Method and Mold System

Abstract

A method of forming a container is described. The method includes providing a mold, providing a partially formed container within 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 towards a peripheral portion of the base of the partially formed container, inserting 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 press the partially formed container against an inner surface of the mold through a process of forming the container from the partially formed container.

Description

Technical Field

[0001] The present invention relates to a method of forming a container and a mold system.

Background Art

[0002] It is desirable to reduce the use of consumables, particularly plastics in packaging. Simple shapes such as trays are generally made from paper pulp, but more complex objects such as bottles are more difficult to engineer. For example, it can be difficult to reliably compress paper pulp within a mold forming a bottle. If the compression is insufficient, weak points can occur in the bottle.

Summary of the Invention

[0003] According to a first aspect of the present invention, there is provided a method of forming a container. The method includes providing a mold, providing a partially formed container within 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 towards a periphery of the base of the partially formed container, and inserting 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 press the partially formed container against an inner surface of the mold throughout a process of forming the container from the partially formed container.

[0004] In a method of forming a container by expanding an expandable member without first deforming the expandable member towards a periphery of a base of the partially formed container, friction generated at a point where the expandable member first contacts the partially formed container may prevent the expandable member from further expanding towards the periphery. This can result in insufficient compression of the periphery and the formation of weak points in the container.

[0005] Alternatively, or in addition, this friction can cause non-uniform stretching of the expandable member. For example, portions of the expandable member that are not restrained by the friction may stretch excessively to compensate for portions of the expandable member that are restrained by the friction. This excessive stretching can damage or fatigue the expandable member. These factors can be mitigated by deforming the expandable member towards the periphery before expanding the expandable member to form the container. Specifically, the expandable member may be more likely to expand towards the periphery of the base of the partially formed container than in a method where the expandable member is not deformed towards the periphery before expanding the expandable member to form the container. This can reduce the occurrence of weak points in the container due to insufficient compression of the material from which the container is made. Additionally, or alternatively, the expandable member may be more likely to stretch uniformly, thereby reducing the potential for damage or fatigue due to excessive stretching. Thereby, the lifespan of the expandable member can be extended.

[0006] Optionally, the first configuration is the natural rest state of the expandable member (e.g., a state where no radial inward or outward pressure is applied to the expandable member, and / or a state where no negative or positive pressure is applied inside the expandable member). Alternatively, the first configuration is a state where some positive pressure is applied inside the expandable member to expand the expandable member from its natural rest state.

[0007] Optionally, the container is a bottle.

[0008] Optionally, the expandable member is moved into contact with the base such that the distance between the expandable member and the periphery of the base of the partially formed container is 50% or less of the radius of the base of the partially formed container. Thereby, the portion of the expandable member that expands to the periphery of the base of the partially formed container will be located closer to the periphery than when the distance exceeds 50%. Thereby, the expandable member may be more likely to be expanded by the periphery of the base of the partially formed container, thereby reducing the occurrence of vulnerable locations within the container. Further, when the expandable member expands to the second configuration, the pressure applied to the partially formed container by the expandable member can be more evenly distributed compared to when the distance exceeded 50%. Further, having the distance be 50% or less reduces the strain within the expandable member compared to when the distance exceeds 50%, thereby extending the life of the expandable member.

[0009] Optionally, the partially formed container includes sides and corners that join a portion of the periphery of the base of the partially formed container to the sides of the partially formed container. Optionally, the corners of the partially formed container have a first radius of curvature. Optionally, the expandable member includes corners adjacent to the corners of the partially formed container prior to inserting fluid into the expandable member to further expand the expandable member. Optionally, the expandable member is moved into contact with the base such that the corners of the expandable member have a second radius of curvature that is 130% or less and 70% or more of the first radius of curvature. As a result, prior to expanding the expandable member to form the container, the shape of the expandable member located adjacent to the corners of the partially formed container is substantially the same as the corners of the partially formed container. Thereby, the likelihood of conforming to the shape of the corners of the partially formed container when the expandable member is expanded can be improved compared to a second radius that deviates from these values. This improved conformity may improve the compression of the partially formed container at the corners, thereby reducing the occurrence of vulnerable locations.

[0010] Optionally, the expandable member is moved to contact the base such that a second radius of curvature is 110% or less and 90% or more 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 moving the expandable member to contact the base of the partially formed container. Thereby, during the movement of the expandable member before expanding the expandable member to form the container, the possibility that the expandable member rubs against and damages the side of the partially formed container can be reduced compared to a method where there is no gap between the expandable member and the side of the partially formed container.

[0012] Optionally, the gap is measured along a gap axis and the gap is at least as large as the wall thickness of the expandable member measured along the gap axis. Thereby, the possibility of rubbing can be reduced compared to a gap smaller than the measured wall thickness of the expandable member.

[0013] Optionally, the gap is measured along a gap axis and the gap is at most four times the wall thickness of the expandable member measured along the gap axis. As a result, a wider expandable member may be used compared to a gap greater than four times the wall thickness of the expandable member, which can increase the possibility that the expandable member can expand around the periphery of the base of the partially formed container. Specifically, to achieve a gap greater than four times the wall thickness of the expandable member, it may be necessary to use a thinner expandable member.

