Manufacturing method for water-soluble unit dose article

Abstract

To prevent a water-soluble unit dose article from sticking together after completion.SOLUTION: In a manufacturing method for a water-soluble unit dose article in which a fixed amount of a water-soluble article is individually packaged, an individual package is formed in which the fixed amount of the water-soluble article is covered with a water-soluble film. In a heating and drying device that generates an air current by introducing hot air, the individual package is heated and dried in an area that is not directly hit by the hot air immediately after the introduction.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a method for producing a water-soluble unit dose article in which a measured amount of a water-soluble substance is individually packaged. [Background technology]

[0002] Patent Document 1 discloses a water-soluble unit-dose product in which a fixed amount of laundry detergent is individually packaged in a water-soluble film. This water-soluble unit-dose product allows consumers to pour a fixed amount of laundry detergent into a washing machine together with the water-soluble film without having to measure it out themselves when using the laundry detergent, providing great convenience for daily laundry. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-013873 Summary of the Invention [Problem to be solved by the invention]

[0004] After the water-soluble unit dose articles are completed, one or more water-soluble unit dose articles must be prepared for shipment, for example, by packaging them in a box. In this preparation process, handling multiple water-soluble unit dose articles together can save costs and time. However, handling multiple water-soluble unit dose articles together can cause the water-soluble films constituting each water-soluble unit dose article to stick together, which can cause problems during the process.

[0005] The present invention aims to prevent water-soluble unit-dose articles from sticking together after completion. [Means for solving the problem]

[0006] In one embodiment of the present invention, a method for producing a water-soluble unit-dose article in which a predetermined amount of a water-soluble substance is individually packaged includes forming an individual package in which a predetermined amount of the water-soluble substance is covered with a water-soluble film. In a heating and drying device that generates an air current by introducing hot air, the individually wrapped bodies are heated and dried in an area that is not directly hit by the hot air immediately after the introduction. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent the water-soluble unit-dose articles from sticking together after completion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a water-soluble unit dose article according to one embodiment of the present invention. [Figure 2] 1 is a flowchart showing the flow of producing the water-soluble unit dose article. [Figure 3] FIG. 1 is a schematic diagram showing a line for producing the water-soluble unit dose article. [Figure 4] 3 is a flowchart showing step S1 in FIG. 2. [Figure 5] FIG. 5 is a schematic diagram showing step S11 in FIG. 4. [Figure 6] FIG. 5 is a schematic diagram showing step S12 in FIG. 4. [Figure 7] FIG. 5 is a schematic diagram showing step S13 in FIG. 4. [Figure 8] FIG. 5 is a schematic diagram showing step S14 in FIG. 4. [Figure 9] FIG. 5 is a schematic diagram showing step S15 in FIG. 4. [Figure 10] FIG. 5 is a schematic diagram showing step S16 in FIG. 4. [Figure 11] FIG. 3 is a schematic diagram showing step S2 in FIG. 2. [Figure 12] FIG. 3 is a schematic diagram showing step S3 in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Configuration of Water-Soluble Unit Dose Article 10] 1, a water-soluble unit-dose article 10 according to one embodiment of the present invention is configured in a stick shape and includes a water-soluble substance 11, a first water-soluble film 12a, and a second water-soluble film 12b. In the water-soluble unit-dose article 10, the water-soluble substance 11 constitutes the contents, and the water-soluble films 12a and 12b constitute the packaging material.

[0010] The water-soluble unit-dose article 10 further has a heat-sealed portion 13. The heat-sealed portion 13 is provided around the entire periphery of the edge of the laminated water-soluble films 12a, 12b, and the water-soluble films 12a, 12b are heat-sealed to each other. In the water-soluble unit-dose article 10, a water-soluble substance 11 is contained in the region between the water-soluble films 12a, 12b, inside the heat-sealed portion 13.

[0011] Water-soluble unit-dose article 10 is a product in which a certain amount of water-soluble substance 11 required for one use is individually packaged in water-soluble films 12a, 12b. When used, water-soluble unit-dose article 10 is immersed in water, whereby water-soluble films 12a, 12b, which are the packaging materials, dissolve, releasing water-soluble substance 11 into the water.

