Woven core for sanitary materials, weaving method, and absorbent sanitary article

Abstract

The application discloses a woven core for sanitary materials, which comprises, from top to bottom, an upper surface layer, an intermediate spacing layer and a lower surface layer; the upper surface layer is knitted by upper surface layer yarns, the lower surface layer is knitted by lower surface layer yarns, and the intermediate spacing layer is formed by intermediate layer yarns which pass through the upper surface layer and the lower surface layer multiple times; the intermediate layer yarns form connecting points when passing through the upper surface layer and the lower surface layer; the upper surface layer yarns, the lower surface layer yarns and the intermediate layer yarns are respectively formed by one fiber filament or spun by several fiber filaments; wherein the intermediate layer yarns comprise at least one yarn, the number of fiber filaments spun to form the yarn is less than the number of fiber filaments spun to form the upper surface layer yarns and the lower surface layer yarns, and the fewer the types of yarns constituting the intermediate layer yarns and the fewer the fiber filaments spun to form the yarns, the better; the basis weight of the woven core is 30-500 gsm, and the thickness is 0.1-15 mm. The woven core of the application exhibits excellent compression deformation rate, resilience and return seepage inhibition rate.

Description

Technical Field

[0001] This invention relates to a disposable absorbent sanitary product and the woven core used therein and the weaving method thereof. More specifically, this invention relates to a woven core for sanitary materials, the weaving method thereof, and absorbent sanitary products using the woven core. Background Technology

[0002] Disposable absorbent hygiene products such as sanitary napkins, diapers, and incontinence protectants generally consist of a top sheet, a back sheet, and an absorbent core structure facing the wearer during use. The top sheet is liquid-permeable, while the back sheet is liquid-impermeable. The absorbent core structure is typically thin and compressed, often containing a large amount of highly absorbent agent, such as a superabsorbent polymer resin. However, its absorption rate is often insufficient to instantly absorb large amounts of liquid, such as urine, expelled within seconds, leading to leakage and embarrassing situations. To address this, WO2009105000 A1 discloses an absorbent hygiene product that incorporates a liquid storage layer. This layer can rapidly receive large amounts of liquid and temporarily store it before it is absorbed by the absorbent structure. This liquid storage function is typically achieved through a woven core.

[0003] When absorbent sanitary products are worn, they are subjected to a certain amount of pressure, which can compress the product. It has been estimated that the pressure exerted on the center of an absorbent sanitary product, such as the center of an absorbent pad, is approximately 2-5 kPa when standing or walking, approximately 10-20 kPa when sitting, 30 kPa when sitting and leaning forward, and as high as 50 kPa when cycling. To maintain good fluid distribution within the absorbent sanitary product, the fabric core needs to withstand a certain amount of pressure.

[0004] Chinese invention patent CN 201280078034.1 discloses an absorbent article having a spacer fabric as a fluid flow control component. The absorbent article involved in this patent can be a personal hygiene article, which includes a liquid-permeable top sheet, a liquid-impermeable back sheet, an absorbent core surrounded between the top sheet and the back sheet, and a fluid flow control component arranged between the top sheet and the back sheet. The fluid flow control component is a spacer fabric with a basis weight of 150-300 gsm and includes a top layer and a bottom layer and an interconnecting layer of pile fibers between the top layer and the bottom layer. The pile fibers have a fineness of 80-130 dtex and a density of 50-150 pile fiber connection points / cm2.

[0005] Chinese utility model patent CN 202220661116.X (publication number CN 218774002U) discloses an environmentally friendly and breathable sanitary core made of hydrophilic fibers. It includes a core body and fixing fibers for shaping the core body. This sanitary core is not shaped by adhesives or heat sealing, but rather by fixing the fibers. Chinese utility model patent CN202220846654.6 (publication number CN 218356569U) discloses a sanitary core including a core body with downwardly extending funnel-shaped drainage holes on its upper surface. These funnel-shaped drainage holes allow blood to quickly reach the bottom layer of the core, thus diffusing between the layers.

