Mandrel System and Method

Abstract

A mandrel system for use with a mold to form a container is described. The mandrel system includes a component, a mandrel, and an expandable member. The mandrel is at least partially disposed within or at least partially disposable within the expandable member and has one or more holes through which fluid can flow from the interior of the mandrel to the exterior of the mandrel to expand the expandable member during use. The expandable member is attachable or attachable to the component. When the expandable member is attached to the component and the mandrel is at least partially disposed within the expandable member, the end of the mandrel is movable relative to the component to vary the length of the expandable member and thereby vary the width of the expandable member.

Description

Technical Field

[0001] The present invention relates to a mandrel system for use with a mold to form a container, and a method of forming a container.

Background Art

[0002] A mandrel system may be inserted into a mold to expand an expandable member of the mandrel system and apply a forming operation to a container, such as a bottle, disposed within the mold. In some examples, after the forming operation is applied, the mandrel system may be withdrawn from the mold.

Summary of the Invention

[0003] According to a first aspect of the present invention, there is provided a mandrel system for use with a mold for forming a container, the mandrel system comprising a component and an expandable member, the mandrel being at least partially disposed within or at least partially disposable within the expandable member, and having one or more holes through which fluid can flow from the interior of the mandrel to the exterior of the mandrel for expanding the expandable member during use, the expandable member being attachable or attachable to the component, and when the expandable member is attached to the component and the mandrel is at least partially disposed within the expandable member, an end of the mandrel is movable relative to the component, changing the length of the expandable member and thereby changing the width of the expandable member. The expandable member can be regarded as an inflatable member or a bladder. As a result, the width of the expandable member can be varied to be most suitable for the requirements of the manufacturing process employing the mandrel system. For example, narrowing the width of the expandable member can have the advantage of facilitating the passage of the expandable member through the opening of the mold that can occur when the mandrel system is inserted into and then withdrawn from the mold. By narrowing the width, the expandable member can pass through the opening without contacting the mold, thereby preventing damage to the expandable member. Further, when the container is disposed within the mold and the expandable member is inserted into the container to apply a forming operation, narrowing the width can reduce the likelihood of the expandable member contacting and damaging the container during insertion and / or withdrawal. Widening the width of the expandable member can be beneficial during the expansion of the expandable member as the expandable member can expand relatively unrestrained by the mandrel. The unrestrained expansion of the expandable member may improve the magnitude and uniformity of the pressure applied to the container by the expandable member during the forming operation. Further, the unrestrained expansion may reduce stress concentration in the expandable member where there is a possibility of damage or fatigue of the expandable member, thereby extending the life of the expandable member.Furthermore, increasing the length of the expandable member may cause tension to be applied to the expandable member, thereby reducing the amount of slack in the expandable member. As a result, the expandable member may be less likely to contact and damage the container during insertion and / or withdrawal. Optionally, the component comprises a connector for connecting the mandrel system to the mold. Optionally, the component is part of the mandrel. In some examples, the container is a bottle, such as a fiber-based bottle. Optionally, the fluid can flow through a hole from outside the mandrel to inside the mandrel during use.

[0004] The expandable member may be attached or attachable to the end of the mandrel. As a result, improved control of the width of the expandable member can be achieved. Specifically, the end of the mandrel may move away from the component, increasing the length of the expandable member and correspondingly narrowing the width of the expandable member. The end of the mandrel may then move towards the component to shorten the length of the expandable member, and the width of the expandable member may correspondingly widen. Optionally, the end of the mandrel may be movable relative to the component in response to expansion of the expandable member.

[0005] The expandable member may be removably attached to the end of the mandrel or may be removably attachable. As a result, the end of the mandrel can be attached to or removed from the expandable member during various stages of the manufacturing process. For example, when the expandable member is attached to the mandrel, it can be more easily positioned and moved. This can be beneficial for positioning the expandable member within the mold before expansion and / or during insertion or extraction of the mandrel system from the mold. When removed from the mandrel, the expandable member can expand without being restrained by the end of the mandrel, which might otherwise restrain the expansion. The unrestrained expansion of the expandable member can improve the magnitude and uniformity of the pressure applied by the expandable member to the container within the mold. Thereby, the quality of the container can be improved by the improvement in compression that can result from the improvement in the magnitude and uniformity of the applied pressure. Further, the unrestrained expansion can reduce stress concentration in the expandable member, which can be a potential for damage or fatigue of the expandable member. Thereby, the lifespan of the expandable member can be extended.

[0006] The expandable member can be arranged to be removed from the end of the mandrel in response to the expansion of the expandable member. Thereby, the expandable member can move freely relative to the end of the mandrel during expansion and can thus expand without being restrained by the end of the mandrel. As described above, the unrestrained expansion of the expandable member can improve the magnitude and uniformity of the pressure applied by the expandable member to the container within the mold. Further, the unrestrained expansion can reduce stress concentration in the expandable member, which can be a potential for damage or fatigue of the expandable member. Thereby, the lifespan of the expandable member can be extended.

[0007] The end of the mandrel may be rotatable relative to the component so as to screw an expandable member centered on the mandrel. By screwing the expandable member around the mandrel, a change in the width of the expandable member larger than when the expandable member is not screwed can be achieved. Thereby, the mandrel system may be usable with a wider range of mold shapes. Specifically, in some molds, the opening may be relatively small, but the mold cavity may be relatively wide. In these cases, a relatively wide expandable member is required to sufficiently fill these mold cavities. However, the expandable member also needs to be small enough to be inserted into and withdrawn from the mold through a relatively small opening. By screwing the expandable member around the mandrel, the mandrel system can be provided with a relatively wide expandable member, and yet the width of the expandable member can be narrowed to allow insertion and withdrawal of the expandable member through the relatively small opening of the mold. Further, the inventors have confirmed that by screwing and extending the expandable member, the twist is more uniformly distributed along the length of the expandable member, thereby allowing for a greater variation in width than when either screwing or extending alone is provided.

[0008] The mandrel may have a cylindrical shape. By having a cylindrical shape, sharp edges along the length of the mandrel are omitted, thereby reducing the possibility that the mandrel damages the expandable member, for example, by punching holes in the expandable member. Optionally, the ends of the mandrel can be rounded. Thereby, sharp edges at the ends of the mandrel can be omitted.

[0009] The mandrel system may comprise a controller configured to move an end of the mandrel relative to a component. Thereby, the amount of operator input required to operate the mandrel system can be reduced, for example, compared to a mandrel system where an operator manually moves the end of the mandrel relative to the component. Thereby, the overall product quality and consistency may be improved. Further, thereby, the processing time may be reduced and the throughput may be improved.

[0010] The end of the mandrel may be movable relative to the component along a longitudinal axis, the end of the mandrel may be rotatable relative to the component about the longitudinal axis, and the controller may be configured to move the end of the mandrel relative to the component along the longitudinal axis and at the same time cause rotation of the end of the mandrel relative to the component about the longitudinal axis. As a result, the expandable member may be able to elongate as it twists. Thereby, the possibility of damage while the expandable member is twisted is reduced, and / or the contraction or expansion of the expandable member becomes faster, thereby reducing the processing time and improving the throughput.

