JPH04218157A - Manufacture of disposable diaper - Google Patents

Abstract

PURPOSE:To produce disposable diapers economically having a pocket structure by a method wherein a part covering an absorbing core of a surface sheet is arranged in three layers so that the reversion of urine is prevented to reduce a feeling of wetting skin and uncomfortableness otherwise caused while allowing the concealing of feces discharged. CONSTITUTION:A first layer surface sheet 1A is made of a hydrophilic material formed in dimensions almost the same as an absorbing core 3 and is arranged to cover the top surface of the absorbing core 3. A second layer surface sheet 1B and a third surface sheet 1C are formed using a long-sized strip sheet identical to a rear sheet 2. The second layer surface 1B or one third layer surface sheet 1C employs a hydrophobic material and both side rims thereof are bonded securely on both side rims of the rear sheet 2. Here, a expandable elastic body 6 is arranged being stretched and fixed. A slit or a hole 4 is provided at the central area of both the sheets 1B and 1C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing disposable diapers, and particularly to a method for manufacturing disposable diapers economically and appropriately through simple processing. More specifically, the pocket structure prevents urine from returning from the absorbent core (wet back), reduces the feeling of tightness and discomfort on the skin that comes into contact with the diaper, and can also cover up human excreted feces. The present invention relates to a method for efficiently manufacturing a disposable diaper having the following properties using a simple method.

[Prior art and its problems] In recent years, disposable paper diapers have rapidly become popular in place of cloth diapers. One reason for this is that the absorbent core's waste storage capacity has been greatly improved and its convenience has become well known. However, conventional products are still insufficient in terms of preventing the leakage of excrement and eliminating the tightness and discomfort of the skin that comes into contact with the diaper.

By the way, many proposals have been made to prevent leakage from disposable diapers, and one example is Japanese Patent Laid-Open No. 62
This is disclosed in Japanese Patent No.-250201 and the like. The disposable diaper described above has an absorbent core arranged between a liquid-permeable top sheet and a liquid-impermeable back sheet, and has elastically contractible gasket cuffs and members called barrier cuffs on the side edges of the top sheet. It is a disposable diaper.

In this diaper, a double three-dimensional gather (barrier) is formed by attaching another set of elastically contractible barrier cuffs to the inside of the gathered left and right elastically contractible gasket cuffs. Therefore, human excrement is restrained and retained by the barrier cuffs raised on the inside, and is devised to prevent it from exceeding the outside, and the double three-dimensional gathers described above reduce leakage of excrement from the diaper. or was intended to delay.

However, the above diaper has the disadvantage that urine absorbed by the absorbent core returns to the top sheet and leaks out from the edge of the top sheet to the abdomen or back side. Because it comes into close and wide contact with the skin, the wearer is left with a feeling of tightness and discomfort.

Further, during manufacturing and processing, the above-described diaper has gasket cuffs and barrier cuffs raised by elastic members attached to their respective edges to form double three-dimensional gathers. Therefore, in order to attach the elastic member inside the cuff, it was necessary to fold back the edge of each cuff to form a tunnel, and to seal the elastic member in a stretched state inside the tunnel and fix it with adhesive. . This operation of folding back the cuff edge and the operation of enclosing the elastic member in a stretched state and gluing and fixing the elastic member to the edge are time-consuming and mechanically complex operations, and are a major hindrance to the processing process. Operations cannot be completed. Moreover, since it takes time and effort to attach another pair of barrier cuffs to the inside of the pair of gasket cuffs, there is also a drawback in that manufacturing efficiency is low.

[Objective of the invention] The present invention prevents the backflow of urine after urination (wetback) by a simple process, and prevents urine from seeping and leaking from the edge of the top sheet that contacts the diaper to the abdomen or back side. We aim to establish an economical and appropriate method for manufacturing disposable diapers that have a pocket structure that can eliminate skin irritation and reduce skin tightness and discomfort, as well as cover human excrement. It is something.

