KR920002396B1 - Extruder having degree of kneading adjusting device - Google Patents

Abstract

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Description

Extruder with kneading control

1 is a cross-sectional view of a multi-axial (two screw) extruder, that is, a first embodiment of the present invention, to which the technical concept of the present invention is applied.

FIG. 2 is a cross-sectional view showing a degree-of-kneading adjustment unit of a multi-screw extruder rotating in the same direction in FIG.

3 is a cross-sectional view taken along the line III-III of FIG.

4 is a cross-sectional view taken along the line IV-IV of FIG.

5 is a perspective view showing a kneading degree adjusting unit in the extruder of FIG.

6 is a sectional view of a second embodiment of the present invention.

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6. FIG.

8 is a sectional view taken along the line VII-VII of FIG.

9 is a perspective view of the kneading degree adjusting unit in the second embodiment of the present invention.

FIG. 10 is a cross-sectional view of the single screw extruder of the third embodiment of the present invention taken along the line VII-VII of FIG. 11. FIG.

FIG. 11 is a diagram showing the third embodiment when seen in the axial direction of the screw.

12 is a cross-sectional view taken along the line XII-XII of FIG.

FIG. 13 is a cross-sectional view showing a kneading degree adjusting unit of the multi-screw extruder rotating in the opposite direction in FIG.

FIG. 14 is a cross sectional view taken along the line XIV of FIG. 13;

15 is a sectional view of a second embodiment of the present invention for a multi-screw extruder rotating in the opposite direction.

FIG. 16 is a cross sectional view taken along the line XVI of FIG. 15;

Figure 17 is a flow diagram of the raw material in the cross section of the multi-screw extruder rotating in the same direction.

18 is a flow diagram of the raw material in the cross section of the multi-screw extruder rotating in the opposite direction.

The present invention relates to an extruder with a degree-of-kneading control.

Generally two types of extruders are known and used in practice, one is a single screw extruder (single screw extruder) and the other is a multi screw extruder (two screw extruder).

As disclosed in Japanese Unexamined Patent Application Publication No. 5,450,1975, in one example of a conventional kneading degree adjusting device, a cut is formed on a portion of a screw thread of a screw. The insertion member projecting into the inner surface of the extruder body receiving the screw is located in the cut so formed in the gap between the end of the insertion member and the screw being adjusted thereby.

In addition, an example of a conventional kneading degree adjusting device for a multi-screw extruder disclosed in Japanese Unexamined Patent Application No. 233408, 1986, is a gap between the groove of the screw and the groove of the cylinder is used to control the flow of raw materials during operation. This adjusts the kneading degree.

In the case of the prior art device of application 1233408, it is necessary to move the extruder barrel (or screw) as a whole for the purpose of adjusting the gap between the grooves. Thus, for example, it is necessary to position the entire body on the rail, which results in an inevitable complexity of the extruder and a fourth increase in the extruder components. The gap between the grooves also changes due to the difference in the amount of expansion between the body and the screw due to the temperature change. Therefore, it is difficult to effectively control the kneading degree with the conventional apparatus.

On the other hand, the conventional apparatus disclosed in the application No. 5450 in 1975 is still disadvantageous in that the above-mentioned difficulty is not provided but the kneading degree adjusting function is not sufficient. In particular, even if the gap between the insertion member and the screw is properly adjusted, it is difficult to control the overall flow of the resin as intended because some resin flows along the gap and other passages. That is, it is difficult to adjust the kneading degree to the expected value according to the temperature and physical properties of the resin.

It is therefore an object of the present invention to obviate the aforementioned problems associated with conventional kneading degree adjusters of extruders.

