CN107242938B

CN107242938B - Water-absorbing core body and preparation method and application thereof

Info

Publication number: CN107242938B
Application number: CN201710553198.XA
Authority: CN
Inventors: 陈建辉
Original assignee: Individual
Current assignee: Hangzhou Credible Sanitary Products Co ltd
Priority date: 2017-07-07
Filing date: 2017-07-07
Publication date: 2021-02-09
Anticipated expiration: 2037-07-07
Also published as: CN107242938A

Abstract

The invention relates to a water-absorbing core body and a preparation method and application thereof. The preparation method of the water absorption core body comprises the following steps: loosening and carding the chemical fibers to form a fluffy cotton layer; forming a first flow guide layer on the fluffy cotton layer; paving high-molecular water-absorbent resin powder on the first diversion layer to obtain a water-absorbent layer; and forming a second flow guide layer on the water absorption layer to obtain the laminated body, wherein the material of the first flow guide layer and the material of the second flow guide layer both comprise the following components in percentage by mass: 70-90% of fluff pulp and 10-30% of hot-melt fiber; carrying out hot air penetration and shaping on the laminated piece to obtain a shaped laminated piece; and rolling and cooling the shaped laminated body, cutting by using ultrasonic waves, and fusing the hot melt fibers in the first flow guide layer and the second flow guide layer at the cut part to obtain the water absorbing core body. The water-absorbent core prepared by the method has a good absorption effect, and the water-absorbent resin is not easy to delaminate after being expanded.

Description

Water-absorbing core body and preparation method and application thereof

Technical Field

The invention relates to the field of hygienic products, in particular to a water-absorbing core body and a preparation method and application thereof.

Background

In general, since a diaper, a sanitary napkin, or the like is required to have a good water absorbing property, it generally has a water absorbent core. At present, the production methods of the water-absorbing core body mainly include two methods, one method is that fluff pulp and high POLYMER water-absorbing resin (SAP) are mixed on line, although the cost is low, the product diffusion is fast, the multiple absorption effect is good, but after the water-absorbing resin swells after absorbing water, the connection between the fluff pulp is poor, the fluff pulp is easy to break and cause a lump, the use comfort degree is influenced, the effective use time is also influenced, and in order to avoid the lump, manufacturers reduce the using amount of the water-absorbing resin, but the absorption amount and the use time of the product are reduced. The other mode is that a fluffy non-woven fabric is adopted to fix SAP, thermosol composite bulked paper (or dust-free paper, non-woven fabric and the like) is respectively adopted on the upper surface and the lower surface, and a product is obtained after rolling and slitting.

Disclosure of Invention

Therefore, it is necessary to provide a method for producing a water absorbent core which is less likely to delaminate after swelling and has a good absorption effect.

In addition, a water-absorbing core body and application thereof are also provided.

A preparation method of a water-absorbing core body comprises the following steps:

loosening and carding the chemical fibers to form a fluffy cotton layer;

forming a first flow guide layer on the fluffy cotton layer, wherein the first flow guide layer comprises the following materials in percentage by mass: 70-90% of fluff pulp and 10-30% of hot-melt fiber;

paving high-molecular water-absorbent resin powder on the first diversion layer to obtain a water-absorbent layer;

forming a second flow guide layer on the water absorption layer to obtain a laminated body, wherein the second flow guide layer comprises the following materials in percentage by mass: 70-90% of fluff pulp and 10-30% of hot-melt fiber;

carrying out hot air penetration and shaping on the laminated piece to obtain the shaped laminated piece; and

and rolling and cooling the shaped laminated body, cutting by using ultrasonic waves, and fusing the hot melt fibers in the first flow guide layer and the second flow guide layer at the cut part to obtain the water-absorbing core body.

The preparation method of the water absorbent core body comprises the steps of forming a first flow guide layer on a fluffy cotton layer, paving high-molecular water absorbent resin powder on the first flow guide layer to form a water absorbent layer, forming a second flow guide layer on the water absorbent layer, wherein the first flow guide layer and the second flow guide layer are made of 70-90% fluff pulp and 10-30% hot melt fibers according to mass percentage, namely the water absorbent layer is positioned between the first flow guide layer and the second flow guide layer containing the hot melt fibers, and when hot air is penetrated and shaped, the hot melt fibers in the first flow guide layer and the second flow guide layer are melted to connect the fluffy cotton layer, the first flow guide layer, the water absorbent layer and the second flow guide layer together, so that the layers of the water absorbent core body are well connected to reduce the layering problem caused by water absorbent resin powder after water absorption expansion; the shaped laminated member is rolled and cooled, and then is cut by ultrasonic waves, so that cutting is realized, hot melt fibers in the first flow guide layer and hot melt fibers in the second flow guide layer at the cut part can be fused again under the action of the ultrasonic waves, the connectivity between the first flow guide layer and the second flow guide layer is further increased, and the edge sealing effect is also realized; meanwhile, as the first flow guide layer and the second flow guide layer both contain fluff pulp, the fluff pulp can play a role in flow guide, so that the first flow guide layer and the second flow guide layer both have better diffusibility to improve the diffusion and absorption of the water absorption core body, thereby effectively preventing the problems of side leakage, back leakage and the like; and because the chemical fiber of the fluffy cotton layer is only pulled loose and carded and is not subjected to glue spraying treatment, the softness is better, and the fluffy cotton layer is fluffier, so that a space is better provided for the expansion of the high-molecular water-absorbent resin powder, and the expansion space of the high-molecular water-absorbent resin is ensured.

