Viscose fiber absorption core body and preparation method thereof

Abstract

The invention discloses a viscose absorption core and a preparation method thereof, and relates to the field of sanitary materials. The viscose fiber absorption core body comprises a first spunlace viscose fiber layer, a first adhesive layer, a first flexible layer, an absorption core layer, a second flexible layer, a second adhesive layer and a second spunlace viscose fiber layer which are sequentially arranged, the first spunlace viscose fiber layer and the second spunlace viscose fiber layer are prepared from viscose fibers through a spunlace process; the first flexible layer and the second flexible layer are viscose fiber layers which are not spunlaced, and the viscose fiber layers which are not spunlaced are obtained after viscose fibers are opened and carded into viscose fiber nets. The viscose fiber absorption core body has the advantages of being good in flexibility, high in diffusion and absorption speed, good in air permeability, good in reverse osmosis resistance and stable in structure, and the use comfort of a user can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sanitary materials, in particular to a viscose fiber absorbent core and a preparation method thereof. BACKGROUND

[0002] In the field of sanitary products, medical care products and the like, the absorbent core as a core functional component directly affects the use experience and environmental protection characteristics of the product. The upper and lower surfaces of the traditional absorbent core are usually made of a non-woven fabric layer of polyester or polypropylene synthetic fiber prepared by a melt-blown process to realize liquid conduction and structural support. However, such synthetic fiber materials have obvious defects: on the one hand, they have poor softness and are easy to produce a rough feeling when in contact with the human body, reducing the use comfort; on the other hand, the hydrophilicity and liquid diffusion and permeability of polyester and polypropylene materials are limited, and liquid is easy to form aggregation on the surface of the core, thereby causing reverse osmosis problems and poor use comfort. SUMMARY

[0003] In order to improve the problem of poor use comfort of the absorbent core in the related art, the present application provides a viscose fiber absorbent core and a preparation method thereof.

[0004] In a first aspect, the present application provides a viscose fiber absorbent core using the following technical solution: A viscose fiber absorbent core, comprising a first spunlace viscose fiber layer, a first adhesive layer, a first flexible layer, an absorbent core layer, a second flexible layer, a second adhesive layer and a second spunlace viscose fiber layer arranged in sequence. The first spunlace viscose fiber layer and the second spunlace viscose fiber layer are prepared by water jetting process of viscose fiber. The first flexible layer and the second flexible layer are both unspunlace viscose fiber layers, and the unspunlace viscose fiber layer is obtained by opening and carding the viscose fiber into a viscose fiber web.

[0005] The upper and lower surfaces of the traditional absorbent core are usually made of a non-woven fabric layer of polyester or polypropylene material prepared by a melt-blown process, and the present application uses a spunlace viscose fiber layer to replace the traditional polyester or polypropylene non-woven fabric layer. Compared with the traditional polyester or polypropylene non-woven fabric layer, the spunlace viscose fiber layer (i.e. the first spunlace viscose fiber layer and the second spunlace viscose fiber layer) of the present application has better softness, rapid diffusion and permeability, and air permeability, and also has biodegradability, which is conducive to improving the use comfort and reducing the reverse osmosis problem.

[0006] Secondly, the absorbent core of the present application further comprises a first flexible layer and a second flexible layer, the first flexible layer and the second flexible layer are viscose fiber layers obtained by opening and carding viscose fibers, the viscose fiber layers have better bulkiness and softness, and can also be beneficial to the stable adhesion of the absorbent core layer, without the need to additionally increase the adhesive layer between the first flexible layer or the second flexible layer and the absorbent core layer, and can promote the rapid diffusion and absorption of liquid, and is beneficial to further improving the comfort.

[0007] In addition, in order to improve the structural stability between the first water-jet viscose fiber layer and the first flexible layer, and between the second water-jet viscose fiber layer and the second flexible layer, the present application increases a first adhesive layer between the first water-jet viscose fiber layer and the first flexible layer, and a second adhesive layer between the second water-jet viscose fiber layer and the second flexible layer.

[0008] In summary, the viscose fiber absorbent core of the present application has the advantages of good softness, fast diffusion and absorption speed, good air permeability, good anti-back seepage, and structural stability, which is beneficial to improving the use comfort of users.

