Absorbent core for a reusable diaper and reusable diaper

Abstract

Absorbent core (1) for a reusable diaper (100) which is manufactured using a flat knitting process, comprising an upper and a lower layer (2, 4) between which an intermediate layer (6) is arranged, characterized in that the intermediate layer (6) has hollow fibers (8) and the upper and lower layers (2, 4) are connected to each other by binding points (10, 12).

Description

[0001] The invention relates to an absorbent core for a reusable diaper and a reusable diaper.

[0002] Hygiene products for holding and absorbing urine and stool are generally well-known. Disposable products, especially single-use diapers, and reusable diapers are frequently used in infant and child care, as well as by adults.

[0003] Disposable diapers are pre-shaped, folded, and have a liquid-permeable inner layer, an absorbent non-woven material made of cotton, viscose, or polyester, a superabsorbent core, and a waterproof outer layer that is partially breathable. With reusable diapers, absorbency is typically achieved through various inserts made of different materials. To achieve the desired absorbency, several inserts must be combined, depending on the child's age and the amount of urine produced. This makes the diapers very bulky and can restrict the child's freedom of movement.

[0004] With conventional cloth diapers, stool is often collected by a separate fleece liner. This liner usually has to be disposed of via the toilet or with the regular trash.

[0005] From WO 2022 / 069 950 A1, a suction core is known which can be produced using the flat knitting method and has an upper and lower layer, between which an intermediate layer is arranged.

[0006] From DE 295 04 038 U1 a diaper is known which consists of a fabric, wherein an absorbent core is sewn to the fabric layer.

[0007] Viscose fiber is described at https: / / de.wikipedia.org / wiki / Viskosefaser.

[0008] The object of the present invention is to provide an absorbent core and a reusable diaper whose handling is improved while optimizing sustainability.

[0009] According to a first aspect of the invention, this problem is solved by an absorbent core with the features of claim 1. Such an absorbent core is reusable. In particular, it can be machine washed and dried. The intermediate layer embedded between the upper and lower layers, which has hollow fibers, is designed to be particularly absorbent. The absorbent core according to the invention is particularly easy to produce on a flat knitting machine. The absorbent core can be knitted into its three-dimensional shape directly on the flat knitting machine. No further processing steps are necessary. Such an absorbent core according to the invention can also be combined with existing reusable cloth diapers.

[0010] The upper and lower layers are joined together by tie-off points. These tie-off points can be created during knitting on a flat knitting machine. The tie-off points essentially fix the intermediate layer in place. This prevents the hollow fibers from accumulating in specific spots, which would result in other areas of the intermediate layer having virtually no hollow fibers. The tie-off points ensure that the hollow fibers remain evenly distributed throughout the intermediate layer. A quilting effect can be achieved through the tie-off points. This quilting can be diamond-shaped or circular, and especially elliptical. In particular, several concentric ellipses can be formed by the tie-off points.

[0011] Further advantages arise when the hollow fibers are viscose fibers. Viscose hollow fibers are particularly absorbent.

[0012] The intermediate layer may also contain natural fibers, in particular nettle, bast, and / or cotton fibers, and / or synthetic fibers, in particular polyester. Additionally, standard viscose fibers (that are not hollow fibers) may be included. These may have a ribbed surface, which improves water distribution within the intermediate layer. The fibers of the intermediate layer may be arranged, in particular, within a flyer wick.

[0013] The upper layer of the absorbent core can be double-knitted, with the side facing away from the intermediate layer using a different yarn than the side facing the intermediate layer. The choice of yarn can thus influence the function of the absorbent core. In particular, a yarn that is especially skin-friendly can be used on the upper layer, as this layer comes into contact with a child's skin, while the opposite side of the layer can be tailored to the function of the intermediate layer.

[0014] It has proven particularly advantageous when the side facing away from the intermediate layer is knitted from a natural fiber yarn, especially wool, and the side facing the intermediate layer is made from viscose yarn. In particular, wool can be plated with viscose. This combination of materials protects a child's skin from moisture buildup. The wool does not feel wet. The viscose plating further increases the absorbency of the intermediate layer.

[0015] The top layer of the absorbent core can be made of wool with a superwash finish. This means the wool is hydrophobic (dry against the skin). Wool is also antibacterial and skin-friendly. Viscose, on the other hand, is suitable for wicking away liquid. The knit structure of the top and bottom layers can be chosen to promote liquid wicking.

[0016] The bottom layer of the absorbent core can be knitted from a synthetic fiber yarn, especially polyester yarn. This allows for quick drying after washing. The bottom layer can also be welded to a liquid-tight layer or coating, if desired.

[0017] The invention also encompasses a reusable diaper with a knitted section comprising an absorbent core according to the invention. A front and back waistband can be knitted onto the absorbent core. The absorbent core can therefore be an integral part of the reusable diaper. Such a diaper is significantly thinner than a comparable known cloth diaper and, due to the absorbent core, as absorbent as a disposable diaper. As a rule, no additional absorbent core or other insert needs to be placed in the diaper to achieve sufficient absorbency.

