Extruder screw, extruder and extrusion process

Abstract

Extruder screw (21) for conveying a raw material while the raw material is being kneaded, comprising: a screw body (37) having an axis (O1) extending in a conveying direction of the raw material and rotating about the axis (O1); a conveying section (54) provided on an outer circumferential surface of the screw body (37) and comprising a screw flight (56), wherein the screw flight (56) is designed to convey the raw material along the axis (O1) of the screw body (37) when the screw body (37) is rotated; and a plurality of passages (60) provided in the screw body (37) which allow the raw material conveyed via the screw flight (56) to pass through these to the outer circumferential surface of the screw body (37), wherein the passages (60) are provided in positions that deviate from the axis (O1) of the screw body (37), wherein the passages (60) have an inlet and an outlet which are open to the outer circumferential surface of the screw body (37), and the inlet and the outlet are separated from each other along the axis (O1) of the screw body (37), wherein the raw material which flows through the inlet into the passages (60) is returned through the outlet to the outer circumferential surface of the screw body (37), wherein the screw body (37) has a barrier section designed to increase the pressure of the raw material by restricting the raw material flow using the screw flight (56), and the inlet is positioned upstream of the barrier section.

Description

Technical area

[0001] The embodiments described herein relate to an extruder screw for kneading a mixed raw material while applying a shearing action and an elongation action thereto, and also relate to an extruder and an extrusion method for producing a kneaded product using the extruder screw. State of the art

[0002] For example, when a raw material produced by blending a plurality of incompatible resin materials is kneaded by an extruder with its screw set at a speed of approximately 300 rpm, it is necessary to add a compatibilizer with an affinity or adhesive force to one or both of the blended components. However, even if the compatibilizer is used, the blended components are not dissolved at the molecular level, resulting in limitations in improving the performance or functionality of a kneaded product produced by the extruder.

[0003] To solve the above-mentioned problem, a batch-type high-shear forming device was developed, which can produce a kneaded product by kneading its raw materials at the nano-level without any additive such as the compatibilizer.

[0004] The batch-operated, high-shear forming device according to WO 2010 / 061872 A1 comprises a hinged screw accommodated in a cylinder. This screw has a design suitable for sufficiently kneading a raw material obtained from incompatible mixed resin materials within the screw.

[0005] Specifically, the screw has an axis extending in the conveying direction of the raw materials and is configured to rotate around the axis within the cylinder. A helical flight is formed on the outer circumference of the screw. The flight conveys the raw material fed to the proximal end of the screw toward the tip end of the screw. The raw material conveyed by the flight is filled into a gap between the tip end side of the screw and a sealing element that closes the open end of the cylinder.

[0006] The cochlea has a bore with an inner diameter of approximately 1 to 5 mm located essentially at its center. This bore extends along the axis of the cochlea. The upstream end of the bore opens toward the gap and the side of the cochlea's tip end. The downstream end of the bore is branched and opens toward the outer periphery of the cochlea's proximal end.

[0007] The raw material filled into the gap flows from the downstream end of the bore into the bore in accordance with the rotation of the screw, and is returned from the downstream end of the bore to the outer periphery of the proximal end of the screw. The returned raw material is transported back into the gap by the screw flight.

[0008] Since the screw is designed to be operated with feedback, the raw material fed to the screw is subject to a shearing effect during conveyance through the screw flight and thus to an elongation effect when passing through the bore.

[0009] As a result, the raw material is circulated through the enclosed space within the cylinder while subjected to gravity and elongation. Depending on the time required for this circulation of the raw materials, the macromolecular component of the raw materials undergoes nanodispersion, resulting in a kneaded product with a nanoscopic dispersion structure.

[0010] DE 24 54 785 A1 discloses a screw extrusion press for thermoplastics and the like, with a coaxial twin screw whose screw flights are designed to rotate in opposite directions, two raw material feeds assigned to the two screws and a common outlet opening assigned to both screws, characterized by a mixing chamber located in front of the outlet opening, into which the partial flows of the mass flows conveyed by the two screws are each introduced at opposite ends.

[0011] US 4,302,409 A discloses a method for dispersing a liquid additive in only a portion of a stream of thermoplastic material, comprising the following steps: (a) allowing the stream of thermoplastic material to flow into a channel with walls of substantially circular cross-section, in which a rotating mixer head is arranged, having in its surface a plurality of alternating lands and grooves, each of the lands and grooves having an upstream end and a downstream end, the lands alternating with the grooves and being arranged in pairs, each of the pairs having a land loosely spaced from the wall followed by a land closely spaced from the wall, the mixer head having an unobstructed internal passage arranged therein over a substantial portion of its final length, and a plurality of channels,connecting the elongated zones between the pairs of lands and the hollow inner passage, and (b) injecting the liquid additive into the channel at a location between the upstream and downstream ends of the lands and grooves.

[0012] Further prior art can be found in JP S52 - 72 573 U, which discloses an extruder that extrudes a thermoplastic, and in JP S57 - 72 838 A, which discloses a screw extruder for thermoplastics and a special screw cooling system. Description of the inventionTechnical problem

[0013] In the high-shear forming device mentioned above, a hole into which raw material flows, filled into a gap, is positioned along the axis of the screw. In this design, the inner wall of the screw, which defines the hole, rotates in accordance with the rotation of the screw, thereby stirring the raw material along the circumference of the hole as it passes through the hole.

