JP7715329B2 - Apparatus for producing PET meltblown fiber web and method for producing PET meltblown fiber web using the same - Google Patents

Description

The present invention relates to a PET meltblown fiber web manufacturing apparatus and a PET meltblown fiber web manufacturing method using the same.

This section provides background art related to the present invention, and does not necessarily mean that it is publicly known. The meltblown process generally involves producing a fiber web using polypropylene (PP) as a raw material, and PP meltblown fiber webs are widely used in various high-performance filters, oil-absorbent fabrics, thermal insulation materials, sound-absorbing materials, etc.

However, polypropylene (PP) has a characteristic melting point of approximately 160°C, making it difficult to apply in industrial fields that require high heat resistance of 150°C or higher. To solve this problem, polyethylene terephthalate (PET) meltblown fiber webs, which have a melting point of approximately 255°C and offer excellent heat resistance, physical properties, and recyclability, are widely used.

However, PET meltblown fiber webs have a slower crystallization rate than other crystalline polymer materials, and shrinkage occurs at around 70°C (near the glass transition temperature, Tg), making them difficult to immediately use in products without post-processing such as heat treatment. Shrinkage occurs because, due to the nature of polymer materials, there are crystalline and amorphous regions. In the glass transition temperature range, the amorphous regions become mushy, causing the existing shape to be lost and shrinking.

Conventional PET meltblown fiber webs are heat-treated by applying hot air at a temperature between 100°C and 200°C on a forming table where the fiber web is collected.

However, when conventional PET meltblown fiber webs are heat-treated, hot air is not uniformly transferred at a uniform temperature to the PET meltblown fiber web captured on the forming table, resulting in differences in crystallization speed. This not only results in differences in the dimensions and thickness of the resulting PET meltblown fiber web, but also in the formation of an uneven fiber web. Another problem is that the thickness of the resulting fiber web cannot be adjusted when conventional PET meltblown fiber webs are heat-treated.

Korean Patent No. 10-0393869 Korean Patent No. 10-0714340 Korean Patent Publication No. 10-1988-0005308 Korean Patent No. 10-0466556

An object of the present invention is to provide a PET meltblown fiber manufacturing apparatus that crystallizes a PET meltblown fiber web at a high speed, thereby improving dimensional stability and productivity, and a method for manufacturing a PET meltblown fiber web using the same. An object of the present invention is to provide a PET meltblown fiber manufacturing apparatus that makes it possible to adjust the thickness of the PET meltblown fiber web produced, and a method for manufacturing a PET meltblown fiber web using the same. Furthermore, the problems that the present invention aims to solve are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

This provides a general summary of the invention, which should not be construed as limiting the scope of the invention.

The PET meltblown fiber web manufacturing apparatus of the present invention includes an extruder that melts and extrudes PET resin, a die that receives the molten resin extruded by the extruder and emits PET meltblown fibers that are ultra-thinned in the direction of their own weight, a forming table that is installed below the die and collects and assembles the PET meltblown fibers to form a PET meltblown fiber web, a winder that winds up the PET meltblown fiber web, and a blending nozzle that blends PET short fibers with the PET meltblown fibers emitted toward the forming table. The web manufacturing device includes a heat treatment machine that pressurizes and heat-treats a PET meltblown fiber web formed on a forming table. The heat treatment machine includes a perforated pressure belt that presses the PET meltblown fiber web toward the forming table and transports the PET meltblown fiber web toward the winder together with the perforated circulation belt of the forming table; a hot air supply chamber that supplies high-temperature hot air to the PET meltblown fiber web so that the PET meltblown fiber web being pressurized and transported by the perforated pressure belt is crystallized; and a height adjustment means that adjusts the height of the perforated pressure belt that pressurizes the PET meltblown fiber web.

In one aspect of the PET meltblown fiber manufacturing apparatus of the present invention, the perforated pressure belt is provided as a mesh belt, and is rotatably mounted on a carrier roller rotatably mounted between a pair of belt frames and a drive roller of a belt drive motor. The perforated pressure belt, which passes along the lower end of the belt frame, is installed lower than the lower end of the belt frame and passes horizontally between carrier rollers mounted on both sides of the lower end of the belt frame, and can press the surface of the PET meltblown fiber web toward the perforated circulation belt while transporting the PET meltblown fiber web toward the winder together with the perforated circulation belt.

