JPH04166151A - Surface, sheet of absorbent article - Google Patents

Abstract

PURPOSE:To make a surface sheet softer to touch on skin by using a surface sheet made up of unwoven cloth to which hot melting fibers are fusion-bonded, the unwoven cloth having a middle layer with the density thereof the highest at skin touching area, an upper layer with the density thereof lower than that of the middle layer and a lower layer with the density thereof lower than that of the middle layer composed of fibers with the largest relative denier. CONSTITUTION:First-third fiber layers 14, 15 and 16 composing a surface sheet 4 are made up of an unwoven cloth to which hot melting fibers are fusion bonded and the unwoven cloth herein used is preferably a melt-blow unwoven cloth as mentioned below. The second fiber layer 15 as a middle layer is made of fibers 15a and the highest in density to maintain the strength of the surface sheet 4. The first fiber layer 14 as an upper layer is made of fibers 14a and is lower in density than the second fiber layer 15. The surface sheet 4 is made soft to touch on skin while kept looking like a cloth. The third fiber layer 16 as lower layer is made of fibers 16a and is lower in density than the second fiber layer 15. The fibers 16a are the ones with denier thereof larger relatively than the fibers 14a and 15a. Thus, the strength of the surface sheet can be improved without impairing the intrinsic function of the surface sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a top sheet of a disposable absorbent article for treating body fluids, and more particularly, the present invention relates to a top sheet of a disposable absorbent article for treating body fluids, and more specifically, the top sheet has a liquid conduction pipe and is made of a nonwoven fabric having a multilayer structure. Regarding the seat.

(Prior art, problems to be solved by the invention) Conventionally, this type of surface sheet has been made with hydrophobic materials for the purpose of reducing the feeling of body fluid wetness on the wearer's skin and relatively increasing the permeability of body fluids. It is known that a nonwoven fabric has openings arranged in a given pattern. However, the openings in this top sheet have a planar structure, and the lower surface of the skin contact area extending between each opening directly contacts the upper surface of the absorbent core. Therefore, when body pressure is applied to the core that has absorbed body fluids, or when the core expands after absorbing body fluids and comes into pressure contact with the top sheet, body fluids leak from the core through the openings onto the top surface of the top sheet. However, the intended purpose cannot be fully achieved.

On the other hand, a plastic film is used as a top sheet for the purpose of eliminating defects in the top sheet, and a given pattern of openings is arranged in the plastic film, and liquid guide pipes are formed that extend downward from the periphery of each of these openings. It is known that it has

This top sheet reduces the contact area with the wearer's skin and the feeling of body fluid wetness on the skin, and has relatively high body fluid permeability (
The purpose of doing so can be achieved. but,
This topsheet generally has a slimy texture and gloss characteristic of plastic films, and is therefore often disliked by users of wearing articles.

Therefore, in the present invention, the top sheet is made of a non-woven fabric with heat-fusible fibers fused to it, and a part of this non-woven fabric forms a liquid guide tube with excellent capillary action, and this non-woven fabric is used at least in the skin contact area. The present invention attempts to solve the problems of the prior art by forming a multilayer structure consisting of first to third fiber layers.

(Means for Solving the Problems) In order to solve the above problems, the gist of the configuration of the present invention is as follows.

The present invention is directed to topsheets in absorbent articles for treating body fluids such as disposable diapers and sanitary napkins.

In the present invention, the top sheet has an upper surface and a lower surface opening, and forms liquid guide tubes extending downward and arranged, and a skin contact area continuous with the periphery of the upper surface opening of these liquid guide tubes. There is. Such a top sheet is composed of a nonwoven fabric to which thermofusible fibers are fused. At least in the skin contact area, this nonwoven fabric has the highest density intermediate layer (second fiber layer) made of fibers of 0.001 to 0.5 d (denier); an upper layer (first fiber layer) with lower density than the layer, and 0.05
~1d fibers and a lower layer having a lower density than the intermediate layer consisting of fibers with a relatively largest denier number (
a third fiber layer). Further, the liquid conduit is formed from a part of the nonwoven fabric.

(Operations and Effects) In the top sheet configured as described above, bodily fluids excreted onto the top sheet are introduced as raw material into the absorbent core via the liquid conduit. Since the topsheet is a nonwoven fabric, it has a cloth-like feel, but if the first fiber layer in the skin contact area is formed with a low density of fibers with a small denier number, the texture can be made even softer. can.

