JPH01148857A - Nonwoven fabric and apparatus for producing the same - Google Patents

Abstract

PURPOSE: To obtain a non-woven fabric having excellent peeling-resistant strength and excellent durability by arranging many yarns as warps and wefts in parallel and in a crossed state and then heating and pressing the yarns to join the warps to the wefts, wherein each of the yarns comprises a base layer comprising a synthetic resin having a high melting point and surface layers comprising a synthetic resin having a low melting point. CONSTITUTION: Yarns 1 and 2, such as flat yarns, each having a composite layer structure comprising a synthetic resin A having a high melting point as a base material and a synthetic resin A having a low melting point as surface layers, are arranged as warps and wefts in at least two crossed layers. The overlapped and carried warps and wefts 1 and 2 are heated and pressed at a temperature which is higher than the melting point of the resin B used for the surface layers but lower than the melting point of the resin A used for the base material, thus integrally joining the yarns as the warps and the wefts to each other at their crossed points.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nonwoven fabric mainly in the form of a net, which is made by arranging a large number of threads in a warp-to-warp direction and intersecting them and bonding them to each other at the intersections, and an apparatus for producing the same. It is related to.

[Prior art and its problems] This net-like nonwoven fabric can be used, for example, as a reinforcing layer for paper, synthetic resin films, fiber laminates, and other sheet materials, as well as for backing reinforcing layers for floor tiles and other construction materials. reinforcement material,
It is widely used in screens and other various fields.

Conventional nonwoven fabrics of this type are disclosed in, for example, Japanese Patent Application Laid-open No. 58-1042.
As shown in Publication No. 55, yarns such as ordinary multifilament yarns are used for the warp and weft, and a large number of each are arranged in parallel and intersected in at least two layers, and the warp layer and weft layer are intersected. It is common that these are bonded together at the intersections of the threads with an adhesive such as an adhesive resin.

However, in manufacturing the non-woven fabric, as shown in the above-mentioned publication, the weft, which is fed in a meandering manner around a pair of yarn support members, is dipped in an adhesive, and then the warp is aligned with the weft. The method involves heating and drying, or after aligning the weft and warp yarns, immersing them in an adhesive and heating and drying them. After this dipping step, the weft yarns are separated from the yarn support member, so there is no slack, distortion, or There is a problem in that the eyes become crooked. Even when both the weft and weft yarns that have separated from the yarn support device are held by belts from above and below, the above-mentioned slack cannot be avoided.

In addition, the nonwoven fabric produced as described above has disadvantages in that the threads are not sufficiently bonded to each other by the adhesive, and peeling easily occurs. Moreover, as mentioned above, in the past, only multifilament yarns were used for the weft and warp threads, and the scope of their use was limited.

Therefore, the applicant uses monofilament yarn made of thermoplastic synthetic resin or flat yarn, i.e., tape-like yarn, as the warp yarn and heat-presses it to efficiently and reliably fuse the warp yarn. However, in this case, if the yarn is made of only one type of synthetic resin, the stretching effect and strength may decrease due to softening and melting during heat-pressing, or shrinkage may occur. There is a risk that the eyes will collapse due to deformation.

The present invention was made in view of the above, and by using mainly drawn tape-like yarns or monofilant yarns that have a special composite layer structure for the warp and warp yarns, the warp and warp yarns are bonded by thermocompression. The object of the present invention is to provide a net-like nonwoven fabric that can reliably and firmly bond the threads together, has sufficient strength in its filaments, and has excellent peeling resistance and durability. To provide an apparatus that can reliably and efficiently produce products without collapsing.

[Means for Solving the Problems] The nonwoven fabric of the present invention which solves the above problems is made of two or more types of synthetic resins having different melting points, in which the synthetic resin with the higher melting point is used as the base material, and the nonwoven fabric with the higher melting point is used as the base material. A large number of yarns having a composite layer structure with a surface layer made of a low-temperature synthetic resin are arranged in parallel in each direction and intersected in at least two layers, and the temperature range is above the melting point of the surface layer resin and below the melting point of the base resin. It is characterized by being bonded under heat and pressure, and the threads of the weft and warp are joined and integrated at their intersections.