[0018] Because the reusable diaper is knitted using a flat knitting process, no waste is produced during its manufacture. In particular, the various parts of the reusable diaper, especially the knitted section, do not need to be cut. The knitted section can be knitted into shape. Only a waterproof outer layer, which will be described later, is cut and welded on.

[0019] The knitted part of the reusable diaper can be produced, in particular, on a flat knitting machine using insert knitting technology. The diaper incorporates different materials, depending on the requirements. These materials can be selectively inserted at defined points with a defined bond during the flat knitting process.

[0020] The diaper according to the invention is particularly thin. Using flat knitting technology, selected yarns are processed into a knitted fabric. This allows for the flexibility to incorporate the right yarns at any point. The front and back waistbands can be knitted from cotton. Cotton also has comfortable wearing properties. Furthermore, the waistband can contain elastane.

[0021] The front and / or back waistband can have areas of varying elasticity. The elasticity of these areas can be adjusted during the knitting process. In particular, a central elastic area can be incorporated, followed by less elastic, especially inelastic, areas. The elasticity can be adjusted by knitting in an elastane yarn.

[0022] The front and back waistbands can have fastening elements. In particular, these fastening elements can be components of a hook-and-loop fastener, especially hook and loop tape. Alternatively, snap fasteners can be provided. This feature allows the reusable diapers to be used not only as diapers but also as underwear. Furthermore, the fastening elements allow the waistband to be adjusted, so the diaper "grows" with the child.

[0023] The absorbent core can have knitted side edges made of a synthetic fiber yarn, especially polyester. These side edges can be used to weld the knitted part to a waterproof outer layer, particularly using ultrasonic welding. This eliminates the need for seams that would lead to leaks.

[0024] The diaper can have a waterproof outer layer. In particular, the outer layer can have a breathable membrane. The breathable membrane can be permeable to water vapor. The outer layer can be selected to withstand several wash cycles without losing its waterproofness. Preferably, the outer layer is not fully bonded to the knitted part. This improves the diaper's drying properties after washing. Preferably, the outer layer can be welded to the knitted part. In particular, the outer layer can be welded to the aforementioned side edges knitted from synthetic yarn.

[0025] Elasticated cuffs made of plastic can be welded to the absorbent core, particularly to the side edges knitted from synthetic yarn. This prevents leakage of the diaper in the leg area. Additionally, a cuff, especially a coated fabric band, can be attached in the hip area to prevent feces from leaking out. The coating can be made of polyurethane.

[0026] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, with reference to the figures in the drawing, which show essential details of the invention, and from the claims. The features shown therein are not necessarily to scale and are depicted in such a way that the inventive features are clearly visible. The various features can be implemented individually or in any combination in variants of the invention.

[0027] The schematic drawing shows exemplary embodiments of the invention, which are explained in more detail in the following description.

[0028] They show: Fig. 1 a schematic cross-sectional view through a suction core; Fig. 2. A top view of the inside of a reusable diaper after a first manufacturing step; Fig. 3 a top view of the inside of the finished diaper; Fig. 4. A view of the outside of the diaper during manufacturing; Fig. 5. An external view of the finished diaper; Fig. 6 a cross-sectional view through a finished diaper in the area of ​​the absorbent core; Fig. 7 Another cross-sectional view of the finished diaper.

[0029] The Fig. Figure 1 shows an absorbent core 1 comprising an upper layer 2 and a lower layer 4. An intermediate layer 6 is arranged between the upper layer 2 and the lower layer 4. The intermediate layer 6 comprises hollow fibers 8, in particular viscose hollow fibers. Natural fibers, such as nettle fibers, bast fibers, or cotton fibers, may also be included. The fibers of the intermediate layer 6 may be bundled together to form a flyer wick. Additionally or alternatively, synthetic fibers, such as polyester, acrylic, or polyamide, may be included.

[0030] The upper layer 2 and the lower layer 4 are connected to each other by binding points 10 and 12. This secures the position of the fibers in the intermediate layer 6.

[0031] The upper layer 2 can be made of wool plated with viscose on the reverse side, particularly on the side facing the intermediate layer 6. Alternatively, the upper layer 2 can also be made of a different material. The lower layer 4 can be made of synthetic yarn, particularly polyester yarn. The entire absorbent core 1 is manufactured using a flat knitting process on a flat knitting machine. After production on the flat knitting machine, the absorbent core 1 does not require any finishing.

[0032] The Fig. Figure 2 shows a diaper 100, in particular a view of the inside of a knitted part 102 of the diaper 100. The knitted part 102 has an absorbent core 1 to which a waistband 104, 106 is knitted at the top and bottom. The waistband 104, 106 is preferably made of cotton and particularly preferably also knitted with elastane. An elastic section 108, 110 with an elastic weave is provided in each case. Sections 112, 114 with a firm weave, i.e., inelastic sections, adjoin the section 108. Fastening elements, such as the parts of a hook-and-loop fastener, can be attached to the sections 112, 114.

[0033] The side edges 120, 122 of the absorbent core 1 are knitted from a synthetic fiber yarn, in particular polyester. The transition areas 124, 126 to the hip bands 104, 106 can also be knitted from a synthetic fiber yarn. This allows these areas to be subsequently welded to an outer cover, which will be described later.

