner and thereby reduce the possibility of damage or fatigue due to overstretching. As a result, the life of the expandable member can be improved.

[0006] Optionally, the first configuration is the natural resting state of the expandable member (e.g., a state in which no radially inward or outward pressure is applied to the expandable member, and / or a state in which no negative or positive pressure is applied to the interior of the expandable member). Alternatively, the first configuration is a state in which a certain positive pressure has been applied to the interior of the expandable member to expand the expandable member from its natural resting state.

[0007] Optionally, the container is a bottle.

[0008] Optionally, the expandable member is moved into contact with the base so that the distance between the expandable member and the periphery of the base of the partially formed container is no greater than 50% of the radius of the base of the partially formed container. Thus, the portion of the expandable member that expands into the periphery of the base of the partially formed container will be located closer to the periphery than when the distance is greater than 50%. Thus, the expandable member may be more likely to expand into the periphery of the base of the partially formed container, and the occurrence of weak points in the container may be reduced thereby. In addition, the pressure applied by the expandable member to the partially formed container when the expandable member expands to the second configuration may be more evenly distributed than when the distance is greater than 50%. In addition, by making the distance no greater than 50%, the strain within the expandable member may be reduced and the life of the expandable member may be increased thereby, compared to when the distance is greater than 50%.

[0009] Optionally, the partially formed container includes a side and a corner, the corner connecting a portion of the perimeter of the base of the partially formed container to the side of the partially formed container. Optionally, the corner of the partially formed container has a first radius of curvature. Optionally, the expandable member includes a corner, the corner is adjacent to the corner of the partially formed container before the fluid is injected into the expandable member to further expand the expandable member. Optionally, the expandable member is moved into contact with the base so that the corner of the expandable member has a second radius of curvature that is not greater than 130% of the first radius of curvature and not less than 70% of the first radius of curvature. Therefore, before the expandable member is expanded to form the container, the shape of the expandable member adjacent to the corner of the partially formed container is substantially the same as the corner of the partially formed container. Compared with the second radius other than these values, this can increase the probability that the expandable member will conform to the shape of the corner of the partially formed container when expanded. This improved consistency can improve the compaction of the partially formed container in the corner, thereby reducing the occurrence of weak points.

[0010] Optionally, the expandable member is moved into contact with the base such that the second radius of curvature is no greater than 110% and no less than 90% of the first radius of curvature.

[0011] Optionally, there is a gap between the expandable member and the side of the partially formed container before or during the movement of the expandable member into contact with the base of the partially formed container. Thus, the likelihood of the expandable member rubbing against and damaging the side of the partially formed container during movement of the expandable member before the expandable member is expanded to form the container can be reduced compared to methods where there is no gap between the expandable member and the side of the partially formed container.

[0012] Optionally, the gap is measured along the gap axis and is not less than the thickness of the wall of the expandable member measured along the gap axis. Thus, the likelihood of friction can be reduced compared to a gap that is less than the measured thickness of the wall of the expandable member.

[0013] Optionally, the gap is measured along the gap axis, and the gap is no greater than 4 times the thickness of the wall of the expandable member measured along the gap axis. Thus, compared to a gap greater than 4 times the thickness of the wall of the expandable member, a wider expandable member can be used, which can increase the likelihood that the expandable member can expand into the base periphery of a partially formed container. Specifically, achieving a gap greater than 4 times the thickness of the wall of the expandable member may require the use of a thinner expandable member.

[0014] Optionally, the container includes a neck, and the expandable member is moved into contact with the base of the container so that the expandable member is deformed into contact with the neck of the container. Thus, a high friction area can be created between the neck and the expandable member, which can anchor the expandable member relative to the container. Thus, the likelihood of the expandable member moving away from the base of the container during subsequent expansion of the expandable member can be reduced when compared to a process where the neck is not contacted by the expandable member. This can improve compaction of the base of the container and thereby reduce the likelihood of weak points in the container.

[0015] Optionally, the mold includes an opening. Optionally, providing the expandable member in the first configuration within the partially formed container includes: providing the expandable member in a third configuration outside the mold, in which the expandable member is less expanded than when in the first configuration; inserting the expandable member in the third configuration into the mold via the opening; and injecting a fluid into the expandable member to expand the expandable member from the third configuration to the first configuration. Inserting the expandable member in the third (less expanded) configuration can enable a wider expandable member to be inserted into the partially formed container without damaging the expandable member or the partially formed container during insertion when compared to inserting the expandable member in the first configuration. The wider expandable member can increase the likelihood that the expandable member will expand into the periphery, and thereby reduce the occurrence of weak points in the container.

[0016] Subsequent expansion of the expandable member from the third configuration to the first configuration may increase the extent to which the expandable member may deform toward the periphery of the base of the container. For example, if the expandable member is collapsed to enable insertion into the opening and then not expanded prior to contacting the base of the container, the collapsed expandable member may be less likely to deform toward the periphery of the base of the container.

[0017] Optionally, the method comprises withdrawing the expandable member from the mold via the opening after the process of forming the container from the partially formed container. Thus, the expandable member can be reused to mold multiple containers, which can reduce the cost of the molding process using the method.

[0018] Optionally, while in the third configuration, negative pressure is applied to the interior of the expandable member, causing the expandable member to collapse.

[0019] Optionally, the method includes providing a mandrel that is at least partially located within the expandable member. Providing a mandrel can provide structural support to the expandable member, which can help to properly position the expandable member before expanding the expandable member to form a container. As a result, the likelihood that the expandable member will expand into the periphery of the base of the partially formed container during expansion of the expandable member to form a container may be increased compared to a method that does not provide a mandrel.

[0020] Optionally, the mandrel includes one or more holes such that a fluid can flow from the interior of the mandrel through the one or more holes to the exterior of the mandrel to expand the expandable member.