[0011] According to a second aspect of the present invention, a mold system for forming a container is provided, the mold system comprising a mold having a mold cavity and an opening, and the mandrel system of the first aspect, the mandrel system being insertable into the mold cavity through the opening and usable with the mold to form a container within the mold cavity. As described above, the width of the expandable member can thereby be varied to facilitate passage of the expandable member through the opening of the mold. In some examples, the container is a bottle, such as a fiber-based bottle.

[0012] The mandrel system may comprise a reference point and may be positionable relative to the mold such that the reference point is in a fixed position relative to the mold. The mandrel and the expandable member may extend into the mold cavity through an opening such that there is a clearance between the expandable member and the base of the mold cavity on the opposite side of the opening. The ends of the mandrel and the expandable member may be movable relative to the reference point to vary the clearance. As a result, the expandable member can be properly positioned relative to the base. If the expandable member is improperly positioned (e.g., too far from the base), during expansion, the expandable member may contact the upper part of the container within the mold cavity before the expandable member fills the lower part of the container. Further downward expansion of the expandable member may be inhibited by the friction between the expandable member and the upper part of the container. If the expansion is inhibited, the expandable member may not fully fill the lower part of the container. This may result in an incorrect pressure being applied to the lower part of the container (e.g., the base of the container). Thereby, the compression of this part of the container may be insufficient, leading to a possible reduction in the fragility and / or quality of the container. Alternatively, if the expansion is inhibited, the expandable member may overextend to fully fill the lower part of the container. The overextension may reduce the uniformity of the pressure applied to the container by the expandable member. This reduction in uniformity may adversely affect the quality of the container, resulting in, for example, variations in the fragility or thickness of the container. Further, the overextension may fatigue the expandable member, thereby shortening the life of the expandable member or leading to rupture of the expandable member. By having a movable mandrel, proper positioning of the expandable member within the mold cavity becomes possible. As a result, the quality of the container manufactured with the mold system may be improved and / or the life of the expandable member can be extended.

[0013] The components of the mandrel system may include a connector for connecting the mandrel system to the mold, and the reference point may be provided on the connector. The connector may provide a convenient way to position the mandrel system relative to the mold and fix the reference point relative to the mold.

[0014] The end of the mandrel may be movable between a first position and a second position relative to the component, and when the end of the mandrel is in the second position, the width of the expandable member may be less than or equal to the width of the opening. This further reduces the possibility that the expandable member may damage the container, or that the expandable member may be damaged when withdrawn from or inserted into the mold cavity.

[0015] According to a third aspect of the present invention, there is provided a method of forming a container, the method comprising providing a mold including a mold cavity and an opening, providing a mandrel system of the first aspect, moving an end of the mandrel relative to a component when an expandable member is attached to the component and the mandrel is at least partially disposed inside the expandable member, changing the length of the expandable member, thereby changing the width of the expandable member, inserting the mandrel system into the mold cavity through the opening, or withdrawing the mandrel system from the mold cavity through the opening. As a result, the width of the expandable member can be varied to best suit the requirements of the manufacturing process employing the mandrel system. For example, narrowing the width of the expandable member can have the advantage of facilitating the passage of the expandable member through the opening of the mold that can occur when the expandable member is inserted into and then withdrawn from the mold cavity. By narrowing the width, the expandable member can pass through the opening without contacting the mold, thereby preventing damage to the expandable member. Further, when the container is disposed in the mold cavity and the expandable member is inserted into the container to apply a forming operation to the container, narrowing the width can reduce the likelihood of the expandable member contacting and damaging the container during insertion and / or withdrawal. Widening the width of the expandable member can be beneficial during expansion of the expandable member since the expandable member can expand relatively unconstrained by the mandrel. Unconstrained expansion of the expandable member can improve the magnitude and uniformity of the pressure applied to the container by the expandable member during the forming operation. Further, unconstrained expansion can reduce stress concentration in the expandable member where there is a potential for damage or fatigue of the expandable member, thereby extending the life of the expandable member. Further, increasing the length of the expandable member can cause tension to be applied to the expandable member, thereby reducing the amount of slack in the expandable member. Thereby, the expandable member can be less likely to contact and damage the container during insertion and / or withdrawal. Optionally, the method can include expanding the expandable member to apply a forming operation to a container disposed in the mold cavity.In one example, the container is a bottle, such as a fiber-based bottle.

[0016] The method can include at least one of removing the end of the mandrel from the expandable member after inserting the mandrel system into the mold cavity through the opening and attaching the end of the mandrel to the expandable member before withdrawing the mandrel system from the mold cavity through the opening. As a result, the end of the mandrel can be attached to or removed from the expandable member during various stages of the manufacturing process. For example, the expandable member can be more easily positioned and moved when attached to the mandrel. This can be beneficial for positioning the expandable member within the mold before expansion and / or during insertion or removal of the expandable member from the mold cavity through the opening. When removed from the mandrel, the expandable member can expand without being restrained by the end of the mandrel, which otherwise could potentially restrain the expansion. The unrestrained expansion of the expandable member can improve the magnitude and uniformity of the pressure applied by the expandable member to the container within the mold cavity. Thereby, the quality of the container can be improved by the improvement in compression that can result from the improvement in the magnitude and uniformity of the applied pressure. Additionally, the unrestrained expansion can reduce stress concentration in the expandable member, which can be a potential for damage or fatigue of the expandable member. Thereby, the lifespan of the expandable member can be extended.

[0017] The method may include expanding an expandable member and removing the end of the mandrel from the expandable member during expansion of the expandable member. Thereby, the expandable member can move freely relative to the end of the mandrel during expansion and can expand without being restricted by the end of the mandrel. As described above, the unrestricted expansion of the expandable member may improve the magnitude and uniformity of the pressure applied to the container within the mold cavity by the expandable member. Further, the unrestricted expansion may reduce stress concentration in the expandable member, which may be susceptible to damage or fatigue of the expandable member. Thereby, the lifespan of the expandable member can be extended. Alternatively, the method may include expanding the expandable member to apply a forming operation to a container disposed within a mold cavity and moving the end of the mandrel relative to the component during expansion of the expandable member.

[0018] The method can include at least one of rotating an end of the mandrel relative to the component to screw the expandable member around the mandrel and rotating an end of the mandrel relative to the component to unwind the twist of the expandable member around the mandrel. By screwing the expandable member around the mandrel, it may be possible to increase the change in the width of the expandable member compared to when the expandable member is not twisted. This can enable the mandrel system to be used with a wider range of mold shapes. Specifically, in some molds, the opening may be relatively small, but the mold cavity may be relatively wide. In these cases, a relatively wide expandable member is required to sufficiently fill these mold cavities. However, the expandable member also needs to be small enough to be inserted into and withdrawn from the mold through the relatively small opening. By screwing the expandable member around the mandrel, the mandrel system can be provided with a relatively wide expandable member, and yet the width of the expandable member can be narrowed to allow insertion and withdrawal of the expandable member through the relatively small opening of the mold. By unwinding the twist of the expandable member, the expandable member can expand freely without being restrained by being screwed around the mandrel. Furthermore, the inventors have confirmed that by twisting and extending the expandable member, the twist is more uniformly distributed along the length of the expandable member, thereby resulting in a greater width variation than when either twisting or extending alone is provided.

