JP2006152485A - Apparatus for processing tow and humor absorbing article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide apparatus for processing tow evenly widening tow. <P>SOLUTION: The apparatus comprises an opening device 18 extending tow T by difference of peripheral velocity of a first nip roll 11 and a second nip roll 12, and shrinking the tow by the difference of peripheral velocity of the second nip roll 12 and a third nip roll 13. And the apparatus comprises a widening box 55 widening the tow by the action of air by sucking the tow T opened by the opening device 18 through an aperture 56 directing horizontal direction. The apparatus is set so that the tow flows from the first nip roll 11 to the aperture 56 on a horizontal line of the aperture 56, and set the shrinking forces acting on the upper and the lower planes of the tow flowing through the opening device 18 substantially equal to each other by forming a groove 15 on the peripheral face of the second nip roll 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a fiber assembly made of tow that can be used as an absorbent for body fluid absorbent articles such as paper diapers, sanitary napkins, urine-absorbing pads, incontinence pads, etc. And tow processing equipment and body fluid absorbent articles.

  In recent years, the present inventors have developed a fiber assembly comprising a tow as a processed tow obtained by opening and widening a tow, such as a paper diaper, a sanitary napkin, a urine absorption pad, an incontinence pad, etc. It has been found that it is preferable to use it as an absorbent material for adhesive articles.

And conventionally, the tow T has been spread and widened with the processing equipment 50 as shown in FIG.
In other words, in the present facility 50, first, the tow T is expanded and contracted by the fiber opening device 58 to be opened. The present opening device 58 includes a first nip roll 51, a second nip roll 52, and a third nip roll 53 that are arranged in the vertical direction, and extends the tow T due to a difference in peripheral speed between the first nip roll 51 and the second nip roll 52. The tow T contracts due to the difference in peripheral speed between the second nip roll 52 and the third nip roll 53.
In the spreader 58, the opened tow T flows in the duct 54 installed below the spreader 58 by the suction force from the widening box 55 installed downstream of the duct 54. The flow direction of the tow T changes from the lower direction to the horizontal direction (in the illustrated example, from the right side to the left side in the drawing) because the duct 54 has an L shape. The tow T whose flow direction is horizontal is sucked into the widening box 55 through the opening 56 facing the horizontal direction, and is widened by air in the widening box 55. In addition, this processing equipment and the absorber using the fiber assembly which consists of a tow | toe obtained by this processing equipment are what the present inventors discovered, and it is thought that well-known prior literature does not exist. .

  In the above processing equipment 50, the flow direction of the tow T is changed from the downward direction to the horizontal direction by the duct 54 for the following reason. That is, the opened tow T is very soft and fluffy. Therefore, when the opened tow T is sucked into the widening box 55 in a state of flowing in an oblique direction with respect to the opening 56, the tow T is caught on the periphery of the opening 56. And by this catching, it will enter in the widening box 55 in the state cut | disconnected or pulsated, and it becomes impossible to expand uniformly.

  However, even with this processing equipment 50, the tow T may contact the duct 54 when the flow direction is changed from the lower direction to the horizontal direction, and this contact causes the tow T to be opened. Cutting and pulsation may occur, and it may become impossible to uniformly widen.

  And this means that the bodily fluid absorbent article which used the processed material obtained with the processing equipment 50 as an absorbent does not have the expected performance.

  SUMMARY OF THE INVENTION The main problem to be solved by the present invention is to provide a tow processing equipment and a body fluid-absorbing article that can uniformly widen the tow.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
A fiber opening device that stretches the tow by a circumferential speed difference between the first nip roll and the second nip roll, and shrinks the tow by a circumferential speed difference between the second nip roll and the third nip roll;
A tow processing facility having a widening box that sucks the tow opened by the opening device through an opening facing in the horizontal direction and widens it by air,
The tow flows on a horizontal line of the opening from at least the first nip roll to the opening;
A groove is formed in the peripheral surface of the second nip roll, and the torsional force acting on the upper surface and the lower surface of the tow flowing through the opening device is substantially equal. Processing equipment.