[0014] Optionally, the container includes a neck, and the expandable member is moved to contact the base of the container, such that the expandable member deforms to contact the neck of the container. As a result, a high friction region may be created between the neck and the expandable member, thereby enabling the expandable member to be fixed to the container. This can reduce the likelihood that the expandable member moves away from the base of the container during subsequent expansion of the expandable member as compared to a process where the neck is not contacted by the expandable member. This can improve the compression of the base of the container, thereby potentially reducing the likelihood of creating a weak point in the container.

[0015] Optionally, the mold includes an opening. Optionally, providing the expandable member within the partially formed container in a first configuration comprises providing the expandable member external to the mold in a third configuration in which the expandable member is less expanded than when in the first configuration, inserting the expandable member in the third configuration through the opening into the mold, and inserting fluid into the expandable member to expand the expandable member from the third configuration to the first configuration. Inserting the expandable member in the (less expanded) third configuration can enable insertion of a wider expandable member into the partially formed container without damaging the expandable member or the partially formed container during insertion as compared to inserting the expandable member in the first configuration. Widening the expandable member can increase the likelihood that the expandable member expands towards the periphery, thereby potentially reducing the occurrence of weak points in the container.

[0016] Subsequently, expanding the expandable member from the third configuration to the first configuration can increase the range in which the expandable member can deform towards 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 before contacting the base of the container, the collapsed expandable member may be less likely to deform towards the periphery of the base of the container.

[0017] Optionally, the method includes removing the expandable member from the mold through an opening after the process of forming the container from the partially formed container. Thereby, the expandable member can be reused to form a plurality of containers, and the cost of the molding process adopting this method can be reduced.

[0018] Optionally, when in the third configuration, a negative pressure is applied inside the expandable member, causing the expandable member to collapse.

[0019] Optionally, the method includes providing a mandrel that is at least partially disposed inside the expandable member. By providing the mandrel, structural support can be provided to the expandable member, which can help properly position the expandable member before expanding the expandable member to form the container. Thereby, when expanding the expandable member to form the container, the expandable member may be more likely to expand around the periphery of the base of the partially formed container compared to a method where no mandrel is provided.

[0020] Optionally, the mandrel includes one or more holes through which fluid can flow from the inside of the mandrel to the outside of the mandrel to expand the expandable member.

[0021] Optionally, the method includes rotating the mandrel relative to the mold to twist the expandable member around the mandrel to narrow the width of the expandable member, and rotating the mandrel relative to the mold to untwist the expandable member from around the mandrel to widen the width of the expandable member, at least one of which. As a result, the width of the expandable member can vary. Thereby, the width of the expandable member can be reduced to facilitate the expandable member passing through the opening, and then the expandable member can be expanded to form a container. Advantageously, this may allow the use of a wider expandable member than would otherwise be possible without twisting the expandable member. Widening the expandable member may increase the likelihood that the expandable member expands to the peripheral portion, thereby reducing the occurrence of vulnerable locations in the container.

[0022] Optionally, the expandable member is attached to the mandrel, and 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. Thereby, the width of the expandable member can be reduced to facilitate the expandable member passing through the opening, and then the expandable member can be expanded to form a container. Advantageously, this may allow the use of a wider expandable member than would otherwise be possible without changing the width of the expandable member. Widening the expandable member may increase the likelihood that the expandable member expands to the peripheral portion, thereby reducing the occurrence of vulnerable locations in the container.

[0024] Optionally, the expandable member is attached to the mandrel, and the method includes providing 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.

[0025] Optionally, the partially formed container is at least partially formed of paper pulp. The choice of paper is more environmentally friendly than plastic. However, when formed from paper pulp, the container is particularly prone to weak spots due to insufficient compression. Before expanding the expandable member to form the container, by deforming the expandable member towards the periphery of the base of the partially formed container, before expanding the expandable member to form the container, there may be a higher likelihood that the expandable member will expand towards the periphery than in a method where the expandable member is not deformed towards the periphery. This can reduce the likelihood of weak spots forming in the container due to insufficient compression occurring.

[0026] Optionally, the method includes applying heat to the partially formed container while inserting fluid into the expandable member to further expand the expandable member. This applies a thermoforming operation to the partially formed container. Thermoforming can improve not only the mechanical properties such as the rigidity of the container but also the surface finish of the container.

[0027] Optionally, the partially formed container is at least partially formed of paper pulp, the mold is heated to heat the partially formed container, and the expandable member is moved to contact the base of the partially formed container, and fluid is inserted into the expandable member to expand the expandable member from a first configuration to a second configuration. The time between is 1 second or less. When the expandable member contacts the base of the partially formed container, a part of the paper pulp at the base can be pushed into the mold by the expandable member. By heating the mold, the water in the paper pulp at the base can turn into steam. The steam can apply pressure to the outside of the base of the container. When this flash occurs and the expandable member is only in the first configuration, the expandable member may not be able to apply sufficient pressure to the inside of the base of the container to counteract the pressure applied by the steam. This can damage the paper pulp and result in vulnerable spots in the container. By expanding the expandable member in less than 1 second after contacting the base, the expandable member may be expanded in time to apply sufficient pressure to counteract the pressure applied by the steam, thereby reducing the possibility of this damage compared to when the duration between operations is longer.

