A method and system

Abstract

A method providing a hollow moulded fibre product, and an expandable member comprising a first portion, and a second portion which defines an opening. The first portion is movable towards the opening

Description

TECHNICAL FIELD The present invention relates to methods and systems for processing a hollow moulded fibre product. BACKGROUND It is desirable to reduce glass and plastics use in consumable items, particularly packaging. Non-necked receptacles, such as trays, bowls and other simple shapes, are commonly made from paper pulp. However, a more complex necked receptacle, like a bottle, jar or certain types of vase, is more difficult to engineer due to an internal narrowing of the receptacle between a main body portion of the receptacle and an opening of the receptacle. During manufacture of the necked receptacle, it may be desirable to employ a forming operation to improve properties of the necked receptacle. SUMMARY According to a first aspect of the present invention, there is provided a method comprising providing a hollow moulded fibre product; providing an expandable member comprising a first portion, and a second portion which defines an opening of the expandable member, wherein the expandable member comprises a normal configuration and an inverted configuration, wherein, in the inverted configuration, at least one of: the first portion is located in the second portion, and the expandable member is inside out compared with the normal configuration; moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration; and at least one of: inserting the expandable member, in the inverted configuration, into the hollow moulded fibre product; and withdrawing the expandable member, in the inverted configuration, from the hollow moulded fibre product. Being in the inverted configuration may enable some of the dimensions of the expandable member to be constrained. This may reduce the likelihood of the expandable member contacting the hollow moulded fibre product during insertion and withdrawal. This may enable the expandable member to be inserted into and / or withdrawn from the hollow moulded fibre product with less friction than if the expandable member were inserted and / or withdrawn in the normal configuration. Friction between the hollow moulded fibre product and the expandable member may damage the expandable member and / or the hollow moulded fibre product. The normal configuration is the configuration of the expandable member immediately prior to expansion of the expandable member to apply a forming operation to the hollow moulded fibre product. Optionally, the method comprises moving the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration. Optionally, the hollow moulded fibre product is a necked hollow moulded fibre product, and comprises a main body and a neck; the neck has a width which is less than a width of the main body; the second portion has a width which is less than the width of the neck when the expandable member is in the normal configuration and the inverted configuration, the first portion has a width which is less than the width of the main body and greater than the width of the neck when the expandable member is in the normal configuration. Providing the expandable member with two portions of different width in the normal configuration may enable the expandable member to match the geometry of the necked hollow moulded fibre product more closely when expanded from the normal configuration and thereby more evenly apply pressure to the necked hollow moulded fibre product during the forming operation when compared with an expandable member of constant width in the normal configuration. Optionally, moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration comprises at least one of moving the first portion into the second portion, and moving the first portion through the second portion; and when the first portion is located in the second portion or the first portion is moving through the second portion, a width of the first portion is constrained to be less than the width of the neck as a result of the first portion being located in or moving through the second portion. As the width of the first portion is greater than the width of the neck, the neck may be particularly likely to have rubbing between the first portion and the neck if the expandable member were not inserted and / or withdrawn in the inverted configuration and another method for reducing the width of the first portion were employed. By constraining the width of the first portion to be less than the width of the neck, the likelihood of the first portion rubbing against, and damaging, the neck may be reduced. Inserting and / or withdrawing in the inverted configuration may place less stress on the expandable member, and thereby may increase the life of the expandable member, when compared with other methods of reducing the width of the first portion, such as twisting the expandable member. Optionally, in the inverted configuration, no less than 10% of a length of the first portion is located in the second portion. As a result, the amount of rubbing, and thereby the likelihood of the expandable member and / or the hollow moulded fibre product becoming damaged may be reduced when compared with if less than 10% of the length of the first portion were located in the second portion. Optionally, the width of the second portion of the expandable member is no greater than 99% of the width of the neck when the expandable member is in the inverted configuration. Thereby, a greater clearance may be provided between the second portion and the neck (when compared with having a width of greater than 99%), which may reduce the likelihood of rubbing between, and thereby damage to, the second portion of the expandable member and the neck during the insertion and the withdrawal. Optionally, the width of the second portion is no greater than 98%, 97%, 96%, or 95% of the width of the neck. Decreasing the width of the second portion may increase the clearance and thereby reduce the likelihood of rubbing between the second portion and the neck. Optionally, the method comprises providing a sleeve in the second portion; and moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration comprises at least one of: moving the first portion into the sleeve, and moving the first portion through the sleeve. The sleeve may restrict widening of the second portion caused by the first portion moving into and / or through the second portion as the expandable member is inverted. This may reduce the likelihood of the second portion rubbing along the hollow moulded fibre product when compared with omitting the sleeve. The sleeve may reduce the likelihood of the first portion rubbing against the second portion, which may reduce the likelihood of the expandable member becoming damaged due to the portions of the expandable member rubbing against one another when compared with omitting the sleeve. Optionally, a Young’s modulus of the sleeve is greater than a Young’s modulus of the expandable member. As a result, the sleeve may restrict the widening of the second portion by a greater extent, and thereby reduce the likelihood of the second portion rubbing along the hollow moulded fibre product by a greater extent, than if the sleeve had a lower Young’s modulus that the expandable member. Optionally, a coefficient of friction between the sleeve and the first portion of the expandable member is less than a coefficient of friction between the first portion of the expandable member and the second portion of the expandable member. As a result, a magnitude of the friction between the sleeve and the first portion may be less than if the sleeve were omitted and the first portion rubbed against the second portion. This reduction in friction may reduce the likelihood of the expandable member becoming damaged due to the portions of the expandable member rubbing against one another. Optionally, the expandable member comprises a wall thickness which is constant along a length of the expandable member. Having a constant wall thickness may enable the first portion to be moved into the second portion with less friction being generated between the portions or the first portion and the sleeve than if the wall thickness varied along the length. In contrast, if the wall thickness increased along the length, then the cross-sectional area of the expandable member that would have to pass through the second portion as it is inverted may be progressively increased, increasing the friction and force generated. Optionally, the method comprises applying a pressure to an inside of the expandable member whilst moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration; and the pressure is greater than an ambient pressure on an outside of the expandable member. Applying the pressure whilst transitioning the expandable member to the inverted configuration may reduce the likelihood of the expandable member buckling compared with if the pressure were not applied. If the expandable member buckles, the expandable member may rub against the hollow moulded fibre product which may result in damage to the expandable member and / or the hollow moulded fibre product. The inside of the expandable member may refer to a side of the expandable member which is innermost when the expandable member is in the normal configuration. The outside of the expandable member may refer to a side of the expandable member which is outermost when the expandable member is in the normal configuration. Optionally, the pressure is no less than Ibar. Optionally, the pressure is no greater than 2bar As the pressure increases, the likelihood of buckling many be reduced. Conversely, increasing the pressure may result in the extent of expansion of the expandable member increasing, which may increase the likelihood of the expandable member rubbing against the hollow moulded fibre product, and / or inhibit the movement of the first portion into the second portion. Applying a pressure of no less than Ibar and no greater than 2bar may provide a good balance between reducing the likelihood of buckling whilst also reducing the extent of expansion of the expandable member. Optionally, the method comprises: providing a mandrel in the expandable member and attached to the first portion of the expandable member; and moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration comprises moving a point of attachment of the mandrel to the expandable member towards the opening. Providing the mandrel in the expandable member may reduce the likelihood of the expandable member buckling and contacting the hollow moulded fibre product. By using the mandrel to perform the function of transitioning the expandable member from the normal configuration to the inverted configuration, an additional system within the expandable member may not be required to perform this function. This may increase the likelihood that the first portion may move into and / or through the second portion without widening the expandable member and thereby reduce the likelihood of the second portion rubbing along the hollow moulded fibre product when compared with providing a separate system to transition the expandable member between the configurations. Optionally, moving the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration comprises moving the point of attachment of the mandrel to the expandable member away from the opening. Optionally, the method comprises applying a further pressure to the inside of the expandable member whilst moving the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration; and the further pressure is greater than the ambient pressure on the outside of the expandable member. Using both the further pressure and the mandrel to transition the expandable member from the inverted to the normal configuration may reduce the time required to transition from the inverted to the normal configuration. This may increase the throughput of a manufacturing system employing the method when compared with using either the mandrel or the further pressure in isolation. Optionally, the mandrel comprises one or more holes through which a fluid is flowable from an interior of the mandrel to an exterior of the mandrel to expand the expandable member; and the method comprises introducing