[0014] As a result, the raw material passing through the hole is subjected to gravity caused by extensive mixing, as well as to elongation, making it difficult to universally express the kneaded state of the raw material. Accordingly, there is a need for improvement in optimizing the kneading conditions of the raw materials.

[0015] An object of the invention is to provide an extruder screw capable of causing raw materials passing through a passage in a screw body to be relatively free from being subjected to a shearing action, whereby the degree of kneading of the raw materials can be precisely controlled.

[0016] Another object is to provide an extruder capable of producing a kneaded product having a nanoscopic dispersion structure in which the macromolecular component of the raw materials is nano-dispersed, and also to provide an extrusion method for use in the extruder. Solution to the problem

[0017] The problem described above is solved by an extruder screw having the features of claim 1, by an extruder screw having the features of claim 5, by an extruder having the features of claim 8, and by an extrusion process having the features of claim 9.

[0018] Optional features and preferred embodiments can be found in the dependent claims. Advantageous effects of the invention

[0019] According to the invention, the inner passage of the screw body revolves around the screw axis instead of rotating around the axis. As a result, a raw material that has passed through the passage and returned to the outer peripheral surface of the screw body is relatively free from shearing and primarily experiences an elongation effect on the raw material.

[0020] This means that the section of the screw where the shearing action is exerted on the raw material and the section of the screw where the elongation action is exerted on the material are fixed, allowing the degree of kneading of the raw material to be precisely controlled. As a result, a kneaded product can be produced that has a nanoscopic dispersion structure in which the macromolecular component of the raw material is nano-dispersed. Brief description of the drawings Fig. 1 is a schematic perspective view showing a continuous high shear processing apparatus according to a first embodiment. Fig. 2 is a cross-sectional view showing a first extruder used in the first embodiment. Fig. 3 is a perspective view showing a state in which the two screws of a first extruder in the first embodiment are meshed with each other. Fig. 4 is a cross-sectional view of a third extruder used in the first embodiment. Fig. 5 is a cross-sectional view of a second extruder used in the first embodiment. Fig. 6 is a cross-sectional view of the second extruder of the first embodiment, showing a barrel and a screw used therein. Fig. 7 is a side view of the screw of the first embodiment. Fig. Figure 8 is a cross-sectional view taken along line F8-F8 of Fig. 6 is recorded. Fig. Figure 9 is a cross-sectional view taken along line F9-F9 of Fig. 6 is recorded. Fig. 10 is an expanded cross-sectional view of the second extruder of the first embodiment, showing a passage formed by three adjacent cylinders along the rotation axis. Fig. 11 is a side view showing the flow direction of a raw material with respect to the screw in the first embodiment. Fig. 12 is a schematic cross-sectional view showing the flow direction of the raw material used in the first embodiment when the screw is rotated. Fig. 13 is a schematic cross-sectional view showing a second extruder according to a modification of the first embodiment. Fig. 14 is a schematic cross-sectional view of the second extruder according to the modification of the first embodiment, showing a state where cylindrical parts are replaced. Fig. 15 is a cross-sectional view of a second extruder used in a second embodiment. Fig. 16 is a cross-sectional view of a second extruder used in a third embodiment. Fig. 17 is a cross-sectional view of the second extruder of the third embodiment, showing a barrel and a screw used therein. Fig. 18 is a cross-sectional view taken along the line F18-F18 of Fig. 17 is recorded. Fig. 19 is a perspective view showing a cylinder used in the third embodiment. Fig. 20 is an expanded cross-sectional view showing the structure of a passage formed in the main body of the screw in the third embodiment. Fig. 21 is a cross-sectional view showing the flow direction of an accepted raw material in the third embodiment when the screw is rotated. Fig. 22 is a schematic cross-sectional view of the second extruder of the third embodiment, showing the flow direction of the received raw material when the screw is rotated. Fig. 23 is a perspective view of a barrier according to a modification of the third embodiment. Fig. 24 is a side view of a screw used in a fourth embodiment. Fig. 25 is a cross-sectional view of a second extruder used in the fourth embodiment. Fig. 26 is a cross-sectional view of the second extruder of the fourth embodiment, showing a barrel and a screw used therein. Fig. 27 is a cross-sectional view taken along line F27-F27 of Fig. 26 is recorded. Fig. 28 is a perspective view of a cylinder used in the fourth embodiment. Fig. 29 is a perspective view of the cylinder shown from a direction indicated by the arrow F29 in Fig. 28 is specified. Fig. 30 is a side view showing a direction of a used raw material in the fourth embodiment when the screw is rotated. Fig. 31 is a schematic cross-sectional view of the second extruder of the fourth embodiment, showing the direction of the raw material used when the screw is rotated. Fig. 32 is a schematic cross-sectional view showing a screw body according to Modification 1 of the fourth embodiment. Fig. 33 is a schematic cross-sectional view showing a screw body according to Modification 2 of the fourth embodiment. Fig. 34 is a schematic cross-sectional view showing a screw body according to Modification 3 of the fourth embodiment. Fig. 35(A) is an expanded cross-sectional view showing section F35A of Fig. 34 shows, and Fig. 35(B) is a cross-sectional view taken along the line F35B-F35B of Fig. 35(A). Fig. 36(A) is an expanded cross-sectional view showing a section F36A of Fig. 34 shows, and Fig. 36(B) is a cross-sectional view taken along the line F36B-F36B of Fig. 36(A). Fig. 37 is a schematic cross-sectional view showing a screw body according to Modification 4 of the fourth embodiment. Fig. 38 is a schematic cross-sectional view showing a screw body according to Modification 5 of the fourth embodiment. Fig. 39 is a schematic cross-sectional view showing a screw body according to Modification 6 of the fourth embodiment. Fig. 40 is a cross-sectional view of a second extruder according to a fifth embodiment. Fig. 41 is a cross-sectional view of a second extruder according to a sixth embodiment. Fig. 42 is a cross-sectional view of a second extruder according to a seventh embodiment. Fig. 43 is a cross-sectional view of a second extruder according to an eighth embodiment. Embodiments for carrying out the invention[First Embodiment]