[Means for Solving the Problems] In order to achieve the above object, the present invention proposes the following diaper manufacturing method. That is, in a method for manufacturing a disposable diaper in which an absorbent core is disposed between a topsheet and a liquid-impermeable backsheet, a) the topsheet is partially made of three layers capable of covering the absorbent core; (b) Of the three layers of sheets, the first layer (lower layer) surface sheet is made of a hydrophilic material with approximately the same length as the absorbent core so as to cover the upper surface of the absorbent core. c) At least one of the second layer (middle layer) and third layer (top layer) topsheets is made of a hydrophobic material; d) and a plurality of topsheets are provided between the second layer topsheet and the third layer topsheet. After arranging the stretchable elastic body of the book in a stretched state along the longitudinal direction of the sheet and adhering and integrating it with the top sheet of the second layer and the third layer, e) the stretchable body avoiding the stretchable elastic body; in a lateral position and said second and third layers.
a slit or hole of a predetermined shape is provided in the central region of the top sheet of the layer; f) Thereafter, the top sheets of the second and third layers are superimposed on the first layer top sheet, and This is a method for manufacturing a disposable diaper that requires the above steps A to F to adhere the both side edges of either the layer or the top sheet of the third layer onto the both side edges of the back sheet.

[Specific Description of the Invention] Figure 1 is a flow diagram showing an overview of the manufacturing method of the present invention, Figure 2 is a plan view showing an example of a product produced by the method of the present invention, and Figure 3 is a sectional view of the product. be. The method of the present invention will be specifically explained below with reference to the drawings.

In the drawings, numeral 1 is the top sheet, 2 is the back sheet, and 3 is the top sheet.
indicates an absorbent core interposed between a top sheet and a back sheet. As described later, the top sheet 1 is formed of three sheets that are partially overlapped in three layers and can cover the absorbent core 3. The bottom layer of these three sheets, that is, the first layer surface sheet 1A is made of a hydrophilic material formed to have approximately the same length as the absorbent core 3, and is arranged so as to cover the upper surface of the absorbent core 3. Set up

The absorbent core 3 covered with the first layer surface sheet 1A is
These are arranged at regular intervals along the longitudinal direction on the back sheet 2 formed from a liquid-impermeable elongated material.

Then, the back sheet 2 consisting of a long strip-shaped sheet is pulled out from the winding (not shown), and the first layer top sheet 1A is
The second layer (described later) is transferred to the absorbent body 3 covered with
Transfer to the adhesion process of the middle layer) top sheet 1B and the third layer (upper layer) 1C.

The second layer topsheet 1B and the third layer topsheet 1C are formed using elongated belt-shaped sheets in the same way as the backsheet 2 described above. At least one of the second layer or the third layer surface sheet is made using a hydrophobic material. Also, the second
At least one of the layer and the topsheet of the third layer may be formed of a belt-shaped sheet having a width equivalent to that of the product diaper, and the other may have a width smaller than that. Then, the above-mentioned two sheets are pulled out from the winding (not shown) and supplied to the next hole punching process. A slit or hole 4 of a predetermined shape is formed in the area. When making the above-mentioned holes, a plurality of stretchable elastic bodies 5 are stretched along the longitudinal direction of the sheets between the second layer topsheet and the third layer topsheet in a pre- or post-process. After arranging them, they are partially adhered to the surface sheets of the second and third layers using a hot melt adhesive, heat sealing, ultrasonic sealing, or the like. Then, a slit or elongated hole 4 is made by cutting out an appropriate shape having a predetermined length and width between the stretchable elastic bodies or at a lateral position avoiding the stretchable elastic bodies.