fluid into the expandable member via the mandrel to expand the expandable member. Optionally, the mandrel comprises an attachment mechanism for detachably attaching the mandrel to the first portion of the expandable member; and the method comprises performing at least one of a post-insertion operation and a pre-withdrawal operation; the post-insertion operation comprises, after inserting the expandable member, in the inverted configuration, into the hollow moulded fibre product: moving the point of attachment of the mandrel to the expandable member away from the opening to move the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration; and detaching the mandrel from the first portion; and the pre-withdrawal operation comprises, before withdrawing the expandable member, in the inverted configuration, from the hollow moulded fibre product: attaching the mandrel to the first portion; and moving the point of attachment of the mandrel to the expandable member towards the opening to move the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration. As a result, the first portion may be attached and detached from the mandrel to best suit the different stages of the method. For example, detaching the first portion from the mandrel after the expandable member has been inserted and moved to the normal configuration may enable the first portion to freely expand during the forming operation uninhibited by the mandrel. Uninhibited expansion of the expandable member may improve the magnitude and uniformity of a pressure applied by the expandable member to the hollow moulded fibre product Thereby, the quality of the hollow moulded fibre product may be improved due to improved compaction which may result from the improved magnitude and uniformity of the pressure applied. The first portion may then be reattached to enable the mandrel to invert the expandable member and withdraw the expandable member from the hollow moulded fibre product. Optionally, the mandrel comprises a first part and a second part; the method comprises expanding the expandable member; the second part of the mandrel is attached to the first portion of the expandable member during movement of the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration, and during expansion of the expandable member; and the method comprises moving the second part in response to expanding the expandable member. As a result, the expandable member may expand relatively uninhibited by the mandrel during the forming operation, whilst also being attached to the mandrel, which enables the mandrel to transition the expandable member between the normal configuration and the inverted configuration. Optionally, the method comprises: providing a mould; locating the hollow moulded fibre product within the mould; and performing at least one of a first operation and a second operation; wherein the first operation comprises: moving the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration after inserting the expandable member, in the inverted configuration, into the hollow moulded fibre product; and introducing fluid into the expandable member to expand the expandable member so as to urge the hollow moulded fibre product against an inner surface of the mould when the expandable member is in the normal configuration; and wherein the second operation comprises: introducing fluid into the expandable member to expand the expandable member so as to urge the hollow moulded fibre product against an inner surface of the mould; moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration after introducing fluid into the expandable member to expand the expandable member; and withdrawing the expandable member, in the inverted configuration, from the hollow moulded fibre product after moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration. As a result, a forming operation is applied to the hollow moulded fibre product. A forming operation may improve the mechanical and aesthetic properties of the hollow moulded fibre product. Optionally, the first operation and / or the second operation comprises applying heat to the hollow moulded fibre product. As a result, a thermoforming operation is applied to the hollow moulded fibre product. A thermoforming operation may improve the mechanical and aesthetic properties of the hollow moulded fibre product. Optionally, applying heat to the hollow moulded fibre product is performed during the introducing fluid into the expandable member to expand the expandable member. Optionally, after introducing fluid into the expandable member to expand the expandable member and applying heat to the hollow moulded fibre product, the product has a fluid content which is greater than 5% of the mass of the product. As a result, a greater amount of fluid from the hollow moulded fibre product may remain on the expandable member when compared with having a fluid content of less than 5%. A greater amount of fluid may act to lubricate the expandable member and thereby reduce the friction between the portions of the expandable member and / or the expandable member and the hollow moulded fibre product. The mass may be measured after introducing fluid into the expandable member to expand the expandable member and the applying heat to the hollow moulded fibre hollow moulded fibre product. Optionally, the hollow moulded fibre product comprises paper fibres. Using paper fibres may have environmental benefits, such as being recyclable. However, paper fibres may be more susceptible to damage from the insertion and the withdrawal of the expandable member than other materials, for example polypropylene. Therefore, inserting and / or withdrawing the expandable member in the inverted configuration may be particularly beneficial when the hollow moulded fibre product comprises paper pulp. According to a second aspect of the present invention, there is provided a mandrel system for use in processing a hollow moulded fibre product, the mandrel system comprising: a mandrel having an end attachable to a first portion of an expandable member; and a connector attachable to a second portion of the expandable member, the second portion defining an opening of the expandable member, wherein: the mandrel is moveable relative to the connector between a first position to a second position; when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. As a result, when the mandrel is attached to the first portion, and the connector is attached to the second portion, movement of the mandrel between the first position and the second position causes the expandable member to transition between a normal configuration and an inverted configuration in which at least one of: the first portion is located in the second portion, and the expandable member is inside out compared with the normal configuration. By the second value being no greater than 25% of the first value, a greater proportion of the first portion may be located in the second portion, or a greater proportion of the expandable member may be inside out when compared with a second value of greater than 25%. As described above, this may reduce the likelihood of the expandable member rubbing along the hollow moulded fibre product during the insertion and the withdrawal of the expandable member into and from the hollow moulded fibre product. Thereby, the likelihood of the expandable member becoming damaged and / or the hollow moulded fibre product becoming damaged due to the rubbing may be reduced. Optionally, the mandrel is moveable relative to the connector between at least one of the first position and the second position to a third position; and the third position is located on an opposite side of the connector to a side on which the first position and the second position are located. As a result, a greater proportion of the first portion may be located in the second portion or a greater proportion of the expandable member may be inside out when compared with omitting the third position. Optionally, when in the third position, the distance between the connector and the end of the mandrel has a third value which is no less than 75% of the first value. Optionally, the mandrel system comprises the expandable member. Optionally, the first portion of the expandable member has a width which is greater that a width of the second portion of the expandable member when the expandable member is in the normal configuration. Optionally, the mandrel system comprises a sleeve located in the second portion of the expandable member. Optionally, a Young’s modulus of the sleeve is greater than a Young’s modulus of the expandable member. Optionally, the expandable member comprises a wall thickness which is constant along a length of the expandable member. Optionally, the mandrel system comprises a pressurising system for applying a pressure to an inside of the expandable member, and a controller for causing the pressurising system to apply the pressure to the inside of the expandable member during movement of the mandrel from the first position to the second position. Optionally, the controller is for causing the pressurising system to apply the pressure to the inside of the expandable member during movement of the mandrel from at least one of the first position and the second position to the third position. Optionally, the pressure is no less than Ibar. Optionally, the pressure is no greater than 2b ar. Optionally, the controller is for causing the pressurising system to apply a further pressure to the inside of the expandable member during movement of the mandrel from the second position to the first position. Optionally, the controller is for causing the pressurising system to apply the further pressure to the inside of the expandable member during movement of the mandrel from the third position to at least one of the first position and the second position. Optionally, the mandrel comprises one or more holes through which a fluid is flowable from an interior of the mandrel to an exterior of the mandrel to expand the expandable member. Optionally, the mandrel comprises an attachment mechanism for detachably attaching the mandrel to the first portion of the expandable member, and the attachment mechanism is configured to detach the mandrel from the first portion in response to expansion of the expandable member. Optionally, the mandrel comprises a first part and a second part; the second part of the mandrel is attached to the first portion of the expandable member; and the second part is free to move in response to expansion of the expandable member. According to a third aspect of the present invention, there is provided a mould system for processing a hollow moulded fibre product, the mould system comprising: the mandrel system, and a mould for receiving the hollow moulded fibre product, wherein the mandrel system is insertable into and withdrawable from the mould, and usable with the mould to process the hollow moulded fibre product. Optionally, the mould system comprises a pump for introducing fluid into the expandable member to expand the expandable member so as to urge the hollow moulded fibre product against an inner surface of the mould. The pump may comprise the pressurising system. Optionally, the mould system comprises a heater for applying heat to the hollow moulded fibre product during the introduction of fluid into the expandable member. Optionally, the mould system is a paper pulp mould system. According to a fourth aspect of the present invention, there is provided a mandrel system control system configured to cause a mandrel system to: move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member between a first position to a second position, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. According to a fifth aspect of the present invention, there is provided a non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a mandrel system control system, cause a mandrel system to: move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member between a first position to a second position, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. According to a sixth aspect of the present invention, there is provided a mould system control system configured to cause a mould system to: move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member from a first position to a second position; and