[0019] Rotating an end of the mandrel relative to the component may be performed simultaneously with moving an end of the mandrel relative to the component to change the length of the expandable member. As a result, the expandable member may elongate as it is twisted. This can reduce the likelihood of damage while the expandable member is being twisted and / or can result in a more rapid contraction or expansion of the expandable member.

[0020] The mandrel may have a cylindrical shape. By having a cylindrical shape, sharp edges along the length of the mandrel are omitted, thereby reducing the possibility that the mandrel damages the expandable member, for example, by piercing a hole in the expandable member. Optionally, the ends of the mandrel can be rounded. Thereby, sharp edges at the ends of the mandrel can be omitted.

[0021] Moving the end of the mandrel relative to the component can include moving the component relative to the mold while keeping the end of the mandrel fixed relative to the mold. As a result, the width of the expandable member can be narrowed without the need to move the end of the mandrel relative to the mold in preparation for pulling the expandable member out of the mold cavity. This can enable the end of the mandrel to be positioned near the base of the mold cavity, which can be beneficial as it may be desirable for properly positioning the expandable member within the mold cavity.

[0022] The mandrel system may comprise a reference point, and the method may include moving the mandrel and the expandable member relative to the reference point to change the clearance between the expandable member and the base of the mold cavity on the opposite side of the mold opening, and positioning the mandrel system relative to the mold such that the reference point is in a fixed position relative to the mold and the mandrel and the expandable member extend into the mold cavity through the opening. As a result, the expandable member can be properly positioned relative to the base. If the expandable member is improperly positioned (e.g., too far from the base), during expansion, the expandable member may contact the upper part of the container within the mold cavity before the expandable member fills the lower part of the container. Further downward expansion of the expandable member can be inhibited by the friction between the expandable member and the upper part of the container. If the expansion is inhibited, the expandable member may not completely fill the lower part of the container. This can cause an incorrect pressure to be applied to the lower part of the container (e.g., the base of the container). Thereby, this part of the container may not be sufficiently compressed, and the vulnerability of the container may occur. Alternatively, if the expansion is inhibited, the expandable member may be overly extended to completely fill the lower part of the container. The excessive extension may reduce the uniformity of the pressure applied to the container by the expandable member. This reduction in uniformity can have an adverse effect on the quality of the container, for example, resulting in variations in the vulnerability or thickness of the container. Further, the excessive extension may fatigue the expandable member, thereby shortening the life of the expandable member or leading to the rupture of the expandable member. Optionally, the components of the mandrel system comprise connectors, the connectors comprise reference points, and positioning the mandrel system includes connecting the connectors to the mold. The connectors can provide a convenient way to position the mandrel system relative to the mold and fix the reference point relative to the mold.

[0023] Moving the end of the mandrel relative to the component may include moving the end of the mandrel between a first position and a second position relative to the component, and when the end of the mandrel is in the second position, the width of the expandable member may be less than or equal to the width of the opening. This further reduces the possibility that the expandable member may damage the container or be damaged when the expandable member is withdrawn from the mold cavity.

[0024] The method includes providing a container in a mold cavity, the container being at least partially formed from paper pulp, inserting a mandrel system into the container, and expanding an expandable member as part of a forming operation on the container. The choice of paper is more environmentally friendly than plastic. However, when formed from paper pulp, the container is particularly vulnerable to damage by the expandable member when the expandable member is inserted into or withdrawn from the container. By varying the width of the expandable member, the width of the expandable member can be narrowed to reduce the possibility that the expandable member contacts and damages the container during insertion and / or withdrawal. Optionally, the forming operation includes thermoforming. In some examples, the container is a bottle such as a fiber bottle.

[0025] According to a fourth aspect of the present invention, there is provided a container obtainable or obtained from a manufacturing method including the method of the third aspect of the present invention. The container can be a bottle such as a fiber-based bottle. The manufacturing method may include at least one additional process. The at least one additional process may include coating the container to produce a coated container. The at least one additional process may include drying the container or the coated container to produce a dried container. The at least one additional process may include applying a closure to the coated container or the dried container.

[0026] Embodiments of the present invention will be described by way of example only with reference to the accompanying drawings.

Brief Description of the Drawings

[0027]

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DETAILED DESCRIPTION OF THE INVENTION

[0028] The following description presents exemplary embodiments and, together with the drawings, serves to explain the principles of the embodiments of the present invention.

[0029] FIG. 1 shows a process for making a bottle from paper pulp (i.e., capable of forming a basis for 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 a 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 preformed 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 formed container, drying the coated formed container to create a dried container, and applying a closure to the dried container. As will be apparent at least from the following description, variations can be made to the exemplary process to provide alternative forms embodying other examples of the present invention.

[0030] In this example, providing the 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 a shorting agent 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. (For example, the pulp fibers are hydrated for a period of time, such as 2 to 16 hours, and then 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, which means that the cell walls of those fibers are partially delaminated and the wet surfaces of the fibers include protruding hairs or fibrils. 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.

[0031] The resulting treated pulp is stored in a 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 treated pulp is transferred to a mixing station 13 where the treated pulp is diluted with additional water and optionally mixed with one or more additives (either with or instead of the one or more additives provided with the hydrated pulp fiber) to provide a fiber suspension ready for forming.

[0032] 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 a hydraulic ram. In this example, each of the half - molds is a monolithic or unitary tool formed by additive manufacturing (e.g., 3D printing) that defines a mold profile. 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.

[0033] In FIG. 1, unlike the molding process of dipping the mold into the slurry, the fiber suspension (also known as 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., metering) 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 in 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 because the fibers remain on the walls of the porous mold 15 to form the embryo of the formed container.

[0034] 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 foldable 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 strengthens the wet embryo so that it can be processed, 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, expanding the expansion element 19 radially to 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).

[0035] Demolding is performed when the porous mold 15 opens to remove the self-supporting molded 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 emitted radially is inserted into the mold cavity. Thereby, the fibers are removed from the wall 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 for conditioning 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.

[0036] 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 a surface finish including optionally embossed and / or debossed surface features. After the two halves of the mold 25 are closed around the container 22, a press 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 side walls are more compressed compared to the state at demolding from the porous mold 15.

[0037] 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 prior to thermoforming. However, forming with the mold 25 requires some water content to assist 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, a microwave or other drying process may be performed at multiple stages of the overall manufacturing process.

[0038] 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 with a liquid that coats the inner wall of the formed container 22 instead. In practice, such a coating provides 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.

[0039] 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. Next, one or more additional drying or curing processes may 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.

[0040] FIG. 2 shows a mold system 101 that can be used to thermoform the self-supporting formed container 22 described above. The mold system 101 includes a mold 103, a mandrel system 105, a pump 107, and a line 109.