[Invention of Claim 2]
A widening box that widens the tow sucked through an opening facing in the horizontal direction by air; and
A first roll device in which a tow flows between a pair of first nip rolls and an amount of tow sucked into the widening box is determined according to a peripheral speed of the first nip rolls;
A tow from the first roll device flows between a pair of second nip rolls, the second nip roll has a higher peripheral speed than the first nip rolls, and the tow is extended;
And the tow from this 2nd roll apparatus flows between a pair of 3rd nip rolls, and this 3rd nip roll has a peripheral speed slower than the said 2nd nip roll, and the 3rd roll to which a tow contracts. A device for opening the tow,
A tow processing facility having
The first nip roll, the second nip roll, and the third nip roll are arranged so that the respective pairs of rolls are vertically aligned, and all the nip rolls are positioned on the horizontal line of the opening,
Grooves are formed on at least one of the peripheral surfaces of the second nip roll so that the expansion and contraction forces acting on the upper and lower surfaces of the tow flowing between the nip rolls are substantially equal. A tow processing facility characterized by

[Invention of Claim 3]
A bodily fluid absorbent article, wherein the processed tow obtained by the facility according to claim 1 or 2 is used as an absorbent.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes a tow | toe processing equipment and a body fluid absorptive article which can widen a tow | toe uniformly.

Embodiments of the present invention will be described below.
[Use]
The fiber assembly made of the tow obtained by opening and widening the tow by the processing equipment of the present invention is, for example, a paper diaper, a sanitary napkin, a urine picking pad as it is or mixed with an absorbent polymer. It can be used as an absorbent for body fluid absorbent articles such as incontinence pads. In the following description, the case where it is used as an absorbent material is simply abbreviated as an absorption application.

[Toe]
The tow of the present invention means a fiber bundle. As the constituent fiber of this tow, for example, polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.) It can be illustrated.

  However, when it is set as an absorption use, it is preferable to use a cellulose and a cellulose ester. Among these, as cellulose, cellulose derived from plants such as cotton, linter, and wood pulp, bacterial cellulose, and the like can be used. Further, as cellulose, regenerated cellulose such as rayon can be used, and the regenerated cellulose may be a spun fiber. Further, as the cellulose, continuous fibers that can be regarded as substantially infinite length, fibers having a long diameter of several millimeters to several centimeters (for example, 1 mm to 5 cm), and particle diameters of several microns (for example, 1 to 100 μm). Various lengths, sizes and shapes, such as finely powdered fibers, can be used. The cellulose may be fibrillated like beating pulp.

  On the other hand, examples of the cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate, mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate. Cellulose ester derivatives such as caprolactone-grafted cellulose ester can be used. Of course, these cellulose esters can be used alone or in admixture of two or more. However, as the cellulose ester, an organic acid ester (for example, an ester with an organic acid having about 2 to 4 carbon atoms) is preferably used, and cellulose acetate is more preferably used. Cellulose acetate can easily adjust the porosity, and is very suitable for absorption applications.

  The viscosity average degree of polymerization of the cellulose ester is preferably 10 to 1000, more preferably 50 to 900, and particularly preferably 200 to 800. The average substitution degree of the cellulose ester is preferably 1.00 to 3.00, more preferably 1.00 to 2.15, and particularly preferably 1.10 to 2.00. . The average degree of substitution of the cellulose ester can be selected from the viewpoint of enhancing biodegradability. Furthermore, although the acetylation degree of a cellulose acetate is about 43 to 62% normally, it is preferable that it is 30 to 50% from a viewpoint of biodegradability.

  The tow constituent fiber may contain various additives such as a heat stabilizer, a colorant, an oil agent, a yield improver, a whiteness improver, and the like. For example, when it is used for absorption, it is preferable that the above-described oil agent is effective for skin care that also serves as water repellency and is applied to the tow constituent fibers.

  In the case of absorption, the fineness of the tow constituent fibers is preferably 1 to 16 denier, more preferably 1 to 10 denier, and particularly preferably 2 to 8 denier.