In one embodiment, the chemical fiber comprises polyester fiber, polypropylene fiber and polyethylene fiber, and the polyester fiber accounts for 3-70% of the chemical fiber by mass.

In one embodiment, the length of the fibers of the fluffy cotton layer is 38 mm-64 mm, and the specification of the fluffy cotton layer is 1.5D-35D.

In one embodiment, the fluff pulp is wood pulp.

In one embodiment, the hot melt fibers comprise polypropylene fibers and polyethylene fibers.

In one embodiment, the step of through-air-setting the laminate is performed at a temperature of 120 ℃ to 150 ℃.

In one embodiment, the step of rolling and cooling the shaped laminate is specifically: and (3) rolling the shaped laminated piece, and simultaneously performing air draft cooling, wherein the relative humidity of the laminated piece is 3-10% RH.

In one embodiment, before the step of subjecting the laminate to through-air fixing, a step of forming a plurality of the water-absorbent resin layers and a plurality of the second flow guide layers alternately on the second flow guide layer is further included.

The water-absorbing core body is prepared by the preparation method of the water-absorbing core body.

The water-absorbing core body is applied to the core of a paper diaper or the core of a sanitary towel.

Drawings

Fig. 1 is a flowchart of a method for producing a water absorbent core according to an embodiment.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1, a method for manufacturing a water absorbent core according to an embodiment includes the steps of:

step S110: and (3) loosening and carding the chemical fibers to form a fluffy cotton layer.

That is, the chemical fiber of fluffy cotton layer has only been through drawing loose and combing, and has not been through spouting gluey processing to make fluffy cotton layer have better compliance, fluffy more, thereby provide the space for the inflation of polymer absorbent resin powder better, guaranteed polymer absorbent resin's inflation space.

Wherein the length of the fiber of the fluffy cotton layer is 38 mm-64 mm, and the specification is 1.5D-35D (wherein, the 1.5D-35D represents that the weight of 9000 meters of the fiber is 1.5 g-35 g).

Wherein the chemical fiber comprises polyester fiber, polypropylene fiber and polyethylene fiber; in the chemical fiber, the mass percentage of the polyester fiber is 3-70%.

Further, in the chemical fiber, the total mass percentage content of the polypropylene fiber and the polyethylene fiber is 30-97%.

Furthermore, in the chemical fiber, the mass percentage of the polypropylene fiber and the polyethylene fiber is 2-5: 5-8.

Step S120: and forming a first flow guide layer on the fluffy cotton layer.

Wherein, according to the mass percent, first water conservancy diversion layer includes: 70 to 90 percent of fluff pulp and 10 to 30 percent of hot melt fiber.

Wherein, the fluff pulp is straw pulp or wood pulp, and is preferably wood pulp. Because the fiber in the straw pulp is shorter, the flow guide effect is poorer, and compared with the straw pulp, the fiber in the wood pulp is longer, and the flow guide effect is better.

Wherein the hot melt fiber comprises polypropylene fiber and polyethylene fiber. Specifically, in the hot-melt fibers, the mass percentage of the polypropylene fibers to the polyethylene fibers is 2-5: 5-8.

Wherein, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 2D-3D.

Specifically, before step S120, the method further includes the step of crushing the fluff pulp, sieving the crushed fluff pulp with a sieve having a diameter of 2.5 mm to 8mm, and mixing the fluff pulp with the hot-melt fibers to obtain a mixed material. At this time, step S120 is to lay the mixture on the fluffy cotton layer to form a first flow guiding layer. The paper obtained by sieving the fluff pulp with a sieve with the diameter of 2.5 mm-8 mm is relatively qualified.

Step S130: and paving high-molecular water-absorbent resin (SAP) powder on the first diversion layer to obtain the water-absorbent layer.

Wherein the particle size of the high molecular water-absorbing resin is 20-300 meshes. Too large or too small particle size affects the thickness of the water-absorbent core and the density of the water-absorbent polymer resin in the water-absorbent core.

Step S140: and forming a second flow guide layer on the water absorption layer to obtain the laminated body.

