JPS5841960A - Production of nonwoven fabric - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a long-fiber nonwoven fabric made of a thermoplastic polymer. This relates to a method for producing nonwoven fabrics that is stretched at a certain magnification, then passed through a slit-type air sucker to open and deposit the fibers. (In contrast to the law, it is stretched between multiple roll groups with different rotational speeds, and the surin) W air sucker has the function of simply opening the web, which dramatically reduces the amount of pressurized air used. To provide a method for manufacturing a non-woven fabric which is low in cost, aims at high strength due to the stretching of yarn, and allows the width of the non-woven fabric to be freely changed! be.

Conventionally, it has been known to melt-spun a thermoplastic polymer, pull it using an air sucker, thin it, open it, and deposit it to form a web consisting of long fibers.

This method is generally called the spunbond method, and the thermoplastic polymers used include wood, polyester, polyamide, polyolefin, etc., and many of them have already been commercialized. Representative patents related to the spunbond method include:
Japanese Patent Publication No. 37-4993 is known, in which the yarn is pulled at high speed by an air sucker or rotating roll, electrostatic charge is applied to the yarn by corona discharge, and the yarn is opened, and air is blown in the lateral direction of the net conveyor. A wide nonwoven fabric is manufactured by lining up soccer or rotating rolls.

In the air sucker traction method, compressed air is used as the compressed fluid, and it is thought that a relatively low pressure of 1 to 9 kg/dl G is used. The pulling speed of the yarn is usually calculated from the denier of the single yarn and the discharge amount per discharge hole of the spinneret, and generally from the viewpoint of productivity, it is often Skm 1 minute or more. In particular, using polyethylene terephthalate as a material,
When producing a nonwoven fabric by thermocompression bonding, a calculated yarn speed of 5 km/min or more is required in order to suppress thermal shrinkage during thermocompression bonding. There are usually means to increase the yarn speed, such as shortening the distance between the air sucker and the spinneret, increasing the spinning temperature, increasing the pressure, and reducing the number of fits in the air sucker. Usually, it is preferable to increase the pressure to maintain productivity and prevent thermal deterioration of the polymer. For this reason, in the spunbonding method using air sucker traction, the amount of pressurized air used in the product cost, especially the electricity cost for producing pressurized air calculated as utility costs, is large. You need an energy-saving process that uses less energy.

On the other hand, a technique is also known in which a rotating roll is used between an air sucker and a spinneret, and the drawn yarn is spread through the air sucker. For example, Tokuko Sho 42-2599
In No. 8, the yarn is threaded onto a group of multiple spinning and drawing rolls lined up in the width direction of the net conveyor, and is made into a web using a nine-spread air sucker that corresponds to the spinning and drawing rolls. Wide nonwoven fabrics with a width of 5 m or more are being produced.

In such a method using multiple spinning and drawing rolls (hereinafter referred to as "individual roll pulling method"), the width direction of the nine nibs (even if the air suckers for opening are lined up in the right angle direction, the reeds are not aligned at an angle other than the right angle). It is normal for a large number of air suckers to be lined up (sometimes lined up), and since the position of the air sucker corresponds to the stretching roll, its position remains unchanged.

Therefore, in conventional nonwoven fabric manufacturing techniques, regardless of whether air sucker traction or individual roll traction methods are used, the width that can be produced by the nonwoven fabric is the same as the width that can be produced by that process, and the width cannot be intentionally changed. Spunbond nonwoven fabrics are currently being used quite widely, and the original mass production of small variety items has changed to a multi-item production system that is more suitable for a variety of uses. The reality is that wood is available in various widths and lengths.

Regarding the length, there is no problem because it is usually dealt with using a rewinding machine, but regarding the width, conventionally it was possible to deal with it by cutting a wide nonwoven fabric in the width direction with a slitter etc. and then rewinding it. is the reality. This corresponds to the packaging ability of producing various widths as the uses of non-woven fabrics have expanded in recent years. The question is whether

For example, considering a manufacturing machine capable of producing a nonwoven fabric with a width of 3 m, it is difficult to efficiently produce a nonwoven fabric with a width of 2.5 m using conventional technology. This is because, in the conventional technology, the air sucker or rotating roll is spread to the full width of the net conveyor, and narrowing the width means not using a part of the width and stopping it, which reduces productivity. do. Decreased productivity always leads to increased costs, which is obviously not desirable.