[0021] Referring to Fig. 1 to 12, a first embodiment will now be described.

[0022] Fig. Figure 1 shows the outline of a continuous high-shear processing device 1 according to the first embodiment. The high-shear processing device 1 comprises a first extruder 2, a second extruder 3, and a third extruder 4. The first extruder 2, the second extruder 3, and the third extruder 4 are connected in series.

[0023] The first extruder 2 is used to pre-knead, for example, two types of incompatible resin materials. The resin materials to be mixed are, for example, a methacrylate-based resin such as polymethyl methacrylate (PMMA) and a polycarbonate resin (PC). The two types of resin materials to be mixed are fed to the first extruder 2, for example, in the form of pellets.

[0024] In the embodiment, in order to increase the degree of kneading / fusion of the resin materials, a unidirectional rotating type biaxial kneading machine is used as the first extruder 2. Fig. 2 and Fig. 3 shows an example of the biaxial kneading machine. The biaxial kneading machine includes a housing 6 and two screws 7a and 7b housed in the housing 6. The housing 6 includes a cylindrical portion 8 having a shape obtained by combining two cylinders. The above-mentioned resin materials are continuously supplied to the cylindrical portion 8 via a feeding portion 9 provided at one end of the housing 6. The housing 6 also includes a heater for heating the resin materials supplied to the cylindrical portion 8.

[0025] The screws 7a and 7b are received in the cylindrical portion 8 in an engaging manner. The screws 7a and 7b are rotated in the same direction when they receive a torque from a motor (not shown). As shown in Fig. As shown in Figure 3, the screws 7a and 7b each have a feeding section 11, a kneading section 12, and a pumping section 13. The feeding section 11, the kneading section 12, and the pumping section 13 are arranged along the axes of the screws 7a and 7b.

[0026] The feeding section 11 has a helical screw flight 14. The screw flights 14 of the screws 7a and 7b are rotated in an intermeshing manner and feed the two kinds of resin materials supplied from the feeding section 9 to the kneading section 12.

[0027] The kneading section 12 has a plurality of discs 15 arranged along the axis of each of the screws 7a and 7b. The discs 15 of the screws 7a and 7b are rotated in opposite positions to thereby pre-knead the resin materials supplied via the feeding section 11. The kneaded resin materials are fed into the pumping section 13 in accordance with the rotation of the screws 7a and 7b.

[0028] The pump section 13 has screw flights 16. The screw flights 16 of the screws 7a and 7b are rotated in an intermeshing manner, whereby the previously kneaded resin is discharged via the discharge end of the housing 6.

[0029] In the biaxial kneading machine described above, the resin materials supplied to the feeding section 11 of the screws 7a and 7b are fused by the heat generated during the shearing action exerted in accordance with the rotation of the screws 7a and 7b and the heat of the barrel 6 heated by a heater. The resin fused through the preliminary kneading in the biaxial kneading machine provides a mixed raw material. This raw material is continuously supplied to the second extruder 3 via the discharge end of the barrel 6, as indicated by arrow A. Fig. 1 is specified.

[0030] When the mixed raw material is fed to the second extruder 3, it has already been melted by the pre-kneading in the first extruder 2 and is therefore flowable. This reduces the stress on the second extruder 3, which thoroughly kneads the mixed raw material.

[0031] The second extruder 3 is a part for producing a kneaded material with a nanoscopic dispersion structure in which the macromolecular component of the raw material is nano-dispersed. In the embodiment, a uniaxial extruder is used as the second extruder 3. The uniaxial extruder has a barrel 20 and a single screw 21. The screw 21 functions to repeatedly apply a shearing action and an elongation action to the molten raw material. The structure of the second extruder 3 will be described in detail later.

[0032] The third extruder 4 is a part for removing a gas component contained in the kneaded material discharged from the second extruder 3. In the embodiment, a uniaxial extruder is used as the third extruder 4. As shown in Fig. As shown in Fig. 4, the uniaxial extruder includes a barrel 22 and a single vent screw 23 housed in the barrel 22. The barrel 22 includes a straight cylindrical portion 24. The kneaded material ejected from the second extruder 3 is continuously fed into the cylindrical portion 24 through one axial end thereof.