In addition, in the manufacturing apparatus of the present invention for manufacturing the above-mentioned nonwoven fabric, a pair of yarn support members are arranged in parallel on both sides with an interval, and the yarns stretched between them are supported substantially in parallel. A thread with a composite layer structure consisting of a thread supporting member that is continuously fed and two or more types of synthetic resins with different melting points, of which the synthetic resin with the higher melting point is the base material and the synthetic resin with the lower melting point is the surface layer. a device that continuously supplies a weft as a weft and extends it in a meandering manner between the pair of yarn support members;
A device that continuously supplies the threads of the composite layer structure as warp threads and overlaps them in a direction perpendicular to the weft threads; A water device that heats the base resin to a temperature below the melting point, and a crimping device that crimps both the warp and weft yarns from above and below under the heating state and joins them at the intersection points, and the pair of yarn support members are connected to the heating device. and extending to the position of the crimping device.

[Function] According to the nonwoven fabric of the present invention having the above-mentioned configuration, the surface layers of the weft and warp threads made of a synthetic resin having a lower melting point than the base resin soften and melt together, and the threads reliably and melt at the intersections between the threads. It is strongly bonded and integrated and will not peel off easily.

Moreover, since the thermocompression bonding is carried out in a temperature range above the melting point of the surface layer resin and below the melting point of the base resin, even if the surface layer softens and melts, the base material does not soften and melt, and the base resin Properties such as tensile strength are not impaired, and the original strength is maintained as is, and the strength necessary for use as this type of nonwoven fabric can be sufficiently maintained.

In addition, in the production of nonwoven fabric using the production apparatus of the present invention having the above configuration, threads with a special composite layer structure in which the surface layer is made of a resin having a lower melting point than the base material resin are used for the warp and weft, and as the weft. The yarn is fed by passing it around a pair of yarn support members in a meandering manner approximately parallel to each other, and after aligning the yarn that will become the warp on the upper and/or lower surfaces of the weft in the intersecting direction, the warp and weft yarns are is heated to a temperature higher than the melting point of the surface layer resin of the yarn and lower than the melting point of the base resin to soften and melt only the surface layer resin, and under this heated state, the yarns are pressed together from above and below. They can be reliably bonded at the intersection points, and the above-mentioned nonwoven fabric can be efficiently produced without affecting the properties of the base resin of the yarn.

In particular, since the pair of yarn support members that support and feed the yarns that will become the wefts extend to the position of the heating device and the crimping device, the wefts may become slack or distorted during this feeding process. Therefore, combined with the fact that the bonding can be performed simply by heat-pressing, it is possible to manufacture a nonwoven fabric without causing any loss of stitches or the like.

[Example] Next, embodiments of the present invention will be described based on the drawings.

Figures 1 and 2 show yarn (1) with a composite layer structure of warp and warp.
As (2), two types of synthetic resins (A) with different melting points (
An example of the nonwoven fabric of the present invention manufactured using the tape-like yarn consisting of B) is shown. The tape-shaped thread is a multilayer film formed by laminating a synthetic resin (B) with a lower melting point as a surface layer on one or both sides of a base material layer made of a synthetic resin (A) with a relatively high melting point. The multilayer film is usually uniaxially stretched before slitting, or uniaxially stretched after slitting, and in the present invention, the thickness is, for example, several microns. A diameter of several hundred microns is preferably used.

3 and 4 show an apparatus for producing a nonwoven fabric as shown in FIG. 1, and has the following configuration.