Conventionally, the remaining part of a wide nonwoven fabric is cut to the required width, and if it cannot be sold commercially (or has no use), it is discarded as a waste, or it is used as a monomer as a raw material, or it is granulated and made into chips. The only way to recover it is to collect it as a product, which is definitely a waste compared to selling it as a product.

The present invention relates to a process for manufacturing such a wide nonwoven fabric, particularly a process for manufacturing a nonwoven fabric whose width can be freely changed. That is, the present invention is a method for producing a nonwoven fabric in which a thermoplastic polymer is melt-spun to roll-stretched and opened using an air sucker. The 10th roll group, the 20th roll group, each consisting of two or more roll groups each having a narrower roll width than the roll width, or the 3rd roll group as necessary.
Stretching is carried out between the slit-type air sucker and the drawing roll, and a corona discharge device is used together with a yarn regulating device to throw sand between the slit-type air sucker and the stretching roll, to regulate the width of the yarn, and to charge the yarn. This is a method for producing a nonwoven fabric whose width can be freely changed by making it freely movable.

A spunbond method using a slit mold as an air sucker is already known, but the width cannot be changed freely using this method alone. By combining the roll stretching device and the corona discharge device as in the present invention and by making the yarn regulating device freely movable, it becomes possible to freely change the width of the yarn.

The thermoplastic polymer according to the present invention includes general polyethylene terephthalate, polybutylene terephthalate, copolyesters containing inoheptalic acid, adipic acid, etc., nylon 6°12.64, 610. Alternatively, any material that can be melt-spun and stretched may be used, such as polyamides made of copolymerized or blended polymers thereof, polyolefins made of polyethylene/polypropylene, etc. In this case, a matting agent, a heat stabilizer, a coloring agent for the purpose of doping, an inorganic salt such as lithium chloride, fine metal powder, carbon black, etc. may be contained.

The air soccer used in the present invention is a wide slit type air soccer. The method of arranging a large number of individual small circular air suckers could not eliminate the streaks (areas with thin areas) between the air suckers. In this case, the air soccer is arranged in a direction perpendicular to the traveling direction of the net conveyor. The method of arranging air suckers (multiple slit-type or circular-shaped air suckers) at an angle other than right angles to the net conveyor increases the size of the net conveyor, and it is necessary to use a stretching roll to produce a nonwoven fabric with a certain width. , the number of air suckers is large,
It is not practical because equipment costs will rise. In the present invention, it is preferable to install the slit-type air suckers in a perpendicular direction to the traveling direction of the net tone pair, but they may be installed diagonally.

A typical slit-type air soccer is shown in Figure 1. In Fig. 1, (11) is a thread guide hole, and in the case of the present invention, this thread guide hole is rectangular (rectangular shape), and its width is much larger than that of a slit.Normally, this width is It is set according to the maximum width of the manufacturing equipment.This thread guide hole is partitioned across the entire width, and no partition walls similar to walls are passed through.Normally, the width of this slit is several millimeters.(2 ; is an air introduction part, which is arranged on both sides of the thread guide hole, but may be placed only on one side. (3) is an air tank), in order to uniformly blow out air from the air introduction part in the width direction. Acts as a buffer tank. Gear mechanism of air inlet, usually 1 m.
It is preferable that the width be 1 m or less and that there be no partition walls in the width direction. In the case of a slit-type air sucker, the key point is the air introduction part (2), and the dimensional uniformity of this part determines the air ejection speed and uniformity in the width direction, so it needs to be precisely machined. A slit-type air sucker is used in the normal spunbond method, that is, an air sucker traction method, and a large number of melt-spun yarns are directly taken up by the air sucker, and in order to increase the yarn speed, the spinning machine is
Normally, the distance to the air sucker yarn guide hole is shortened to the extent that there is no fusion between the single yarns of the yarn, and due to the heat of the yarn guiding the yarn to the air knit soccer, There is a high possibility that distortion will occur in the air sucker body, and the larger the width, the greater the effect. According to the present invention, since the slit-type air sucker for fiber opening is guided with a yarn having a low yarn temperature (after spinning and drawing), there is no need to take into account the distortion caused by the heat of the air sucker, and the initial accuracy can be improved. can be maintained, making it difficult for web dispersion spots to occur. In addition, in FIG. 1, (4nti air channel) is shown.

