One]This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0152012 dated November 25, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification.
[2]
The present invention relates to an extrusion apparatus for extruding a raw material in a solid state containing moisture, and more particularly, an extrusion in which a section in which the raw material forms a sealing film is provided in the barrel in order to prevent the water vapor discharged from the raw material from flowing backward. It's about the device.
[3]
background
[4]
In the manufacturing process of a thermoplastic resin produced by emulsion polymerization, the raw materials contain a large amount of moisture because the produced thermoplastic resin is generally obtained in a latex state together with a dispersion medium.
[5]
Accordingly, the manufacturing process of the thermoplastic resin includes dehydration and drying processes to remove moisture.
[6]
In the known drying process, a method of evaporating moisture by applying thermal energy while the dehydrated raw material is moving or in a stationary state is generally performed.
[7]
After that, if necessary, the dried raw material was heated and pressurized using an extrusion apparatus as shown in FIG. 1 to obtain the dried raw material as pellets.
[8]
Referring to FIG. 1 showing the inside of the conventional extrusion apparatus through a perspective view, the conventional extrusion apparatus is provided with a hopper 2 into which raw materials are put on one side of a tubular barrel 1, and an internal screw 5 is installed. It is configured to be discharged through the outlet (the left outlet in the drawing).
[9]
The raw material injected through the hopper 2 is heated through a heater (not shown) mounted inside or outside the barrel and pressed by the screw 5 . Accordingly, water vapor generated from the moisture remaining in the dried raw material while being moved by the screw 5 is separated. The separated water vapor is discharged to the outside through the vent part 6 disposed at a distance from the hopper 2 .
[10]
However, in this conventional structure, there is a problem that the water vapor generated in the barrel 1 while the raw material passes through the screw 5 does not reach the vent 6 and may flow back into the hopper 2 . Such counterflow of water vapor adversely affected smooth raw material input, and there was a problem of impairing extrusion performance.
[11]
In order to solve this problem, in the related art, a prevention plate 4 for minimizing the effect of water vapor backflow and an input screw 3 for forcibly injecting raw materials into the barrel are additionally mounted on the hopper 2 .
[12]
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[13]
Therefore, the main object of the present invention is to provide an extrusion apparatus capable of directly extruding the dehydrated raw material without the drying step, and preventing the water vapor separated from the raw material from flowing back into the hopper, thereby increasing the extrusion efficiency. .
[14]
means of solving the problem
[15]
The present invention for achieving the object as described above, in an extrusion apparatus for extruding a raw material in a solid state containing moisture, has a hollow tube shape along the longitudinal direction, and a hopper into which the raw material is input is coupled to one side and , a barrel formed with a discharge port through which the dehydrated raw material is discharged on the other side; a screw mounted inside the barrel and having a rod shape to transfer the raw material input from the hopper to the discharge port while rotating in one direction and having a screw thread formed on an outer circumferential surface; a vent part disposed at any one point between the hopper and the outlet and discharging the vapor generated in the barrel to the outside; and a heater unit mounted on the barrel to heat the raw material, wherein the raw material introduced into the barrel through the hopper is gradually heated by the heater unit while being transferred in the barrel through the screw, and the screw has a screw thread. A kneading zone is formed in which compression of the raw materials transferred by the It is characterized in that the heating temperature of the heater and the shaft rotation speed of the screw are controlled so that the raw material forms a sealing film that shields the inner cross section of the barrel in the kneading zone.
[16]
The kneading zone is disposed between the vent unit and the hopper.
[17]
The distance between the kneading zone and the vent part is formed to be shorter than a length that is three times the diameter of the barrel. And, the distance between the kneading zone and the hopper is formed to be longer than the length that is 5 times the diameter of the barrel.
[18]
The screw includes: a first forward zone in which a thread is formed so that the raw material input from the hopper is transferred toward the outlet when the screw is rotated; a kneading zone in which a screw thread is formed to compress the raw material transferred from the first forward zone when the shaft rotates; and a second forward zone in which a thread is formed so that the raw material passing through the kneading zone is transferred toward the outlet when the shaft rotates.