at least one of: insert the mandrel, with the mandrel in the second position relative to the connector, into a mould of the mould system; and withdraw the mandrel, with the mandrel in the second position relative to the connector, from the mould, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. According to a seventh aspect of the present invention, there is provided a non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a mould system control system, cause a mould system to: move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member from a first position to a second position; and at least one of: insert the mandrel, with the mandrel in the second position relative to the connector, into a mould of the mould system; and withdraw the mandrel, with the mandrel in the second position relative to the connector, from the mould, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. According to an eight aspect of the present invention, there is provided a mandrel system control system configured to cause a mandrel system to move a first portion of an expandable member towards an opening of the expandable member to transition the expandable member from a normal configuration to an inverted configuration in which at least one of: the first portion is located in a second portion of the expandable member, and the expandable member is inside out compared with the normal configuration. According to a ninth aspect of the present invention, there is provided a non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a mandrel system control system, cause a mandrel system to move a first portion of an expandable member towards an opening of the expandable member to transition the expandable member from a normal configuration to an inverted configuration in which at least one of: the first portion is located in a second portion of the expandable member, and the expandable member is inside out compared with the normal configuration. According to a tenth aspect of the present invention, there is provided a mould system control system configured to cause a mould system to: move a first portion of an expandable member towards an opening of the expandable member to transition the expandable member from a normal configuration to an inverted configuration in which at least one of: the first portion is located in a second portion of the expandable member, and the expandable member is inside out compared with the normal configuration; and at least one of: insert the expandable member, in the inverted configuration, into a mould of the mould system; and withdraw the expandable member, in the inverted configuration, from the mould. According to a eleventh aspect of the present invention, there is provided a non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a mould system control system, cause a mould system to: move a first portion of an expandable member towards an opening of the expandable member to transition the expandable member from a normal configuration to an inverted configuration in which at least one of: the first portion is located in a second portion of the expandable member, and the expandable member is inside out compared with the normal configuration; and at least one of: insert the expandable member, in the inverted configuration, into a mould of the mould system; and withdraw the expandable member, in the inverted configuration, from the mould. In some examples of any of the above aspects, the hollow moulded fibre product is a necked hollow moulded fibre product, such as a bottle, a jar or a type of vase. In some examples of any of the above aspects, the hollow moulded fibre product is a bottle. According to a twelfth aspect of the present invention, there is provided a receptacle manufacturing line comprising the mould system for processing the hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle. The apparatus may comprise an interior coater and the at least one additional process may comprise the interior coater coating at least a portion of an interior of the hollow moulded fibre product to produce an internally coated hollow moulded fibre product. The apparatus may comprise a closure-part applicator and the at least one additional process may comprise the closure-part applicator applying a closure part to the product or the internally coated hollow moulded fibre product to produce a closable or closed hollow moulded fibre product. The apparatus may comprise an exterior coater and the at least one additional process may comprise the exterior coater coating at least a portion of an exterior of the hollow moulded fibre product or the internally coated hollow moulded fibre product or the closable or closed hollow moulded fibre product to produce an externally coated hollow moulded fibre product. The apparatus may comprise a decorator and the at least one additional process may comprise the decorator decorating the hollow moulded fibre product or the internally coated hollow moulded fibre product or the closable or closed hollow moulded fibre product or the externally coated hollow moulded fibre product to produce a decorated hollow moulded fibre product. The apparatus may comprise a dryer and the at least one additional process may comprise the dryer drying the hollow moulded fibre product or the internally coated hollow moulded fibre product or the closable or closed hollow moulded fibre product or the externally coated hollow moulded fibre product or the decorated hollow moulded fibre product to produce a dried hollow moulded fibre product. The apparatus may comprise an evaluator and the at least one additional process may comprise the evaluator evaluating the hollow moulded fibre product, the internally coated hollow moulded fibre product, the closable or closed hollow moulded fibre product, the externally coated hollow moulded fibre product, the decorated hollow moulded fibre product, or the dried hollow moulded fibre product to produce an evaluated hollow moulded fibre product. In some examples, the receptacle is the hollow moulded fibre product, the internally coated hollow moulded fibre product, the closable or closed hollow moulded fibre product, the externally coated hollow moulded fibre product, the decorated hollow moulded fibre product, the dried hollow moulded fibre product, or the evaluated hollow moulded fibre product. In some examples, the receptacle is a necked receptacle, such as a bottle, jar or a type of vase, and the receptacle manufacturing line is a necked-receptacle manufacturing line. In some examples, the receptacle is a bottle. According to a thirteenth aspect of the present invention, there is provided a method of manufacturing a receptacle, the method comprising performing the method according to the first aspect of the present invention, and then performing at least one additional process on the hollow moulded fibre product to provide the receptacle The at least one additional process may comprise coating at least a portion of an interior of the hollow moulded fibre product to produce an internally coated hollow moulded fibre product. The at least one additional process may comprise applying a closure part to the hollow moulded fibre product or the internally coated hollow moulded fibre product to produce a closable or closed hollow moulded fibre product. The at least one additional process may comprise coating at least a portion of an exterior of the hollow moulded fibre product or the internally coated hollow moulded fibre product or the closable or closed hollow moulded fibre product to produce an externally coated hollow moulded fibre product. The at least one additional process may comprise decorating the hollow moulded fibre product or the internally coated hollow moulded fibre product or the closable or closed hollow moulded fibre product or the externally coated hollow moulded fibre product to produce a decorated hollow moulded fibre product. The at least one additional process may comprise drying the hollow moulded fibre product or the internally coated hollow moulded fibre product or the closable or closed hollow moulded fibre product or the externally coated hollow moulded fibre product or the decorated hollow moulded fibre product to produce a dried hollow moulded fibre product. The at least one additional process may comprise evaluating the hollow moulded fibre product, the internally coated hollow moulded fibre product, the closable or closed hollow moulded fibre product, the externally coated hollow moulded fibre product, the decorated hollow moulded fibre product, or the dried hollow moulded fibre product to produce an evaluated hollow moulded fibre product. In some examples, the receptacle is the hollow moulded fibre product, the internally coated hollow moulded fibre product, the closable or closed hollow moulded fibre product, the externally coated hollow moulded fibre product, the decorated hollow moulded fibre product, the dried hollow moulded fibre product, or the evaluated hollow moulded fibre product. In some examples, the receptacle is a necked receptacle, such as a bottle, jar or a type of vase. In some examples, the receptacle is a bottle. According to a fourteenth aspect of the present invention, there is provided a method of providing a content-containing receptacle, the method comprising providing a receptacle obtained by the method according to the thirteenth aspect of the present invention and providing the contents in the receptacle to provide the content-containing receptacle. In some examples, the providing the contents in the receptacle comprises putting the contents into the receptacle. In contrast, in some examples, the providing the receptacle comprises providing the receptacle with the contents already present in the receptacle, thereby providing the contents in the receptacle. The contents may be in the form of, for example, a liquid, a powder, other flowable materials, one or more solid objects, or a combination thereof. For example, the contents may be a foodstuff such as a condiment, a beverage such as an alcoholic beverage, a household care hollow moulded fibre product such as a detergent or other cleaning hollow moulded fibre product, a personal care hollow moulded fibre product such as a hair care hollow moulded fibre product or a personal cleansing hollow moulded fibre product or a healthcare hollow moulded fibre product or a pharmaceutical hollow moulded fibre product or a cosmetics hollow moulded fibre product, a fragrance hollow moulded fibre product such as a perfume, a vehicle hollow moulded fibre product such as motor oil, or an industrial hollow moulded fibre product. Other suitable contents will be apparent to the skilled reader in view of the content of this application and their common general knowledge. In some examples, the receptacle is a necked receptacle, such as a bottle, a jar or a type of vase. In some examples, the receptacle is a bottle. Optionally, the method comprises: closing an opening of the receptacle after the providing contents in the receptacle, and / or applying a label or indicia to the receptacle. In some examples, the closing comprises applying a closure (such as a lid or a cap or a heat seal) to the receptacle to close the opening. In some examples, the closing comprises applying a heat seal to the receptacle and (e.g., thereafter) applying a lid or a cap to the receptacle. In some examples, the applying the label or indicia to the receptacle occurs after the providing the contents in the receptacle (that is, the label or indicia is applied to the content-containing receptacle). In other examples, the applying the label or indicia to the receptacle occurs before or during the providing the contents in the receptacle. In some examples, the applying occurs before the closing. In some examples, the applying occurs after the closing. In some examples, the applying occurs during the closing. According to a fifteenth aspect of the present invention, there is provided use of a receptacle obtained by the method according to the fourteenth aspect of the present invention to contain contents. The use could be, for example, by a person (such as a natural person or a company) who puts the contents into the receptacle, or by a person who transports the contents, or by a person who wishes to dispose of (e.g., to a consumer or end user), offer to dispose