JPH10298859A - Production of continuous filament nonwoven web - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process for stably manufacturing filament yarn nonwoven web that is well opened with a large static repulsion force by applying extremely high electric charge to continuous filament groups. SOLUTION: When nonwoven web is formed by stretching and thinning continuous filament group made of fiber-forming thermoplastic polymer by using a high-speed fluid flow stretching machine and the continuous filament group ejecting from the stretching machine are opened by the contact type fiber opener and collected and piled up on the piling face to form nonwoven web, the contact type fiber opener to be used here is equipped with the following elements (1) and (2): (1) continuous film 3 that runs, as it is contacting with the collision body 2 at its surface, and (2) the let-off motion 4 and the winding up means 5 for the continuous film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a long-fiber non-woven web, and more particularly, to a continuous filament group made of a fiber-forming thermoplastic polymer which is drawn and thinned using a high-speed fluid flow drawing device. Thereafter, the present invention relates to a method for applying a very high electric charge to the filament group to stably produce a long-fiber nonwoven web which is well opened with a large electrostatic repulsion for a long time.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a nonwoven web comprising long fibers of a fiber-forming thermoplastic polymer, a continuous filament group obtained by melt-spinning the polymer through a spinneret is provided downstream of the spinneret. The continuous filament group ejected from the traction device is drawn and thinned by using a high-speed fluid flow traction device arranged in a direction perpendicular to the web traveling direction corresponding to the spinneret. A so-called spunbond method is known in which the nonwoven web is formed by forming a nonwoven web by opening the fiber and then collecting and accumulating it on a movable collecting surface. In this method, before collecting and accumulating a group of continuous filaments ejected from a high-speed fluid flow traction device on a movable collection surface, usually,
The filament group is separated and opened into individual filament units through a process called a fiber opening process. For example, in order to obtain a long-fiber nonwoven fabric having a uniform basis weight, such fiber opening must be performed well. is required. In recent years, in the spun bonding method, various opening methods have been proposed in order to improve the opening property of a continuous filament group. For example, Japanese Patent Publication No. 54-28508 discloses a method in which a filament group is charged and opened by a corona discharge current generated by a high voltage generator. A method has been proposed in which a filament group is triboelectrically charged and spread using a collision plate made of a metal composed of two components of lead. However, in the former corona discharge method, it is difficult to apply a sufficient charge to the traveling filament group by the spun bond method in which the filament is pulled at a high speed.
Therefore, there is a limit in the improvement of the spreadability. In order to solve this problem, a method in which charging with corona discharge current is performed in two stages is conceivable, but in this case, a generator and other heavy equipment are required, raising costs and using high voltage. Is dangerous. In addition, the latter friction charging method has a problem that the surface of the collision plate wears due to friction between the collision plate and the traveling filament group. Not something. Further, as the surface wear increases with time, the traveling filament group is caught on the collision plate, and it is necessary to temporarily stop continuous operation, which is uneconomical.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and a continuous filament group made of a fiber-forming thermoplastic polymer is drawn and thinned using a high-speed fluid flow pulling device. It is intended to provide a method capable of stably producing a long-fiber non-woven web that has been opened well with a large electrostatic repulsion force by applying an extremely high charge to the web.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention has the following configuration as its gist. A continuous filament group melt-spun a fiber-forming thermoplastic polymer through a spinneret is provided with a high-speed fluid flow traction device disposed downstream of the spinneret corresponding to the spinneret and arranged in a direction perpendicular to the web traveling direction. The continuous filaments ejected from the traction device are spread by a contact-type opening device, and then collected and deposited on a movable collection surface to form a nonwoven web. In this case, a method for producing a long-fiber non-woven web, characterized in that a fiber-spreading device comprising the following components (1) and (2) is used as the contact-type fiber-spreading device. (1) Consisting of a collision body and a continuous film-like object running while contacting the collision body surface. (2) Equipped with a continuous film sending means and a winding means.

[0005]

Next, the present invention will be described in detail.
A feature of the method of the present invention is that a continuous filament group obtained by melt-spinning a fiber-forming thermoplastic polymer through a spinneret by a conventionally known spunbonding method corresponds to the spinneret downstream of the spinneret and the web progresses. Using a high-speed fluid flow pulling device arranged in a direction perpendicular to the direction, pulling and thinning the continuous filament group ejected from the pulling device by a contact-type opening device, and then moving and capturing the filament. When collecting and accumulating on the collecting surface to form a nonwoven web, the present invention is characterized in that the contact-type opening device uses the opening device including the components (1) and (2).

