JP2002205357A - Elastic composite sheet and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an elastic composite sheet having an excellent performance simply and at a high speed. SOLUTION: A belt conveyor 3 being moved, rubber strands 1 having elasticity of 200% or above are oversupplied onto the belt conveyor 3 at a higher speed than the speed of movement of the belt conveyor 3. The supplied rubber strands 1 are thereby disposed helically in continuity on the belt conveyor 3. The rubber strands 1 disposed helically are joined thereafter to a nonwoven fabric having an extension percentage of 100% or above in one direction at least. Thereby the elastic composite sheet showing the elasticity of 200% or above is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic composite sheet having spirally arranged rubber strands bonded to a nonwoven fabric and a method for producing the same. In particular, the present invention provides a continuous stretch of rubber strand formed on a plane by over-supplying a rubber strand on a moving plane and joining the stretch and the extensible non-woven fabric by a simple means. The present invention relates to a composite sheet and a method for producing the composite sheet. This stretch composite sheet is particularly suitable for stretch bandages,
It is used for clothing such as supporters, cuffs of clothing, elastic parts such as diapers, medical and sanitary materials.

[0002]

2. Description of the Related Art As described in JP-A-3-213543 and JP-A-8-174664, various types of stretchable composite sheets formed by laminating a nonwoven fabric and an elastic body have been conventionally used. Technology has been proposed. In the method of manufacturing an elastic body described in JP-A-3-213543, first, a narrow band-like elastic body such as a rubber thread or flat rubber is stretched in a longitudinal direction between a nonwoven fabric on an upper surface and a nonwoven fabric on a lower surface. Supply. Then, the nonwoven fabric on the upper surface and the nonwoven fabric on the lower surface are partially bonded by utilizing the adhesiveness of the nonwoven fabric, and a large number of bonded portions and non-bonded portions are formed on the upper nonwoven fabric. Thereby, an elastic body in which the elastic body in the stretched state is integrated with the nonwoven fabric on the upper surface and the lower surface is manufactured.

[0003] Japanese Patent Application Laid-Open No. 8-174664 discloses a composite in which the direction of expansion and contraction is regulated. The composite is obtained by laminating a stretchable elastomer layer on a stretched long-fiber web. The drawn long-fiber web is obtained by stretching a long-fiber web formed by spinning a thermoplastic resin in one direction, and arranging the fibers of the web in almost one direction.
By forming the composite body in which the direction of expansion and contraction is restricted in this way, a stretchable composite sheet having a good texture and a moderate elasticity can be obtained.

[0004]

However, in recent years, with the development of diapers and other materials for clothing, it has been demanded to produce a stretchable composite sheet with high quality at low cost and high productivity. . For that purpose, it is necessary that the manufacturing process is simple and that the stretchable composite sheet is manufactured at high speed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-performance stretchable composite sheet which can be easily and rapidly manufactured by utilizing a method for manufacturing a reinforcing sheet established with ordinary yarns other than rubber, and a method for manufacturing the same. Is to provide.

[0006]

In order to achieve the above object, a stretchable composite sheet according to the present invention comprises a nonwoven fabric having an elongation of at least 100% in at least one direction, and a spirally continuous nonwoven fabric on the nonwoven fabric. And joined to the nonwoven fabric,
Rubber strands having an elasticity of 200% or more.

[0007] In the above invention, at least 10 directions
Rubber strands having an elasticity of 200% or more are continuously arranged spirally on a nonwoven fabric having an elongation of 0% or more and joined to the nonwoven fabric. Shows a stretchability of 200% or more in a direction having an elongation of 100% or more, and a stretchable composite sheet with good performance is realized. When manufacturing such an elastic composite sheet, for example, as described later, a rubber strand is excessively supplied to a moving surface or a moving nonwoven fabric, or a melt strand extruded from a spinning port. The rubber strands can be spirally arranged on the surface by a simple and high-speed method such as spirally swirling by hot air, and mass production of the elastic composite sheet can be achieved at low cost. In addition, since the rubber strands are spirally arranged, the obtained elastic composite sheet has a small initial tensile tension and a gradual load curve. Furthermore, since the rubber strands are continuously arranged spirally and joined to the nonwoven fabric, the stretchable composite sheet of the present invention may have elasticity in all directions according to the direction in which the nonwoven fabric has elongation. It becomes possible.

The present invention also relates to a method for producing a stretchable composite sheet comprising a non-woven fabric and a rubber strand bonded thereto, wherein the surface for arranging the rubber strand in a helical manner is moved by at least 200%. A process of spirally disposing the rubber strands on the moving surface by over-feeding the rubber strands having a property to the surface at a speed higher than the moving speed of the surface; Joining the arranged rubber strands and a nonwoven fabric having an elongation of at least 100% in at least one direction.

In the above invention, when manufacturing the stretchable composite sheet, first, the surface for arranging the rubber strands, which are the material of the sheet, in a spiral shape is moved.
By over-supplying the rubber strand having the elasticity of 0% or more to the moving surface at a speed higher than the moving speed of the moving surface, the rubber strand is continuously arranged spirally on the moving surface. Next, the elastic composite sheet is manufactured by joining the spirally arranged rubber strands and the nonwoven fabric having an elongation of at least 100% in at least one direction. In such a manufacturing method, the rubber strands can be continuously arranged spirally by a simple and high-speed method of over-supplying the rubber strands to the moving surface. Therefore, it is possible to mass-produce the elastic composite sheet having the above-mentioned characteristics at low cost by the spiral arrangement of the rubber strands.