Wherein, according to the mass percent, the second water conservancy diversion layer includes: 70 to 90 percent of fluff pulp and 10 to 30 percent of hot melt fiber.

The treatment method and content of the fluff pulp and the hot melt fibers of the second flow guide layer in step S140 are the same as those of the fluff pulp and the hot melt fibers of the first flow guide layer in step S120.

Specifically, step S140 is: and paving the mixed material on the water absorption layer to form a second flow guide layer.

Step S150: and (4) carrying out hot air penetration and shaping on the laminated piece to obtain the shaped laminated piece.

And connecting the fluffy cotton layer, the first flow guide layer, the water absorption layer and the second flow guide layer together by carrying out hot air through setting on the laminated body so as to melt the hot melt fibers of the first flow guide layer and the second flow guide layer.

Specifically, in the step of hot air penetration shaping of the laminated piece, the temperature is 120-150 ℃.

Further, before the step of performing through-air fixing, the method further comprises a step of forming a plurality of water-absorbent resin layers and a plurality of second flow guide layers alternately arranged on the second flow guide layer.

Step S160: and rolling and cooling the shaped laminated body, cutting by using ultrasonic waves, and fusing the hot melt fibers in the first flow guide layer and the second flow guide layer at the cut part to obtain the water absorbing core body.

Specifically, the steps of rolling and cooling the shaped laminate are specifically: and (3) performing air draft cooling on the shaped laminated piece while rolling, and enabling the relative humidity of the laminated piece to be 3-10% RH, so that the thickness and the humidity of the shaped laminated piece are adjusted. Because the laminated piece is heated in the hot air penetration and shaping process, the laminated piece has residual heat after hot air penetration and shaping, and the laminated piece does not need to be heated in the rolling process.

Wherein the pressure during rolling is 0.3MPa to 0.8 MPa.

Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 80 m/min-250 m/min, and the ultrasonic frequency is above 20000 Hz. The cutting speed is matched with the ultrasonic frequency, so that the cutting quality and the better edge sealing effect can be ensured.

Specifically, the water absorption core body comprises the following components in percentage by mass: 4 to 10 percent of chemical fiber (namely the chemical fiber forming the fluffy cotton layer), 16 to 20 percent of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 62 to 70 percent of high molecular water-absorbent resin powder and 6 to 12 percent of hot melt fiber (the total content of the hot melt fiber of the first flow guide layer and the second flow guide layer).

Through adopting ultrasonic cutting to make the hot melt fibre in the first water conservancy diversion layer of cutting department and the hot melt fibre in the second water conservancy diversion layer fuse mutually in the cutting, further increase the connection between first water conservancy diversion layer and the second water conservancy diversion layer, make first water conservancy diversion layer and second water conservancy diversion layer have better connectivity, play the effect of banding simultaneously.

The preparation method of the water absorbent core body comprises the steps of forming a first flow guide layer on a fluffy cotton layer, paving high-molecular water absorbent resin powder on the first flow guide layer to form a water absorbent layer, forming a second flow guide layer on the water absorbent layer, wherein the first flow guide layer and the second flow guide layer are made of 70-90% fluff pulp and 10-30% hot melt fibers according to mass percentage, namely the water absorbent layer is positioned between the first flow guide layer and the second flow guide layer containing the hot melt fibers, and the hot melt fibers in the first flow guide layer and the second flow guide layer are melted to connect the fluffy cotton layer, the first flow guide layer, the water absorbent layer and the second flow guide layer together when hot air is penetrated and shaped, so that the layers of the water absorbent core body are well connected to reduce the layering problem caused by water absorbent resin powder after water absorption expansion; the shaped laminated member is rolled and cooled, and then is cut by ultrasonic waves, so that cutting is realized, hot melt fibers in the first flow guide layer and hot melt fibers in the second flow guide layer at the cut part can be fused again under the action of the ultrasonic waves, the connectivity between the first flow guide layer and the second flow guide layer is further increased, and the edge sealing effect is also realized; meanwhile, as the first flow guide layer and the second flow guide layer both contain fluff pulp, the fluff pulp can play a role in flow guide, so that the first flow guide layer and the second flow guide layer both have better diffusibility to improve the diffusion and absorption of the water absorption core body, thereby effectively preventing the problems of side leakage, back leakage and the like; and because the chemical fiber of the fluffy cotton layer is only pulled loose and carded and is not subjected to glue spraying treatment, the softness is better, and the fluffy cotton layer is fluffier, so that a space is better provided for the expansion of the high-molecular water-absorbent resin powder, and the expansion space of the high-molecular water-absorbent resin is ensured.

