JPH0735631B2 - Method for manufacturing nonwoven fabric laminate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a nonwoven fabric laminate, and more particularly, to ventilation in fields such as agricultural and civil engineering fields such as soil water supply / drainage materials and clothing fields such as padding. The present invention relates to a method for producing a non-woven fabric laminate using a thick, low-density non-woven fabric that is widely used in industries that require water resistance and water permeability.

[Prior Art] Lamination of nonwoven fabrics to obtain a laminated structure has been performed in various fields, and since various materials can be obtained by laminating, the importance thereof has been increasing in recent years.

The conventional laminating methods are roughly classified into a method of laminating and adhering by using an aqueous emulsion or a solution type liquid adhesive, and a powder, a film, or a low-melting fiber web by using a thermoplastic resin. It can be classified into a method of bonding layers by placing them between layers and heating and melting them.

As other special methods, there are known a laminating method using a special resin that is cured by irradiation with ultraviolet rays or an electron beam, and a mechanical laminating method using a needle punch or the like.

[Problems to be Solved by the Invention] In the conventional method for laminating a preformed non-woven fabric, heating and heating of the non-woven fabric is performed regardless of whether the liquid adhesive is used or a thermoplastic resin is used. The pressure means was an essential component. In other words, when a liquid adhesive is used, a drying step is necessary, and since the adhesive force between the layers is insufficient by simple drying, it is necessary to heat dry while applying an appropriate pressure to the laminate. did. Further, when a thermoplastic resin is used, the time required for heating can be shortened as compared with the case where the adhesive is used, but in order to obtain a sufficient interlayer adhesive force, the pressure condition is liquid bonding. It had to be much higher than when using the agent.

In the conventional laminating method that requires heating and pressurization, when the non-woven fabric is thin or has a relatively high density, the delamination can be performed by appropriately selecting the manufacturing conditions. Although it is a method of obtaining a product of excellent quality that does not occur, when the nonwoven fabric is thick or has a low density, the thickness of the nonwoven fabric can be reduced by heating and / or pressing. On the other hand, if the manufacturing conditions are selected such that the thickness does not decrease, the adhesive strength between the layers becomes insufficient, resulting in delamination.

In order to solve these problems, using a special resin that is cured by irradiating the ultraviolet ray or the electron beam, it is also known to laminate and bond at low temperature and low pressure, but these resins are It is expensive and at the same time requires a large amount of investment in production equipment, which is not economical.

In addition, UV curable resin can be applied only to extremely thin materials that have a low degree of light shielding against ultraviolet rays, and even when electron beam curable resin is used, in order to apply it to thick materials, it is necessary to prevent leakage of electron beams. These methods were also unsatisfactory because of the large capital investment required for them.

Further, a lamination method by a mechanical bonding method such as needle punching can be applied to a fiber web before the fibers are bonded to each other or a loose felt-like nonwoven fabric, but the fibers are previously bonded with an adhesive or the like. It could not be applied to the non-woven fabric bonded with, and had no general versatility.

[Means for Solving Problems] The present invention provides a method for producing a nonwoven fabric laminate, wherein at least one layer of the laminate is a thick low-density nonwoven fabric having a thickness of 1 mm or more and an apparent density of 0.1 g / cm ³ or less. In the non-woven fabric layer,
On one or both surfaces of the other layer, an adhesive consisting of a thermoplastic resin, by using a heating air flow by a heating and melting spray device, is discharged and applied in a granular or fibrous form,
Then, the present invention relates to a method for producing a nonwoven fabric laminate, which comprises polymerizing and cold pressing.

[Operation] The present invention relates to a method for producing a non-woven fabric having at least one thick low-density non-woven fabric, and an object thereof is to laminate and bond the non-woven fabric without reducing the thickness of the non-woven fabric.
The point is to use a heating and melting spray device.

The non-woven fabric used in the present invention has a thickness of 1 mm or more and an apparent density of 0.1 g / cm ³ or less, but such a thick low-density non-woven fabric is heated and pressed as described above in the conventional laminating method. It was extremely difficult to obtain a strong interlayer bond without reducing the thickness because the thickness decreases due to the effect of the thickness of less than 1 mm or the apparent density of 0.1 g / cm ³ . Since those exceeding the above level can obtain sufficient quality even by the conventional laminating method, the manufacturing method of the present invention can be applied to these, but they are not the subject of the present invention.