of (e.g., to a consumer or end user), import, or keep the contents whether for disposal or otherwise. The contents may, for example, be in the form of any of those discussed above. In some examples, the receptacle is a necked receptacle, such as a bottle, a jar or a type of vase. In some examples, the receptacle is a bottle. It will be appreciated that optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate. BRIEF DESCRIPTION OF DRAWINGS Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of an example receptacle manufacturing line for performing a method of manufacturing receptacles from paper pulp; Figure 2 is a cross-sectional view of an example mould system; Figure 3 is a cross-sectional view of a mandrel system of the example mould system; Figure 4 is a cross-sectional view of an expandable member of the mandrel system; Figure 5 is an expanded view of part of Figure 4; Figure 6 is a cross-sectional view of a sleeve of the mandrel system; Figures 7a-7d show, by way of cross-sectional views, different stages in the transition of the expandable member from a normal to an inverted configuration; Figure 8a-8e show, by way of cross-sectional views, different stages in the operation of the example mould system; Figure 9 shows a cross-sectional view of the expandable member in an alternative inverted configuration; Figure 10a shows a non-transitory computer-readable storage medium according to an example; Figure 10b shows an alternative non-transitory computer-readable storage medium according to an example; Figure 11 shows an example method of providing a content-containing receptacle; Figure 12 shows a schematic cross-sectional view of a receptacle containing contents, according to an example; and Figure 13 shows an example method of providing a content-containing receptacle. DETAILED DESCRIPTION The following description presents exemplary embodiments and, together with the drawings, serves to explain principles of embodiments of the invention. Figure 1 shows a receptacle manufacturing line for performing a method of manufacturing receptacles, in this case necked receptacles, and more specifically in this case in the form of bottles, from paper pulp (i.e., which can form the basis of an example fibre suspension). By “necked receptacle” it is meant that the receptacle has an internal narrowing, or “neck”, between a main body portion, in which most of or all the contents of the receptacle are stored in use, and an opening through which the contents can enter or leave the receptacle in use. The internal width of the receptacle at the neck may be the same as or different to the internal width of the opening. However, the internal width of the neck is smaller than that of the main body portion, so that a shoulder is defined by and between the neck and the main body portion. This shoulder complicates manufacture of the receptacle, since it interferes with subsequent removal (and, in some cases, insertion) of whatever mould tool is inserted into the receptacle to form the internal shape of the receptacle. Examples of necked receptacles are bottles, jars, and certain types of vases. The process is merely exemplary and is provided to give context to examples of the present invention. It will be appreciated that, in other examples, the receptacle manufacturing line could be for making non-necked receptacles (i.e., receptacles without such a neck), such as bowls or trays. Broadly speaking, the exemplary process comprises providing a fibre suspension, introducing the fibre suspension into a mould cavity of a porous first mould and expelling a liquid (such as water) from the fibre suspension to produce a hollow moulded fibre product (which may be called a wet precursor or embryo) in the mould cavity, further moulding the hollow moulded fibre product to produce a hollow further-moulded fibre product, drying and then internally-coating the hollow further-moulded fibre product to produce an internally coated product, drying the internally coated product to produce a dried product, applying a closure part to the dried product to produce a closable or closed product, externally-coating and / or decorating the closable or closed product to produce an externally coated and / or decorated product, and then drying the externally coated or decorated product to produce another dried product. As will be apparent at least from the following description, modifications may be made to the exemplary process to provide variants thereof in which other examples of the present invention may be embodied. For example, in some cases, either the internal coating or the external coating and / or decorating may be omitted. Moreover, in the present case and as indicated by the stars labelled Ins. 1 to Ins. 5 in Figure 1, the process comprises inspecting or evaluating the hollow further-moulded fibre product, the internally coated product, the closable or closed product, the externally coated or decorated product, and the dried product to produce respective evaluated products. In some examples, the receptacle is the hollow moulded fibre product, the hollow further-moulded fibre product, the internally coated product, the closable or closed product, the externally coated or decorated product, one of the dried products, or one of the respective evaluated products. In this example, providing the fibre suspension comprises preparing the fibre suspension from ingredients thereof. More specifically, the preparing comprises providing pulp fibres, such as paper pulp fibres, and mixing the pulp fibres with a liquid to provide hydrated pulp fibres. In this example, the pulp fibres are provided in sheet form from a supplier and the liquid comprises water and one or more additives. In this example, the liquid is mixed with the pulp fibres to provide hydrated pulp fibres having a solid fibres content of lwt% to 5wt% (by dry mass of fibres). In examples, the one or more additives includes a sizing agent, such as alkylketene dimer (AKD). The hydrated pulp fibres typically comprise AKD in an amount of 0.4wt% with respect to the total dry mass of the solid fibres in the hydrated pulp fibres. In some examples, one or more additives are present in the liquid at the point of mixing the pulp fibres with the liquid. In some examples, one or more additives are included in the hydrated pulp fibres after mixing the pulp fibres with the liquid (for example, the pulp fibres are hydrated for a period of time, such as from 2 to 16 hours, and then one or more additives are supplied to the hydrated pulp fibres). The hydrated pulp fibres are passed between plates of a valley beater 11 or refiner that are in motion relative to each other. This fibrillates some, or all, of the fibres, meaning that cell walls of those fibres are caused to become partially delaminated so that wetted surfaces of those fibres comprise protruding hairs or fibrillations. These fibrillations will help to increase a strength of bonds between the fibres in the dried end product. In other examples, the valley beater 11 or refiner may be omitted. The resultant processed pulp is stored in a vat 12 in a relatively concentrated form (for example, a solid fibres content of 1 wt% to 5wt%) to reduce a required storage space. At an appropriate time, the processed pulp is transferred to a mixing station 13 at which the processed pulp is diluted in further water and, optionally, mixed with one or more additives (as well as, or in place of, the one or more additives provided with the hydrated pulp fibres) to provide the fibre suspension ready for moulding. In this example, the solid fibres account for 0.7wt% of the resultant fibre suspension (by dry weight of fibres), but in other examples the proportion of solid fibres in the fibre suspension may be different, such as another value in the range of 0.5wt% to 5wt%, or 0.1wt% to lwt%, of the fibre suspension (by dry weight of fibres). In some examples, the one or more additives mixed with the processed pulp and water includes a dewatering agent, such as modified and / or unmodified polyethylene imine (PEI), for example modified PEI sold under the trade name Polymin® SK. In some examples, the one or more additives are mixed with the water, and the water and one or more additives subsequently mixed with the processed pulp; in other examples, the processed pulp and water are mixed, and the one or more additives subsequently mixed with the processed pulp and water. The fibre suspension typically comprises Polymin® SK in an amount of 0.3wt% with respect to the total dry mass of the solid fibres. Mixing of the fibre suspension at the mixing station 13 helps to homogenise the fibre suspension. In other examples, the processed pulp or the fibre suspension may be provided in other ways, such as being supplied ready-made. Downstream of the vat 12 and the mixing station 13 is a first moulding station that comprises a porous first mould 15. In this example, the porous first mould 15 comprises two half-moulds 14 that are movable towards and away from each other, in this case using a hydraulic ram. In this example, each of the half-moulds 14 is a monolithic or unitary tool formed by additive manufacturing (for example, 3D-printing) that defines a mould profile, and, when the half-moulds 14 are brought into contact with each other, their respective mould profiles cooperate to define the mould cavity in which the hollow moulded fibre product is to be formed. Each half-mould 14 itself defines a smaller moulding cavity and, when brought into cooperation with a second half-mould 14, the smaller moulding cavities combine to provide the overall mould cavity. The two halfmoulds 14 may themselves be considered “splits” or “moulds” and the overall porous first mould 15 may be considered a “split-mould” or, again, a “mould”. In other examples, the porous first mould 15 may comprise more than two splits 14, such as three, four or six splits, that cooperate to define the moulding cavity. In Figure 1, the fibre suspension (also known as slurry) is top-filled into the porous first mould 15, in contrast to moulding processes that dip a mould in slurry. The fibre suspension is drawn under vacuum via a line 16 and into the porous first mould 15, with excess suspending liquid being drawn through the porous first mould 15 under vacuum via a line 18 into a tank 17. Shot mass may be controlled by measuring (for example, weighing) the amount of liquid drawn into the tank 17. A weight scale platform supporting the tank 17 is visible in Figure 1. Once a required amount (for example, a predetermined volume, such as 10 litres, or a predetermined mass, such as 10 kilograms) of liquid has been collected in the tank 17, suction of the suspending liquid through the porous first mould 15 is stopped and the first mould 15 is opened to ambient air. In this example, the suspending liquid drawn with the fibre suspension in line 16 is water, or predominantly water (as additives may also be present). The liquid drawn under vacuum via the line 18 and into the tank 17 is substantially free of fibres, since these are left behind against the walls of the porous first mould 15 to form the hollow moulded fibre product. In one example, in order to remove further suspending liquid (for example, water) from the hollow moulded fibre product, and form or consolidate the three-dimensional shape of the product, high pressure fluid (such as compressed air) is introduced into the first mould 15 to compress the fibre suspension against the cavity wall of the first mould 15. This process strengthens the product so that it can be handled, and displaces water from in between the fibres, thereby increasing the efficiency of a subsequent drying process. The fluid is regulated using a hydraulic pump 20. The pump 20 has a cylinder that displaces the fluid in a line 21 into the first mould 15. In an alternative example, an impermeable inflation element in the form of a collapsible bladder is inserted into the first mould 15 and expanded, by introduction of a fluid into the bladder from the line 21, to act as an internal high-pressure core structure for the first mould 15. In such an alternative, the fluid within the line 21 is preferably non-compressible, such as water or oil, although in other examples it could be a compressible fluid, such as air. Water has the advantage over other non-compressible