JPH08134761A - Nonwoven fabric and its production - Google Patents

Abstract

PURPOSE: To provide a process for producing spun-bonded nonwoven fabric enabling the spread without paying special attention for longitudinal tearing of it in the case of using as an agricultural sheet and the improvement of workability. CONSTITUTION: Filaments, 2 spun through a spinneret 1 are drawn and collected by an air gun 3. The filaments are homogeneously dispersed by a dispersing apparatus 4 and spread and accumulated on a mesh belt 5. This is bonded by spot fusing by heat embossing to obtain the objective spun-bonded nonwoven fabric. In the process, the drawing speed by the air gun 3 is set at 1000-1500m/min and the drafting ratio is set at 100-400.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a large elongation and a good balance between longitudinal strength and lateral strength, and is suitable for agricultural sheets, packaging materials,
The present invention relates to a spunbonded nonwoven fabric suitable for industrial materials, medical / sanitary materials, etc., and a method for manufacturing the same.

[0002]

2. Description of the Related Art Spunbonded non-woven fabric is of a type obtained by stretching a spun filament through a round air gun or a slit air gun and then spraying it on a mesh belt with a dispersing device, and pressing the spun filament. After being cooled by the cooling air introduced into the chamber, it is drawn out through a nozzle, stretched, and sprayed on a mesh belt. These nonwoven fabrics have a filament take-up speed of 2000 to 60 from the viewpoint of productivity.
Fast as 00m / min, and draft rate is 500 ~ 1000
Therefore, the physical properties are such that the ratio of the longitudinal strength to the lateral strength is usually 2 or more and the elongation is small.

[0003]

Agricultural sheets made of spunbonded nonwoven fabric are used as a solid covering sheet for protecting agricultural products from frost and harmful insects. At this time, the sheet is stretched while being stretched in the width direction (lateral direction). However, in the current spunbonded nonwoven fabric, since the strength in the lateral direction is weak, vertical tearing is likely to occur, and workability is a problem.

The packaging material made of spunbonded nonwoven fabric is
Since it is pulled in the horizontal direction during packaging, vertical tearing is likely to occur as in the case of agricultural sheets. Further, when forming a clothes storage bag such as a laundry bag, there is a problem that heat sealability is poor and processability is poor. In the medical and hygiene materials field as well, there is a demand for improved lateral strength in final products such as surgical gowns and diapers, and nonwoven fabrics as these materials are also required to have improved lateral strength.

As a method for improving the easiness of tearing of a spunbonded non-woven fabric with respect to a tensile force in the transverse direction, Japanese Patent Laid-Open No. 5-19 is known.
As shown in No. 5403, there is a method of improving the lateral strength. However, improving the lateral strength is not sufficient to improve the tearability of the nonwoven fabric. An object of the present invention is to provide a spunbonded nonwoven fabric that is resistant to tearing in the transverse direction and a manufacturing method thereof.

[0006]

As a result of various experiments, the inventors of the present invention spin a molten resin of polyolefin from a spinneret, collect the filaments by a take-up device such as an air gun, and converge the filaments by a dispersing device. Filament in spunbonded non-woven fabric that is evenly dispersed, scattered and collected on a collecting surface such as a mesh belt, and entangled by point fusion by heat embossing and entanglement equipment such as needle punch, hot air through, water jet, etc. The take-up speed of 500-2000 m / min, preferably 100
0 to 2000 m / min, more preferably 1000 to 150
When it is set to 0 m / min, the dispersion of the filament in the dispersing device is deflected in the lateral direction, so that the longitudinal strength (flow direction strength) and the lateral strength (width direction strength) in the tensile strength of the nonwoven fabric are balanced, and It was found that the lateral strength ratio was 0.5 to 1.5.

The present invention has been made based on this finding, and has a filament take-up speed of 50 when the molten polyolefin at 200 to 300 ° C. is discharged from the spinneret.
0 to 2000 m / min, preferably 1000 to 2000 m / min
The single hole discharge amount (discharge amount per nozzle in the spinneret) is adjusted so as to be min, more preferably 1000 to 1500 m / min. In the determination of the single hole discharge rate, the relational expression of the filament take-up speed Vf (m / min) with the air gun, the single hole discharge rate w (g / min), and the filament thickness d (denier), Vf = 9000 ×
w / d is used.