In one aspect of the PET meltblown fiber manufacturing apparatus of the present invention, the hot air supply chamber is installed between the belt frames so as not to interfere with the perforated pressure belt, and is filled with hot air blown from a hot air duct installed outside the heat treatment machine. The lower part of the hot air supply chamber may be formed with multiple hot air injection nozzles that inject hot air toward the PET meltblown fiber web.

In one aspect of the PET meltblown fiber manufacturing apparatus of the present invention, one or more height adjustment means are installed on a height adjustment frame that is fixedly installed at a distance above the perforated pressure belt, and the height adjustment means may include a height adjustment servomotor installed in a gearbox installed on the upper surface of the height adjustment frame, and a lifting bar that operates in conjunction with the height adjustment servomotor to raise and lower the perforated pressure belt.

In one aspect of the PET meltblown fiber manufacturing apparatus of the present invention, a pinion gear is installed on the output shaft that rotates when the height adjustment servo motor is operated, and the lifting bar is installed in a gear box so that it can be raised and lowered. The lower end of the lifting bar passes through the height adjustment frame and is connected to the outer surface of the belt frame. The lifting bar may be formed with a rack gear that extends along the length of the lifting bar and engages with the pinion gear.

The method for producing PET meltblown fibers according to the present invention is characterized by comprising: a PET meltblown fiber emitting step in which PET raw materials are melt-blown and radiated in a meltblown manner to form PET meltblown fibers; a PET meltblown fiber web forming step in which the PET meltblown fibers seated on a perforated circulation belt are collected and aggregated to form a PET meltblown fiber web; and a pressurized heat treatment step in which high-temperature hot air is applied to the PET meltblown fiber web while pressurizing it to crystallize the PET meltblown fiber web.

In the PET meltblown fiber emission step of the PET meltblown fiber manufacturing method according to another aspect of the present invention, the PET meltblown fiber can be emitted at a temperature of 270 to 330°C at a rate of 25 to 60 m ³ /min and can be emitted to have a diameter of 2 to 5 μm.

In the PET meltblown fiber emission step of the PET meltblown fiber manufacturing method according to another aspect of the present invention, PET short fibers having a diameter of 15 to 40 μm are mixed with the emitted PET meltblown fibers, and the PET short fibers may be mixed with the PET meltblown fibers in a ratio of 3:7.

In the PET meltblown fiber web forming step of the PET meltblown fiber manufacturing method according to another aspect of the present invention, the perforated circulating belt is moved at a speed of 1 to 10 m/min, and a PET meltblown fiber web having a weight of 100 to 700 g/ ^m2 may be formed on the perforated circulating belt.

In the pressurized heat treatment step of the PET meltblown fiber web in the method for producing PET meltblown fiber according to another aspect of the present invention, the perforated pressure belt rotates circulatingly at a speed of 1 to 10 m/min along the transport direction of the PET meltblown fiber web, and the hot air supply chamber can spray high-temperature hot air at 80 to 200°C through the hot air spray nozzle at a speed of 1 to 10 ^m3 /min.

In another aspect of the present invention, in the pressurized heat treatment step of the PET meltblown fiber web in the method for producing PET meltblown fibers, the perforated pressure belt is spaced 1 to 150 mm from the perforated circulation belt, allowing the PET meltblown fiber web to be transferred under pressure.

According to the present invention, the collected fiber web is heat-treated while being pressurized, allowing the fiber web to crystallize uniformly and at a high speed. This shortened heat treatment time improves the productivity of PET meltblown fiber webs. According to the present invention, the collected fiber web is heat-treated while being pressurized, allowing the production of PET meltblown fiber webs with uniform thickness. According to the present invention, the pressure height of the collected fiber web can be adjusted, allowing the production of PET meltblown fiber webs with a variety of thicknesses.