Further, in the above manufacturing method, the step of over-supplying the rubber strand on the moving surface includes:
In the middle of the supply path of the rubber strand to the surface, the rubber strand is brought into contact with the oscillating reflector plate, and the rubber strand is over-supplied to the surface while being spread on the surface by the oscillation of the reflector plate. May be.

Further, the present invention relates to a method for producing a stretchable composite sheet comprising a nonwoven fabric and a rubber strand bonded thereto, wherein the nonwoven fabric having an elongation of 100% or more is moved in at least one direction and solidified. While spinning a molten strand made of a thermoplastic elastomer melt having an elasticity of 200% or more above the moving nonwoven fabric, the molten strand is oversupplied to the nonwoven fabric at a speed higher than the moving speed of the nonwoven fabric. Thereby, the rubber strand obtained by solidifying the molten strand is continuously arranged spirally on the nonwoven fabric, and the rubber strand and the nonwoven fabric are joined by the heat of fusion of the molten strand.

In the above invention, the nonwoven fabric, which is the material of the stretchable composite sheet, is moved, and the molten strand made of the thermoplastic elastomer melt is spun above the moving nonwoven fabric, and the molten strand is supplied to the nonwoven fabric. I do.
Thereby, the rubber strand obtained by solidifying the molten strand is continuously arranged spirally on the nonwoven fabric, and the rubber strand and the nonwoven fabric are joined by the heat of fusion of the molten strand. According to such a manufacturing method, the step of spirally arranging the rubber strands on the nonwoven fabric and the step of joining the rubber strands to the nonwoven fabric are performed in one step, so that the stretchable composite sheet can be more simply and quickly processed. Is manufactured.

Further, the method for producing a stretchable composite sheet according to the present invention is a method for producing a stretchable composite sheet comprising a nonwoven fabric and rubber strands joined thereto.
% Of a thermoplastic elastomer melt having an elasticity of not less than 10% and spinning a molten strand from a spinning port, and blowing hot air from a plurality of jet ports provided around the spinning port to generate the hot air. Spirally rotating the molten strand, by supplying the molten strand to a moving surface, a step of continuously arranging the rubber strand obtained by solidifying the molten strand in a spiral on the surface, Joining the rubber strands arranged in a spiral and a nonwoven fabric having an elongation of at least 100% in at least one direction.

In the above invention, when producing a stretchable composite sheet, first, a thermoplastic elastomer melt having a stretchability of 200% or more when solidified is extruded from a spinning port to spin a molten strand. Next, hot air is blown out from a plurality of outlets provided around the spinning port, and the hot air is used to supply the molten strand to the moving surface while spirally rotating the spun molten strand. I do. Thereby, the rubber strand obtained by solidifying the molten strand is continuously arranged in a spiral shape on the moving surface.
Thereafter, the elastic composite sheet is manufactured by joining the spirally arranged rubber strands and the nonwoven fabric having an elongation of at least 100% in at least one direction. In such a manufacturing method, a rubber strand is continuously and spirally formed by a simple and high-speed method in which a molten strand spun using a thermoplastic elastomer melt is spirally turned by hot air and supplied to a moving surface. Can be arranged. Therefore, it is possible to mass-produce the elastic composite sheet having the above-mentioned characteristics at low cost by the spiral arrangement of the rubber strands.

Further, the method for producing a stretchable composite sheet according to the present invention is a method for producing a stretchable composite sheet comprising a nonwoven fabric and rubber strands joined thereto, wherein the nonwoven fabric has an elongation of at least 100% in at least one direction. And extruding a thermoplastic elastomer melt having a stretchability of 200% or more when solidified from a spinning port above the nonwoven fabric to spin a molten strand, and a plurality of steps provided around the spinning port. The molten strand is supplied to the moving non-woven fabric while the molten strand is spirally swirled by the hot air by ejecting the hot air from the jet outlet of the hot air, whereby the rubber strand formed by solidification of the molten strand is removed. The rubber strands are continuously arranged spirally on the nonwoven fabric, and the heat of fusion of the melt strands and the rubber strands. And a step of bonding the serial nonwoven.

In the above invention, first, the nonwoven fabric, which is the material of the stretchable composite sheet, is moved, and the thermoplastic elastomer melt is extruded from the spinneret above the nonwoven fabric to spin the rubber strand. Then, by blowing hot air from a plurality of outlets provided around the spinning port, the spun molten strand is spirally swirled by the hot air. By supplying the melted strand to the non-woven fabric while swirling it in this way, the rubber strand formed by solidification of the melted strand is continuously arranged spirally on the non-woven fabric, and the rubber is heated by the melting heat of the melted strand. The strand and the nonwoven are joined. According to such a manufacturing method, the step of spirally arranging the rubber strands on the nonwoven fabric and the step of bonding the rubber strands to the nonwoven fabric are performed in one step. Manufactured.

"Elongation" in the present invention is defined by JIS-L1
095. That is, a web having a width of 5 cm is gripped at an interval of 10 cm in the length direction, and a tensile speed of 30 c
The elongation with respect to the original length when the web is broken is expressed in%.

The "strand" in the present invention includes a relatively thin endless or quasi-endless flexible material usually called a filament, as well as a relatively thick endless or quasi-endless flexible material. . In the case of a filament, the fineness is about several hundred tex even if it is large, but the "strand" in the present invention includes a fineness of several thousand tex. In addition, the "strand" may form a thick strand by gathering individual thin strands.