The drawing process is carried out between a group of rolls narrower than the width of the opening air sucker.A typical process of the present invention is shown in FIG. (
5) is a chip hopper, (6) is an extruder, (7) is a spin head, (8) is a spun yarn, and (9) is a first drawing machine.
0-ru group, heating device for aert heat setting, aυ is the second
0-le group. When performing multi-stage stretching, the 20th
A 30th or more roll group may be provided after the roll group αυ to perform two-stage stretching or multi-stage stretching. The roll group used here is preferably a wide roll group of 5 or 7 used for tow drawing or monofilament, and if necessary, a take-up or delivery roll is provided. It is preferable for the melt-spun yarn to be held on a group of five or seven rolls and not wrapped on a single roll for the subsequent opening process. It is preferable to divide the yarn into yarn groups corresponding to the later yarn regulation device and draw the yarn at the time of entering the stretching roll.

The stretching roll group may have a built-in heater if necessary. Heating device (11m can be a regular hot plate.Q
Ri is a slit type soccer, I is a net conveyor, (I!
19Fi embossing roll, αQ is rolled up nonwoven fabric, a
η indicates a winder. Q3 is a yarn regulating device.

The present invention is characterized by installing a combination of a yarn regulating device for widening the yarn and a corona discharge device for applying an electrostatic charge to the yarn between the drawing roll group and the slit-type air sucker. The yarn regulating device and the corona discharge device are made freely movable, and the width of the nonwoven fabric to be produced can be freely changed.

In nonwoven fabric manufacturing equipment, there is almost no known method that allows the width to be freely changed without deteriorating productivity. In the present invention, the yarn regulating device includes:
A regular thread guide may also be used. In this case, the yarn exiting the drawing roll is regulated as a whole within the width of the drawing roll by the first stage yarn regulating device, and after being expanded to the width of the slit-type air sucker for opening, the yarn is spread. let

In FIG. 3, the vicinity of this slit-type air sucker for fiber opening is shown. (13 is the yarn regulating device LJ for regulating the width of the yarn), D is the distance between the yarn regulating devices on the air sucker, and by changing this distance, the width of the nonwoven fabric manufactured can be changed. can be changed. As shown in FIGS. 3 and 4, it is necessary to provide a corona discharge device (11) between the lower part of the yarn regulating device and the slit-type air sucker.
The needle electrode and roll target system disclosed in 5S is preferred. In this case, the needle spacing of the needle electrode is 0.5~
It is 5 cM and has a -row arrangement. In FIG. 3, the needle electrode is shown as (18a) and the roll target is shown as (18b).

FIG. 4 shows an example in which it is incorporated into the lower air channel of the air sucker (8). It is preferable that the distance between the roll target and the needle electrode is 10 to 40 mm, and that the roll target has a smooth surface and rotates freely when the yarn comes into contact with it. The voltage applied to the electrodes used for corona discharge is -10 to -70 kV, and the limit voltage that does not cause arc discharge depends on the distance between the roll target rattle needle electrodes, and it is common to apply a voltage that is close to the point where arc discharge occurs. preferred.

The corona discharge device may be provided in one stage, but if the number of yarns is large, it is preferable to arrange multiple stages in series. In FIG. 3, two stages of corona discharge devices are arranged in series.

