阅读说明：本技术 一种多层复合导流层材料的制备方法 (Preparation method of multilayer composite diversion layer material ) 是由 唐杰 于 2020-04-29 设计创作，主要内容包括：本发明涉及一种多层复合导流层材料的制备方法,属于卫生用品技术领域。本发明以聚丙烯酸钠为原料,采用静电纺丝法制备出纳米纤维膜,以超临界二氧化碳为发泡剂,通过连续挤出聚乳酸泡沫,将纳米纤维膜和聚乳酸泡沫复合,制备一种多层复合导流层材料；亲水性聚乳酸泡沫材料对体液具有一定的渗透速度,可有效防止液体的渗漏,同时,对体液具有物理吸附作用和储液作用；制备的聚丙烯酸钠纳米纤维膜有利于液体竖直方向的渗透,聚乳酸泡沫材料有利于液体纵向扩散,因此制备的多层复合导流层材料具有良好的导流性能,且能贮存液体,瞬吸效果较好。(The invention relates to a preparation method of a multilayer composite diversion layer material, belonging to the technical field of hygienic products. The invention takes sodium polyacrylate as raw material, adopts an electrostatic spinning method to prepare a nanofiber membrane, takes supercritical carbon dioxide as a foaming agent, and compounds the nanofiber membrane and polylactic acid foam by continuously extruding polylactic acid foam to prepare a multilayer composite diversion layer material; the hydrophilic polylactic acid foam material has a certain permeation speed to body fluid, can effectively prevent the leakage of the body fluid, and has a physical adsorption effect and a liquid storage effect on the body fluid; the prepared sodium polyacrylate nanofiber membrane is beneficial to the permeation of liquid in the vertical direction, and the polylactic acid foam material is beneficial to the longitudinal diffusion of the liquid, so that the prepared multilayer composite diversion layer material has good diversion performance, can store the liquid and has a good instant absorption effect.)

1. A preparation method of a multilayer composite diversion layer material is characterized by comprising the following specific preparation steps:

(1) mixing sodium polyacrylate and N, N-dimethylformamide, stirring at room temperature to obtain a spinning solution, performing electrostatic spinning treatment on the spinning solution to obtain a semi-finished product, drying the semi-finished product in an oven at the temperature of 50-60 ℃ to constant weight, and cooling to room temperature to obtain matrix fiber;

(2) opening the matrix fibers to obtain an opened base fabric, and carding the opened base fabric to obtain a carded base fabric; carrying out thermal bonding reinforcement on the carded base cloth, and then carrying out cold air cooling treatment to obtain a fiber film;

(3) drying the polylactic acid particles to obtain dry polylactic acid, preheating the polylactic acid by using a single-screw extruder, and extruding the dry polylactic acid in the preheated single-screw extruder to obtain a foam material;

(4) and covering the fiber film on the foam material, performing compression roller treatment, and cooling to room temperature to obtain the multilayer composite diversion layer material.

2. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the room-temperature stirring treatment step in the step (1) is as follows: mixing sodium polyacrylate and N, N-dimethylformamide according to the mass ratio of 2: 25, and stirring at room temperature for 4-6 h at the stirring speed of 200-300 r/min.

3. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the electrostatic spinning treatment step in the step (1) is as follows: and (3) carrying out electrostatic spinning treatment on the spinning solution under the spinning voltage of 18-22 kV.

4. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the opening treatment step in the step (2) is as follows: and (3) opening the matrix fibers, wherein the linear speed of an opening roller is 600-700 m/min.

5. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the carding step in the step (2) is as follows: carding the opening base fabric, wherein the cylinder speed is 600-800 m/min, the working roller speed is 40-60 m/min, the stripping roller speed is 110-120 m/min, and the doffer speed is 10-20 m/min.

6. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the cold air cooling treatment step in the step (2) is as follows: and thermally bonding and reinforcing the carded base cloth, and cooling the carded base cloth by cold air at the temperature of 30-40 ℃.

7. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the drying treatment step in the step (3) is as follows: and (3) drying the polylactic acid particles in an oven at the temperature of 70-80 ℃ to constant weight.

8. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the preheating treatment step in the step (3) is as follows: preheating a single screw extruder at the temperature of 180 ℃ for 5-10 min.

9. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the extrusion step in the step (3) is as follows: and (2) extruding the dried polylactic acid in a preheated single-screw extruder, introducing supercritical carbon dioxide, wherein the screw rotation speed is 30-50 r/min, the die head temperature is 180-185 ℃, and the extrusion temperature is 190-200 ℃.