[0033] The housing 22 has a vent port 25. The vent port 25 opens toward the axial center of the cylindrical portion 24 and is connected to a vacuum pump 26. Furthermore, the other end of the cylindrical portion 24 of the housing 22 is connected to a heating portion 27. The heating portion 27 has a discharge port 28 for discharging the kneaded material.

[0034] The vent screw 23 is housed in the cylindrical portion 24. The vent screw 23 is rotated in one direction by a torque transmitted from a motor (not shown). The vent screw 23 has a screw thread 29. The screw thread 29 rotates with the vent screw 23, whereby the kneaded material supplied to the cylindrical portion 24 is continuously supplied to the heating portion 27.

[0035] When the kneaded material reaches a position corresponding to the vent port 25, it is subjected to a vacuum pressure from the vacuum pump 26. As a result, gaseous substances and other volatiles are continuously removed from the kneaded material. The kneaded material, from which gaseous substances and other volatiles have been removed, is continuously discharged to the outside of the high-shear processing device 1 via the discharge port 28 of the heating section 27.

[0036] Next, the second extruder 3 is described in detail.

[0037] As in Fig. 5 and Fig. As shown in Figure 6, the barrel 20 of the second extruder 3 is a straight cylinder and is arranged horizontally. The barrel 20 is divided into a plurality of barrel elements 31.

[0038] Each housing element 31 has a cylindrical through-bore 32. The housing elements 31 are integrally coupled so that the through-bores 32 are arranged coaxially throughout. The through-bores 32 of the housing elements 31 cooperate with each other to form a cylindrical portion 33 within the housing 20. The cylindrical portion 33 extends along the axis of the housing 20.

[0039] A feed port 34 is formed in one axial end of the housing 20. The feed port 34 communicates with the barrel section 33 and continuously receives mixed raw material from the first extruder 2.

[0040] The housing 20 includes a heating device (not shown). The heating device adjusts the housing 20 to an optimal temperature for kneading the raw material. Furthermore, the housing 20 includes a coolant passage 35 through which a coolant, such as water or oil, flows. The coolant passage 35 is arranged around the cylinder portion 33. The coolant flows along the coolant passage 35 when the temperature of the housing 20 exceeds a predetermined upper limit, forcibly cooling the housing 20.

[0041] The other axial end of the housing 20 is cooled via a heating section 36. The heating section 36 has a discharge port 36a. The discharge port 36a is positioned on the axially opposite side of the housing 20 with respect to the feed port 34 and is connected to the third extruder 4.

[0042] As in Fig. As shown in Figures 5 to 7, the screw 21 includes a screw body 37. The screw body 37 of the embodiment includes a single rotating shaft 38 and a plurality of cylindrical members 39.

[0043] The rotary shaft 38 has a first shaft portion 40 and a second shaft portion 41. The first shaft portion 40 is located at the proximal end of the rotary shaft 38, as is one end of the housing 20. The first shaft portion 40 includes a connecting portion 42 and a stop portion 43. The connecting portion 42 is coupled to a drive source, such as a motor, via a coupling (not shown). The stop portion 43 is arranged coaxially with the connecting portion 42. The stop portion 43 has a larger diameter than the connecting portion 42. The second shaft portion 41 extends coaxially from one end of the stop portion 43 of the first shaft portion 40. The second shaft portion 41 extends substantially along the entire length of the housing 20 and has a distal end opposite the heating portion 36.

[0044] The second shaft portion 41 is a fixed cylindrical portion having a diameter smaller than that of the stop portion 43. As shown in Fig. 8 and Fig. As shown in Figure 9, a pair of keys 45a and 45b are attached to the peripheral surface of the second shaft portion 41. The keys 45a and 45b extend axially along the second shaft portion 41 and are offset from each other by 180° with respect to the circumference of the second shaft portion 41.

[0045] In addition, the screw body 37 has an axis O1. The axis O1 extends through the centers of the first and second shaft sections 40 and 41 and coincides with the axis of the rotating shaft 38.

[0046] As in Fig. As shown in Figures 6 to 10, the cylindrical members 39 are elements that define the outer diameter of the screw bodies 37 and are coaxially inserted around the second shaft portion 41. In the embodiment, the outer diameter D1 of all cylindrical members 39 is set identically.

[0047] Each cylindrical member 39 has end surfaces 39a at its axially opposite ends. Each end surface 39a is a flat surface perpendicular to the axis O1. A pair of keyways 47a and 47b are formed in the inner peripheral surface of each cylindrical member 39. The keyways 47a and 47b extend along the axis of each cylindrical member 39, are each offset by 180° with respect to the circumference of each cylindrical member 39, and open onto the opposite end surfaces 39a thereof.

[0048] Each cylindrical member 39 is inserted into the second shaft portion 41 from the distal end of the second shaft portion 41, with keyways 47a and 47b that engage with keys 45a and 45b of the second shaft portion 41. In the embodiment, a first collar 48 is inserted between a cylindrical member 39, which was first attached to the second shaft portion 41, and the end surface of the stopper portion 43 of the first shaft portion 40. After inserting all the cylindrical members 39 into the second shaft portion 41, a second collar 50 is fixed to the distal end surface of the second shaft portion 41 via a fixed worm 49.