Next, the thermoplastic resins used in the present invention will be explained. These are those which are spray-applied to the surface of the laminated material by a heating and melting spray device and can firmly adhere the layers of the laminated material to each other. Is 60 to 200 ° C., preferably 90 to 140 ° C. These resins include polyethylene-vinyl acetate copolymer system,
There are polyolefin-based, polyamide-based, polyester-based, polyurethane-based, etc., and any one suitable for the properties of the laminated material can be selected from these, but polyethylene-vinyl acetate copolymer or polyolefin-based resin, terpene resin, etc. The one obtained by blending the above tackifier has a low melting point and has a long remaining time of tackiness after spray application, and thus can be said to be the most suitable one because strong interlayer adhesion can be obtained.

The present invention will be described below with reference to the drawings.
2 is a cross-sectional view of the nonwoven fabric obtained by the method shown in FIG. 1, which is a process schematic diagram showing an example of the method for producing a nonwoven fabric laminate according to the present invention.

FIG. 3 and FIG. 4 are a side view and a front view showing an example of the discharge part of the heating and melting spray device used in the present invention.

In FIG. 1, a thick low-density nonwoven fabric A1 is sent out,
Then, a predetermined number of tubular bodies 3 are fed onto the nonwoven fabric A in parallel with the flow direction of the process.

Next, the thermoplastic resin is discharged and applied by the heating and melting spray device 4, and an example of this spray device will be described. The spray device includes a melting portion for melting the thermoplastic resin and a spray nozzle for a fixed amount of the melted resin. It is composed of a fixed amount supply section for conveying to a container, and a discharge section having a resin discharge port 5 in the center for discharging the molten resin in a granular or fibrous form and a high-speed heated air discharge port 6 around it.

As an apparatus having these configurations, there are a melt tank, a liquid feed pump, a well-known hot melt spraying apparatus having a spray nozzle, an apparatus using an extruder known as a melt blow method, etc. From the viewpoint of workability, it is advantageous to use the hot melt spray device as shown in FIGS. 3 and 4.

In the melting part, the thermoplastic resin is melted, but in order to prevent resin deterioration due to heating, it is preferable that the temperature is not lower than the melting point of the resin and not higher than 50 ° C, and a large amount at a time to shorten the residence time. It is desirable not to melt. The supply device used in the constant amount supply unit may be any gear type pump, screw type pump, pump using air pressure, etc., as long as it can convey resin at a constant amount and a constant pressure. In addition, since the resin is adjusted to have a viscosity suitable for discharging in the constant quantity supply unit, generally, a heating device capable of adjusting the resin viscosity to 500 to 20,000 centipoises, preferably 700 to 2000 centipoises should be provided. Is desirable. The discharge part needs to apply the resin uniformly on the laminated material.
Due to the structure in which the entire discharge portion is movable or the structure having a plurality of discharge ports, the structure is such that unevenness does not occur when applied. Also, the nozzle orifice diameter of the discharge port is 0.3-3 mm,
Optimum ones of 1-2 mm are used.

The heated air is preferably higher than the resin temperature, and normally air heated to a temperature above the melting point of the resin and in the range of 10 to 100 ° C. is suitable.

The thermoplastic resin discharged from the above spray device is uniformly and uniformly applied on the surface of one or both of the laminated materials forming the laminate, but the resin discharged from the spray nozzle is rapidly cooled, It is desirable that the distance from the spray outlet to the surface of the laminated material is 20 to 500 mm, preferably 50 to 150 mm.If this distance is less than 20 mm, the laminated material is heated and the thickness is reduced in a cooling press, which is the opposite. At 50
If it exceeds 0 mm, the resin is excessively cooled and the adhesiveness is deteriorated, which is not suitable.

Next, while the resin applied on the laminated material remains tacky, another laminated material is immediately polymerized and pressed by a cooling press roll to firmly bond the layers. Distance from sprayer to cooling press roll is 20 to 20
It is preferably 0 cm, and when it exceeds 200 cm, the adhesiveness of the resin is lost depending on the type of the resin and the production rate, resulting in poor interlayer adhesion, which is not preferable.