[19]
The kneading zone may include a; Alternatively, the kneading zone may include; a reverse zone in which a thread is formed on the outer peripheral surface of the rod-shaped to transport the raw material in the opposite direction to the thread formed in the first forward zone. Alternatively, the kneading zone includes a neutral zone in which a thread is formed on the rod-shaped outer peripheral surface to induce in-situ rotation of the raw material, and a reverse zone in which a thread is formed to transfer the raw material in the opposite direction to the thread formed in the first forward zone on the rod-shaped outer peripheral surface. It is configured to be connected, and the neutral zone may be connected to the first forward zone, and the reverse zone may be arranged to be connected to the second forward zone.
[20]
In addition, the screw may further include a sub-kneading zone in which a thread is formed so that recompression of the raw material transferred from the second forward zone is made when the screw rotates.
[21]
The distance between the sub-kneading zone and the vent part is formed to be longer than a length that is three times the diameter of the barrel.
[22]
And, the screw further includes a third forward zone in which a thread is formed so that the raw material that has passed through the sub-kneading zone is transferred toward the discharge port when the screw rotates, and within the range in which the third forward zone is formed, the barrel contains the raw material. A sub-vent part for discharging the contained impurities to the outside may be formed.
[23]
The distance between the sub-kneading zone and the sub-vent part is formed to be shorter than a length that is three times the diameter of the barrel.
[24]
In addition, a pulverizing device for pulverizing the dried raw material discharged from the outlet of the barrel may be further included.
[25]
Effects of the Invention
[26]
In the extrusion apparatus of the present invention having the above configuration, a sealing film is formed in the kneading zone while the extrusion of the raw material is in progress in the barrel, thereby preventing or minimizing the reverse flow of water vapor toward the hopper.
[27]
Since the kneading zone may include one of a neutral zone or a reverse zone, or a combination of both, it may be selectively applied according to the state and properties of the raw material.
[28]
In addition, in the present invention, since the screw may further include a sub-kneading zone, it is possible to form an additional sealing film, thereby more effectively blocking the reverse flow of water vapor.
[29]
Brief description of the drawing
[30]
1 is a perspective view showing the inside of a conventional extrusion device through a perspective view.
[31]
Figure 2 is a perspective view showing the inside of the extrusion apparatus according to the present invention through a perspective view.
[32]
FIG. 3 is an enlarged view of a section in which a kneading zone is formed in FIG. 2 .
[33]
Figure 4 is a view showing embodiments (A, B, C) of the threads that can be applied to the kneading zone of the present invention.
[34]
5 is a view showing cross-sectional views before and after the sealing film is formed in the kneading zone.
[35]
Figure 6 is a view showing each relative distance based on the diameter (D) of the barrel in the extrusion apparatus of the present invention.
[36]
Modes for carrying out the invention
[37]
Hereinafter, based on the accompanying drawings, the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.
[38]
In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.
[39]
In addition, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor appropriately defines the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention based on the principle that it can be done.
[40]
The present invention relates to an extrusion apparatus for extruding a raw material in a solid state containing moisture. Hereinafter, an extrusion apparatus according to the present invention will be described in more detail with reference to the accompanying drawings.
[41]
Referring to FIG. 2 , which is a perspective view of the inside of the extrusion apparatus according to the present invention, the extrusion apparatus according to the present invention includes a barrel 10, a screw 30 mounted in the barrel 10, and the inside of the barrel 10 It is characterized in that it includes a vent unit 40 for discharging the water vapor of the outside, and a heater unit 60 for heating the barrel 10 . And, inside the barrel 10, a sealing film is formed by the molten raw material.
[42]
The barrel 10 has a hollow pipe shape along the longitudinal direction, a hopper 20 into which the raw material is input is coupled to one side, and a discharge port 11 through which the dehydrated raw material is discharged is formed on the other side.