And the chemical fiber forming the fluffy cotton layer of the water absorption core body also comprises polypropylene fiber and polyethylene fiber, so that the fluffy cotton layer can be well connected with the first flow guide layer when being penetrated by hot air and cut by ultrasonic waves, and the connectivity of the whole water absorption core body is further improved.

The water-absorbing core body can be used as a core sheet of a paper diaper or a core sheet of a sanitary towel. Because the absorbent core has a good absorption effect and the high-molecular water-absorbent resin is not easy to layer after being expanded, the paper diaper or sanitary towel using the absorbent core as a chip has a good absorption effect and is not easy to cause the problems of side leakage and back leakage.

The following are specific examples (the following examples, unless otherwise specified, contain no other components not specifically indicated except for unavoidable impurities):

example 1

The preparation process of the water absorbent core of the embodiment is as follows:

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise 50% by mass of polyester fibers, 50% by mass of the total mass of the polypropylene fibers and the polyethylene fibers, the mass ratio of the polypropylene fibers to the polyethylene fibers is 4:6, the length of the fibers of the fluffy cotton layer is 60-64 mm, and the specification is 20D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 5mm, and then the fluff pulp and the hot-melt fiber are mixed according to the mass percentage of 80 percent to 20 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 4:6, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 3D.

(3) And (3) paving the mixed material in the step (2) on the fluffy cotton layer to form a first flow guide layer.

(4) And paving high-molecular water-absorbing resin powder with the granularity of 150 meshes on the first diversion layer to obtain the water-absorbing layer.

(5) And (3) paving the mixed material in the step (2) on the water absorption layer to obtain a second flow guide layer and obtain a laminated member.

(6) The method comprises the steps of carrying out hot air penetration and shaping treatment on a laminated piece in a hot box at 130 ℃, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 8% RH and the thickness to be 2.5 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.5 Mpa.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 180 m/min, and the ultrasonic frequency is 21000 Hz; the whole water-absorbing core body consists of 9 percent of chemical fiber (namely the chemical fiber forming the fluffy cotton layer), 18 percent of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 65 percent of high polymer water-absorbing resin powder and 8 percent of hot melt fiber (the total content of the hot melt fiber of the first flow guide layer and the second flow guide layer) by mass percentage.

And (3) testing the connectivity: the water-absorbing core of this example was subjected to water-absorbing treatment until the water-absorbing core absorbed water sufficiently (i.e., saturated), and whether the water-absorbing core was layered or not was observed. The results of delamination of the absorbent core of this example are shown in Table 1.

And (3) testing the absorption speed: 0.1g of the suction of this example is weighed out with an electronic balanceThe wick, with an accuracy of 0.001g, was then placed in a 100ml beaker and the beaker was shaken to disperse the wick evenly over the bottom of the beaker. 5ml of standard synthetic test solution with the temperature of 23 ℃ is measured by a measuring cylinder, poured into a beaker filled with a water-absorbing core body, timing is started at the same time, the fluidity of the liquid in the beaker disappears when the beaker is slightly inclined, and the time taken for absorption is recorded. The absorption time is expressed in seconds and two measurements are carried out simultaneously. The arithmetic mean of the two measurements is used and is shown in Table 1. Wherein, the standard synthetic test solution is prepared according to the main physical properties of animal blood (pig blood), has similar flowing and absorbing characteristics, and can well simulate the human body menses performance. The standard synthetic test solution comprises the following specific components: 860ml of distilled water or deionized water, 10.00g of sodium chloride, 40.00g of sodium carbonate, 140ml of glycerol (glycerin), 1.00g of sodium benzoate, a proper amount of food pigment, 5.00g of sodium carboxymethylcellulose and 1% (volume fraction) of standard vehicle. The physical properties of the standard synthetic test solution at (23. + -. 1) ° C were as follows: density of (1.05. + -. 0.05) g/cm³Viscosity (11.9 ± 0.7) s (measured with paint cup No. 4), surface tension: (36. + -. 4) mN/m.

Measurement of absorption amount:

(1) instruments and reagents

a. The electronic balance has a sensitive quantity of 0.001 g.

b. The paper tea bag has size of 60mm 85mm, and air permeability (230 + -50) L/(min 100 cm)²) (pressure difference 124pa)

c. The clip is used for fixing the tea bag.

d. Standard synthetic test solution

(2) The determination step comprises:

a. a 0.2g sample was weighed to the nearest 0.001g and the mass was reported as m 0.202 g. The whole sample is poured into the bottom of the tea bag (F.1.2), and the sample attached to the inner side of the tea bag is also poured into the bottom of the tea bag.

b. The tea bag is sealed and soaked in a beaker filled with a sufficient amount of standard synthetic test solution (F.1.4) for 30 min.

c. The bag containing the sample was gently lifted out, suspended by a clip (F.1.3), and allowed to drip for 10min at rest. When a plurality of tea bags are hung at the same time, the tea bags are not contacted with each other.

d. After 10min, the weight m of the tea bag containing the sample is weighed₁＝8.032g。

e. Using the tea bag without sample to simultaneously perform blank value measurement, weighing the mass of the blank test tea bag, and recording the mass as m₂＝2g。

(3) Presentation of the results of the measurement

The absorption amount of the sample can be calculated by the formula (F.1):

wherein w is the absorption of the sample in grams per gram (g/g);

m₁-the mass in grams (g) of the tea bag containing the sample;

m₂-mass in grams (g) of blank test tea bag;

m-the mass of the sample is weighed in grams (g).