[0012] Powdered laundry detergent is an example of the water-soluble substance 11. In a water-soluble unit-dose article 10 in which the water-soluble substance 11 is a laundry detergent, the longitudinal dimension can be approximately 100 mm, the width dimension can be approximately 20 mm, and the height dimension can be approximately 12 mm, for example.

[0013] In the water-soluble unit-dose article 10, the water-soluble substance 11 can be composed of not only laundry detergent but also powder, granular, or block-like substances. The shape of the water-soluble unit-dose article 10 is not limited to a stick shape, and can be any three-dimensional shape, such as a sphere, a rectangular parallelepiped, or a flat plate.

[0014] An example of the water-soluble films 12a and 12b is a water-soluble PVA film containing water-soluble polyvinyl alcohol (PVA) as a main component. The water-soluble films 12a and 12b are not limited to water-soluble PVA films, and may be, for example, films formed from any water-soluble resin.

[0015] In the water-soluble unit-dose article 10 according to one embodiment of the present invention, the adhesiveness of the outer surfaces of the water-soluble films 12a, 12b is suppressed after completion. This makes it easier to handle multiple water-soluble unit-dose articles 10 together after completion, especially in the shipping preparation process that is carried out immediately after completion. The flow of the manufacturing process and shipping preparation process for the water-soluble unit-dose article 10 according to this embodiment will be described below.

[0016] [Process for making and preparing for shipment of water-soluble unit-dose article 10] (Summary) Fig. 2 shows a flow of the manufacturing process and shipping preparation process of the water-soluble unit-dose article 10. In the flow shown in Fig. 2, steps S1 to S4 constitute the manufacturing process of the water-soluble unit-dose article 10, and step S5 constitutes the shipping preparation process of the water-soluble unit-dose article 10. In other words, the manufacturing method of the water-soluble unit-dose article 10 according to this embodiment includes steps S1 to S4.

[0017] Figure 3 shows a schematic diagram of a line that continuously performs the steps of producing and preparing for shipment of water-soluble unit-dose articles 10. Figure 3 shows areas D1 to D5 connected by a series of conveyors C. Areas D1 to D5 correspond to steps S1 to S5 shown in Figure 2, respectively. In other words, steps S1 to S5 are performed sequentially in areas D1 to D5.

[0018] (Step S1: Forming individual packages) Overall structure In step S1, an individual package 20 is formed by an individual package forming apparatus 100 arranged in area D1. The individual package 20 is an individual package of a water-soluble substance 11 before it becomes a product, and will become a water-soluble unit-dose article 10 through subsequent steps S2 to S4. Step S1 includes steps S11 to S16 shown in FIG. 4. The individual package forming apparatus 100 has a mold M.

[0019] 5 to 10 show a vertical cross section of a mold M used to form the individual packaging body 20. The mold M is provided with a plurality of recesses M1 and a plurality of holes M2. Each recess M1 is groove-shaped and opens upward, extending in the front-to-back direction of the page. Each hole M2 is configured as a through-hole that penetrates between the lower surface of the mold M and the bottom surface of each recess M1.

[0020] In the mold M, each recess M1 is used to form one individual package 20. The mold M shown in Fig. 5 is provided with two recesses M1, making it possible to simultaneously form two individual packages 20. In the mold M, the number of recesses M1 can be determined arbitrarily, and by increasing the number of recesses M1, it is possible to increase the number of individual packages 20 that can be simultaneously formed.

[0021] In step S1, large uncut water-soluble films 12a and 12b are used. The water-soluble films 12a and 12b used in step S1 may have different configurations, for example, may be made of different resins, or may have different thicknesses.

[0022] The water-soluble films 12a and 12b are generally stored in a controlled environment with low humidity to prevent wrinkles and stickiness. However, in step S1, the processability of the water-soluble films 12a and 12b is likely to be insufficient if the humidity is the same as that during storage. For this reason, step S1 is preferably performed in a humidified atmosphere to improve the processability of the water-soluble films 12a and 12b. This increases the flexibility of the water-soluble films 12a and 12b, which, for example, allows for smoother transport of the water-soluble films 12a and 12b and smoother vacuum suction of the first water-soluble film 12a in step S12 described below.

