JP3223658B2 - Composite melt blown sheet, method for producing the same, and filter unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite meltblown sheet which is a filter medium suitable for the field of filters having a strong and dense structure, a method for producing the same, and a filter unit.

[0002]

2. Description of the Related Art In general, melt-blown nonwoven fabrics are formed by forming a web by thinning a thermoplastic resin into a fibrous shape by hot-air jetting, and can obtain fine fibers of several tens μm to several μm or less. Used as a suitable substrate. In particular, those that have been electret processed
High collection performance is obtained, and it is widely used in the field of filters. However, the melt blown nonwoven fabric is generally a non-stretched yarn and a very fine fiber, so the product strength is weaker than that of a general nonwoven fabric, and is a soft nonwoven fabric without a stiffness. As a filter medium, it was very difficult to use it alone.
Therefore, they are often used as composites in combination with staples, pulp, long and short nonwoven fabrics, woven or knitted fabrics or nets. Regarding the technique of manufacturing a composite melt-blown non-woven fabric by laminating and collecting the melt-blown non-woven fabric, a method of supplying another member to the collection surface of the melt-blown fibers as described in JP-A-53-105573, or a method of combining and integrating, Japanese Patent Application Laid-Open No. 62-289661 proposes a method of compounding melt-blown nonwoven fabrics.

[0003]

However, these composite melt blown sheets according to the prior art have a fatal drawback in that the sheet strength is low and the sheet is easily peeled off at the composite interface.

[0004] In view of the drawbacks of the prior art, the present invention provides
An object of the present invention is to provide a composite melt-blow sheet having a strong and stiff structure and a high sheet strength, which is hard to peel off at the interface, and stably produce such a sheet. Further, according to the method for producing a composite melt blown sheet of the present invention, an electret sheet having a high charge can be composited while maintaining the charge, and as a result, a high pressure drop having a low pressure loss and a high trapping performance can be obtained. A performance filter can be provided.

[0005]

In order to achieve the above-mentioned object, the present invention employs the following configuration. That is, the composite melt blown sheet of the present invention has a fiber layer A
And a laminated sheet in which a melt-blown fiber layer B having an average fiber diameter of 5 μ or more is bonded with shots as an adhesive , and the rigidity of the sheet by a 45-degree cantilever method according to JIS L 1096 is 15 cm or more. The method for producing a composite melt-blown sheet according to the present invention is characterized in that a fiber layer B made of melt-blown fibers is laminated on a fiber layer A, collected, and integrated to form a composite melt-blown sheet. In the method for producing a sheet, the fiber
The layer A and the meltblown fiber layer B form a shot with an adhesive.
As a condition for forming the melt-blown fiber layer B, when extruding the molten polymer from the pores of the die, the tip of the die is projected at 0.2 to 0.7 mm and sprayed. It is characterized by melt-blowing under the condition of disturbing the air flow at the tip of the hot air mouthpiece, and further, when laminating, collecting and integrating fiber layers B composed of melt-blown fibers to produce a composite melt-blown sheet. , The fiber
The fiber layer A and the melt-blown fiber layer B bond the shot with an adhesive.
As a resin forming the fiber layer B,
Ri Monodea characterized by meltblowing poor resin blend resins compatible with each other, also, further, fiber
On the fiber layer A, a fiber layer B made of melt blown fiber is laminated.
Layer, collect and integrate to produce composite meltblown sheet
The fiber layer A is electret-processed.
And a fiber layer at the time of laminating the fiber layer B.
A has a surface temperature of 50 ° C. or less than the melting point of the fiber layer A.
It is characterized in that it is held every time. Further, the filter unit of the present invention is characterized in that a filter portion is constituted by the above composite melt blow sheet.

[0006]

The present invention relates to a composite melt blow sheet,
To investigate that can improve significantly shaping property to constitute a sheet having a particular stiffness the laminated sheet of fiber layer A and the fiber layer B, furthermore, also such sheet characteristically occurs melt-blown The present inventors have focused on the polymer discharge phenomenon and found that it can be obtained very simply and easily by using this phenomenon skillfully.

That is, the present invention utilizes a shot (polymer particle) generated depending on conditions in a fabric making method by melt blowing. In the present invention, the above-described excellent effects are achieved for the first time by positively generating the shots and using the shots as an adhesive.

