Expandable member for container forming

Abstract

An inflatable member used when molding a container within a cavity of a mold, the inflatable member including a neck portion, a body portion, and a bottom portion. The neck portion defines an opening of the inflatable member, and the neck portion has a first width. The body portion is proximal to the neck portion and has a second width different from the first width. The bottom portion is located at an end of the body portion opposite the neck portion and has a third width greater than the second width.

Description

Technical Field

[0001] The present invention relates to a method and system for forming a shaped container from a fiber suspension such as a fiber suspension containing paper pulp, and an inflatable member used in such a method and system. The container can form consumer packaging useful for holding liquids, powders, other flowable materials, or solids, such as bottles.

Background Art

[0002] It is desirable to reduce the use of plastics, especially those used in packaging. Trays and other simple shapes are generally made from paper pulp, but more complex objects such as bottles are more difficult to fabricate.

[0003] For example, it can be difficult to compress paper pulp in a mold to reliably form a bottle with sufficient wall thickness and strength.

Summary of the Invention

[0004] According to a first aspect of the present invention, there is provided an inflatable member for use in forming a container within a cavity of a mold, the inflatable member comprising a neck portion defining an opening of the inflatable member, the neck portion having a first width, a body portion proximal to the neck portion, the body portion having a second width different from the first width, and a bottom portion located at an end of the body portion opposite the neck portion, the bottom portion having a third width greater than the second width.

[0005] For example, by providing an inflatable member in which the bottom portion is wider than the body portion as compared to an inflatable member in which the body portion and the bottom portion have the same width, when the inflatable member expands, the bottom portion is more likely to be urged to move towards the periphery of the bottom of the container. Thereby, it is ensured that the inflatable member can contact the peripheral region of the bottom of the container with sufficient pressure, and it can be ensured that the manufacturing material of the container is sufficiently compressed.

[0006] In the case of an inflatable member where the body portion and the bottom portion have the same width, during use, the inflatable member first contacts the bottom of the container, causing friction, which prevents the inflatable member from subsequently expanding towards the periphery of the bottom of the container. As a result, the periphery of the container may not be sufficiently compressed, and thus, vulnerable points may occur in the completed container. The finish of the inner and outer surfaces of the container can also become unacceptably rough. By providing an inflatable member with a bottom portion that is wider than the body portion, these factors can be mitigated.

[0007] As used herein, the width may include the maximum width between two opposing points on the outer surface of the relevant portion of the inflatable member. The width discussed herein may include the width measured when the opening is exposed to the surrounding external air, for example, when the inflatable member is supported with substantially no radial inward or outward pressure applied to the inflatable member.

[0008] Optionally, the second width is greater than the first width. This can facilitate the formation of a container, such as a bottle, with a relatively narrow neck and a relatively wide body.

[0009] Optionally, the third width is no more than 1.2 times the second width. This can facilitate the bottom portion moving towards the periphery of the bottom of the container while avoiding the formation of a friction lock between the bottom portion and the bottom of the container when the inflatable member expands.

[0010] Optionally, the bottom portion is rounded. Optionally, the bottom portion has the shape of a spherical dome. Such a shape can facilitate the bottom portion moving towards the periphery of the bottom of the container, for example, as compared to a bottom portion with a flat lower surface.

[0011] Optionally, the wall of the main body portion varies in wall thickness along the length of the wall. Since the wall of the main body portion varies in wall thickness along the length of the wall, the expansion of the main body portion of the expandable member can be controlled. For example, a thinner region of the wall can expand more than a thicker region of the wall. Thus, by changing the wall thickness of the main body portion, the contact between the main body portion and the container when the expandable member expands can be controlled. By controlling such contact, the forming of the container can be promoted.

[0012] Specifically, the contact points between the expandable member and the container can affect the subsequent expansion of the expandable member within the container as a result of friction. Thus, by controlling which region of the main body portion of the expandable member first contacts the container, the subsequent expansion and contact points of the expandable member can be controlled. Thereby, it is ensured that the expandable member can contact a specific region of the container with sufficient pressure, and it can be ensured that the manufacturing material of the container is sufficiently compressed. Thus, with such an expandable member, the strength of the container can be made more uniform, for example, compared to a container formed using an expandable member with a constant thickness of the main body portion.

[0013] Optionally, the wall thickness gradually changes along the length of the wall. This can result in desirable expansion characteristics, for example, compared to a wall having one or more discrete or stepwise changes in thickness along the length of the wall.