[0023] For example, for the water-soluble films 12a and 12b made of water-soluble PVA film, it is preferable that the humidity during storage is 35% to 45% and that in step S1 is 50% to 55%. Note that it is not essential that all steps in step S1 be performed in a humidified atmosphere, but it is preferable that at least some steps be performed in a humidified atmosphere.

[0024] Step S11: Preheating The individual package forming apparatus 100 further includes a heater H used in step S11. In step S11, as shown in Fig. 5, the first water-soluble film 12a is placed on the upper surface of the mold M so as to cover the multiple recesses M1 from above all at once. Then, the heater H is placed above the first water-soluble film 12a, facing the first water-soluble film 12a, and the first water-soluble film 12a is heated by the heater H.

[0025] This increases the temperature of the first water-soluble film 12a, causing the first water-soluble film 12a to soften on the mold M. As an example, for the first water-soluble film 12a made of a water-soluble PVA film, the preheating temperature in step S11 is preferably 154°C or higher and 174°C or lower.

[0026] Step S12: Vacuuming 6, in step S12, a vacuum is drawn from the area below the mold M using a vacuum pump, and the air inside the recess M1 is discharged through the hole M2 to the underside of the mold M. As a result, the first water-soluble film 12a softened in step S11 is sucked into the recess M1 and adheres to the inner surface of the recess M1 by vacuum suction.

[0027] In the subsequent steps S13 to S15, in order to maintain the state in which the first water-soluble film 12a is constrained on the inner surface of the recess M1, it is necessary to maintain a reduced pressure in the region below the mold M. For this reason, in the subsequent steps S13 to S15, the evacuation of the region below the mold M may be continued following step S12, or the evacuation may be stopped while maintaining the reduced pressure in the region below the mold M using a check valve of the vacuum pump or the like.

[0028] Step S13: Filling In step S13, as shown in FIG. 7, the water-soluble substance 11 is filled into the recess M1 in the mold M, the recess M1 having the first water-soluble film 12a attached to its inner surface.

[0029] Step S14: Heat welding 8, in step S14, the second water-soluble film 12b that closes the recess M1 of the mold M is supplied onto the upper surface of the mold M, while the pair of welding surfaces Y of the water-soluble films 12a, 12b are heat-welded onto the upper surface of the mold M. The individual package forming apparatus 100 further has a water supply roller R1, a direction changing roller R2, and a heating roller R3 that are used in step S14.

[0030] It is preferable to add moisture to the water-soluble films 12a and 12b from the viewpoints of improving processability and enhancing the sealing properties of the heat-sealed portion 13. Therefore, in step S14 of this embodiment, it is preferable to wet the welding surface Y of the second water-soluble film 12b with water using a water supply roller R1. Next, in order to make the angle at which the second water-soluble film 12b enters the mold M gentler, the conveying direction of the second water-soluble film 12b is changed by a direction-changing roller R2.

[0031] Then, the first water-soluble film 12a and the second water-soluble film 12b supplied onto the mold M are sandwiched between the heated heating roller R3 and the upper surface of the mold M, thereby thermally welding the pair of welding surfaces Y of the water-soluble films 12a and 12b together. This forms a thermally welded portion 13 where the water-soluble films 12a and 12b are thermally welded together.

[0032] In step S14, the welding surface Y of the second water-soluble film 12b is wetted with water by the water supply roller R1, thereby improving processability. This allows stable heat welding even when the temperature of the heating roller R3 is lower than when the film is not wetted with water. By performing heat welding at a lower temperature, deterioration of the water-soluble films 12a and 12b is less likely to occur, thereby stabilizing the quality of the water-soluble unit-dose article 10.

[0033] In step S14, the welding surface Y may be the first water-soluble film 12a side, or both the water-soluble films 12a and 12b side. The method for wetting the welding surfaces Y of the water-soluble films 12a and 12b with water in step S14 is not limited to the method using the water supply roller R1, and any known method may be selected.