[0021] Optionally, the method includes at least one of: rotating the mandrel relative to the mold to twist the expandable member around the mandrel to reduce the width of the expandable member; and rotating the mandrel relative to the mold to untwist the expandable member around the mandrel to increase the width of the expandable member. Thus, the width of the expandable member can be changed. Thus, the width of the expandable member can be reduced to facilitate the expansion of the expandable member through the opening, and then the width can be increased to achieve expansion of the expandable member to form a container. Beneficially, this can enable a wider expandable member to be adopted than is feasible without twisting the expandable member. A wider expandable member can increase the likelihood that the expandable member will expand into the periphery, and thereby reduce the occurrence of weak points in the container.

[0022] Optionally, the expandable member is attached to a mandrel, the method includes providing a connector for connecting the mandrel to the mold, the expandable member is attached to the connector, and the rotation of the mandrel is performed relative to the connector.

[0023] Optionally, the method includes moving the mandrel to change the width of the expandable member. Thus, the width of the expandable member can be reduced to facilitate the expansion of the expandable member through the opening, and then the width can be increased to achieve expansion of the expandable member to form the container. Beneficially, this can enable a wider expandable member to be used than is feasible without changing the width of the expandable member. A wider expandable member can increase the likelihood that the expandable member will expand into the periphery, and thereby reduce the occurrence of weak points in the container.

[0024] Optionally, the expandable member is attached to a mandrel, the method comprising providing a connector for connecting the mandrel to the mold, the expandable member being attached to the connector, and the mandrel being movable relative to the connector.

[0025] Optionally, the partially formed container is at least partially formed from paper pulp. Paper is chosen to be more eco-friendly than plastic. However, when formed from paper pulp, the container is particularly susceptible to weak points due to insufficient compaction. By deforming the expandable member toward the periphery of the base of the partially formed container before expanding the expandable member to form the container, the expandable member may be more likely to expand into the periphery than a method that does not deform the expandable member toward the periphery before expanding the expandable member to form the container. This can reduce the likelihood of the container having weak points due to insufficient compaction.

[0026] Optionally, the method includes applying heat to the partially formed container during the injection of fluid into the expandable member to further expand the expandable member. Thus, a thermoforming operation is applied to the partially formed container. Thermoforming can improve the mechanical properties of the container, such as stiffness, and the surface finish of the container.

[0027] Optionally, the partially formed container is at least partially formed of pulp, the mold is heated to heat the partially formed container, and the duration between moving the expandable member into contact with the base of the partially formed container and injecting the fluid into the expandable member to expand the expandable member from the first configuration to the second configuration is no more than 1 second. When the expandable member contacts the base of the partially formed container, some of the pulp at the base can be pushed into the mold by the expandable member. As the mold is heated, water in the pulp at the base can flash into steam. The steam can apply pressure to the outside of the base of the container. If the expandable member is only in the first configuration when this flash occurs, the expandable member may not be able to apply enough pressure to the inside of the base of the container to counteract the pressure applied by the steam. This may cause damage to the pulp, which may cause a weak point in the container. By expanding the expandable member less than 1 second after moving the expandable member into contact with the base, the expandable member can expand in time to apply enough pressure to counteract the pressure applied by the steam when compared with a longer duration between operations, and thereby reduce the possibility of such damage occurring.

[0028] Optionally, the duration is no greater than 0.9 seconds. Optionally, the duration is no greater than 0.75 seconds. Optionally, the duration is no greater than 0.5 seconds.

[0029] According to a second aspect of the present invention there is provided a container obtainable or obtained from a method of manufacture comprising a method according to the first aspect of the present invention.

[0030] Optionally, the method of making comprises at least one additional process. Optionally, at least one additional process comprises coating and drying the container to produce a coated container. Optionally, at least one additional process comprises applying a closure to the container or the coated container.

[0031] Optionally, the container is a bottle.

[0032] According to a third aspect of the present invention, a molding system is provided, comprising a mold for receiving a partially formed container, an expandable member, a pump connected to the expandable member by a fluid, and a controller. When the expandable member is in a first configuration and provided in the partially formed container, the controller is configured to move the expandable member into contact with the base of the partially formed container, so that the expandable member deforms toward the periphery of the base of the partially formed container, and to cause the pump to inject fluid into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration, so as to drive the partially formed container against the inner surface of the mold during the process of forming the container from the partially formed container.

[0033] Optionally, the partially formed container is a partially formed bottle.

[0034] Optionally, the first configuration is the natural resting state of the expandable member (e.g., a state in which no radially inward or outward pressure is applied to the expandable member, and / or a state in which no negative or positive pressure is applied to the interior of the expandable member). Alternatively, the first configuration is a state in which a certain positive pressure has been applied to the interior of the expandable member to expand the expandable member from its natural resting state.

[0035] Optionally, the controller is configured to insert the expandable member in a third configuration into the mold via the opening of the mold, in which the expandable member is less expanded than when in the first configuration, and cause the pump to inject fluid into the expandable member to expand the expandable member from the third configuration to the first configuration. Inserting the expandable member in the third (less expanded) configuration can enable a wider expandable member to be inserted into a partially formed container without damaging the expandable member or the container during insertion when compared to inserting the expandable member in the second configuration. A wider expandable member can increase the likelihood that the expandable member will expand into the periphery and thereby reduce the presence of weak points in the container.

[0036] Optionally, while in the third configuration, negative pressure is applied to the interior of the expandable member, causing the expandable member to collapse.

[0037] Optionally, the controller is configured to cause the pump to inject fluid into the expandable member to expand the expandable member from the third configuration to the first configuration such that a gap exists between the expandable member and a side of the partially formed container.

[0038] Optionally, the gap is measured along the gap axis and is no less than the thickness of the wall of the expandable member measured along the gap axis. Optionally, the gap is measured along the gap axis and is no greater than 4 times the thickness of the wall of the expandable member measured along the gap axis.

[0039] Optionally, the controller is configured to move the expandable member into contact with the base of the partially formed container such that a distance between the expandable member and a perimeter of the base of the partially formed container is no greater than 50% of a radius of the base of the partially formed container.