[0049] The fixed worm 49 is an example of a fastening member, and the second collar 50 is an example of an end plate. By fastening the second collar 50 to the distal end surface of the second shaft portion 41, all of the cylindrical members 39 are tightened along the axis of the second shaft portion 41 between the first and second collars 48 and 50, thereby joining the end surfaces 39a of the adjacent cylindrical members 39 without a gap.

[0050] As a result, all cylindrical members 39 are coaxially coupled to each other on the second shaft portion 41, forming a segmented worm body 37 with a constant outer diameter. Furthermore, the rotating shaft 38 and the cylindrical members 39 are assembled in a one-piece structure, allowing the cylindrical members 39 to rotate about the axis O1 in accordance with the rotation of the rotating shaft 38.

[0051] In the embodiment, the cylindrical member 39 is not limited to being fixed to the rotary shaft 38 via keys 45a and 45b. For example, the cylindrical member 39 may be fixed to the rotary shaft 38 using a key as shown in Fig. 2, instead of keys 45a and 45b.

[0052] The screw 21 is accommodated in the cylindrical portion 33 of the housing 20. The screw body 37 of the screw 21 extends coaxially with the cylindrical portion 33, and a conveying passage 51 is formed between the outer peripheral surface of the screw body 37 and the inner peripheral surface of the cylindrical portion 33. As shown in Fig. 8 and Fig. 9, the discharge passage 51 has an annular cross section when viewed radially with respect to the cylindrical portion 33 and extends along the axis of the cylindrical portion 33. The connecting portion 42 and the stopper portion 43 of the rotary shaft 38 extend from one end of the housing 20 to the outside of the housing 20.

[0053] In the embodiment, when a torque is transmitted from the drive source to the worm 21, the worm 21 rotates counterclockwise as indicated by the arrow in Fig. 5, when viewed from the proximal end of the rotary shaft 38. Preferably, the speed of the worm 21 is set at 600 to 3000 rpm.

[0054] As in Fig. As shown in Figures 5 to 7 and 10, the screw body 37 has a plurality of conveying sections 54 for conveying raw materials and a plurality of barrier sections 55 for restricting the flow of raw materials. The conveying sections 54 and the barrier sections 55 are arranged alternately along the axis of the screw body 37 (that is, along the length of the screw body 37).

[0055] The conveying sections 54 have screw flights 56. The screw flights 56 protrude into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 56 form the outer peripheral surfaces of the conveying sections 54. The screw flights 56 are twisted to cooperate to convey raw materials from the distal end of the screw body 37 to the proximal end thereof when the screw 21 rotates counterclockwise. In other words, the screw flights 56 are twisted counterclockwise, like a left-handed screw.

[0056] The length of each conveying section 54 along the axis of the screw body 37 is appropriately determined in accordance with, for example, the types and / or kneading degrees of raw materials and / or the amount of a kneaded product per unit time. Furthermore, although the conveying sections 54 are regions where the screw flights 56 are formed at least on the outer peripheral surfaces of the cylindrical members 39, they are not limited to the regions between the starting and ending points of the screw flights 56.

[0057] That is, a portion of the outer peripheral surface of the cylindrical member 39 that deviates from the screw thread 56 can also be considered a conveying section 54. Furthermore, if a cylindrical spacer or collar is arranged adjacent to the cylindrical member 39 with a screw thread 56, it can also be included in the conveying section 54.

[0058] The barrier sections 55 have respective screw flights 57. The screw flights 57 protrude into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 57 form the outer peripheral surfaces of the barrier sections 55. The screw flights 57 are twisted to cooperate to convey raw materials from the proximal end of the screw body 37 to the distal end thereof when the screw 21 is rotated counterclockwise. In other words, the screw flights 57 are twisted clockwise, like a right-handed screw.

[0059] The pitch of the screw thread 57 is equal to or less than that of the screw thread 56. In addition, a slight clearance is ensured between the upper points of the screw threads 56 and 57 and the inner peripheral surface of the cylindrical portion 33 of the housing 20.

[0060] The length of the barrier portion 55 along the axis of the screw body 37 is appropriately determined in accordance with, for example, the types and / or kneading degrees of the raw materials and / or the amount of a kneaded product per unit time. The barrier portion 55 serves to block the flow of raw materials conveyed by the conveying portion 54. That is, the barrier portion 55 is disposed adjacent to the conveying portion 54 on a downstream side with respect to the conveying direction of the raw materials and is configured to prevent the raw materials conveyed by the conveying portion 54 from passing through the gap between the top point of the screw flight 57 and the inner peripheral surface of the cylindrical portion 33.

[0061] In the embodiment, the barrier portion 55 is disposed at the proximal end of the screw body 37, which corresponds to one end of the casing 20, and a discharge screw flight 58 is provided at the distal end of the screw body 37, which corresponds to the other end of the casing 20. The discharge screw flight 58 projects into the conveying passage 51 from the outer peripheral surface of the cylindrical member 39, which is disposed at the distal end of the screw body 37. The discharge screw flight 58 is spiraled to convey raw materials from the proximal end of the screw body 37 to the distal end thereof. The feed port 34 of the casing 20 is opposed to the axial center portion of the conveying portion 54, which is closest to the proximal end of the screw body 37.

[0062] In the embodiment, the screw flights 56, 57, and 58 project into the conveying passage 51 from a plurality of cylindrical members 39 having the same outer diameter D1. Thus, the outer peripheral surfaces of the cylindrical members 39 define the core diameter of the screw 21. The core diameter of the screw 21 is constant over the entire length of the screw 21.