The term "strand elasticity" used in the present invention means that after a strand is tensioned to give a certain elongation,
When the tension is released, the elongation is elastically restored to the vicinity of the original length by rubber elasticity. The rate at which the strands elastically recover does not need to be completely restored to their original length, but at least 50%, preferably 80% (residual elongation 20%) of the elongation imparted to the strand, more preferably 90
% Or more (residual elongation of 10% or less).

[0020]

Next, embodiments of the present invention will be described with reference to the drawings.

In the present invention, the term “longitudinal direction” used in the description of the manufacturing process of the stretchable composite sheet and the arrangement direction of the fibers of the nonwoven fabric refers to those directions when the stretchable composite sheet or the nonwoven fabric is manufactured. The "transverse direction" means the direction perpendicular to the longitudinal direction, that is, the width direction of the nonwoven fabric or the stretchable composite sheet.

(First Embodiment) FIG. 1 is a perspective view for explaining a method of manufacturing a stretchable composite sheet according to a first embodiment of the present invention. FIG. 1 shows an apparatus for spirally arranging rubber strands constituting a stretchable composite sheet on a plane.

On the upper side of the belt conveyor 3 running in the vertical direction indicated by the arrow A in FIG. 1, a cylindrical shape arranged in the horizontal direction perpendicular to the running direction, that is, the width direction of the belt conveyor 3 is provided. Are arranged in a plurality.
Each thread guide 2 guides the rubber strand 1 supplied from above the belt conveyor 3 to the upper surface of the belt conveyor 3. The rubber strand 1 has an elasticity of 200% or more in its length direction.

The manufacturing apparatus is provided with a driving device for moving the belt conveyor 3 and a yarn supply device (not shown) for supplying the rubber strand 1 onto the belt conveyor 3 through the yarn guide 2. In the present embodiment, the belt conveyor 3 is caused to travel by a driving device such that the belt-shaped belt conveyor 3 moves in a direction parallel to its length direction. The running speed, that is, the moving speed of the belt conveyor 3 is adjusted by a driving device, and the supply speed of the rubber strand 1 is adjusted by a yarn feeding device so that the feeding speed of the rubber strand 1 is higher than the running speed of the belt conveyor 3. As a result, each rubber strand 1 is oversupplied onto the belt conveyor 3.

In the manufacturing apparatus configured as described above, while the belt conveyor 3 is running, the rubber strand 1 is over-supplied at a speed higher than the running speed, so that the over-supplied rubber strand 1 is It is swirled up and continuously arranged in a spiral. As a result, a spiral rubber strand 4 formed by spirally arranging the rubber strands 1 on the upper surface of the belt conveyor 3 is formed on the upper surface of the belt conveyor 3. At that time, the lateral diameter X of the spiral close to a circle or an ellipse shown in FIG. 1 is determined by the material, thickness, and degree of oversupply of the rubber strand 1. The diameter Y in the vertical direction shown in FIG. 1 is determined by the diameter X and the traveling speed of the belt conveyor 3 (moving surface). FIG. 1 shows only a spiral arrangement of two rubber strands for the sake of simplicity, but for industrialization, a stretchable composite sheet is manufactured in a multiple spiral arrangement. As shown in FIG. 1, these adjacent spiral rubber strands 4 are
It is desirable that at least the lateral ends overlap each other.

Next, the spiral rubber strand 4 placed on the belt conveyor 3 is removed by at least 100% in one direction.
The elastic composite sheet is manufactured by joining with the nonwoven fabric having the above elongation. As the non-woven fabric, a non-woven fabric in which fibers are arranged in the length direction (longitudinal direction) can be used. In this case, the non-woven fabric is in the horizontal direction (width direction).
Has an elongation of 100% or more.

At the time of joining the spiral rubber strand 4 and the nonwoven fabric, the nonwoven fabric is laminated on the spiral rubber strand 4 on the belt at the downstream side of the belt conveyor 3 in the running direction, It can be joined by a heating method or an adhesive. Alternatively, the spiral rubber strand 4 on the belt conveyor 3 may be transferred to another member and then joined to the nonwoven fabric. Further, the nonwoven fabric may be supplied onto the belt conveyor 3 on the upstream side of the portion where the rubber strand 1 is supplied, and the rubber strand 1 may be spirally arranged on the nonwoven fabric. In this case, before the rubber strand 1 supplied from the yarn guide 2 reaches the non-woven fabric on the belt conveyor 3, an adhesive is applied to the rubber strand 1 by a spray 5 as shown in FIG. While disposing the strand 1 in a spiral shape, it can be bonded to the nonwoven fabric by an adhesive. Alternatively, after arranging the spiral rubber strands 4 on the nonwoven fabric, they may be joined by a method such as heating.

When the material of the rubber strand 1 is a thermoplastic elastomer, the thermoplastic elastomer can be supplied in a molten state onto the belt conveyor 3, in which case the yarn guide 2 serves as a spinning port. In that case, a thermoplastic elastomer melt having a stretchability of 200% or more when solidified is extruded from a spinning port, whereby a molten strand made of the melt is spun. Alternatively, a latex such as natural rubber can be supplied to form a strand. In these cases,
As described above, the nonwoven fabric and the spiral rubber strand can be joined by placing the nonwoven fabric on the belt conveyor 3 and running them. When the nonwoven fabric is placed on the belt conveyor 3, the rubber strand 1 is joined to the nonwoven fabric by the heat of fusion that has been in the state of the molten strand in the step of spirally arranging the rubber strand 1.