When a composite substrate is to be obtained by spraying a melt blown fiber onto a fiber layer, Japanese Patent Application Laid-Open No. Sho 53-10557
3. As described in JP-A-2-289161, it is general to supply the melt-blown fiber to the fiber layer before the melt-blown fiber is solidified, and to integrate the melt-blown fiber with another base material. In this case, it is important not only to simply laminate, but also to have a low pressure loss of the laminate, a dust holding property as a filter, a fold processing when forming a filter, and a good shaping property after the folding processing. .

In order to provide a composite melt-blow sheet having such performance, the fiber layer A is preferably provided with at least 5 μm
More preferably, by laminating, collecting and integrating a fiber layer B composed of a melt blown fiber having an average fiber diameter of 10 μ or more, it is possible to provide a crimping process and a product excellent in shapeability after the folding process. be able to. When the average fiber diameter of the fiber layer B is 5 μm or less, the fiber itself is weak and the self-fusion force is small, and the effect of the beam formed at the intersection of the fibers may be reduced.

In order to improve the shape of the folded sheet and the formability after the folding, a laminated sheet according to JIS L1096 is used.
The degree of softness by the 5 degree cantilever method is 15 cm or more, preferably 20 cm or more. This softness is 15cm
The following cases are not preferred because they are too soft, have poor shape retention, are inferior in process passability, and tend to be deformed by the resistance of passing air during use as a filter.

In order to make the rigidity of such a laminated sheet 15 cm or more, the basis weight of the fiber layer B made of melt blown fiber is preferably 40 g / m 2 or more, more preferably 60 g / m 2 or more.
g / m2 or more is good. The basis weight of the fiber layer B is 40 g /
If it is less than m2, the effect of the beams formed at the intersections of the fibers will be weak, resulting in a soft fiber layer, which is not preferable.

The fiber layer B composed of melt blown fibers has a thickness of 2
More than two layers may be laminated, and it is also a preferable method to form a configuration in which the fiber layer A is laminated in a sandwich shape. Composite meltblown sheet for filter, less than 5 [mu] to the substrate using a meltblown sheets electret processed having a fiber diameter, this is laminated collecting meltblown fibers or a fiber diameter of 5 [mu], moreover, per width 3 cm <br /> Peel strength of 5 g or more (hereinafter, 5 g / 3 cm or more )
Expressed) and then, JIS L 10 further meltblown fibers
The rigidity by the 45-degree cantilever method according to 96 is 15
By setting it to cm or more, it is possible to provide a composite melt-blow sheet that can be easily folded in the filter unit molding.

A basic apparatus and a method for producing a melt blown sheet are disclosed in Industrial and Engineering Chemistry, Vol. 48, No. 8, 1956. Is melted, extruded from the mouth of a die, injected with high-temperature hot air, or the like, and collected.

In order to fabricate the fiber layer B composed of the melt blown fibers having an average fiber diameter of 5 μ or more, the conditions for the melt blow fabric are preferably such that the resin viscosity is 300 ps.
As described above, it is preferable to satisfy at least one condition of the air pressure of 0.5 kg / cm ² or less. When these conditions are removed, that is, the resin viscosity is 300 ps or less, and the air pressure is 0.5
When it is not less than Kg / cm ^2, it is difficult to fabricate a melt-blown fiber with an average fiber diameter of not less than 5 μm. Economically, it is preferable to set the air pressure to 0.5 kg / cm ² or less,
When the content is 0.05 kg / cm ² or less, it is difficult to provide a uniform melt blown sheet due to the turbulence of the external air flow.

In the present invention, a shot is positively generated to obtain a melt blown sheet containing the shot. The method of generating such a shot is to melt a high-molecular polymer having a fiber forming ability, Extrusion from the mouth of the mouthpiece, disrupting the balance of hot air when spraying with high-temperature hot air, etc., and disturbing the airflow at the tip of the mouthpiece, or blending a resin with poor compatibility with a material having fiber forming ability, or By blending resins of the same kind having different melt viscosities, or by employing a method in which these are combined, the fiber layer B can be a shot-containing melt-blown sheet.

As a method of disturbing the air flow at the tip of the die, for example, in a basic apparatus and method for producing melt blown fibers, in the case of a stick-out die structure in which the tip of the die comes out of an air slit hole, the tip of the die is projected. Of about 0.2 to 0.7 mm can be adopted.

The above-mentioned poorly compatible resin is different from the resin having a different solubility parameter, for example, in the case of polypropylene, by slightly blending a polyester, polyamide, or a modified product or copolymer thereof. Alternatively, in the case of the same type of resin, for example, polypropylene, a resin obtained by blending resins having melt indexes different by about 10 times or more is used.