1 is a schematic view of a manufacturing apparatus for a PET meltblown fiber web according to the present invention. 2 is a diagram illustrating the heat treatment machine of FIG. 1; 1 is a flow chart that schematically illustrates a method for producing a PET meltblown fibrous web according to the present invention. 4 is a flow chart that schematically illustrates the radiation stage of the PET meltblown fiber of FIG. 3.

Below, an embodiment of a PET meltblown fiber web manufacturing apparatus and a PET meltblown fiber web manufacturing method using the same according to the present invention will be described in detail with reference to the drawings.

The essential technical concept of the present invention is not limited in its possible implementation by the embodiments described below, but rather encompasses a range of possibilities that could be easily proposed by a person of ordinary skill in the art by replacing or modifying the embodiments described below based on the essential technical concept of the present invention. Furthermore, the terms used below have been selected for the convenience of explanation, and therefore, when grasping the essential technical concept of the present invention, they should not be limited to their dictionary meanings, but should be interpreted appropriately in a way that corresponds to the technical concept of the present invention.

FIG. 1 is a schematic diagram illustrating a PET meltblown fiber web manufacturing apparatus according to the present invention. Referring to FIG. 1, the PET meltblown fiber web manufacturing apparatus 100 according to the present invention has a configuration similar to that of conventional meltblown fiber web manufacturing apparatus (equipment). In other words, the PET meltblown fiber web manufacturing apparatus 100 according to the present invention includes an extruder 10 that melts and extrudes PET (polyethylene terephthalate) resin, a die 20 that receives the molten resin extruded by the extruder 10 and emits ultra-thinned PET meltblown fibers F in the direction of its own weight, a forming table 30 installed below the die 20 and collecting and concentrating the PET meltblown fibers F to form a PET meltblown fiber web W, and a winder 40 that winds up the PET meltblown fiber web W.

The PET meltblown fiber web manufacturing apparatus 100 according to the present invention further includes, like conventional meltblown fiber web manufacturing apparatuses, a two-fluid nozzle 50 that sprays fine droplets onto the PET meltblown fibers F emitted toward the forming table 30, and a blending nozzle 60 that air-blends (mixes) PET short fibers S into the PET meltblown fibers F emitted toward the forming table 30.

Here, the configurations of the extruder 10, die 20, forming table 30, winder 40, two-fluid nozzle 50, and blending nozzle 60, as well as their operational relationships, are well-known technologies and will not be described in detail.

Meanwhile, unlike conventional meltblown fiber web manufacturing apparatuses, the PET meltblown fiber web manufacturing apparatus 100 according to the present invention further includes a heat treatment device 110 that pressurizes and heat-treats the PET meltblown fiber web W collected and gathered on the forming table 30.

Figure 2 is a schematic diagram of the heat treatment machine shown in Figure 1. Referring to Figure 2, the heat treatment machine 110 of the PET meltblown fiber web manufacturing apparatus 100 according to the present invention includes a perforated pressure belt 120, a hot air supply chamber 130, and a height adjustment means 140.

First, the perforated pressure belt 120 presses the PET meltblown fiber web W formed on the forming table 30 toward the forming table 30, and together with the perforated circulation belt 32 of the forming table 30, transfers the PET meltblown fiber web W toward the winder 40. The perforated pressure belt 120 is provided as a mesh belt, and is provided in a closed loop shape with one end and the other end connected in an endless manner.

In the present invention, the perforated pressure belt 120 is not particularly limited, but as an example, the perforated pressure belt 120 is provided as a regular mesh belt. The perforated pressure belt 120 is rotatably mounted on a carrier roller 124 rotatably mounted between a pair of belt frames 122 and a drive roller 128 of a belt drive motor 126.

At this time, the porous pressure belt 120 passing along the lower end of the belt frame 122 is installed lower than the lower end of the belt frame 122 so as to pass horizontally over carrier rollers 124 installed on both sides of the lower end of the belt frame 122. In this way, the face of the porous pressure belt 120 passing horizontally along the lower end of the belt frame 122 presses the surface of the PET meltblown fiber web W, which is being transferred to the winder 40 side by the operation of the porous circulation belt 32 of the forming table 30, toward the porous circulation belt 32 of the forming table 30, and transfers the PET meltblown fiber web W toward the winder 40 together with the porous circulation belt 32.