[0014] Optionally, the wall thickness changes uniformly along the length of the wall, for example, the thickness does not change stepwise. Optionally, the wall thickness tapers along the length of the wall, for example, along substantially the entire length of the wall.

[0015] Optionally, the body portion has a shoulder portion proximal to the neck portion and a lower portion distal to the neck portion. The shoulder portion has a first wall thickness, and the lower portion has a second wall thickness that is thicker than the first wall thickness. By having a relatively thin shoulder portion and a relatively thick lower portion, upon inflation of the inflatable member, the contact between the body of the inflatable member and the container can be controlled such that the shoulder portion contacts the container before the lower portion. Next, the shoulder portion can be locked in place relative to the container by friction, and then the remainder of the body portion of the inflatable member expands and contacts the container while filling the container.

[0016] Optionally, the second wall thickness is 1.2 to 2.0 times the first wall thickness. Such a ratio can provide desirable inflation characteristics of the inflatable member while ensuring that the wall thickness of the body portion does not change too much. Thereby, for example, the manufacture of the inflatable member can be facilitated.

[0017] Optionally, the second wall thickness is 1.4 to 1.8 times the first wall thickness. Optionally, the second wall thickness is about 1.6 times the first wall thickness.

[0018] Optionally, the first wall thickness is about 1.2 mm to 4.0 mm. Optionally, the first wall thickness is about 1.5 mm to 3.0 mm. Optionally, the first wall thickness is about 2.7 mm.

[0019] Optionally, the second wall thickness is about 1.7 mm to 7.2 mm. Optionally, the second wall thickness is about 2.1 mm to 5.4 mm. Optionally, the second wall thickness is about 4.4 mm.

[0020] Optionally, the neck portion has an additional wall with an additional wall thickness that is thicker than the maximum wall thickness of the wall of the body portion. By having an additional wall that is relatively thick compared to the wall of the body portion in the region of the opening of the inflatable member, for example, in the region where the inflatable member can be connected to the inflation fluid source used, an increase in strength can be achieved. Also, by having the additional wall of the neck portion be relatively thick compared to the wall of the body portion, inflation of the body portion can be promoted more than that of the neck portion. This can be beneficial, for example, when the body portion is wider than the neck portion.

[0021] Optionally, the second width is the maximum width of the body portion. Optionally, the width of the body portion varies along its length. Optionally, the minimum width of the body portion corresponds to the portion adjacent to the neck portion. Optionally, the second width is away from the bottom portion, for example, closer to the neck portion than the bottom portion. Optionally, if there is an interface between the shoulder portion and the lower portion, the second width occurs at the interface between the shoulder portion and the lower portion. Optionally, the shoulder portion has an increasing width between the neck portion and the lower portion.

[0022] Optionally, the third width is about 25 mm to 70 mm, for example, about 40 mm to 55 mm.

[0023] Optionally, the third width is greater than the second width and is 1.1 times or less, 1.05 times or less, or 1.01 times or less of the second width.

[0024] Optionally, the second width is about 24 mm to 69 mm, for example, about 39 mm to 54 mm.

[0025] Optionally, the second width is greater than the first width and is 1.8 times or less, 1.7 times or less, 1.6 times or less, or 1.5 times or less of the first width.

[0026] Optionally, the first width is about 23 mm to 68 mm, for example, about 38 mm to 53 mm.

[0027] Optionally, the second wall thickness is the maximum wall thickness of the body portion.

[0028] Optionally, the further wall thickness is 1.1 to 1.5 times the second wall thickness. Optionally, the second wall thickness is about 1.2 times the first wall thickness.

[0029] Optionally, the further wall thickness is about 3.1 mm to 10.8 mm. Optionally, the second wall thickness is about 3.9 mm to 8.1 mm. Optionally, the first wall thickness is about 5.2 mm.

[0030] Optionally, the transition region between the body portion and the bottom portion includes a region where the thickness is reduced as compared to the adjacent region of the body portion. Thereby, the bottom portion can be promoted to advance toward the peripheral edge of the bottom of the container. Thereby, before the adjacent region of the body portion comes into contact with the container and potentially engages in frictional engagement with the container, the bottom portion can be made to advance toward the peripheral edge of the bottom of the container.

[0031] Optionally, the adjacent region of the body portion includes the maximum wall thickness region of the body portion. Optionally, the adjacent region of the body portion refers to a region of the body portion that extends in a direction away from the transition region and is within 5% of the total length of the body portion.

[0032] Optionally, the bottom portion includes a wall having a wall thickness that substantially corresponds to the maximum wall thickness of the body portion. Optionally, the bottom portion includes a wall having a wall thickness that is thinner than the maximum wall thickness of the body portion.

