JPS6025524B2 - Melt blown spinneret block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for meltblown yarns of fiber-forming thermoplastic resins.

More specifically, it relates to a paper thread base block for threading a polymer into a high temperature jet gas stream through an orifice bored in a straight line along the paper thread medium direction of a heated paper thread base. The object of the present invention is to provide a high-grade thread nozzle block that is particularly effective when producing high-quality non-woven fabric mats. Regarding the melt blowing method, see Bouin A.
Buente (Industrial and Engineering Chemistry, Volume 4, No. 8, 1342-1 I 6
Page).

In addition, as a patent related to the paper thread method, Japanese Patent Publication No. 41-78
No. 83, JP-A No. 49-48921, Mochiseki No. 50-46
No. 972. For example, Hakama Kaisho 50-14
No. 6972 describes specific operating conditions for producing high-quality nonwoven mats by melt blowing. }It has been clearly shown that the selection of the correlation between the apparent viscosity of the polymer, the flow rate of the polymer, and the flow rate of the gas is important. In order to produce a wide medium nonwoven fabric mat, it is essential to make the temperature, viscosity, and flow rate of the polymer uniform in the direction of the paper yarn. However, the conventional type yarn device has a structure shown in FIGS. 1 and 2, in which the polymer supplied from the polymer inlet 5 flows inside the coat hanger-shaped manifold 6 in the direction of the paper yarn. After flowing, it flows into a narrow slit-shaped land 7 and is discharged from an orifice 8 at the tip of the land 7. The length of the polymer flow path in the die 1 from the polymer inlet 5 to the orifice 8 is as follows: The center and ends of the orifice array are significantly different.

Furthermore, differences occur in the heating history of the polymer received in the polymer flow path. Furthermore, the amount of discharge from the orifice 8 is directly influenced by the polymer flow in the land 7 immediately in front of the orifice 8, but in the conventional paper yarn device, the polymer flow path between the polymer inlet 5 and the orifice 8 is Since no resistor is included, the polymer drift within the land 7 directly affects the discharge amount from the orifice 8. Furthermore, since the conventional technology does not include a flow rate adjustment mechanism for the paper yarn direction, once the shape and dimensions of the manifold 6 and land 7 are set, the flow path characteristics of the die are determined, and the polymer type and viscosity change. In some cases, it may not be applicable. In the conventional technology, due to these drawbacks, viscosity unevenness and temperature unevenness of the polymer occur in the direction of the paper yarn, and even unevenness in the discharge amount occurs, which ultimately results in the spinning of a nonwoven fabric mat with paper yarn laminated. This results in unevenness in the area, polymer balls, and quality unevenness in the middle direction.
These drawbacks were particularly noticeable when the spinning process was widened. In order to solve these drawbacks, the present inventors conducted various studies and discovered the present invention.

In the present invention, a distribution pack is provided immediately before the edge thread nozzle, and the distribution pack is provided with a plurality of distribution grooves that widen toward the end along the direction during spinning, and a lotus hole is provided after the distribution grooves of the distribution pack. By providing grooves and further interposing a flow path resistor in the polymer flow path between the distribution pack and the spinneret, we have created a high-quality wide-medium nonwoven fabric mat with no unevenness or polymer balls in the yarn direction. The spinneret blocks necessary for the production of are provided. To explain the gist of the present invention in more detail, a distribution pack is provided, and a plurality of distribution grooves that widen toward the end in the direction of the paper yarn are provided in the distribution pack, so that the gear pump does not feed the distribution grooves. The polymers have similar flow path shapes between each distribution twill, and the flow path lengths are almost the same.

Furthermore, the history of heating and overturning received from said ryuchin is also the same. Therefore, it is possible to distribute the polymer evenly in the direction of the yarn, and furthermore, it is possible to uniformly flow the polymer and heat the polymer, and it is possible to uniformly distribute the polymer from the orifice of the paper yarn cap installed immediately after the distribution pack. It becomes possible to discharge the polymer. The polymer flow path of the weaving yarn cap is composed of a slit-shaped land extending in the direction of the paper yarn, and a row of orifices at the tip of the iron land. It is preferable that the divergent angle of the distribution groove be as small as possible, since this causes a difference in the length of the polymer flow path between the center and the ends of each distribution channel.