A pair of yarn support members (10a) and (10b) are provided, which are arranged side by side on both the left and right sides at intervals and extend in the yarn feeding direction. The thread support member (10a) (fob) has substantially the same structure, has a spiral screw, helical spring, or other similar spiral guide structure in the main part of its entire length, and is suspended between the two. The threads, which will become the weft threads, are supported substantially in parallel and can be fed continuously by rotating the support member (10a) (fob). In particular, in the apparatus of the present invention, both yarn supporting members (10a) and (10b) are provided extending to the positions of the heating device and the crimping device, which will be described later.

(20) The yarn (1) having a composite layer structure made of the above-mentioned multilayer tape-like yarn or the like supplied from a bobbin or the like is continuously supplied as a weft to the pair of yarn supporting members (10a) (
10b) A hollow guide arm extending in the radial direction from a hollow shaft portion (21) located approximately at the center between the thread supporting members (10a) and (10b) on both sides. (22), and the hollow shaft portion (21
) is provided so as to be rotated by an appropriate drive means. Therefore, the weft yarn is attached to the hollow shaft portion (21
) to the outside through the tip opening of the guide arm (22), and the thread support devices (LOa) on both sides (10b
) and is fed by being wound in a meandering manner at the required intervals.

Although the illustrated device has one guide arm (22), it is possible to increase the number of guide arms (22), thereby making it possible to supply a plurality of weft yarns.

(30) is a guide roller (3) from above and below the device.
1) The yarn (2) that is continuously supplied through (31) is used as a warp, and is intersected with the yarn (1) that is a weft that is passed over the yarn support members (10a) and (10b). It is also a device for overlapping in the direction, consisting of a pair of grooved rolls (32) for warping (32), whereby the warp yarns can be made parallel and arranged at a required interval and overlapped with the weft yarns. It looks like this.

(40) is a heating device such as a heater that heats both warp and weft yarns (1) and (2) which are overlapped and sent as described above;
Composite layer structure yarn (1) particularly used in the present invention
(2) above the melting point of the surface layer resin (B) and the base resin (
It is constructed so that it can be heated at a temperature that is adjusted to a temperature below the melting point of A).

Therefore, the warp and weft yarns (1) and (2) heated by this
In this case, the surface layer resin (B) softens and melts, and the base resin (A) having a higher melting point does not soften and melt.

(50) is a crimping device consisting of a plurality of rollers (51), (52), (53), etc. disposed at a position subsequent to the heating device (40), and is used to bond both warp and weft yarns heated to the temperature range described above. It is provided so that it can be crimped from above and below, and by this crimping, both the warp and weft threads (1) and (2) are joined at their intersections by the fusion of the surface layer resin (B) which has been softened and melted by the heating. It will be integrated.

The heating device (40) and the crimping device (50) are provided with both thread support members (10) extending to the device position.
a) (10b), and thus the yarn (1) which becomes the weft thread is stretched between the yarn support members (10a) and (10b). loa) (10b).

Therefore, in the above manufacturing apparatus, if the above-mentioned multilayer tape-like yarn is used as the weft and weft yarns (1) and (2), the tape-like yarn (
1) are stretched over the pair of thread support members (10a) (10b) in a meandering manner by the rotation of the spanning device (2o), and are arranged in parallel at required intervals with the surface layers facing up and down. Tape-shaped threads (2) as warp threads fed from above and below the device are arranged parallel to the upper and lower surfaces of the threads (1) in a transverse direction by a superimposing device (3o). After that, the yarn is heated by a heating device (4o) to a temperature higher than the melting point of the surface layer resin (B) and lower than the melting point of the base resin (A) to form the surface layer resin (B).
) only in a softened and melted state, the crimping device! (50), and both weft and weft yarns (1) and (2) are fused together at the intersection of the surface layer resin (B) (B), as shown in Fig. 1 (Fig. 2). As shown in ), a nonwoven fabric of the present invention having a three-layer structure consisting of one layer of threads (1) serving as wefts and the upper and lower layers of threads (2) serving as warps can be obtained.