The cooling press is composed of two or more rolls or flat plate presses whose pressure can be adjusted, and press-presses the laminate to give a strong adhesive force between the layers. Cooling as used herein means a temperature at which the thermoplastic resin can be solidified. Therefore, the pressing temperature is generally a temperature equal to or lower than the softening point of the resin, but the production rate is improved. Therefore, it is preferable to use a press roll having a structure capable of positively cooling the inside of the roll with cooling water or the like.

By the above manufacturing method, the thick, low-density nonwoven fabric is hardly or not heated at all. Therefore, even when a pressure is applied during the pressing, the thickness and density of the non-woven fabric hardly change, so that a laminate having desired properties can be obtained.

Further, the use of the heating and melting spray device, which is the gist of the present invention, not only enables the interlayer adhesion without directly heating the laminated material, but is very difficult by the conventional method,
Or it was impossible, it was thick and the apparent density was 0.03 g /
It also makes it possible to easily laminate and bond extremely porous non-woven fabrics of cm ³ or less. In other words, in these extremely porous nonwoven fabrics, the liquid or powder adhesive permeates inside the nonwoven fabric and the adhesive is not evenly applied to the surface in the conventional method. However, when the heating and melting spray apparatus of the present invention is used, the heating air flow is adjusted to discharge the thermoplastic resin used as the adhesive. Since the shape can be easily made into a fibrous shape or a cobweb shape, the resin does not penetrate into the inside of the non-woven fabric and the non-woven fabric surface can be applied extremely uniformly, so that the quality of the non-woven fabric can be improved. A strong interlayer adhesion can be obtained without any damage.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1 A fibrous web mainly composed of polyester fibers (3 denier, 64 mm long) was impregnated and bonded with an acrylic emulsion to prepare a thick low-density nonwoven fabric having a basis weight of 120 g / m ² and a thickness of 4.5 mm. On this non-woven fabric, long diameter 5 mm with holes on the side,
An elliptical tubular body with a short diameter of 2 mm is placed 50 m in parallel with the product flow direction.
Arranged at m intervals, and then using a hot melt sprayer, a melting point of 120 ° C., a melt viscosity at 180 ° C. of 1000 centipoise polyethylene-vinyl acetate copolymer resin was uniformly applied to the nonwoven fabric surface at 30 g / m ² . . The spraying conditions at this time are as follows: melting part temperature 140 ° C, fixed amount supply part temperature 180 ° C
The discharge part temperature was 180 ° C and the spray air pressure was 1.3 kg / cm ² .

Then, the same non-woven fabric was immediately laminated on the non-woven fabric to which the resin was applied, and the laminated body in which the tubular body was arranged in the intermediate layer was placed at a distance of 40 cm from the resin discharge port, and the surface temperature was 25 It was crimped by a cooling press roll at ℃.

The non-woven fabric laminate obtained by the method of the present invention described above has a thickness of 8.7 mm, a peel strength between layers of 170 g / cm, does not reduce in thickness, and exhibits excellent quality without fear of delamination, for agricultural civil engineering. It was the best water supply and drainage material.

[Comparative Example 1] The same nonwoven fabric and tubular body as in Example 1 were used, and the melting point was 120 ° C instead of resin coating by hot melt spraying.
Then, after forming a laminate having a structure in which a polyethylene-vinyl acetate copolymer-based resin film having a thickness of 0.03 mm is sandwiched, the film is passed through a heat roll having a surface temperature of 140 ° C. to melt the film to bond the layers. A non-woven laminate was created.

The laminate obtained by this method had a thickness of 3.2 mm and an interlaminar peel strength of 26 g / cm, the thickness was drastically reduced, and the interlaminar delamination was extremely easy to produce and was of little practical value.

In addition, in both Examples and Comparative Examples, the peel strength was measured by performing constant speed T-type peeling on a test piece having a width of 5 cm at a speed of 100 mm / min.