The shot is preferably 100 cm in view of improving the integration with the fiber layer A and the moldability of the laminate.
^The number per ^{2 is} 3 to 30, more preferably 5 to 10. However, such a shot is 100cm
^If it is 50 or more per ² , the peel strength will be improved, but it is not preferable for use in a filter because it causes an increase in pressure loss and a decrease in dust holdability. Such shots are preferably made of polymer particles of about 1 to 3 mm, particularly preferably about 1 ± 0.5 mm. Larger shots cause problems such as an increase in pressure loss.

When it is desired to impart a high-performance filter function to the composite melt blown sheet of the present invention, a fiber layer A which has been subjected to electret processing is used. In this case, when the fiber layer B composed of melt blown fibers is laminated. The surface temperature of the fiber layer A is preferably kept at 50 ° C. or lower than the melting point of the fiber layer A. That is, although it depends on the charge trapping state of the electret fiber layer A, it has been found that the charge is easily released as the temperature rises from about 50 ° C. lower than the melting point of the fiber layer A. For example, in the case of an electret processed product made of a polypropylene material having a melting point of 165 ° C., when the temperature is higher than 115 ° C., the release of electric charge becomes severe. Therefore, in the case of the fiber layer A made of the material, the surface temperature is set to 115 ° C. It is kept below.

As a method of controlling the surface temperature of the electret-processed fiber layer A, the jet fiber diameter is determined by the melt blown fiber production conditions, that is, the viscosity, temperature, discharge amount, temperature of hot jet air, flow rate, and collection of the molten resin. It is preferable to control with.

When adjusting the surface temperature of the fiber layer A at the ambient temperature, it is preferable not to set the ambient conditions at a very low temperature. Conventionally, when fabricating melt blown sheets,
It is said that when the ambient temperature is lowered, a soft sheet with a beautiful sheet surface can be obtained. However, in the case of the present invention, if the ambient temperature is too low, for example, under 40 ° C.
It should be noted that even shot-thick (5 μm or more) melt-blown fibers tend to be cooled too much and lose their adhesiveness to the fiber layer A.

In general, even if electret processing is performed on a composite sheet, the filter function cannot be improved so much. This is a phenomenon that occurs because the basis weight of the composite sheet is too large. That is, even if the composite sheet is electret-processed, charge cannot be injected into the sheet. Therefore, in the present invention, first, charge injection is performed in the state of a single sheet having a small basis weight before compounding, and this is used as the fiber layer A. By forming a composite melt-blown sheet using the fiber layer A and then injecting charges into the fiber layer B, a material having a high electret effect and a high-performance filter function can be provided. As a method of such electret processing, a normal processing method such as a method of performing corona discharge processing in a sheet shape or a method of performing corona discharge processing in a process of collecting and spinning fibers is used.

As the fiber layer A, any sheet can be used. For example, melt blown nonwoven fabric,
Sheets such as spunbonded nonwoven fabrics and short-fiber nonwoven fabrics, and electret processed products of these sheets can be used. Among these sheets, a polyolefin or a copolymer thereof is preferably used from the viewpoint of electret workability and the like.

The fiber layer B is made of a material having a fiber-forming ability such as polyamide, polyester, polyolefin and copolymers thereof. Is preferably used.

[0025]

EXAMPLES Hereinafter, the content of the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples and the processing.

In the following description, the fineness is shown by a median value obtained by measuring the diameter of 150 fibers by enlarging the surface of the fiber layer by 500 times with an electron microscope.

Regarding the number of shots, the melt-blown fibers of the fiber layer B were collected in a single layer, and the shots were transferred to the sheet with transmitted light. Measure the number per ² pieces.

Example 1 As a fiber layer A, a needle-punched product of a polypropylene spunbonded nonwoven fabric was used, the average fiber diameter of which was about 30 μm, and the basis weight was 100.
g / m ² is supplied to a melt blown nonwoven fabric manufacturing apparatus, and melt blown fibers are laminated and collected on the fiber layer A. That is, a polypropylene resin having a melt index of 100 is melted at 310 ° C., and a hole pitch is 1.0 mm, a hole diameter is 0.3 mm,
The resin is extruded at a discharge rate of 1 kg / min from a die arranged in a row of 1,300 holes, and is injected together with hot air at 310 ° C. and a pressure of 0.2 kg / cm ² , thereby injecting melt blown fibers having an average fiber diameter of 23 μm. A rotary drum collecting device composed of a 50-mesh wire mesh surface provided with a suction device was installed at a position 20 cm below the die, the electret-processed base material was supplied to the drum surface, and the basis weight of the injected melt blown fibers was 100 g. / M
^The collection speed was adjusted to be ² . The surface temperature of the melt blown fiber layer B was 95 ° C. by an infrared thermometer.