When the rubber strand 1 does not exhibit thermoplasticity or adhesiveness as in the case of molded vulcanized natural rubber, an adhesive latex is supplied to the rubber strand 1 from the spray 5 described above, or separately. It is necessary to supply a hot melt adhesive to assist the adhesiveness of the rubber strand 1.

The produced stretchable composite sheet had a stretchability of 200% or more in the direction in which the nonwoven fabric had an elongation of 100% or more, and a stretchable composite sheet with good performance was obtained. When manufacturing such an elastic composite sheet, the rubber strand is spirally wound on the surface by a simple method such as over-feeding the rubber strand to a moving surface such as the surface of a belt conveyor or a moving nonwoven fabric as described above. The elastic composite sheets can be mass-produced at a low cost and can be mass-produced.

FIG. 2 is a perspective view showing an example in which a reflecting plate is used in the process of over-supply of the rubber strand in the manufacturing apparatus shown in FIG.

In the manufacturing apparatus shown in FIG. 2, one end of the reflection plate 6 is disposed immediately below each yarn guide 2, that is, between the yarn guide 2 and the belt conveyor 3 in the supply path of the rubber strand 1. ing. Each reflection plate 6 is obliquely inclined with respect to the surface of the belt conveyor 3, and extends obliquely downward from a portion immediately below the yarn guide 2. This manufacturing apparatus is provided with an unillustrated swing drive device that swings each of the reflectors 6 so that the reflectors 6 rotate in both directions about the extension of the central axis of the yarn guide 2 substantially as a rotation center. ing. The swinging drive device swings the reflector 6 while the reflector 6 is always inclined with respect to the surface of the belt conveyor 3. The reflection plate 6 may be attached to the yarn guide 2, and the reflection plate 6 may be swung together with the yarn guide 2.

In the manufacturing apparatus shown in FIG. 2, the strand 1 oversupplied to the yarn guide 2 is fed onto the reflecting plate 6, and the rubber strand 1 placed on the reflecting plate 6 is brought into contact with the reflecting plate 6. It moves down along its surface. On this occasion,
The rubber strand 1 swings together with the reflector 6 by the swing of the reflector 6, and the rubber strands 6 separated from the reflector 6 are then spread over the belt conveyor 3 by the swing and spirally. It falls while turning like a circle. Thereby, the spiral rubber strand 7 constituted by the rubber strand 1 overlapping on the belt conveyor 3 is formed on the belt conveyor 3.

(Second Embodiment) FIG. 3 is a view for explaining a method of manufacturing a stretchable composite sheet according to a second embodiment of the present invention. FIG. 3A shows a lower surface of a spiral gun arranged on a belt conveyor, and FIG.
(B) shows a part of an apparatus for manufacturing a stretchable composite sheet, in which a spiral gun has a cross section.

A spiral gun 8 is provided above a belt conveyor 17 running in the vertical direction indicated by an arrow B in FIG.
Is arranged. The lower surface of the spiral gun 8 is substantially parallel to the surface of the belt conveyor 17, and the lower surface thereof has a substantially circular spinneret 9 as shown in FIGS. 3 (a) and 3 (b). Are formed, and a plurality of small hot-air ports 10 located around the ring-shaped hot-air cylindrical port 11. From the spinning port 9, a thermoplastic elastomer 18, which is a material of a rubber strand, is extruded in a molten state, and hot air is blown out from the small hot air port 10 and the hot air cylindrical port 11. The hot-air cylindrical port 11 is concentric with the spinning port 9, and the plurality of small hot-air ports 10 are arranged on the circumference concentric with the spinning port 9 at equal intervals in the circumferential direction. Each hot air outlet 10 is obliquely opened with respect to the lower surface of the spiral gun 8 so that the thermoplastic elastomer 18 extruded from the spinneret 9 is spirally swirled by the hot air jetted from the hot air outlet 10. Have been. When the thermoplastic elastomer 18 is solidified in a strand-like form from a molten state, it becomes 2 mm in the length direction of the strand.
What has elasticity of 00% or more is used.

Further, inside the spiral gun 8, a room 8 a is formed around the liquid flow path so as to surround a part of the liquid flow path communicating with the spinning port 9. The lower part of this room 8a is a hot air cylindrical port 11 and a plurality of hot air ports 1
Communicates with 0. A hot air inlet 12 formed on the upper surface of the spiral gun 8 communicates with the upper end of the room 8a via a flow path. Further, a flow straightening plate 13 having a large number of small holes 13a is provided in the room 8a.
The current plate 13 allows the room 8 a
The flow of the hot air introduced into the inside is adjusted, and the hot air is almost uniformly sent into the hot air cylindrical port 11 and each of the hot air small ports 10. In the spiral gun 8 having such a configuration,
Hot air is supplied into the room 8a through the hot air inlet 12;
The hot air passes through the small hole 13a of the current plate 13 and the hot air cylindrical port 1
1 and each of the hot air outlets 10.

In this embodiment, the belt conveyor 17 is
A member for continuously disposing the strands in a spiral shape, and a member for placing the band-shaped nonwoven fabric 15 and moving it. The nonwoven fabric 15 has at least one direction
It has an elongation of 0% or more. As such a nonwoven fabric 15, as in the first embodiment, the length direction (vertical direction)
In this case, the nonwoven fabric 15 has a width of 100 in the lateral direction (width direction).
% Of elongation.

Next, the operation of the manufacturing apparatus shown in FIG. 3 will be described.