[43]
The barrel 10 is preferably made of a metal with excellent chemical resistance to prevent corrosion by volatile substances and water vapor discharged from the raw material, or the inner surface is coated with a protective material, etc. It is manufactured to have sufficient rigidity to withstand pressure.
[44]
The screw 20 has a rod shape, and has a structure in which threads (M: 31, 32, 33) are formed on an outer circumferential surface. Then, the raw material input from the hopper 20 is transferred to the discharge port 11 while being mounted inside the barrel 10 and rotating in one direction.
[45]
At this time, the screw 30 is spirally formed along the longitudinal direction on the outer circumferential surface of the screw 30, and the portion where the screw M is formed in the direction of moving the raw material toward the inlet is the forward zone (F1, F2, F3 section) The part where the thread is formed so that the movement of the raw material is stopped and only rotation is made, or the part where the thread is formed so that the reverse movement of the raw material (i.e., moving from the outlet of the barrel to the hopper) is made is divided into a kneading zone (30A). .
[46]
That is, referring to FIG. 3 showing the enlarged section K1 in which the kneading zone 30A is formed in FIG. 2 and FIG. 4 showing the shape of the threads applicable to the kneading zone 30A, the kneading zone 30A ), the thread is configured to compress rather than feed the raw material. (The upper figure of FIG. 3 shows a case in which the case is coupled to the outside of the screw thread, and the lower figure is a state in which the case has been removed, so if described based on the lower figure), the kneading zone 30A is the raw material on the outer circumferential surface of the rod-shaped It may include a neutral zone in which the neutral thread 32 is formed so as to induce the in-situ rotation of the , and/or a reverse zone in which the reverse thread 33 is formed to transfer the raw material to the rod-shaped outer circumferential surface in the reverse direction. That is, the present invention provides a configuration in which a kneading zone is provided only with a neutral zone, a configuration in which a kneading zone is provided only with a reverse zone, and a configuration in which the neutral zone and the reverse zone are combined as Examples 1, 2, and 3, respectively.
[47]
The neutral screw thread 32 formed in the neutral zone is not in the form of a spirally connected thread as shown in FIG. etc.) may be formed. When the raw material arrives at the neutral screw thread 32 of this type, the force acting on the raw material is greater in the portion generating rotation in place than in transport.
[48]
And, the reverse screw thread 33 formed in the reverse zone is formed in the opposite direction to the screw thread formed in the forward zone, as shown in FIGS. 3 and 4 (B). This type of reverse thread 33 generates a force to feed the raw material in the opposite direction when it arrives.
[49]
Alternatively, as shown in (A) of FIG. 4 , the neutral zone and the reverse zone may be combined.
[50]
When the raw material arrives in the kneading zone 30A in which the neutral zone and/or the reverse zone is formed, the raw material is agglomerated with the rear raw material continuously supplied through the forward zone and subjected to pressure.
[51]
Meanwhile, in the present invention, the screw 30 may have sections F1, F2, F3 in which a plurality of forward zones are formed and sections K1 and K2 in which a plurality of kneading zones are formed. That is, as shown in Figure 2, from the side close to the hopper 20, the first forward zone (F1 section), the kneading zone (K1 section), the second forward zone (F2 section), the sub-kneading zone (K2 section), It has a structure in which a third forward zone (section F3) is disposed.
[52]
In the first forward zone, a forward screw thread 31 is formed so that the raw material input from the hopper 20 is transferred to the discharge port 11 when the shaft rotates, and the kneading zone 30A is the screw 30 when the shaft rotates. A neutral screw thread 32 or a reverse screw thread 33 is formed to compress the raw material transferred from the first forward zone. In addition, the sub-kneading zone 30B is also formed with a neutral thread 32 or a reverse thread 33 like the kneading zone 30A, and the second forward zone and the third forward zone have a forward thread like the first forward zone. is formed
[53]
In addition, after the raw material passes from the hopper 20 to the kneading zone 30A, the vent part 40 is mounted on the barrel 10 so that steam (and separated gas, etc.) is discharged. The vent unit 40 may be formed in the form of a simple tube opened to the upper side of the barrel 10, but an openable valve, an exhaust device for discharging water vapor by steel, and a safety vent that is opened only when the pressure is higher than a certain level are combined. may be provided.