The corona discharge device may be a combination of a flat target and a needle electrode other than such a roll target. At that time, the corona discharge device may be partitioned with an insulator or the like. The yarn that has passed through the four-way discharge device is guided to a slit-type air sucker and opened. In the case of a round air sucker described in a separate Japanese Patent Publication No. 57-4995 as an air sucker for fiber opening, unevenness occurs when changing the width, which is not preferable. The thread is always guided into a slit-type air sucker, and the negatively charged thread inside the air sucker is repelled by the electrostatic charge, and is evenly distributed in the air channel in a slit-like pattern.
It eliminates streaks and eye spots. The opening state of the yarn varies depending on the single yarn denier, the number of filaments, the voltage used in the corona discharge device, the distance between the needle electrode and the target electrode, etc., but D in Figure 3 should be set within approximately 20 cPR. In this case, a uniform nonwoven fabric can be obtained. This limit of D varies depending on the spinning conditions, etc., so it does not mean that it is impossible to achieve %20cy11 or more.

The amount of pressurized air used in the slit-type air sucker is extremely small compared to the normal spunbond method. This is because the function of drawing and thinning the yarn can be carried out by the drawing roll, and the function of opening the yarn can be performed by the slit-type air sucker for opening the fiber.

Regarding the single filament opening property of the yarn, it is preferable that the amount of air pressure used is small, but if it is extremely small, the charged yarn will clog inside the air sucker, which is unfavorable, and there is an optimum amount of air pressure that is determined for each air sucker. do.

The yarn that has passed through the air sucker is deposited on the net conveyor. If the deposited web still has an electric charge, it will cause the web to turn over, so it is preferable to remove the electric charge this time. Static electricity is removed using general steam or water spray, or a general static eliminator, and the web is generally heat-pressed with an embossing roll and then wound up as a non-woven fabric, but in some cases, adhesives such as oven heating or needle punching may be used. It doesn't matter if it's just a means.

This is because the nonwoven fabric according to the present invention allows the position of the yarn regulating device to be changed freely, and because the corona discharge device is used, single fiber dispersibility can be improved, and even if the width is changed, it does not lead to myositis. The yarn constituting the nonwoven fabric according to the present invention has a high single-filament strength because it has undergone a drawing process, and also has the advantage that it can be changed quite freely from a fine denier to a thick denier. The nonwoven fabric according to the present invention can be made by lightly thermocompression bonding and resin processing, electric wire wrapping made of polyethylene terephthalate, agricultural materials, civil engineering materials processed by needle punching, roof ink materials, and packaging made of nylon. It can be used in a wide variety of materials, such as carpet base fabrics made of polypropylene, oil catchers, etc.

Examples will be described below.

Example 1 Polyglopyrene 55 manufactured by Chisso Corporation as a thermoplastic polymer
Using 056 (melt flow rate: 4-0), 0
．． A total of 992 filaments were spun at 280° C. using a 23φ×124 hole spinneret with 8 spindles. Stretching is the second
Using six rolls with a roll width of 20 crn for the 10th roll group shown in the figure and 7 stretching rolls of the same width as the M20 roll group, the 10th roll speed was 600 m/min, and the 20th roll speed was set to 600 m/min. The speed was set at 1,000 m/min. The heating device is not used on the bottom side of the main body. The discharge amount is j7D per hole, 1
Set at 67f/min, calculated single yarn denier #'i1.
5 denier.

In front of the 10th loop group, the fibers were divided and drawn into eight yarn groups using a yarn guide, and then passed through a slit-type air sucker having a width of 1.27 FI. At this time, the distance between the yarn regulating devices (D in FIG. 3) was set to 13, and the corona discharge devices were set in two stages.

Five types of needle electrodes with a pitch of 4U were used, and a normal separator roll was used as the roll target. The voltage was -25 kV, and the distance between the needle electrode and the roll target was set to 1B. Pressure pressure Fi1 used for fiber opening
kg/cIltG, a very uniform nonwoven web was obtained. The web was thermally bonded with a textured embossing roll having a surface temperature of 141° C., and exhibited a basis weight of 421/G, tensile strength of 10.2 kg15 tM width tearing strength (Elmendorf method) of 0.7 kp.

Example 2 Polyethylene terephthalate (
Using an intrinsic viscosity of Oj 4 ), spinning was carried out using 8 spindles of 0.23φ x 246 holes at 295° C. with a discharge rate of D per hole and 3597 minutes.