To this end, the perforated pressure belt 120 rotates in a circular motion along the transport direction of the PET meltblown fiber web W by operation of the belt drive motor 126, which rotates the perforated pressure belt 120 at the same speed as the transport speed of the perforated circulation belt 32 of the forming table 30, preferably at a speed of 1 to 10 m/min. The face of the perforated pressure belt 120, which passes horizontally along the lower end of the belt frame 122, has its pressure position for pressing the PET meltblown fiber web W adjusted by operation of the height adjustment means 140, thereby allowing the PET meltblown fiber web W to be manufactured in a variety of thicknesses.

The hot air supply chamber 130 supplies high-temperature hot air to the PET meltblown fiber web W, which is being pressurized and transported by the perforated pressure belt 120, so as to crystallize the PET meltblown fiber web W. The hot air supply chamber 130 is installed between a pair of belt frames 122 so as not to interfere with the rotating perforated pressure belt 120, and is connected to a hot air duct (not shown) installed outside the heat treatment machine 110. At this time, the interior of the hot air supply chamber 130 is filled with hot air blown from the hot air duct. A number of hot air injection nozzles 132 are formed in multiple rows and columns at the bottom of the hot air supply chamber 130, which inject the hot air from inside the hot air supply chamber 130 toward the PET meltblown fiber web W.

The hot air supply chamber 130 installed in this manner sprays hot air at 80 to 200°C onto the PET meltblown fiber web W at a speed of 1 to 10 ^m3 /min through a plurality of hot air spray nozzles 132. Since the PET meltblown fiber web W is pressurized by the perforated pressure belt 120, the hot air sprayed through the plurality of hot air spray nozzles 132 can be transferred to the front and back surfaces of the PET meltblown fiber web W at a uniform temperature, thereby allowing the PET meltblown fiber web W to be uniformly crystallized (heat-treated).

The height adjustment means 140 adjusts the height of the perforated pressure belt 120, which applies pressure to the PET meltblown fiber web W, allowing the PET meltblown fiber web W to be manufactured in various thicknesses. One or more height adjustment means 140 are installed on a height adjustment frame 142, which is fixedly installed at a distance above the perforated pressure belt 120. Figure 2 shows two height adjustment means 140 installed on the height adjustment frame 142. The height adjustment means 140 includes a height adjustment servomotor 146 and a lifting bar 150 that operates in conjunction with the height adjustment servomotor 146 to raise and lower the perforated pressure belt 120.

The height adjustment servo motor 146 is installed in a gear box 144 installed on the upper surface of the height adjustment frame 142 as shown. At this time, a pinion gear 148 that meshes with the lifting bar 150 via the gear box 144 is installed on the output shaft (not shown) that rotates when the height adjustment servo motor 146 is operated.

The lifting bar 150 is provided in the form of a vertically extending bar and is installed in the gear box 144 so that it can be raised and lowered. At this time, the lower end of the lifting bar 150 passes through the height adjustment frame 142, and the lower end of the lifting bar 150 that passes through the height adjustment frame 142 is connected to the outer surface of the belt frame 122 so as not to interfere with the perforated pressure belt 120. In addition, the lifting bar 150 is formed with a rack gear 152 that extends along the length of the lifting bar 150 and engages with the pinion gear 148.

In other words, when the height adjustment servo motor 146 rotates the output shaft to one side or the other, the pinion gear 148 also rotates to one side or the other along the output shaft. As the pinion gear 148 rotates to one side or the other, the lifting bar 150, which is formed with a rack gear 152 that meshes with the pinion gear 148, moves up and down. As a result, the belt frame 122 and the perforated pressure belt 120 move up and down along the lifting bar 150, adjusting their heights.

Preferably, the height adjustment means 140 allows the perforated pressure belt 120 to pressurize and transport the PET meltblown fiber web W by adjusting the gap between the perforated circulation belt 32 of the forming table 30 and the perforated pressure belt 120 to a distance of 1 to 150 mm.