[0028] Optionally, the duration is 0.9 seconds or less. Optionally, the duration is 0.75 seconds or less. Optionally, the duration is 0.5 seconds or less.

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

[0030] Optionally, the manufacturing method includes at least one additional process. Optionally, the at least one additional process includes coating and drying the container to produce a coated container. Optionally, the at least one additional process includes 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, there is provided a mold system including a mold for receiving a partially formed container, an expandable member, a pump fluidly connected to the expandable member, and a controller. When the expandable member is in a first configuration and provided within the partially formed container, the controller is configured to move the expandable member to contact the base of the partially formed container such that the expandable member deforms towards the periphery of the base of the partially formed container, and to insert fluid into the expandable member via the pump to expand the expandable member from the first configuration to a second configuration that is more expanded than the first configuration so as to press the partially formed container against the inner surface of the mold throughout 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 where no radial inwards or outwards pressure is applied to the expandable member, and / or a state where no negative or positive pressure is applied inside the expandable member). Alternatively, the first configuration is a state where some positive pressure is applied inside the expandable member to expand the expandable member from its natural resting state.

[0035] Optionally, the controller inserts the expandable member in a third configuration, in which the expandable member is less expanded than when in the first configuration and is inserted into the mold through the opening of the mold, and causes the pump to insert 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 configuration (less expanded) may allow a wider expandable member to be inserted into the partially formed container without damaging the expandable member or the container during insertion, compared to inserting the expandable member in the second configuration. By making the expandable member wider, there is a greater likelihood that the expandable member will expand into the peripheral portion, thereby reducing the occurrence of vulnerable areas in the container.

[0036] Optionally, when in the third configuration, a negative pressure is applied inside the expandable member to collapse the expandable member.

[0037] Optionally, the controller is configured such that the pump inserts 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 the side of the partially formed container.

[0038] Optionally, the gap is measured along a gap axis and is greater than or equal to the thickness of the wall of the expandable member measured along the gap axis. Optionally, the gap is measured along a gap axis and is less than or equal to four 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 the distance between the expandable member and the periphery of the base of the partially formed container is 50% or less of the radius of the base of the partially formed container.

[0040] Optionally, the partially formed container includes sides and corners that join a portion of the perimeter of the base of the partially formed container to the sides of the partially formed container. Optionally, the corners of the partially formed container have a first radius of curvature. Optionally, the expandable member includes corners adjacent to the corners of the partially formed container before the controller causes the pump to insert 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 such that the corners of the expandable member have a second radius of curvature that is no more than 130% 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 more than 110% and no less than 90% of the first radius of curvature.

[0042] Optionally, the mold system includes a mandrel that is at least partially disposed within or is partially disposable within the expandable member.

[0043] Optionally, the mandrel is rotatable relative to the expandable member and the expandable member can be screwed around the mandrel.

[0044] Optionally, the mold 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 is movable to vary the width of the expandable member.

[0046] Optionally, the mold 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 mold system includes a heater, and the controller is configured such that while fluid is inserted into the expandable member to expand the expandable member from a first configuration to a second configuration, the heater applies heat to a partially formed container.

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

[0049] According to a fourth aspect of the present invention, a non - transitory storage medium storing machine - readable instructions, the machine - readable instructions, when executed by a processor of a mold system including a mold and an expandable member disposed in a first configuration within a partially formed container, cause the processor to move the expandable member so as to contact the base of the partially formed container, such that the expandable member deforms towards the periphery of the base of the partially formed container, and to insert 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 press the partially formed container against the inner surface of the mold throughout the process of forming the container from the partially formed container.

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

[0051] Optional features of aspects of the present invention can, where appropriate, be applied mutatis mutandis to other aspects of the present invention.

[0052] Hereinafter, embodiments of the present invention will be described by way of example with reference to the accompanying drawings.

Brief Description of the Drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0054] The following description presents exemplary embodiments and, together with the drawings, serves to explain the principles of the embodiments of the present invention.

[0055] Figure 1 shows a process for making bottles from paper pulp (i.e., which can form the basis of an exemplary fiber suspension). This process is merely exemplary and is provided to give context to the examples of the present invention. Broadly speaking, the exemplary process includes providing a fiber suspension, introducing the fiber suspension into the mold cavity of a porous first mold, using the porous first mold to drain liquid (such as water) from the fiber suspension to create a wet precursor or embryo (which may itself be considered a formed container), further shaping the wet precursor with a mold to create a further shaped container, further coating the further shaped container to create a coated shaped container, drying the coated shaped container to create a dried container, and applying a closure to the dried container. As will be apparent at least from the following description, modifications to the exemplary process can be made to provide variations that can embody other examples of the present invention.