! The push roll moved the 10th rule group for 7 minutes, then the 2nd
The zero group was set at 2000 m7 minutes. Using a 140°C hot grate as a heating device, a nonwoven fabric with a basis weight of 50 f/rf was obtained by pressing with an embossing roll at 200°C, and then processed with a PVA-based resin. The obtained nonwoven fabric has a basis weight of 56y/gold, and a tensile strength of 17.5kllScm.
It showed a wide range of high strength.

Example 3 Polyglopylene 85 manufactured by Chisso Corporation as a thermoplastic polymer
056 was used for spinning under the same conditions as in Example 1. At this time, when the distance of the yarn regulating device was changed from 15 cm to 9 cm, the widths of the nonwoven fabrics that could be manufactured became 943 and 58 cIn, but by adjusting the speed of the net conveyor, the fabric weight was 40! A uniform nonwoven fabric with a rating of 9/G was obtained.

Example 4 Polypropylene s manufactured by Chisso Corporation as a thermodustable polymer
5os6 (:melt 70-ray) (ASTMD-12
Spinning was carried out at 280°C with a total of 992 filaments using 8 spindles of 0.23φ x 124 holes using a 58230°C 2.16cm (measured value at 1ill) of 4]. Spinning and drawing were carried out using spin draw equipment of 1g2 diagram.
- 500 m/min for group 20, 1,000 m for group 20
It was rotated for 1 minute and cold-stretched to a single yarn of 1.5 denier at a yarn speed of 1,00 θm/min. Stretching was carried out using 6 or 7 rolls with a roll width of 20 cIn. In the case of polypropylene, shrinkage occurs during the process of forming a web after leaving the 20th loop, so the single yarn denier becomes slightly larger. Introducing the 20th rule group to the soccer, 9/cI to a pressure of 2.0
Open the fibers with the pressure of IG. When threading, each thread of each spindle was guided through eight thread regulating devices, that is, ceramic thread guides, and the distance between the guides was set to 13 clrI. In this example, since the yarn was guided through eight yarn guides, the web width was approximately 1 m. For the filament, two needle-like electrodes are installed in the air channel at the bottom of the slit-type air sucker directly below the thread guide. The needle-like electrode is set at Fi20 between the needle-like electrode and the target electrode, with the slit spacing of the air channel having 10 needles at a pitch of 2, and the fibers are opened by applying a voltage of -29 kV. , a web with good single fiber opening was obtained, and the temperature was 142°C.
A nonwoven fabric with a basis weight of sat was obtained by thermocompression bonding using an embossing roll. The obtained nonwoven fabric exhibited a tensile strength of 14.2 kg/5α width by JIS-L-1048 strip method.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway perspective view of a slit-type air soccer.
FIG. 2 is an explanatory diagram showing a typical process of the present invention, FIG. 3 is a partial front view of a case where a corona discharge device is provided between a yarn regulating device and a slit-type air sucker, and FIG. It is a partial front view which shows the example which provided the lower r corona discharge device of the slit type air soccer as a different aspect from the figure. Figure 7 Figure 5 Figure 4

Claims (1)

[Claims] 11+ Melt spinning of thermoplastic polymer ~ Roll stretching ~
In a method for manufacturing a nonwoven fabric by opening an air sucker, one air sucker with a width substantially equal to the width of the product is used as an air sucker for opening, and two air suckers each with a narrower width than the air sucker for opening are used in the stretching process. The yarn is drawn between the 10th roll group and the 20th roll group, which are made up of more than one roll group, and if necessary, a heat treatment device is provided between the rolls for heat treatment. A method for producing a nonwoven fabric, characterized in that a yarn regulating device is provided between the hook and the 20th loop group to determine the running position of the yarn, and the yarn is forcibly charged using a corona discharge device. (2) The method for producing a nonwoven fabric according to claim 1, wherein the corona discharge device is incorporated in the lower air channel of the slit-type air sucker. (A 31μ discharge device is installed above the slit-type air sucker and below the yarn regulating device, and the yarn regulating device and the corona discharge device are movable in the width direction of the nonwoven fabric). The method for producing a nonwoven fabric according to claim 1, wherein the width of the nonwoven fabric can be freely changed.