[0040] Optionally, the partially formed container includes a side and a corner, the corner connecting a portion of the perimeter of the base of the partially formed container to the side of the partially formed container. Optionally, the corner of the partially formed container has a first radius of curvature. Optionally, the expandable member includes a corner, which is adjacent to the corner of the partially formed container before the controller causes the pump to inject fluid into the expandable member to expand the expandable member. Optionally, the controller is configured to move the expandable member into contact with the base of the partially formed container so that the corner of the expandable member has a second radius of curvature that is no greater than 130% of the first radius of curvature and no less than 70% of the first radius of curvature.

[0041] Optionally, the expandable member is moved into contact with the base such that the second radius of curvature is no greater than 110% and no less than 90% of the first radius of curvature.

[0042] Optionally, the molding system includes a mandrel at least partially located or partially positionable within the expandable member.

[0043] Optionally, the mandrel is rotatable relative to the expandable member to twist the expandable member about the mandrel.

[0044] Optionally, the molding system includes a connector for connecting the mandrel to the mold, the expandable member is attached to the connector, and the mandrel is rotatable relative to the connector.

[0045] Optionally, the mandrel can be moved to change the width of the expandable member.

[0046] Optionally, the molding system includes a connector for connecting the mandrel to the mold, the expandable member is attached to the connector, and the mandrel is movable relative to the connector.

[0047] Optionally, the molding system includes a heater, and the controller is configured to cause the heater to apply heat to the partially formed container during injection of fluid into the expandable member to expand the expandable member from the first configuration to the second configuration.

[0048] Optionally, the molding system is a pulp container molding system.

[0049] According to a fourth aspect of the present invention, a non-transitory storage medium is provided, which stores machine-readable instructions, a molding system including a mold and an expandable member in a first configuration located in a partially formed container, the machine-readable instructions, when executed by a processor of the molding system, causing the processor to perform the following operations: moving the expandable member into contact with the base of the partially formed container so that the expandable member deforms toward the periphery of the base of the partially formed container; and injecting fluid into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration, so as to drive the partially formed container against the inner surface of the mold during the process of forming a container from the partially formed container.

[0050] Optionally, the partially formed container is a partially formed bottle.

[0051] Where appropriate, optional features of one aspect of the invention may also be applied to other aspects of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0053] Figure 1 is a schematic diagram of an example process for making a bottle from pulp;

[0054] Figure 2 shows a simplified cross-sectional view of an example molding system;

[0055] Figure 3Different stages of operation of the molding system are shown by simplified cross-section, wherein: (a) a mandrel system of the molding system is located outside a mold of the molding system, and an expandable member of the mandrel system is in a third configuration; (b) a mandrel of the mandrel system is moved relative to a connector of the mandrel system to reduce a width of the expandable member; (c) the mandrel system is inserted into the mold; and (d) the expandable member is expanded from the third configuration to the first configuration;

[0056] Figure 4 An expandable member is shown, by simplified cross-section, being moved into contact with a base of a partially formed container located within a mold, causing the expandable member to deform;

[0057] Figure 5 showing an enlarged view of the expandable member being moved into contact with the base of the partially formed container; and

[0058] Figure 6 Different stages of operation of the molding system are shown by simplified cross-sections, wherein: (a) the expandable member is expanded from a first configuration to a second configuration to apply a forming operation to the partially formed container; (b) the expandable member is collapsed from the second configuration to a third configuration; (c) the connector and the mandrel are moved to reduce the width of the expandable member; and (d) the mandrel system is withdrawn from the mold. DETAILED DESCRIPTION

[0059] The following description presents exemplary embodiments and is related to the accompanying Figure 1 It is used to explain the principles of the embodiments of the present invention.

[0060] Figure 1 A process for making a bottle from pulp (i.e., which may form the basis of an example fiber suspension) is shown. The process is merely exemplary and is provided to give context to examples of the invention. Broadly speaking, the exemplary process includes: providing a fiber suspension; introducing the fiber suspension into a mold cavity of a porous first mold, and using the porous first mold to expel a liquid (such as water) from the fiber suspension to produce a wet precursor or embryo (which itself may be considered a molded container); further molding the wet precursor in a mold to produce a further molded container; coating the further molded container to produce a coated molded container; drying the coated molded container to produce a dry container; and applying a closure to the dry container. As will be apparent at least from the following description, the exemplary process may be modified to provide variations that may embody other examples of the invention.

[0061] In this example, providing a fiber suspension comprises: preparing a fiber suspension from the ingredients of the fiber suspension. More specifically, the preparation comprises: providing pulp fibers such as paper pulp fibers, and mixing the pulp fibers with a liquid to provide hydrated pulp fibers. In this example, the pulp fibers are provided by a supplier in sheet form and the liquid comprises water and one or more additives. In this example, the liquid is mixed with the pulp fibers to provide hydrated pulp fibers having a solid fiber content of 1 wt % to 5 wt % (based on the dry mass of the fibers). In an example, the one or more additives comprise a sizing agent such as alkyl ketene dimer (AKD). The hydrated pulp fibers typically comprise 0.4 wt % AKD relative to the total dry mass of solid fibers in the hydrated pulp fibers. In some examples, one or more additives are present in the liquid when the pulp fibers are mixed with the liquid. In some examples, one or more additives are included in the hydrated pulp fibers after mixing the pulp fibers with the liquid (e.g., the pulp fibers are hydrated for a period of time, such as 2 to 16 hours, and then the one or more additives are supplied to the hydrated pulp fibers). The hydrated pulp fibers are passed between plates that move relative to each other in a valley beater 11 or refiner. This causes some or all of the fibers to fibrillate, meaning that the cell walls of the fibers become partially stratified so that the wet surfaces of the fibers include protruding hairs or fibrillations. These fibrillations will help increase the bonding strength of the fibers in the dried final product. In other examples, the valley beater 11 or refiner may be omitted.