[0033] Optionally, the wall thickness of the bottom portion varies, and the minimum wall thickness of the bottom portion is located between the farthest portion of the bottom portion from the opening and the transition region between the body portion and the bottom portion. Such a minimum wall thickness position can promote the bottom portion to expand toward the peripheral edge of the container when the expandable member used expands.

[0034] Optionally, the difference between the third width and the first width is greater than the maximum wall thickness of the body portion.

[0035] Optionally, the expandable member has a monolithic component, for example, such that the body portion and the neck portion are integrally formed. For example, the expandable member can have a single-wall structure shaped to define various portions of the expandable member described herein.

[0036] Optionally, the expandable member includes, or is made of, an elastically deformable material. Optionally, the expandable member includes, or is made of, a rubber material. Optionally, the expandable member includes, or is made of, a silicon material.

[0037] Optionally, the inflatable member is formed from a material having a Shore A hardness of 20 to 50, for example, a Shore A hardness of about 40.

[0038] Optionally, the shape and dimensions of the aforementioned inflatable member include the shape and dimensions of the inflatable member in a partially inflated configuration. For example, without deforming the wall of the inflatable member, sufficient fluid is contained within the hollow interior of the inflatable member such that the inflatable member has a defined shape.

[0039] According to a second aspect of the present invention, a container molding system is provided. The container molding system includes a container mold having a mold cavity for receiving a constituent component, where the constituent component is a fiber suspension or a partially formed container, and an inflatable member according to the first aspect of the present invention that is inflatable within the mold cavity so as to press the constituent component against the inner surface of the mold cavity during the process of forming a container from the constituent component.

[0040] Optionally, the container molding system includes an inflation fluid source that can be fluidly connected to the inflatable member, thereby enabling selective supply of inflation fluid into the interior of the inflatable member when the inflatable member is inserted into the mold cavity. Thus, the inflatable member can expand when it is within the mold cavity being used and contact the fiber suspension or the partially formed container held within the mold cavity to apply pressure.

[0041] Optionally, the container molding system includes a heat source for supplying heat to the constituent component when the constituent component is held within the mold cavity. Thus, using such a system, a thermoforming process can be performed on the constituent component when the constituent component is held within the mold cavity.

[0042] Optionally, the container molding system includes, for example, a bottle molding system for molding a bottle from a fiber suspension.

[0043] Optionally, the container forming system is at least one of a fiber container forming system and a paper pulp container forming system.

[0044] According to a third aspect of the present invention, a method of forming a container is provided, the method comprising supplying a component into a mold cavity of a mold, the component being a fiber suspension or a partially formed container, the supplying, providing an expandable member of the first aspect of the present invention into the mold cavity, and expanding the expandable member to press the component against an inner surface of the mold cavity during the process of forming the container from the component.

[0045] Optionally, the method includes applying heat to the component within the mold cavity. Thus, using such a method, a thermoforming process can be performed on the component while the component is held within the mold cavity.

[0046] Optionally, the method is a method of forming at least one of a fiber container and a paper pulp container.

[0047] According to a fourth aspect of the present invention, there is provided a container obtainable from a manufacturing method including the method of the third aspect of the present invention, or a container to be obtained.

[0048] For example, the container may be obtainable from, or obtained by, the method of the third aspect of the present invention.

[0049] Optionally, the container is at least one of a fiber container and a paper pulp container.

[0050] The manufacturing method may include at least one additional process. The at least one additional process may include coating and drying the container to produce a coated container. The at least one additional process may include attaching a closure to the container or the coated container.

[0051] In some embodiments, the container is a bottle.

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

Brief Description of the Drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

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

[0055] Figure 1 shows a process for making a bottle from paper pulp (i.e., paper pulp that can form the basis of an exemplary fiber suspension). This process is merely exemplary and is provided to give context to embodiments of the present invention. Broadly speaking, the exemplary process involves supplying a fiber suspension, introducing the fiber suspension into the mold cavity of a porous first mold, using the porous first mold to drain liquid (such as water) from the fiber suspension to create a wet precursor or embryo (which can itself be regarded as a formed container), further shaping the wet precursor in the mold to create a further formed container, further coating the further formed container to create a coated formed container, drying the coated formed container to create a dried container, and attaching a closure to the dried container. As will be apparent at least from the following description, by modifying the exemplary process, variant forms of the process can be provided in which other embodiments of the present invention can be realized.