However, since the end widening part needs to be continuous in a straight line in the direction of the grade yarn, it is preferable in practice to set it to 20 degrees or more. Furthermore, if the diverging angle becomes too large, vortices will occur in the polymer flow within the distribution chamber, and in extreme cases, polymer retention will occur, so it is preferably set to 1200 or less. In addition, by arranging multiple gear pumps along the thread mid-way direction and providing a distribution pack corresponding to the gear pump, the polymer discharge amount for each gear pump can be adjusted. It becomes possible to adjust the polymer flow rate to

Furthermore, even if the type or viscosity of the polymer changes, the flow rate of the polymer can be adjusted without being affected by the flow path shape or dimensions of the distribution pack, expanding the range of applications of this yarn device. . The structure of the distribution pack may be divided into parts according to the number of gear pumps, or may be formed as a single unit.

Further, in order to make the effect of the present invention more effective, it is preferable to provide a lotus groove immediately after the distribution groove along the direction of the grain yarn, and further to interpose a flow path resistor immediately after the groove.

That is, the polymer supplied from the gear pump to the plurality of distribution grooves flows into the groove, and once communicated, the polymer pressure in the direction of the shark thread becomes uniform, and then it passes through the flow path resistor. After flowing into the land part of the shark thread cap and passing through the thread again, it is discharged from the orifice. Therefore, it becomes possible to discharge the polymer uniformly in the direction of the paper yarn.
The flow path resistor should be one that produces a uniform pressure loss through the polymer in the direction of the thread, and should be made of wire mesh, Akatsuki silk non-woven wire mesh, perforated plate, porous metal, or a combination of these. Good to use. Furthermore, by making the mesh of the flow path resistor smaller than the orifice diameter of the paper thread cap, it is possible to allow the supplied polymer to overflow the furnace, thereby preventing clogging of the orifice. The flow path resistor is not necessarily required within limited thread removal conditions, but by interposing the rare path resistor, stable spinning can be performed and the paper thread conditions can be expanded. In addition, by combining the distribution pack and the spinning nozzle in an Inryu formation, the pressure resistance of the distribution pack and the spinning nozzle against the polymer pressure is greatly increased, and furthermore, the deformation due to the stress of bolt tightening during assembly is increased. It can be prevented.

The fiber-forming thermoplastic resin in the present invention includes polyamide, polyester, polyethylene, polypropylene, polycarbonate, polyacrylic, polyvinyl, and copolymers or mixtures thereof.

The present invention is particularly effective for melt-blown paper yarns made of condensation polymers such as polyamide and polyester. Further, the term "polymer" as used in the present invention refers to the above-mentioned thermoplastic resin in a thermally molten state. Next, the embodiments of the present invention will be described in detail with reference to the drawings. Figures 3 and 4 show an example of a melt-blown paper yarn device equipped with a final blow spinneret block according to the present invention, and Figure 3 shows an example of a melt-blown paper yarn device in which a final blow spinneret block according to the present invention is attached. FIG. 4 is a vertical cross-sectional view along the direction during spinning.

To explain the flow of polymer using Figures 3 and 4,
First, a polymer is supplied to the polymer inlet 5 by an extruder, which is not shown in the drawings. It then flows into the suction port of the gear pump 13 through the polymer conduit 19 and the polymer inlet 20. These polymer conduit pipes 19 and polymer passage holes 20 are provided in a number corresponding to the number of gear pumps 13, and are designed so that their flow path lengths are the same. Next, it is divided into four equal parts in the gear pump 13, flows from the gear pump discharge port to the polymer conduction hole 21 bored in the spin block 12, and is further supplied to the paper thread nozzle block 141 via the packing 22. Ru. In Fig. 4, there are four polymer conduction holes 21 per gear pump, but in actual implementation, the number of polymer conduction holes 21 can be changed as desired by changing the number of discharge ports of the gear pump or branching through a wear plate. Can be set to Furthermore, since the polymer conduction holes 21 are diagonal holes, the flow path lengths differ slightly, but by changing the diameter of the polymer conduction holes, the residence time in each polymer conduction hole can be made equal, and the pressure loss can be reduced. It is also possible to make them equivalent. Therefore, polymer can be distributed and supplied to the plurality of polymer distribution inlets 24 provided in the distribution pack 23 under the same conditions. Figures 5 and 6
The figure is an enlarged view of the paper thread cap block 14 of the present invention,
FIG. 5 is a longitudinal cross-sectional view perpendicular to the direction of the yarn, and FIG. 6 is a longitudinal cross-sectional view taken along the direction of the spinning yarn.