[0062] The resulting processed pulp is stored in a vat 12 in a relatively concentrated form (e.g., 1 wt % to 5 wt % solid fiber content) to reduce required storage space. At an appropriate time, the processed pulp is transferred to a mixing station 13 where it is diluted with additional water and optionally mixed with one or more additives (in addition or in lieu of being provided with the hydrated pulp fibers) to provide a fiber suspension ready for molding. In this example, solid fibers comprise 0.7 wt % of the resulting fiber suspension (based on the dry weight of the fibers), but in other examples, the proportion of solid fibers in the fiber suspension may vary, such as another value in the range of 0.5 wt % to 5 wt %, or 0.1 wt % to 1 wt % of the fiber suspension (based on the dry weight of the fibers). In some examples, the one or more additives mixed with the processed pulp and water include: a dewatering agent, such as modified and / or unmodified polyethyleneimine (PEI), for example, available under the trade name SK. In some examples, one or more additives are mixed with water, and then the water and one or more additives are mixed with the processed pulp; in other examples, the processed pulp is mixed with water, and then the one or more additives are mixed with the processed pulp and water. The fiber suspension typically contains 0.3% by weight of the total dry mass of solid fibers. SK. The mixing of the fiber suspension at the mixing station 13 helps to homogenize the fiber suspension. In other examples, the process pulp or fiber suspension may be provided in other ways, such as a ready-made supply.

[0063] In this example, the porous first mold 15 includes two half molds that can move toward and away from each other, in this case using a hydraulic ram. In this example, each of the half molds is an integral or single tool formed by additive manufacturing (e.g., 3D printing) that defines a mold contour, and when the half molds are brought into contact with each other, their respective mold contours cooperate to define a mold cavity in which a wet precursor or a molded container is to be formed. Each half mold itself can define a smaller mold cavity, and when cooperating with the second half mold, the smaller mold cavity can be combined to provide an overall mold cavity. The two half molds themselves can be regarded as "splits" or "molds", and the overall porous first mold 15 can be regarded as a "split mold" or equally a "mold". In other examples, the porous first mold 15 may include more than two split shells that cooperate to define a mold cavity, such as 3, 4 or 6 split shells.

[0064] exist Figure 1 In the process, the fiber suspension (also called slurry) is top-filled into the porous mold 15, which is the opposite of the molding process in which the mold is immersed in the slurry. The fiber suspension is sucked out through the pipeline 16 under vacuum and sucked out into the porous mold 15, wherein the excess suspension liquid is sucked out through the porous mold 15 under vacuum through the pipeline 18 into the storage tank 17. The shot mass can be controlled by measuring (e.g. weighing) the amount of liquid sucked into the storage tank 17. In Figure 1 1, a weighing scale platform supporting the reservoir 17 can be seen. Once the desired amount of liquid (e.g. a predetermined volume such as 10 liters, or a predetermined mass such as 10 kg) has been collected in the reservoir 17, the suction of the suspension liquid through the porous mold 15 is stopped and the porous mold 15 is opened to the ambient air. In this example, the suspension liquid sucked out in the line 16 together with the fiber suspension is water, or mainly water (because additives may also be present). The liquid sucked out under vacuum via the line 18 and into the reservoir 17 is substantially free of fibers, because these fibers are left on the walls of the porous mold 15 to form the embryo of the molded container.

[0065] In one form, in order to remove additional suspension liquid (e.g., water) from the embryo and form or strengthen the three-dimensional shape of the container, an impermeable expansion element 19, such as a collapsible bladder, is inserted into the porous mold 15 and expanded to act as an internal high-pressure core structure of the porous mold 15. This process strengthens the wet embryo so that it can be handled and displaces water from between the fibers, thereby improving the efficiency of the subsequent drying process. A hydraulic pump 20 is used to actuate and adjust the expansion element 19. The pump 20 has a cylinder that displaces the fluid in the pipeline 21 into the expansion element 19 so that the expansion element 19 expands radially and expands to be consistent with the mold cavity. The fluid in the pipeline 21 is preferably incompressible, such as water. Water also has the following advantages over other incompressible liquids: any leakage or bursting of the bladder 19 will not introduce new substances into the system (because the suspension liquid is already water, or mainly water).

[0066] Demolding occurs when the porous mold 15 is opened to remove the self-supporting molded container 22. Mold cleaning 23 is preferably performed subsequently to remove small fibers and maintain the porosity of the porous mold 15. In this example, a radially projected high-pressure jet is injected into the mold cavity when the mold 15 is opened. This will cause the fibers to break away from the walls of the mold cavity. Alternatively or additionally, water from a reservoir 17 is pressurized and passed through the back of the porous mold 15 to dislodge trapped fibers. The water is drained to circulate back to the upstream part of the system. It is worth noting that cleaning is important for conditioning the porous mold 15 for reuse. The porous mold 15 may look clean after removing the container, but not cleaning it may compromise its performance.

[0067] according to Figure 1 , the formed but unfinished container 22 is then transported to a second molding station where, in a mold 25 of, for example, aluminum, pressure and heat are applied to thermoform the desired neck and surface finish, optionally including embossed and / or concave surface features. After the two halves of the mold 25 are closed around the container 22, the intensifier is turned on. For example, a bladder 26 (e.g., a thermoforming bladder 26) is inserted into the container 22. The bladder 26 is inflated by a pump 28 via a line 27 to supply a pressurized fluid, such as air, water, or oil. Optionally, during supply, the pressurized fluid is heated, for example, with a heater, or alternatively, cooled, for example, with a heat exchanger. The outer mold block 24 of the mold 25 and / or the mold 25 itself may also or alternatively be heated. The state of the molded container 22 after thermoforming is significantly more rigid with a more compressed sidewall than when it was demolded from the porous mold 15.