[0034] The side edges 120, 122 are adjoined by outer cuffs 121, 123, which serve as leg cuffs. The outer cuffs 121, 123 can also be knitted. They preferably contain elastane.

[0035] The entire knitting section 102, as it appears in the Fig. The component shown in Figure 2 can be produced in this form on a flat knitting machine. There is no material waste. No finishing or joining steps are necessary. In particular, the knitted part 102 can be produced as a three-dimensional shaped knitted piece.

[0036] It is indicated that the setting points 10 and 12 create a diamond pattern. Setting points 10 and 12 can also be arranged in other patterns, for example as concentric ellipses.

[0037] The Fig. Figure 3 shows a top view of the inside of the finished diaper. It can be seen that leak-proof cuffs 130, 132, 133, made of polyester or a fabric with elastic yarn, have been welded to the side edges 120, 122 and the transition area 124, primarily using ultrasonic welding. The cuff 133 is designed to prevent feces from leaking out. Hook-and-loop fasteners 134, 136 are also shown as fastening elements.

[0038] The Fig. Figure 4 shows a top view of the outside of the knitted part 102. In particular, the lower layer 4, made of a synthetic fiber yarn, especially polyester, is now on top, while in the Fig. 3 the upper layer 2 was on top. The remaining sections of the knitted part 102 were in connection with the Fig. 2 has already been described, so only the corresponding reference numbers need to be inserted. Furthermore, a hook and loop fastener 139 can be identified as a fastening element, which interacts with hook and loop fasteners 134 and 136.

[0039] The Fig. Figure 5 shows a top view of the completed diaper 100, in particular a top view of the outer surface. It can be seen that an outer layer 140 was attached to the knitted part 102. The outer layer 140 was welded to the side edges 120, 122 according to the welds 142, 144 and to the welds 143, 145. To ensure a good seal against the legs of a child wearing the diaper 100, outer cuffs 146, 148 with elastic thread were incorporated into the edge area.

[0040] The Fig. Figure 6 shows a longitudinal section through the diaper 100 according to the Fig. 5. Here it can be seen that the outer layer 140 has a membrane 150 that is permeable to water vapor. The outer layer 140 is welded to the waistband 104, 106 at the weld seams 143, 145.

[0041] In the cross-sectional view of the Fig. Figure 7 shows that the outer layer 140 has an incorporated rubber thread 148. Only one absorbent yarn is visible. The absorbent yarn is inserted from left to right.

Claims

[1] Absorbent core (1) for a reusable diaper (100) manufactured by flat knitting, comprising an upper and a lower layer (2, 4) between which an intermediate layer (6) is arranged, characterized by , that the intermediate layer (6) has hollow fibers (8) and the upper and lower layers (2, 4) are connected to each other by setting points (10, 12). [2] Suction core according to one of the preceding claims, characterized by , that the hollow fibers (8) are formed as viscose fibers. [3] Suction core according to one of the preceding claims, characterized by , that the intermediate layer (6) continues to contain natural fibers, in particular nettle, bast, and / or cotton fibers, and / or synthetic fibers, in particular polyester. [4] Suction core according to any one of the preceding claims, characterized by, that the upper layer (4) is knitted on both sides, the side facing away from the intermediate layer (6) having a different yarn than the side facing the intermediate layer (6). [5] Suction core according to claim 4, characterized by , that the side facing away from the intermediate layer (6) is knitted from a natural fiber yarn, in particular wool, and the side facing the intermediate layer (6) is made from viscose yarn. [6] Suction core according to any one of the preceding claims, characterized by , that the lower layer (4) is knitted from a synthetic fiber yarn, in particular polyester yarn. [7] Reusable diaper (100) with a knitted part (102) comprising an absorbent core (1) according to any of the preceding claims. [8] Reusable diaper according to claim 7, wherein a front and rear waistband (104, 106) are knitted onto the absorbent core (1). [9] Reusable diaper according to claim 8, characterized by, that the front and back waistband (104, 106) are knitted from cotton. [10] Reusable diaper according to one of the preceding claims 8 or 9, characterized by , that the front and / or back waistband (104, 106) has areas of different elasticity. [11] Reusable diaper according to any one of the preceding claims 8 to 10, characterized by , that the front and rear waistband (104, 106) have fastening elements. [12] Reusable diaper according to any one of the preceding claims 7 to 11, characterized by , that the absorbent core (1) made of a synthetic fiber yarn, in particular polyester, has knitted side edges (120, 122). [13] Reusable diaper according to any one of the preceding claims 7 to 12, characterized by , that the diaper (100) has a waterproof outer layer (140). [14] Reusable diaper according to any one of the preceding claims 7 to 13, characterized by, that the outer layer (140) includes a breathable membrane (150). [15] Reusable diaper according to one of the preceding claims 13 or 14, characterized by , that the outer layer (140) is welded to the knitted part (102). [16] Reusable diaper according to any one of the preceding claims 7 to 15, characterized by , that elastic cuffs (130, 132) made of plastic are welded to the absorbent core (1).

Images