10. The method for preparing a multilayer composite flow guide layer material according to claim 1, wherein the method comprises the following steps: the compression roller processing step in the step (4) is as follows: covering the fiber film on the foam material, and pressing the foam material for 1-2 min at the temperature of 140-160 ℃.

Technical Field

The invention relates to a preparation method of a multilayer composite diversion layer material, belonging to the technical field of hygienic products.

Background

The paper diaper is a sanitary nursing product designed for infants, middle-aged and elderly people, urinary incontinence and paralytic patients, and as the sanitary nursing product needs to be in contact with the skin of a user, certain dryness and liquid absorption capacity are required. The diversion layer is used as the middle layer of the surface layer and the absorption core body and can guide urine permeating from the surface layer to be longitudinally conducted and diffused along the paper diaper, so that the urine is uniformly absorbed by the absorption core body. Although there have been many patents and products on the structure of the fluid-guiding layer in recent years, there are some problems as the fluid-guiding layer satisfying the above requirements.

The paper diaper is a multi-structure composite body, and comprises a surface layer, a diversion layer, an absorption core body and a bottom film from top to bottom in sequence. The diversion layer is positioned between the surface layer and the absorption core body and has the functions of enabling the paper diaper to quickly, effectively and uniformly absorb liquid, avoiding the blocking phenomenon caused by overlarge local liquid absorption amount of Super Absorbent Polymer (SAP) and reducing the back seepage amount of the paper diaper. In recent years, there are many reports on the structure of the diversion layer. For example, in the Gong political study, a three-dimensional non-woven fabric diversion layer material is researched, a single-layer fiber net is used as a base layer, a plurality of longitudinal protrusions are formed on the base layer, diversion grooves are formed between every two longitudinal protrusions, and the structure can effectively guide surface layer liquid to permeate downwards, but cannot effectively guide liquid to diffuse along the longitudinal direction. Weasan et al have studied a fluffy flow guide layer, which includes a longitudinal carded web layer that allows liquid to diffuse longitudinally into a transverse carded fluffy web layer, and a transverse carded fluffy web layer that can resist a portion of pressure, allowing the liquid to be stored in the flow guide layer for a short time without reverse osmosis to the water permeable surface layer, but this structure cannot effectively guide the liquid to permeate downwardly into the absorbent core layer.

The existing data on the functional flow guiding layer are reported as follows:

patent CN201320526308.0 discloses a fluffy water conservancy diversion layer for panty-shape diapers is equipped with the water conservancy diversion layer between absorption core and the top layer that permeates water, the water conservancy diversion layer is including vertically combing fibrous layer and transversely combing fluffy fibrous layer, vertically comb fibrous layer with the top layer that permeates water contacts the setting, transversely comb fluffy fibrous layer with the absorption core contacts the setting. The longitudinal carded fiber layer and the transverse fluffy fiber layer described in the patent belong to an ideal state, and in the actual production, the complete longitudinal carded fiber layer (100% of fibers are arranged along the longitudinal direction, which can cause no strength in the transverse direction of the fiber web) is difficult to obtain, the transverse fiber layer (100% of fibers are arranged along the transverse direction, which can cause no strength in the longitudinal direction of the fiber web) is also difficult to obtain, on the other hand, the complete longitudinal carded fiber layer is close to the surface layer, and the diversion needs a certain time, and the instant absorption effect is difficult to achieve particularly when the liquid amount is large, so the method cannot be put into the real production.

The patent CN201410528786.4 discloses a non-woven double-layer composite flow guide layer suitable for paper diapers and a production method thereof, wherein ES, PP and viscose are used as raw materials, PP and viscose are respectively and uniformly mixed with ES fibers with different contents to form a net, then the PP layer and the viscose are compounded through pre-needling, and then the double-layer composite flow guide layer is manufactured through a hot air process. In the preparation process, the needle punching compounding is firstly adopted, and then the hot air penetration reinforcement is adopted, and because two processes are adopted, the rolling and unreeling are required to be added once more, the process is complex, the production cost is high, and the aim of batch production is difficult to achieve.

Patent CN201420462705.0 discloses a novel panty-shape diapers, surface course including the superiors, be located the water conservancy diversion layer of surface course below, be located the layer that absorbs water of water conservancy diversion layer below, and be located the waterproof basement membrane layer of layer below that absorbs water, the water conservancy diversion layer still is equipped with one deck water conservancy diversion layer between the layer with absorbing water, the length of surface course is greater than the water conservancy diversion layer, the length on water conservancy diversion layer is greater than inferior water conservancy diversion layer, the surface course, the cross-section on water conservancy diversion layer and inferior water conservancy diversion layer constitutes a funnel shape, the surface course, the water conservancy diversion layer, inferior water conservancy diversion layer, it realizes connecting layer upon layer through glue to absorb water layer and waterproof basement membrane. Although the patent has the characteristics of instant absorption and multiple absorption, the longitudinal flow guiding along the product cannot be well realized, and the liquid flowing from the funnel-shaped flow guiding layer is locally gathered in the absorption layer, so that the absorption capacity of the high polymer water-absorbent resin (SAP) in other areas in the absorption layer is prevented from being exerted.