[0056] In this example, providing a fiber suspension includes preparing the fiber suspension from its components. More specifically, the preparation includes providing pulp fibers, such as paper pulp fibers, and mixing the pulp fibers with a liquid to provide a hydrated pulp fiber. 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 a hydrated pulp fiber having a solid fiber content of 1 wt% to 5 wt% (based on the dry mass of the fibers). In the example, the one or more additives include sizing agents such as alkyl ketene dimer (AKD). The hydrated pulp fiber typically includes AKD in an amount of 0.4 wt% based on the total dry mass of the solid fibers in the hydrated pulp fiber. In some examples, the one or more additives are present in the liquid at the time the pulp fibers are mixed with the liquid. In some examples, the one or more additives are included in the hydrated pulp fiber after the pulp fibers are mixed 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 fiber). The hydrated pulp fibers pass between the plates of a valley beater 11 or a refiner that are moving relative to each other. This fibrillates some or all of the fibers, meaning that the cell walls of those fibers are partially delaminated and thus their wet surfaces include protrusions or fibrillations. These fibrillations help increase the strength of the bonds between the fibers in the dried final product. In other examples, the valley beater 11 or the refiner may be omitted.

[0057] The resulting processed pulp is stored in tank 12 in a relatively concentrated form (e.g., a solid fiber content of 1 wt% to 5 wt%) to reduce the required storage space. At an appropriate time, the processed pulp is transferred to mixing station 13, where the processed pulp is diluted with additional water and optionally mixed with one or more additives (in addition to or instead of one or more additives provided to the aqueous pulp fibers) to provide a fiber suspension ready for forming. In this example, the solid fibers account for 0.7 wt% of the resulting fiber suspension (by 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% (by dry weight of the fibers) of the fiber suspension. In some examples, the one or more additives mixed with the processed pulp and water include a dehydrating agent, such as modified and / or unmodified polyethyleneimine (PEI), for example, modified PEI sold under the trademark Polymin® SK. In some examples, the 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 and water are mixed and then the one or more additives are subsequently mixed with the processed pulp and water. The fiber suspension typically contains Polymin® SK in an amount of 0.3 wt% relative to the total dry mass of the solid fibers. Mixing of the fiber suspension at mixing station 13 helps to homogenize the fiber suspension. In other examples, the processed pulp or fiber suspension may be provided in other ways, such as being supplied pre-made.

[0058] In this example, the porous first mold 15 includes two half - molds, which in this case are movable towards and away from each other using hydraulic rams. 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. When the half - molds contact each other, their respective mold profiles cooperate to define a mold cavity in which a wet precursor or a formed container is formed. Each half - mold can itself define a smaller molding cavity, and when cooperating with the second half - mold, the smaller molding cavities can combine to provide the cavity of the entire mold. The two half - molds may themselves be regarded as "split parts" or "molds", and the overall porous first mold 15 may be regarded as a "split mold" or in this case also a "mold". In other examples, the porous first mold 15 may include more than two split parts, such as three, four, or six split parts that cooperate to define a molding cavity.

[0059] In FIG. 1, unlike the molding process of dipping the mold into a slurry, the fiber suspension (also known as a slurry) is filled into the porous mold 15 from above. The fiber suspension is drawn into the porous mold 15 via line 16 under vacuum, and the excess suspension is drawn into tank 17 via line 18 through the porous mold 15 under vacuum. 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. When the required amount (e.g., a predetermined volume such as 10 liters, or a predetermined mass such as 10 kilograms) of liquid has been collected in tank 17, the suction of the suspension through the porous mold 15 is stopped and the porous mold 15 is opened to the ambient air. In this example, the suspension drawn in with the fiber suspension via line 16 is water, or mainly water (additives may also be present). The liquid drawn into tank 17 via line 18 under vacuum is substantially fiber - free since the fibers remain on the walls of the porous mold 15 to form the embryo of the formed container.

[0060] In one form, to further remove the suspension (e.g., water) from the embryo and form or integrate the three-dimensional shape of the container, an impermeable expansion element 19, e.g., a collapsible bladder, is inserted into the porous mold 15 and expanded to function as the internal high-pressure core structure of the porous mold 15. This process enhances the processability of the wet embryo, moving water from between the fibers, thereby improving the efficiency of the subsequent drying process. The expansion element 19 is actuated and adjusted using a hydraulic pump 20. The pump 20 has a cylinder that moves the fluid in line 21 into the expansion element 19 to expand the expansion element 19 radially and match the mold cavity. The fluid in line 21 is preferably incompressible, such as water. Also, water has the advantage that a leak or rupture of the bladder 19 does not introduce new substances into the system (since the suspension is already water or mainly water).

[0061] Demolding is performed when the porous mold 15 opens to remove the self-supporting formed container 22. It is preferably followed by mold cleaning 23 to remove small fibers and maintain the porosity of the porous mold 15. In this example, while the mold 15 is open, a high-pressure jet fired radially is inserted into the mold cavity. Thereby, fibers are removed from the walls of the mold cavity. Alternatively or additionally, water from the tank 17 is pressurized through the back of the porous mold 15 to remove the trapped fibers. The water is discharged for recirculation to the upstream part of the system. Note that cleaning is important to condition the porous mold 15 for reuse. The porous mold 15 may appear clean after removing the container, but its performance may be impaired if not cleaned.