According to the present invention, the filament take-up speed is 500 to 2000 m / min, most preferably 1000.
~ 1500m / min, draft rate 100 ~ 500,
Preferably, by setting it as 200 to 400, the single yarn elongation is at least 400%, the ratio of the longitudinal strength to the transverse strength of the nonwoven fabric is 0.5 to 1.5, and the elongation in the transverse direction is 6
A nonwoven fabric having a content of 0% or more can be obtained. The non-woven fabric obtained as described above not only has a good balance of longitudinal strength and transverse strength and a large elongation, but also has a draft ratio of 1 during spinning.
Since it is as low as 00 to 500, the crystallization of the resin in the filament is small and the draft rate is 500 to 100.
Compared with the conventional non-woven fabric having a value of 0, the heat-sealing property is improved.

Further, by setting the draft rate to 100 to 500, the single yarn elongation of the filament is at least 400%,
By setting the draft ratio to 100 to 400, it is possible to obtain a filament having a filament monofilament elongation of at least 500%. As a result, the elongation of the non-woven fabric is also increased, and the elongation is 60% or more, preferably 70% or more, more preferably 80% or more in the transverse direction, and as a result, it is possible to obtain a non-woven fabric in which longitudinal tearing is unlikely to occur. The unit weight of the non-woven fabric and the thickness of the thread are appropriately selected depending on the use, but the basis weight is usually 10 to 150 g / m ² , and the thread thickness is about 1 to 25 denier. A typical example of the polyolefin used in the present invention is polypropylene, which may be a propylene homopolymer or a copolymer with another α-olefin. These polyolefins may be used alone or in combination of two or more depending on the purpose. The nonwoven fabric according to the present invention includes, for example, men's, women's and children's clothing, interlinings for blouses, shirts, coats, etc., heat insulating materials used for cold-jacketing jackets, nightgowns, quilting wear, etc. For blankets, sheets, bedspreads, duvets,
For bedding and bedding such as sitting cloth, carpet, curtain, wallpaper, acoustic equipment, furniture such as molded furniture sheet, musical instrument, interior, upper, back leather, insole, toecap, boot lining, reinforcing material, etc. Lining material for bag bags, hand core, bag materials such as packing material for bag bag leather, filters for liquid, gas, dust collection, rintry wipers, wipers for various wiping cloths, tapes, battery separators, wire pushing Rolls, electronic insulation materials such as floppy disk liners, printed materials such as maps, calendars, labels, tags, envelopes, stainless stickers, envelopes, shopping bags, confectionary sacks, tea bags and other sachet materials, polishing Materials, oil adsorbents, leather base cloth, industrial materials such as various tape base materials, asphalt overlays, soil stabilizers, filtration materials, water storage underliners, Food protection materials, quicksand prevention materials, reinforcement materials, vegetation mats, concrete curing sheets, artificial grass and other civil engineering materials, roofing, floor materials, sound insulation materials, construction materials such as backings, heat insulation materials, windshield materials, Agricultural and horticultural materials such as sun protection materials, fruit protection materials, food damage prevention materials, seedling raising materials, seeding base materials, anti-frost materials, windproof materials, heat insulating materials, insect and bird protection, various coating materials, confectionery packaging, tea bags, pillows Covers, packing materials such as gloves, towels, hand towels, tablecloths, aprons, cleaning softeners and other kitchen laundry products, cosmetic puffs, gauze, shoe polish, floor polish etc., cosmetic wipes, water absorbent paper, hobby products, toiletries , Cooking supplies, book covers, tents, calendars, stationery materials, other household goods such as household goods, surgical masks, gowns, caps, CSR wraps, Anne Paddo, packaging pack, gauze, bed, sheets, bandages, eye patches, surgical tape, hospital or Babbu material base fabric such as Shikoromo, hay fever mask, drugs for medical materials such as a pressure-sensitive adhesive tape,
Examples include sanitary napkins, sanitary products such as panty shields, hygiene materials such as adult diapers, baby diapers, and diapers such as incontinence pads.

[0010]

EXAMPLE In FIG. 1, a filament 2 spun by a spinneret 1 is drawn through an air gun 3, and then spread on a mesh belt 5 by a dispersing device 4 and then entangled by a entanglement device 6 such as a needle punch. The manufacturing apparatus for spunbonded nonwoven fabric will be described. Example 1 In the apparatus shown in FIG. 1, a propylene homopolymer of MFR35 was spun at a resin temperature of 223 ° C. from a 0.85 mmφ spinneret 1 at a discharge rate of 1.41 g / min per single hole, and a filament 2 with an air gun 3 was used. Take-up speed of 1200m / mi
A non-woven fabric having a basis weight of 25 g / m ² was formed by point fusion with a filament and heat embossing at n and a draft ratio of 400. Then, the elongation of the filament and the tensile property of the nonwoven fabric were measured.