In the above, the width and thickness of the tape-like yarn used for the warp and warp yarns (1) and (2) and the arrangement interval between the yarns can be arbitrarily set depending on the application. ) or (2) (2) By increasing the distance between the two, the degree of opening of the net can be increased. In addition, the threads (2) (2) that become the warp threads can be arranged in alternating positions on the top and bottom as shown in the figure, or they can be arranged in corresponding positions on the top and bottom, or so that they partially overlap. In the latter case, it becomes non-net-like. In addition, in manufacturing the nonwoven fabric, since the threads (2) that become warp threads are made up of a large number of threads, it is possible to partially vary the width of the tape-like threads or to use threads of different colors partially. .

In addition, as shown in the figure, the yarn (2) that becomes the warp is coated with a synthetic resin (B) having a lower melting point on both sides with the base layer in the middle.
) is not limited to a tape-like yarn with a three-layer structure having a surface layer of (1), but also a tape-like yarn with a two-layer structure in which only one side facing the yarn (1) is a surface layer of a synthetic resin with a lower melting point than the base resin. However, if the width becomes narrow, twisting may occur in the tape-like thread, so it is preferable to use a tape-like thread with a three-layer structure as shown in the figure.

Figure 5 shows composite monofilament yarns made of two types of synthetic resins (A) ([3) with different melting points, instead of the tape-like yarns described above, as yarns (1) and (2) with a composite layer structure of weft and warp. That is, using a monofilament yarn made of a synthetic resin (A) with a relatively high melting point as a base material core and a synthetic resin (B) with a lower melting point on the surface, the same manufacturing method as described above is used. The figure shows the case when manufactured by
In the case of this embodiment as well, the threads (1) that will become the weft are arranged in parallel, and above and below it, a large number of threads (2) that are the warp are arranged in parallel and intersect with each other, and the surface layer resin (B ) is heated to a temperature above the melting point of the base resin (A) to soften and melt the surface layer resin (B), and by pressing this, the warp threads (1) and (2) are The surface layer resin (B) is fused at the intersection portion.

In this embodiment as well, the diameters of the yarns (1) and (2) and the spacing between the yarns can be set as appropriate depending on the application, and the yarn spacing and diameter of the yarns (2), which will become the warp, can be set as appropriate depending on the application. and can be manufactured in different colors.

Furthermore, according to the present invention, when the composite monofilament yarn described above is used as the yarn (1) that will become the weft, the tape-like yarn described above is used for both the upper and lower yarns (2) (2) that will become the warp. (Figure 6), or use a tape-like yarn on one side and a composite monofilament yarn on the other side (Figure 7).
(Fig.), it can be carried out by combining and integrating the surface layer resin (B) at the intersection in the same way as above, and conversely, the tape-like yarn described above can be used as the yarn (1) that will become the weft. In some cases, the above composite monofilament yarn may be used for both the upper and lower threads (2) (2) that become the warp, or a tape-like yarn may be used for one of the upper and lower yarns and a composite monofilament yarn for the other.

Furthermore, it is also possible to mix the above-mentioned tape-like yarn and monofilament yarn in the yarn (2) that becomes the warp.

In addition, in any of the above-mentioned examples, one layer of weft thread (1)
and the warp threads (2) (2)) above and below it.
Although a layered structure is shown, the present invention can also be implemented with a two-layer structure consisting of one weft layer (1) and a warp layer (2) above and below it. can.

In addition, examples of the synthetic resin that serves as the base material for the yarn of the above-mentioned composite layer structure include high-density polyethylene, polypropylene,
Typical thermoplastic resins include polyvinyl chloride, polystyrene, polyvinyl alcohol, polyacrylic, lonitrile, polyvinylidene chloride, polyamide, polyester, and copolymers belonging to these series.

In addition, the synthetic resin with a low melting point that becomes the surface layer can be used in combination with the synthetic resin (A) that becomes the base material (A).
A) has a melting point lower than A) and does not lose its properties such as tensile strength by stretching the base resin (A) at its thermocompression bonding temperature, such as low density polyethylene, ethylene-vinyl acetate copolymer, ethylene. - Acrylic acid copolymers and the like.