The thermoplastic elastomer 18 extruded as a melt from the spinning port 9 turns into a molten strand 14 that spirally turns and falls by the hot air from the small hot air port 10 and the hot air cylindrical port 11. Spun molten strand 14
Is the spiral rubber strand 1
6 and accumulates on the upper surface of the nonwoven fabric 15 that moves as the belt conveyor 17 travels. The accumulated spiral rubber strands 16 are joined to the nonwoven fabric 15 by the heat of fusion that has been obtained from the state of the molten strands 14. By such a process, the spiral rubber strand 16
Are joined to produce a stretchable composite sheet.

In the manufacturing method of the stretchable composite sheet of the present embodiment, the spiral rubber strand 16 is formed on the belt conveyor 17 without supplying the nonwoven fabric 15 on the belt conveyor 17 as in the first embodiment. After that, the spiral rubber strand 16 may be joined to the nonwoven fabric 15.

As in the first embodiment, the manufactured stretchable composite sheet has 200% or more stretchability in the direction in which the nonwoven fabric has 100% or more elongation, and has good performance. The composite sheet was obtained. Also, according to the method for manufacturing the stretchable composite sheet of the present embodiment, the rubber strands are spirally arranged at high speed in a simple manner such that the strands of the melt extruded from the spinning port are spirally turned by hot air. Thus, the elastic composite sheet can be mass-produced at low cost.

Next, the materials used in the stretchable composite sheet of the present invention and the method for producing the same, the features of the method for producing the stretchable composite sheet of the present invention, and the preferred embodiments of the method for producing the same will be described in detail.

The use of rubber strands in the stretchable composite sheet of the present invention and the method for producing the same allows the efficient use of existing rubber strands produced for the purpose of rubber elasticity, elongation, durability and the like. On the point. In other words, compared to the case of using rubber elastic nets, nonwoven fabrics, films, etc., there is no morphological defect that the intersections become thicker, and strands formed from natural rubber latex, which is difficult to mold, are also used. This is because there is a wide range of choices of material, such as possible. Also, because of these, the desired weighted expansion curve, hysteresis curve, and the like can be realized.

As the types of rubber strands constituting the stretchable composite sheet, those obtained by forming natural rubber, synthetic rubber, or thermoplastic elastomer into strands are used.
As such strands, not only round cross-sections but also various shapes such as rectangular tapes are used, and the strands may be composed of monofilaments, and multifilaments which are aggregates of filaments It may be. In addition, not only the strands manufactured in a step different from the step of bonding the rubber strands onto the nonwoven fabric, but also in the step of manufacturing the elastic composite sheet, the strands are spun immediately before the bonding step, and subsequently the rubber strands are spun. Can be shortened by bonding to the nonwoven fabric.

In the present invention, the use of a strand-shaped product has the advantage that a strand formed by vulcanization or the like so that rubber elasticity is most easily exerted can be used. In addition, rubber elastic bodies generally have poor moldability, and in particular, rubber elastic bodies having such elasticity, such as diaper elastic materials that can repeatedly undergo large expansion and contraction of 200% or more, have poor moldability. Therefore, it is most suitable to employ the simplest molding method, that is, strand molding.

The "strand" in the present invention includes a relatively thick endless or quasi-endless material in addition to a relatively thin endless flexible material usually called a filament. When we say filament,
Although it is about several hundred tex when it is large, the strand in the present invention includes one having several thousand tex.

As the rubber strand used in the present invention, a strand having a rubber elasticity of 200% or more is used. However, it is not required that the residual strain when the rubber strand recovers after expanding and contracting by 200% is zero, and it can be used even if it has several tens% of residual strain.

In the present invention, a thermoplastic elastomer is particularly suitable as the material of the rubber strand. The thermoplastic elastomer can bond the rubber strand and the nonwoven fabric only by heat, and the process is simplified, so that the elastic composite sheet can be manufactured at a significantly lower cost.

As the thermoplastic elastomer used in the present invention, polyolefin, synthetic rubber, polyester, polyamide and polyurethane elastomers are used. Of these, synthetic rubbers and polyurethanes in which styrene and olefin are copolymerized expand and contract at a high magnification and have a small stress during expansion and contraction, and are therefore most suitable as rubber strand elastomers used in the present invention. Note that, among the rubber strands, natural rubber strands and vulcanized synthetic rubber strands, which are difficult to join by heat or the like, are bonded to the nonwoven fabric with a latex such as synthetic rubber or natural rubber.

The fiber constituting the nonwoven fabric as the material of the stretchable composite sheet means a fiber in a broad sense meaning both short fibers (short fibers) and continuous filaments. The fibers may be made of ordinary fibers for synthetic fibers such as polypropylene, polyamide and polyester, or may be made of fibers of natural fibers such as cotton and silk, and may be fibers of semi-synthetic fibers such as rayon and acetate. Good.

The nonwoven fabric used as the material of the stretchable composite sheet is as follows:
It is necessary to have at least 100% elongation in a certain direction. As an example of such a nonwoven fabric having an elongation of 100% or more, there is a nonwoven fabric in which fibers are arranged in one direction, and the elongation of the nonwoven fabric in a direction perpendicular to the arrangement direction is 100%.
(See Japanese Patent Application Laid-Open No. 8-174766,
0-34242).

In the present invention, the elongation of 100% or more of the nonwoven fabric is perpendicular to the direction in which the fibers are arranged.
In the fiber arrangement direction, the elongation is several percent to several tens percent, and the elongation stress is large. In this direction, a stretchable composite sheet having dimensional stability can be obtained.