[0056] In this example, supplying the fiber suspension includes preparing the fiber suspension from its raw materials. More specifically, preparing includes supplying pulp fibers such as paper pulp fibers and mixing the pulp fibers with a liquid to supply hydrated pulp fibers. In this example, the pulp fibers are supplied in the form of sheets from a supplier, and the liquid includes water and one or more additives. In this example, the liquid is mixed with the pulp fibers to supply hydrated pulp fibers having a solid fiber content of 1 wt% to 5 wt% (based on the dry mass of the fibers). In the example, one or more additives include sizing agents such as alkyl ketene dimer (AKD). The hydrated pulp fibers typically contain AKD in an amount of 0.4 wt% based on the total dry mass of the solid fibers in the hydrated pulp fibers. In some examples, one or more additives are present in the liquid at the time of mixing the pulp fibers with the liquid. In some examples, after mixing the pulp fibers with the liquid, one or more additives are added to the hydrated pulp fibers (for example, the pulp fibers are hydrated for a period of time, for example 2 to 16 hours, and then one or more additives are supplied to the hydrated pulp fibers). The hydrated pulp fibers pass between the plates of a valley beater 11 or a refiner that are moving relative to each other. Thereby, some or all of the fibers are fibrillated, that is, the cell walls of these fibers are partially delaminated, and the wet surfaces of these fibers have protruding hairs or fibrillations. These fibrillations help to increase the bond strength between the fibers in the dried final product. In other examples, the valley beater 11 or the refiner may be omitted.

[0057] The resulting processed pulp is stored in tank 12 in a relatively concentrated form (e.g., 1 wt% - 5 wt% solid fiber content) to reduce the required storage space. At an appropriate time, the processed pulp is transferred to mixing station 13, where the processed pulp is diluted with additional water and optionally mixed with one or more additives (in addition to, or instead of, one or more additives supplied with the aqueous pulp fibers), and a fiber suspension in a state ready for forming is supplied. In this example, the solid fibers account for 0.7 wt% (by dry weight of the fibers) of the resulting fiber suspension, but in other examples, the proportion of solid fibers in the fiber suspension may vary, such as another value within the range of 0.5 wt% - 5 wt% or 0.1 wt% - 1 wt% (by dry weight of the fibers) of the fiber suspension. In some examples, the one or more additives mixed with the processed pulp and water include dehydrating agents such as modified and / or unmodified polyethyleneimine (PEI), such as the modified PEI sold under the trademark Polymin® SK. In some examples, one or more additives are mixed with water, and then the water and one or more additives are mixed with the processed pulp, and in other examples, the processed pulp is mixed with water, and then one or more additives are mixed with the processed pulp and water. The fiber suspension typically contains Polymin® SK in an amount of 0.3 wt% based on the total dry mass of the solid fibers. Mixing of the fiber suspension at mixing station 13 helps to homogenize the fiber suspension. In other examples, the processed pulp or fiber suspension may be supplied in other ways, such as being supplied ready-made.

[0058] In this example, the porous first mold 15 has two half-molds, and these two half-molds are movable closer to or away from each other using a hydraulic ram in this case. In this example, each of the half-molds is a monolithic or integral tool formed by additive manufacturing (e.g., 3D printing) that defines a mold contour. When the half-molds are in contact with each other, their respective mold contours cooperate to define a mold cavity for forming a wet precursor or a forming container. Each half-mold may itself define a smaller mold cavity, and when in cooperation with the second half-mold, the smaller mold cavities can be combined to provide the entire mold cavity. The two half-molds can themselves be regarded as "split parts" or "molds", and the entire porous first mold 15 can be regarded as a "split mold" or similarly a "mold". In other examples, the porous first mold 15 can have more than two split parts, such as three, four, or six split parts that cooperate to define a mold cavity.

[0059] In FIG. 1, the fiber suspension (also known as a slurry) is filled into the porous mold 15 from above, which is different from a molding process of immersing the mold in the slurry. The fiber suspension is drawn into the porous mold 15 via line 16 under vacuum, and the excess suspension is drawn into the tank 17 via line 18 under vacuum through the porous mold 15. The injection mass can be controlled by measuring (e.g., metering) the amount of liquid drawn into the tank 17. A weighing platform supporting the tank 17 is shown in FIG. 1. When the required amount (e.g., a predetermined volume such as 10 liters, or a predetermined mass such as 10 kilograms) of liquid is collected in the tank 17, the suction of the suspension through the porous mold 15 is stopped, and the porous mold 15 is opened and exposed to the ambient air. In this example, the suspension drawn in with the fiber suspension at line 16 is water or mainly water (additives may also be present). Since the fibers remain on the walls of the porous mold 15 to form an embryo of the forming container, the liquid drawn into the tank 17 via line 18 under vacuum is substantially fiber-free.