The filter performance of the obtained electret base material was 27% at an average collection efficiency of a wind speed of 3.0 m / min and a particle diameter of 0.3 μm.

The fiber layer A and the melt blown fiber layer B are
The bond strength is strong at the cut portion, and the peel strength between the fiber layer A and the melt blown fiber layer B was measured on a 3 cm-wide sample with a constant-speed elongation type tensile tester, and the result was 10 g / 3 cm, JIS L 1
Rigidity by the 45-degree cantilever method according to 096 is 3
It was 0 cm.

The composite meltblown nonwoven fabric was electret processed by passing the corona discharge region at an applied voltage of 40 KV at a speed of 30 m / min at an interval of 7 cm between the applied electrode and the earth electrode. The filter performance of the obtained electret base material was 6 m at an average collection efficiency of 3.0 m / min in wind speed and 0.3 μm in particle diameter.
5%.

When processed into a filter unit, the former was used as a pre-filter, the latter was used as a medium-performance filter, and the dust-holding property was good, with no crimping workability, deformation due to wind speed during use, and delamination.

Example 2 The average fiber diameter obtained by a general melt blow method was about 3 μm,
A melt-blown non-woven fabric made of polypropylene having a basis weight of 20 g / m ² was passed through a corona discharge region with an applied voltage of 40 KV at a speed of 30 m / min to perform electret processing with the distance between the applied electrode and the ground electrode being 7 cm. The filter performance of the obtained electret sheet was 1.5 m / min.
The average collection efficiency at a particle diameter of 0.3 μm was 85%.

Next, the electret-processed sheet is supplied to a melt-blown nonwoven fabric manufacturing apparatus, and melt-blown fibers are stacked and collected on the substrate. That is, a polypropylene resin having a melt index of 100 is melted at 310 ° C., and extruded at a discharge rate of 1 kg / min from a die arranged in a row with a hole pitch of 1.0 mm, a hole diameter of 0.3 mm, and a number of holes of 1,300 at 310 ° C. Injection is performed together with hot air having a pressure of 0.3 kg / cm ² to melt-blown fibers having an average fiber diameter of 15 μm. A rotary drum collecting device composed of a 50-mesh wire mesh surface provided with a suction device at a position 20 cm below the base is installed, and the electret processed sheet is supplied to the drum surface,
The collecting speed was adjusted so that the basis weight of the jetted melt blown fibers was 100 g / m ² . The surface temperature of the electret-processed sheet was 91 ° C. by an infrared thermometer.

Electret processed sheet and melt blow
The fiber has a strong bond at the shot portion, and the peel strength of the obtained composite meltblown nonwoven fabric electret-processed sheet and the meltblown fiber nonwoven fabric was measured with a constant-rate elongation-type tensile tester on a 3 cm-wide sample. JIS L
The bending resistance by the 45-degree cantilever method according to 1096 was 25 cm. The filter performance of the obtained composite meltblown nonwoven veneer was measured under the above measurement conditions under an average collection efficiency of 84.
% And no decrease in the electret effect. When processed into a filter unit, the foldability was good, and no deformation or delamination due to wind speed during use was good.

Example 3 An average fiber diameter of about 1.5 obtained by a general melt blow method
μ, a melt-blown non-woven fabric made of polypropylene with a basis weight of 15 g / m ² , and the distance between the applied electrode and the earth electrode was 7
cm, and passed through a corona discharge region with an applied voltage of 40 KV at a speed of 30 m / min to perform electret processing. The filter performance of the obtained electret sheet was 1.5 m / wind.
The average collection efficiency at a particle size of 0.3 μm was 92%.

Next, the electret-processed sheet is supplied to a melt-blown nonwoven fabric manufacturing apparatus, and melt-blown fibers are stacked and collected on the sheet. That is, a polypropylene resin having a melt index of 100 was blended with 5% by weight of a polypropylene resin having a melt index of 7 to obtain 3
Melted at 10 ° C., extruded at a discharge rate of 1 kg / min from a die arranged in a row with a hole pitch of 1.0 mm, a hole diameter of 0.3 mm, and a number of holes of 1300, and heated at 310 ° C. under a pressure of 0.3 kg / cm ² . And melt-blown fibers having an average fiber diameter of 15 μm. A suction device is provided at a position 35 cm below the base 5
A rotating drum collecting device composed of a 0-mesh wire mesh surface was installed, and the electret-processed sheet was supplied to the drum surface, and the basis weight of the injected melt blown fibers was 80 g / m ^2.
The collection speed was adjusted so that The surface temperature of the electret-processed sheet was 70 ° C. by an infrared thermometer.