liquids that any leaking or bursting of the bladder will not introduce a new substance to the system (since the suspending liquid is already water, or predominantly water). Demoulding occurs when the first mould 15 opens for removal of the self-supporting hollow moulded fibre product 22. Mould cleaning 23 is preferably performed subsequently, to remove any remaining small fibres and / or other debris and maintain a porosity of the porous first mould 15. In this example, a radially firing high-pressure jet is inserted into the mould cavity while the first mould 15 is open. This dislodges debris from the wall of the mould cavity. Alternatively, or in addition, water from the tank 17 is pressurised through the back of the porous first mould 15 to dislodge entrapped fibres and / or other debris. Water is drained for recycling back to an upstream part of the system. It is noteworthy that cleaning is important for conditioning the first mould 15 for re-use. The first mould 15 may appear visibly clean after removal of the receptacle, but its performance could be compromised without cleaning. According to Figure 1, the hollow moulded fibre product 22 is subsequently transported to a second moulding station where, in a, for example, aluminium, mould 25, pressure and heat are applied for thermoforming a desired neck and surface finish, optionally including embossed and / or debossed surface features. After two halves of the mould 25 have closed around the product 22, a pressuriser is engaged. For example, a bladder 26 (for example, a thermoforming bladder 26) is inserted into the product 22. The bladder 26 is inflated with a pressurised fluid supplied via a line 27 by a pump 28 . The pressurised fluid is preferably a non-compressible fluid such as water or oil, although in other examples it could be a compressible fluid such as air. In other examples, during supply, the pressurised fluid is heated with, for example, a heater or, alternatively, is cooled with, for example, a heat exchanger. An external mould block 24 of the mould 25, and / or the mould 25 itself, is also, or alternatively, heated in some examples. After thermoforming, a state of the product 22, which may now be considered a hollow further-moulded fibre product, is considerably more rigid, with more compressed side walls, as compared with the state of the product 22 at demoulding from the first mould 15. A drying stage 30 (for example, a microwave drying process or other drying process) is performed on the product 22 downstream of the thermoforming, as shown, to provide a dried product. In one example, the drying stage 30 is performed before thermoforming to provide a dried product. However, moulding in the mould 25 requires some water content to assist with bonding during the compression process. The drying may be performed using a dryer, such as a machine that acts to cause drying of the product or simply a shelf or other support on which the product 22 rests while drying. The product 22 is then subjected to an internal-coating stage during which, in this example, an interior coater in the form of a spray lance 31 is inserted into the product 22 and applies one or more surface coatings to internal walls of the product 22 to produce an internally coated product. In another example, the product 22 is instead filled with and subsequently drained of a liquid that coats the internal walls of the product 22. In practice, such coatings provide a protective layer to prevent egress of contents into the bottle wall, which may permeate and / or weaken it. Coatings will be selected dependent on the intended contents of finished receptacle, for example, a beverage, foodstuff, detergent, lubricant, pharmaceutical product, etc. In this example, the internally coated product 22 is then subjected to a curing or drying process 32, which can be configured or optimised dependent on the internal coating, for example, drying for twenty-four hours at ambient conditions or by a flash drying method. The drying again may be performed using a dryer, such as a machine that acts to cause drying of the product or simply a shelf or other support on which the product 22 rests while drying. Following the drying, the coated product 22 is considered another dried product. A closure or mouth forming process is then performed on the product 22 by a closure-part applicator to produce a closable or closed product. For example, as shown in Figure 1, a neck fitment 33 is affixed to the dried product. This results in the product being closable subsequently by positioning of a cap, lid or other closure relative to the neck fitment. An exterior coating and / or decoration is then applied to the product 22 by an exterior coater and / or a decorator, respectively, as shown in the further stage 34, to produce an externally coated and / or decorated product. In one example, the product 22 is dipped into a liquid to coat its outer surface, as shown in Figure 1. In another example, the outer surface receives the external coating in a different manner. The coating and / or decoration may cover all or only part of an external surface of the product. The product 22 is then allowed to dry in warm air to produce another dried product. In other examples, the drying may be performed using a dryer such as one of those discussed above. The product 22 may therefore be fully formed, considered the end “receptacle”, and ready to accept contents therein. In other examples, the receptacle may be fully formed without the neck fitment 35 being affixed and / or without the interior coating being applied and / or without the exterior coating being applied and / or without the decoration being applied and / or immediately after one of the drying processes or one of the inspecting and / or evaluating processes. For example, in some cases, the product is provided with the closure part by moulding the closure part during moulding of the product at the first moulding station and / or the second moulding station. Figure 2 shows a mould system 101 which may be used to thermoform the product 22 discussed above. The mould system 101 comprises a mould 103, a mandrel system 105, a pump 107, and a line 109. The mould 103 comprises a first part 111, and a second part 113. In other examples, the mould 103 may comprise more than two parts. The two parts 111,113 are separable so as to open the mould 103. Each part 111,113 comprises a cavity 115 and a heater 117 for heating a respective part 111,113 of the mould 103. When the two parts 111,113 are brought together to close the mould 103, a mould cavity 119 is created within the mould 103 that comprises the cavities 115 of the first part 111 and the second part 113. In this particular example, the mould cavity 119 has the shape of a bottle. The mould 103 comprises an opening 121 to the mould cavity 119. The mandrel system 105 (shown in isolation in Figure 3) comprises a connector 123, a mandrel 125, an expandable member 127, an attachment mechanism 129, a sleeve 131, and a controller 133. The connector 123 comprises a bore 137 that extends through the connector 123 from a top 120 to a bottom 122 of the connector 123. The mandrel 125 comprises a cylindrical tube 139. A plurality of holes 140 are formed along the length of the tube 139. The holes 140 are located along a lower portion of the tube 139 and extend radially through the tube 139 to allow fluid to flow from the interior of the mandrel 125 to the exterior of the mandrel 125. The mandrel 125 extends through the bore 137 in the connector 123 and into the expandable member 127 such that a lower portion of the mandrel 125 is located within the expandable member 127. The upper portion of the mandrel 125 is connected to the line 109. The mandrel 125 is free to move relative to the connector 123. In particular, the mandrel 125 is free to move up and down within the bore 137. The expandable member 127 (shown in isolation in Figure 4 in a normal configuration, which is described below in more detail) is a one-piece construction and is formed of silicone having a hardness of 40 Shore A. The expandable member 127 comprises a neck portion 141, a shoulder portion 143, and a main body portion 145. The main body portion 145 of the expandable member 127 may be considered a first portion of the expandable member 127. The neck portion 141 of the expandable member 127 may be considered a second portion of the expandable member 127. The neck portion 141 of the expandable member 127 comprises a funnel region 147 and a cylindrical region 149. The funnel region 147 has a frustoconical shape and defines an opening 151 to the interior of the expandable member 127. A wider end 153 of the funnel region 147 is connected to the connector 123, and a narrower end 155 of the funnel region 147 meets the cylindrical region 149. The cylindrical region 149 of the neck portion 141 of the expandable member 127 has a width 161 (measured between two opposing, diametrically opposite, points on an outer surface of the cylindrical region 149 of the neck portion 141 of the expandable member 127) of 29mm when the expandable member 127 is in the normal configuration (described below) and an inverted configuration (described below). The shoulder portion 143 of the expandable member 127 tapers outwardly from the cylindrical region 149 of the neck portion 141. A narrower end 163 of the shoulder portion 143 of the expandable member 127 meets the cylindrical region 149 of the neck portion 141 of the expandable member 127, and a wider end 165 of the shoulder portion 143 of the expandable member 127 meets the main body portion 145 of the expandable member 127. The main body portion 145 of the expandable member 127 has a cylindrical shape which is closed at one end by a bottom 167 of the main body portion 145. The main body portion 145 of the expandable member 127 has a width 169 (measured between two opposing, diametrically opposite, points on an outer surface of the main body portion 145 of the expandable member 127) of 44mm when the expandable member 127 is in the normal configuration. The attachment mechanism 129 (an expanded view of which is shown in Figure 5) comprises a plug 171 and a socket 173. The plug 171 is located at a lower end 181 of the mandrel 125, i.e., the end of the mandrel 125 located within the expandable member 127. The socket 173 is attached to the bottom 167 of the main body portion 145 of the expandable member 127. The socket 173 cooperates with the plug 171 to detachably attach the main body portion 145 of the expandable member 127 to the mandrel 125. Thereby the lower end 181 of the mandrel 125 may be considered the point of attachment of the mandrel 125 to the expandable member 127. The sleeve 131 (shown in isolation in Figure 6) comprises a cylindrical portion 183 and a funnel portion 185. The cylindrical portion 183 of the sleeve 131 has a cylindrical shape and is located in the cylindrical region 149 of the neck portion 141 of the expandable member 127. The cylindrical portion 183 of the sleeve 131 has a width 187 (measured between two opposing, diametrically opposite, points on an inner surface of the cylindrical portion 183 of the sleeve 131) of 29mm. The funnel portion 185 of the sleeve 131 has a frustoconical shape and meets the cylindrical portion 183 of the sleeve 131 at one end 189 and the connector 123 at another end 191. The funnel portion of the sleeve 131 is located in the funnel region 147 of the neck portion 141 of the expandable member 127. The sleeve 131 is formed of polytetrafluoroethylene (PTFE) and has a Young’s Modulus of 575MPa, which is greater than the Young’s Modulus of the expandable member 127. The coefficient of friction between the silicone of the expandable member 127 and the PTFE of the sleeve 131 is 0.6, which is less than the coefficient of friction between the silicone of the expandable member 127 and itself, which is 1.15. Thereby, the coefficient of friction between the cylindrical portion 183 of the sleeve 131 and the main body portion 145 of the expandable member 127 is less than the coefficient of friction between the neck portion 141 of the expandable member 127 and the main body portion 145 of the expandable member 127. The controller 133 controls the operation of an actuator 142 which moves the mandrel 125 relative to the connector 123. The controller 133 