The above-mentioned problems are provided in accordance with the present invention by providing a single screw extruder having a kneading degree adjusting device in which a barrier wall is provided in the body hole of the extruder and the opening degree of the passage through which the upstream side and the downstream side of the barrier wall passes is controlled by a valve. Resolved. In particular, in the extruder having a kneading degree adjusting apparatus according to the present invention, the middle part of the screw is formed as a cylindrical portion having a diameter smaller than the screw thread, and the blocking wall is smaller than the diameter of the hole of the other barrel. It is interlocked with the circumference of the screw with a small gap in the axial direction at the position corresponding to the circumference of the screw in the hole of the body. Guided from the upstream side to the downstream side of the wall, a valve is provided in the delivery passage to adjust the opening degree of the delivery passage. The barrier wall may be in the form of a spiral continuous thread having two ends that overlap when viewed in the axial direction. In this case the valve is provided between two ends of the spiral continuous thread.

The molten raw material upstream of the barrier wall can only flow downstream through the delivery passage with the valve. As such, the area of the delivery passage in the device of the present invention may be adjusted for all openings in the range from fully closed to fully open of the passage. That is, the kneading degree can be adjusted to the expected value by adjusting the valve opening degree. Once the delivery passage is narrowed by adjusting the control valve, the feed balance is restricted from flowing through the delivery passage. As a result, the residence time and filling ratio of the feed resin in the kneading portion of the screw increases and the kneading degree increases.

According to the present invention, the above-mentioned problems are also solved by providing a kneading degree adjusting device in a multi-screw extruder in which the blocking walls are formed in two screw holes in the body and the transmission passage formed in the blocking wall is adjusted in the cross-sectional area. In particular, the object of the present invention described above is that the raw material fed into the two screw holes in the body into which the screw is inserted is heated and kneaded while being transported by two screws that interlock with each other to extrude the resin and rotate in the same or opposite directions. This is achieved by having a kneading degree adjuster for a multi-screw extruder. When viewed from the cross section of the body, the raw material fed into the screw channel moves around the inner surface as it travels downstream. Typical flow patterns of raw materials are 8-shaped for multi-screw extruders rotating in the opposite direction and bottle-shaped for multi-screw extruders rotating in the same direction. In order to control the different flow patterns of the raw material in the body, the delivery passage formed in the barrier wall is different from the multi-screw extruder rotating in the same direction and the effective mixing kneading is obtained.

According to the present invention, in a multi-screw extruder rotating in the same direction, each screw has a columnar portion adjacent to the downstream side of the kneading portion, and the diameter of the columnar portion is smaller than the diameter of the screw thread, and the blocking walls are smaller than that of other bodies, so The walls interlock with the circumferential portion of the screw with a small axial gap therebetween at a position corresponding to the circumferential portion in the two screw holes, separating the two screw holes into an upstream half and a downstream half. The barrier wall is in the form of a spiral continuous thread and its twist direction is determined such that the raw material is conveyed forward as the screw is rotated; One of the transmission passages causes the cranial side on the side of one of the two screw holes to communicate with the downstream side of the barrier wall on the side of the other screw hole, while the other transmission passage is the other of the two screw holes. The transmission passages through which the blocking cranial side on the side of the tube communicates with the downstream side on the side of one of the two screw holes are formed in a portion of the blocking walls and the portion is located between the two screw holes and the two Separating the screw holes of; Valve means for adjusting the cross sectional area of the transmission passage is provided in each of the transmission passages.

The barrier wall may be a simple vertical wall instead of a helical continuous thread. In this case, in the kneading degree adjusting apparatus according to the present invention, since each screw has a columnar portion on a part of the thread downstream of the kneading portion, the columnar portion is smaller in diameter than the thread, and the barrier wall is smaller in diameter than the other walls. The blocking wall is interlocked with the circumferential part of the screw with a small gap provided in the axial position corresponding to the circumferential part in the two screw holes, and the two blocking holes are separated upstream and downstream. It extends over the entire length of the circumferential portion of the screw, one of which passes into the downstream side of the blocking wall on both sides, while the other transfer passage is the side of the other of the two screw holes. The transmission passages are in such a way that the upstream side of the barrier wall on the upper side is in communication with the downstream side of the barrier wall on the side of one of the two screw holes. Formed in the barrier walls; Valve means for adjusting the cross sectional area of the transmission passage is provided in each transmission passage.