The measurement is carried out twice at the same time, and the arithmetic mean value is taken as the measurement result, and the result is trimmed to one digit after the decimal point.

Example 2

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers into an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise 70% by mass of polyester fibers, 30% by mass of the total mass of the polypropylene fibers and the polyethylene fibers, the mass ratio of the polypropylene fibers to the polyethylene fibers is 2:5, the length of the fibers of the fluffy cotton layer is 38-40 mm, and the specification is 1.5D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 2.5 mm, and then the fluff pulp and the hot-melt fibers are mixed according to the mass percentage of 70 percent to 30 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 2:5, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 2D.

(4) And paving high-molecular water-absorbing resin powder with the granularity of 20 meshes on the first diversion layer to obtain the water-absorbing layer.

(6) Carrying out hot air penetration and shaping treatment on the laminated piece in a hot box at 120 ℃, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 3% RH and the thickness to be 3 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.4 MPa.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 80 m/min, and the ultrasonic frequency is 21500 Hz; the whole water-absorbing core body consists of 10 percent of chemical fiber (namely the chemical fiber forming the fluffy cotton layer), 16 percent of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 68 percent of high-molecular water-absorbent resin powder and 6 percent of hot-melt fiber (the total content of the hot-melt fiber of the first flow guide layer and the second flow guide layer) by mass percentage.

The same test methods as in example 1 were carried out to obtain the water-absorbent core of this example, the connectivity, water absorption capacity and absorption time of which are shown in Table 1.

Example 3

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise 3% by mass of polyester fibers, 97% by mass of the total mass of the polypropylene fibers and the polyethylene fibers, the mass ratio of the polypropylene fibers to the polyethylene fibers is 2:8, the length of each fiber of the fluffy cotton layer is 50-54 mm, and the specification is 35D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 8mm, and then the fluff pulp and the hot-melt fibers are mixed according to the mass percentage of 85 percent to 15 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 2:8, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 3D.

(4) And paving high-molecular water-absorbent resin powder with the granularity of 300 meshes on the first diversion layer to obtain the water-absorbent layer.

(6) Carrying out hot air penetration and shaping treatment on the laminated piece in a hot box at 150 ℃, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 8% RH and the thickness to be 3.5 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.3 MPa.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 250 m/min, and the ultrasonic frequency is 26000 Hz; the whole water-absorbing core body consists of 4% of chemical fibers (namely the chemical fibers forming the fluffy cotton layer), 16% of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 70% of high-molecular water-absorbent resin powder and 10% of hot-melt fibers (the total content of the hot-melt fibers of the first flow guide layer and the second flow guide layer) by mass percentage.

Example 4

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise 20 mass percent of polyester fibers, 80 mass percent of the total mass percent of the polypropylene fibers and the polyethylene fibers, the mass ratio of the polypropylene fibers to the polyethylene fibers is 5:8, the length of each fiber of the fluffy cotton layer is 60-64 mm, and the specification is 30D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 4mm, and then the fluff pulp and the hot melt fiber are mixed according to the mass percentage of 78 percent to 22 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 5:8, the length of the hot melt fiber is 3 mm-5 mm, and the specification is 2D.

(4) And paving high-molecular water-absorbing resin powder with the granularity of 100 meshes on the first diversion layer to obtain the water-absorbing layer.

(6) Carrying out hot air penetration and shaping treatment on the laminated piece at 125 ℃, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 6% RH and the thickness to be 2.5 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.8 MPa.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 100 m/min, and the ultrasonic frequency is 26300 Hz; the whole water-absorbing core body consists of 5% of chemical fibers (namely the chemical fibers forming the fluffy cotton layer), 19% of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 64% of high-molecular water-absorbent resin powder and 12% of hot-melt fibers (the total content of the hot-melt fibers of the first flow guide layer and the second flow guide layer) by mass percentage.

Example 5

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise 30% by mass of polyester fibers, 70% by mass of the total of the polypropylene fibers and the polyethylene fibers, the mass ratio of the polypropylene fibers to the polyethylene fibers is 5:5, the length of each fiber of the fluffy cotton layer is 60-64 mm, and the specification is 30D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 6 mm, and then the fluff pulp and the hot-melt fibers are mixed according to the mass percentage of 82 percent to 18 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot-melt fibers are polypropylene fibers and polyethylene fibers, the mass percentage of the polypropylene fibers to the polyethylene fibers is 5:5, the length of the hot-melt fibers is 4-8 mm, and the specification is 2D.