The filament-forming thermoplastic polymer for filaments to which the method of the present invention can be applied is, for example, a polyester polymer such as polyethylene terephthalate, polybutylene terephthalate or a polyester copolymerized with isophthalic acid; Polyamide-based polymers such as nylon 66 or low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and thermoplastic synthetic polymers such as polyolefin-based polymers such as polypropylene. The polymer blend or copolymer is not particularly limited as long as it can be melt-spun and has a fiber-forming property. In addition, these fiber-forming polymers include, for example, a fiber such as a matting agent, a pigment, a flame retardant, an antifoaming agent, an antioxidant, and an ultraviolet absorber as long as the effects of the present invention can be exhibited. Additives may be added.

[0007] In the method of the present invention, a continuous filament group melt-spun using a high-speed fluid flow pulling device is pulled or pulled.
Although it is narrowed, as a method of arranging the towing device that can be adopted,
In addition to the method of arranging a plurality of types having circular openings, for example, a method of installing an integrated type having a rectangular opening, such as a method of installing an integrated type having a rectangular opening, is commonly used in a so-called spunbond method. The method is not particularly limited as long as the method is used.

The contact-type opening device employed in the method of the present invention is an opening device comprising the above-mentioned components (1) and (2). In the method of the present invention, the continuous film-like material in the fiber opening device is a material that is triboelectrically charged and spread by colliding the continuous filament group ejected from the traction device with the continuous film group, and is composed of an organic compound. Is what is done. Such organic compounds include, for example, homopolyester-based to copolyester-based polymers, homopolyamide-based to copolyamide-based polymers, homopolyolefin-based to copolymerized polyolefin-based polymers, and the like. Not limited
The remaining thermoplastic synthetic polymer may be used.

Here, what is important for the film-like material is that its constituent polymer is selected depending on the positional relationship on the charging line with the fiber-forming thermoplastic polymer constituting the continuous filament group. The point that must be done. Generally, when two substances are brought into contact, one is charged to the positive electrode and the other is charged to the negative electrode. At this time, which is charged to the positive electrode and which is charged to the negative electrode is unique to each substance. The term “charging sequence” as used herein refers to a material in which a substance that is most easily charged to the positive electrode and a material that is most easily charged to the negative electrode are arranged in a line, and the charge generated when two substances are brought into contact is charged. It is determined by the positional relationship between the two substances in the row.For example, a substance that has a large electric charge when contacting substances that are in a distant positional relation in a charged row, and has a close positional relation. It is known that the electric charge generated in the case of each other becomes small. In the method of the present invention, an organic compound having a distant positional relationship on the charging line with respect to the fiber-forming thermoplastic polymer constituting the continuous filament group may be selected as a constituent material of the film. For example, when the continuous filament is mainly made of a polyester-based polymer such as polyethylene terephthalate, a polymer such as nylon 6, polytetrafluoroethylene, polyimide, or polyvinyl chloride is preferably used. In this case, the negative electrode is charged, and in the case of polytetrafluoroethylene, polyimide, and polyvinyl chloride, the positive electrode is charged. When the continuous filament is mainly composed of a polyamide-based polymer such as nylon 6, a polymer such as polyethylene, polypropylene, polyethylene terephthalate, polytetrafluoroethylene, polyimide, or polyvinyl chloride is preferably used. The group will be charged to the positive electrode. Further, when the continuous filament is mainly composed of a polyolefin-based polymer such as polyethylene, a polymer such as nylon 6, polytetrafluoroethylene, polyimide, or polyvinyl chloride is preferably used. In this case, the negative electrode is charged, and in the case of polytetrafluoroethylene, polyimide, or polyvinyl chloride, the positive electrode is charged.