27792A discloses a three-dimensional nonwoven fabric flow guide layer material, which adopts a single-layer base layer, a plurality of longitudinal bulges are formed on the base layer, and flow guide grooves are formed between every two longitudinal bulges. This configuration effectively guides the liquid penetration of the facing layer, but does not effectively guide the longitudinal diffusion of the liquid.

Patent CN203436464U discloses a fluffy water conservancy diversion layer, and this water conservancy diversion includes vertical carding fibre web layer and horizontal carding fluffy fibre web layer, and vertical carding layer can vertically diffuse liquid to horizontal fluffy fibre layer, makes liquid descend to ooze fast to the absorption core, and horizontal fibre layer can resist partly pressure, makes liquid short time storage in the water conservancy diversion layer, makes liquid can not reverse the surface course that permeates water, and this kind of structure gas permeability is not good.

In summary, the existing patents relating to the material of the diversion layer of the sanitary product have the problems of poor longitudinal diversion capability, complex processing technology, difficult formation of batch production and difficult realization in actual production. In order to overcome the technical problems of poor flow conductivity, incapability of storing liquid, poor instant absorption effect, complex process, poor permeability and difficulty in mass production of the existing flow-guiding layer material, the development of the flow-guiding layer with good comprehensive performance is very critical and necessary, and the flow-guiding layer plays roles in flow conductivity, liquid storage and barrier, and simultaneously is required to have good air permeability and moisture permeability.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: aiming at the problems of poor flow conductivity, incapability of storing liquid and poor instant absorption effect of the existing flow guide layer material, the preparation method of the multilayer composite flow guide layer material is provided.

In order to solve the technical problems, the invention adopts the following technical scheme:

(1) mixing sodium polyacrylate and N, N-dimethylformamide, stirring at room temperature to obtain a spinning solution, performing electrostatic spinning treatment on the spinning solution to obtain a semi-finished product, drying the semi-finished product in an oven at the temperature of 50-60 ℃ to constant weight, and cooling to room temperature to obtain matrix fiber;

(2) opening the matrix fibers to obtain an opened base fabric, and carding the opened base fabric to obtain a carded base fabric; carrying out thermal bonding reinforcement on the carded base cloth, and then carrying out cold air cooling treatment to obtain a fiber film;

(3) drying the polylactic acid particles to obtain dry polylactic acid, preheating the polylactic acid by using a single-screw extruder, and extruding the dry polylactic acid in the preheated single-screw extruder to obtain a foam material;

(4) and covering the fiber film on the foam material, performing compression roller treatment, and cooling to room temperature to obtain the multilayer composite diversion layer material.

The room-temperature stirring treatment step in the step (1) is as follows: mixing sodium polyacrylate and N, N-dimethylformamide according to the mass ratio of 2: 25, and stirring at room temperature for 4-6 h at the stirring speed of 200-300 r/min.

The electrostatic spinning treatment step in the step (1) is as follows: and (3) carrying out electrostatic spinning treatment on the spinning solution under the spinning voltage of 18-22 kV.

The opening treatment step in the step (2) is as follows: and (3) opening the matrix fibers, wherein the linear speed of an opening roller is 600-700 m/min.

The carding step in the step (2) is as follows: carding the opening base fabric, wherein the cylinder speed is 600-800 m/min, the working roller speed is 40-60 m/min, the stripping roller speed is 110-120 m/min, and the doffer speed is 10-20 m/min.

The cold air cooling treatment step in the step (2) is as follows: and thermally bonding and reinforcing the carded base cloth, and cooling the carded base cloth by cold air at the temperature of 30-40 ℃.

The drying treatment step in the step (3) is as follows: and (3) drying the polylactic acid particles in an oven at the temperature of 70-80 ℃ to constant weight.

The preheating treatment step in the step (3) is as follows: preheating a single screw extruder at the temperature of 180 ℃ for 5-10 min.

The extrusion step in the step (3) is as follows: and (2) extruding the dried polylactic acid in a preheated single-screw extruder, introducing supercritical carbon dioxide, wherein the screw rotation speed is 30-50 r/min, the die head temperature is 180-185 ℃, and the extrusion temperature is 190-200 ℃.