[0060] In one embodiment, to further remove the suspension (e.g., water) from the embryo and to form or strengthen the three-dimensional shape of the container, an impermeable expansion element 19, such as a foldable bladder, is inserted into the porous mold 15 and inflated to function as the internal high-pressure core structure of the porous mold 15. This process strengthens the wet embryo into a handleable state and discharges the water between the fibers, thereby improving the efficiency of the subsequent drying process. The expansion element 19 is actuated and adjusted using a fluid pump 20. The pump 20 has a cylinder that moves the fluid in line 21 into the expansion element 19 to expand the expansion element 19 radially to fit the mold cavity. The fluid in line 21 is preferably incompressible, such as water. Also, water has the advantage that no new substances are introduced into the system due to any leakage or rupture of the bladder 19 (since the suspension is already water or mainly water).

[0061] Demolding is performed when the porous mold 15 is open, and the self-standing formed container 22 is removed. Subsequently, it is preferable to perform mold cleaning 23 to remove small fibers and maintain the porosity of the porous mold 15. In this embodiment, while the mold 15 is open, a high-pressure jet emitted radially is inserted into the mold cavity. Thereby, the fibers are removed from the wall of the mold cavity. Alternatively or additionally, water from the tank 17 is pressurized through the back of the porous mold 15 to remove the trapped fibers. The water is discharged and returned to the upstream part of the system for reuse. It should be noted that cleaning is important to adjust and reuse the porous mold 15. After the container is removed, the porous mold 15 may appear clean, but its performance can be impaired if not cleaned.

[0062] According to FIG. 1, the formed but unfinished container 22 is then transferred to a second forming station where, for example, in an aluminum mold 25, pressure and heat are applied to perform thermoforming of a desired neck and surface finish, optionally including embossed and / or debossed surface features. After the two halves of the mold 25 are closed around the container 22, a pressurizer comes into play. For example, a bladder 26 (e.g., a thermoforming bladder 26) is inserted into the container 22. The bladder 26 is expanded via line 27 by a pump 28 and a pressurized fluid, such as air, water, or oil, is supplied. Optionally, during supply, the pressurized fluid is heated, for example, by a heater, or alternatively, cooled, for example, by a heat exchanger. The outer mold block 24 of the mold 25 and / or the mold 25 itself may be heated additionally or alternatively. Compared to the state at demolding from the porous mold 15, the state of the formed container 22 after thermoforming is considerably more rigid and the side walls are more compressed.

[0063] The drying stage 29 (e.g., a microwave drying process or other drying process) is performed downstream of the thermoforming as shown. In one embodiment, the drying stage 29 is performed before the thermoforming. However, the forming in the mold 25 requires some water content to assist in bonding during the compression process. FIG. 1 shows a further drying stage 30 after the drying stage 29, where, for example, hot air circulated within a “hot box” can be utilized against the formed container 22. In some embodiments, the microwave drying process or other drying process can be performed at multiple stages of the overall manufacturing process.

[0064] The formed container 22 is then subjected to a coating step, during which, in this example, the spraying rod 31 is inserted into the formed container 22 to apply one or more surface coatings to the inner wall of the formed container 22. In another example, the formed container 22 is instead filled with a liquid that coats the inner wall of the formed container 22. In practice, such a coating provides a protective layer to prevent the release of contents that can penetrate the bottle wall and / or weaken the bottle wall onto the bottle wall. The coating is selected according to the targeted contents of the container 22, such as beverages, detergents, pharmaceuticals, etc. In some examples, a further drying step 30 is performed after (or both before and after) the coating step. In this example, the formed container 22 is then subjected to a curing process 34, which can be configured or optimized according to the coating, for example, by drying for 24 hours under ambient conditions or by flash drying. For example, in some examples where a further drying step 30 is performed after the coating step, the curing process 34 can be omitted.

[0065] During a suitable stage of manufacture (e.g., during thermoforming or before or after coating), a process for forming a closure or mouth can be performed on the formed container 22. For example, as shown in FIG. 1, a neck fitting 35 can be attached. In some examples, an external coating is applied to the formed container 22 as shown in a further coating step 32. As shown in FIG. 1, in one example, the formed container 22 is immersed in a liquid that coats its outer surface. Thereafter, one or more further drying or curing processes can be performed. For example, the formed container 22 may be dried with warm air. Thus, the formed container 22 can be in a state where it is fully formed and ready to receive contents therein.