In the anti-rotating multi-screw extruder according to the present invention, the transfer passage is formed in a part of the barrier wall and the portion is introduced into the transfer passage and blocking the raw material moved to the barrier wall separating the two screw holes along the inner wall of the body. It is located on top of each screw to flow out downstream of the wall. The transmission passage formed in the blocking wall on the upper side and the lower side of each screw causes the upstream side of the blocking wall to communicate with the downstream side of the blocking wall in the body.

Molten raw material advancing upstream of the barrier wall can only flow downstream through the delivery passage with the valve. The area of the transmission passage can be changed by the control valve. When the delivery passage is narrowed by the control valve, the flow of resin through the delivery passage is limited, so that the residence time and filling ratio of the raw materials in the kneading section increase, and thus the kneading degree increases.

1 shows a multiaxial (two screw) extruder made by the first embodiment of the present invention.

This multi-screw extruder comprises a body 10 formed by connecting two screws 12, 13 (screw 13 is not shown in FIG. 1) fitted into two body of screws in several body units. In addition, the multi-screw extruder, the first transport unit 14, the kneading unit 16, the kneading degree adjustment unit 18, the second transport unit 20, the resin sealing portion 22, the degassing portion 24, the third And a conveying section 26 and an improving section 28, which are arranged in a predetermined order in the flow direction of the raw material to be handled.

As shown in Figs. 2 and 3, the kneading degree adjusting unit 18 has blocking walls 32 and 34 arranged in two screw holes formed in the body 30 formed of the upper half and the lower half. The inner diameters of the barrier walls 32 and 34 are slightly larger than the diameters of the columnar portions 12a and 13a of the screws 12 and 13 (without screw thread and the same diameter as the bone mill of the screw), respectively. The barrier walls 32 and 34 are in the form of spiral continuous threads. When the screws 12 and 13 rotate counterclockwise as in FIG. 2, the twisting direction of the spiral continuous thread causes the raw material to move smoothly (effectively) downstream of the barrier wall. The blocking walls 32 and 34 span about 360 degrees. The transmission passages 38 and 40 are formed in the partitions 36 and 37 which divide the two screw holes into the blocking walls 32 and 34, respectively. As shown in FIG. 5, the transmission passage 38 is formed by the upstream side of the blocking wall 32 in the hole on the side of the screw 12 of the blocking wall 34 in the hole on the side of the screw 13. While the delivery passage 40 is manufactured to communicate with the downstream side, the upstream side of the blocking wall 34 in the hole on the side of the screw 13 is the upstream side of the blocking wall 32 in the hole on the side of the screw 12. It is designed to communicate with the downstream side. That is, the transmission passages 38 and 40 are holes formed in the body at the top and bottom of FIG.

Valves 42 and 44 (a type of butterfly valve) are rotatably disposed on pivots 46 and 48. 2 shows valves 42 and 44 which allow two screw holes to pass through each other. From the state described in FIG. 2, when the valves 42 and 44 are rotated 90 degrees, the two screw holes are not connected to each other. The valves 42 and 44 rotate in opposite directions through the mechanism as shown in FIG. This will be described in more detail. As shown in FIG. 4, the fan-shaped gear 52 is arranged to rotate the shaft 50 which rotates together with the lower valve 44. As shown in FIG. Gear 52 engages gear 54, which is connected to bevel gear 58 via shaft 56. Bevel gear 58 meshes with gear 62 which is rotated by handle 60. Similarly, the upper valve 42 is connected to the bevel gear 62 through the fan-shaped gear 64, the gear 65 and the bevel gear 66. Thus, when the handle 60 is rotated, the valves 42 and 44 rotate in opposite directions. The operation of the multi-screw extruder rotating in the same direction thus produced will be described. The raw material in the body 10 of the extruder is moved by the screws 12, 13 from the upstream side to the downstream side or to the right side of FIG. Since the screws 12 and 13 rotate in the same direction, as shown in FIG. 17, the flow form of the raw material is in the form of a vial flowing in only one direction along the inner wall of the two screw holes as seen in the cross section of the screw, and the resin crosses. Do not flow. Since the kneading degree adjustment unit 18 restricts the flow of the raw material, the raw material is properly kneaded in the kneading unit 16. That is, the valves 42 and 44 can be operated by operating the handle 60 to adjust the cross-sectional area of the transmission passages 38 and 40 between the two screw holes, thereby adjusting the flow area of the raw material.