The present invention comprises a distribution pack 23, a flow path resistor 27 provided immediately after it, and a spinneret 28 provided immediately after it, and a gas cover plate 2 is attached to the lower surface of the spinneret block of the present invention. It has become.

As described in FIGS. 3 and 4, the polymer supplied to the polymer distribution inlet 24 flows into a plurality of distribution grooves 25 provided in the distribution pack 23. The distribution groove 25 is a slit that widens toward the end, and the side that widens toward the end becomes a groove 26 that extends along the spinning direction. Multiple distribution grooves 2
It is preferable that the adjacent pitches P of 5 are equal pitches, and furthermore, it is preferable that the end divergence angles are all equal angles.
It is preferable to set the angle to an arbitrary angle within the range of o to 120o. This diverging angle is very important, and in the case of a viscous fluid such as a polymer, if the flow path is flared, eddies are likely to occur, so an angle of preferably within 60° produces good results. Immediately after the distribution pack 23 is a flow path resistor 2.
A spinneret 28 is attached with the land 7 interposed therebetween, and the spinneret 28 is provided with a land 7 having approximately the same closed area as the lotus groove 26 provided in the distribution pack 23. The land 7 has a narrow slit shape, and the depth is all constant in the direction of the weaving yarn, and furthermore, on the lower surface of the land 7, orifices for spinning are perforated at minute pitches in the direction of the paper yarn. . Therefore, the polymer integrated into the distribution pack 25 passes through the distribution groove 26, passes through the flow path resistor 27, flows into the land 7, and is discharged from the orifice 8. In this flow path system, the pressure loss of the polymer is dominated by the pressure loss passing through the flow separation resistor 27 and the orifice 8. Therefore, the pressure of the polymer is reduced to lagoon pressure within the passage groove 26 of the distribution pack 23, and further It will be changed to Hitoshi within Land 7. That is, in the prior art, in order to equalize the pressure of the polymer at the orifice inlet, the manifold and land were designed by performing complicated pressure loss calculations, but in the present invention, the flow path resistor 27
The problem was solved at once by intervening. Furthermore, the generation of vortices, which is a flow characteristic of the viscous fluid described above, is eliminated by arranging the distribution grooves 25 along the direction during spinning, so that the flow of the polymer becomes almost a parallel flow, and therefore the generation of vortices is eliminated. The distribution pack 23 connects the flow path resistor 27 to the paper thread cap 2.
8, is inserted into the paper thread cap 28 with a seal, and is tightened with a large number of vertical bolts 29. The flow path resistor 27 is made of a wire mesh, a bonded non-woven wire mesh, or a porous metal, and the outer periphery may be edged in a ring shape with copper, aluminum, stainless steel, steel, etc. Shape retention and even sealing of the polymer becomes easier.
Although the spinneret block 14 of the present invention has been described in detail above, supplementary explanation will be provided with reference to FIGS. 3 and 4 to further aid understanding. According to the above, suture extraction cap block 1
4 is inserted into the spin block 12 and a large number of bolts 30 are inserted into the spin block 12.
It can be installed from 1.

In the drawing, it is attached via a packing 22, but it may also be attached via a wear plate. A gas passage 34 is formed on the lower surfaces of the paper spinneret block 14 and the spin block 12 by attaching a conventional gas cover plate 2 with mounting bolts 32. At the tip of the plate 2, a slit 11, which is a gas injection port, is formed along the weaving yarn direction. The high temperature gas for melt blowing is supplied to a pair of gas headers 15 provided on the spin block 12.
The polymer is connected to the gas passage 34 from the gas inlet 9 at both ends of the orifice 8, and is injected from the spout 11 provided on both sides of the orifice 8 at a uniform high temperature and flow rate, thereby atomizing the polymer discharged from the orifice 8. , melt-blown paper yarn is made. Further, to heat the polymer, the heating body 3 in the jacket chamber 18 provided to cover the spin block 12 vaporizes the corpse heat medium 35, thereby heating the polymer conduit 19 and the spin block 12. Additionally, heat transfer from spin block 12 heats spinneret blocks 14 and the polymer flowing therethrough. Therefore, by uniformly heating the spin block 12 in the warp direction, the polymer can also be uniformly heated in the spinning direction.
To summarize the effects of the present invention, by making the flow path length of the polymer discharged from each orifice substantially the same for a large number of paper thread orifices, and by making the discharge pressure uniform, By making the history the same and furthermore making the polymer viscosity uniform, it became possible to melt blow a nonwoven fabric mat without ejection irregularities, polymer balls, or quality irregularities in the direction during thread removal.