[0068] As shown, a drying stage 29 (e.g., a microwave drying process or other drying process) is performed downstream of the thermoforming. In one example, the drying stage 29 is performed before the thermoforming. However, molding in the mold 25 requires a certain water content to facilitate bonding during the compression process. Figure 1 An additional drying stage 30 is shown following drying stage 29, which may utilize hot air circulated over molded container 22, such as in a "hot box." In some examples, microwave or other drying processes may be performed at multiple stages of the overall manufacturing process.

[0069] The molded container 22 is then subjected to a coating phase, during which, in this example, a spray gun 31 is inserted into the molded container 22 and one or more surface coatings are applied to the inner wall of the molded container 22. In another example, the molded container 22 is instead filled with a liquid that coats the inner wall of the molded container 22. In fact, such coatings provide a protective layer to prevent the contents from flowing out into the bottle wall, which may penetrate and / or weaken the bottle wall. The coating will be selected according to the expected contents of the container 22, for example, beverages, detergents, medicines, etc. In some examples, an additional drying phase 30 is performed after the coating phase (or before and after the coating phase). In this example, the molded container 22 is then subjected to a curing process 34 that can be configured or optimized according to the coating, for example, drying for 24 hours under ambient conditions or by a flash drying method. In some examples, for example, the additional drying phase 30 occurs after the coating phase, the curing process 34 can be omitted.

[0070] At an appropriate stage of production (e.g., during thermoforming, or before or after coating), a closure or finish forming process may be performed on the molded container 22. For example, Figure 1 As shown, a neck fitting 35 may be attached. In some examples, an exterior coating is applied to the molded container 22, as shown in an additional coating stage 32. In one example, the molded container 22 is immersed in a liquid that coats its exterior surface, as shown in FIG. Figure 1 As shown. One or more additional drying or curing processes may then be performed. For example, the molded container 22 may be allowed to dry in warm air. The molded container 22 may thus be fully formed and ready to receive contents therein.

[0071] Figure 2 A molding system 101 is shown that can be used to thermoform the self-supporting molded container 22 discussed above. The molding system includes a mold 103, a spindle system 105, a pump 107, and a line 109.

[0072] The mold 103 includes a first component and a second component. In other examples, the mold may include more than two components. The two components can be separated to open the mold 103. Each component includes a cavity and a heater 111. When the two components are brought together to close the mold 103, a mold cavity 113 is created in the mold 103 including the cavity of the first component and the second component. The mold includes an opening leading to the mold cavity 113. The heater 111 is operable to heat the two components of the mold and thereby heat the mold cavity 113.

[0073] The spindle system 105 includes a connector 115 , a spindle 117 , an expandable member 119 , a first actuator 121 , a second actuator 123 , a flash memory 125 , and a controller 121 .

[0074] The connector 115 includes an aperture extending through the connector 115 from the top to the bottom of the connector 115. An annular seal is located within the aperture and provides a seal between the connector 115 and the mandrel 117. The seal is a low friction seal and permits movement of the mandrel 117 relative to the connector 115. As described in more detail below, the mandrel 117 moves relative to the connector 115 as the mandrel 117 and expandable member 119 are inserted into and withdrawn from the mold 103.

[0075] The mandrel 117 comprises a cylindrical tube. A plurality of holes 129 are formed along the length of the tube. The holes 129 are located along the lower portion of the tube and extend radially through the tube to allow fluid to flow from the interior of the mandrel 117 to the exterior of the mandrel 117. The mandrel 117 extends through the orifice in the connector 115 and into the expandable member 119 so that the lower portion of the mandrel 117 is located within the expandable member 119. In some examples, the mandrel 117 may be completely located within the expandable member 119 and a different connector 115 may be used. The lower end of the mandrel 117 (i.e., the end of the mandrel 117 located within the expandable member 119) is disconnectably connected to the expandable member (e.g., by a pair of magnets). The mandrel 117 is free to move relative to the connector 115. In particular, the mandrel 117 is free to move up and down within the orifice and is free to rotate within the orifice.

[0076] The expandable member 119 includes an expandable member in the form of an elastomeric bladder. The bladder includes a neck portion and a body portion. The neck portion is sealingly connected to the bottom of the connector 115. The neck portion has a smaller diameter than the body portion. In other examples, the bladder may include a single portion with a constant diameter.

[0077] The first actuator 121 is located on the connector 115 and is coupled to the spindle 117. The operation of the first actuator 121 causes the spindle 117 to move linearly relative to the connector 115 along the longitudinal axis of the spindle 117. In this example, the first actuator 121 includes an electric motor and a transmission mechanism (e.g., a gear, a friction wheel, and / or a rack and pinion) for transmitting the torque generated by the electric motor to the spindle 117. In other examples, the first actuator 121 may include a hydraulic or pneumatic system for moving the spindle 117 relative to the connector 115.

[0078] The second actuator 123 is located at the top end of the spindle 117 and is coupled to the spindle 117. The operation of the second actuator 123 causes the spindle 117 to rotate relative to the connector 115 around the longitudinal axis of the spindle 117. In this example, the second actuator 123 includes an electric motor and a transmission mechanism (e.g., a gear, a friction wheel, and / or a rack and pinion) for transmitting the torque generated by the electric motor to the spindle 117. In other examples, the second actuator 123 may include a hydraulic or pneumatic system for rotating the spindle 117 relative to the connector 115.

[0079] Flash memory 125 stores computer readable instructions that, when in operation, are executed by controller 127 (which may be considered a processor). In other examples, other types of memory may be used.

[0080] Controller 127 controls the operation of actuators 121, 123 and thereby controls the movement of mandrel 117 relative to connector 115. Controller 127 also controls pump 107, heater 111, and a robotic arm (not shown) that moves connector 115 relative to mold 103.

[0081] The pump 107 includes a cylinder that displaces a fluid in a pipeline 109. In some examples, the fluid is one of air, water, or oil. When the pipeline 109 is connected to the top of the mandrel 117, displacing the fluid causes the pump 107 to supply pressurized fluid to the interior of the mandrel 117. The pressurized fluid then flows through the hole 129 in the mandrel 117 and flows into the expandable member 119. Thus, the pump 107 is used to expand the expandable member 119. The pump 107 is also capable of operating in the opposite direction to extract fluid from the expandable member 119 and thereby collapse and contract the expandable member 119.