[0034] As an example, when the water-soluble films 12a and 12b are water-soluble PVA films, the heat welding temperature suitable for heat welding is normally in the range of 160° C. to 180° C., but by wetting the welding surface Y with water, the temperature is lowered to the range of 110° C. to 130° C. In other words, in this embodiment, the temperature of the heating roller R3 can be lowered by about 50° C.

[0035] In this embodiment, it is preferable to perform a hole-forming step of forming small holes in the second water-soluble film 12b after step S14 and before step S15, so that if the water-soluble films 12a and 12b shrink in steps S03 and S04, for example, the air in the space containing the water-soluble substance 11 can smoothly escape through the holes.

[0036] The perforation step can be carried out, for example, by perforating with a needle. The diameter (thickness) of the needle used for perforation is preferably 0.35 mm or more and 0.65 mm or less. The needle tip during perforation may be oriented vertically downward (so as to pierce the second water-soluble film 12b perpendicularly). However, when perforation is performed while the mold M is being transported, the needle tip is preferably oriented obliquely downward, tilted forward in the transport direction of the mold M, to prevent damage to the second water-soluble film 12b. In this case, the angle between the needle tip during perforation and the transport direction of the mold M is preferably 20° or more and 60° or less, more preferably 30° or more and 45° or less.

[0037] Step S15: Cutting The individual package forming apparatus 100 further includes a cutter B used in step S15. In step S15, as shown in Fig. 9, the cutter B cuts the heat-sealed portions 13 on the upper surface between the plurality of recesses M1 in the mold M, thereby separating the water-soluble films 12a and 12b. As a result, individual packages 20 are obtained for each of the plurality of recesses M1 in the mold M.

[0038] As cutter B used in step S15, it is preferable to use a fusion cutter that fuses and cuts the water-soluble films 12a and 12b with its cutting edge heated. As an example, when the water-soluble films 12a and 12b are water-soluble PVA films, it is preferable to set the temperature of the cutting edge of cutter B in step S15 to 186°C or higher and 206°C or lower.

[0039] Step S16: Eject 10, in step S16, the area below the mold M is opened to the atmosphere to release the reduced pressure, allowing air to enter the recess M1 from the bottom side through the hole M2, thereby releasing the first water-soluble film 12a from being constrained to the inner surface of the recess M1, thereby enabling the individual package 20 to be removed from the recess M1.

[0040] In step S16, the recessed portion M1 of the mold M, which has been released from the constraint on the first water-soluble film 12a, is placed on the conveyor C and faces downward, allowing the plurality of individual packages 20 to fall freely all at once onto the conveyor C. The plurality of individual packages 20 that have fallen freely onto the conveyor C are transported by the conveyor C as is to area D2.

[0041] (Step S2: Condition adjustment) In step S2, the state of the plurality of individual packages 20 on the conveyor C in area D2 is adjusted. In step S2, at least the stacked state in which the individual packages 20 are stacked one on top of the other is resolved, and typically the individual packages 20 are aligned with their longitudinal direction facing the direction of travel. This makes it possible to prevent the plurality of individual packages 20 from sticking together.

[0042] Step S2 is performed while the plurality of individual packages 20 being conveyed by conveyor C passes through area D2. Adjustment of the state of the plurality of individual packages 20 in step S2 may be performed manually, automatically using a device, or may be performed by a combination of both manual and mechanical methods.

[0043] For example, in step S2, a device including a curtain-like sheet hanging down from above onto the conveyor C can be used. In this device, the lower end of the sheet is positioned slightly higher than the height of the individual packages 20 on the conveyor C, and of the individual packages 20 stacked one on top of the other, only the upper individual package 20 comes into contact with the sheet and receives a pressing force, thereby eliminating the stacked state.

[0044] (Step S3: Heat drying) In step S3, the individual packages 20 are passed through an internal space P with a high-temperature atmosphere in region D3 to heat and dry the individual packages 20. Step S3 is performed to improve the handleability of the water-soluble unit-dose article 10 in step S5.