The delivery passages 38 and 40 are designed to guide the flow of the above-mentioned raw material along the inner wall. In FIG. 3, the position of the valve when the transverse cross section of the delivery passage is the widest is shown. Under this condition, when the valves 42 and 44 are rotated, the cross sectional area can be reduced. The delivery passages 38 and 40 are almost completely closed when the valve in the position shown in FIG. 3 is rotated 90 degrees. When the cross sectional area of the delivery passages 38 and 40 is reduced in the above-described manner, the resin accumulates in the kneading portion 16 and it is kneaded in the kneading cranial while largely sheared. The degree of kneading of the resin depends on the time of stay in the kneading section 16. Virtually all resin must pass through delivery passages 38 and 40. Therefore, the kneading degree can be adjusted to the expectation by controlling the opening degree of the transmission passage. The barrier wall is in the form of a spiral continuous thread, as described above, and the resin flows smoothly. As a result, the resin does not accumulate locally.

In the above-described embodiment, the valves 42 and 44 rotate to adjust the cross sectional area of the delivery passage but may be modified to move vertically with the modified valve as in FIG. 4, and the transfer passage between the two screw holes The cross sectional area of can also be effectively adjusted.

6 to 9, a second embodiment of the present invention will be described. The second embodiment includes barrier walls 33 and 35 extending vertically. The blocking walls 33 and 35 are provided over all the lengths of the columnar portions 12a and 13a of the screws 12 and 13. In other words, the threaded columnar portions 12a, 13a over the entire length have their respective blocking walls 33,35, with a small gap between the threaded ends 12b, 13b on the side of the columnar portion. It is fitted to the blocking walls 33 and 35 to face each other.

The transmission passages 39 and 41 are formed in the blocking walls 33 and 35. As shown in FIG. 9, the delivery passage 39 is formed by the upstream side of the blocking wall 33 in the hole on the side of the screw 12 of the blocking wall 35 in the hole on the side of the screw 13. It is formed so as to communicate with the downstream side, while the transmission passage 41 is formed by the upstream side of the blocking wall 35 in the yoke on the side of the screw 13 of the blocking wall 33 in the hole on the side of the screw 12. It is formed to communicate with the downstream side. As shown in Fig. 8, the valves 43 and 45 are provided in the transmission passages 39 and 41, respectively. (The valve 45 is not shown and is similar in structure to the valve 43). When the valves 43 and 45 are positioned as in FIG. 8, the two screw holes communicate with each other. In this state, when the valve rotates 90 °, the two screw holes do not communicate with each other. The valves 43 and 45 are rotated in opposite directions by a mechanism similar to that shown in FIG. 4 for the first embodiment.

In the second embodiment all resin also passes through the delivery passages 39 and 41. Therefore, similarly to the first embodiment, the kneading degree can be accurately adjusted by adjusting the opening degree of the valves 43 and 45. Also, in the second embodiment, although the fluidity of the resin is relatively low, it will not stagnate around the blocking walls 33 and 35. This is because the screw rotates with the threaded sections 12b, 13b adjacent to the barrier walls 33, 35, and therefore the resin near the barrier walls 33, 35 is stirred and transferred. During this operation, the resin is also sheared in small gaps between the threaded end faces 12b and 13b and the blocking walls 33 and 35.

In the third embodiment shown in Figs. 10 to 12, the concept of the present invention is applied to a single screw extruder. In the third embodiment, the blocking wall 33 is a threaded spiral. The helical twisting direction in which the thread is continuous determines the flow of raw material from the upstream side to the downstream end (ie, downward in FIG. 12) when the screw 12 rotates. Continuous threads spiral about 360 ° around the circumference of the screw and the circumferential ends form both sidewalls of the delivery passageway. The hole-shaped transfer passage 39 is provided between the threaded helical circumferential end portions and is provided with a vertically movable valve 43 in the transfer passage 39.