[54]
In addition, a heater unit 60 for generating heat is coupled to the outer surface (or inside) of the barrel 10 . The heater unit 60 may be a device that converts electrical energy into thermal energy or a device that heats the barrel by receiving a heat source from the outside.
[55]
A plurality of the heater units 60 are mounted over the entire barrel, and each heater unit 60 is configured to be individually temperature controlled. Accordingly, the barrel 10 is configured to enable temperature control for each section (forwarding zone, kneading zone).
[56]
In the extrusion apparatus of the present invention having the configuration as described above, when the raw material stored in the hopper 20 is supplied into the barrel 10, the raw material is transferred inside the barrel 10 through the screw 30, and the heater Heating (and cooling) to the target temperature is achieved by the unit 60 .
[57]
At this time, when the raw material reaches the kneading zone 30A through the first forward zone, the raw material is pressed by the rotational force of the rear raw material and the screw 30 continuously supplied in a heated state.
[58]
Accordingly, the heated and pressurized raw material is melted in the kneading zone 30A (or before reaching the kneading zone), and at least a part or most of the raw material is phase-changed to a liquid state.
[59]
That is, the force is applied so that the raw material heated and pressurized in the kneading zone 30A is radially spread by the centrifugal force generated in the kneading zone 30A while the phase change is made from the solid state to the highly viscous liquid state.
[60]
Accordingly, as shown in FIG. 5 , which shows cross-sectional views before and after the sealing film is formed in the kneading zone 30A, the front side of the kneading zone 30A (closer to the hopper) is a solid raw material and separated from the raw material. Water vapor, etc. is spread into the space between the screw 30 and the barrel 10, and as heat and pressure are continuously applied, the back side of the kneading zone 30A (closer to the discharge port) is in a solid state. Most of the fuel is in a liquid state. is melted with At this time, the molten raw material forms a sealing film that shields the cross section of the barrel 10 by centrifugal force.
[61]
At this time, the thickness of the sealing film or the position at which it is formed may vary depending on the rotation speed of the screw 30 , the heating temperature of the heater unit 60 , and the configuration of the threads formed in the kneading zone 30A, but the sealing film is the barrel 10 ) is formed in a fluid state, not in a fixed state.
[62]
That is, the sealing film is formed as a liquid film, and as the raw material is continuously supplied, the raw material that first formed the sealing film is discharged to the second forward zone through the kneading zone 30A, and the raw material supplied later is liquid In this state, it replenishes the raw material discharged first and maintains the sealing film.
[63]
The heating temperature of the heater unit 60 and the shaft rotation speed of the screw are controlled according to the state and amount of the input material so that the sealing film can be continuously maintained.
[64]
The liquid raw material and gaseous water vapor that have passed through the kneading zone are transferred to the second forwarding zone area, where the liquid raw material is continuously transferred along the screw 30 while gaseous vapor (and phase gas generated during change) is discharged to the outside through the vent unit 40 . At this time, the reverse flow of the water vapor to the hopper 20 is blocked by the sealing film formed in the kneading zone 30A.
[65]
Then, the raw material that has reached the sub-kneading zone 30B forms a sealing film again in the sub-kneading zone 30B, and is discharged to the outlet 11 through the third forward zone. While being transported through the third forward zone, impurities (residual monomers, etc.) contained in the raw material, gas generated during phase change, and excess water vapor are discharged to the outside through the sub-vent unit 50 .
[66]
At this time, the raw material discharged to the discharge port 11 of the barrel 10 is discharged in the form of a solid mass after the separation of water vapor and gas and cooling.