[0010] In the method of the present invention, the impingement body in the fiber opening device is a base on which a continuous film-like material is made to travel while being in contact with the surface thereof, and may have a plate-like surface form or Even if it has a curved surface form such as an arc shape, any form may be used as long as the continuous film-like material can be favorably run on the surface. The important thing about this colliding body is that it is preferable to select a range of 120 to 160 ° as an angle formed between the colliding body and the filament group at a position where the running continuous filament group collides with the colliding body. is there. This angle is 1
If it exceeds 60 °, the contact angle between the continuous filament group and the colliding body is too small, and the amount of charge applied to the filament is reduced, that is, the electrostatic repulsion force is reduced and the spreadability is reduced. If this angle is less than 120 °, the contact angle between the continuous filament group and the colliding body is too large, and the amount of charge applied to the filament increases, but the traveling speed of the filament group traveling on the colliding body is significantly reduced. As a result, the filament scatters on the collision body, which is not preferable.

[0011] In the method of the present invention, the means for feeding and winding the continuous film-like material in the fiber opening device includes:
This is for constantly updating the film-like material existing on the surface of the collision body. As the sending means and the winding means,
For example, general means such as an electrically driven roll device may be employed. The running direction of the continuous film-like object may be either the same direction or the opposite direction to the running direction of the continuous film group, but when the reverse direction is set, the relative speed of the continuous film-like object to the continuous film group increases. This is advantageous in renewing the film on the collision object.

Next, the present invention will be described in more detail with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a schematic view showing an embodiment for explaining the method of the present invention, in which 1 is a continuous material made of a thermoplastic polymer melt-spun from a spinneret (not shown). The filament group 2 is a collision body in the fiber opening device for opening the continuous filament group 1, and 3 is a collision body 2
The continuous film-like material 4 running above is a delivery roll device for the continuous film-like material 3, and 5 is a winding roll device for the continuous film-like material 3. In the method of the present invention, a plurality of continuous filament groups 1 made of a thermoplastic polymer melt-spun from a spinneret are provided using a high-speed fluid flow traction device disposed downstream of the spinneret and corresponding to the spinneret. The continuous filament group 1 ejected from the traction device is caused to collide with the continuous film-like material 3 running while contacting the collision body 2 of the contact-type opening device with the traction device. An extremely high charge is applied to the filament group 1 to obtain a long-fiber nonwoven web which is well opened with a large electrostatic repulsion. At this time, the continuous film material 3 is constantly updated on the collision body 2 by the delivery roll device 4 and the take-up roll device 5, so that the surface of the collision body does not change with time, and the continuous operation for a long time is performed. In this case, the filament opening of the filament group 1 can be kept constant at all times, and the filament group 1 is caught by the colliding body due to an increase in the surface wear of the colliding body over time as in the conventional method, and the continuous operation is performed. There is no need to suspend the operation.

In the method of the present invention, such a contact-type opening device is employed. However, the installation of this device is not limited to one stage, and two stages may be installed in the vertical direction as needed. Is also good. When two stages are installed in the vertical direction, it is preferable that the devices in each stage are installed so as to be opposed to each other so that electric charges can be applied to almost the entire circumference of the traveling filament.

In the method of the present invention, the continuous filament group that has been melt-spun is drawn and thinned by using a high-speed fluid flow drawing device corresponding to the spinneret and arranged in a direction perpendicular to the web traveling direction. As the high-speed fluid flow, an inert gas such as nitrogen may be used in addition to air, but it is preferable to use air from the viewpoint of economy and working environment.

[0015]

The method of the present invention relates to a conventionally known spunbonding method, in which a continuous filament group obtained by melt-spinning a fiber-forming thermoplastic polymer through a spinneret is provided downstream of the spinneret. And a high-speed fluid flow pulling device arranged in a direction perpendicular to the web advancing direction to pull and narrow the continuous filament group ejected from the pulling device by a contact opening device. Then, when collecting and accumulating on the movable collecting surface to form a nonwoven web, the contact-type opening device uses the opening device including the components (1) and (2) described above. Things. The method of the present invention uses a specific opening device as described above,
The continuous filament group is made to collide with the continuous film-like object running on the collision body of the contact-type opening device while being in contact therewith, and by this contact friction, an extremely high charge is applied to the filament group so that the filament is spread well. In this case, the continuous film-like material is constantly updated on the impacting body by the delivery roll device and the winding roll device. no change. Therefore, even in the case of long-time continuous operation, the filament opening of the filament group can be constantly maintained constant.