Also in this embodiment, as the screw 12 rotates, the resin flows from the upstream end to the downstream end of the thread. Virtually all the resin passes through the delivery passage 39 during this operation. Since the cross-sectional area of the transmission passage 39 can be adjusted by the valve 43, the kneading degree can be accurately adjusted to the expected value. As described above, the blocking wall 33 is a threaded spiral spiral and the resin flows smoothly along the blocking wall; That is, the resin never accumulates locally.

13 to 16 are other embodiments in which the inventive concept is applied to a multi-screw extruder rotating in opposite directions. Since the screws 12 and 13 rotate in opposite directions, the flow of the raw material is eight-shaped along the inner walls of the two screw holes when viewed in a cross-section outside the body as shown in FIG. Therefore, the barrier wall and the transmission passage are different from the embodiment of the multi-screw extruder rotating in the same direction. That is, the resin flows crosswise in the extruder rotating in the opposite direction. Therefore, the valve is arranged to optimally use these characteristics. In FIG. 13 four valves 102, 104, 106 and 108 are provided to reduce the resistance at the barrier wall. In the multi-screw extruder rotating in the opposite direction shown in FIGS. 13 and 14, the transmission passages 112, 114, 116, and 118 connecting the upstream and downstream sides of the barrier wall in the body have a barrier wall (up and down) of each screw. 122, 124, 126, and 128).

The multiaxial extruder rotating in the opposite direction shown in FIGS. 15 and 16 is provided with a valve 102 and two delivery passages 112 and 116. The transfer passages 112 and 116 are the portions placed on the upper portion of each screw, that is, the barrier walls, in such a manner that the raw material moved to the barrier wall separating the two screw holes along the inner wall of the body flows into the transfer passage and flows downstream of the barrier wall. Formed in portions of 122, 126.

As described above, according to the present invention, since the transmission passage is formed between the two screw holes and the passage is adjusted by the valve, the degree of kneading can be adjusted to the expected value.

Claims (6)