[0009] In some specific embodiments, the viscose fibers are modified viscose fibers using amino silane coupling agents, the first adhesive layer and the second adhesive layer are prepared from styrene block copolymer, tackifier, plasticizer, silane coupling agent modified talc powder, and peroxide initiator with a weight ratio of (35-45):(25-35):(15-25):(7.4-8.3):(0.1-0.2); The silane coupling agent modified talc powder is obtained by jointly modifying talc powder with alkenyl silane coupling agent and epoxy silane coupling agent.

[0010] In the present application, the viscose fibers for preparing the first / second water-jet viscose fiber layer and the first / second flexible layer are preferably modified viscose fibers using amino silane coupling agents, and the first adhesive layer and the second adhesive layer respectively add an appropriate amount of silane coupling agent modified talc powder obtained by jointly modifying talc powder with alkenyl silane coupling agent and epoxy silane coupling agent, which can react with the double bond in the hot melt adhesive powder through the alkenyl group on the silane coupling agent modified talc powder, thereby improving the dispersibility and bonding stability of the silane coupling agent modified talc powder in the hot melt adhesive powder, and at the same time, the epoxy group on the silane coupling agent modified talc powder reacts and bonds with the amino group in the first / second water-jet viscose fiber layer and the first / second flexible layer, which is beneficial to further improving the stability between the first water-jet viscose fiber layer and the first flexible layer, and between the second water-jet viscose fiber layer and the second flexible layer. At the same time, in the present application, the thickness of the first adhesive layer and the second adhesive layer can be as low as 1-2 μm, which can improve the structural stability of the absorbent core while taking into account the air permeability of the absorbent core.

[0011] In some specific embodiments, the amino silane coupling agent modified viscose fibers are made from the amino silane coupling agent and the viscose fibers in a weight ratio of (0.1-0.2):5, and the weight ratio of the alkenyl silane coupling agent, the epoxy silane coupling agent and the talc in the silane coupling agent modified talc is (0.15-0.2):(0.3-0.4):10.

[0012] In the present application, the weight ratio of the amino silane coupling agent and the viscose fibers and the weight ratio of the alkenyl silane coupling agent, the epoxy silane coupling agent and the talc are controlled within the above ranges, which is beneficial to further improve the structural stability of the absorbent core while taking into account the air permeability.

[0013] In some specific embodiments, the alkenyl silane coupling agent is at least one of vinyl trimethoxysilane, vinyl tri(2-methoxyethoxy)silane and vinyl triethoxysilane.

[0014] In some specific embodiments, the absorbent core layer comprises wood pulp fibers and high polymer water-absorbing resin particles.

[0015] In the present application, the absorbent core layer comprises wood pulp fibers and high polymer water-absorbing resin particles, wherein the wood pulp fibers have a porous network structure and can rapidly absorb liquid by capillary action and quickly disperse it to the entire core area, preventing the problem of local liquid accumulation leading to leakage, which is beneficial to improve dryness and reduce the feeling of dampness. The high polymer water-absorbing resin particles can absorb several tens or even hundreds of times their own weight of liquid and lock it firmly in the network molecular structure to form a hydrogel, effectively storing and shrinking water, and maintaining water under pressure without backflow and reverse osmosis, ensuring dryness of the skin contact surface.

[0016] In some specific embodiments, the thickness of the absorbent core layer is 1.8-2.5 mm, wherein the mass percentage of the wood pulp fibers is 35-45%, and the mass percentage of the high polymer water-absorbing resin particles is 55-65%.

[0017] In some specific embodiments, the first and second spunlace viscose fiber layers are obtained by sequentially opening, carding the viscose fibers into a viscose fiber web, 90° cross-laying the viscose fiber web, drawing, spunlacing and drying the viscose fibers; in the spunlacing step, the spunlacing pressure is sequentially 20-30 bar, 40-50 bar and 80-100 bar.

[0018] In the present application, the first / second spunlace viscose fiber web layer is laid in 90° cross-laying, breaking the one-way arrangement of fibers, making the network structure isotropic, which is conducive to improving the dimensional stability, and the multi-directional fiber network can accelerate liquid diffusion; the spunlace pressure is divided into three gradients, 20-30 bar is conducive to the preliminary fixation of fiber position to prevent displacement caused by direct high pressure impact, 40-50 bar is conducive to forming the main network skeleton and improving the basic strength, and 80-100 bar is conducive to realizing the permanent entanglement between fibers, which can improve the structural stability of the first / second spunlace viscose fiber web layer.

[0019] In some specific embodiments, the areal density of the viscose fiber web is 35-45 g / m 2 ; when the viscose fiber web is laid in 90° cross-laying, the number of viscose fiber webs is 6-8.