  In the case of absorption, the tow constituent fiber may be a non-crimped fiber, but is preferably a crimped fiber. When the crimped fiber is used, it is possible to obtain an absorbent body that is bulky and lightweight and has high unity due to entanglement between the fibers.

  The crimped degree of the crimped fiber is preferably 5 to 75 per inch (2.54 cm), more preferably 10 to 50, and particularly preferably 15 to 50. . This crimped fiber is usually crimped uniformly.

  The cross-sectional shape of the tow constituent fiber is not particularly limited. For example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape, etc.), a hollow shape, and the like can be exemplified.

  The tow constituting fibers can be made into tows (fiber bundles) by bundling, for example, about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. .

  The tow formed as described above is excellent in air permeability due to weak entanglement between fibers, but is easy to sag. Therefore, for the purpose of preventing sagging and maintaining a wide gap, it is preferable to bond or fuse the contact portion of the fiber with a binder.

  Examples of the binder include ester plasticizers such as triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, and triethyl citrate, and various resin adhesives, particularly thermoplastics. The resin adhesive can be used.

  The thermoplastic resin is a resin that exhibits an adhesive force by melting and solidifying, and includes a water-insoluble or hardly water-soluble resin, and a water-soluble resin. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or poorly water-soluble resins include polyethylene, polypropylene, ethylene-propylene copolymers, olefinic homo- or copolymers such as ethylene-vinyl acetate copolymers, polyvinyl acetate, polymethyl methacrylate, methacrylic. Acid methyl-acrylic acid ester copolymer, acrylic resin such as copolymer of (meth) acrylic monomer and styrene monomer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, polystyrene, styrene monomer ( Styrenic polymers such as copolymers with (meth) acrylic monomers, optionally modified polyesters, polyamides such as nylon 11, nylon 12, nylon 610, nylon 612, rosin derivatives (eg, rosin esters). , Hydrocarbon resins (eg terpene resins, Pentadiene resins, petroleum resins, and the like.), A hydrogenated hydrocarbon resin, or the like can be used. These thermoplastic resins can be used alone or in combination of two or more.

  As the water-soluble resin, various water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, vinyl monomers, and copolymerizable monomers having a carboxyl group, a sulfonic acid group or a salt thereof, Vinyl-based water-soluble resins such as copolymers, acrylic water-soluble resins, polyalkylene oxide, water-soluble polyester, water-soluble polyamide, and the like can be used. These water-soluble resins can be used alone or in combination of two or more.

  Various additives such as stabilizers such as antioxidants and ultraviolet absorbers, fillers, plasticizers, preservatives, and antifungal agents can be added to the thermoplastic resin.

〔Processing facilities〕
In FIG. 2, the processing equipment 10 of this Embodiment was shown. The processing facility 10 is mainly composed of a fiber opening device 18, a duct 14, and a widening box 55.
The opening device 18 is mainly composed of a first roll device, a second roll device, and a third roll device. The first roll device, the second roll device, and the third roll device each include at least a pair of first nip rolls 11, a pair of second nip rolls 12, and a pair of third nip rolls 13, respectively. Each separate or uniform drive source is provided.

  In the present fiber opening device 18, the first to third nip rolls 11, 12, and 13 are each paired up and down. The tow T as a raw material is nipped between all the nip rolls. The tow T is flowed (conveyed) from the right side to the left side in accordance with the rotation of the nip rolls 11, 12, and 13.

  In the fiber opening device 18, the second nip roll 12 has a higher peripheral speed than the first nip roll 11, and the third nip roll 13 has a lower peripheral speed than the second nip roll 12. . Therefore, in the fiber opening device 18, the tow T is stretched (tensed) due to the difference in peripheral speed between the first nip roll 11 and the second nip roll 12, and the tow is increased due to the difference in peripheral speed between the second nip roll 12 and the third nip roll 13. T is contracted (relaxed). Due to this expansion and contraction, the tow T is opened and becomes very weak. The peripheral speed refers to the speed at which the peripheral surface, that is, the roll surface moves. This peripheral speed is determined by, for example, the rotational speed and diameter of the roll.