(4) And paving high-molecular water-absorbing resin powder with the granularity of 80 meshes on the first diversion layer to obtain the water-absorbing layer.

(6) And carrying out hot air penetration and shaping treatment on the laminated piece at 145 ℃, rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 10% RH and the thickness to be 3 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.6 MPa.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 200 m/min, and the ultrasonic frequency is 30000 Hz; the whole water-absorbing core body consists of 8 percent of chemical fiber (namely the chemical fiber forming the fluffy cotton layer), 20 percent of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 64 percent of high polymer water-absorbing resin powder and 8 percent of hot melt fiber (the total content of the hot melt fiber of the first flow guide layer and the second flow guide layer) by mass percentage.

Example 6

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise polyester fibers, polypropylene fibers and polyethylene fibers, the mass percentage of the polyester fibers is 60%, the total mass percentage of the polypropylene fibers and the polyethylene fibers is 40%, the mass ratio of the polypropylene fibers to the polyethylene fibers is 3:7, the length of each fiber of the fluffy cotton layer is 60-64 mm, and the specification is 30D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 3 mm, and then the fluff pulp and the hot-melt fibers are mixed according to the mass percentage of 90% to 10% to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 3:7, the length of the hot melt fiber is 3-8 mm, and the specification is 2D.

(4) And paving high-molecular water-absorbing resin powder with the granularity of 250 meshes on the first diversion layer to obtain the water-absorbing layer.

(6) The method comprises the steps of carrying out hot air penetration and shaping treatment on a laminated piece at 140 ℃, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 6% RH and the thickness to be 3.5 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.7 MPa.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 150 m/min, and the ultrasonic frequency is 22500 Hz; the whole water-absorbing core body consists of 4% of chemical fibers (namely the chemical fibers forming the fluffy cotton layer), 18% of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 70% of high-molecular water-absorbing resin powder and 8% of hot-melt fibers (the total content of the hot-melt fibers of the first flow guide layer and the second flow guide layer) by mass percentage.

Example 7

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 7 mm, and then the fluff pulp and the hot-melt fibers are mixed according to the mass percentage of 85 percent to 15 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 4:6, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 3D.

(4) And paving high-molecular water-absorbent resin powder with the granularity of 120 meshes on the first diversion layer to obtain a first water-absorbent layer.

(5) And (3) paving the mixed material obtained in the step (2) on the first water absorption layer to obtain a second flow guide layer.

(6) And paving high-molecular water-absorbent resin powder with the granularity of 120 meshes on the second diversion layer to obtain a second water-absorbent layer.

(7) And (3) paving the mixed material in the step (2) on the second water absorption layer to obtain a second flow guide layer and obtain a laminated body.

(8) The method comprises the steps of carrying out hot air penetration and shaping treatment on a laminated piece at 140 ℃, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 5% RH and the thickness to be 3 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.4 MPa.

(9) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer, the second flow guide layer and the third flow guide layer at the cut part, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 220 m/min, and the ultrasonic frequency is 21400 Hz; the whole water-absorbing core body consists of 6% of chemical fibers (namely the chemical fibers forming the fluffy cotton layer), 18% of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the two second flow guide layers), 68% of high-molecular water-absorbent resin powder (the total content of the high-molecular water-absorbent resin powder of the two water-absorbing layers) and 8% of hot-melt fibers (the total content of the hot-melt fibers of the first flow guide layer and the two second flow guide layers) by mass percentage.

Example 8

(1) vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers comprise polyester fibers, polypropylene fibers and polyethylene fibers, the mass percentage of the polyester fibers is 60%, the total mass percentage of the polypropylene fibers and the polyethylene fibers is 40%, the mass ratio of the polypropylene fibers to the polyethylene fibers is 4:6, the length of the fibers of the fluffy cotton layer is 60-64 mm, and the specification is 30D.

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 7 mm, and then the fluff pulp and the hot-melt fibers are mixed according to the mass percentage of 75 percent to 25 percent to obtain a mixed material. Wherein the fluff pulp is wood pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 4:6, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 3D.

(4) And paving high-molecular water-absorbing resin powder with the granularity of 150 meshes on the first diversion layer to obtain a first water-absorbing layer.

(6) And paving high-molecular water-absorbing resin powder with the granularity of 150 meshes on the second diversion layer to obtain a second water-absorbing layer.