Below, a method for manufacturing a PET meltblown fiber web using a PET meltblown fiber web manufacturing apparatus will be described. Among the accompanying drawings, Figures 3 and 4 are flowcharts that outline a method for manufacturing a PET meltblown fiber web according to the present invention. The method for manufacturing a PET meltblown fiber web according to the present invention includes a step of emitting PET meltblown fibers (S10), a step of forming a PET meltblown fiber web (S20), and a step of pressurizing and heat-treating the PET meltblown fiber web (S30).

PET Meltblown Fiber Radiation Step (S10)
The PET meltblown fiber emission step (S10) is a step of forming PET meltblown fiber F by melt-ejecting PET (polyethylene terephthalate) polymer resin in a meltblown manner (S10).

The PET meltblown fibers F formed in the PET meltblown fiber emission step (S10) are melted and emitted perpendicularly toward the perforated circulation belt 32 through a die 20 that faces the perforated circulation belt 32 of the forming table 30 in a perpendicular direction. Here, the forming table 30 collects and assembles the PET meltblown fibers F to produce a PET meltblown fiber web W in the subsequent PET meltblown fiber web formation step (S20).

Meanwhile, the PET meltblown fiber spinning step (S10) will be described. The PET meltblown fiber spinning step (S10) includes a PET raw material loading step (S10-1), a PET raw material extrusion step (S10-2), and a PET raw material spinning step (S10-3). The PET raw material loading step (S10-1) is a step (S10-1) in which the prepared PET raw material is loaded into a dry hopper (not shown) connected to the extruder 10. In the PET raw material loading step (S10-1), the PET raw material can be loaded into the dry hopper via a conventional spring conveyor.

The PET raw material loaded into the dry hopper is then transferred to the extruder 10 installed below the dry hopper. During this process, the PET raw material is dried with hot air to a moisture content of approximately 0.01 to 1.0%. The PET raw material extrusion step (S10-2) involves receiving the PET raw material from the dry hopper, melting the PET raw material while transferring it, and extruding the molten PET raw material (S10-2). During the PET raw material extrusion step (S10-2), the PET raw material can be extruded at a rate of 1,250 g/min while maintaining a temperature of 280 to 300°C.

If the PET raw material is extruded at a temperature below 280°C, not only will it have poor flowability, placing a strain on the material, but it may also experience problems such as an increase in molecular weight, which could result in changes to its physical properties. If the PET raw material is extruded at a temperature above 300°C, thermal decomposition can cause a decrease in molecular weight, which could result in a decrease in physical properties and yellowing.

The extrusion speed of the PET raw material can be set differently depending on the melting temperature. However, if the extrusion speed is too slow, the PET raw material will remain in the extruder for a long time, resulting in a decrease in molecular weight due to thermal decomposition. If the extrusion speed is too fast, the PET raw material may not be melted. Therefore, the extrusion speed of the PET raw material is preferably 1,250 g/min. The molten PET raw material extruded from the extruder can be supplied to the PET raw material ejection step (S10-3) via a conventional screen changer (not shown) and gear pump (not shown).

The PET raw material ejection step (S10-3) is a step in which the molten PET raw material supplied in the PET raw material extrusion step (S10-2) is ejected in the form of ultra-thin fibers, or PET meltblown fibers, using high-temperature, high-pressure gas. The molten PET raw material supplied in the PET raw material ejection step (S10-3) passes through the die 20 and flows in the direction of its own weight through the ejection nozzle installed below the die 20. The molten PET raw material flowing through the ejection nozzle is stretched in the direction of its own weight and its diameter is reduced by the high-temperature, high-pressure gas sprayed from the side of the ejection nozzle, allowing it to be ejected in the form of ultra-thin PET meltblown fibers F.

Here, the high-temperature, high-pressure gas may be at 310 to 330°C and may be sprayed at a rate of 25 to 60 m ³ /min. However, if the temperature of the high-temperature, high-pressure gas is less than 310°C, the sprayed PET meltblown fiber F will quickly cool and become a hard fiber instead of a soft fiber, and if the temperature of the high-temperature, high-pressure gas exceeds 330°C, thermal decomposition will occur and the fiber will turn yellow.