Ma. By creating a yarn cap block with an arbitrary medium grade and combining multiple gear pumps, it becomes easy to widen the warp threads, and furthermore, since the discharge amount can be adjusted for each gear pump, it is possible to adjust the discharge amount in the direction during thread removal. It is now possible to adjust the basis weight for

[Brief Description of the Drawings] Figures 1 and 2 are an example of the final rut blow spinning method using the secondary kettle technology, and Figure 1 is a longitudinal cross-sectional view perpendicular to the direction during spinning;
FIG. 2 is a longitudinal sectional view taken during spinning. FIGS. 3 and 4 show melt tubes equipped with the paper thread cap flock of the present invention. - This is an example of a paper yarn device, and FIG. 3 is a longitudinal cross-sectional view perpendicular to the direction of the yarn in the yarn, and FIG. 4 is a longitudinal cross-sectional view along the direction of the yarn during spinning. FIGS. 5 and 6 show the suction cap of the present invention. FIG. 5 is a longitudinal sectional view perpendicular to the direction of the warp threads, and FIG. 6 is a longitudinal sectional view along the direction of the paper threads. 1...Die, 2...Gas cover plate, 3...Heating element, 4
... Heat insulator, 5... Polymer inlet, 6... Manifold, 7... Land, 8... Orifice, 9... Gas inlet,
11... Slit, 12... Spin block, 13... Gear pump, 14... Paper thread cap block, 15... Gas header, 16... Jacket, 18... Jacket chamber, 19.
・Polymer conduit, 20 ・Polymer conduction hole, 21・
...Polymer channel, 22...Packing, 23...Distribution pack, 24...Distribution inlet, 25...Distribution groove, 2
6... Lotus groove, 27... Polymer flow path resistor, 28
... spinneret, 29... bolt, 30... bolt, 31...
Gas passage, 35...heat transfer medium. Figure 1 Figure 2 Port 6 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a melt blow spinning mechanism equipped with means for supplying polymer to a spinneret 28 by a gear pump 13,
A distribution pack 23 is provided in the polymer passageway between the gear pump 13 and the spinneret 28, and the distribution pack 23 comprises:
A melt-blown spinneret block characterized by having a plurality of polymer distribution grooves 25 which are slit grooves that widen toward the end in the spinning width direction. 2. The melt-blown spinneret block according to claim 1, wherein the divergent angle of the distribution groove 25 is in the range of 20° to 120°. 3. The melt-blown spinneret block according to claim 1, wherein the distribution pack 23 and the spinneret 28 are combined by seal fitting. 4. In a melt blow spinning mechanism equipped with means for supplying polymer to a spinneret 28 by a gear pump 13,
A flow path resistor 27 is placed in the polymer passage just before the spinneret 28.
interposed, and furthermore, a distribution pack 23 is provided immediately before that,
A melt-blown spinneret block characterized in that the distribution pack 23 is provided with a plurality of distribution grooves 25 that widen towards the end in the spinning width direction, and a communication groove 26 that communicates the distribution grooves. 5. The melt-blown spinneret block according to claim 4, wherein the divergent angle of the distribution groove 25 is in the range of 20° to 120°. 6. The melt-blown spinneret block according to claim 4, wherein the distribution pack 23 and the spinneret 28 are combined by seal fitting. 7. The melt-blown spinneret block according to claim 4, wherein the flow path resistor 27 is made of a wire mesh, a sintered non-woven wire mesh, a porous plate, another porous metal, or a combination thereof.