[0041] The mold 103 includes a first part 111 and a second part 113. In other examples, the mold 103 may include three or more parts. The two parts 111, 113 are separable to open the mold 103. Each part includes a cavity. When the two parts 111, 113 are joined to close the mold 103, a mold cavity 115 is created within the mold 103 that includes the cavities of the first part 111 and the second part 113. In this particular example, the mold cavity 115 has the shape of a bottle and includes a body portion and a neck portion. The neck portion has a smaller diameter than the body portion and extends to the upper part of the mold 103. The mold 103 includes an opening 117 to the mold cavity 115. Further, the mold cavity 115 includes a base 119 on the opposite side of the opening 117. The base 119 is at a fixed distance from the opening 117. That is, the base 119 does not move relative to the opening 117. Thereby, a relatively robust and inexpensive mold can be provided as compared to a mold having a base movable relative to the opening.

[0042] The mandrel system 105 includes a connector 121, a mandrel 123, an expandable member 125, a first actuator 127, a second actuator 129, a controller 131, and a control panel (not shown).

[0043] The connector 121 includes a bore 122 that extends through the connector 121 from the upper part to the bottom part of the connector 121. An annular seal is disposed within the bore 122 to provide a seal between the connector 121 and the mandrel 123, which extends through the bore 122. The seal is a low friction seal that allows movement of the mandrel 123 relative to the connector 121. In this example, the connector 121 includes a reference point 133. As will be described in more detail below, when inserting and removing the mandrel 123 and the expandable member 125 into and from the mold 102, the mandrel 123 moves relative to the reference point 133. In other examples, the reference point 133 may be provided by other components of the mandrel system 105.

[0044] The mandrel 123 comprises a cylindrical tube 134 and a first part 137 of the attachment mechanism of the mandrel system 105. A plurality of holes 135 are formed along the length of the tube 134. The holes 135 are arranged along the lower part of the tube 134 and extend radially through the tube 134 to allow fluid to flow from the inside of the mandrel 123 to the outside of the mandrel 123. The first part 137 of the attachment mechanism comprises a magnet arranged at the lower end of the mandrel 123, i.e., at the end of the mandrel 123 disposed inside the expandable member 125. The mandrel 123 extends into the expandable member 125 through the bore 122 of the connector 121 such that the lower part of the mandrel 123 is disposed inside the expandable member 125. In some examples, the mandrel 123 may be entirely disposed inside the expandable member 125 and different connectors 121 may be used. The upper part of the mandrel 123 is connected to the line 109. The mandrel 123 is movable freely with respect to the connector 121 and thus with respect to the reference point 133. In particular, the mandrel 123 can move freely up and down within the bore 122 and can rotate within the bore 122 of the connector 121.

[0045] The expandable member 125 comprises an inflatable member in the form of an elastomeric bladder 138. The bladder 138 comprises a neck portion and a body portion. The neck portion is sealingly connected to the bottom of the connector 121. The neck portion has a smaller diameter than the body portion. In other examples, the bladder 138 may comprise a single portion of constant diameter. The second component 139 of the attachment mechanism comprises a metal plate 139 formed from a ferromagnetic metal such as iron. The metal plate 139 is attached to the bottom of the bladder 138. The metal plate 139 cooperates with the magnet 137 of the mandrel 123 to removably attach the expandable member 125 to the mandrel 123.

[0046] The first actuator 127 is disposed on the connector 121 and coupled to the mandrel 123. By the operation of the first actuator 127, the mandrel 123 linearly moves relative to the reference point 133 along the longitudinal axis of the mandrel 123. In this example, the first actuator 127 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 123. In other examples, the first actuator 127 may include a hydraulic or pneumatic system for moving the mandrel 123 relative to the reference point 133.

[0047] The second actuator 129 is disposed at the upper end of the mandrel 123 and coupled to the mandrel 123. By the operation of the second actuator 129, the mandrel 123 rotates about the longitudinal axis of the mandrel 123 relative to the reference point 133. In this example, the second actuator 129 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 123. In other examples, the second actuator 129 may include a hydraulic or pneumatic system for rotating the mandrel 123 relative to the reference point 133.

[0048] In this example, the mandrel system 105 includes separate actuators 127, 129 for linearly moving the mandrel 123 and for rotating the mandrel 123. Thus, this improves the control over the linear and rotational movement of the mandrel 123 and enables independent control over the rotational and linear movement. In other examples, the mandrel system 105 may include a single actuator operable to linearly move the mandrel 123 and rotate it simultaneously. In a further example, the actuator may include a single electric motor, and one or more of the transmissions may be clutch-type. In this way, the advantages of independent control over the linear and rotational movement of the mandrel can be achieved using a single electric motor. The controller 131 controls the operation of the actuators 127, 129 and thereby controls the movement of the mandrel 123 relative to the reference point 133. The controller 131 also controls a robot arm (not shown) that moves the connector 121 relative to the mold 103 and the pump 107.

[0049] A control panel (not shown) is connected to the controller 131 and is for receiving instructions and data related to the mold 103 and the expandable member 125.

[0050] The pump 107 includes a cylinder for moving fluid within the line 109. In some examples, the fluid is one of air, water, or oil. Since the line 109 is connected to the top of the mandrel 123, moving the fluid causes the pump 107 to supply pressurized fluid inside the mandrel 123. The pressurized fluid then flows into the expandable member 125 through the hole 135 in the tube 134. Thereby, the pump 107 is used to expand the expandable member 125. The pump 107 can also operate in the opposite direction to draw fluid out of the expandable member 125 and thereby contract and shrink the expandable member 125.

[0051] Here, the use of the mold system 101 is provided with reference to FIG. 3. As shown in FIG. 3(a), the two parts 111, 113 of the mold 103 are closed around the container 22 such that the container 22 is disposed inside the mold cavity 115. At this stage, the mandrel system 105 is disposed outside the mold cavity 115. The magnet 137 is attached to a magnetic plate 139 that attaches the expandable member 125 to the end of the mandrel 123.

[0052] Referring now to FIG. 3(b), the controller 131 controls the first actuator 127 to move the mandrel 123 downward with respect to the reference point 133. As the mandrel 123 moves downward, the end of the mandrel 123 pushes the bottom of the expandable member 125 downward, thereby increasing the length of the expandable member 125. This increase in the length of the expandable member 125 correspondingly decreases the width of the expandable member 125. At the same time, the controller 131 operates the second actuator 129 to rotate the mandrel 123 with respect to the reference point 133. Since the expandable member 125 is attached to the end of the mandrel 123 by an attachment mechanism (i.e., the magnet 137 and the metal plate 139), rotation causes the expandable member 125 to be twisted about the mandrel 123. By twisting and elongating the expandable member 125, the width of the expandable member 125 can be made even narrower than by twisting and elongating it alone.

[0053] Next, the controller 131 controls the actuators 127, 129 to stop the downward movement and rotation of the mandrel 123. At this stage, the width of the expandable member 125 is less than or equal to the width of the opening 117 of the mold 103. Thereby, the mandrel 123 and the expandable member 125 can pass through the opening 117 of the mold 103 without the expandable member 125 contacting the mold 103 or the container 22. Advantageously, this can reduce the possibility that the container 22 is damaged by the expandable member 125 and the possibility that the expandable member 125 is damaged by the mold 103.