[0006] Chinese utility model patent CN 202222274669.2 (publication number CN 218084576U) discloses a low-reflow core nonwoven fabric, which is composed of structural layer A (1), structural layer B (2), structural layer C (3), and structural layer D (4); structural layer A (1) is set on the top layer, structural layer D (4) is set on the bottom layer, and structural layer B (2) is set between structural layer A (1) and structural layer D (4); structural layer A (1), structural layer B (2), and structural layer D (4) are laid in order from top to bottom; structural layer A (1), structural layer B (2), and structural layer D (4) are laid in order from top to bottom; Layer B(2) and structural layer D(4) are connected through structural layer C(3); structural layer C(3) passes through structural layers A(1), B(2), and D(4) and entangles them together; structural layer A(1) is a wet-laid spunlace composite nonwoven fabric, consisting of an absorbent layer (5) and a fiber web layer (6) laid in order from top to bottom; structural layer D(4) is a spunlace composite nonwoven fabric, consisting of a diffusion layer (7) and a leak-proof layer (8) laid in order from top to bottom. The core is composed of spunlace composite nonwoven fabric, SAP super absorbent resin, and hot melt adhesive, belonging to the field of nonwoven fabrics, and is a four-layer structure. The upper and lower layers are spunlace composite nonwoven fabrics, the middle layer contains SAP super absorbent resin, and the layers are interwoven and entangled by hot melt adhesive.

[0007] There are two main types of cores used in existing sanitary products: cotton cores and composite cores. However, both types of cores have some problems and are not very suitable for use in sports care products. Cotton cores are thick and heavy, prone to linting, have low wet strength, clump and deform after absorbing liquid, and are prone to moisture reabsorption; composite cores are thick and heavy, prone to powdering, have low wet strength, and are prone to moisture reabsorption.

[0008] The absorbent article disclosed in the aforementioned invention patent CN201280078034.1, which has a spacer fabric as a fluid flow control component, has a liquid-impermeable backing sheet, which hinders the liquid from permeating from the upper layer to the lower layer, and it also lacks the ability to control the directional difference of liquid diffusion in the horizontal direction. Furthermore, the cores disclosed in the aforementioned utility models CN 218774002U, CN218356569U, and CN 218084576U are difficult to maintain a certain elasticity after absorbing liquid, and have a large compression deformation rate.

[0009] Therefore, in view of the problems existing in the prior art, it is necessary to provide a woven core for sanitary materials with better compression deformation rate, elasticity and backflow control rate, so that the woven core can still maintain its original shape after absorbing liquid and has better compression deformation rate and elasticity. Summary of the Invention

[0010] The purpose of this invention is to provide a woven core with better compression set and elasticity, and absorbent sanitary products using the woven core.

[0011] To achieve the aforementioned objectives, the present invention provides a woven core for sanitary materials, comprising, from top to bottom, an upper surface layer, an intermediate spacer layer, and a lower surface layer. The upper surface layer is woven from upper surface layer yarns, the lower surface layer is woven from lower surface layer yarns, and the intermediate spacer layer is formed by the intermediate layer yarns passing through the upper and lower surface layers multiple times. The intermediate layer yarns form connection points when passing through the upper and lower surface layers. The upper surface layer yarn, the lower surface layer yarn, and the intermediate layer yarn are each formed by a single fiber filament or spun from several fiber filaments. The intermediate layer yarn forming the intermediate spacer layer comprises at least one type of yarn, and the number of fiber filaments spun into this yarn is lower than the number of fiber filaments spun into the upper surface layer yarn and the number of fiber filaments spun into the lower surface layer yarn. Furthermore, the fewer the types of yarns constituting the intermediate layer yarn, the fewer the fiber filaments spun into this yarn. The basis weight of the resulting woven core can be 30-500 gsm, and the thickness is 0.1-15 mm.