  Further, in the present opening device 18, all the nip rolls are arranged on the horizontal line (same height) of the opening 56. That is, the tow T flows on the horizontal line of the opening 56 from the first nip roll 11 to the opening 56. Therefore, the opened tow T is caught in the peripheral portion of the opening 56, and there is no possibility of being cut or pulsated, and the tow T is uniformly widened in the widening box 55.

  However, if the tow T simply allows the first nip roll 11 to the opening 56 to flow on the horizontal line of the opening 56, the stretching force and the contracting force acting on the upper surface of the tow T (simply expansion and contraction). There is a possibility that the stretching force acting on the lower surface of the tow T is not equal due to the influence of gravity. If the stretching force is not equal, the fiber is not spread uniformly, and naturally the subsequent widening may not be made uniform. Therefore, in the present fiber opening device 18, as shown in FIG. 3, a groove 15 is formed on the peripheral surface of the second nip roll 12 so that the expansion and contraction forces are substantially equal.

  The depth, width, area, direction, shape, and the like of the groove 15 are not particularly limited. From the viewpoint of equalizing the stretching force, it can be designed as appropriate. Moreover, this groove | channel 15 does not need to be formed in both of a pair of rolls. It may be formed only on either one of the rolls. In the illustrated example, the groove 15 is not formed in the upper roll 12A, but is formed only in the lower roll 12B. In the illustrated example, the groove 15 is formed in the flow direction of the tow T, and about half of the total area is the groove 15, so the groove 15 is formed only on the lower roll 12B. The stretching force acting on the tow T on the side in contact with the lower roll 12B is weakened to cancel the influence of gravity. However, for example, when the groove 15 is formed in an oblique direction other than the flow direction of the toe T, for example, the direction of the stretching force acting on the toe T on the side in contact with the roll on which the groove 15 is formed May become stronger. Therefore, it may be better to form the groove 15 only in the upper roll 12A. Of course, the combination of the grooves of the upper roll 12A and the grooves of the lower roll 12B can make the stretching force uniform.

  In the present embodiment, there is no particular limitation on how much the fiber opening is performed, that is, how much force is used for stretching and stretching. Since the degree of opening is a factor of fiber density, it may be set appropriately according to the application.

  The tow T opened in the above manner is located in the side of the opening device 58, in the illustrated example, on the left side of the sheet, and on the side of the duct 14 in the illustrated example. It flows by the suction force from the widening box 55 installed on the left side (air conveyance). The duct 14 has a linear shape along the horizontal line of the opening 56, and there is no possibility of coming into contact with the opened tow T.

  The tow T that has flowed through the duct 14 is sucked into the widening box 55 through the opening 56 that faces in the horizontal direction. The amount of tow T sucked is determined according to the peripheral speed of the first nip roll 11. That is, the amount increases as the peripheral speed of the first nip roll 11 increases, and decreases as the peripheral speed decreases.

  The tow T sucked into the widening box 55 is widened by air such as compressed air and becomes a fiber assembly made of tows having a desired width and density. In the widening box 55, how to widen the tow T is not particularly limited. For example, the width can be increased to 100 to 2000 mm, preferably 150 to 1500 mm.

  As described above, the processing equipment 10 according to the present embodiment is configured such that the nip rolls are three sets (11, 12, 13), and the tow T is expanded and contracted once. However, the purpose is not limited to this. The number of nip rolls may be increased, and the tow T may be stretched and contracted two times, three times, four times or more.

[Body fluid absorbent article]
The bodily fluid absorbent article of the present embodiment uses a fiber assembly made of tow obtained by the above processing equipment as an absorbent material. If it is used as an absorbent material, for example, an excellent effect as described later can be expected, so use in various places (as a member) can be considered. Specifically, for example, a conventional absorbent article, that is, a body fluid absorber formed by wrapping an absorbent material such as cotton-like pulp or synthetic pulp with crepe paper between a top sheet and a back sheet. The use of the body fluid absorbent article in place of an absorbent material such as cotton-like pulp or synthetic pulp can be exemplified.