[67]
The raw material discharged in the form of a solid mass is cut into pellets of a certain size by the crushing device 70 for pulverizing the dehydrated (dried) raw material.
[68]
On the other hand, in the extrusion apparatus of the present invention, it is preferable that the distance between each component is limited to increase drying and dehydration performance.
[69]
That is, as shown in FIG. 6 showing the respective relative distances based on the diameter (D) of the barrel in the extrusion apparatus of the present invention, based on the diameter (D) of the barrel 10, the hopper 20 It is preferable that the distance from the kneading zone 30A is set to 5D to 10D, and the distance between the kneading zone 30A and the vent part 40 is within 3D, between the vent part 40 and the sub-kneading zone 30B. It is preferable that the distance of is more than 3D, and the distance between the sub-kneading zone 30B and the sub-vent unit 50 is set within 3D. However, these relative distances are not limited to the above range, and may vary depending on the length of the screw 30 , the shaft rotation speed, the state of the raw material, the output of the heater unit 60 , and the like.
[70]
In the extrusion apparatus of the present invention having the above configuration, a sealing film is formed in the kneading zone 30A while dehydration of the raw material is in progress in the barrel 10, thereby preventing or minimizing the reverse flow of water vapor toward the hopper 20. have an effect
[71]
The kneading zone 30A may include one of a neutral zone or a reverse zone, or a combination of both, and thus may be selectively applied according to the state and properties of the raw material.
[72]
In addition, in the present invention, since the screw 30 may further include a sub-kneading zone 30A, it is possible to form an additional sealing film to more effectively block the reverse flow of water vapor, and to discharge water vapor from the vent unit 40 as much as possible. it may be possible to
[73]
In addition, in the extrusion device of the present invention, since the moisture contained in the raw material is discharged to the vent unit 40 at the same time as the extrusion, it may be possible to discharge impurities (residual monomers, etc.) contained in the raw material in the sub vent unit 50 as much as possible. there is.
[74]
On the other hand, the extrusion apparatus of the present invention may be an apparatus for extruding a thermoplastic resin. The thermoplastic resin may be a thermoplastic resin that can be pelletized through an extrusion device, and as a specific example, may be a diene-based graft copolymer. As a more specific example, the diene-based graft copolymer may be an acrylonitrile-butadiene-styrene-based graft copolymer.
[75]
The diene-based graft copolymer is generally prepared by an emulsion polymerization method, and is obtained in a latex state, that is, in a solid state containing moisture, in which the fine particles of the diene-based graft copolymer are dispersed in a colloidal state in a dispersion medium. do. Thereafter, the diene-based graft copolymer obtained in the latex state is obtained as a dry powder through aggregation, dehydration and drying steps. However, the diene-based graft copolymer obtained in the dry powder form has a problem in that caking occurs due to agglomeration and coagulation of the dry powder during long-term storage.
[76]
However, since the extrusion device of the present invention can effectively remove moisture from the solid raw material containing moisture at the same time as extrusion, when extruding the diene-based graft copolymer using the extrusion device of the present invention, latex There is no need for a drying process for the diene-based graft copolymer obtained in the state, and it may be possible to directly extrude the dehydrated diene-based graft copolymer.
[77]
In addition, the diene-based graft copolymer extruded using the extrusion device of the present invention has a higher bulk density compared to the dry powder, thereby preventing the caking phenomenon during long-term storage.
[78]
As such, the extrusion apparatus of the present invention may be more effective in obtaining a thermoplastic resin, a specific example of a diene-based graft copolymer, and a more specific example of an acrylonitrile-butadiene-styrene-based graft copolymer.
[79]
Although the present invention has been described with reference to limited examples and drawings, the present invention is not limited thereto, and it is described below with the technical idea of ​​the present invention by those of ordinary skill in the art to which the present invention pertains. Various implementations are possible within the scope of equivalents of the claims to be made.