[0012] The woven core of the sanitary material of the present invention, due to the use of an intermediate layer yarn with a smaller number of fibers, has greater strength (mechanical strength) than yarn with a larger number of fibers under the same fineness, thus the elasticity of the entire woven core is better; even when the fineness of the intermediate layer yarn is small, if the number of fibers spun into the yarn is small enough, for example, 1-5, its strength is still relatively large, thus the elasticity of the entire woven core is still good. Thus, to obtain a highly elastic woven core, the yarn in the intermediate spacer layer can be of a suitable fineness. This has the advantage of significantly reducing the overall basis weight of the woven core, for example, to below 100 gsm, such as 30-63 gsm, thereby reducing the manufacturing cost. Furthermore, due to the use of finer intermediate spacer layer yarns, the resulting woven core still exhibits considerable softness even at higher bond point densities. The higher bond point density, in turn, ensures that the woven core retains excellent compression set and elasticity even when using finer intermediate layer yarns. Simultaneously, because finer intermediate layer yarns are used, it is not required that the fineness of the intermediate layer yarns be greater than that of the upper and lower surface layer yarns, thus maintaining appropriate pore size in both layers. With finer intermediate layer yarns, a higher bond point density will not affect the flow efficiency of fluid in the intermediate spacer layer; on the contrary, it will suppress backflow.

[0013] In the woven core of the present invention, the fineness of the intermediate layer yarn used does not exceed 150D, or even 75D, so that the size of the holes formed when it passes through the upper and lower surface layers is more suitable and backflow is less likely to occur.

[0014] In the woven core of the present invention, by controlling the number of fibers contained in the intermediate layer yarn, the strength and fineness of the intermediate spacer layer yarn are affected. The control of fineness will affect the size of the holes formed when the intermediate spacer layer yarn passes through the upper and lower surface layers and the density of the connection points, thereby affecting the flow efficiency of the fluid in the intermediate spacer layer.

[0015] Therefore, in this invention, the number of fibers contained in the interlayer yarn can be used to adjust the compression deformation rate and elasticity of the woven core, so as to overcome the defect of simply increasing the elasticity by increasing the fineness of the interlayer yarn in the prior art.

[0016] In fact, in the woven core of the present invention, when the fineness of the intermediate layer yarn is the same, the compression set and elasticity can be adjusted to a certain extent by controlling the number of fibers forming the intermediate layer yarn. With the same fineness and material, the fewer fibers spun into the yarn, the higher the hardness or stiffness of the resulting yarn, and thus the better the compression set and elasticity of the resulting intermediate spacer layer. Preferably, in the present invention, the number of fibers (filaments) forming the intermediate layer yarn does not exceed 48, 36, 24, or 12.

[0017] In one specific embodiment of the present invention, the number of fibers forming the intermediate layer yarn is a single fiber. In this case, the fineness of the intermediate layer yarn can be relatively small, for example, it can be 40D. A appropriately small fineness of the intermediate layer yarn can, on the one hand, reduce the cost of the intermediate layer yarn, and on the other hand, increase the softness of the entire woven core, without needing to reduce the fineness of the upper and / or lower layer yarns.

[0018] Preferably, in the woven core of the present invention, the fineness of the upper surface yarn and the fineness of the lower surface yarn can be controlled between 30D and 150D respectively.

[0019] Preferably, the intermediate layer yarns used include at least two types of yarns with different finenesses. More preferably, among the various intermediate layer yarns, the finer yarns are spun from a larger number of fibers, while the finer yarns are spun from a smaller number of fibers. The inventors have discovered that this technical solution has a surprisingly good trade-off effect on the product's compression set, elasticity, etc.

[0020] As a specific embodiment of the woven core of the present invention, in the intermediate layer yarns used, the fineness of the finer yarn is at least no greater than one of the fineness of the upper surface layer yarn and the fineness of the lower surface layer yarn.

[0021] Furthermore, in the intermediate layer yarns used, the finer yarns are finer than both the upper and lower layer yarns, and the number of fibers spun into them is less than both the number of fibers spun into the upper and lower layer yarns.

[0022] As a specific embodiment of the woven core of the present invention, the fineness of the upper surface yarn and the fineness of the lower surface yarn are respectively between 30D and 150D.