[0054] Referring to FIG. 3(c) here, the controller 131 controls the robotic arm to move the connector 121 downward toward the mold 103 until the connector 121 contacts and connects to the upper part of the mold 103 (shown in FIG. 3(d)). As the connector 121 descends, the mandrel 123 and the expandable member 125 are inserted into the mold cavity 115 through the opening 117. Due to the previous downward movement of the mandrel 123 with respect to the connector 121 (described with reference to FIG. 3(b)), the length of the mandrel 123 is too long to fit within the mold cavity 115. Therefore, when a mandrel 123 of a predetermined length is inserted into the mold cavity 115, the controller 131 operates the first actuator 127 to move the mandrel 123 upward with respect to the connector 121. This upward movement of the mandrel 123 occurs at the same movement speed as the connector 121 moves downward toward the mold 103. As a result, the position of the mandrel 123 within the mold appears to be stationary. The upward movement of the mandrel 123 with respect to the connector 121 reduces the length of the expandable member 125 and widens the width of the expandable member 125.

[0055] When the connector 121 contacts and connects to the upper part of the mold 103, the controller 131 controls the robot arm to stop the downward movement of the connector 121. Further, the controller 131 controls the first actuator 127 to stop the upward movement of the mandrel 123 with respect to the connector 121. As shown in FIG. 3(d), in the state where the connector 121 is connected to the upper part of the mold 103, the reference point 133 is at a fixed position with respect to the mold 103. At this stage, the clearance between the base 119 of the mold cavity 115 and the bottom of the expandable member 125 is indicated by the length of the mandrel 123 extending directly below the connector 121. This clearance is the minimum separation distance between the base 119 of the mold cavity and the expandable member 125 when the reference point 133 is at a fixed position with respect to the mold 103. By changing the length of the mandrel 123 extending below the connector 121, the controller 131 can change the clearance. The controller 131 controls the first actuator 127 (and thus the length of the mandrel 123 extending below the connector 121) so that the clearance has a predetermined value. Thus, the bottom of the expandable member 125 can be properly positioned with respect to the base 119. This will be described in more detail below.

[0056] Next, the controller 131 operates the second actuator 129 to rotate the mandrel 123 with respect to the reference point 133 to straighten the expandable member 125 from the center of the mandrel 123. Then, thereby, the width of the expandable member 125 further expands.

[0057] Here, with the expandable member 125 positioned within the mold cavity 115, the forming operation is performed with the container 22 (FIG. 3(e)). The controller 131 controls the pump 107 such that pressurized fluid is supplied to the mandrel 123. The pressurized fluid flows through the holes 135 of the mandrel 123 into the expandable member 125, expanding the expandable member 125. The expansion of the expandable member 125 applies a force to the bottom of the expandable member 125, which overcomes the magnetic attraction between the magnet 137 and the metal plate 139, separating the expandable member 125 from the end of the mandrel 123. The expandable member 125 continues to expand within the container. When fully expanded, the expandable member 125 contacts the container 22, compressing the container 22 against the mold 103 to form the container 22.

[0058] Referring now to FIG. 3(f), when the forming operation is complete, the controller 131 controls the pump 107 to draw the pressurized fluid from the expandable member 125, thereby contracting and reducing the expandable member 125. When the expandable member 125 contracts, the attraction between the magnet 137 and the metal plate 139 is sufficient to reattach the expandable member 125 to the end of the mandrel 123.

[0059] Next, the controller 131 controls the robot arm to move the connector 121 upward with respect to the mold 103 (FIG. 3(g)). At the same time, the controller 131 controls the first actuator 127 to move the mandrel 123 downward with respect to the reference point 133 at the same speed as the connector 121 moves upward so that the end of the mandrel 123 remains stationary with respect to the mold 103. Thereby, the length of the expandable member 125 increases, and as a result, the width of the expandable member 125 becomes narrower. The control device 131 also controls the second actuator 129 to rotate the mandrel 123 with respect to the reference point 133 so that the expandable member 125 is twisted about the mandrel 123 to further narrow the width of the expandable member 125. With the expandable member 125 being extended and twisted about the mandrel 123, the controller 131 controls the actuators 127 and 129 to stop the movement of the mandrel 123 with respect to the reference point 133.

[0060] Referring now to FIG. 3(h), the controller 131 controls the robot arm to move the connector 121 upward with respect to the mold 103 and withdraw the mandrel 123 and the expandable member 125 from the mold 103 through the opening 117. When the mandrel 123 and the expandable member 125 are withdrawn from the mold 103, the mold 103 is opened by separating the two parts 111 and 113, and the container 22 is removed for further processing. For example, the container 22 can be dried at the drying stage 29 as described above with reference to FIG. 1.

[0061] By moving the mandrel 123 and the expandable member 125 relative to the reference point 133, the bottom of the expandable member 125 can be properly positioned relative to the base 119. If the bottom of the expandable member 125 is improperly positioned (e.g., if the bottom is too far from the base 119 of the mold), during expansion, the expandable member 125 may contact the upper part of the container 22 before the expandable member 125 fills the lower part of the container 22. Further downward expansion of the expandable member 125 may be inhibited by the friction between the expandable member 125 and the upper part of the container 22. When the expansion is inhibited, the expandable member 125 may not completely fill the lower part of the container 22. As a result, incorrect pressure may be applied to the lower part of the container 22 (e.g., the base of the container 22). Consequently, this part of the container 22 may not be sufficiently compressed, and the container 22 may become vulnerable. Alternatively, when the expansion is inhibited, the expandable member 125 may extend excessively to completely fill the lower part of the container 22. When it extends excessively, it may reduce the uniformity of the pressure applied to the container 22 by the expandable member 125. This reduction in uniformity may adversely affect the quality of the container 22, for example, the container 22 may become vulnerable or the thickness may become non-uniform. Furthermore, excessive elongation may fatigue the expandable member 125, thereby shortening the life of the expandable member 125 or leading to rupture of the expandable member 125. Having the movable mandrel 123 enables proper positioning of the expandable member 125 within the mold cavity 115. As a result, the quality of the container manufactured by the mold system 101 may be improved and / or the life of the expandable member 125 may be improved.

[0062] By moving the mandrel 123 relative to the connector 121 to change the length of the expandable member 125, and thereby changing the width of the expandable member 125, the width of the expandable member 125 can be changed to the one most suitable for the requirements of the manufacturing process using the mandrel system 105. For example, narrowing the width of the expandable member 125 has the advantage that the expandable member 125 can more easily pass through the opening 117 of the mold 103 when the expandable member 125 is inserted into the mold 103 and then withdrawn therefrom. By narrowing the width, the expandable member 125 can pass through the opening 117 without contacting the mold 103, and damage to the expandable member 125 can be avoided. Further, by narrowing the width, the possibility that the expandable member 125 contacts and damages the container 22 during insertion and / or withdrawal can be reduced. Widening the width of the expandable member 125 can be beneficial during the expansion of the expandable member 125 because the expandable member 125 can be expanded relatively unrestrained by the mandrel 123. The unrestrained expansion of the expandable member 125 may improve the magnitude and uniformity of the pressure applied to the container 22 by the expandable member 125 during the forming operation. Further, the unrestrained expansion may reduce the stress concentration in the expandable member 125 where there is a possibility of damage or fatigue of the expandable member 125, thereby improving the life of the expandable member.