As the nonwoven fabric for the stretchable composite sheet, a spunbonded nonwoven fabric or a melt-blown nonwoven fabric, or a vertically stretched nonwoven fabric of the present invention by the present inventors (Japanese Patent Publication No. 3-36948, JP-A-10-204767).
Non-woven fabrics composed of long fiber filaments, such as the nonwoven fabric described in detail in Japanese Patent Application Laid-Open Publication No. H10-260, or a nonwoven fabric in which tows are opened and arranged in one direction, are used. These long-filament filaments do not fall out of the fibers even after repeated expansion and contraction of several hundred times, and are suitable for so-called lint-free applications. Further, since the stretched nonwoven fabric has strength and dimensional stability in the stretching direction, and since the stretched nonwoven fabric is a glossy nonwoven fabric, the properties of this stretching can also be used in clothing and the like.

In the present invention, the nonwoven fabric for a stretchable composite sheet is described as a nonwoven fabric stretched in one direction.
Even in the nonwoven fabric stretched in the direction, the nonwoven fabric stretched in the longitudinal direction (one direction) of the present invention includes the nonwoven fabric in which the vertical and horizontal balance is lost by increasing the stretching ratio in the vertical direction.

Further, as the nonwoven fabric of the stretchable composite sheet of the present invention, a nonwoven fabric in which short fibers are arranged in one direction is also suitable. The non-woven fabric made of short fibers has a cotton-like texture,
It has a good feel and is preferred for applications that directly touch the skin. As a nonwoven fabric in which fibers made of short fibers are arranged, there is a card-lifted web or the like.

As another example of the nonwoven fabric having an elongation of 100% or more, a spunbonded nonwoven fabric or an ordinary short-fiber nonwoven fabric may be subjected to flexible processing, shrinking processing, or folding and pleating. It may be processed to have an elongation in the lateral direction by performing processing or the like.

The softening means not only softening in a narrow sense in which a softening agent is applied to a nonwoven fabric, but also softening and elongation by physical means such as embossing or shrink-proofing or embossing which are not visually observed. Processing to make a large nonwoven fabric is also included.

The shrinking process is a process for physically or chemically shrinking a cloth, and includes a process called a shrinking process in which fibers are entangled with each other. The shrinking process is partially common to the above-described softening process. As a method of physically shrinking the cloth in the vertical or horizontal direction, for example, there is a method disclosed in JP-A-6-57620.

The pleating process includes a folding process, a pleating process, and the like, and a process of providing a large number of small or irregular wrinkles or folds on a cloth to impart extensibility to the cloth. As an example of increasing the elongation in the vertical direction by forming a fold in the horizontal direction, sun holing (US Pat. No. 2,324,245)
No. 5) and a wide stuffing box (Japanese
No. 4,174,742), a process utilizing a method of producing crepe paper in the papermaking industry, a process of forming a pleat in the longitudinal direction by combining two rollers having a large number of grooves in the axial direction, and the like. Is mentioned. In addition, by devising the emboss pattern, a nonwoven fabric having elasticity in the vertical or horizontal direction can be obtained. Regardless of the type of processing, any occurrence of folds is included in the pleating processing referred to in this specification.

The nonwoven fabric for a stretchable composite sheet of the present invention comprises:
At least 100% in one direction, preferably 200%
The above elongation is required. Non-woven fabric elongation in one direction is 10
From the experimental results, it was confirmed that if the content is 0% or more, the composite sheet with the elastomer exhibits a repetitive elasticity of 200% or more. Elongation conforms to JIS-L1085, width 5
The elongation at break of the nonwoven fabric is determined by setting the gripping interval at 10 cm and the pulling speed at 30 cm per minute in cm.

In the method for producing a stretchable composite sheet of the present invention, rubber strands are continuously formed spirally on a belt conveyor or a nonwoven fabric running in the longitudinal direction.
The spiral shape here is a shape in which a rubber strand turns in a shape close to a circle or an ellipse, and is similar to a shape in which a spiral staircase is projected obliquely onto a plane.

The fact that the rubber strand has a spiral arrangement on the nonwoven fabric is not only characterized in that the strand is formed on the nonwoven fabric by simple means, but also the resulting stretchable composite sheet has a nonwoven fabric having an elongation degree. There is also a feature that it has elasticity in all directions depending on the direction in which it has. Further, in the stretchable composite sheet, since the strand has a shape close to a circle, there is an advantage that the initial tensile tension is small and a gradual load / elongation curve is obtained.

In the connected row of spiral rubber strands in the present invention, it is desirable that the strands be connected so that the row extends in the vertical direction (the flow direction of the production line). The reason that the strands are connected in the vertical direction is that the productivity of the spiral strands is good.
In addition, when the elastic composite sheet is provided with elasticity in the vertical direction, the rubber strands can be effectively used by connecting the rubber strands in the vertical direction.

In such a spiral of the rubber strands connected in the vertical direction, it is desirable that the rows of the spiral rubber strands overlap in the horizontal direction. With this configuration, the manufactured stretchable composite sheet can be used as a stretchable sheet that is continuous in the horizontal direction without a break, and can be a stretchable composite sheet that is stretchable in the horizontal direction.