also controls the pump 107 and a robotic arm (not shown), which moves the connector 123 relative to the mould 103. The pump 107 comprises a cylinder which displaces a fluid in the line 109. In some examples, the fluid is one of air, water, or oil. As the line 109 is connected to the mandrel 125, displacing the fluid causes the pump 107 to supply a pressurised fluid to the interior of the mandrel 125. The pressurised fluid then flows through the holes 140 in the mandrel 125 and into the expandable member 127. Thereby, the pump 107 is used to expand the expandable member 127. The pump 107 is also capable of operating in the opposite direction to withdraw the fluid from the expandable member 127 and thereby collapse and contract the expandable member 127. Transitioning of the expandable member 127 between a normal configuration and an inverted configuration will now be described with reference to Figures 7a to 7d. It should be noted that Figures 7a to 7d show the transitioning of the expandable member 127 when the expandable member 127 is external to the product 22. Figure 7a shows the expandable member 127 in the normal configuration. At this stage, the lower end 181 of the mandrel 125 is in a first position at a distance 201 of 250mm from the bottom 122 of the connector 123 and is on a first side 203 of the connector 123. The lower end 181 of the mandrel 125 is attached to the main body portion 145 of the expandable member 127 by the attachment mechanism 129. The normal configuration is the configuration of the expandable member 127 immediately prior to expansion of the expandable member 127 to apply a forming operation to the product 22, as described in more detail below with reference to Figure 8c. Turning now to Figure 7b, the controller 133 controls the actuator 142 to move the lower end 181 of the mandrel 125 in a first direction 205 towards the bottom 122 of the connector 123. As the lower end 181 of the mandrel 125 is attached to the main body portion 145 of the expandable member 127 by the attachment mechanism 129, the movement of the lower end 181 of the mandrel 125 causes the main body portion 145 of the expandable member 127 to move towards the bottom 122 of the connector 123 and towards the opening 121 of the expandable member 127. At the same time, the controller 133 controls the pump 107 to supply the pressurised fluid to the mandrel 125 which flows through the holes 140 in the mandrel 125 and into the expandable member 127. This applies a pressure of 1.5bar to the inside of the expandable member 127. Applying pressures of no less than Ibar and no greater than 2 bar also envisaged. In some examples, the mandrel system 105 comprises a pressure relief valve which is used so that a constant pressure is maintained despite the reduction in volume as the expandable member is transitioned to the inverted configuration. The controller 133 continues to move the lower end 181 of the mandrel 125 in the first direction 205 which causes the main body portion 145 of the expandable member 127 to pass into and through the cylindrical portion 183 of the sleeve 131 and thereby into and through the cylindrical region 149 of the neck portion 141 of the expandable member 127. Figure 7c shows the expandable member 127 in a partially inverted configuration in which the lower end 181 of the mandrel 125 is in a second position at a distance 207 of 50mm from the bottom 122 of the connector 123 and is on the first side 203 of the connector 123. As the main body portion 145 of the expandable member 127 passes through the cylindrical portion 183 of the sleeve 131, a width 209 of the part of the main body portion 145 moving through the cylindrical portion 183 of the sleeve 131 is constrained by the cylindrical portion 183 of the sleeve 131. Thereby, the width 209 of the part of the main body portion 145 moving through the cylindrical portion 183 of the sleeve 131 is constrained to be less than the width 187 of the cylindrical portion 183 of the sleeve 131 and thereby less than the width 161 of the cylindrical region 149 of the neck portion 141 of the expandable member 127. The controller 133 continues to control the actuator 142 to move the lower end 181 of the mandrel 125 in the first direction 205 towards the bottom 122 of the connector 123 until the lower end 181 of the mandrel 125 is level with the bottom 122 of the connector 123. The controller 133 then continues to move the lower end 181 of the mandrel 125 in the first direction 205, which results in the lower end 181 of the mandrel 125 being on a second side 211 of the connector 123 and moving away from the connector 123. The controller 133 continues to control the actuator 142 to move the lower end 181 of the mandrel 125 in the first direction 205 until the lower end 181 of the mandrel 125 is in a third position at a distance 213 of 100mm from the top 120 of the connector 123. At this point (shown in Figure 7d), the expandable member 127 is in the inverted configuration. In the inverted configuration shown in Figure 7d, a first region 215 of the main body portion 145 of the expandable member 127 has moved through the sleeve 131 and is located on the second side 211 of the connect. A second region 217 of the main body portion 145 of the expandable member 127, which comprises approximately 40% of the length of the main body portion 145 of the expandable member 127, is located within the cylindrical portion 183 of the sleeve 131. The second region 217 of the main body portion 145 of the expandable member 127 comprising no less than 10% of the length of the main body portion 145 of the expandable member 127 is also envisaged. The second region 217 of the main body portion 145 of the expandable member 127 is constrained by the cylindrical portion 183 of the sleeve 131 such that the width 218 of the second region 217 of the main body portion 145 of the expandable member 127 is 27mm. Thereby, the width 218 of the second region 217 of the main body portion 145 of the expandable member 127 is 93% of the width 161 of the cylindrical region 149 of the neck portion 141 of the expandable member 127. The width 218 of the second part of the main body portion 145 of the expandable member 127 being no greater than 95% of the width 161 of the cylindrical region 149 of the neck portion 141 of the expandable member 127 is also envisaged. To transition from the inverted configuration to the normal configuration, the above steps described with reference to Figures 7a to 7d are reversed. Specifically, the controller 133 controls the actuator 142 to move the lower end 181 of the mandrel 125 in a second direction 221, towards the connector 123 until the lower end 181 of the mandrel 125 is level with the connector 123. Then the controller 133 controls the actuator 142 to continue to move the lower end 181 of the mandrel 125 in the second direction 211 such that the controller 133 is on the first side 203 of the connector 123 and moves away from the connector 123 (and thereby moves away from the opening 137 to the interior of the expandable member 127). This movement results in the first region 215 of the main body portion 145 of the expandable member 127 moving from the second side 211 of the connector 123, through the sleeve 131, and to the first side 203 of the connector 123. Similarly, this movement results in the second region 217 of the main body portion 145 of the expandable member 127 moving from being located inside the sleeve 131 to being located on the first side 203 of the connector 123. Use of the mould system 101 will now be provided by way of Figures 8a to 8e. As shown in Figure 8a, the two parts 111,113 of the mould 103 are closed around a product 22 such that the product 22 is located inside the mould cavity 119. The product 22 has the shape of a bottle and comprises a neck 301 and a main body 303. The neck 301 of the product 22 has a width 305 (measured between two opposing, diametrically opposite, points on an inner surface of the neck 301 of the product 22) of 34mm. The main body 303 of the product 22 has a width 307 (measured between two opposing, diametrically opposite, points on an inner surface of the main body 303 of the product 22) of 70mm. Therefore, the width 307 of the main body 303 of the product 22 is greater than the width 305 of the neck 301 of the product 22. The width 161 of the cylindrical region 149 of the neck 141 of the expandable member 127 is less than, and 85% of, the width 305 of the neck 301 of the product 22 when the expandable member 127 is in the normal configuration and the inverted configuration. Additionally, the width 305 of the neck 301 of the product 22 is less than the width 169 of the main body portion 145 of the expandable member 127 when the expandable member 127 is in the normal configuration. At the stage shown in Figure 8a, the mandrel system 105 is located outside of the mould cavity 119. The plug 171 is located within the socket 173 such that the expandable member 127 is attached to the lower end 181 of the mandrel 125. The expandable member 127 is in the inverted configuration described above with reference to Figure 3d. The controller 133 controls the heaters 117 to commence heating of the parts 111,113 of the mould 103. Turning now to Figure 8b, the controller 133 controls the robotic arm to move the mandrel system 105 down until the connector 123 contacts and connects with the top of the mould 103 and the mandrel system 105 extends into the product 22. Figure 8b shows how, when the expandable member 127 is in the inverted configuration, the width 218 of the first region 215 of the main body 125 of the expandable member 127 (which is located in the cylindrical portion 183 of the sleeve 131) is constrained by the cylindrical portion 183 of the sleeve 131 to be less than the width 305 of the neck 301 of the product 22. Thereby, the second region 217 of the main body 125 of the expandable member 127 may be inserted into the product 22 without contacting the neck 301 of the product 22. The controller 133 then controls the actuator 142 to move the lower end 181 of the mandrel 125 away from the connector 123 in the second direction 221 and thereby transition the expandable member 127 from the inverted configuration to the normal configuration as described with reference to Figs 7a to 7d. Simultaneously, the controller 133 controls the pump 107 to apply the pressure of 1,5bar to the inside of the expandable member 127. As the second region 217 and then the first region 215 of the main body portion 145 of the expandable member 127 move through the cylindrical portion 183 of the sleeve 131, the sleeve 131 constrains the width of the region of the main body moving through the sleeve 131 to be less than the width of the neck 301 of the product 22. Thereby, the main body 125 of the expandable member 127 may be inserted into the product 22 without contacting the neck 301 of the product 22. Once the main body 125 of the expandable member 127 moves out of the sleeve 131, the main body is no longer constrained by the sleeve 131 and the width of the main body 169 increases to 44mm. Figure 8c shows the expandable member 127 in the normal configuration immediately before being expanded to apply the forming operation to the product 22. The controller 133 then controls the pump 107 to introduce additional fluid into the expandable member 127 and increase the pressure applied to the inside of the expandable member 127 to 20bar. This causes the expandable member 127 to expand. The expansion of the expandable member 127 causes the plug 171 to exit the socket 173 and detach the main body portion 145 of the expandable member 127 from the lower end 181 of the mandrel 125. Additionally, the expansion of the expandable member 127 causes the expandable member 127 to urge the product 22 against inner surfaces of the parts 111,113 of the mould 103. The product 22 is thereby heated and compressed such that a thermoforming operation is applied to the product 22. The combination of transitioning the expandable member 127 from the inverted configuration to the normal configuration and detaching the expandable member 127 from the mandrel 125 may be referred to as a post-insertion operation. Prior to applying the thermoforming operation to the product 22, the product 22 had a water content of 70% of the mass of the product 