[0066] In the exemplary process of FIG. 1, using bladder 19, a fiber suspension in the form of a wet embryo is brought into contact with porous mold 15, and using thermoforming bladder 26, an unfinished container 22, which can be regarded as a partially formed container, is brought into contact with aluminum mold 25. In this way, a pressing force can be applied to the fiber suspension or the partially formed container to further form the desired shape of the final container.

[0067] An exemplary bladder 100, which may be useful in any of these steps of the exemplary process of FIG. 1, is shown in cross - section in FIG. 2. Here, bladder 100 is shown in a supported state, exposed to the surrounding external air, for example, a state in which substantially no radial inward or outward pressure is applied to bladder 100.

[0068] Bladder 100 is a one - piece structure formed of silicon with a Shore A hardness of about 40 and is substantially hollow. Bladder 100 has a neck portion 102, a body portion 104, and a bottom portion 106. Neck portion 102 is generally cylindrical and defines an opening 107 into the interior of the bladder. Neck portion 102 has a maximum width A of about 30 mm, measured between two diametrically opposed points on the outer surface of neck portion 102, and has a substantially constant wall thickness B of about 5.2 mm.

[0069] Body portion 104 begins at the end of neck portion 102 opposite opening 107 and includes a shoulder portion 108 proximal to neck portion 102 and a lower portion 110 distal to neck portion 102. Shoulder portion 108 has a shape that flares outward from neck portion 102 and has a substantially constant wall thickness C of about 2.7 mm. The interface between shoulder portion 108 and lower portion 110 occurs at the point of the maximum width D of body portion 104. The maximum width D of body portion 104, measured between two diametrically opposed points on the outer surface of body portion 104, is about 43 mm.

[0070] The lower portion 110 has a shape that tapers inwards from the maximum width D of the body portion 104 towards the bottom portion 106. The minimum width E of the lower portion 110, measured between two diametrically opposed points on the outer surface of the lower portion 110, is approximately 40 mm. From the wall thickness C of 2.7 mm of the shoulder portion 108 to the maximum wall thickness F of approximately 4.4 mm of the body portion 104, the wall thickness of the lower portion 110 gradually increases along the length of the lower portion 110 without a stepwise change in thickness. The maximum wall thickness F of the body portion 104 occurs at the distal end of the body portion 104 from the neck portion 102. Thus, the wall thickness of the body portion 104 increases along the length of the body portion 104 from a minimum wall thickness C of approximately 2.7 mm of the shoulder portion 108 to a maximum wall thickness F of approximately 4.4 mm of the lower portion 110.

[0071] The transition region 112 between the lower portion 110 and the bottom portion 106 has a wall thickness G that is approximately 3 mm less than the maximum wall thickness F of the lower portion 110.

[0072] The bottom portion 106 has the shape of a spherical dome and is located at the end of the body portion 104 opposite the neck portion 102. Thus, the body portion 104 is present between the neck portion 102 and the bottom portion 106. The bottom portion 106 has a maximum width H of approximately 44 mm, measured between two diametrically opposed points on the outer surface of the bottom portion 106. At this particular stage of expansion, this can be considered the maximum width of the entire bladder 100. The bottom portion 106 has a substantially constant wall thickness I of approximately 4 mm.

[0073] In use, the bladder 100 is utilized, for example, as a thermoformed bladder 26 and inserted into an unfinished container 22, i.e., a partially formed container, held within an aluminum mold 25.

[0074] The bladder 26 is expanded via a line 27 by a pump 28 that supplies a pressurized fluid, such as air, water, or oil, inside the bladder 26. Thereby, the bladder 26 expands and a pressing force is applied to the unfinished container 22 as part of the thermoforming process.

[0075] Since the wall thickness of the body portion 104 varies along the length of the wall, the expansion of the body portion 104 of the bladder 100 is controlled such that the thinner regions of the wall expand more than the thicker regions of the wall during expansion. Thus, by varying the wall thickness of the body portion 104, the contact between the body portion 104 and the unfinished container during the expansion of the bladder 100 is controlled. In the embodiment of FIG. 2, the relatively thin shoulder portion 108 of the wall expands before the relatively thick lower portion 110 of the wall, so that the shoulder portion 108 of the wall contacts the unfinished container 22 before the lower portion 110 of the wall contacts the unfinished container 22. Such expansion is schematically shown by the arrows in FIG. 3, and the relative sizes of the arrows are used to indicate the likelihood of expansion, with larger arrows indicating regions more likely to expand first.