On the other hand, when the third fiber layer, which is the lower layer, is composed of fibers having a large denier number and has a low density, the fibers can provide cushioning properties to the top sheet. In addition, the fibers act to separate the upper layer of the topsheet from the absorbent core, and also suppress the seepage of body fluids from the absorbent core to the top layer of the topsheet due to capillary action, that is, backflow, so that the topsheet becomes wet with body fluids. The feeling can be reduced. The nonwoven fabric having such low-density first and third layers can increase its strength without impairing the original function of the topsheet by providing a relatively high-density second layer between them. can be improved.

(Example) An example of the present invention will be described below based on the drawings.

FIG. 1 is a perspective view of a sanitary napkin 2 using a top sheet 4 according to the present invention. In the diagram sanitary napkin 2
consists of a top sheet 4, a water-impermeable back sheet 5, and an absorbent core 6 interposed between the two sheets. This napkin 2 is used with the top sheet 4 in contact with a person's skin.

2 and 3 are a partially enlarged perspective view and a sectional view taken along the line 3-3 in FIG. 2 for explaining the top sheet 4. FIG. In the figure, the top sheet 4 has an upper opening 13a and a lower opening 1.
3b, and extends toward the absorbent core 6.
3, and a skin contact area 1 continuous to the periphery of the upper surface opening 13a.
Consists of 2 etc. The top sheet 4 has an upper layer (first fiber layer) forming the outer surface at least in the skin contact area 12.
14, a lower layer (third fiber layer) 16 forming an inner surface, and an intermediate layer (second fiber layer) 15 interposed between both layers. The pipe wall of the liquid conduit 13 shown in the figure is also formed by these first to third fiber layers, or by a part of these layers.

In order to ensure that the surface sheet used for such absorbent articles has sufficient functions and effects, the diameter of the top opening 13a is set to 02 to 5 mm, particularly 0.7 to 3.5 mm. None, the total opening area ratio is 20 to 70%, the inclination α of the tube wall is 10 degrees or more, and the height H of the liquid guide tube 13 is 0.5 to 5 mm. Furthermore, the top sheet 4 is used with the lower surface opening 13b directed toward the inside of the napkin 2, and more preferably in contact with the absorbent core 6.

First to third fiber layers 14, 15, which constitute the topsheet 4.
Reference numeral 16 is made of a nonwoven fabric in which heat-meltable fibers are fused together, and a melt-blown nonwoven fabric described later is suitable as such a nonwoven fabric. Fibers made of thermoplastic synthetic fibers such as olefin-based, polyester-based, polyamide-based, and EVA-based fibers can be used as the heat-meltable fibers. In the first to third fibers 14, 15, and 16, the second fiber layer 15, which is an intermediate layer, is composed of fibers 15a of 0.001 to 0.5 d,
Highest density, preferably 0.05 to 0.9 g/cm
3, which helps maintain the strength of the top sheet 4 as a sheet. The first fiber layer 14, which is the upper layer, is composed of fibers 14a of 0.001 to 0.5 d, and has a lower density than the second fiber layer 15, preferably 0.03 to 0.5 d.
It is in the range of 0.5 g/cm3 and has the effect of keeping the top sheet 4 soft and smooth to the touch. The third fiber layer 16, which is the lower layer, is composed of fibers 16a of 005 to 1d and has a lower density than the second fiber layer 15, preferably 0, 003 to 0. It is in the range of 5 g/cm3. Fiber 16a has a relatively larger denier than fibers 14a and 15a.

With this structure, the relatively bulky fibers 16a among the fibers provide cushioning properties to the topsheet 4, giving the napkin 2 a soft feel when in contact with the skin. The fibers 16a also have the effect of separating the upper layer of the topsheet 4 further away from the absorbent core 3. Therefore, even when the core 4 is in a wet state, the feeling of moisture in the skin contact area 12 in the upper layer of the topsheet 4 can be made slight.

In the above-mentioned first to third fiber layers 14, 15, and 16, the fibers 14a, 15a, and 16a of each layer are intertwined with each other between the layers, or at least one fiber is fused to the other fiber, so that the top sheet 4 is It becomes one piece and maintains its sheet shape. Furthermore, the surface sheet 4 has a basis weight of 10 to 50.
g/rn”, especially between 20 and 40 g/d,
The basis weight of each layer is 2 to 20 g/rn'' for the first fiber layer 14;
Each of the fiber layers 14.
This is preferable in order to obtain the above-mentioned functions required in 15.16.