[0062] 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, with an aluminum mold 25, for thermoforming the desired neck and for surface finishing including optionally embossing and / or debossing 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 inflated via line 27 by a pump 28 to supply a pressurized fluid, such as air, water, or oil. Optionally, during 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 considerably more rigid and the sidewalls are more compressed compared to the state at demolding from the porous mold 15.

[0063] 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, forming with the mold 25 requires some water content to assist in bonding during the compression process. FIG. 1 shows a further drying stage 30 after the drying stage 29, which can utilize hot air circulated, for example, within a "hot box" over the formed container 22. In some examples, microwave or other drying processes may be performed at multiple stages of the overall manufacturing process.

[0064] The formed container 22 is then subjected to a coating stage, during which, in this example, a spray lance 31 is inserted into the formed container 22 to apply one or more surface coatings to the inner wall of the formed container 22. In another example, the formed container 22 is filled instead with a liquid that coats the inner wall of the formed container 22. In practice, such coatings provide a protective layer to prevent the release of contents that may penetrate the bottle wall and / or weaken the bottle wall. The coating is selected according to the intended contents of the container 22, such as beverages, detergents, pharmaceuticals, etc. In some examples, an additional drying stage 30 is performed after (or both before and after) the coating stage. In this example, the formed container 22 is then subjected to a curing process 34, which can be configured or optimized according to the coating, for example, dried for 24 hours under ambient conditions or dried by an air flow drying method. In some examples, for example, if an additional drying stage 30 is performed after the coating stage, the curing process 34 may be omitted.

[0065] A process for forming a closure or mouth may be performed on the formed container 22 at an appropriate production stage (e.g., during thermoforming, or before or after coating). For example, as shown in FIG. 1, a neck filler 35 may be attached. In some examples, an external coating is applied to the formed container 22 as shown in an additional coating stage 32. In one example, the formed container 22 is immersed in a liquid that coats its outer 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 is fully formed and ready to receive contents therein.

[0066] FIG. 2 shows a mold system 101 that can be used to thermoform the self-supporting formed container 22 described above. The mold system includes a mold 103, a mandrel system 105, a pump 107, and a line 109.

[0067] The mold 103 includes a first part and a second part. In other examples, the mold may include three or more parts. These two parts are separable to open the mold 103. Each part includes a cavity and a heater 111. When the two parts are joined to close the mold 103, a mold cavity 113 including the cavities of the first part and the second part is created within the mold 103. The mold includes an opening to the mold cavity 113. The heater 111 is operable to heat the two parts of the mold and thereby heat the mold cavity 113.

[0068] The mandrel system 105 includes a connector 115, a mandrel 117, an expandable member 119, a first actuator 121, a second actuator 123, a flash memory 125, and a controller 127.

[0069] The connector 115 includes a bore that extends through the connector 115 from the top to the bottom of the connector 115. An annular seal is installed within the bore to provide a seal between the connector 115 and the mandrel 117. The seal is a low-friction seal that allows movement of the mandrel 117 relative to the connector 115. As will be described in more detail below, the mandrel 117 moves relative to the connector 115 when the mandrel 117 and the expandable member 119 are inserted and when withdrawn from the mold 103.

[0070] The mandrel 117 includes 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 inside of the mandrel 117 to the outside of the mandrel 117. The mandrel 117 extends into the expandable member 119 through the bore of the connector 115 such that the lower portion of the mandrel 117 is disposed within the expandable member 119. In some embodiments, the mandrel 117 may be fully disposed within the expandable member 119 and different connectors 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 removably connected (e.g., by a pair of magnets) to the expandable member. The mandrel 117 can move freely with respect to the connector 115. Specifically, the mandrel 117 can move freely up and down within the bore and can also rotate within the bore.

[0071] The expandable member 119 includes an inflatable 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 of a constant diameter.

[0072] The first actuator 121 is disposed on the connector 115 and coupled to the mandrel 117. By the operation of the first actuator 121, the mandrel 117 moves linearly with respect to the connector 115 along the longitudinal axis of the mandrel 117. In this example, the first actuator 121 includes an electric motor and a transmission (e.g., gears, friction wheels, and / or a rack and pinion) for transmitting the torque generated by the electric motor to the mandrel 117. In other examples, the first actuator 121 may include a hydraulic or pneumatic system for moving the mandrel 117 with respect to the connector 115.

[0073] The second actuator 123 is located at the upper end of the mandrel 117 and is coupled to the mandrel 117. By the operation of the second actuator 123, the mandrel 117 rotates about the longitudinal axis of the mandrel 117 with respect to the connector 115. In this example, the second actuator 123 includes an electric motor and a transmission (e.g., gears, friction wheels, and / or a rack and pinion) for transmitting the torque generated by the electric motor to the mandrel 117. In other examples, the second actuator 123 may include a hydraulic or pneumatic system for rotating the mandrel 117 with respect to the connector 115.

[0074] The flash memory 125 stores computer-readable instructions that are executed during operation by a controller 127 (which can be regarded as a processor). In another example, other types of memory may be used.