The compression roller processing step in the step (4) is as follows: covering the fiber film on the foam material, and pressing the foam material for 1-2 min at the temperature of 140-160 ℃.

Compared with other methods, the method has the beneficial technical effects that:

(1) the invention takes sodium polyacrylate as raw material, adopts an electrostatic spinning method to prepare a nanofiber membrane, takes supercritical carbon dioxide as a foaming agent, and compounds the nanofiber membrane and polylactic acid foam by continuously extruding polylactic acid foam to prepare a multilayer composite diversion layer material; the hydrophilic polylactic acid foam material has a certain permeation speed to body fluid, can effectively prevent the leakage of the body fluid, and has a physical adsorption effect and a liquid storage effect on the body fluid; the prepared sodium polyacrylate nanofiber membrane is beneficial to the permeation of liquid in the vertical direction, and the polylactic acid foam material is beneficial to the longitudinal diffusion of the liquid, so that the prepared multilayer composite diversion layer material has good diversion performance, can store the liquid and has good instant absorption effect;

(2) the sodium polyacrylate is a water-soluble high-molecular compound, has extremely strong thickening and water-retaining functions, and has high product purity, extremely stable performance, no odor and no odor, and is not decayed after being stored for a long time; the nanofiber membrane is prepared by adopting an electrostatic spinning method, under the action of a high electric field, charged charges on the surfaces of jet flows repel each other, the jet flows are split into a plurality of jet flows, along with the volatilization of a solvent, the jet flows are solidified to form the nanofibers and are collected on a receiver, and the prepared nanofiber membrane has excellent water absorption, good biocompatibility and good chemical activity;

(3) according to the invention, supercritical carbon dioxide is used as a foaming agent, and polylactic acid foam is continuously extruded, so that the polylactic acid is a novel environment-friendly plastic with good performance, belongs to a renewable material, has degradability, can be naturally degraded in a natural environment, is water and carbon dioxide as final decomposed products, cannot pollute the environment, and has good biocompatibility; the prepared polylactic acid foam has a plurality of excellent performances such as light weight, high impact strength, high specific strength, good heat insulation performance, good sound insulation performance, strong moisture absorption performance and the like, and the polylactic acid foam plastic is renewable, easy to degrade and free of environmental pollution after degradation, and in addition, the polylactic acid foam plastic has the advantages of good mechanical performance, strong heat resistance and the like;

(4) the invention compounds the nanometer fiber film and the polylactic acid foam to prepare the multilayer composite diversion layer material, the nanometer fiber film is a substance with porous, the specific surface area is large, the liquid can rapidly penetrate into the pores of the fiber to complete the moisture absorption process of the fiber, the pores of the polylactic acid foam are larger than the pores of the nanometer fiber film, and the two are combined, so the prepared multilayer composite diversion layer material has good instant absorption effect and diversion performance.

Detailed Description

Mixing sodium polyacrylate and N, N-dimethylformamide according to the mass ratio of 2: 25, stirring at room temperature for 4-6 h at the stirring speed of 200-300 r/min to obtain a spinning solution, performing electrostatic spinning treatment on the spinning solution at the spinning voltage of 18-22 kV to obtain a semi-finished product, drying the semi-finished product in an oven at the temperature of 50-60 ℃ to constant weight, and cooling to room temperature to obtain matrix fibers; opening the matrix fibers, wherein the linear speed of an opening roller is 600-700 m/min to obtain an opening base fabric, carding the opening base fabric, wherein the cylinder speed is 600-800 m/min, the working roller speed is 40-60 m/min, the stripping roller speed is 110-120 m/min, and the doffer speed is 10-20 m/min to obtain a carding base fabric; thermally bonding and reinforcing the carded base cloth, and cooling the carded base cloth by cold air at the temperature of 30-40 ℃ to obtain a fiber film; placing the polylactic acid particles in an oven at the temperature of 70-80 ℃ for drying to constant weight to obtain dried polylactic acid, preheating a single-screw extruder at the temperature of 180 ℃ for 5-10 min, placing the dried polylactic acid in the preheated single-screw extruder for extrusion, introducing supercritical carbon dioxide, controlling the screw rotation speed at 30-50 r/min, the die head temperature at 180-185 ℃, and the extrusion temperature at 190-200 ℃ to obtain a foam material; covering a fiber film on the foam material, pressing the foam material for 1-2 min at the temperature of 140-160 ℃, and cooling the foam material to room temperature to obtain the multilayer composite diversion layer material.