When the melt-blown fibers having an average fiber diameter of 15 μm are collected in a single layer, the number of shots is 5 per 100 cm 2.
An electret-processed sheet of the composite melt-blown nonwoven fabric obtained, which has a strong bond at the shot portion with a melt-blown nonwoven fabric made of polypropylene having an average fiber diameter of about 1.5 μm and a basis weight of 15 g / m 2 supplied to the laminate. The peel strength of the melt blown fiber non-woven fabric was 7 g / 3 cm, as measured by a constant speed elongation type tensile tester on a 3 cm wide sample.
The bending resistance according to the 45-degree cantilever method according to JIS L 1096 was 22 cm. The filter performance of the composite meltblown nonwoven veneer obtained was 90% average collection efficiency under the above measurement conditions, and there was no decrease in electret effect.
When processed into a filter unit, the foldability was good, and no deformation or delamination due to wind speed during use was good.

Example 4, Comparative Example 1 An average fiber diameter of about 1.5 obtained by a general melt blow method.
μ, a melt-blown non-woven fabric made of polypropylene with a basis weight of 15 g / m ² , and the distance between the applied electrode and the earth electrode was 7
cm, and passed through a corona discharge region with an applied voltage of 40 KV at a speed of 30 m / min to perform electret processing. The filter performance of the obtained electret sheet was 1.5 m / wind.
The average collection efficiency at a particle size of 0.3 μm was 92%.

Next, the electret-processed sheet is supplied to a melt-blown nonwoven fabric manufacturing apparatus, and melt-blown fibers are stacked and collected on the sheet. That is, a polypropylene resin having a melt index of 100 was blended with 5% by weight of a polypropylene resin having a melt index of 7 to obtain 3
A stick-out die that is melted at 10 ° C. and has a hole pitch of 1.0 mm, a hole diameter of 0.3 mm, and a number of holes of 1300 arranged in a row, and a tip of the die having a die structure of 0.4 mm coming out of an air slit hole. Extruded at a discharge rate of 1 kg / min.
Injection is performed together with hot air at 0 ° C. and a pressure of 0.3 kg / cm ² to melt-blown fibers having an average fiber diameter of 13 μm. At this time, the hot air coming out of both air slit holes caused a turbulent airflow due to those directly colliding with the side surface of the base and those directly acting on the polymer. In addition, 35 below the base
A rotary drum collecting device composed of a 50-mesh wire mesh surface provided with a suction device was installed at a position of cm, the electret processed sheet was supplied to the drum surface, and the basis weight of the injected melt blown fiber was 80 g / m2. The collection speed was adjusted to be as follows. The surface temperature of the electret-processed sheet was 70 ° C. by an infrared thermometer.

When the melt-blown fibers having an average fiber diameter of 13 μm are collected in a single layer, the number of shots is 1/100 cm 2.
An average fiber diameter of about 1.5μ which has one and is supplied to the laminate;
The melt-blown nonwoven fabric made of polypropylene with a weight per unit area of 15 g / m2 has a strong bond at the shot area, and the obtained composite meltblown nonwoven fabric electret-treated sheet and the peel strength of the meltblown fiber nonwoven fabric stretch at a constant rate with a 3 cm wide specimen. 9g / 3c as a result of measurement with a die tension tester
m, the rigidity by the 45-degree cantilever method according to JIS L 1096 was 23 cm. The filter performance of the composite meltblown nonwoven veneer obtained was 91% in average collection efficiency under the above measurement conditions, and there was no decrease in electret effect. When processed into a filter unit, the foldability was good, and no deformation or delamination due to wind speed during use was good.

As a comparative example 1, when the tip of the die of the die structure was a stick-out die protruding from an air slit hole of 0.1 mm, a shot was frequent and a hard sheet was obtained. It was not preferable as a filter unit material.