[0045] Although the water-soluble films 12a and 12b are stored under low humidity conditions, they often become highly sticky after molding because they absorb moisture during the molding process (step S1) of the individual package 20 or are wetted with water to improve processability.

[0046] Therefore, when the individual packages 20 come into contact with each other, the water-soluble films 12a, 12b that make up each individual package 20 are likely to stick together. For this reason, if the individual packages 20 are to be used as a product as is, it is necessary to perform the steps in step S5 so that the individual packages 20 do not come into contact with each other.

[0047] In contrast, in step S3, the individual package 20 is passed through an internal space P with a high-temperature atmosphere, thereby heating and drying the water-soluble films 12a, 12b that make up the individual package 20. As a result, moisture is removed from the wet water-soluble films 12a, 12b in the individual package 20, and the moisture content approaches that of the water-soluble films 12a, 12b during storage (temperature: 25°C, humidity: 35% to 45%), eliminating stickiness. This completes the water-soluble unit-dose article as a product.

[0048] 11 shows a cross section of the heating drying apparatus 200 that can be used in step S3, taken along line A-A' in FIG. 3. The heating drying apparatus 200 has a box-shaped main body 210 that forms an internal space P. A plurality of introduction holes 211 are provided in the side wall of the main body 210. The heating drying apparatus 200 is configured to introduce hot air into the internal space P through the plurality of introduction holes 211 in the main body 210. That is, in the heating drying apparatus 200, the internal space P becomes a space with a high-temperature atmosphere during operation.

[0049] For example, the heating drying device 200 can be configured so that air heated by a heater provided on the main body 210 is sent along the outer surface of the main body 210 to the side wall portion and introduced into the internal space P through the multiple introduction holes 211. The introduced heated air is preferably in a dry state with low humidity. Note that the heating drying device 200 may use other known configurations for introducing hot air into the internal space P through the multiple introduction holes 211.

[0050] In the heating and drying device 200, hot air introduced from the inlet holes 211 of the main body 210 generates an air current that circulates in the internal space P, thereby maintaining a uniform temperature in the internal space P. In the heating and drying device 200, the plurality of individual packages 20 on the conveyor C are efficiently and uniformly heated by heat transfer due to forced convection as they pass through the air current in the internal space P.

[0051] In the heating and drying device 200, the multiple introduction holes 211 are all provided at a position higher than the area on the conveyor C in the internal space P through which the multiple individual packages 20 pass. Therefore, in the heating and drying device 200, there are no individual packages 20 in the direction of travel of the hot air immediately after it is introduced into the internal space P through the multiple introduction holes 211.

[0052] For this reason, in the heating and drying device 200, the hot air immediately after being introduced does not directly hit the individual packages 20 while the individual packages 20 on the conveyor C are passing through the internal space P. This makes it possible to prevent the occurrence of poor appearance (partial whitening) due to localized temperature increases in the water-soluble films 12a, 12b caused by the hot air directly hitting the individual packages 20.

[0053] The temperature of the air forming the airflow in the high-temperature atmosphere internal space P in step S3 is preferably determined so that the adhesiveness of the outer surfaces of the water-soluble films 12a, 12b is eliminated and no significant shrinkage occurs. As an example, when the water-soluble films 12a, 12b are water-soluble PVA films, the temperature of the air forming the airflow in step S3 is preferably 140°C or higher and 160°C or lower. In addition, the humidity of the air forming the airflow is preferably lower than 55%, more preferably lower than 45%, and even more preferably lower than 35%.

[0054] Furthermore, the time during which the individual packages 20 pass through the internal space P with a high-temperature atmosphere in step S3 is preferably 10 seconds or more and 30 seconds or less. The time during which the individual packages 20 pass through the internal space P with a high-temperature atmosphere in step S3 can be controlled, for example, by the transport speed of the conveyor C. The transport speed of the conveyor C in step S3 can be set to, for example, 100 mm / sec.

[0055] (Step S4: Cooling) In step S4, the individual packages 20 are cooled by the cooling device 300 arranged in area D4. Step S4 is carried out while the plurality of individual packages 20 being conveyed by the conveyor C passes through the cooling device 300. Step S4 is carried out following step S3 in order to quickly cool the individual packages 20 whose temperature has been raised in step S3.