[0075] The controller 127 controls the operation of the actuators 121, 123, thereby controlling the movement of the mandrel 117 with respect to the connector 115. The controller 127 also controls the pump 107, the heater 111, and a robotic arm (not shown) (the robotic arm moves the connector 115 relative to the mold 103).

[0076] The pump 107 includes a cylinder that displaces the fluid in the line 109. In some examples, the fluid is one of air, water, or oil. Since the line 109 is connected to the upper part of the mandrel 117, displacing the fluid causes the pump 107 to supply pressurized fluid into the interior of the mandrel 117. The pressurized fluid then flows into the expandable member 119 through the holes 129 of the mandrel 117. Thereby, the pump 107 is used to expand the expandable member 119. The pump 107 can also operate in the opposite direction to draw fluid from the expandable member 119, thereby collapsing and contracting the expandable member 119.

[0077] Next, the use of the mold system 101 will be described with reference to FIGS. 3 to 6. The controller 127 controls the heater 111 to heat the two parts of the mold 103. As shown in FIG. 3(a), next, the two parts of the mold 103 are closed around the partially formed container 22, and thus the partially formed container 22 is disposed inside the mold cavity 113. The partially formed container 22 has the shape of a bottle and includes a body and a neck 133. The neck 133 has a smaller diameter than the body. The body includes a cylindrical side portion 135 joined to the base 137 of the 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. Further, the expandable member 119 is in a natural rest state. That is, neither negative pressure nor positive pressure is applied inside the expandable member 119 by the pump 107.

[0078] Referring now to FIG. 3(b), the controller 127 controls the first actuator 121 to move the mandrel 117 downward relative to the connector 115. As the mandrel 117 moves downward, the end of the mandrel 117 pushes the bottom of the expandable member 119 downward, thereby increasing the length of the expandable member 119. As the length of the expandable member 119 increases in this way, the width of the expandable member 119 correspondingly decreases. 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, further reducing the width of the expandable member 119.

[0079] Next, the controller 127 controls the actuators 121 and 123 to stop the downward movement and rotation of the mandrel 117. At this stage, the width of the expandable member 119 is smaller than the width of the opening of the mold 103. Thereby, 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.

[0080] Referring now to FIG. 3(c), next, the controller 127 controls the robotic arm to move the connector 115 downward toward the mold 103. As the connector 115 descends, 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 (described with reference to FIG. 3(b)), the length of the mandrel 117 is too long to fit within the mold cavity 113. Thus, when a predetermined length of the mandrel 117 is 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.

[0081] Next, the controller 127 operates the second actuator 123 to rotate the mandrel 117 relative to the connector 115 to unwind the expandable member 119 around the mandrel 117. Thereby, the width of the expandable member 119 further increases.

[0082] Referring now to Fig. 3(d), with the expandable member 119 disposed within the mold cavity 113 at this time, the controller 127 controls the pump 107 to supply pressurized fluid to the mandrel. This pressurized fluid flows into the expandable member 119 through the holes 129 in the mandrel 117, expanding the expandable member 119 from its natural rest state to a partially expanded state in which some positive pressure is applied inside the expandable member by the pump 107. As the expandable member 119 expands, it moves away 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% - 125% of its natural rest state. At this stage, there is a gap between the expandable member 119 and the side portion 135 of the body of the partially formed container 22. The gap is measured along the gap axis and is 1 - 4 times the thickness of the wall of the expandable member measured along the gap axis.

[0083] Referring now to Fig. 4, with the expandable member 119 in a partially expanded state at this time, the controller 127 controls the robotic arm to move the connector 115 downward and bring it into contact with the upper part of the mold 103. As the connector 115 descends, the expandable member 119 moves downward and comes into contact with the base 137 of the partially formed container 22. Due to this movement, the expandable member 119 is deformed with respect to the base 137 of the partially formed container 22 as shown by the dotted line in Fig. 4. The expandable member 119 deforms towards the peripheral portion of the base 137 of the partially formed container 22 (i.e., towards the corner 139 of the body of the partially formed container 22). At the time of deformation, the distance 140 between the expandable member 119 and the peripheral portion of the base 137 of the partially formed container 22 is 50% or less of the radius of the base 137 of the partially formed container 22.

[0084] Further, at the time of deformation, the radius of the corner 141 of the expandable member 119 adjacent to the corner 139 of the partially formed container 22 is 130% or less and 70% or more of the radius of the corner 139 of the body of the partially formed container 22. In other embodiments, the radius of the corner 141 of the expandable member 119 is 110% or less and 90% or more of the radius of the corner 139 of the body of the partially formed container 22.

[0085] Due to the Poisson effect, as the expandable member deforms with respect to the base of the partially formed container, other parts of the expandable member undergo related deformations. Specifically, when the expandable member 119 moves to contact the base 137 of the partially formed container 22, the expandable member 119 also deforms and contacts the neck 133 of the partially formed container 22. That is, when the expandable member 119 deforms, the expandable member 119 contacts the neck 133 of the partially formed container 22.