[0016]

Next, the present invention will be specifically described based on examples. The measurement and evaluation of various characteristics in the examples were performed by the following methods. Melting point of polymer (° C.): The melting point (° C.) is the temperature at which the maximum value of the melting endothermic peak measured at a heating rate of 20 ° C./min using a differential scanning calorimeter DSC-7 manufactured by Perkin Elmer Co., Ltd. did. Intrinsic viscosity of polyester: A sample solution of 0.5 g / 10 in an equal weight mixed solution of phenol and ethane tetrachloride as a solvent
It was measured by a conventional method under the conditions of 0 cc and a temperature of 20 ° C. Relative viscosity of nylon: Measured according to the method described in JIS K6810. That is, the measurement was performed under the conditions of a sample concentration of 0.1 g / 100 cc and a temperature of ° C. using 98% by weight concentrated sulfuric acid as a solvent. Melt flow rate value of polypropylene: ASTM D
It was measured according to the method described in 1238 (L). The charge amount of the filament (μC / m ² ): The charge amount of the filament sample was measured using an electrostatic charge meter KQ-431B manufactured by Kasuga Electric Co., Ltd., and the charge amount was obtained per unit area (m ² ). The value was defined as the charge amount of the filament (μC / m ² ). The measurement was performed twice immediately after the traveling filament group came into contact with the colliding body, and twice after the elapse of 24 hours, and the change with time of the charge amount was evaluated as a charge amount change rate (%). Charge amount change rate (%) = [(Q ₁ −Q ₂ ) / Q ₁ ] × 10
0 [Q ₁ : charge amount (μC / m ² ) immediately after contact with the collision object;
Q ₂ : Charging amount after 24 hours (μC / m ² )] Evaluation of opening property: The opening degree of the filament group was good when the charging rate change rate was 90% or more, and the charging rate change rate was 90. % Was evaluated as poor. Filament trapping phenomenon: The presence or absence of the trapping phenomenon of the traveling filament group with respect to the collision plate was visually observed.

Example 1 A chip of a polyethylene terephthalate polymer having a melting point of 260 ° C. and an intrinsic viscosity of 0.68 was melted at a temperature of 290 ° C. using a conventional melt spinning apparatus, and then a single hole discharge amount of a spinneret was adjusted to 1 The spun filament group was cooled using a cooling device, and the spun filament group was continuously fed to the downstream side of the spinneret by an air scater corresponding to the spinneret at a speed of 4800 m / min. / Min.
After taking-up and opening with a contact-type opening device, the fibers were continuously collected and deposited on a movable collecting surface to prepare a nonwoven web composed of a continuous filament having a single-filament fineness of 3.0 denier.
At this time, as a contact-type opening device, a collision body (an angle θ formed between the filament group and the collision body is 145 °) having a flat surface shape as shown in FIG. A device consisting of a continuous film of nylon 6 running while contacting was adopted. In this fiber opening device, the feed roll device and the take-up roll device are driven to continuously run a continuous film of nylon 6 at a speed of 0.6 m / min. Updated the film. The results of the evaluation of the amount of charge and the like of the obtained filament were as follows. Note Charge amount immediately after contact with the colliding body: 51 μC / m ² Charge amount after 24 hours: 51 μC / m ² Charge amount change rate: 100% Spreadability: Good Filament trapping phenomenon: None

Example 2 A nylon 6 polymer chip having a melting point of 225 ° C. and a relative viscosity of 2.65 was heated to 260 ° C. using a conventional melt spinning apparatus.
After spinning, the spinning nozzle is spun at a single hole discharge rate of 1.50 g / min, the spun filament group is cooled using a cooling device, and the spun filament group is continuously placed downstream of the spinneret. After being pulled, stretched and taken off at a speed of 4500 m / min by an air sucker arranged corresponding to the spinneret, and opened by a contact opening device, it is continuously collected and deposited on a movable collection surface. A nonwoven web composed of a continuous filament having a single yarn fineness of 3.0 denier was prepared. At this time, the filament group was opened in the same manner as in Example 1 except that a continuous film of polyethylene terephthalate was used instead of the continuous film of nylon 6 in the contact opening device. The results such as the charge amount evaluation of the obtained filament are as follows.
It was as follows. Note Charge amount immediately after contact with the colliding body: 53 μC / m ² Charge amount after 24 hours: 52 μC / m ² Charge amount change rate: 98% Opening property: Good Filament trapping phenomenon: None