[0056] In step S4, the shape retention of the water-soluble films 12a, 12b is improved by quickly cooling the individual packages 20. Furthermore, step S4 shortens the time during which the water-soluble films 12a, 12b are softened, making it less likely that the individual packages 20 will be deformed. These factors make it easier to obtain water-soluble unit-dose articles 10 with good appearance.

[0057] Furthermore, since the water-soluble unit-dose article 10 obtained in step S4 has cooled to a temperature that can be touched by hand, step S5 can be started immediately after step S4. Furthermore, step S4 eliminates the need for a waiting space for allowing the water-soluble unit-dose article 10 to cool naturally after step S3, allowing the equipment to be made more compact.

[0058] 12 shows a cross section of cooling device 300 that can be used in step S4, taken along line B-B' in FIG. 3. Cooling device 300 has a box-shaped main body 310 that forms an internal space Q. A plurality of air vents 311 are provided in the upper wall of main body 310. Cooling device 300 is a room-temperature air-cooling device configured to introduce outside air into internal space Q through the plurality of air vents 311 in main body 310.

[0059] As an example, cooling device 300 can be configured so that outside air is introduced into internal space Q by fans provided in multiple air vents 311. In cooling device 300, the air introduced from multiple air vents 311 facing above conveyor C directly hits individual packages 20 on conveyor C, so that individual packages 20 can be cooled efficiently.

[0060] In cooling device 300, air introduced through multiple air blowing holes 311 in main body 310 generates an air current that circulates through internal space Q, thereby making it possible to maintain a uniform temperature in internal space Q. In cooling device 300, multiple individual packages 20 on conveyor C are efficiently and uniformly cooled by heat transfer due to forced convection as they pass through the air current in internal space Q.

[0061] In step S4, since outside air is introduced directly into the internal space Q of the cooling device 300, the temperature of the air forming the airflow in the internal space Q is at or near room temperature. More specifically, in step S4, the temperature of the air forming the airflow in the internal space Q of the cooling device 300 is preferably set to 10°C or higher and 40°C or lower.

[0062] In step S4, the lower the temperature in the internal space Q of the cooling device 300, the shorter the cooling time for the individual packages 20, but the more likely it is that condensation will cause the outer surfaces of the water-soluble films 12a, 12b to become sticky again. For this reason, in step S4, it is preferable not to use a cooler or the like to cool the air introduced into the internal space Q of the cooling device 300 to a temperature lower than room temperature. Furthermore, it is preferable that the temperature difference between the temperature of the air introduced into the internal space Q of the cooling device 300 and the temperature of the outer surfaces of the water-soluble films 12a, 12b be kept at 20°C or less throughout the entire process, and preferably 10°C or higher at the beginning of introduction.

[0063] Furthermore, the cooling time for the individual packaging body 20 in step S4 is preferably 10 seconds or more and 30 seconds or less. The cooling time for the individual packaging body 20 in step S4 can be controlled, for example, by the transport speed of the conveyor C. The transport speed of the conveyor C in step S4 can be set to, for example, 100 mm / sec.

[0064] This completes the production of the water-soluble unit-dose article 10 of this embodiment. In this embodiment, since the water-soluble unit-dose article 10 obtained in step S4 has been cooled to a temperature that allows it to be easily handled by hand, step S5 can be performed immediately after step S4 to prepare the water-soluble unit-dose article 10 for shipment.

[0065] (Step S5: Packaging) In step S5, the water-soluble unit-dose articles 10 on the conveyor C are packed into boxes in area D5. Step S5 is the first step in the shipping preparation process. In step S5, the water-soluble unit-dose articles 10 on the conveyor C are packed sequentially into boxes such as cardboard boxes so that a large number of water-soluble unit-dose articles 10 can be transported efficiently together.

[0066] Packaging the water-soluble unit-dose articles 10 into boxes in step S5 is typically performed manually, but may also be performed automatically using a machine, or may be performed using a combination of manual and machine processes. In step S5, it is advantageous from the standpoint of efficiency to pack a plurality of water-soluble unit-dose articles 10 together in a stacked state.