The second layer (middle layer) topsheet 1B and the third layer (upper layer) topsheet 1C configured in this way are transferred to the first layer topsheet on the backsheet 2 via an appropriate conveyance device (not shown). After being superimposed on the absorbent core 3 covered with 1A, it is supplied to the bonding process with the back sheet. That is, after superimposing the second layer and third layer topsheets on the first layer topsheet, the both side edges of either the second layer or the third layer topsheet are placed on the backsheet. Glue and fix on both side edges. At that time, the stretchable elastic body 6 is arranged and fixed in a stretched state between the side edges of the back sheet and the second layer or third layer top sheet, if necessary. After fixing, the above-mentioned top sheet and back sheet are cut at predetermined intervals in the longitudinal direction according to the dimensions of the finished product to obtain a finished product. As mentioned above, the winding of each sheet, the distributing and feeding device for the absorbent core, the sheet conveyance line, the sheet punching device, the bonding device, etc. are not shown in the drawings.

The product cut in this manner has the stretchable elastic bodies 5 and 6 contracted to be in the state shown in FIG. 4. Below, the second
The details of the diaper shown in FIGS. 4 to 4 will be explained as follows.

An absorbent core 3 is interposed in the central region between the liquid-permeable first layer top sheet 1A and the liquid-impermeable back sheet 2. The overall planar shape of the absorbent core is approximately I-shaped, that is, an hourglass shape, but a rectangular absorbent core that is not constricted at the center may also be used. Then, at least one of the top sheet 1 and the back sheet 2 is extended to form side flaps 7 on both sides so as to protrude laterally from both widthwise edges of the absorbent core. A plurality of elastic elastic bodies 6 are disposed in parallel on the side flaps in a stretched state along the longitudinal direction of the absorbent core, and are partially integrally adhered to the top sheet 1 and the back sheet 2. Thus, gathers 8 are formed by the side flaps and the stretchable elastic body. At this time, the center portion of the side flap is cut off inward to form a crotch portion 9 including the absorbent core 3 and the sheets 1 and 2 covering the front and back sides of the absorbent core 3 in the center region. The widths at both ends in the longitudinal direction of the front and back sheets are made wider than the width at the crotch area, thereby forming front and rear waist parts 10 and 11 that can surround the wearer's abdomen and back.

A pair of concave notches 12 for leg holes are formed in the inwardly constricted portion forming the opposite side edges in the width direction of the crotch area, and a side flap and an elastic material are attached along the inner edges of the concave notches. A leg gather 8 is formed by this. Furthermore, fastening tapes 13 are attached to both ends of the rear waist, and a front reinforcing tape 14 is attached to the front waist.

What is indicated by the reference numeral 15 is the waist gather. By the way, in the diaper manufactured by this method, the top sheet 1 is formed of three layers as described above. Among these three-layer sheets, a slit or hole 4 for water permeation is formed in the central region of the second and third layer sheets, and this slit or hole allows water to be excreted by the contraction of the stretchable elastic body 5. It functions as a pocket where stool can be stored and concealed. That is, at the four sides of the slit or hole or at least at the lateral positions, stretchable elastic bodies 5 that apply a contractile force in the direction of opening the pocket opening are integrally bonded to the second and third layer sheets in a stretched state. Therefore, when this stretchable elastic body is contracted, the topsheets of the second and third layers are lifted from the topsheet of the first layer, as shown in FIG. A pocket space is formed between the topsheet and the second layer topsheet to accommodate and conceal the stool.

Therefore, when this diaper is worn, the hydrophilic part that comes into contact with the skin after urination and causes discomfort can be confined to the limited area exposed from the pocket opening, and the other areas outside the four peripheries of the pocket are The second or third layer of hydrophobic material can keep waste away from the skin, thus preventing urine from backing up (wetback) from the absorbent core. Furthermore, it is possible to prevent the possibility of leakage from the edge of the hydrophilic first layer surface sheet to the belly or back side, thereby reducing the tightness and discomfort of the skin that comes into contact with the diaper.