[0082] Now refer to Figures 3 to 6 The use of the molding system 101 is described. The controller 127 controls the heater 11 to heat the two parts of the mold 103. Figure 3As shown in (a), the two parts of the mold 103 are then closed around the partially formed container 22 so that the partially formed container 22 is located inside the mold cavity 113. The partially formed container 22 has the shape of a bottle and includes a main body and a neck 133. The neck 115 has a smaller diameter than the main body. The main body includes a side 135, which has a cylindrical shape of a base 137 connected to the main body by a corner 139. At this stage, the mandrel system 105 is located outside the mold cavity 113 and the expandable member 119 is connected to the mandrel 117. In addition, the expandable member 119 is in a natural static state. That is, the pump 107 does not apply negative pressure or positive pressure to the state inside the expandable member 119.

[0083] Now turn to Figure 3 (b), the controller 127 controls the first actuator 123 to move the mandrel 117 downward relative to the connector 115. As the mandrel 117 moves downward, the end of the mandrel 117 forces the bottom of the expandable member 119 downward, which increases the length of the expandable member 119. This increase in the length of the expandable member 119 causes a corresponding decrease in the width of the expandable member 119. At the same time, the controller 127 operates the second actuator 123 to rotate the mandrel 117 relative to the connector 115. Since the expandable member 119 is attached to the end of the mandrel 117, the rotation causes the expandable member 119 to twist around the mandrel 117 and further reduce the width of the expandable member 119.

[0084] The controller 127 then controls the actuators 121, 123 to stop the downward movement and rotation of the mandrel 117. At this stage, the width of the expandable member 119 is less than the width of the opening of the mold 103. Thus, the mandrel 117 and the expandable member 119 can pass through the opening of the mold 103 without the expandable member 119 contacting the mold 103 or the partially formed container 22.

[0085] Now turn to Figure 3 (c), the controller 127 then controls the robot arm to move the connector 115 downward and toward the mold 103. As the connector 115 moves downward, the mandrel 117 and the expandable member 119 are inserted through the opening into the mold cavity 113. Due to the previous downward movement of the mandrel 117 relative to the connector 115 (refer to Figure 3 (b)), the length of the mandrel 117 is too long to fit within the mold cavity 113. Therefore, once a predetermined length of the mandrel 117 has been inserted into the mold cavity 113, the controller 127 operates the first actuator 121 to move the mandrel 117 upward relative to the connector 115. The upward movement of the mandrel 117 relative to the connector 115 causes the length of the expandable member 119 to decrease and the width of the expandable member 119 to increase.

[0086] The controller 127 then operates the second actuator 123 to rotate the mandrel 117 relative to the connector 115 to release the twist of the expandable member 119 about the mandrel 117. This then causes the width of the expandable member 119 to increase further.

[0087] Now turn to Figure 3 (d), with the expandable member 119 now positioned within the mold cavity 113, the controller 127 controls the pump 107 to supply pressurized fluid to the mandrel, which flows through the hole 129 in the mandrel 117 and into the expandable member 119 to expand the expandable member 119 from a natural resting state to a partially expanded state in which the pump 107 has applied a positive pressure to the interior of the expandable member. The expansion of the expandable member 119 disconnects the expandable member from the end of the mandrel 117. The controller 127 stops the expansion of the expandable member 119 when the expandable member 119 has expanded to 105% to 125% of its natural resting state. At this stage, there is a gap between the expandable member 119 and the side 135 of the body of the partially formed container 22. The gap is measured along the gap axis and is between 1 and 4 times the thickness of the wall of the expandable member measured along the gap axis.

[0088] Now turn to Figure 4 , with the expandable member 119 now in a partially expanded state, the controller 127 controls the robotic arm to move the connector 115 downward and into contact with the top of the mold 103. As the connector 115 moves downward, the expandable member 119 moves downward and into contact with the base 137 of the partially formed container 22. This movement causes the expandable member 119 to deform against the base 139 of the partially formed container 22, as shown in FIG. Figure 4 The expandable member 119 is deformed toward the periphery of the base 137 of the partially formed container 22 (i.e., toward the corner 139 of the body of the partially formed container 22). Once deformed, the distance 140 between the expandable member 119 and the periphery of the base 139 of the partially formed container 22 is no greater than 50% of the radius of the base 137 of the partially formed container 22.

[0089] Additionally, once deformed, the radius of the corner 141 of the expandable member 119 adjacent to the corner 139 of the partially formed container 22 is no greater than 130% and no less than 70% of the radius of the corner 139 of the body of the partially formed container 22. In other examples, the radius of the corner 141 of the expandable member 119 is no greater than 110% and no less than 90% of the radius of the corner 139 of the body of the partially formed container 22.

[0090] Due to the Poisson effect, the deformation of the expandable member against the base of the partially formed container causes other portions of the expandable member to experience associated deformation. Specifically, the movement of the expandable member 119 into contact with the base 137 of the partially formed container 22 also causes the expandable member 119 to deform into contact with the neck 133 of the partially formed container 22. That is, once deformed, the expandable member 119 will contact the neck 133 of the partially formed container 22.

[0091] After a duration of less than 1 second from the time the expandable member 119 first contacts the base 137 of the partially formed container 22, the partially formed container 22 is subjected to a forming operation ( Figure 6 (a)). The controller 127 controls the pump 107 to supply pressurized fluid to the mandrel 117, and the pressurized fluid flows through the hole 129 in the mandrel 117 and flows into the expandable member 119 to further expand the expandable member 119 from the partially expanded state to the more expanded state, wherein the expandable member 119 contacts other portions of the partially formed container 22 (e.g., the side 135 of the body) and drives the partially formed container 22 against the inner surface of the mold 103. In this example, the partially expanded state is the first configuration, the more expanded state is the second configuration, and the natural rest state is the third configuration. Since the controller 127 has previously controlled the heater 111 to heat the two parts of the mold 103, the partially formed container 22 will be heated. As a result, the partially formed container 22 will be heated and compressed so that the container 143 can be formed from the partially formed container 22.