Example 2 In the apparatus shown in FIG. 1, a propylene homopolymer of MFR35 was spun at a resin temperature of 223 ° C. from a spinneret 1 of 0.6 mmφ at a discharge rate of 1.04 g / min per single hole, and an air gun 3 was used. Of filament 2 of 1200m / min
At a draft rate of 270, a filament and a nonwoven fabric having a basis weight of 25 g / m ² were formed by point fusion by heat embossing, and the elongation of the filament and the tensile properties of the nonwoven fabric were measured.

Example 3 Similarly, in the apparatus shown in FIG. 1, the MRF35 with a discharge rate of 1.5 g / min per single hole from a 0.85 mmφ spinneret.
Propylene homopolymer was spun at a resin temperature of 223 ° C and the filament was drawn with an air gun at a speed of 1000 m /
A non-woven fabric having a basis weight of 25 g / m ² was formed by point fusion with a filament and heat embossing at a min and draft rate of 300, and the elongation of the filament and the tensile properties of the non-woven fabric were measured.

Comparative Example 1 In the apparatus shown in FIG. 1, a propylene homopolymer of MRF35 was spun at a resin temperature of 234 ° C. at a discharge rate of 0.59 g / min per hole from a spinneret of 0.6 mmφ, and was spun with an air gun. At a filament take-up speed of 2500 m / min and a draft rate of 1000, a filament and a non-woven fabric having a basis weight of 25 g / m ² were formed by point fusion by heat embossing,
The filament elongation and the tensile properties of the non-woven fabric were measured.

COMPARATIVE EXAMPLE 2 Similarly, in the apparatus shown in FIG. 1, MRF35 with a discharge rate of 0.40 g / min per single hole from a spinneret of 0.6 mmφ.
Propylene homopolymer was spun at a resin temperature of 228 ° C and the filament was drawn with an air gun at a speed of 1200 m /
A non-woven fabric having a basis weight of 25 g / m ² was formed by point fusion with a filament and heat embossing at a min and draft rate of 700, and the elongation of the filament and the tensile properties of the non-woven fabric were measured.

The above measurement results are shown in Table 1 below.

[0016]

[Table 1]

The tensile test methods for nonwoven fabrics in Examples and Comparative Examples are as follows. Test piece size 200 mm x 50 mm Test method Check interval 100 mm Test speed 300 mm / min Measured at room temperature The filament single yarn elongation test method is as follows.

Test Method Between Checks 20 mm Test Speed 100 mm / min Measured at Room Temperature The heat sealability evaluation method in Examples and Comparative Examples was performed as follows.

Fusing seal method Seal temperature 400 ° C. Evaluation method Sensory strength is evaluated in three grades of ○ △ × ○ Very good △ Good × Poor

[0020]

When the non-woven fabric according to the present invention is used as, for example, an agricultural sheet, it is possible to work without paying excessive attention to vertical tearing during spreading of the agricultural sheet,
Workability can be improved. Further, when used as a packaging material, not only tearing due to lateral pulling can be prevented, but also heat sealability can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a spunbond nonwoven fabric manufacturing apparatus.

[Explanation of symbols]

1 ... Spinneret 2 Filament 3 Air gun 4 Dispersing device 5 Mesh belt 6 Entangling device

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Claims (9)

[Claims] 1. A polyolefin nonwoven fabric produced by the spunbond method, wherein the ratio of tensile strength to longitudinal strength is 0.5 to 1.5 and the transverse elongation is at least 60%. Non-woven fabric. 2. The filament take-up speed is 500 to 2
000m / min and draft rate is 100 ~ 500
And a method for producing a polyolefin non-woven fabric by the spunbond method. 3. The filament take-up speed is 1000-1.
The method for producing a polyolefin non-woven fabric by the spunbond method according to claim 2, wherein the draft rate is 500 m / min and 100 to 400. 4. A device manufactured by the manufacturing method according to claim 2.
A nonwoven fabric having a tensile strength longitudinal strength / lateral strength ratio of 0.5 to 1.5 and a transverse elongation of 60% or more. 5. A device manufactured by the manufacturing method according to claim 2.
A non-woven fabric having a tensile strength longitudinal strength to transverse strength ratio of 0.5 to 1.5 and a filament filament elongation of 400% or more. 6. An agricultural material using the nonwoven fabric according to claim 1. 7. A packaging material using the nonwoven fabric according to claim 1, 4, or 5. 8. An industrial material using the nonwoven fabric according to claim 1, 4, or 5. 9. A medical / sanitary material using the nonwoven fabric according to claim 1.