(8) The method comprises the steps of carrying out hot air penetration shaping treatment on a laminated piece in a 135 ℃ hot box, then rolling the shaped laminated piece with residual heat, simultaneously carrying out air draft cooling, enabling the relative humidity of the laminated piece to be 7% RH and the thickness to be 2.5 mm, and curling the cooled laminated piece, wherein the pressure during rolling is 0.3 MPa.

(9) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer, the second flow guide layer and the third flow guide layer at the cut part, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 160 m/min, and the ultrasonic frequency is 25650 Hz; according to the mass percentage, the whole water-absorbing core body consists of 10% of chemical fibers (namely the chemical fibers forming the fluffy cotton layer), 18% of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the two second flow guide layers), 62% of high polymer water-absorbent resin powder (the total content of the high polymer water-absorbent resin powder of the two water-absorbing layers) and 10% of hot-melt fibers (the total content of the hot-melt fibers of the first flow guide layer and the two second flow guide layers).

Example 9

(2) The fluff pulp is crushed and sieved by a sieve with the diameter of 5mm, and then the fluff pulp and the hot-melt fiber are mixed according to the mass percentage of 80 percent to 20 percent to obtain a mixed material. Wherein the fluff pulp is straw pulp; the hot melt fiber is polypropylene fiber and polyethylene fiber, the mass percentage of the polypropylene fiber to the polyethylene fiber is 4:6, the length of the hot melt fiber is 3 mm-8 mm, and the specification is 3D.

(7) And carrying out ultrasonic cutting on the laminated piece by adopting an ultrasonic splitting machine, fusing the hot melt fibers in the first flow guide layer and the hot melt fibers in the second flow guide layer at the cutting position, and simultaneously cutting and edge sealing to obtain the water-absorbing core body. Wherein, the technological parameters of ultrasonic cutting are as follows: the cutting speed is 180 m/min, and the ultrasonic frequency is 25000 Hz; the whole water-absorbing core body consists of 9 percent of chemical fiber (namely the chemical fiber forming the fluffy cotton layer), 18 percent of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 65 percent of high polymer water-absorbing resin powder and 8 percent of hot melt fiber (the total content of the hot melt fiber of the first flow guide layer and the second flow guide layer) by mass percentage.

Comparative example 1

The procedure for the preparation of the absorbent core of comparative example 1 was as follows:

crushing the fluff pulp, and sieving the fluff pulp by a sieve with the diameter of 5 mm; according to the mass percentage, 22% of fluff pulp and 78% of high molecular water-absorbent resin powder are mixed on a production line of a toilet paper machine to form a water-absorbent core, wherein the particle size of the high molecular water-absorbent resin powder is 150 meshes, and the fluff pulp is wood pulp.

Since the water absorbent core of comparative example 1 had a one-layer structure, no delamination occurred and no connectivity test was required. The water absorption capacity and absorption time of the absorbent core of comparative example 1 were obtained by the same test methods as in example 1 and are shown in Table 1.

Comparative example 2

The procedure for preparing the water-absorbent core of comparative example 2 was as follows: .

Adopting upper and lower 45g of dust-free paper, sequentially adding macromolecular water-absorbent resin powder, 6% of fluffy cotton and 2% of hot melt adhesive in the middle, sealing the upper and lower layers of dust-free paper by using fluffy non-woven fabrics, fixing the macromolecular water-absorbent resin powder in the middle, and rolling and slitting to obtain a product, wherein the water-absorbent core body comprises 24% of dust-free paper, 68% of macromolecular water-absorbent resin powder, 6% of fluffy cotton and 2% of hot melt adhesive in percentage by mass; the hot melt adhesive is EVA resin.

The same test methods as in example 1 were used to obtain the water-absorbent core of comparative example 2 having the connectivity, water absorption capacity and absorption time shown in Table 1.

Comparative example 3

The procedure for preparing the water-absorbent core of comparative example 3 was as follows: .

(1) Vibrating chemical fibers in a bale opener, conveying the chemical fibers to an opener by wind for loosening, conveying the loosened chemical fibers into a last cotton box by wind for storage, conveying the chemical fibers into an automatic cotton box by wind for quantification, and carding the cotton fibers in a carding machine to form a fluffy cotton layer, wherein the chemical fibers are polyester fibers, polypropylene fibers and polyethylene fibers, the mass percentage of the polyester fibers is 50%, the total mass percentage of the polypropylene fibers and the polyethylene fibers is 50%, the length of the fibers of the fluffy cotton layer is 60-64 mm, and the specification is 20D.

(7) Cutting with a steel knife, sealing the upper and lower layers of dust-free paper with non-woven fabric, fixing the middle polymer water-absorbent resin SAP, and rolling and slitting to obtain the water-absorbent core. Wherein, the whole water-absorbing core body consists of 9 percent of chemical fiber (namely the chemical fiber forming the fluffy cotton layer), 18 percent of fluff pulp (the total content of the fluff pulp of the first flow guide layer and the second flow guide layer), 65 percent of high molecular water-absorbing resin powder and 8 percent of hot melt fiber (the total content of the hot melt fiber of the first flow guide layer and the second flow guide layer) by mass percentage.