[Characteristics of fiber assembly made of tow]
The fiber assembly made of tow in the present specification refers to a fiber assembly produced from tow serving as a raw material, that is, obtained by opening and widening the tow serving as a raw material. Since the fiber assembly made of this tow has a higher porosity than pulp or the like, when it is used for absorption, an improvement in absorption speed can be expected.

  In addition, since the fiber assembly made of tow is a long fiber, there is no possibility that it is separated (divided) into two in the fiber flow direction. Therefore, for example, in the case of absorption application, if the flow direction of the fiber is the longitudinal direction (front-rear direction), the absorbent body at the center in the longitudinal direction, i.e., the leg-around portion, is also applied to the front-rear end by the movement of the wearer Therefore, a side leakage prevention effect can be expected.

  Furthermore, the fiber assembly made of tow has a characteristic that liquid easily diffuses in the fiber flow direction, but liquid hardly diffuses in a direction perpendicular to the fiber flow direction. Therefore, for example, in the case of absorption application, if the flow direction of the fiber is the longitudinal direction (front-rear direction), the body fluid diffuses rapidly in the longitudinal direction, and the entire surface of the absorber is effectively utilized.

  In addition, the fiber aggregate made of tow has the property that when the fiber density is low, the liquid retainability is excellent, and when the fiber density is high, the liquid diffusibility is excellent. Therefore, for example, in the case of absorption application, if both side end portions of the absorber are made lower in density than the center portion in the width direction, body fluid diffuses quickly in the center portion in the width direction of the absorber, and quick diffusibility The body fluid retention is improved at both side end portions that do not need to be provided, and the most suitable characteristics are imparted according to each part. However, if the fiber density at both end portions is too low, there is a risk of distortion in the width direction of the absorbent body. In addition, if the fiber density at both end portions is too high, the wearer may feel uncomfortable. Therefore, consideration for these points is necessary.

  The present invention is to open and widen a tow, for example, a fiber assembly made of tow that can be used as an absorbent such as a paper diaper, a sanitary napkin, a urine absorption pad, an incontinence pad, etc. Applicable as processing equipment.

It is a flowchart of the conventional processing equipment. It is a flowchart of the processing equipment of this Embodiment. FIG. 3 is a schematic cross-sectional view taken along line II in FIG. 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,50 ... Processing apparatus 11, 12, 13, 51, 52, 53 ... Nip roll, 14, 54 ... Duct, 18, 58 ... Opening device, 55 ... Widening box, 56 ... Opening, T ... Tow.

Claims (3)

A fiber opening device that stretches the tow by a circumferential speed difference between the first nip roll and the second nip roll, and shrinks the tow by a circumferential speed difference between the second nip roll and the third nip roll;
A tow processing facility having a widening box that sucks the tow opened by the opening device through an opening facing in the horizontal direction and widens it by air,
The tow flows on a horizontal line of the opening from at least the first nip roll to the opening;
A groove is formed in the peripheral surface of the second nip roll, and the torsional force acting on the upper surface and the lower surface of the tow flowing through the opening device is substantially equal. Processing equipment. A widening box that widens the tow sucked through an opening facing in the horizontal direction by air; and
A first roll device in which a tow flows between a pair of first nip rolls and an amount of tow sucked into the widening box is determined according to a peripheral speed of the first nip rolls;
A tow from the first roll device flows between a pair of second nip rolls, the second nip roll has a higher peripheral speed than the first nip rolls, and the tow is extended;
And the tow from this 2nd roll apparatus flows between a pair of 3rd nip rolls, and this 3rd nip roll has a peripheral speed slower than the said 2nd nip roll, and the 3rd roll to which a tow contracts. A device for opening the tow,
A tow processing facility having
The first nip roll, the second nip roll, and the third nip roll are arranged so that the respective pairs of rolls are vertically aligned, and all the nip rolls are positioned on the horizontal line of the opening,
Grooves are formed on at least one of the peripheral surfaces of the second nip roll so that the expansion and contraction forces acting on the upper and lower surfaces of the tow flowing between the nip rolls are substantially equal. A tow processing facility characterized by   A bodily fluid absorbent article, wherein the processed tow obtained by the facility according to claim 1 or 2 is used as an absorbent.

Images