It has a pair of screws 12 and 13 fitted to the extruder body 30 and is heated and kneaded while the raw material fed through the two screw holes in the body is transported by the two screws 12 and 13 and the screws are In a multi-axial (two screw) extruder having a kneading degree adjusting device which rotates in the same direction while interlocking with each other for extruding the resin, the screw (12, 13) is a kneading portion (16). Adjacent to the downstream side of the columnar portion 12a, 13a and the diameter of the columnar portion is smaller than the thread diameter of the screw 12,13; The blocking walls 32 and 34 correspond to the circumferential portions in the two screw holes, and interlock with the circumferential portions of the screw with a small distance provided therebetween, and the two screw holes to the upstream side. Arranged downstream to separate; The barrier wall is a spiral with a threaded thread and its torsion direction is determined so that the raw material is transferred to the transfer passages 38 and 40 as the screw rotates, and the transfer passage is formed between the upper side between the two holes to separate the two screw holes. Located on the lower side and formed in the blocking wall; One of the transfer passages 38 is such that the upstream side of the blocking wall 32 on the side of one of the two screw holes is in communication with the downstream side of the blocking wall 34 on the side of the other of the two screw holes. And the other transmission passage 40 is such that the upstream side of the blocking wall 34 on the other side of the two screw holes is in communication with the downstream side of the blocking wall 32 on the side of one of the two screw holes. To; And a valve means (42,44) for adjusting the cross sectional area of said delivery passages (38, 40) is provided in each of said delivery passages. It has a pair of screws (12, 13) mounted in the body of the extruder, the raw material fed through the two screw holes in the body is heated and kneaded while being transported by the two screws, the screws interlock with each other to extrude the resin In a multi-axis (two screw) unidirectional rotary extruder rotating in the same direction with a kneading degree adjuster, which rotates in the same direction, each of the screws has a cylindrical portion 12a, 13a adjacent to the downstream side of the kneading portion. The diameter of the columnar portion is smaller than the thread diameter of the screw; The blocking walls 33 and 35 correspond to the circumferential portion in the two screw holes, and interlock with the circumferential portion of the screw with a small gap provided therebetween, and the two screw holes upstream. Arranged to separate downstream and downstream; The barrier wall extends over the entire length of the circumferential portion of the screw: one of the passages 39 is upstream of the barrier wall 33 on the side of one of the two screw holes, the other of the two screw holes. The other transmission passage 14 communicates with the downstream side of the blocking wall 35 on one side, and the other transmission passage 14 is the upstream side of the blocking wall 35 on the other side of the two screw holes. Transmission passages are formed at the upper side and the lower side of the barrier wall so as to communicate with the downstream side of the barrier wall 33 on one side: the valve means for adjusting the cross sectional area of the passages 39, 41 is transferred. A multi-axis unidirectional rotary extruder rotating in the same direction with a kneading degree adjusting device, which is provided in each passage. Single screw extruder with one screw 12 fitted to the body and equipped with a kneading degree adjuster which is heated and kneaded while the raw material fed into the body bore of the body is advanced by the screw for extrusion. Where: the middle part of the screw is a circumferential portion smaller than the screw diameter of the screw: the blocking wall 33 is circumferentially provided with a small gap in the axial direction at a position corresponding to the circumferential portion of the screw in the body hole. Interlocked with the mold part: a transmission passage 39 is formed in the blocking wall for passing through the upstream side of the blocking wall and the downstream side in the body hole. The valve means 43 for adjusting the cross sectional area of the transmission passage is provided in the transmission passage. Single screw extruder having a kneading degree adjusting device characterized in that the. 4. The barrier wall (33) according to claim 3, wherein the blocking wall (33) is a spiral of threaded continuous and its torsional direction is determined so that the raw material moves forward as the screw rotates, and the continuous spiral of thread has two ends when viewed from the axial direction of the screw. And a valve means extending between the two ends of the helical continuous thread so as to overlap the circumference so as to overlap. It has a pair of screws 12 and 13 fitted to the extruder body and the raw material fed through the two screw holes in the body is heated and kneaded while being transported by the two screws and the screws interlock with each other to extrude the resin. In a multi-axial (two-strand) extruder with a kneading degree adjuster, which is rotated in the opposite direction, each screw has a columnar portion adjacent to the downstream side of the kneading portion and the diameter of the columnar portion is a screw. Smaller than the thread diameter of: The blocking walls 122, 124, 126, 128 are provided at the circumferential and axial positions of the screw with a small distance between them provided at the axial position of the screw corresponding to the circumferential portions of the two screw holes. Interlock with the circumference of the screw with a small gap in between and separate the two screw holes upstream and downstream. Locking arrangements: Transmission passages 112, 114, 116, 118 for upstream side of the blocking wall and downstream side of the body are formed at the upper side and the lower side of the blocking wall and each screw: a valve for regulating the cross sectional area of the transmission passage. Means (102, 104, 106, 108) is a multi-screw rotating extruder with a kneading degree adjuster, characterized in that provided in the transmission passage. It has a pair of screws 12 and 13 fitted to the extruder body and the raw material fed through the two screw holes in the body is heated and kneaded while being transported by the two screws and the screws interlock with each other to extrude the resin. In a multi-axial (two screw) extruder with a kneading degree adjuster, which rotates in the opposite direction, each screw has a columnar portion 12, 13 adjacent to the downstream side of the kneading portion and having a columnar portion. The diameter of is smaller than the thread diameter of the screw; The blocking walls 122 and 126 interlock with the circumferential portion of the screw with a small gap provided therebetween at a axial position of the screw corresponding to the circumferential portion in the two screw holes, and the two cranial screw holes are arranged upstream and downstream. Arranged to separate; The transmission passages 112 and 116 are formed in a portion of the barrier wall, and the portion of each screw is introduced so that the raw material moved to the barrier wall separating the two screw holes along the inner wall of the body flows into the transfer passage and flows out downstream of the barrier wall. Located at the top; And a valve means (102) for adjusting the cross sectional area of the delivery passage.

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