[80]
[Explanation of code]
[81]
10 : Barrel
[82]
20 : Hopper
[83]
30: screw
[84]
40: vent part
[85]
50: sub vent unit
[86]
60: heater unit

WE CLAIMS

In the extrusion apparatus for extruding a raw material in a solid state containing moisture, a barrel having a hollow tubular shape along the longitudinal direction, a hopper into which the raw material is input is coupled to one side, and a discharge port through which the dehydrated raw material is discharged is formed on the other side ; a screw mounted inside the barrel and having a rod shape to transfer the raw material input from the hopper to the discharge port while rotating in one direction and having a screw thread formed on an outer circumferential surface; a vent part disposed at any one point between the hopper and the outlet and discharging the vapor generated in the barrel to the outside; and a heater unit mounted on the barrel to heat the raw material, wherein the raw material introduced into the barrel through the hopper is gradually heated by the heater unit while being transferred in the barrel through the screw, and the screw has a screw thread. A kneading zone is formed in which compression of the raw materials transferred by the Extrusion apparatus, characterized in that the heating temperature of the heater and the shaft rotation speed of the screw are controlled to form a sealing film that shields the
[Claim 2]
The extrusion apparatus according to claim 1, wherein the kneading zone is disposed between the vent part and the hopper.
[Claim 3]
The extrusion apparatus according to claim 2, wherein the distance between the kneading zone and the vent part is shorter than a length that is three times the diameter of the barrel.
[Claim 4]
The extrusion apparatus according to claim 2, wherein the distance between the kneading zone and the hopper is formed to be longer than a length that is 5 times the diameter of the barrel.
[Claim 5]
The method according to claim 2, wherein the screw comprises: a first forward zone in which a thread is formed so that the raw material input from the hopper is transferred toward the discharge port when the screw rotates; a kneading zone in which a screw thread is formed to compress the raw material transferred from the first forward zone when the shaft rotates; Extrusion apparatus comprising a; a second forward zone in which the screw thread is formed so that the raw material passing through the kneading zone is transferred toward the outlet when the shaft rotates.
[Claim 6]
[Claim 6] The extrusion apparatus according to claim 5, wherein the kneading zone includes a neutral zone in which a thread is formed on the rod-shaped outer peripheral surface to induce in-situ rotation of the raw material.
[Claim 7]
[Claim 6] The extrusion apparatus according to claim 5, wherein the kneading zone includes a reverse zone in which a thread is formed on an outer circumferential surface of a rod shape to transfer the raw material in a direction opposite to the thread formed in the first forward zone.
[Claim 8]
According to claim 5, wherein the kneading zone, a neutral zone, in which a thread is formed to induce the in-situ rotation of the raw material on the rod-shaped outer peripheral surface, and the thread formed in the first forward zone on the rod-shaped outer peripheral surface is threaded to transfer the raw material in the opposite direction The formed reverse zone is connected and configured, wherein the neutral zone is connected to the first forward zone, and the reverse zone is arranged to be connected to the second forward zone.
[Claim 9]
[Claim 6] The extrusion apparatus according to claim 5, wherein the screw further comprises a sub-kneading zone in which a thread is formed to recompress the raw material transferred from the second forward zone when the screw rotates.
[Claim 10]
[10] The extrusion apparatus according to claim 9, wherein the distance between the sub-kneading zone and the vent part is longer than three times the diameter of the barrel.
[Claim 11]
The method according to claim 9, wherein the screw further comprises a third forward zone in which a thread is formed so that the raw material passing through the sub-kneading zone is transferred toward the discharge port when the screw is rotated, and the third forward zone is formed within the range. Extrusion apparatus, characterized in that the barrel is formed with a sub-vent for discharging impurities contained in the raw material to the outside.
[Claim 12]
The extrusion apparatus according to claim 11, wherein the distance between the sub-kneading zone and the sub-vent part is shorter than a length that is three times the diameter of the barrel.
[Claim 13]
13. The extrusion apparatus according to any one of claims 1 to 12, further comprising a pulverizing device for pulverizing the raw material discharged from the outlet of the barrel.