Preferably, in the PET meltblown fiber emission step (S10), the PET meltblown fiber F is emitted to have a diameter of 2 to 10 μm. However, if the diameter of the PET meltblown fiber F is less than 2 μm, it is difficult to work with and it is difficult to establish stable process conditions, and if the diameter of the PET meltblown fiber F exceeds 10 μm, the sound absorption performance decreases.

Meanwhile, in the PET meltblown fiber discharging step (S10), a PET staple fiber air blending step (not shown) for mixing in PET staple fibers S may be optionally added. The PET staple fiber air blending step is intended to impart bulkiness to the PET meltblown fiber web W being produced, and the PET staple fibers S can be air blended (mixed) with the PET meltblown fibers F being discharged toward the forming table 30 through the blending nozzle 60.

Here, the PET staple fibers S have a diameter of 15 to 40 μm. If the diameter of the PET staple fibers S is 15 μm, it is difficult to impart bulkiness to the PET meltblown fiber web W produced. If the diameter of the PET staple fibers S exceeds 40 μm, the bulkiness is improved, but the cotton density of the PET meltblown fiber web W produced is inferior, resulting in reduced sound absorption performance.

As an example, to improve sound absorption performance in the low frequency range (below 1,000 Hz), PET meltblown fiber F and PET staple fiber S are blended in a ratio of 3:7, and to improve sound absorption performance in the mid- to high frequency range (above 1,000 Hz), PET meltblown fiber F and PET staple fiber S are blended in a ratio of 7:3. In other words, the blending ratio of PET meltblown fiber F and PET staple fiber S may vary depending on the intended use of the PET meltblown fiber web produced, and PET meltblown fiber F and PET staple fiber S are typically blended in a ratio of 5:5.

Formation of PET Meltblown Fiber Web (S20)
The PET meltblown fiber web forming step (S20) is a step of collecting and consolidating the PET meltblown fibers F seated on the perforated circulation belt 32 of the forming table 30 to form a PET meltblown fiber web W (S20).

In the PET meltblown fiber web formation step (S20), the PET meltblown fibers F are collected on the circulating, perforated circulating belt 32 and transported along the perforated circulating belt 32. The PET meltblown fibers F transported along the perforated circulating belt 32 are bonded by a conventional suction means provided on the forming table 30 to form a PET meltblown fiber web W.

Here, the forming table 32 may be disposed 10 to 100 cm away from the emitting nozzle that melts and emits the PET meltblown fiber F, and the perforated circulating belt 32 may be moved at a speed of 1 to 10 m/min. As a result, a PET meltblown fiber web W having a weight of 100 to 700 g/ ^m2 may be formed on the perforated circulating belt 32. However, if the distance between the forming table 32 and the emitting nozzle and the moving speed of the perforated circulating belt 32 are less than or exceed the critical values, it is not possible to form a PET meltblown fiber web W having a weight of 100 to 700 g/ ^m2 .

For example, if the transfer speed of the perforated circulating belt 32 is set to 5 m/min in the PET meltblown fiber web formation step (S20), a PET meltblown fiber web W having a weight of 400 g/ ^m² can be formed. In addition, in the PET meltblown fiber web formation step (S20), the suction pressure of the suction means is not particularly limited in the present invention, but is set within a range in which the collected PET meltblown fiber web W does not become excessively dense and does not scatter. In this manner, the PET meltblown fiber web W formed in the PET meltblown fiber web formation step (S20) is transferred to the winder 40 side.

Pressurized Heat Treatment Step of PET Meltblown Fiber Web (S30)
The pressurized heat treatment step (S30) of the PET meltblown fiber web is a step (S30) of crystallizing the PET meltblown fiber web W by applying high-temperature hot air while pressurizing the PET meltblown fiber web W formed in the preceding PET meltblown fiber web formation step (S20) so as not to interfere with the transport of the PET meltblown fiber web W.

In the pressurized heat treatment step (S30) of the PET meltblown fiber web, the PET meltblown fiber web W formed on the forming table 30 is pressed toward the porous circulation belt 32 of the forming table 30 by the porous pressure belt 120 of the heat treatment machine 110, and the PET meltblown fiber web W pressed by the porous pressure belt 120 is crystallized by high-temperature hot air sprayed through the hot air spray nozzles 132 formed in the hot air supply chamber 130 of the heat treatment machine 110.