[0092] Now turn to Figure 6 (b), once the shaping operation is completed, the controller 127 controls the pump 107 to withdraw the pressurized fluid from the expandable member 119, which causes the expandable member 119 to collapse and contract from the more expanded state to the natural resting state. When the expandable member 119 contracts, the expandable member 119 reconnects with the end of the mandrel 117.

[0093] The controller 127 then controls the robot arm to move the connector 115 upward relative to the mold 103 ( Figure 6(c)). At the same time, the controller 127 controls the first actuator 121 to move the mandrel 117 downward relative to the connector 115 at the same rate as the connector 115 moves upward, so that the end of the mandrel 117 remains stationary relative to the mold 103. As a result, the length of the expandable member 119 is increased, which causes the width of the expandable member 119 to decrease. The controller 127 also controls the second actuator 123 to rotate the mandrel 117 relative to the connector, so that the expandable member 119 twists around the mandrel 117 to further reduce the width of the expandable member 119. In the case where the expandable member 119 is elongated and twisted around the mandrel 117, the controller 127 controls the actuators 121, 123 to stop the movement of the mandrel 117 relative to the connector 115.

[0094] Now turn to Figure 6 (d), the controller 127 controls the robot arm to move the connector 115 upward relative to the mold 103 to extract the mandrel 117 and the expandable member 119 from the mold 103 through the opening. Once the mandrel 117 and the expandable member 119 are extracted from the mold 103, the mold 103 is opened by separating the two parts of the mold 103 and the container 143 is removed for further processing. For example, the container 143 can be dried in the drying stage 29, as described above with reference to Figure 1 described.

[0095] With respect to the method of expanding the expandable member 119 to form the container 143 without first deforming the expandable member 119 toward the perimeter of the base 137 of the partially formed container 22, the friction generated at the point where the expandable member 119 initially contacts the partially formed container 22 may inhibit the expandable member 119 from further expanding into the perimeter. This may result in under-compaction of the perimeter, which in turn may result in a weak point in the container 143.

[0096] Alternatively or additionally, such friction may result in uneven stretching of the expandable member 119. For example, portions of the expandable member 119 that are not restrained by friction may overstretch to compensate for portions of the expandable member 119 that are restrained by friction. Such overstretching may damage or fatigue the expandable member 119. Deforming the expandable member 119 toward the periphery before expanding the expandable member 119 to form the container 143 may mitigate these factors. Specifically, the expandable member 119 may be more likely to expand into the periphery of the base 137 of the partially formed container 22 than a method that does not deform the expandable member 119 toward the periphery before expanding the expandable member 119 to form the container 143. This may reduce the occurrence of weak points in the container 143 caused by insufficient compaction of the material from which the container 143 is made. Additionally or alternatively, the expandable member 119 may be more likely to stretch in a uniform manner and thereby reduce the possibility of damage or fatigue due to overstretching. Thus, the life of the expandable member 119 may be improved.

[0097] In the above examples, the third configuration is the natural resting state of expandable member 119. However, in other examples, when in the third configuration, pump 107 applies negative pressure to the interior of expandable member 119, causing expandable member 119 to collapse from its natural resting state. In these other examples, the first configuration is the natural resting state of expandable member 119 or a state in which expandable member 119 has been expanded from its natural resting state.

[0098] In the above example, the forming operation is applied less than 1 second after the expandable member 119 has contacted the base 137 of the partially formed container 22. In other examples, other durations may be used. For example, less than 0.9 seconds, less than 0.75 seconds, or less than 0.5 seconds.

[0099] In the above examples, the ends of the mandrel 117 are disconnectably connected to the expandable member 119. However, in other examples, the ends of the mandrel 117 may be permanently connected to the expandable member 119. In one example, once the expandable member 119 contacts the base 137 of the partially formed container 22, the controller 127 controls the first actuator 121 to move the mandrel 117 upward at the same rate as the connector 115 moves downward, so that the mandrel 117 remains stationary relative to the mold 103. In a second example, the first actuator 121 has an active and a passive mode. In the active mode, the first actuator 121 moves the mandrel 117 relative to the connector 115, and in the passive mode, the first actuator 121 is disengaged or idle, so that the mandrel 117 is free to move relative to the connector 115. The first actuator 121 operates in an active mode to increase and decrease the length of the mandrel 117, and then operates in a passive mode during the movement of the expandable member 119 into contact with the base 137 of the partially formed container 22 and the expansion and contraction of the expandable member 119. In a third example, the mandrel 117 has a first telescopic part and a second telescopic part. The expandable member 119 is connected to the second telescopic part and the second telescopic part moves in and out of the first telescopic part to accommodate the movement and expansion of the expandable member 119. Similarly, the mandrel 117 can be permanently disconnected from the expandable member 119, and the mandrel 117 can be non-rotatable to allow the expandable member 119 to twist around the mandrel 117.

[0100] Example embodiments of the invention have been discussed with reference to the examples illustrated. However, it will be appreciated that changes and modifications may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A method for molding a container, the method comprising: Provide molds; providing a partially formed container in the mold; providing an expandable member in a first configuration within the partially formed container; moving the expandable member in the first configuration into contact with a base of the partially formed container such that the expandable member deforms toward a periphery of the base of the partially formed container; as well as Fluid is injected into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration so as to urge the partially formed container against the inner surface of the mold during the process of forming the container from the partially formed container.

2. A method as claimed in claim 1, wherein the expandable member is moved into contact with the base so that the distance between the expandable member and the periphery of the base of the partially formed container is no greater than 50% of the radius of the base of the partially formed container.