[0076] By controlling such an initial contact point between the body portion 104 and the unfinished container 22, the subsequent expansion of the bladder 100 within the unfinished container 22 can be controlled. Specifically, in the bladder 100 of the embodiment of FIG. 2, during expansion, the shoulder portion 108 can expand first and contact the corresponding shoulder portion of the unfinished container 22, and then the remaining portion of the body portion 104 and further the bottom portion 106 can subsequently expand to fill the unfinished container 22. This ensures that the bladder can contact the unfinished container 22 with sufficient pressure and can ensure that the material of the unfinished container 22 is sufficiently compressed.

[0077] Thus, with the bladder 100, the strength of the container can be further increased and may be more uniform compared to, for example, a container formed using an expandable member with a constant thickness of the body portion.

[0078] By having a further wall portion that is relatively thick in the neck portion 102 compared to the wall of the body portion 104, an increase in strength can be provided in the region of the opening 107 of the bladder 100 where the bladder can be connected to the line 27 used. Also, by the further wall portion of the neck portion 102 being relatively thick compared to the wall of the body portion 104, the expansion of the body portion 104 can be promoted more than that of the neck portion 102. This can be beneficial because when the body portion 104 has a wider width than the neck portion 102, as is the case with most containers in bottle form, less expansion of the neck portion 102 is needed to achieve the desired compression.

[0079] Furthermore, the maximum width H of the bottom portion 106 is greater than the maximum width D of the body portion 104 and is further greater than the maximum width A of the neck portion 102. That is, for example, compared to a bladder where the body portion and the bottom portion have the same width, when the bladder 100 expands, the bottom portion 106 is more likely to be urged to move towards the peripheral edge of the bottom of the unfinished container 22. Thereby, it is ensured that the bladder 100 can contact the peripheral edge region of the bottom of the unfinished container 22 with sufficient pressure, and it can be ensured that the unfinished container is sufficiently compressed.

[0080] An exemplary method 300 by using the exemplary bladder 100 of FIG. 2 in the exemplary process of FIG. 1 is shown in the flowchart of FIG. 4. The method 300 includes supplying a component 302 into the mold cavity of the mold, where the component is a fiber suspension or a partially formed container. The method 300 includes providing the bladder 100 into the mold cavity 304. The method 300 includes expanding the bladder 100 such that a relatively thin region of the wall of the body portion 104 expands before a relatively thick region of the wall of the body portion 104 in order to press the component against the inner surface of the mold cavity during the process of forming the container from the component 306.

[0081] Although described above in relation to the unfinished container 22, it will be understood that the bladder 100 of the embodiment of FIG. 2 may be utilized to apply pressure to the wet embryo by the aforementioned method.

[0082] Also, it will be understood that the bladder in which the wall thickness of the main body portion 104 changes along the length of the main body portion 104 is not assumed to have the characteristic that the maximum width H of the bottom portion is greater than the maximum width D of the main body portion 104, and vice versa.

[0083] Furthermore, in the embodiment of FIG. 2, although the bladder 100 was described as having specific dimensions, it will be understood that the teachings of this specification may be equally applicable to bladders having other dimensions.

[0084] For example, bladders are assumed in which the wall thickness F of the lower portion 110 is about 1.2 to 2.0 times, 1.4 to 1.8 times, and about 1.6 times the wall thickness C of the shoulder portion 108. Bladders are assumed in which the wall thickness C of the shoulder portion 108 is about 1.2 mm to 4.0 mm, about 1.5 mm to 3.0 mm, and about 2.7 mm. Bladders are assumed in which the wall thickness F of the lower portion 110 is about 1.7 mm to 7.2 mm, about 2.1 mm to 5.4 mm, and about 4.4 mm.

[0085] Bladders are assumed in which the wall thickness B of the neck portion 102 is about 1.1 to 1.5 times, and about 1.2 times the wall thickness F of the lower portion 110. Bladders are assumed in which the wall thickness B of the neck portion 102 is about 3.1 mm to 10.8 mm, about 3.9 mm to 8.1 mm, and about 5.2 mm.

[0086] Bladders are assumed in which the maximum width H of the bottom portion is greater than the maximum width D of the main body portion 104 and is 1.1 times or less, 1.05 times or less, or 1.01 times or less the maximum width D of the main body portion 104. Bladders are assumed in which the maximum width H of the bottom portion is about 25 mm to 70 mm, for example about 40 mm to 55 mm. Bladders are assumed in which the maximum width D of the main body portion 104 is about 24 mm to 69 mm, for example about 39 mm to 54 mm.