Next, some examples of disposable diapers manufactured by the method of the present invention will be shown. Figures 5 and 6 show that no gathers are provided around the leg holes, and between the topsheets 1B and 1C of the second and third layers so that they protrude upward from both sides in the width direction of the absorbent core. This is an example showing a diaper in which a pocket is formed by an elastic body 5 attached to a diaper. Other than that, the configuration is the same as that of the diaper described above, so the same members are denoted by the same reference numerals, and redundant explanation of the configuration will be omitted. 7 and 8 show the second and third layer topsheets 1B and 1C at positions close to both sides of the pocket.
This shows an example in which the auxiliary absorbent body 16 is sandwiched between the two. The auxiliary absorbent body in this case functions to absorb excrement that is accidentally excreted outside the pocket opening or that may overflow from the pocket.

The position and shape of the slit or hole 4 are not limited to those shown in the embodiment described above. For example, as shown in FIGS. 9 and 10, a stretchable elastic body 6 is provided between the topsheets 1B and 1C of the second and third layers, and then A plurality of rows of cut-out holes 4 can be made in the area, and the first layer top sheet and the second layer top sheet can be partially bonded between the cut holes. In addition, the shape of the slit or hole is not limited to a simple long hole, but can also be T-shaped.
It may be Y-shaped or cross-shaped.

In the case of diapers for infants, the length of the product is generally 470 mm.
~490mm, and the width of the absorbent core 3 is 80~1
It is often formed to 80 mm. The opening width of the slit or hole is 1/6 to 1/1/2 of the width of the absorbent core 3.
The length of the slit is 1/3 of the product length.
~2/3 is appropriate. Specifically, when using an absorbent core with a width of 150 mm and a length of 430 mm, the opening width of the hole is 25 to 50 mm and the length is 200 to 350 mm.

Various other design changes can be made without departing from the spirit of the invention.

The basic structure of the diaper to which the method of the present invention is applied has been described above, and the materials of each component constituting the diaper will be briefly explained below.

First, the absorbent core 3 is placed between the front and back double-sided sheets 1 and 2.
Usually, a laminate of absorbent sheets such as tissue paper or dry pulp nonwoven fabric is used on the top and bottom surfaces.
The space between the upper and lower absorbent sheets consists of two or more layers of absorbent fiber layers such as flap pulp and rayon. Further, superabsorbent granules may be arranged between each layer of the absorbent core. The superabsorbent granules herein refer to commonly known superabsorbent polymer particles alone or granules in which activated carbon, carboxymethyl cellulose, zeolite, etc. are mixed.

As the hydrophobic material used in the present invention, hydrophobic nonwoven fabrics using polypropylene fibers, polyester fibers, polypropylene polyethylene composite fibers, polyester polyethylene composite fibers, etc. are often used. Hydrophilic treatment is applied to the part that contacts the wearer's crotch urinary position to provide water permeability. Instead of this hydrophobic non-woven fabric, we used a perforated plastic sheet with small holes in the urinating position, or used a hydrophilic dry non-woven fabric that was treated to be water-repellent in areas other than those that come in contact with the wearer's urinating position. things can be used.

As the liquid-impermeable back sheet, polyethylene film, hydrophobic nonwoven fabric, etc. can be used.

The stretchable elastic body 5 or 6 disposed between the top sheets of the second layer and the third layer and between the front and back sheets is made of thread, string, or band-like material made of natural or synthetic rubber, urethane, etc. This is fixed between the front and back sheets using an adhesive, heat sealing, ultrasonic sealing, or the like.