5 and 6 show each fiber layer 14 in the topsheet 4.
．． 15 and 16 illustrate another aspect of configuring the tube wall of the liquid guide tube 13. FIG. 5 shows that the third fiber layer 16 has a lower opening 1.
Fig. 6 shows the case where the edge of 3b has not been reached.
This shows a case where the fiber layer 14 has not reached the edge of the lower opening 13b. In addition to this example, the end edge of the liquid guide pipe 13 can also be formed of any one fiber layer.

However, in order for the shape of the liquid guide tube 13 to be most stable, it is preferable that this edge includes at least the second fiber layer 15. The various embodiments described above in which each of the fiber layers 14, 15, and 16 constitutes a tube wall can be obtained by variously changing the manufacturing conditions of the melt-blown nonwoven fabric described below.

FIG. 7 is a schematic process diagram for manufacturing the melt-blown nonwoven fabric used for the topsheet 4. The process consists of three extruders 101 each incorporating melt-blown gold (not shown). A conveyor belt 104 having molding elements, a vacuum pipe 108 connecting suction zones 105, 106, 107 provided corresponding to each extruder on the back side of the conveyor belt 104 and extending to a vacuum pump, a conveyor belt drive roll 109, and an auxiliary roll for the same. 110, a pair of nonwoven fabric take-up rolls 111, a nonwoven fabric take-up roll 112, and the like. When raw resin is put into the hopper 115 of each extruder 101, it is melted and extruded, turned into ultrafine fibers in the nozzle section 116 under the action of a high-speed, high-temperature air flow, and deposited on the upper surface of the conveyor belt 104 to form a nonwoven fabric. Suction zone 1 of conveyor belt 104
At points 05, 106, and 107, suction is applied, and the nonwoven fabric is formed into a shape that follows the molded element, that is, a liquid guide pipe 13. Since the nonwoven fabric is formed one layer for each extruder 101, this is referred to as the nonwoven fabric 1 in the figure.
17.118.119. Non-woven fabric 117.1
The fibers 18 and 119 are intertwined with each other or fused to form an integrated sheet, which is wound up by a winding roll 112. In this step, a nonwoven fabric with appropriate properties can be obtained by changing the operating conditions of each extruder 101, such as selecting the melt-blown metal, adjusting the discharge amount, and selecting the resin raw material used. Therefore, in order to obtain the topsheet 4, the process is adjusted so that the nonwoven fabric 118 becomes the second fibrous layer I5, and the nonwoven fabrics 117 and 119 respectively become either the first fibrous layer I4 or the third fibrous layer 16. do it.

The top sheet 4 is used for the napkin 2 by cutting it into appropriate dimensions. The top sheet 4 has the third fiber layer 16 hydrophilized to promote the introduction of bodily fluids excreted onto the surface of the first fiber layer 14 into the inside of the napkin 2, and This can be useful for reducing the wet feeling on the surface of the fiber layer 14.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a sanitary napkin suitable for using the top sheet according to the present invention, and FIG.
Figure 3 is a partially enlarged perspective view of the top sheet in the figure.
3-3 line sectional view in the figure, FIG. 4 is a sectional view showing how the top sheet shown in FIG. 3 is used in a sanitary napkin, and FIGS. , FIG. 7 is a schematic process diagram for manufacturing the top sheet. 4...Top sheet 12...Skin contact area 13...Liquid guide tube 13a...Upper surface opening 13b...Lower surface opening 14...First fiber layer (upper layer) 15...Second Fiber layer (middle layer) 16...Third fiber layer (lower layer) 21st! I kuLn ■ 111 〇 taste trench
Gently squeeze

Claims (1)

[Claims] A top sheet of an absorbent article comprising liquid guide tubes having upper and lower surface openings extending downward and arranged, and a skin contact area continuous to the periphery of the upper surface openings of these liquid guide tubes. is made of a nonwoven fabric to which heat-fusible fibers are fused, and the nonwoven fabric has a surface area of 0.0% at least in the skin contact area.
The densest middle layer (second fiber layer) consisting of fibers of 0.001 to 0.5 d (denier), 0.001 to 0.5 d
An upper layer (first layer) having a lower density than the middle layer made of fibers
and a lower layer (third fiber layer) having a lower density than the intermediate layer made of fibers of 0.05 to 1 d and having a relatively largest denier number, The top sheet of the absorbent article, wherein the liquid guide pipe is formed from a part of the nonwoven fabric.