Example 3 Melting point: 165 ° C., melt flow rate: 30 g / 10
Is melted at a temperature of 240 ° C. using a conventional melt spinning apparatus, and then spun at a single hole discharge rate of the spinneret of 1.33 g / min, and the spun filament group is cooled using a cooling device. The spinning filament group is continuously pulled down at a speed of 4000 m / min by an air sucker disposed downstream of the spinneret corresponding to the spinneret.
After drawing and drawing and opening with a contact-type opening device, they are continuously collected and deposited on a movable collecting surface, and the single yarn fineness is 3.0.
A nonwoven web consisting of a denier continuous filament was made. At this time, the filament group was opened in the same manner as in Example 1 except that a continuous film of polytetrafluoroethylene was used instead of the continuous film of nylon 6 in the contact opening device. The results of the evaluation of the amount of charge and the like of the obtained filament were as follows. Note Charge amount immediately after contact with the colliding body: 45 μC / m ² Charge amount after 24 hours: 45 μC / m ² Charge amount change rate: 100% Spreadability: Good Filament trapping phenomenon: None

Comparative Example 1 A filament was prepared in the same manner as in Example 1 except that an apparatus consisting only of a copper metal collision body having a flat surface as shown in FIG. The group was opened. The results of the evaluation of the amount of charge and the like of the obtained filament were as follows. Charge amount immediately after serial impact body contact: 30 .mu.C / m ² after 24 hours after charging amount: 10 [mu] C / m ² charge change rate: 33% openability: defective filament caught phenomenon: There

As is clear from the above results, in Examples 1 to 3 employing the fiber opening device satisfying the constitutional requirements of the present invention, when the continuous filament group is opened to produce a nonwoven web, Since the continuous film of the apparatus was constantly updated on the colliding body, there was no change with time on the colliding body surface, and as is clear from the results of the filament charge amount immediately after contact with the colliding body of the filament group and after 24 hours. In addition, even when the continuous operation was performed for a long time, the filament opening of the filament group could always be kept constant. On the other hand, in Comparative Example 1 in which the fiber opening device that satisfies the constituent requirements of the present invention was not adopted, as is clear from the above results, the surface of the collision body of the fiber opening device changed with time, and the filament group As is clear from the results of the filament charge amount immediately after contact with the colliding body and after 24 hours, the filament opening property of the filament group decreased over time.

[0022]

According to the method for producing a nonwoven web comprising a continuous filament of the present invention, a conventionally known spunbond method, that is, a continuous filament group obtained by melt-spinning a fiber-forming thermoplastic polymer is drawn and thinned. When the fiber is opened by a contact-type opening device and then collected and deposited on a movable collecting surface to form a nonwoven web, the above-mentioned components (1) and (2) are used as the contact-type opening device. According to this method, an extremely high charge is applied to the filament group to stabilize a long fiber nonwoven web that has been well opened with a large electrostatic repulsion for a long time. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment for explaining a fiber opening device part in a production method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 continuous filament group 2 colliding body in opening device 3 continuous film-like object in opening device 4 delivery roll device 5 winding roll device θ Angle between continuous filament group and colliding object

Claims (4)

[Claims] A continuous filament group obtained by melt-spinning a fiber-forming thermoplastic polymer through a spinneret is provided at a high speed provided downstream of the spinneret in a direction corresponding to the spinneret and perpendicular to the web traveling direction. The continuous filaments ejected from the traction device are spread by a contact-type opening device, and then collected and deposited on a movable collection surface. When forming a woven web, a method for producing a long-fiber non-woven web, comprising using an opening apparatus comprising the following components (1) and (2) as the contact-type opening apparatus. (1) Consisting of a collision body and a continuous film-like object running while contacting the collision body surface. (2) Equipped with a continuous film sending means and a winding means. 2. The method for producing a long-fiber nonwoven web according to claim 1, wherein the impactor has a flat surface morphology. 3. The method for producing a long-fiber nonwoven web according to claim 1, wherein the impactor has a curved surface morphology. 4. The method for producing a long-fiber nonwoven web according to claim 1, wherein the continuous film-like material is made of an organic compound.