22. The thermoforming operation causes the water content to decrease such that the product 22 has a water content of 2% immediately after the thermoforming operation. The product 22 having a water content of greater than 5% immediately after the thermoforming operation is also envisaged. The controller 133 then controls pump 107 to withdraw the fluid from the expandable member 127. This causes the expandable member 127 to contract back to the normal configuration. The contraction causes the plug 171 to re-enter the socket 173 and attach the lower end 181 of the mandrel 125 to the expandable member 127. The controller 133 then controls the actuator 142 to transition the expandable member 127 from the normal to the inverted configuration (shown in Figure 8d). This may be referred to as a pre-withdrawal operation. Then the controller 133 controls the robotic arm to withdraw the mandrel system 105 from the thermoformed product 22 with the expandable member 127 in the inverted configuration (as shown in Figure 8e). The parts 111,113 of the mould 103 are then separated, and the product 22 is removed from the mould 103. In the above example, the attachment mechanism 129 comprises a plug 171 and a socket 173. In other examples, the attachment mechanism 129 is removed, and the expandable member 127 is permanently attached to the mandrel 125. In some examples, the mandrel 125 comprises a first and second part. The main body portion 145 of the expandable member 127 is attached to the second part of the mandrel 125 during movement of the mandrel 125 to transition the expandable member 127 from the normal configuration to the inverted configuration and during expansion of the expandable member 127. The second part moves relative to the first part (for example, the mandrel 125 maybe telescopic) in response to the expansion of the expandable member 127. In the above example, when in the inverted configuration, the second region 217 of the main body portion 145 of the expandable member 127 is located within the sleeve 131 (and thereby located within the neck portion 141 of the expandable member 127). In other examples, when in the inverted configuration, the main body 125 of the expandable member 127 may be inside out compared with the normal configuration (as shown in Figure 9). When the main body 125 of the expandable member 127 is inside out, the whole of the main body 125 of the expandable member 127 is located on an opposite side (the second side 211) of the connector 123 to the side that the main body is on when in the normal configuration (the first side 203). In these examples the sleeve 131 may have a different geometry (for example, the sleeve 131 may be shorter) or may be omitted. In the above example, the expandable member 127 has a varying wall thickness. In other examples, the expandable member 127 has a constant wall thickness along the length of the expandable member 127. In the above example, the mandrel system 105 comprises a sleeve 131, and the width 218 of the second region 217 of the main body portion 145 of the expandable member 127 is constrained by the cylindrical portion 183 of the sleeve 131 when the main body 125 of the expandable member 127 passes through, oris located in, the sleeve 131. In other examples, the sleeve 131 is omitted, and the width 218 of the second region 217 of the main body portion 145 of the expandable member 127 is constrained by cylindrical region 149 of the neck portion 141 of the expandable member 127 when the main body 125 of the expandable member 127 passes through, or is located in, the cylindrical region 149 of the neck portion 141 of the expandable member 127. In the above example, the width 161 of the cylindrical region 149 of the neck portion 141 of the expandable member 127 is 85% of the width 305 of the neck 301 of the product 22 when the expandable member 127 is in the inverted configuration. It is also envisaged for the width 161 of the cylindrical region 149 of the neck portion 141 of the expandable member 127 to be no greater than 99% of the width 305 of the neck 301 of the product 22 when the expandable member 127 is in the inverted configuration. It will be appreciated that there is provided a mandrel system control system (such as the controller 133 described above) that is configured to cause a mandrel system to: move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member between a first position to a second position, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. Also provided is a mould system control system (such as the controller 133 described above) that is configured to cause a mould system to: move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member from a first position to a second position; and at least one of: insert the mandrel, with the mandrel in the second position relative to the connector, into a mould of the mould system; and withdraw the mandrel, with the mandrel in the second position relative to the connector, from the mould, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. Figure 10a shows a schematic diagram of a non-transitory computer-readable storage medium 1000 according to an example. The non-transitory computer-readable storage medium 1000 stores instructions 1030 that, if executed by a processor 1020 of a mandrel system control system 1010, cause the mandrel system to perform a method according to an example. In some examples, the mandrel system control system 1010 is or comprises the controller 133 as described above. The instructions 1030 cause a mandrel system to: move 1031 a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member between a first position to a second position, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value.. In other examples, the instructions 1030 comprise instructions to perform any other example methods described herein. Figure 10b shows a schematic diagram of a non-transitory computer-readable storage medium 1050 according to an example. The non-transitory computer-readable storage medium 1050 stores instructions 1053 that, if executed by a processor 1055 of a mould system control system 1057, cause a mould system to perform a method according to an example. In some examples, the mould system control system 1057 is or comprises the controller 133 as described above. The instructions 1053 cause a mould system to: move 1061 a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member from a first position to a second position; and at least one of: insert 1063 the mandrel, with the mandrel in the second position relative to the connector, into a mould of the mould system; and withdraw 1065 the mandrel, with the mandrel in the second position relative to the connector, from the mould, wherein: when in the first position, a distance between the connector and the end of the mandrel has a first value; and when in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value. In other examples, the instructions 1030 comprise instructions to perform any other example methods described herein. Figure 11 shows a method 1100 according to an example. The method comprises: providing a hollow moulded fibre product 1101; providing 1103 an expandable member comprising a first portion, and a second portion which defines an opening of the expandable member, wherein the expandable member comprises a normal configuration and an inverted configuration, wherein, in the inverted configuration, at least one of: the first portion is located in the second portion, and the expandable member is inside out compared to the normal configuration; moving 1105 the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration; and at least one of: inserting 1107 the expandable member, in the inverted configuration, into the hollow moulded fibre product; and withdrawing 1109 the expandable member, in the inverted configuration, from the hollow moulded fibre product. It will also be appreciated that there also is provided a receptacle manufacturing line (such as that shown in Figure 1) comprising a mould system (such as that shown in Figure 2) for processing a hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle. Similarly, also provided is a method of manufacturing a receptacle, the method 1111 comprising the method 1100 of Figure 11, and then performing at least one additional process 1113 on the hollow moulded fibre product to provide the receptacle. Examples of the “at least one additional process” are described above with reference to Figure 1. Also provided, as a result of the content of the present application, is use of a receptacle obtained by any of the methods described herein to contain contents. An example such receptacle 1200, in the form of a necked receptacle and specifically a bottle, containing contents 1210 is shown in Figure 12. The use could be, for example, by a person who puts the contents into the receptacle, by a person who transports the contents, or by a person who wishes to dispose of (for example, to a consumer or end user), offer to dispose of (for example, to a consumer or end user), import, or keep the contents whether for disposal or otherwise. The contents could, for example, be any one or more of the example contents described herein. Also provided is a method of providing a content-containing receptacle. An example such method 1300 is shown in Figure 13. The method 1300 comprises providing 1310 the receptacle, in the form of a necked receptacle and specifically a bottle, and then providing 1320 the contents in the receptacle. In this example, block 1320 follows block 1310, so that block 1320 comprises putting the contents into the receptacle that has been provided at block 1310. However, in some other examples, blocks 1310 and 1320 are performed concurrently, so that the providing 1310 the receptacle comprises providing the receptacle with the contents already present in the receptacle. The contents could, for example, be any one or more of the example contents described herein. The method 1300 also comprises closing 1330 an opening of the receptacle after block 1320, and applying 1340 a label or indicia to the receptacle after block 1330. In this example, block 1330 involves applying a heat seal to the opening and then screwing a cap or lid onto the receptacle, and block 1340 comprises adhering a label onto the receptacle. In respective other examples, the order of blocks 1330 and 1340 is reversed, blocks 1330 and 1340 are performed concurrently, block 1330 is omitted, and block 1340 is omitted. In some examples, block 1340 occurs before block 1320, orblock 1340 occurs during block 1320. For example, in some cases, the label or indicia is applied to the receptacle, then the contents are provided in the receptacle, and then the receptacle is closed. It will be appreciated that the method 1300 could be performed by the same party that manufactures the receptacle, for example so that block 1310 comprises the method discussed above with reference to the manufacturing line shown in Figure 1. Alternatively, the method 1300 could be performed by a different party to that which manufactures the receptacle. In such an alternative, the different party performs block 1310 by way of obtaining the receptacle from the party that manufactures the receptacle (such as by way of the method discussed above with reference to Figure 1) or from an intermediary. Example embodiments of the present invention have been discussed, with 5 reference to the examples illustrated. However, it will be appreciated that variations and modifications may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A method comprising:providing a hollow moulded fibre product;providing an expandable member comprising a first portion, and a second portion which defines an opening of the expandable member, wherein the expandable member comprises a normal configuration and an inverted configuration, wherein, in the inverted configuration, at least one of: the first portion is located in the second portion, and the expandable member is inside out compared with the normal configuration;moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration;and at least one of:inserting the expandable member, in the inverted configuration, into the hollow moulded fibre product; andwithdrawing the expandable member, in the inverted configuration, from the hollow moulded fibre product.