In the method for producing a stretchable composite sheet of the present invention, the rubber strand is continuously supplied in a spiral manner on the moving surface by over-feeding the rubber strand to the moving surface. The term “oversupply” as used herein means that the rubber strand is supplied to the moving surface at a speed higher than the speed of the moving surface, that is, the moving speed of the belt conveyor. If the feed speed of the rubber strand and the speed of the moving surface are the same, only the rubber strand is linearly arranged on the moving surface. Therefore, when the rubber strand is over-supplied, the rubber strand is supplied at a speed of at least 5 times, preferably at least 20 times, more preferably at least 50 times the speed of the moving surface in the line direction. Supply.

In the present invention, the simplest example of a method of spirally arranging rubber strands on a surface by oversupply is to move a plane in a direction parallel to the plane, and hang the rubber strand on the plane. There are ways to go. If the plane is not moving and the strands are hung on that plane, the strands spiral and accumulate on the plane, but the plane is the upper surface of the conveyor and the conveyor is If the strands move in the direction, the strands are spirally arranged on the conveyor without being collected at one place. That is, the spiral strand is formed by over-supplying the strand to the moving surface. In this case, if the supplied strand is a melt of a thermoplastic elastomer, the rubber strand manufacturing step and the bonding step between the rubber strand and the nonwoven fabric can be performed in one step. Furthermore, in the process, the strands of the thermoplastic elastomer in the molten state are integrated with the non-woven fabric by the heat of fusion of the strands, so that a special heating device for bonding the rubber strands to the non-woven fabric is not required, and the process is very simple. A reasonable method of manufacturing a stretchable composite sheet is realized.

As another example of spirally disposing the rubber strands on the surface, as described with reference to FIG. 2, in the manufacturing apparatus for over-supplying the rubber strands, just below the yarn guide 2, that is, the rubber strands There is a method in which a swinging reflector is provided in the middle of the supply path, and the rubber strand is supplied to the moving surface while being spread by the reflector. It is effective not only to move the reflection plate back and forth and right and left, but also to apply vibration to the reflection plate with a vibrator or the like. Such a method is particularly suitable when it is desired to increase the diameter of the spiral of the rubber strand close to a circle or an ellipse. It is desirable that the reflection plate has been subjected to a process that facilitates separation of the rubber strand therefrom, that is, a so-called release process.

In the method for producing a stretchable composite sheet of the present invention, as another example of disposing the strands spirally on a surface, there is a method using a spiral gun used for a hot melt adhesive or the like. This is used as a simple method to evenly distribute the hot melt adhesive on a flat surface. The spiral gun extrudes the melt as a molten strand from a spinning port, and swirls the molten strand by hot air from a hot air jet provided around the spinning port. Then, the swirling molten strand rests on the moving surface, so that the rubber strands are continuously arranged spirally on the moving surface.

In the method for producing a stretchable composite sheet according to the present invention, a thermoplastic elastomer is melted and supplied to the inside of a spiral gun, and a spiral or spiral rubber strand is formed on a moving surface using the spiral gun. By doing so, the object of the present invention can be achieved. In addition, if the nonwoven fabric is running below the spiral gun, the rubber strand and the nonwoven fabric can be joined in the step of arranging the rubber strands in a spiral. That is, this spiral gun is also a very simple device, and can spin a strand at high speed, and has high productivity. Therefore, the method of producing a stretchable composite sheet while spinning rubber strands using a spiral gun also well matches the purpose of the present invention for producing a high-quality stretchable composite sheet simply and at high speed.

In the manufacturing method of the present invention, the member on the surface which moves to continuously arrange the rubber strands in a spiral manner is typically represented by a belt conveyor, but a rotating cylinder, a roller, etc. Any material can be used as long as the surface moves.
In this case, the moving surface does not necessarily have to be a flat surface, but may be a curved surface or the like. It is desirable that these moving surfaces have been subjected to a mold release treatment for the rubber strands. This is because the moving surface is often stained with an elastomer or an adhesive.

Further, the nonwoven fabric is placed on the moving surface for arranging the rubber strand in a spiral shape and the nonwoven fabric is run, so that the rubber strand and the nonwoven fabric are joined on the moving surface or the rubber strand adheres to the nonwoven fabric. May go. Thereby, the manufacturing process can be shortened, and the manufacturing apparatus can be simplified.

The method for producing a stretchable composite sheet of the present invention comprises:
The usual means of spirally arranging yarns on a surface is 200%
The elastic composite is adapted to the rubber strand having the above elasticity, and further, the rubber strand arranged in a spiral is joined to a nonwoven fabric having an elongation (extensibility) of 100% or more in at least one direction, so that the elastic composite is obtained. The feature is that the sheet can be manufactured.

After the rubber strands are spirally arranged, the rubber strands can be joined to the nonwoven fabric, but the strands are made of a thermoplastic elastomer,
In particular, when the elastomer is supplied as a strand of a molten material (molten strand), it is often rational to supply the nonwoven fabric to the moving surface and to bond the strand to the nonwoven fabric by the heat of fusion of the molten strand. .

When the material of the rubber strand is natural rubber or the like,
When it does not have thermoplasticity, after the adhesive latex or hot melt adhesive is supplied to the rubber strand, the strand is bonded to the nonwoven fabric by the supplied adhesive.

When the strands and the nonwoven fabric are joined spirally on the nonwoven fabric, the strands can be joined with a light degree of adhesion, and then completely joined in another step. In some cases, physical bonding such as needle punching or water jet is used for this bonding.