[0023] In another specific embodiment of the present invention, the upper and / or lower surface layers of the woven core can be fluffy, for example, by pulling out yarn or by friction to obtain a fluffy surface layer.

[0024] In this invention, the term "disposable" means something that is discarded after limited use without being cleaned or repaired for reuse.

[0025] In this invention, the basis weight of the entire woven core is preferably 30-500 gsm, more preferably 30-200 gsm; and its thickness, measured without pressure, is preferably 0.5-6 mm, more preferably 1-4 mm.

[0026] In this invention, the fibers used in each yarn include thermoplastic polymer fibers, preferably selected from, but not limited to, polyester, polyamide, and polyolefins, such as polyethylene and polypropylene, or mixtures thereof. The layers of the yarn or woven core may also include (e.g., coated) surfactants to promote liquid penetration so that it can be rapidly drained without retaining any liquid, thereby maintaining free volume for subsequent outflows. Preferably, the yarns of the upper layer, the lower layer, and the middle layer are polyester.

[0027] On the other hand, in order to achieve the objective of this invention, this invention also provides a method for preparing the above-mentioned woven core, wherein the woven core comprises, from top to bottom, an upper surface layer, an intermediate spacer layer, and a lower surface layer; wherein:

[0028] (1) The upper layer is woven from the upper layer yarn, the lower layer is woven from the lower layer yarn, and the middle interlayer is formed by the middle layer yarn passing through the upper and lower layers multiple times.

[0029] (2) The intermediate layer yarn forms a connection point when it passes through the upper surface layer and the lower surface layer;

[0030] (3) A weaving needle is used for each of the yarns used for weaving the upper surface layer and the yarns used for weaving the lower surface layer.

[0031] (4) The yarns used to weave the intermediate spacer layer include at least two types of yarns with different fineness and different numbers of fibers;

[0032] (5) In the intermediate layer of the braid (which may be all 30D / 1F or part of 30D / 1F), at least some of the two or more yarns with different fineness and different number of fibers share the same weaving needle, and the remaining yarns are each matched with a weaving needle.

[0033] (4) When weaving the upper layer, the lower layer and the middle layer, the weaving composition and proportion of the yarns of the upper layer, the lower layer and the middle layer are controlled as follows: each independent yarn of each layer comes from an independent yarn ball and can be separated from the yarns from other yarn balls.

[0034] Furthermore, in order to achieve the objective of this invention, this invention also provides an absorbent sanitary product comprising the aforementioned woven core.

[0035] In this invention, absorbent hygiene products can be sanitary napkins, diapers, nursing pads, or other forms of products.

[0036] As a specific embodiment of the absorbent sanitary product of the present invention, the absorbent sanitary product may include a liquid-permeable top sheet, a liquid-impermeable bottom sheet, an absorbent core surrounding the top sheet and the bottom sheet, and the aforementioned flow control member disposed between the top sheet and the bottom sheet.

[0037] The woven core of the present invention, by optimizing the fineness of the intermediate layer yarn and the number of fibers forming the intermediate layer yarn, enables the woven core to exhibit excellent softness, compression set, elasticity, and backflow inhibition rate, and can better control product costs.

[0038] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. However, these specific embodiments are merely descriptions of certain specific implementations of the present invention and are not intended to limit the present invention. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of a woven core for sanitary materials according to a specific embodiment of the present invention; wherein, the upper and lower layers of the woven core each use 24 sets of 30D / 36F yarn, and the middle spacer layer uses 24 sets of 50D / 36F yarn and 4 sets of 30D / 1F yarn, wherein the 4 sets of 50D / 36F yarn and the 4 sets of 30D / 1F yarn share the same weaving needle. The remaining yarns are each equipped with a weaving needle; Figure 1 In this embodiment, 1 is the upper layer of the woven core, 3 is the lower layer of the woven core, and 30D / 36F yarn is used in both; 2 is the middle layer of the woven core, 4 is 50D / 36F yarn, and 5 is 30D / 1F yarn. In this embodiment, four sets of 50D / 36F yarn and four sets of 30D / 1F yarn share the same weaving needle.