2. The method of claim 1, wherein:the hollow moulded fibre product is a necked hollow moulded fibre product, and comprises a main body and a neck;the neck has a width which is less than a width of the main body;the second portion has a width which is less than the width of the neck when the expandable member is in the normal configuration and the inverted configuration; andthe first portion has a width which is less than the width of the main body and greater than the width of the neck when the expandable member is in the normal configuration.

3. The method of claim 2, wherein:moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration comprises at leastone of: moving the first portion into the second portion, and moving the first portion through the second portion; andwhen the first portion is located in the second portion or the first portion is moving through the second portion, a width of the first portion is constrained to be less than the width of the neck as a result of the first portion being located in or moving through the second portion.

4. The method of claim 3, wherein, in the inverted configuration, no less than 10% of a length of the first portion is located in the second portion.

5. The method of claim 3 or claim 4, wherein the width of the second portion of the expandable member is no greater than 99% of the width of the neck when the expandable member is in the inverted configuration.

6. The method of any one of the preceding claims, wherein:the method comprises providing a sleeve in the second portion; andmoving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration comprises at least one of: moving the first portion into the sleeve, and moving the first portion through the sleeve.

7. The method of claim 6, wherein a Young’s modulus of the sleeve is greater than a Young’s modulus of the expandable member.

8. The method of claim 6 or claim 7, wherein a coefficient of friction between the sleeve and the first portion of the expandable member is less than a coefficient of friction between the first portion of the expandable member and the second portion of the expandable member.

9. The method of any one of the preceding claims, wherein the expandable member comprises a wall thickness which is constant along a length of the expandable member.

10. The method of any one of the preceding claims, wherein:the method comprises applying a pressure to an inside of the expandable member whilst moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration; andthe pressure is greater than an ambient pressure on an outside of the expandable member.

11. The method of claim 10, wherein the pressure is no less than Ibar.

12. The method of claim 10 or claim 11, wherein the pressure is no greaterthan 2b ar.

13. The method of any one of the preceding claims, wherein the method comprises:providing a mandrel in the expandable member and attached to the first portion of the expandable member; andmoving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration comprises moving a point of attachment of the mandrel to the expandable member towards the opening.

14. The method of claim 13, wherein:the mandrel comprises an attachment mechanism for detachably attaching the mandrel to the first portion of the expandable member; andthe method comprises performing at least one of a post-insertion operation and a pre-withdrawal operation,the post-insertion operation comprising, after the insertion of the expandable member, in the inverted configuration, into the hollow moulded fibre product, moving the point of attachment of the mandrel to the expandable member away from the opening to move the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration; anddetaching the mandrel from the first portion; andthe pre-withdrawal operation comprising, before the withdrawal of the expandable member, in the inverted configuration, from the hollow moulded fibre product:attaching the mandrel to the first portion; andmoving the point of attachment of the mandrel to the expandable member towards the opening to move the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration.

15. The method of claim 13, wherein:the mandrel comprises a first part and a second part;the method comprises expanding the expandable member;the second part of the mandrel is attached to the first portion of the expandable member during moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration, and during expanding the expandable member; andthe method comprises moving the second part in response to expanding the expandable member.

16. The method of any one of the preceding claims, wherein:the method comprises:providing a mould;locating the hollow moulded fibre product within the mould; and performing at least one of a first operation and a second operation;wherein the first operation comprises:moving the first portion away from the opening to transition the expandable member from the inverted configuration to the normal configuration after the inserting the expandable member, in the inverted configuration, into the hollow moulded fibre product; andintroducing fluid into the expandable member to expand the expandable member so as to urge the hollow moulded fibre product against an inner surface of the mould when the expandable member is in the normal configuration; andwherein the second operation comprises:introducing fluid into the expandable member to expand the expandable member so as to urge the hollow moulded fibre product against an inner surface of the mould;moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration after introducing fluid into the expandable member to expand the expandable member; andwithdrawing the expandable member, in the inverted configuration, from the hollow moulded fibre product after moving the first portion towards the opening to transition the expandable member from the normal configuration to the inverted configuration.

17. The method of claim 16, wherein after the introducing fluid into the expandable member to expand the expandable member and the applying heat to the hollow moulded fibre product, the product has a fluid content which is greater than 5% of the mass of the product.

18. A mandrel system for use in processing a hollow moulded fibre product, the mandrel system comprising:a mandrel comprising an end attachable to a first portion of an expandable member; anda connector attachable to a second portion of the expandable member, the second portion defining an opening of the expandable member, wherein:the mandrel is moveable relative to the connector between a first position to a second position;when in the first position, a distance between the connector and the end of the mandrel has a first value; andwhen in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value.

19. The mandrel system of claim 18, wherein:the mandrel is moveable relative to the connector between at least one of the first position and the second position to a third position; andthe third position is located on an opposite side of the connector to a side on which the first position and the second position are located.

20. A mould system for processing a hollow moulded fibre product, the mould system comprising:the mandrel system of claim 17 or claim 18, anda mould for receiving the hollow moulded fibre product,wherein the mandrel system is insertable into and withdrawable from the mould, and usable with the mould to process the hollow moulded fibre product.

21. A mandrel system control system configured to cause a mandrel system to:move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member between a first position to a second position, wherein:when in the first position, a distance between the connector and the end of the mandrel has a first value; andwhen in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value.

22. A non-transitory storage medium storing machine-readable instructions that, when executed by a processor of a mandrel system control system, cause a mandrel system to:move a mandrel comprising an end attachable to a first portion of an expandable member relative to a connector attachable to a second portion of the expandable member between a first position to a second position, wherein:when in the first position, a distance between the connector and the end of the mandrel has a first value; andwhen in the second position, the distance between the connector and the end of the mandrel has a second value which is no greater than 25% of the first value.

23. A receptacle manufacturing line comprising the mould system of claim 19 for processing the hollow moulded fibre product and apparatus for performing at least one additional process on the hollow moulded fibre product to provide the receptacle.

524. A method of manufacturing a receptacle, the method comprising performing the method of any one of claims 1 to 16, and then performing at least one additional process on the hollow moulded fibre product to provide the receptacle.10 25. A method of providing a content-containing receptacle, the methodcomprising providing a receptacle obtained by the method of claim 23 and providing the contents in the receptacle to provide the content-containing receptacle.15

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