[0087] A bladder is envisioned in which the maximum width D of the body portion 104 is greater than the maximum width A of the neck portion 102 and is 1.8 times or less, 1.7 times or less, 1.6 times or less, or 1.5 times or less the maximum width A of the neck portion 102. A bladder is envisioned in which the maximum width A of the neck portion 102 is about 23 mm to 68 mm, for example about 38 mm to 53 mm.

[0088] Other deformed configurations in which the wall thickness of portions of the bladder 100 changes are also envisioned. One such example is shown in FIG. 5, where the bottom portion has a maximum wall thickness J in the region corresponding to the bottom of the unfinished container 22, for example the region furthest from the opening 107, and a minimum wall thickness K in the region of the bottom portion 106 corresponding to the periphery of the bottom of the unfinished container 22. By providing an effective amount of the region of the minimum wall thickness of the bottom portion 106 at the corners of the bottom portion 106, the bladder 100 is promoted to expand and fill the region corresponding to the corners of the unfinished container 22, i.e., the junction of the side wall and the bottom, and it may be possible to apply sufficient compressive force to such regions of the unfinished container 22.

[0089] Exemplary embodiments of the invention have been described with reference to the illustrated embodiments. However, it will be understood that modifications and changes may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. An inflatable member used when forming a container in the cavity of a mold, A neck portion defining the opening of the inflatable member, the neck portion having a first width, The main body portion located proximal to the neck portion, having a second width different from the first width, The bottom portion is located at the end of the main body portion opposite to the neck portion, and has a third width that is greater than the second width, An expandable member comprising:

2. The expandable member according to claim 1, wherein the second width is greater than the first width.

3. The expandable member according to claim 1 or 2, wherein the third width is 1.2 times or less the second width.

4. The inflatable member according to claim 1 or 2, wherein the bottom portion is rounded.

5. The expandable member according to claim 1 or 2, wherein the wall of the main body portion has a wall thickness that changes along the length of the wall.

6. The expandable member according to claim 5, wherein the thickness of the wall gradually changes along the length of the wall.

7. The expandable member according to claim 5, wherein the main body portion has a shoulder portion located proximal to the neck portion and a lower portion located distal to the neck portion, the shoulder portion has a first wall thickness, and the lower portion has a second wall thickness that is greater than the first wall thickness.

8. The expandable member according to claim 7, wherein the second wall thickness is 1.2 to 2.0 times the first wall thickness.

9. The expandable member according to claim 5, wherein the neck portion has a further wall portion with a further wall thickness that is thicker than the maximum wall thickness of the wall of the main body portion.

10. The expandable member according to claim 5, wherein the transition region between the main body portion and the bottom portion includes a region in which the thickness is reduced compared to the adjacent region of the main body portion.

11. The expandable member according to claim 1 or 2, wherein the wall thickness of the bottom portion changes, and the minimum wall thickness of the bottom portion is located between the opening, the most distal portion of the bottom portion, and the transition region between the main body portion and the bottom portion.

12. A container molding system, A container mold having a mold cavity for receiving components, wherein the components are a fiber suspension or a partially formed container, and the container mold, An expandable member according to claim 1 or 2, wherein the expandable member is expandable within the mold cavity during the process of forming the container from the components such that the components are pressed against the inner surface of the mold cavity, A container molding system equipped with the following features.

13. The container molding system according to claim 12, further comprising an expansion fluid source fluid-connectable to the expandable member, thereby enabling selective supply of expansion fluid to the interior of the expandable member when the expandable member is inserted into the mold cavity.

14. The container molding system according to claim 12, further comprising a heat source for supplying heat to the components when the components are held in the mold cavity.

15. The container molding system according to claim 12, wherein the container molding system is at least one of a fiber container molding system and a paper pulp container molding system.

16. A method for forming a container, The process involves supplying components into the mold cavity of a mold, wherein the components are a fiber suspension or a partially formed container, and the process of supplying these components. To provide an expandable member according to claim 1 or 2 within the mold cavity, and to inflate the expandable member so as to press the components against the inner surface of the mold cavity during the process of forming the container from the components. Methods that include...

17. The method according to claim 16, comprising applying heat to the constituent components within the mold cavity.

18. The method according to claim 16, which is a method for forming at least one of a fiber container and a paper pulp container.

19. A container obtainable from or obtainable by a manufacturing method comprising the method described in claim 16.

20. The container is at least one of a fiber container and a paper pulp container, and is obtainable or obtainable from the manufacturing method described in claim 19.

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