[0040] Figure 2 This is a schematic diagram of the structure of a woven core for sanitary materials according to another specific embodiment of the present invention; wherein, the upper and lower layers of the core are each made of 24 sets of 30D / 36F yarn, and the intermediate spacer layer is made of 20 sets of 50D / 36F yarn and 4 sets of 30D / 1F yarn. Each yarn is equipped with a weaving needle; in the figure, 1 is the upper layer of the woven core, 3 is the lower layer of the core, 2 is the middle layer of the woven core, 6 is 30D / 1F yarn, 7 is 50D / 36F yarn, and each yarn is equipped with a weaving needle;

[0041] Figure 3This is a schematic diagram of the structure of a woven core for sanitary materials in another specific embodiment of the present invention; wherein, the upper and lower layers of the woven core for sanitary materials each use 24 sets of 50D / 72F yarn, and the middle spacer layer uses 12 sets of 50D / 36F yarn and 12 sets of 30D / 1F yarn. In the figure, the meanings of the reference numerals are as follows: 8 is the upper layer of the woven core, 9 is the lower layer of the woven core, 2 is the middle layer of the woven core, 6 is 30D / 1F yarn, 7 is 50D / 36F yarn, and each yarn is matched with a weaving needle; Detailed Implementation

[0042] The implementation and use of various embodiments of the present invention are discussed in detail below. However, it should be understood that the specific embodiments discussed are merely illustrative of particular ways of implementing and using the present invention, and are not intended to limit the scope of the invention. In the description, the structural positions of various components, such as upper, lower, top, bottom, etc., are not absolute but relative. These directional descriptions are appropriate when the various components are arranged as shown in the figures, but these directional descriptions also change accordingly when the positions of the various components in the figures change.

[0043] Example 1

[0044] Please refer to Figure 1 In this embodiment of the invention, the woven core comprises, from top to bottom, an upper surface layer 1, an intermediate spacer layer 2, and a lower surface layer 3. The upper and lower layers each use 24 sets of 30D / 36F yarn, while the intermediate spacer layer uses 24 sets of 50D / 36F yarn and 4 sets of 30D / 1F yarn, wherein the 4 sets of 50D / 36F yarn and the 4 sets of 30D / 1F yarn share the same weaving needle. The remaining yarns are each paired with a weaving needle. The intermediate spacer layer is formed by the intermediate layer yarns passing through the upper and lower surface layers multiple times; each time the intermediate layer yarns pass through the upper and lower surface layers, a connection point is formed.

[0045] In this embodiment, the intermediate layer yarn includes a 50D yarn and a 30D yarn, wherein the fineness of the 30D yarn is no greater than that of the 30D yarn in the upper and lower layers; the density of the connection points is approximately 400 per cm. 2 The number of fibers forming the 30D yarn in the middle layer is a single fiber, which is less than the 36 fibers forming the upper and lower surface layers, respectively. The basis weight of the entire woven core is 80-120 gsm, and the thickness is approximately 1.5-2.2 mm.

[0046] Example 2

[0047] Please refer to Figure 2In this embodiment of the present invention, the woven core B includes: 1 as the upper layer of the woven core, 3 as the lower layer of the core, 2 as the middle layer of the woven core, 6 as 30D / 1F yarn, 7 as 50D / 36F yarn, and each yarn is equipped with a weaving needle.

[0048] In this embodiment, the intermediate layer yarn has two types: 50D / 36F yarn and 30D / 1F yarn, which are respectively connected to the upper surface layer 30D / 36F yarn D and the lower surface layer 30D / 36F yarn; the density of the connection points is approximately 460 per cm. 2 The number of fibers forming the intermediate layer yarn is 1 and 3 respectively; the number of fibers forming the upper layer yarn and the number of fibers forming the lower layer yarn are both 36. The basis weight of the entire woven core is 70-110 gsm, and the thickness is about 1.8 mm.