[0063] As in Fig. As shown in Figures 5 to 7 and 10, the screw body 37 has a plurality of passages 60 extending along the axis of the screw body 37. The passages 60 are arranged at intervals along the axis of the screw body 37. Furthermore, in the axially central portion of the screw body 37, four passages 60 extending along the axis of the screw body 37 are arranged at intervals of 90° along the circumference of the screw body 37.

[0064] Referring to Fig. 6 and Fig. 10, assuming that one of the barrier sections 55 and two of the conveyor sections 54 sandwiched in one barrier section 55 form a unit, each passage 60 is formed in the three consecutive cylindrical members 39 corresponding to the one unit.

[0065] Specifically, the passages 60 are defined from the first to the third passage elements 61, 62, and 63, respectively. The first passage element 61 can be considered the inlet of the passage 60. The first passage element 61 is formed in the outer peripheral surface of the cylindrical member 39 corresponding to the conveying section 54, which is closer to the proximal end of the screw body 37 than the barrier section 55 unit by unit, as mentioned above. On the outer peripheral surface of the cylindrical member 39 corresponding to the conveying section 54, the open end of the first passage element 61 is arranged closer to the boundary of the adjacent barrier section 55, which is closer to the proximal end of the screw body 37 than the conveying section 54. In addition, the open end of the first passage element 61 deviates from the screw flight 56.

[0066] In the embodiment, the first through-hole element 61 is formed by performing a machining process on the outer peripheral surface of the cylindrical member 39, for example, using a drill. To this end, the first through-hole element 61 is a bore with a circular cross-section that extends radially into the cylindrical member 39 from the outer peripheral surface thereof so as to intersect the axis O1. The lower portion 61a of the first through-hole element 61 represents a slope resulting from the conical shape of the cylindrical member 39 being capped by the tip of the drill.

[0067] The second passage element 62 can be considered a main passage section through which raw materials circulate. The second passage element 62 extends parallel to the axis O1 of the screw body 37 in the three cylindrical members 39 corresponding to the conveying sections 54 and the barrier section 55. To this end, the second passage element 62 extends along the axis of the screw body 37 without branching and has a predetermined length.

[0068] How best in Fig. As shown in Figure 10, the second passage member 62 includes a first portion 65a formed in one of the three cylindrical members 39 near the proximal end of the screw body 37, a second portion 65b formed in the middle of the three cylindrical members 39, and a third portion 65c formed in one of the three cylindrical members 39 near the distal end of the screw body 37. The first portion 65a, the second portion 65b, and the third portion 65c are arranged coaxially along the axis of the screw body 37.

[0069] The first portion 65a of the second passage member 62 extends through the cylindrical member 39 along its axis and opens toward the end surface 39a of the cylindrical member 39 near the central cylindrical member 39. The end of the first portion 65a opposite the open end thereof is closed by the end wall 39b of the cylindrical member 39. In the embodiment, the first portion 65a of the second passage member 62 is formed by performing a machining process on the end surface 39a of the cylindrical member 39, for example, using a drill. Therefore, the first portion 65a is defined as a bore with a circular cross-section.

[0070] The second portion 65b of the second passage element 62 is formed by performing a machining process on the central cylindrical member 39, for example, using a drill. The second portion 65b extends through the central cylindrical member 39 along its axis and opens toward the opposite ends 39a of the central cylindrical members 39. For this purpose, the second portion 65b is defined as a bore with a circular cross-section.

[0071] The third portion 65c of the second passage member 62 extends through the cylindrical member 39 along its axis and opens toward the end surface 39a of the cylindrical member 39 adjacent to the central cylindrical member 39. The end of the third portion 65c opposite the open end thereof is closed by the end wall 39b of the cylindrical member 39. In the embodiment, the third portion 65c of the second passage member 62 is formed by performing a machining process on the end surface 39a of the cylindrical member 39, for example, using a drill. Therefore, the third portion 65c is defined as a bore with a circular cross-section.

[0072] As in Fig. 6 and Fig. 10, the open end of the first portion 65a, the open end of the second portion 65b, and the open end of the third portion 65c are coaxially adjacent to each other so as to communicate with each other when the three adjacent cylindrical members 39 are tightened along the axis of the rotary shaft 38.

[0073] The third passage member 65c can be considered the outlet of the passage 60. The third passage member 65c opens onto the outer peripheral surface of the cylindrical members 39 corresponding to the conveying section 54, which is closer to the distal end of the screw body 37 than the barrier section 55, unit by unit, as mentioned above. On the outer peripheral surface of the cylindrical member 39 corresponding to the conveying section 54, the open end of the third passage member 63 is located close to the boundary of the adjacent barrier section 55, which is closer to the distal end of the screw body 37 than the conveying section 54. Furthermore, the open end of the third passage member 65c deviates from the screw flight 56.

[0074] Furthermore, in the embodiment, the third through-passage element 63 is formed by performing a machining process on the outer peripheral surface of the cylindrical member 39, for example, using a drill. Therefore, the third through-passage element 63 is a bore with a circular cross-section and extends radially from the outer peripheral surface of the cylindrical member 39. The lower portion 63a of the third through-passage element 63 represents a slope resulting from the conical shape of the cylindrical member 39 being capped by the tip of the drill.