[0086] After a duration of less than 1 second since the expandable member 119 first contacts the base 137 of the partially formed container 22, a forming operation is performed on the partially formed container 22 (FIG. 6(a)). The controller 127 controls the pump 107 to supply pressurized fluid to the mandrel 117. This pressurized fluid flows into the expandable member 119 through the holes 129 of the mandrel 117, and expands the expandable member 119 from a partially expanded state to a more expanded state where the expandable member 119 contacts other parts of the partially formed container 22 (e.g., the side portion 135 of the body) and presses the partially formed container 22 against the inner surface of the mold 103. In this embodiment, 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 pre-controls the heater 111 to heat the two parts of the mold 103, the partially formed container 22 is heated. As a result, the partially formed container 22 is heated and compressed, and the container 143 is formed from the partially formed container 22.

[0087] Referring now to FIG. 6(b), at the time when the molding operation is completed, the controller 127 controls the pump 107 to draw the pressurized fluid from the expandable member 119, whereby the expandable member 119 collapses from the more expanded state and contracts to the natural rest state. When the expandable member 119 contracts, the expandable member 119 reconnects with the end of the mandrel 117.

[0088] Next, the controller 127 controls the robotic arm to move the connector 115 upward with respect to the mold 103 (FIG. 6(c)). At the same time, the controller 127 controls the first actuator 121 to move the mandrel 117 downward with respect to the connector 115 at the same speed as the connector 115 moves upward so that the end of the mandrel 117 remains stationary with respect to the mold 103. Thereby, the length of the expandable member 119 increases, and as a result, the width of the expandable member 119 decreases. The controller 127 also controls the second actuator 123 to rotate the mandrel 117 with respect to the connector so that the expandable member 119 is twisted around the mandrel 117 to further reduce the width of the expandable member 119. With the expandable member 119 being stretched and twisted around the mandrel 117, the controller 127 controls the actuators 121, 123 to stop the movement of the mandrel 117 with respect to the connector 115.

[0089] Referring now to FIG. 6(d), the controller 127 controls the robotic arm to move the connector 115 upward with respect to the mold 103 and pull out the mandrel 117 and the expandable member 119 from the mold 103 through the opening. When the mandrel 117 and the expandable member 119 are pulled out from the mold 103, the mold 103 is opened by separating the two parts of the mold 103, and the container 143 is taken out for further processing. For example, the container 143 can be dried in the drying stage 29 as described above with reference to FIG. 1.

[0090] In a method of forming the container 143 by expanding the expandable member 119 without first deforming the expandable member towards the periphery of the base 137 of the partially formed container 22, the expandable member 119 may be prevented from further expanding towards the periphery due to the friction generated at the point where the expandable member 119 first contacts the partially formed container 22. As a result, the compression of the periphery may be insufficient, and vulnerable portions may occur in the container 143.

[0091] Alternatively, or additionally, this friction may cause non-uniform stretching of the expandable member 119. For example, the portion of the expandable member 119 not restrained by the friction may stretch excessively to compensate for the portion of the expandable member 119 restrained by the friction. This excessive stretching can damage or fatigue the expandable member 119. By deforming the expandable member 119 towards the periphery before expanding the expandable member 119 to form the container 143, these factors can be reduced. Specifically, the expandable member 119 may be more likely to expand towards the periphery of the base 137 of the partially formed container 22 than in a method where the expandable member 119 is not deformed towards the periphery before expanding the expandable member 119 to form the container 143. This can reduce the occurrence of vulnerable portions of the container 143 due to insufficient compression of the material from which the container 143 is made. Additionally, or alternatively, the expandable member 119 may be more likely to stretch uniformly, thereby reducing the possibility of damage or fatigue due to excessive stretching. Thereby, the lifespan of the expandable member 119 can be extended.

[0092] In the above embodiment, the third configuration is the natural rest state of the expandable member 119. However, in other embodiments, when in the third configuration, the pump 107 applies a negative pressure inside the expandable member 119 such that the expandable member 119 collapses from its natural rest state. In these other embodiments, the first configuration is the natural rest state of the expandable member 119, or a state where the expandable member 119 has expanded from its natural rest state.

[0093] In the above embodiment, the forming operation is applied in less than 1 second after the expandable member 119 contacts the base 137 of the partially formed container 22. In other embodiments, other periods may be used, for example, less than 0.9 second, less than 0.75 second, or less than 0.5 second.

[0094] In the above embodiment, the end of the mandrel 117 is separably connected to the expandable member 119. However, in other embodiments, the end of the mandrel 117 may be permanently connected to the expandable member 119. In one embodiment, when 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 speed as the connector 115 moves downward, so that the mandrel 117 remains stationary with respect to the mold 103. In a second embodiment, the first actuator 121 has an active mode 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 idles, and the mandrel 117 can move freely relative to the connector 115. The first actuator 121 operates in the active mode to increase and decrease the length of the mandrel 117, and then moves until the expandable member 119 contacts the base 137 of the partially formed container 22, and operates in the passive mode while the expandable member 119 expands and contracts. In a third embodiment, the mandrel 117 has a first telescopic portion and a second telescopic portion. The expandable member 119 is connected to the second telescopic portion, and the second telescopic portion moves in and out relative to the first telescopic portion to correspond to the movement and expansion of the expandable member 119. Similarly, the mandrel 117 may be permanently separated from the expandable member 119, and the mandrel 117 may not rotate so as to twist the expandable member 119 around the mandrel 117.