[Effects of the Invention] As explained above, in the disposable diaper manufactured by the method of the present invention, the top sheet is partially formed of a three-layer sheet that can cover the absorbent core, and Of the sheets in the layer, the first layer (lower layer) top sheet is made of a hydrophilic material with approximately the same length as the absorbent core and is attached to cover the upper surface of the absorbent core, the second layer (middle layer) and the third layer At least one of the surface sheets of the layer (upper layer) is made of a hydrophobic material, and the second layer surface sheet and the third layer surface sheet are made of a hydrophobic material.
After arranging a plurality of stretchable elastic bodies in a stretched state along the longitudinal direction of the topsheet between the topsheet and the topsheet and adhering and integrating them with the topsheet of the second layer and the third layer, the above-mentioned A slit or hole of a predetermined shape is provided in the central region of the topsheet of the second layer and/or the third layer at a lateral position avoiding the stretchable elastic body, and then the second layer Then, a third layer top sheet is superimposed on the first layer top sheet, and both side edges of either the second layer or the third layer top sheet are adhered onto both side edges of the back sheet. Therefore, the slits or holes for water permeation provided in the central areas of the second and third layer sheets can accommodate and cover up human excrement by the contraction of the stretchable elastic body. It functions as a pocket that can be used. The part that comes into contact with the skin after urinating can be confined to a limited area that is opened as the pocket, and the other four outer circumferences of the pocket are made of a second or third layer of hydrophobic material to remove excrement from the skin. Since it can be separated from the absorbent core, it is possible to prevent urine from flowing back from the absorbent core (wet back). Moreover, it also prevents the possibility of leakage from the edge of the hydrophilic first layer surface sheet to the belly or back side.
This can reduce the tightness and discomfort of the skin that comes into contact with the diaper.

Moreover, the present invention is similar to a conventional diaper in which gasket cuffs and barrier cuffs are raised up by elastic members attached to each edge to form a double three-dimensional gather, but the edges of the cuff are folded back to form a tunnel shape. The above-mentioned elastic member is sealed in a stretched state inside the tunnel and fixed with adhesive, and another set of elastically contractible barrier cuffs is placed separately inside the gathered left and right elastically contractible gasket cuffs. There is no need to paste it. The method of the present invention uses three partially superimposed topsheets that can cover the upper surface of the absorbent core,
Simply make a slit or hole in the center area of the topsheets of the second and third layers, place a stretchable elastic body between the topsheets of the second and third layers, and then paste them together. , it is possible to produce a disposable diaper with a pocket structure in the central region of the diaper. Therefore, it has the industrial effect of being able to manufacture diapers economically and efficiently with simpler processing than conventional methods.

[Brief explanation of the drawing]

Figure 1 is a flow diagram showing an overview of the manufacturing method of the present invention, Figure 2 is a plan view showing an example of a product produced by the method of the present invention, Figure 3 is a sectional view of the product, and Figure 4 is FIGS. 5 to 10 are plan views and cross-sectional views showing other examples of disposable diapers manufactured by the method of the present invention. It is a diagram. 1: Top sheet, 1A: First layer top sheet, 1B: Second layer
Layer surface sheet, 1C: Third layer surface sheet, 2: Back sheet, 3: Absorbent core, 4: Slit (hole) 5, 6: Stretchable elastic body, 7: Side flap, 8: Leg gathers, 9:
Crotch area, 10: Front waist, 11: Rear waist, 1
2 Concave notch for leg hole, 13: Fastening tape, 14: Front reinforcing tape, 15: Waist gathers, 16: Auxiliary absorbent patent applicant Honshu Paper Co., Ltd. agent Patent attorney Naoe Ashida

Claims (1)

[Claims] 1. A method for manufacturing a disposable diaper in which an absorbent core is disposed between a topsheet and a liquid-impermeable backsheet, comprising: (a) a partial portion of the topsheet that can cover the absorbent core; (b) Of the three layers, the first layer (lower layer) surface sheet is made of a hydrophilic material with approximately the same length as the absorbent core, and the upper surface of the absorbent core is c) At least one of the second layer (middle layer) and third layer (upper layer) topsheets is made of a hydrophobic material, and d) and the second layer topsheet and the third layer topsheet In between, a plurality of stretchable elastic bodies are arranged in a stretched state along the longitudinal direction of the sheet to form the second layer and the third layer.
After adhering and integrating the topsheets of the layers, e) slits or holes of a predetermined shape are formed at lateral positions avoiding the stretchable elastic body and in the central regions of the topsheets of the second and third layers. f) After that, the top sheets of the second layer and the third layer are superimposed on the top sheet of the first layer, and both side edges of the top sheet of either the second layer or the third layer are A method for manufacturing a disposable diaper, characterized in that: is adhered to both side edges of a back sheet.