[0075] The open ends of the first and third passage elements 61 and 63 are separated from each other along the axis of the screw body 37 by the two conveying sections 54 and the one interposed barrier section 55. In other words, the shape of the surface of the screw body 37 varies between the open ends of the first and third passage elements 61 and 63.

[0076] As in Fig. As shown in Figure 10, the end of the first portion 65a of the second passage member 62, which is opposite the open end, is connected to the first passage member 61 within the cylindrical member 39. The first passage member 61 and the first portion 65a of the second passage member 62 communicate with each other while maintaining their circular cross sections. Furthermore, the end of the first portion 65a of the second passage member 62 is connected to the first passage member 61 at a position deviating from the conical lower portion 61a of the first passage member 61. Alternatively, the first portion 65a of the second passage member 62 may be connected to the lower portion 61a of the first passage member 61.

[0077] Accordingly, the first passage member 61 can be considered as a first upright portion erected radially with respect to the cylindrical member 39 from the end of the first portion 65a of the second passage member 62 so as to open toward the outer peripheral surface of the screw body 37.

[0078] The end of the third portion 65c of the second passage member 62, opposite the open end, is connected to the third passage member 63 within the cylindrical member 39. The passage member 63 and the third portion 65c of the second passage member 62 communicate with each other, maintaining their circular cross-sections. Furthermore, the end of the third portion 65c of the second passage member 62 is connected to the third passage member 63 at a position different from the conical lower portion 63a of the third passage member 63. Alternatively, the third portion 65c of the second passage member 62 may be connected to the lower portion 63a of the third passage member 63.

[0079] Accordingly, the third passage member 63 can be considered as a second upright portion erected radially with respect to the cylindrical member 39 from the end of the third portion 65c of the second passage member 62 so as to open toward the outer peripheral surface of the screw body 37.

[0080] In addition, the middle section of the screw body 37, the first passage element 61, which is used as the inlet of a passage 60, and the third passage element 63, which is used as the outlet of another adjacent passage 60, communicate with the conveying passage 51 between the two adjacent barrier sections 55.

[0081] Since the passage 60 is also provided in the cylindrical member 39, it runs eccentrically with respect to the axis O1 of the screw body 37. For this reason, the passage 60 rotates around the axis O1 when the screw body 37 rotates.

[0082] It is recommended to set the inner diameter of the bore forming the second passage member 62, for example, to not less than 1 mm and less than 6 mm, and preferably to a range of 1 mm or more to 5 mm or less. The inner diameter of the second passage member 62 is smaller than that of the first passage member 61 as the inlet. The cross section of the second passage member 62 is much smaller than the cross section of the discharge passage 51 extending radially with respect to the cylindrical portion 33.

[0083] According to the embodiment, the cylindrical member 39 has a cylindrical wall 66 that defines the shape of the bore forming the first to third passage members 61, 62, and 63. The first to third passage members 61, 62, and 63, surrounded by the wall 66, are each a hollow space for allowing only raw materials to pass through and do not include a member for providing the screw body 37. The wall 66 revolves around the axis O1 instead of rotating thereabout as the screw body 37 rotates.

[0084] In the embodiment, when the screw 21 is disassembled by removing the cylindrical members 39 from the rotary shaft 38, the cylindrical members 39, which are part of the screw flights 56, 57 and 58, can be referred to as screw elements.

[0085] Also, in the embodiment, the screw body 37 of the screw 21 is formed by sequentially mounting the cylindrical members 39 as screw elements on the rotating shaft 38. This structure allows the conveying sections 54 and the barrier sections 55 to be exchanged or combined, for example, in accordance with the kneading degree of the raw materials, and facilitates exchange / combination work.

[0086] In addition, by tightening the cylindrical members 39 along the axis of the rotary shaft 38 to firmly fix the adjacent end surfaces 39a of the cylindrical members 39 to each other, the second passage member (main passage portion) 62 of the passage 60 is formed, wherein the first passage member (inlet) 61 closely communicates with the third passage member (outlet) 63 via the second passage member 62.

[0087] Due to the above-mentioned structure, to form the passage 60 in the screw body 37, it is sufficient to form the single cylindrical member 39, which is substantially shorter than the entire length of the screw body 37. This makes the formation and handling of the passage 60 very simple.

[0088] In the continuously operated high-shear processing device 1 configured as above, the first extruder 2 first kneads a plurality of resin materials. The resulting resin, fused by this kneading, is a mixed raw material with fluidity and is continuously fed to the feed port 34 of the second extruder 3.

[0089] The mixed raw material supplied to the second extruder 3 is guided to the outer peripheral surface of the conveying section 54 which is closest to the proximal end of the screw 21, as shown by arrow B in Fig. 11. Since the screw 21 rotates counterclockwise when viewed from the proximal end of the rotary shaft 38, the flight 56 ​​of the conveying section 54 conveys the raw material supplied through the feed port 34 to the adjacent barrier section 55 positioned close to the proximal end of the screw body 37, as indicated by the solid arrows in Fig. 11. That is, the screw flight 56 ​​guides the raw material fed through the feed port 34 to the proximal end of the screw body 37.