[0020] In some specific embodiments, in the drawing step, the draw ratio is 2-2.5 times.

[0021] In the second aspect, the present application provides a preparation method of a viscose fiber absorbent core body, which adopts the following technical scheme: A preparation method of a viscose fiber absorbent core body, comprising the following steps: Rolling the first adhesive layer on the surface of the first spunlace viscose fiber layer, then covering the first flexible layer on the surface of the first adhesive layer, then forming the absorbent core layer on the surface of the first flexible layer, and covering the second flexible layer on the surface of the absorbent core layer to obtain a preformed core body; rolling the second adhesive layer on the surface of the second spunlace viscose fiber layer, then covering the second adhesive layer on the surface of the second flexible layer of the preformed core body, and pressing to obtain a viscose fiber absorbent core body.

[0022] In summary, the present application at least includes the following beneficial technical effects: (1) The application adopts a spunlace viscose fiber layer to replace the traditional polyester or polypropylene non-woven fabric layer. Compared with the traditional polyester or polypropylene non-woven fabric layer, the spunlace viscose fiber layer (i.e. the first spunlace viscose fiber layer and the second spunlace viscose fiber layer) of the application has better softness, rapid diffusion permeability and air permeability, and also has biodegradability, which is conducive to improving the use comfort and reducing the reverse osmosis problem. Secondly, the absorbent core of the application also increases the first flexible layer and the second flexible layer. The first flexible layer and the second flexible layer are viscose fiber layers obtained by opening and carding viscose fibers. The viscose fiber layer has better bulkiness and softness, and can also be conducive to the stable adhesion of the absorbent core layer. There is no need to additionally increase the adhesive layer between the first flexible layer or the second flexible layer and the absorbent core layer, and it can promote the rapid diffusion and absorption of liquid, which is conducive to further improving the comfort. In addition, in order to improve the structural stability between the first spunlace viscose fiber layer and the first flexible layer, and between the second spunlace viscose fiber layer and the second flexible layer, the application increases the first adhesive layer between the first spunlace viscose fiber layer and the first flexible layer, and the second adhesive layer between the second spunlace viscose fiber layer and the second flexible layer.

[0023] (2) In the application, the viscose fibers for preparing the first / second spunlace viscose fiber layer and the first / second flexible layer are preferably amino silane coupling agent modified viscose fibers, and the first adhesive layer and the second adhesive layer respectively add an appropriate amount of silane coupling agent modified talc powder obtained by jointly modifying talc powder with alkenyl silane coupling agent and epoxy silane coupling agent. The alkenyl group on the silane coupling agent modified talc powder can react with the double bond in the hot melt adhesive powder, thereby improving the dispersibility and combination stability of the silane coupling agent modified talc powder in the hot melt adhesive powder. At the same time, the epoxy group on the silane coupling agent modified talc powder can react and bond with the amino group in the first / second spunlace viscose fiber layer and the first / second flexible layer, which is conducive to further improving the stability between the first spunlace viscose fiber layer and the first flexible layer, and between the second spunlace viscose fiber layer and the second flexible layer. At the same time, in the application, the thickness of the first adhesive layer and the second adhesive layer can be as low as 1-2 μm, which can improve the structural stability of the absorbent core while taking into account the air permeability of the absorbent core. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the viscose fiber absorbent core of the application.

[0025] BRIEF DESCRIPTION OF DRAWINGS 1, first spunlace viscose fiber layer; 2, first adhesive layer; 3, first flexible layer; 4, absorbent core layer; 5, second flexible layer; 6, second adhesive layer; 7, second spunlace viscose fiber layer. DETAILED DESCRIPTION

[0026] The application will be further described below in combination with specific experiments.

[0027] Preparation Example Preparation Example 1-1 The spunlace viscose fiber layer is prepared as follows: Step 1, the viscose fiber (Fuhui, dry breaking strength 2.15 CN / dtex) is sequentially opened and carded into a viscose fiber web with a surface density of 40 g / m 2 ; Step 2, 7 viscose fiber webs are sequentially subjected to 90° cross-laying, and after laying, drawing is performed with a draw ratio of 2 times, followed by water jetting and drying to obtain a spunlace viscose fiber layer. In the water jetting step, water jetting is performed using water jetting pressures of 25 bar, 450 bar and 88 bar in sequence.