Example 2 Highly crimpable polyester fiber (6 denier, 76 mm long)
A thick low-density non-woven fabric having a basis weight of 60 g / m ² and a thickness of 5 mm and having a melting point of 120 ° C. and 180 ° C. under the same conditions as in Example 1.
20 g / m ² of polyester resin having a melting point viscosity of 600 centipoise at
After laminating a tricot knitted fabric having a thickness of m ² and a thickness of 0.2 mm, a non-woven fabric laminate was obtained by the method of the present invention by pressing with a room temperature press roll installed at a position 30 cm from the discharge port.

The obtained laminate has a thickness of 5.2 mm and an interlaminar peel strength of 120 g / cm.
It was the most suitable as a material for cotton padding for clothing and brassiere cups, with no risk of delamination.

Comparative Example 2 The same non-woven fabric as in Example 2 was coated with an adhesive having an acrylic emulsion thickened so that the solid content was 20 g / m ² , and then the same tricot knit as in Example 2 was laminated. Then, a felt dryer capable of pressure drying was passed and dried at a temperature of 120 ° C. to obtain a nonwoven fabric laminate.

The obtained laminate has a thickness of 3 mm and an interlaminar peel strength of 18 g / cm,
Along with partial peeling, the adhesive penetrated into the inside of the non-woven fabric, impairing the texture of the non-woven fabric, and the performance was completely impractical.

[Effects of the Invention] In the method for manufacturing a nonwoven fabric laminate of the present invention, since the structure of the device is extremely simple, the installation space is small, and as a result, it is advantageous for monitoring work and preparation in production, and greatly improves production efficiency. Higher quality and easier quality control.
Moreover, with the conventional lamination method, production is difficult,
In the present invention, a porous material, a flexible material, or a stretchable material, which has a very poor production efficiency, is not heated in the present invention, and a tension for preventing wrinkles and slippage during production is unnecessary. Therefore, it is possible to manufacture various laminated bodies which have not been used conventionally by using various materials which are conventionally unsuitable as a laminated material.

Further, the non-woven fabric laminate produced by the production method of the present invention has almost no thickness reduction as described above, and since the adhesive is applied in a granular or fibrous form, the air permeability and water permeability of the laminate material are not impeded at all. . For this reason, in the conventional method, there is no risk of clogging due to the adverse effect of the adhesive, as well as an increase in ventilation resistance or water resistance due to a decrease in thickness or an increase in density.
Enables stable production of products with excellent water permeability. These are very useful as clothing materials, agricultural civil engineering materials, air conditioning filter materials, and the like.

Therefore, the method for producing a nonwoven fabric laminate of the present invention is economical,
It is a manufacturing method that is excellent in workability, versatility, etc., and is far superior to the conventional method capable of stably producing a product of excellent quality.

[Brief description of drawings]

FIG. 1 is a process schematic diagram showing an example of a method for manufacturing a nonwoven fabric laminate of the present invention. FIG. 2 is a cross-sectional view of a laminate obtained by the method of FIG. 1 with a tubular body inserted between the layers. FIG. 3 and FIG. 4 are a side view and a front view showing an example of the discharge part of the heating and melting spray device used in the present invention. The numbers in the figure are 1 ... Nonwoven fabric A, 2 ... Nonwoven fabric B 3 ... Tubular body, 4 ... Melt spray device 5 ... Resin discharge port, 6 ... Air discharge port, 7 ... Discharge part heater

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location D06M 17/00

Claims (3)

[Claims] 1. A method for producing a nonwoven fabric laminate, wherein at least one layer of the laminate is a thick, low-density nonwoven fabric having a thickness of 1 mm or more and an apparent density of 0.1 g / cm ³ or less. On one or both surfaces of the layer, a thermoplastic resin adhesive is spray-applied in a granular or fibrous form using a heating air spray device with a heating air flow, and then polymerized and cooled and pressed. A method for producing a nonwoven fabric laminate, comprising: 2. The method for producing a nonwoven fabric laminate according to claim 1, wherein a tubular body, a linear body, or a net-like body is inserted and laminated in the intermediate layer of the nonwoven fabric laminate. 3. The production of the non-woven fabric laminate according to claim 1, wherein the distance from the spray outlet to the surface of the coating layer is 20 to 500 mm, and the distance from the spray device to the cooling press roll is 20 to 200 cm. Method.