[0063] In the above example, the end of the mandrel 123 is removably attached to the expandable member 125. As a result, the end of the mandrel 123 can be attached to or removed from the expandable member 125 during various stages of the manufacturing process. For example, the expandable member 125 can be more easily positioned and moved when attached to the mandrel 123. This can be beneficial for positioning the expandable member 125 within the mold 103 before expansion and / or during insertion or extraction of the expandable member 125 from the mold 103. When removed from the mandrel 123, the expandable member 125 can expand without being restrained by the mandrel 123. The unrestrained expansion of the expandable member 125 may improve the magnitude and uniformity of the pressure applied by the expandable member 125 to the container 22 of the mold 103. Thereby, since the magnitude and uniformity of the applied pressure are improved and the compression is improved, the quality of the container 22 may be improved. Further, the unrestrained expansion may reduce stress concentration in the expandable member 125, which may cause damage or fatigue of the expandable member 125. Thereby, the lifespan of the expandable member 125 can be improved.

[0064] In the above example, the clearance between the bottom of the expandable member, which is after insertion but before expansion, and the mold base has a predetermined value of 8 mm. However, other values may be used for the clearance. As described above, as the clearance between the bottom of the expandable member and the mold base decreases, the possibility of inhibiting the downward expansion of the expandable member 125 decreases. This can reduce the possibility of insufficient compression leading to the vulnerability of the container 22 and / or the possibility of excessive stretching of the expandable member 125 leading to fatigue of the expandable member 125. However, as the clearance decreases, the possibility of non-optimal expansion of the expandable member 125 increases. Specifically, the expandable member 125 may come into early contact with the base of the container 22, which may thereby inhibit the expandable member 125 from subsequently expanding outward toward the corners of the container 22. This may result in a decrease in the quality of the container 22 and / or a shortening of the lifespan of the expandable member 125 as described above. A good balance between the conflicting needs of reducing the possibility of inhibiting downward expansion and reducing the possibility of non-optimal expansion can be achieved with a clearance of 11 mm or less and 2 mm or more.

[0065] The user may manually enter the required clearance (e.g., via a control panel), but in this example, the controller 131 is configured to select or determine a predetermined clearance based on the characteristics of the mold 103 and the characteristics of the expandable member 125. In the example, the controller 131 receives the characteristics of the mold 103 and the characteristics of the expandable member 125 via the control panel. Next, the controller 131 selects a predetermined clearance from an indexed look-up table using the received characteristics of the mold 103 and the received characteristics of the expandable member 125. Thereby, when different molds or different expandable members are used, the operator does not need to calculate a new clearance. Thereby, the downtime occurring when switching between molds can be reduced. The look-up table may have been previously generated through experiments and process modeling to determine predetermined values optimal for different characteristics. The characteristics of the mold 103 may be one of the height, width, and shape of the mold 103. The characteristics of the expandable member 125 may also be one of the height, width, shape, and elasticity of the expandable member 125.

[0066] Referring now to FIG. 4, the mold system 101 further includes an additional mold 201. The additional mold 201 includes an additional mold cavity 203 having a shape different from that of the mold cavity 115. Specifically, the height of the additional mold cavity 203 is lower than the height of the mold cavity 115. As a result, various container sizes can be formed using the mold system 101. Regardless of the shapes of the mold cavities 115, 203, the controller 131 moves the mandrel 123 and the expandable member 125 so that the clearance between the bottom of the expandable member 125 and the bases 119, 205 of the mold cavities 115, 203 is the same predetermined value. As a result, the expandable member 125 can be properly positioned with respect to each of the molds 103, 201 without requiring a custom mandrel and expandable member for each of the molds 103, 201. Thereby, not only is the cost of the mold system 101 reduced, but the processing time can be shortened by eliminating the need to switch the mandrel 123 and the expandable member 125 when switching the molds 103, 201.

[0067] In the above example, the first portion 137 of the attachment mechanism includes a magnet 137, and the second portion 139 of the attachment mechanism includes a magnetically attractable element in the form of a metal plate 139. Similarly, in other examples, the first portion 137 and the second portion 139 may include a plug and socket, or a clamp and a clampable structure. In fact, it is also conceivable that the attachment mechanism is a single part disposed on either the mandrel 123 or the expandable member 125, for example, a clamp on the mandrel 123 that clamps a part of the expandable member 125.

[0068] In the above example, the connector 121 contacts and connects to the upper part of the mold 103. However, in other examples, the connector 121 may not contact or connect to the upper part of the mold 103. Instead, the connector 121 may be moved downward until it reaches a predetermined position above the upper part of the mold 103 while the mandrel 123 and the expandable member 125 extend into the mold 103. In this example, when the connector 121 is in the predetermined position, the reference point 133 is in a fixed position relative to the mold 103.

[0069] In the above example, the movement of the connector 121 and the mandrel 123 is controlled by the controller 131. However, it is also conceivable that the operator can manually control the movement. However, by adopting a controller, the overall product quality can be improved, the processing time can be shortened, and the throughput can be improved.

[0070] In the above example, the mandrel 123 and the expandable member 125 of the mandrel system 105 are inserted into and withdrawn from the mold cavity 115 through the opening 117. It will be understood that it is not necessary to insert the entire mandrel system 105. Therefore, being inserted means that at least a part of the mandrel system 105 is inserted.

[0071] In the above example, the mandrel system 123 includes attachment mechanisms 137, 139 for removably attaching the expandable member 125 to the mandrel 123. However, in other examples, the attachment mechanism may be omitted. For example, FIG. 5 shows an example of a mandrel system 301 in which the expandable member 125 is fixedly attached to the mandrel 123. The mandrel system 301 is the same as the mandrel system of FIG. 2 but is different in the following points.

[0072] The attachment mechanisms 137, 139 are omitted, and the bottom of the main body portion of the expandable member 125 is fixedly attached to the lower end of the mandrel 123.

[0073] The first actuator 303 is operable in a first mode and a second mode. In the first mode, the first actuator 303 moves the mandrel 123 linearly with respect to the reference point 133 along the longitudinal axis of the mandrel 123. In the second mode, the first actuator 303 enables the mandrel 123 to move freely with respect to the reference point 133. For example, the first actuator 303 may be disengaged from the mandrel 123 (e.g., using a clutch) in the second mode, allowing the mandrel 123 to move freely. In another example, the first actuator 303 may be set to an idle mode, in which the first actuator 303 remains coupled to the mandrel 123 but provides little or no resistance to the movement of the mandrel 123. In an example where the first actuator 303 comprises a hydraulic system, the hydraulic system may be open to the atmosphere in the idle mode.