[0028] Preparation Example 1-2 The spunlace viscose fiber layer is prepared as follows: 0.15 kg of silane coupling agent KH550 is added to 100 kg of 95% mass concentration ethanol aqueous solution, and after stirring and dissolving uniformly, 5 kg of viscose fiber is added, and the temperature is raised to 45-50°C for reaction, followed by filtration, washing and drying to obtain amino silane coupling agent modified viscose fiber.

[0029] Preparation Example 2-1 The flexible layer is the viscose fiber web prepared in Step 1 of Preparation Example 1-1.

[0030] Preparation Example 2-2 The flexible layer is the viscose fiber web prepared in Step 1 of Preparation Example 1-2.

[0031] Preparation Example 3-1 A hot melt adhesive particle is obtained by melt extrusion, granulation and cooling of styrene-isoprene-styrene copolymer (Baliny petrochemical brand 1105), C5 / C9 copolymer petroleum resin (Exxon 5690), naphthenic oil (4010 naphthenic oil), silane coupling agent modified talc and dicumyl peroxide at a weight ratio of 40:30:20:8:0.1 at 170-180°C; The preparation method of the silane coupling agent modified talc is as follows: 0.165 kg of vinyl triethoxysilane and 0.35 kg of epoxy silane coupling agent KH560 are added into 100 kg of 95% mass concentration ethanol aqueous solution, stirred and dissolved uniformly, then 10 kg of talc powder is added, heated to 55-60°C for reaction, followed by filtration, washing and drying to obtain silane coupling agent modified talc powder.

[0032] Preparation Example 3-2 A hot melt adhesive particle, which is different from that of

Preparation Example 3-1

[0033] Preparation Example 3-3 A hot melt adhesive particle, which is different from that of

Preparation Example 3-1

[0034]

Example 1

Preparation Example 1-1

Preparation Example 2-1

Preparation Example 3-1

[0035] In this example, the preparation method of the viscose fiber absorbent core is as follows: Rolling hot melt adhesive particles on the surface of the first spunlace viscose fiber layer to form a first adhesive layer with a thickness of 1 μm; then covering the first flexible layer on the surface of the first adhesive layer, and then spraying wood pulp fibers and SAP high molecular water-absorbing resin particles on the surface of the first flexible layer in a proportion to form an absorbent core layer with a thickness of 1.8 mm, and finally covering the second flexible layer on the surface of the absorbent core layer to obtain a preformed core body; Rolling hot melt adhesive particles on the surface of the second spunlace viscose fiber layer to form a second adhesive layer with a thickness of 1 μm; then covering the second adhesive layer on the surface of the second flexible layer of the preformed core body and pressing to obtain a viscose fiber absorbent core body.

[0036]

Example 2

Example 1

Preparation Example 1-2

Preparation Example 2-2

[0037]

Example 3

Example 2

Preparation Example 3-2

[0038]

Example 4

Example 2

Preparation Example 3-3

[0039]

Example 5

Example 1

[0040] Comparative Example

Comparative Example 1

Example 1

[0041] Performance Test 1. Referring to QB / T 5650-2021 "Composite Absorbent Core for Disposable Paper Hygienic Products", the absorption speed and back penetration of the core body are tested, the test solution is physiological saline and animal blood, the amount of test solution is 200 mL, and the results are recorded in Table 1 below.

[0042] 2. Air permeability: the air permeability of the samples prepared in the examples and comparative examples of the application is tested according to GB / T 5453-1997, and the test results are recorded in Table 2 below.

[0043] 3. Structural stability: 200 ml and 500 ml of normal saline (mass concentration 0.9%) were taken respectively and heated to 40°C, then the normal saline was added to the core body, the absorbent core sample was placed in a 40±1°C, 65±1% RH test box for 10 min, then the absorbent core sample was taken out for testing; the tester held the two ends of the absorbent core sample with both hands, first swung one end of the absorbent core sample with one hand, repeated 10 times, then reciprocally stretched the two ends of the absorbent core sample with both hands, repeated 10 times, then rubbed the core body with both hands, repeated 10 times, finally observed whether the absorbent core appeared the phenomenon of lumping, and the phenomenon result was recorded in Table 3.

[0044] Table 1 Table 2 Table 3 According to the detection data in Tables 1-3 combined with Example 1 and Comparative Example 1, after the first flexible layer or the second flexible layer of the absorbent core was omitted, the absorption speed of the absorbent core decreased, and at the same time, the structural stability of the absorbent core also decreased, because the flexible layer was missing, which limited and fixed the wood pulp fibers and the high molecular water-absorbing resin, so that the structural stability of the absorbent core decreased.