[0067] In this regard, in this embodiment, as described above, the adhesiveness of the water-soluble films 12a, 12b of the water-soluble unit-dose articles 10 on the conveyor C that have been transported to area D5 has been eliminated, so even if multiple water-soluble unit-dose articles 10 are stacked and handled, the water-soluble films 12a, 12b are less likely to stick together, and step S5 can be carried out smoothly.

[0068] Step S5 may be any step performed immediately after step S4, and is not limited to a boxing step. For example, step S5 may be a collective packaging step in which a predetermined number of water-soluble unit-dose articles 10 are collectively packaged in an outer bag. Even in the collective packaging step, efficient collective packaging is possible by handling a plurality of water-soluble unit-dose articles 10 in a stacked manner.

[0069] [Other embodiments] Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and that various modifications can be made.

[0070] For example, step S1 does not have to be performed in a humidified atmosphere if the water-soluble films 12a, 12b can be sufficiently processed without humidification, such as when the humidity is originally between 50% and 55%. Also, when step S1 is performed in a room with a humidity of more than 55%, it is preferable to perform it in a dehumidified atmosphere.

[0071] In step S14, for example, if the heat welding temperature of the water-soluble films 12a, 12b can be reduced by another means, the welding surfaces Y of the water-soluble films 12a, 12b do not need to be wetted with water. In step S14, the heating roller R3 does not need to be used, and a known heating member such as a heating plate with a smooth heating surface may be used.

[0072] Furthermore, the cooling device 300 used in step S4 may not have a main body 310, i.e., the periphery of the conveyor C may be open and may be equipped with a device for blowing air onto the individual packages 20. In this embodiment, step S4 may not be performed if there is no process to be performed immediately after step S3 or if a waiting space can be secured for allowing the water-soluble unit-dose article 10 to cool naturally after step S3. [Explanation of symbols]

[0073] 10...Water-soluble unit dose articles 11...Water-soluble substances 12a...First water-soluble film 12b...Second water-soluble film 13…Heat welding part 20…Individual packaging 100...Individual package forming equipment 200…Heating drying device 210...Main unit 211...Inlet hole 300…Cooling device 310...Main unit 311...Air vent D1~D5…area M...mold M1...recess M2…hole H...Heater B...Cutter R1~R3...Roller P,Q…Internal space

Claims

1. 1. A method for producing a water-soluble unit dose article in which a measured amount of a water-soluble material is individually packaged, comprising: forming an individual package in which the water-soluble substance is covered with a water-soluble film; In a heating and drying device that generates an air current by introducing hot air, the individually wrapped body is heated and dried in an area that is not directly hit by the hot air immediately after the introduction. Methods for producing water-soluble unit dose articles.

2. The step of forming the individual package includes a step of heat-sealing the water-soluble films together, and a step of wetting at least one of the pair of welded surfaces of the water-soluble films with water before heat-sealing. A method for producing the water-soluble unit dose article of claim 1.

3. At least a part of the step of forming the individual packages is carried out in a humid atmosphere. A method for producing the water-soluble unit dose article of claim 1 or 2.

4. the water-soluble film is a water-soluble PVA film, The temperature of the air forming the airflow in the step of heating and drying the individual packages is 140°C or higher and 160°C or lower. A method for producing the water-soluble unit dose article of claim 1 or 2.

5. the water-soluble film is a water-soluble PVA film, The heat welding temperature in the step of heat welding the water-soluble films together is 110°C or higher and 130°C or lower. A method for producing the water-soluble unit dose article of claim 2.

6. After the step of heating and drying the individual packages, the individual packages are cooled in an air stream. A method for producing the water-soluble unit dose article of claim 1 or 2.

7. In the step of cooling the individual packages, the air forming the airflow is not cooled to a temperature lower than room temperature. A method for producing the water-soluble unit dose article of claim 6.

8. The step of heating and drying the individual packages and the step of cooling the individual packages are carried out in the process of transporting the individual packages on a series of conveyors. A method for producing the water-soluble unit dose article of claim 6.

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