The same test methods as in example 1 were used to obtain the water-absorbent core of comparative example 3 having the connectivity, water absorption capacity and absorption time shown in Table 1.

Table 1 shows the connectivity, water absorption capacity and absorption time of the water-absorbent core of examples 1 to 9 and comparative examples 1 to 3.

TABLE 1

As can be seen from Table 1, the water-absorbing cores of examples 1 to 9 have no delamination phenomenon after fully absorbing water, while the water-absorbing core of comparative example 1 has a one-layer structure and no delamination phenomenon, and the water-absorbing cores of comparative examples 2 and 3 have delamination phenomenon after fully absorbing water, which obviously shows that the water-absorbing cores of examples 1 to 9 have better connectivity. Wherein the water absorption capacity and the absorption time of the water-absorbent core of example 1 were 29.9g/g and 150 seconds, respectively, although the water absorption capacity and the absorption time of the water-absorbent core of comparative example 3, which are different from those of example 1 only in the cutting manner, were comparable to those of example 1, the water-absorbent core of comparative example 3 exhibited a delamination phenomenon after sufficient water absorption, which indicates that ultrasonic cutting can improve the connectivity between the layers of the water-absorbent core.

And differs from example 1 only in that the water absorption capacity and the absorption time of the absorbent core of example 9 using grass pulp as fluff pulp were 28g/g and 160 seconds, respectively, it is apparent that example 1 has not only a large water absorption capacity but also a fast absorption rate, which indicates that the use of wood pulp as fluff pulp can not only increase the water absorption capacity of the absorbent core but also increase the water absorption rate.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The preparation method of the water-absorbing core body is characterized by comprising the following steps:

loosening and carding the chemical fibers to form a fluffy cotton layer;

forming a first flow guide layer on the fluffy cotton layer, wherein the first flow guide layer comprises the following materials in percentage by mass: 70% -90% of fluff pulp and 10% -30% of hot-melt fibers;

forming a second flow guide layer on the water absorption layer to obtain a laminated body, wherein the second flow guide layer comprises the following materials in percentage by mass: 70% -90% of fluff pulp and 10% -30% of hot-melt fibers;

hot air penetration shaping is carried out on the laminated body, so that hot melt fibers in the first flow guide layer and the second flow guide layer are melted, and the fluffy cotton layer, the first flow guide layer, the water absorption layer and the second flow guide layer are connected together, so that the shaped laminated body is obtained; and

rolling and cooling the shaped laminated body, cutting by using ultrasonic waves, and fusing the hot melt fibers in the first flow guide layer and the second flow guide layer at the cut part to obtain a water-absorbing core body;

the chemical fiber comprises 3-70% of polyester fiber, polypropylene fiber and polyethylene fiber by mass;

the length of the hot-melt fibers of the first flow guide layer and the second flow guide layer is 3-8 mm, and the specification is 2-3D;

the technological parameters of the ultrasonic cutting are as follows: the cutting speed is 80-250 m/min, and the ultrasonic frequency is above 20000 Hz.

2. The method for preparing the water absorbent core according to claim 1, wherein the fluff pulp of the first flow guide layer and the second flow guide layer is crushed and sieved by a sieve with the diameter of 2.5-8 mm.

3. The method for manufacturing a water absorbent core according to claim 1, wherein the length of the fibers of the bulky cotton layer is 38mm to 64mm, and the specification of the fibers of the bulky cotton layer is 1.5D to 35D.

4. The method of making an absorbent core of claim 1 wherein said fluff pulp is wood pulp.

5. The method of making a water-absorbing core as in claim 1, wherein said hot melt fibers comprise polypropylene fibers and polyethylene fibers.

6. The method of making a water-absorbing core as recited in claim 1, wherein said step of through-air-setting said laminate is at a temperature of from 120 ℃ to 150 ℃.

7. The method for preparing a water-absorbing core according to claim 1, wherein the step of rolling and cooling the shaped laminate is specifically as follows: and performing air draft cooling on the shaped laminated piece while rolling, and enabling the relative humidity of the shaped laminated piece to be 3% -10% RH.

8. The method of making a water-absorbing core as recited in claim 1, further comprising the step of forming a plurality of said water-absorbing layers and a plurality of said second flow-directing layers in alternating arrangement on said second flow-directing layers prior to said step of through-air-setting said laminate.

9. A water-absorbent core obtained by the method for producing a water-absorbent core according to any one of claims 1 to 8.

10. Use of an absorbent core according to claim 9 in a core of a diaper or a core of a sanitary napkin.