[0095] Exemplary embodiments of the present invention have been described with reference to the illustrated examples. However, it will be understood that variations and modifications can be made without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A method for forming a container, To provide a mold, To provide a partially formed container within the mold, To provide an expandable member in the partially formed container in the first configuration, The expandable member is moved in the first configuration so as to contact the base of the partially formed container, such that the expandable member deforms toward the peripheral portion of the base of the partially formed container. A method comprising: inserting a fluid into the expandable member to expand the expandable member from a first configuration to a second configuration which is expanded beyond the first configuration, so as to push the partially formed container against the inner surface of the mold through a process of forming the container from the partially formed container.

2. The method according to claim 1, wherein the expandable member is moved to contact the base such that the distance between the expandable member and the peripheral portion of the base of the partially formed container is 50% or less of the radius of the base of the partially formed container.

3. The partially formed container includes a part of the peripheral portion of the base of the partially formed container, and the side portion and corners that are joined to the side portion of the partially formed container. The corner of the partially formed container has a first radius of curvature, The expandable member includes a corner adjacent to the corner of the partially formed container before fluid is injected into the expandable member in order to further expand the expandable member, The method according to claim 1 or 2, wherein the expandable member is moved to contact the base such that the corners of the expandable member have a second radius of curvature which is 130% or less and 70% or more of the first radius of curvature.

4. The method according to claim 1 or 2, wherein 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 to contact the base of the partially formed container.

5. The method according to claim 4, wherein the gap is measured along the gap axis, and the gap is greater than or equal to the thickness of the wall of the expandable member measured along the gap axis.

6. The method according to claim 4, wherein optionally, the gap is measured along the gap axis, and the gap is no more than four times the wall thickness of the expandable member measured along the gap axis.

7. The container includes a neck portion, The method according to claim 1 or 2, wherein the expandable member is moved to contact the base of the container, and as a result, the expandable member deforms to contact the neck of the container.

8. The mold includes an opening, and an expandable member is provided in the partially formed container in the first configuration. The expandable member is provided outside the mold in a third configuration in which it does not expand more than when it is in the first configuration. Inserting the expandable member in the third configuration into the mold through the opening, The method according to claim 1 or 2, comprising inserting a fluid into the expandable member in order to expand the expandable member from the third configuration to the first configuration.

9. The method according to claim 8, comprising providing a mandrel that is at least partially disposed inside the expandable member.

10. The method according to claim 9, comprising moving the mandrel to change the width of the expandable member.

11. The method according to claim 1 or 2, wherein the partially formed container is at least partially made of paper pulp.

12. The method according to claim 1 or 2, comprising applying heat to the partially formed container while a fluid is being inserted into the expandable member in order to further expand the expandable member.

13. The partially formed container is made at least partially from paper pulp, The mold is heated to heat the partially formed container, The method according to claim 12, wherein the time between moving the expandable member so that it contacts the base of the partially formed container and inserting fluid into the expandable member to expand the expandable member from the first configuration to the second configuration is 1 second or less.

14. A container that can be obtained or is obtainable from a manufacturing method comprising the method according to claim 1 or 2.

15. The container according to claim 14, which is a bottle.

16. A mold for receiving a partially formed container, Expandable member, A pump fluidly connected to the expandable member, A mold system including a controller, If the expandable member is in the first configuration and provided within the partially formed container, the controller is: The expandable member is moved so as to contact the base of the partially formed container, such that the expandable member deforms toward the peripheral portion of the base of the partially formed container. A mold system configured to inject fluid into the expandable member by pump, so as to push the partially formed container against the inner surface of the mold through a process of forming the container from the partially formed container, and to expand the expandable member from a first configuration to a second configuration which is expanded beyond the first configuration.

17. The aforementioned controller, The expandable member is inserted in a third configuration, wherein in the third configuration, the expandable member expands less than in the first configuration and is inserted into the mold through the opening of the mold, and the insertion is... The mold system according to claim 16, wherein the pump is configured to insert fluid into the expandable member and expand the expandable member from the third configuration to the first configuration.

18. Includes heater, The mold system according to claim 16 or 17, wherein the controller is configured to insert fluid into the expandable member to expand the expandable member from the first configuration to the second configuration, and the heater is configured to heat the partially formed container.

19. The mold system according to claim 16 or 17, which is a paper pulp container mold system.

20. A non-temporary storage medium for storing machine-readable instructions, wherein the machine-readable instructions are executed by a processor of a mold system including a mold and expandable members arranged in a first configuration within a partially formed container, and the processor is instructed to: The expandable member is moved so as to contact the base of the partially formed container, such that the expandable member deforms toward the peripheral portion of the base of the partially formed container. A non-temporary storage medium, which involves inserting a fluid into the expandable member in order to expand the expandable member from a first configuration to a second configuration that is expanded beyond the first configuration, so as to push the partially formed container against the inner surface of the mold through a process of forming the container from the partially formed container.

Images