C Effects of the Invention As described above, the nonwoven fabric of the present invention has warp and warp yarns that are firmly bonded and integrated by thermocompression bonding between the resins in the surface layer, and has excellent peel resistance. It does not soften or melt or lose the properties such as tensile strength of the base resin, retains its original strength, can withstand use as this type of nonwoven fabric, and has excellent durability. Therefore, it can be very suitably used in various other fields, such as as a reinforcing layer for various sheet materials such as paper and synthetic resin films, as a reinforcing material for building materials, and as a net material alone.

Further, according to the manufacturing apparatus of the present invention having the above configuration, not only can the above-mentioned nonwoven fabric be efficiently manufactured without adversely affecting the base resin of the yarn, but also the yarn that will become the weft can be supported and fed. The pair of yarn supporting members that hold the weft without separating it until the above-mentioned heating and pressure bonding are performed, so the yarn that will become the weft does not loosen before being bonded by heat and pressure bonding, and this is simply a process of heat and pressure bonding. In combination with this, it is possible to reliably produce a high-quality nonwoven fabric without yarn distortion or deformation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a partially enlarged perspective view, FIGS. 3 and 4 are side and plan views schematically showing the nonwoven fabric manufacturing apparatus of the present invention, Figures 5 to 7
The figure is a partially enlarged perspective view showing another example of the nonwoven fabric. (1) (2)... Threads of weft and warp, (A)...Synthetic resin as base material, (B)...Synthetic resin with low melting point of surface layer, (10a) (10b)...・A pair of thread support members,
(20)... Yarn wrapping device, (30)... Layering device, (40)... Heating device, (50)... Pressing device.

Claims (4)

[Claims] 1. Consisting of two or more types of synthetic resins with different melting points, a composite layer structure in which the synthetic resin with the higher melting point is used as the base material and the synthetic resin with the lower melting point is used as the surface layer, each of which has a large number of threads arranged approximately parallel to each other in the warp and warp. The fibers are made to intersect in at least two layers, and are thermocompression bonded in a temperature range above the melting point of the surface layer resin and below the melting point of the base resin, so that the warp and warp threads are bonded and integrated at the intersection. non-woven fabric. 2. The threads of a composite layer structure on one or both sides are obtained by slitting a multilayer film made by laminating a synthetic resin with a lower melting point on one or both sides of a base material layer made of a synthetic resin with a relatively high melting point. The nonwoven fabric according to claim 1, which is a tape-like yarn having a multilayer structure. 3. Claim 1: One or both of the yarns with a composite layer structure are made of composite monofilament yarns having a core made of a synthetic resin with a relatively high melting point and whose surface is coated with a synthetic resin with a lower melting point. Nonwoven fabric as described in section. 4. A pair of thread supporting members arranged in parallel on both sides with an interval between them, which supports and continuously feeds the threads stretched between them in a substantially parallel manner; and two thread supporting members having different melting points. The pair of yarns is made by continuously supplying as a weft a yarn having a composite layer structure consisting of more than one kind of synthetic resin, of which a synthetic resin with a high melting point is used as a base material, and a synthetic resin with a low melting point is used as a surface layer. A device for winding the yarn between supporting members in a meandering manner, and continuously supplying the yarn of the composite layer structure as a warp to the upper surface and/or lower surface of the weft yarn stretched between the yarn supporting members, a device for superimposing the superimposed warp and weft yarns in cross directions; a device for heating the superimposed warp and weft yarns to a temperature higher than the melting point of the surface layer resin of the yarn and lower than the melting point of the base resin; and under the heating condition described above. and a crimping device that crimps the warp and weft yarns from above and below and joins them at their intersections, and the pair of yarn support members extends to the position of the heating device and the crimping device. Device.