[0049] Example 3

[0050] Please refer to Figure 3 In this embodiment of the invention, the upper and lower layers of the sanitary material core each use 24 sets of 50D / 72F yarn, and the intermediate spacer layer uses 12 sets of 50D / 36F yarn and 12 sets of 30D / 1F yarn. Figure 3 In the diagram, 8 represents the upper layer of the woven core, 9 represents the lower layer, 2 represents the middle layer, 6 represents 30D / 1F yarn, and 7 represents 50D / 36F yarn. Each yarn is paired with a weaving needle. The entire woven core has a basis weight of 110-150 gsm and a thickness of approximately 1.8-2.0 mm.

[0051] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A woven core for sanitary materials, comprising, from top to bottom, an upper surface layer, an intermediate spacer layer, and a lower surface layer; the upper surface layer is woven from upper surface layer yarns, the lower surface layer is woven from lower surface layer yarns, and the intermediate spacer layer is formed by intermediate layer yarns passing through the upper surface layer and the lower surface layer multiple times; the intermediate layer yarns form connection points when passing through the upper surface layer and the lower surface layer; the upper surface layer yarns, the lower surface layer yarns, and the intermediate layer yarns are each formed from a single fiber filament or spun from several fiber filaments; characterized in that... The intermediate layer yarn comprises at least one type of yarn, the number of fibers spun into this yarn being lower than the number of fibers spun into the upper surface layer yarn and the number of fibers spun into the lower surface layer yarn, and the fewer the types of yarns constituting the intermediate layer yarn, the fewer the fibers spun into this yarn; the basis weight of the woven core is 30-500 gsm, and the thickness is 0.1-15 mm.

2. The woven core as described in claim 1, characterized in that, The intermediate layer yarn comprises at least two types of yarns with different numbers of fiber filaments.

3. The woven core as described in claim 1 or 2, characterized in that, The intermediate layer yarn comprises at least two types of yarn with different fineness.

4. The woven core as described in claim 3, characterized in that, In the intermediate layer yarn, there are more fibers that are spun into finer yarns, and fewer fibers that are spun into finer yarns.

5. The woven core as described in claim 4, characterized in that, In the intermediate layer yarns, the finer yarns are at least no finer than either the fineness of the upper layer yarns or the fineness of the lower layer yarns.

6. The woven core as described in claim 5, characterized in that, In the intermediate layer yarn, the finer yarn is finer than both the upper and lower layer yarns, and the number of fibers it produces is less than both the number of fibers produced in the upper and lower layer yarns.

7. The woven core as described in any one of claims 1-6, characterized in that, The fineness of the upper surface yarn and the fineness of the lower surface yarn are respectively between 30D and 150D.

8. A method for weaving a woven core as described in any one of claims 1-7, wherein the woven core comprises, from top to bottom, an upper surface layer, an intermediate spacer layer, and a lower surface layer; wherein: (1) The upper layer is woven from the upper layer yarn, the lower layer is woven from the lower layer yarn, and the intermediate spacer layer is formed by the intermediate layer yarn passing through the upper layer and the lower layer multiple times; (2) The intermediate layer yarn forms a connection point when it passes through the upper surface layer and the lower surface layer; (3) Each of the yarns used for weaving the upper surface layer and the yarns used for weaving the lower surface layer is equipped with a weaving needle; (4) The yarns used to weave the intermediate spacer layer include at least two types of yarns with different fineness and different numbers of fibers; (5) In the weaving of the intermediate spacer layer, at least some of the two or more yarns with different fineness and different number of fibers share the same weaving needle, and the remaining yarns are each matched with a weaving needle.

9. An absorbent sanitary product, characterized in that, The absorbent hygiene product includes a woven core as described in any one of claims 1-7.

10. The absorbent sanitary product as claimed in claim 9, characterized in that, The absorbent sanitary product includes a liquid-permeable top sheet, a liquid-impermeable bottom sheet, an absorbent core surrounding the top sheet and the bottom sheet, and the woven core disposed between the top sheet and the bottom sheet.

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