[0074] Referring now to FIG. 6, the mandrel system 301 operates in the same manner as the mandrel system of FIG. 2, but differs in the following respects.

[0075] The extensible member 123 remains attached to the mandrel 125 throughout all operating phases. The controller 131 operates the first actuator 127 in the first mode to move the mandrel 123 vertically with respect to the reference point 133.

[0076] To perform the forming operation of the container 22 (FIG. 6(e)), the controller 131 controls the pump 107 so that the pressurized fluid is supplied to the mandrel 123. The pressurized fluid flows into the expandable member 125 through the holes 135 of the mandrel 123 and expands the expandable member 125. At the same time, the controller 131 operates the first actuator 303 in the second operation mode, whereby the mandrel 123 can move freely with respect to the reference point 133. As a result, the mandrel 123 does not inhibit the expansion of the expandable member 125. Due to the expansion of the expandable member 125, the mandrel 123 moves downward toward the base 119 of the mold 103. The expandable member 125 continues to expand within the container 22. When fully expanded, the expandable member 125 contacts the container 22 and compresses the container 22 against the mold 103 to form the container 22.

[0077] Referring now to FIG. 6(f), when the forming operation is completed, the controller 131 controls the pump 107 to draw the pressurized fluid from the expandable member 125, thereby contracting and shrinking the expandable member 125. The first actuator 303 continues to operate in the second mode. As a result, as the expandable member 125 contracts, the mandrel 123 moves upward together with the bottom of the expandable member 125.

[0078] In the example of FIG. 5, the mandrel 123 is movable relative to the connector 121 in response to the expansion of the expandable member 125. As a result, the expandable member 125 can expand relatively unconstrained by the mandrel 123 while still being attached to the mandrel 123. By being attached to the mandrel 123, it becomes beneficially possible for the mandrel 123 to manipulate the expandable member 125, whereby the function of the mandrel system 301 can be improved.

[0079] In the example of FIG. 5, when operating in the second mode, the first actuator 303 allows the mandrel 123 to move freely relative to the reference point 133. However, in other examples, when operating in the second mode, the first actuator 303 may instead actively move the mandrel 125 in response to the expansion of the expandable member 125. Specifically, during the expansion of the expandable member 125, the first actuator 303 may move the mandrel 123 downward toward the base 119 of the mold 103 at a speed that likely corresponds to the expansion of the removed expandable member 125 in FIG. 3(e). During the subsequent contraction of the expandable member 125, the first actuator 303 can contract the expandable member 125 by moving the mandrel 123 away from the base 119 of the mold 103.

[0080] In the example of FIG. 5, the mandrel 125 is integral, which can provide a relatively simple and robust mandrel. However, in other examples, the mandrel may be a mandrel consisting of multiple parts. For example, FIG. 7 shows an example of a mandrel system 401 including a mandrel 403 consisting of two parts. The mandrel system 401 is the same as the mandrel system of FIG. 5 but differs in the following points.

[0081] The mandrel 403 includes a first part 405 and a second part 407. The first part 405 has a cylindrical tube and includes a plurality of holes 135 formed along the length of the first part 405. The holes 135 are arranged along the lower part of the first part 405 and extend radially through the first part 405 to allow fluid to flow from the inside of the mandrel 403 to the outside of the mandrel 403.

[0082] The second portion 405 has a cylindrical shape and an outer diameter smaller than the inner diameter of the first portion 409. The second portion 407 is disposed inside the first portion 405 at the lower end of the first portion 405. The end of the second portion 407 is attached to the body portion of the expandable member 125. The second portion 407 is keyed to the first portion 405 such that the second portion 407 moves linearly with respect to the first portion 405 but is prevented from rotating with respect to the first portion 405. For example, the first portion 405 may comprise a channel extending parallel to the longitudinal axis of the first portion 405, and the second portion 407 may comprise a protrusion received within the channel. The second portion 407 moves along the longitudinal axis of the first portion 405 between a contracted position and an extended position. The length of the mandrel 403 is longer in the extended position than in the contracted position.

[0083] The first and second actuators 409, 411 are similar to the actuators 303, 129 of FIG. 5, except that the first actuator 409 operates only in the first mode. The actuators 409, 411 are each coupled to the first portion 405 of the mandrel. The first actuator 409 is operable to linearly move the first part 405 of the mandrel 403 along the longitudinal axis of the mandrel 403 with respect to the connector 121 and the reference point 133. The second actuator 411 is operable to rotate the first portion 405 of the mandrel 403 with respect to the connector 121 and the reference point 133. Since the first portion 405 is keyed to the second portion 407 of the mandrel 403, rotation of the first portion 405 causes the second portion 407 to rotate as well.

[0084] Referring now to FIG. 8, the mandrel system 401 operates in the same manner as the mandrel system of FIG. 5, but differs in the following respects.

[0085] As shown in FIG. 8(a), the operation of the mandrel system 401 begins with the two parts 111, 113 of the mold 103 being closed around the container 22 such that the container 22 is disposed inside the mold cavity 115. At this stage, the mandrel system 401 is disposed outside the mold cavity 115, and the expandable member 125 is in a contracted state. In the contracted state, the length of the mandrel 403 extending below the connector 121 is the same as the natural (unstretched) length of the expandable member 125. Thereby, when the expandable member 125 is in a contracted state, the second portion 407 of the mandrel 403 is biased by the expandable member 125 toward the contracted position. Specifically, due to the elasticity of the expandable member 125, the second portion 407 is biased toward the contracted position.

[0086] To perform the forming operation of the container 22 (FIG. 8(e)), the controller 131 controls the pump 107 such that pressurized fluid is supplied to the mandrel 403. The pressurized fluid flows into the expandable member 125 through the hole 135 of the mandrel 403, expanding the expandable member 125. As the expandable member 125 expands, the bottom of the expandable member 125 moves downward toward the base 119 of the mold 103. As the bottom of the expandable member 125 moves downward, the second portion 407 of the mandrel 403 moves from the contracted position to the extended position. The expandable member 125 continues to expand within the container 22. When fully expanded, the expandable member 125 contacts the container 22 and compresses the container 22 against the mold 103 to form the container 22.

[0087] Referring now to FIG. 8(f), when the forming operation is complete, the controller 131 controls the pump 107 to draw the pressurized fluid from the expandable member 125, thereby contracting and shrinking the expandable member 125. As the expandable member 125 contracts, the bottom of the expandable member 125 moves upward away from the base 119 of the mold 103. As the bottom of the expandable member 125 moves upward, the second portion 407 of the mandrel 403 moves from the contracted position to the extended position.

[0088] In the example of FIG. 7, the expandable member 125 is attached to the second portion 407 of the mandrel 403, and the second portion 407 moves relative to the first portion 405 in response to the expansion of the expandable member 125. As a result, the above-described advantage that the expandable member 125 can expand relatively unrestrained while being attached to the mandrel 403 can be achieved. Further, by providing the mandrel 403 consisting of two parts, a convenient means can be provided that allows the end of the mandrel 403 to move relative to the connector 121 in response to the expansion of the expandable member.