[0076]

As described above, according to the present invention, a nonwoven fabric having an elongation of 100% or more in at least one direction is formed on a nonwoven fabric.
Since the rubber strands having elasticity of 00% or more are continuously arranged in a spiral shape and joined to the nonwoven fabric, the obtained elastic composite sheet has a nonwoven fabric having an elongation of 100% or more. A stretchable composite sheet having 200% or more stretchability in the direction and having good performance is realized. When manufacturing such an elastic composite sheet, the rubber strands can be spirally arranged on the nonwoven fabric by a simple and high-speed method, so that it is possible to mass-produce the elastic composite sheet at a low cost. It becomes possible. In addition, since the rubber strands are spirally arranged, the obtained elastic composite sheet has an effect that the initial tensile tension is small and a round weighting curve is obtained. Furthermore, since the rubber strands are spirally arranged and joined to the nonwoven fabric, the stretchable composite sheet of the present invention can have elasticity in all directions according to the direction in which the nonwoven fabric has elongation. effective.

According to the method for producing a stretchable composite sheet of the present invention, rubber strands are excessively supplied to a moving surface or a moving nonwoven fabric, or a melt strand extruded from a spinning port is heated with hot air. Since the rubber strands can be continuously arranged in a spiral manner in a simple and high-speed manner, such as spirally turning, the above-described stretchable composite sheet can be mass-produced at low cost. .

The elastic composite sheet of the present invention can be used for elastic bandages, supporters, cuffs of clothing, elastic tape, stretch belts, bra straps, belly bands, pregnant women's belts, gloves and socks, and diapers and incontinence pads. It is suitably used for clothing such as stretchable elastic portions of sanitary materials such as sanitary materials, medical treatment and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a method for manufacturing a stretchable composite sheet according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an example in which a reflecting plate is used in the process of over-supplying rubber strands in the manufacturing apparatus shown in FIG.

FIG. 3 is a view for explaining a method for producing a stretchable composite sheet according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber strand 2 Thread guide 3, 17 Belt conveyor 4, 7, 16 Spiral rubber strand 5 Spray 6 Reflector 8 Spiral gun 8a Room 9 Spinneret 10 Hot air outlet 11 Hot air cylindrical opening 12 Hot air inlet 13 Rectifying plate 14 Melting Strand 15 non-woven fabric 18 thermoplastic elastomer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D04H 3/16 D04H 3/16 (72) Inventor Shuichi Murakami 4-33-5 Itabashi, Itabashi-ku, Tokyo (72) ) Inventor Dai Ishida 584-1 Towada, Narita-shi, Chiba F-term (reference) 4F100 AN00B BA02 DG04B DG15A EH902 GB71 GB72 JK06 JK08 JK08B YY00B 4L047 BA08 BB08 BD04 CB10 EA22

Claims (6)

[Claims] 1. A nonwoven fabric having an elongation of at least 100% in at least one direction, and a rubber strand having a stretchability of 200% or more, which is continuously arranged spirally on the nonwoven fabric and joined to the nonwoven fabric. And a stretchable composite sheet having: 2. A method for producing a stretchable composite sheet comprising a nonwoven fabric and a rubber strand bonded thereto, wherein the rubber has a stretchability of 200% or more while moving a surface for arranging the rubber strand spirally. Over-feeding the strands to the surface at a speed higher than the moving speed of the surface to continuously arrange the rubber strands on the moving surface in a spiral manner; and Joining a rubber strand and a nonwoven fabric having an elongation of at least 100% in at least one direction. 3. In the step of over-supplying the rubber strand onto the moving surface, the rubber strand is brought into contact with an oscillating reflector in the middle of a supply path of the rubber strand to the surface, Overfeeding the surface while spreading the strand on the surface by swinging the reflector,
A method for producing a stretchable composite sheet according to claim 2. 4. A method for producing a stretchable composite sheet comprising a nonwoven fabric and a rubber strand joined thereto, wherein the nonwoven fabric having an elongation of 100% or more is moved in at least one direction and 200% or more when solidified. While spinning a molten strand made of a thermoplastic elastomer melt having elasticity, above the moving nonwoven fabric,
By over-feeding the molten strand to the nonwoven fabric at a speed higher than the moving speed of the nonwoven fabric, the rubber strand obtained by solidifying the molten strand is continuously arranged spirally on the nonwoven fabric, and the A method for producing an elastic composite sheet, wherein the rubber strand and the nonwoven fabric are joined by the heat of fusion of the molten strand. 5. A method for producing a stretchable composite sheet comprising a nonwoven fabric and a rubber strand joined thereto, comprising: extruding a thermoplastic elastomer melt having a stretchability of 200% or more when solidified from a spinning port to form a molten strand. Spinning, and supplying the molten strand to a moving surface while spirally turning the molten strand by the hot air by ejecting hot air from a plurality of ejection ports provided around the spinning port. A step of continuously arranging the rubber strands obtained by solidifying the molten strands on the surface in a spiral manner; and the elongation of the rubber strands spirally arranged in at least one direction by 100% or more. Bonding a non-woven fabric having the following. 6. A method for producing a stretchable composite sheet comprising a nonwoven fabric and a rubber strand joined thereto, wherein the nonwoven fabric having an elongation of 100% or more is moved in at least one direction and 200% or more when solidified. Extruding a thermoplastic elastomer melt having elasticity from a spinning port above the nonwoven fabric to spin a molten strand; and blowing hot air from a plurality of jet ports provided around the spinning port to produce the hot air. By spirally rotating the molten strand by supplying the molten strand to the moving nonwoven fabric, the rubber strand obtained by solidifying the molten strand is continuously arranged spirally on the nonwoven fabric, And bonding the rubber strand and the nonwoven fabric with the heat of fusion of the molten strand. The method of producing a composite sheet.