Comparative Examples 2 and 3 An average fiber diameter of about 1.5 obtained by a general melt blow method.
μ, a melt-blown non-woven fabric made of polypropylene with a basis weight of 20 g / m ² , and the distance between the applied electrode and the earth electrode was 7
cm, and passed through a corona discharge region with an applied voltage of 40 KV at a speed of 30 m / min to perform electret processing. The filter performance of the obtained electret sheet was 1.5 m / wind.
The average collection efficiency at a particle diameter of 0.3 μm was 97%, and the pressure loss was 1.3 mmAq. The meltblown nonwoven fabric is supplied to a meltblown nonwoven fabric manufacturing apparatus, and meltblown fibers made of polypropylene having an average fiber diameter of 3 μm and a basis weight of 80 g / m ² are sprayed on the sheet, and the meltblown fibers are 35 cm below a die (Comparative Example 2). ), 10 cm (Comparative Example 3)
Was collected at the position of.

As a result, in Comparative Example 2, the peel strength was 3 cm in width.
2 g
The rigidity according to the 45-degree cantilever method according to JIS L 1096 was 8 cm. The laminated sheet was weak in adhesion and weak in stiffness. Delamination occurred in the filter unit production processing process such as slitting and folding, and the product could not be evaluated.

On the other hand, in the case of Comparative Example 3, fusion occurred between the two layers, and the adhesive strength was sufficient.
It was significantly higher than mmAq, making it unsuitable for filter media. The surface temperature of the electret-processed base material was 132 ° C. as measured by an infrared thermometer, and the electret disappeared remarkably.

[0046]

According to the present invention, the following excellent effects can be obtained by the configuration described in detail above.

That is, the melt-blown nonwoven fabric is widely used as a filter material. However, the meltblown nonwoven fabric alone is used as a filter unit in order to improve the crimping process, formability after folding process, and dust holdability. And it is often used as a composite material.

According to the present invention, a composite melt-blow sheet that can be used as various high-performance filter materials having different softness and fineness composition can be produced simply and at low cost using only a melt-blowing apparatus and an electret processing machine.

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁷ Identification code FI C08J 7/00 C08J 7/00

Claims (11)

(57) [Claims] 1. A fiber layer A and a melt-blown fiber layer B having an average fiber diameter of 5 μ or more are bonded using a shot as an adhesive.
And a JISL 1 of the sheet.
The rigidity by the 45-degree cantilever method according to 096 is 1
A composite melt blown sheet having a size of 5 cm or more. 2. A composite meltblown sheet, the composite meltblown sheet according to claim 1, wherein in which at least one side is an electret. Wherein the basis weight of the meltblown fibers, the composite meltblown sheet according to claim 1-2, wherein at 40 g / m @ 2 or more. Wherein the fiber layer A is a composite meltblown sheet according to claim 1 to 3 wherein the polypropylene. 5. A fiber layer A, the composite meltblown sheet according to claim 1-4, wherein the meltblown fibers. 6. A fiber blown fiber is provided on the fiber layer A.
The fiber layer B is laminated, collected and integrated to form a composite melt
In the method for producing a sheet, the fiber layer A and the melt
The shot fiber is bonded to the blown fiber layer B as an adhesive.
And the conditions for forming the meltblown fiber layer B are
Airflow of hot air jet when extruding high molecular polymer
The tip of the base is set at 0.2 to 0.7 mm
Composite melt broth characterized by disturbing conditions
Manufacturing method of the sheet. 7. A top of the fiber layer A, laminated fiber layers B consisting of meltblown fibers, and collecting, in manufacturing the composite meltblown sheets integrated with, the fiber layer A and the Merutobu
The raw fiber layer B does not adhere to the shot as an adhesive.
A method of producing a composite melt-blown sheet , wherein a resin blended with a resin having poor compatibility with each other is melt-blown as a resin forming the fiber layer B. 8. manufacturing fabrics conditions of the fiber layer B is The method of producing a composite meltblown sheet according to claim 6 or 7, wherein a condition to elicit 3 to 30 shots per 100cm2 fiber sheet after solidification. 9. A method in which melt-blown fibers are formed on the fiber layer A.
The fiber layer B is laminated, collected and integrated to form a composite melt
A method of manufacturing a Shito, the fiber layer A and the Mel
The shot fiber is bonded to the blown fiber layer B as an adhesive.
The fiber layer A is electret-processed, and the surface temperature of the fiber layer A at the time of laminating the fiber layer B is maintained at a temperature of 50 ° C. or lower than the melting point of the fiber layer A. A method for producing a composite melt-blow sheet. 10. An electret process on at least one side of the composite melt blown sheet.
8. The method for producing a composite melt blown sheet according to 6 or 7 . Filter units of the filter part 11. The filter unit, characterized in that it is a composite meltblown sheet according to claim 1 to 5 Claims.