At this time, the porous pressure belt 120 rotates at a speed of 1 to 10 m/min, which is the same as the transport speed of the porous circulation belt 32, and circulates in the transport direction of the PET meltblown fiber web W. The hot air injection nozzles 132 may spray high-temperature air at 80 to 200°C at a speed of 1 to 10 ^m /min, and preferably, the hot air injection nozzles 132 may spray high-temperature air at 160°C at a speed of 6 ^m /min.

Here, if the high-temperature hot air is below 80°C, crystallization of the amorphous region will not occur even if stabilization heat treatment is carried out below the PET glass transition temperature and crystallization temperature, and shrinkage will occur at temperatures above 120°C. If the high-temperature hot air exceeds 200°C, severe shrinkage will occur, and the PET meltblown fiber web produced will become hard and yellow, which can be a problem.

Furthermore, if the injection rate of the high-temperature hot air is less than 1 m ³ /min, the diameter of the produced PET meltblown fiber web becomes too large and the PET meltblown fiber web does not form a fibrous shape, whereas if the injection rate of the high-temperature hot air is more than 10 m ³ /min, the diameter of the produced PET meltblown fiber web becomes too small and the PET meltblown fiber web not only becomes scattered but is not collected on the forming table 30. In the pressurized heat treatment step (S30) of the PET meltblown fiber web, the porous pressure belt 120 forms a gap of 1 to 150 mm with the porous circulation belt 32 of the forming table 30 by the height adjustment means 140 of the heat treatment machine 110 to pressurize and transfer the PET meltblown fiber web W. As a result, the PET meltblown fiber web W can be produced in various thicknesses corresponding to the gap between the porous pressure belt 120 and the porous circulation belt 32.

Meanwhile, after the PET meltblown fiber web has been subjected to the pressurized heat treatment step (S30), a nonwoven fabric (not shown) or the like can be heat-pressurized and bonded to the front and back surfaces of the PET meltblown fiber web W. According to the present invention, the PET meltblown fiber web W is heat-treated while being pressurized, allowing the PET meltblown fiber web W to be crystallized uniformly and quickly. This shortened heat treatment time can improve the productivity of the PET meltblown fiber web W.

According to the present invention, a PET meltblown fiber web W is heat-treated while being pressurized, making it possible to produce a PET meltblown fiber web W with a uniform thickness. According to the present invention, the pressure height of the PET meltblown fiber web W can be adjusted, making it possible to produce a PET meltblown fiber web W with a variety of thicknesses.

REFERENCE SIGNS LIST 10 extruder 20 die 30 forming table 32 perforated circulation belt 40 winder 50 two-fluid nozzle 60 blending nozzle 100 PET meltblown fiber web manufacturing apparatus 110 heat treatment machine 120 perforated pressure belt 122 belt frame 124 carrier roller 126 belt drive motor 128 drive roller 130 hot air supply chamber 132 hot air injection nozzle 140 height adjustment means 142 height adjustment frame 144 gear box 146 height adjustment servo motor 148 pinion gear 150 lifting bar 152 rack gear

Claims (8)