3. The method of claim 1 or claim 2, wherein: the partially formed container comprising a side portion and a corner portion, the corner portion joining a portion of the perimeter of the base of the partially formed container to the side portion of the partially formed container; said corner of said partially formed container having a first radius of curvature; the expandable member including a corner portion that is adjacent to the corner portion of the partially formed container prior to injecting a fluid into the expandable member to further expand the expandable member; and The expandable member is moved into contact with the base so that the corner of the expandable member has a second radius of curvature that is no greater than 130% and no less than 70% of the first radius of curvature.

4. A method as described in any one of claims 1 to 3, wherein before or during the movement of the expandable member into contact with the base of the partially formed container, a gap exists between the expandable member and the side of the partially formed container.

5. A method as claimed in claim 4, wherein the gap is measured along a gap axis and the gap is not less than the thickness of the wall of the expandable member measured along the gap axis.

6. A method as claimed in claim 4 or claim 5, wherein the gap is measured along a gap axis and the gap is no greater than 4 times the thickness of the wall of the expandable member measured along the gap axis.

7. The method according to any one of claims 1 to 6, wherein: The container comprises a neck; and The expandable member is moved into contact with the base of the container such that the expandable member is deformed into contact with the neck of the container.

8. The method according to any one of claims 1 to 7, wherein: The mold includes an opening; and Providing an expandable member in a first configuration within the partially formed container comprises: providing the expandable member in a third configuration outside the mold in which the expandable member is less expanded than when in the first configuration; inserting the expandable member in the third configuration into the mold through the opening; and A fluid is injected into the expandable member to expand the expandable member from the third configuration to the first configuration.

9. A method as claimed in claim 8, wherein the method includes providing a core shaft at least partially located within the expandable member.

10. The method of claim 9, wherein the method comprises at least one of the following: rotating the mandrel relative to the mold to twist the expandable member about the mandrel to reduce a width of the expandable member; and The mandrel is rotated relative to the mold to untwist the expandable member about the mandrel to increase the width of the expandable member.

11. A method as claimed in claim 9 or claim 10, wherein the method includes moving the mandrel to change the width of the expandable member.

12. A method as claimed in any one of claims 1 to 11, wherein the partially formed container is at least partially formed from paper pulp.

13. The method of any one of claims 1 to 12, wherein the method comprises applying heat to the partially formed container during the injection of fluid into the expandable member to further expand the expandable member.

14. The method of claim 13, wherein: The partially formed container is at least partially formed from paper pulp; heating the mold to heat the partially formed container; and The duration between moving the expandable member into contact with the base of the partially formed container and injecting fluid into the expandable member to expand the expandable member from the first configuration to the second configuration is no greater than 1 second.

15. A container obtainable or obtained from a method of manufacture comprising the method of any one of claims 1 to 13.

16. The container of claim 15, wherein the container is a bottle.

17. A molding system comprising: a mold for receiving the partially formed container; an expandable member; a pump fluidly connected to the expandable member; as well as Controller, wherein when the expandable member is in the first configuration and provided within the partially formed container, the controller is configured to: moving the expandable member into contact with a base of the partially formed container such that the expandable member deforms toward a periphery of the base of the partially formed container; as well as The pump is caused to inject fluid into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration so as to drive the partially formed container against the inner surface of the mold during the process of forming a container from the partially formed container.

18. The molding system of claim 17, wherein the controller is configured to: inserting the expandable member into the mold through an opening of the mold in a third configuration in which the expandable member is less expanded than when in the first configuration; and The pump is caused to inject fluid into the expandable member to expand the expandable member from the third configuration to the first configuration.

19. A molding system as described in claim 18, wherein the controller is configured to cause the pump to inject fluid into the expandable member to expand the expandable member from the third configuration to the first configuration so that a gap exists between the expandable member and the side of the partially formed container.

20. The molding system of claim 19, wherein the gap is measured along a gap axis and the gap is not less than a thickness of a wall of the expandable member measured along the gap axis.

21. A molding system as described in claim 19 or claim 20, wherein the gap is measured along a gap axis and the gap is no greater than 4 times the thickness of the wall of the expandable member measured along the gap axis.

22. A molding system as described in any one of claims 17 to 21, wherein the controller is configured to move the expandable member into contact with the base of the partially formed container so that the distance between the expandable member and the periphery of the base of the partially formed container is no greater than 50% of the radius of the base of the partially formed container.

23. The molding system of any one of claims 17 to 22, wherein: the partially formed container comprising a side portion and a corner portion, the corner portion joining a portion of the perimeter of the base of the partially formed container to the side portion of the partially formed container; said corner of said partially formed container having a first radius of curvature; the expandable member including a corner portion, the corner portion being adjacent to the corner portion of the partially formed container before the controller causes the pump to inject fluid into the expandable member to expand the expandable member; and The controller is configured to move the expandable member into contact with the base of the partially formed container so that the corner of the expandable member has a second radius of curvature that is no greater than 130% and no less than 70% of the first radius of curvature.

24. A molding system as claimed in any one of claims 17 to 23, wherein the molding system includes a core shaft that is at least partially located or partially locatable inside the expandable member.

25. The molding system of any one of claims 17 to 23, wherein: The molding system includes a heater; and The controller is configured to cause the heater to apply heat to the partially formed container during injection of fluid into the expandable member to expand the expandable member from the first configuration to the second configuration.

26. A moulding system as claimed in any one of claims 17 to 25, wherein the moulding system is a pulp container moulding system.

27. A non-transitory storage medium storing machine-readable instructions, a molding system comprising a mold and an expandable member in a first configuration within a partially formed container, the machine-readable instructions, when executed by a processor of the molding system, causing the processor to: moving the expandable member into contact with a base of the partially formed container such that the expandable member deforms toward a periphery of the base of the partially formed container; and Fluid is injected into the expandable member to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration so as to drive the partially formed container against the inner surface of the mold during the process of forming a container from the partially formed container.

Images