[0045] According to the detection data in Tables 1-3 combined with Example 1 and Examples 2-4, when the first / second spunlace viscose fiber layer, the first / second flexible layer were both prepared by using the amino silane coupling agent modified viscose fiber, and the first / second adhesive layer was modified by adding the alkenyl silane coupling agent and the epoxy silane coupling agent to obtain the silane coupling agent talc powder, the thickness of the first / second adhesive layer could be as low as 1 μm, which ensured the structural stability of the absorbent core while making the absorbent core have better air permeability.

[0046] According to the detection data in Tables 1-3 combined with Example 1 and Example 5, when the thickness of the first / second adhesive layer increased, the structural stability of the absorbent core could be improved, and the phenomenon of lumping was not easy to occur, but the absorption speed and the air permeability of the absorbent core decreased.

[0047] This specific embodiment is only an explanation of the present application, and is not a limitation of the present application. Those skilled in the art can make modifications to the specific embodiment without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A viscose fiber absorbent core, characterized in that: It includes a first spunlace viscose fiber layer, a first adhesive layer, a first flexible layer, an absorbent core layer, a second flexible layer, a second adhesive layer, and a second spunlace viscose fiber layer arranged sequentially. The first and second spunlace viscose fiber layers are made of viscose fibers through a hydroentangling process. Both the first flexible layer and the second flexible layer are non-hydroentangled viscose fiber layers, and the non-hydroentangled viscose fiber layers are obtained by opening and carding viscose fibers into a viscose fiber web.

2. The viscose fiber absorbent core according to claim 1, characterized in that: The viscose fiber is made of viscose fiber modified with aminosilane coupling agent. The first adhesive layer and the second adhesive layer are made of styrene block copolymer, tackifier, plasticizer, silane coupling agent modified talc and peroxidation initiator in a weight ratio of (35-45):(25-35):(15-25):(7.4-8.3):(0.1-0.2). The silane coupling agent modified talc powder is obtained by modifying talc powder with both alkenyl silane coupling agent and epoxy silane coupling agent.

3. The viscose fiber absorbent core according to claim 2, characterized in that: The aminosilane coupling agent modified viscose fiber is prepared by mixing aminosilane coupling agent and viscose fiber in a weight ratio of (0.1-0.2):

5. In the silane coupling agent modified talc powder, the weight ratio of alkenylsilane coupling agent, epoxysilane coupling agent and talc powder is (0.15-0.2):(0.3-0.4):

10.

4. A viscose fiber absorbent core according to claim 2 or 3, characterized in that: The alkenylsilane coupling agent is at least one of vinyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, and vinyltriethoxysilane.

5. A viscose fiber absorbent core according to claim 2 or 3, characterized in that: The thickness of the first adhesive layer and the second adhesive layer is 1-2 μm.

6. The viscose fiber absorbent core according to claim 1, characterized in that: The absorbent core layer comprises wood pulp fibers and superabsorbent polymer particles.

7. A viscose fiber absorbent core according to claim 1 or 2, characterized in that: The first and second spunlace viscose fiber layers are obtained by sequentially opening and combing the viscose fibers into a viscose fiber web, laying the viscose fiber web at 90° cross-laying, stretching, hydroentangling, and drying. In the hydroentangling step, hydroentangling pressures of 20-30 bar, 40-50 bar, and 80-100 bar are used sequentially.

8. The viscose fiber absorbent core according to claim 7, characterized in that: The areal density of the viscose fiber web is 35-45 g / m². 2 When the viscose fiber web is laid in a 90° cross pattern, the number of viscose fiber web sheets is 6-8.

9. A viscose fiber absorbent core according to claim 7, characterized in that: During the stretching step, the stretching ratio is 2-2.5 times.

10. A method for preparing a viscose fiber absorbent core as described in any one of claims 1-9, characterized in that: Includes the following steps: A first adhesive layer is rolled onto the surface of a first spunlace viscose fiber layer, then a first flexible layer is covered over the surface of the first adhesive layer, an absorbent core layer is formed on the surface of the first flexible layer, and a second flexible layer is covered over the surface of the absorbent core layer to obtain a pre-made core. A second adhesive layer is rolled onto the surface of the second spunlace viscose fiber layer, and then the second adhesive layer is applied to the surface of the second flexible layer of the preformed core and pressed together to obtain the viscose fiber absorbent core.

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