An apparatus for producing a PET meltblown fiber web, comprising: an extruder for melt-extruding a PET resin; a die for receiving the molten resin extruded by the extruder and emitting PET meltblown fibers that are extremely thinned in the direction of their own weight; a forming table installed below the die and spaced apart to collect and gather the PET meltblown fibers to form a PET meltblown fiber web; a winder for winding up the PET meltblown fiber web; and a blending nozzle for blending PET short fibers with the PET meltblown fibers emitted toward the forming table,
The PET meltblown fiber web manufacturing apparatus includes:
a heat treatment machine that applies pressure to the PET meltblown fiber web formed on the forming table and heat treats the web;
The heat treatment machine is
a perforated pressure belt provided as a mesh belt and rotatably installed on a carrier roller rotatably installed between a pair of belt frames and a drive roller of a belt drive motor, which presses the PET meltblown fiber web toward the forming table and transfers the PET meltblown fiber web toward the winder together with the perforated circulation belt of the forming table;
a hot air supply chamber for supplying high-temperature hot air to the PET meltblown fiber web so that the PET meltblown fiber web being pressurized and transferred by the perforated pressure belt is crystallized;
a height adjusting means for adjusting the height of the perforated pressure belt that presses the PET meltblown fiber web ;
The perforated pressure belt passing through the lower end side of the belt frame is installed lower than the lower end of the belt frame so as to horizontally pass through the carrier rollers installed on both sides of the lower end of the belt frame, and presses the surface of the PET meltblown fiber web against the perforated circulation belt, and transfers the PET meltblown fiber web to the winder side together with the perforated circulation belt,
The height adjusting means is installed on one or more height adjusting frames fixedly installed at a distance above the perforated pressure belt, and includes a height adjusting servomotor installed in a gear box installed on an upper surface of the height adjusting frame, and a lifting bar for lifting the perforated pressure belt in conjunction with the height adjusting servomotor, and a pinion gear is installed on an output shaft that rotates by operation of the height adjusting servomotor,
the lifting bar is installed in the gear box so as to be able to move up and down, and a lower end of the lifting bar passes through the height adjusting frame and is connected to an outer surface of the belt frame;
The apparatus for manufacturing a PET meltblown fiber web , wherein the lifting bar has a rack gear, which engages with the pinion gear, extending along the length of the lifting bar . The hot air supply chamber is installed between the belt frames so as not to interfere with the perforated pressure belt, and is filled with hot air blown from a hot air duct installed outside the heat treatment machine.
2. The apparatus for manufacturing a PET meltblown fiber web according to claim 1 , wherein a plurality of hot air injection nozzles for injecting hot air toward the PET meltblown fiber web are formed at a lower portion of the hot air supply chamber.
In the method for producing a PET meltblown fiber web using the PET meltblown fiber web production apparatus of claim 1,
A PET meltblown fiber radiation step (S10) of melting and radiating the PET raw material in a meltblown manner to form the PET meltblown fiber;
(S20) forming a PET meltblown fiber web by collecting and consolidating the PET meltblown fibers seated on the perforated circulation belt;
and (S30) applying pressure to the PET meltblown fiber web and providing high-temperature hot air to crystallize the PET meltblown fiber web. In the PET meltblown fiber emission step (S10),
The method for producing a PET meltblown fiber web according to claim 3, wherein the PET meltblown fibers are emitted at a temperature of 270 to 330°C at a rate of 25 to 60 m ³ /min and have a diameter of 2 to 10 μm. In the PET meltblown fiber emission step (S10),
The emitted PET meltblown fibers are mixed with PET short fibers having a diameter of 15 to 40 μm,
In order to improve sound absorption performance in the low frequency range, the PET short fibers and the PET meltblown fibers are blended in a weight ratio of 3:7.
4. The method for producing a PET meltblown fiber web according to claim 3, wherein the PET short fibers and the PET meltblown fibers are mixed in a weight ratio of 7:3 to improve sound absorption performance in the mid- to high-frequency ranges . In the step of forming the PET meltblown fiber web (S20),
The perforated circulating belt is moved at a speed of 1 to 10 m/min,
The method for producing a PET meltblown fiber web according to claim 3 , wherein the PET meltblown fiber web having a weight of 100 to 700 g/ ^m2 is formed on the perforated circulation belt. In the pressurized heat treatment step (S30) of the PET meltblown fiber web,
The perforated pressure belt rotates at a speed of 1 to 10 m/min along the transport direction of the PET meltblown fiber web,
4. The method for producing a PET meltblown fiber web according to claim 3 , wherein the hot air supply chamber sprays hot air at a temperature of 80 to 200° C. through a hot air spray nozzle at a speed of 1 to 10 m ³ /min. In the pressurized heat treatment step (S30) of the PET meltblown fiber web,
8. The method for producing a PET meltblown fiber web according to claim 7, wherein the perforated pressure belt is spaced from the perforated circulation belt by 1 to 150 mm, and pressurizes and transfers the PET meltblown fiber web.