[0089] In the example of FIG. 7, the first part 405 of the mandrel 403 is movable relative to the connector 121. However, in other examples, it is conceivable that the first part 405 of the mandrel 403 is fixedly attached to the connector 121, such that it is immovable relative to the reference point 133. In this example, the connector 121 and the first part 405 are moved together during the insertion and extraction of the mandrel 403 and the expandable member 125. During the expansion and contraction of the expandable member 125, the second portion 407 of the mandrel 403 is still able to move relative to the first portion 405 of the mandrel 403, whereby the expansion and contraction of the expandable member 125 continues without being inhibited by the mandrel 403.

[0090] In the above example, the movement of the mandrel 123 relative to the reference point 133 is controlled such that the clearance between the bottom of the expandable member 125 and the base 119 of the mold 103 can be varied. However, in other examples, it is also conceivable that the movement of the mandrel 123 relative to the reference point 133 may not change the clearance. For example, the lower end of the mandrel 123 may not be attached to the bottom of the expandable member 125. In that case, the clearance between the bottom of the expandable member 125 and the base 119 of the mold 103 is defined by the natural (unstretched) length of the expandable member 125. When the connector 121 is moved upward relative to the mandrel 123, the end of the mandrel 123 contacts the bottom of the expandable member 125, applying a force to increase the length and thereby narrowing the width of the expandable member 125. When the connector 121 is moved downward relative to the mandrel 123, the force is then removed, and as a result, the expandable member 125 returns to its natural length and width. This arrangement can achieve the above-described advantage of varying the width of the expandable member 125 in accordance with the requirements of the manufacturing process, but may not realize the above-described advantage of properly positioning the expandable member 123. Nevertheless, since the clearance is defined by the natural length of the expandable member 125, the expandable member 125 can be optimized for a particular shape of the mold 103.

[0091] Exemplary embodiments of the invention have been described with reference to the illustrated examples. However, it will be understood that changes and modifications may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A mandrel system for use with a mold to form a container, wherein the mandrel system is Components and Mandrel and, Equipped with expandable components, The mandrel is at least partially located inside the expandable member, or can be at least partially located inside the expandable member, and comprises one or more holes through which fluid can flow from inside the mandrel to outside the mandrel in order to expand the expandable member during use. The expandable member is attached to or can be attached to the component, The mandrel system, wherein the expandable member is attached to the component and the mandrel is positioned at least partially inside the expandable member, the end of the mandrel is movable relative to the component to change the length of the expandable member, thereby changing the width of the expandable member.

2. The mandrel system according to claim 1, wherein the expandable member is attached to or can be attached to the end of the mandrel.

3. The mandrel system according to claim 2, wherein the expandable member is detachably attached to or detachably attached to the end of the mandrel.

4. The mandrel system according to claim 3, wherein the expandable member is arranged to be removed from the end of the mandrel in accordance with the expansion of the expandable member.

5. The mandrel system according to claim 1, wherein the end of the mandrel is rotatable relative to the component so as to twist the expandable member around the mandrel.

6. The mandrel system according to claim 1, wherein the mandrel is cylindrical in shape.

7. The mandrel system according to claim 1, further comprising a controller configured to move the end of the mandrel relative to the component.

8. The end of the mandrel is movable relative to the component along the longitudinal axis, The end of the mandrel is rotatable relative to the component about the longitudinal axis, The mandrel system according to claim 7, wherein the controller is configured to move the end of the mandrel relative to the component along the longitudinal axis and at the same time cause the end of the mandrel to rotate relative to the component about the longitudinal axis.

9. A mold system for forming a container, wherein the mold system is A mold having a mold cavity and an opening, The mandrel system is as described in claim 1, The mold system, wherein the mandrel system is insertable into the mold cavity through the opening and can be used together with the mold to form the container within the mold cavity.

10. The mandrel system includes a reference point, The mandrel system is positionable relative to the mold such that the reference point is in a fixed position relative to the mold, and the mandrel and the expandable member extend through the opening into the mold cavity such that there is a clearance between the expandable member and the base of the mold cavity on the opposite side of the opening. The mold system according to claim 9, wherein the end of the mandrel and the expandable member are movable relative to the reference point to change the clearance.

11. The mold system according to claim 10, wherein the component of the mandrel system comprises a connector for connecting the mandrel system to the mold, and the reference point is provided on the connector.

12. The end of the mandrel is movable between a first position and a second position relative to the component. The mold system according to claim 9, wherein when the end of the mandrel is in the second position, the width of the expandable member is less than or equal to the width of the opening.

13. A method for forming a container, wherein the method is A mold is provided that includes a mold cavity and an opening, The mandrel system described in claim 1 is provided, When the expandable member is attached to the component and the mandrel is positioned at least partially inside the expandable member, the end of the mandrel is moved relative to the component to change the length of the expandable member and thereby change the width of the expandable member. A method comprising inserting the mandrel system into the mold cavity through the opening, or withdrawing the mandrel system from the mold cavity through the opening.

14. The method according to claim 13, comprising at least one of the following: inserting the mandrel system into the mold cavity through the opening, and then removing the end of the mandrel from the expandable member; and attaching the end of the mandrel to the expandable member before withdrawing the mandrel system from the mold cavity through the opening.

15. To extend the expandable member, The method according to claim 13, comprising removing the end of the mandrel from the expandable member during the expansion of the expandable member.

16. The method according to claim 13, comprising at least one of the following: rotating the end of the mandrel relative to the component so as to twist the expandable member around the mandrel; and rotating the end of the mandrel relative to the component so as to untwist the expandable member around the mandrel.

17. The method according to claim 16, wherein the rotation of the end of the mandrel relative to the component is performed simultaneously with the movement of the end of the mandrel relative to the component to change the length of the expandable member.

18. The method according to claim 13, wherein the mandrel is cylindrical in shape.

19. The method according to claim 13, wherein moving the end of the mandrel relative to the component includes moving the component relative to the mold while keeping the end of the mandrel fixed relative to the mold.

20. The mandrel system includes a reference point, Moving the mandrel and the expandable member relative to the reference point to change the clearance between the expandable member and the base of the mold cavity on the opposite side of the opening of the mold, The method according to claim 13, comprising positioning the mandrel system with respect to the mold such that the reference point is in a fixed position with respect to the mold and the mandrel and the expandable member extend through the opening into the mold cavity.

21. Moving the end of the mandrel relative to the component includes moving the end of the mandrel between a first position and a second position relative to the component. The method according to claim 13, wherein when the end of the mandrel is in the second position, the width of the expandable member is less than or equal to the width of the opening.

22. The provision involves providing a container within the mold cavity, wherein the container is at least partially made from paper pulp, Inserting the mandrel system into the container, The method according to claim 13, comprising expanding the expandable member as part of the forming operation on the container.

23. A container obtainable from or obtainable from a manufacturing method comprising the method described in claim 13.

24. The container according to claim 23, wherein the container is a bottle.

25. The container according to claim 23, wherein the container is a fiber bottle.

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