[0090] At this time, the raw material receives a shearing action caused by the difference in rotational speed between the screw flight 56 ​​rotating in the conveying passage 51 and the inner peripheral surface of the cylindrical portion 33, and is also stirred by the slightly wound screw flight 56. As a result, the raw material is thoroughly kneaded, and the dispersion of the macromolecular component of the raw material progresses.

[0091] The sheared raw material is conveyed along the conveying passage 51 and reaches the boundary of the conveying section 54 and the barrier section 55. The flight 57 of the barrier section 55 is wound clockwise to allow the raw material to be conveyed from the proximal end to the distal end of the screw body 37 when the screw 21 rotates counterclockwise, thereby blocking the raw material fed via the flight 56. In other words, when the screw 21 rotates counterclockwise, the flight 57 of the barrier section 55 restricts the flow of raw material fed via the flight 56 ​​and prevents it from passing through a gap between the outer peripheral surface of the barrier section 55 and the inner peripheral surface of the cylindrical section 33.

[0092] This increases the pressure of the raw material at the boundary between the conveying section 54 and the barrier section 55. In particular, Fig. 12, the filling levels of the raw material in positions corresponding to the conveying sections 54 of the screw body 37 in the conveying passage 51 are indicated by gradations. That is, the deeper the gradation, the higher the filling level. As can be seen from Fig. As can be seen from Figure 12, the following applies in the conveying passage 51: the closer to the barrier section 55, the higher the fill level of the raw material. Furthermore, in a position closest to the barrier section 55, the fill level of the material is 100%.

[0093] As a result, a material container R with a filling level of 100% is designed in the position closest to the barrier section 55. In the material container R, the pressure of the raw material is increased because it is blocked by the barrier section. The increased pressure raw material flows from the first passage element 61 of the passage 60 to the second passage element 62 thereof, as indicated by the dashed arrows in Fig. 11 and Fig. 12 is shown.

[0094] The cross-section of the second passage member 62 is smaller than the cross-section of the conveying passage 51, which extends radially with respect to the cylindrical portion 33. In other words, because the inner diameter of the second passage member 62 is substantially smaller than the outer diameter of the screw body 37, the raw material is drastically constricted as it passes through the second passage member 62, exerting an elongation effect on the raw material.

[0095] In addition, since the cross section of the second passage member 62 is sufficiently smaller than that of the conveying passage 51, the material container R in front of the barrier section 55 will not shrink even though the raw material R collected in the material container R flows into the passage 60. Accordingly, even if the raw material flow guided into the barrier section 55 by the screw flight 56 ​​is reduced to a certain extent, the reduction in the flow can be compensated by the raw material collected in the material container R. Thus, the raw material is always stably supplied to the passage 60.

[0096] The raw material passed through the second passage member 62 is returned to the conveying section 54 near the distal end of the screw body 37 through the third passage member 63, as shown by the solid arrows in Fig. 12. The returned raw material is conveyed through the screw flight 56 ​​of the conveying section 54 toward the proximal end of the screw body 37 and is again subjected to a shearing action during this conveying. The raw material subjected to the shearing action flows from the first passage element 61 of the passage 60 into the second passage element 62 thereof and is again subjected to an elongation action as it passes through the second passage element 62.

[0097] In the embodiment, a plurality of conveying sections 54 and a plurality of barrier sections 55 are alternately arranged along the axis of the screw body 37, and a plurality of passages 60 are arranged at intervals along the axis of the screw body 37. Accordingly, the raw material introduced into the screw body 37 through the feed port 34 is continuously conveyed from the proximal end of the screw body 37 to the distal end thereof while being alternately subjected to the shearing action and the elongation action, as indicated by the arrows in Fig. 10 and Fig. 11. As a result, the degree of kneading of the raw material is increased, thereby promoting the dispersion of the macromolecular component of the raw material.

[0098] The second passage elements 62 of the passages 60 are open to the outer peripheral surface of the screw body 37 through the respective first passage elements 61 and the respective third passage elements 63. Therefore, in each passage 60, the raw material that has flowed into the corresponding second passage element 62 through the corresponding first passage element 61 is always returned to the outer peripheral surface of the screw body 37 through the corresponding third passage element 63. This means that the respective raw materials in the plurality of passages 60 are not mixed.

[0099] This structure prevents excessive kneading of the raw material and allows adequate kneading to achieve a desired degree of kneading.

[0100] The raw material that has reached the distal end of the screw body 37 and is a sufficiently kneaded material is supplied to a gap between the cylindrical portion 33 and the heating portion 36 through the outlet 63 of the passage 60 closest to the heating portion. Furthermore, the kneaded material is continuously supplied to the third extruder 4 from the discharge port 36a of the heating portion 36.

[0101] In the third extruder 4, as already described, a gaseous substance and / or other volatile components of the kneaded material are continuously removed from the kneaded material. The kneaded material, from which the gaseous substance and / or other volatile components have been removed, is continuously discharged to the outside of the high-shear processing device 1 through the discharge port 28 of the heating section 27. The discharged kneaded material is immersed in cooling water stored in a reservoir. As a result, the kneaded material is forcibly cooled to thereby obtain a desired molded resin piece.

[0102] In the second extruder 3, the raw material fed from the first extruder 2 is conveyed along the axis of the screw body 37, repeatedly in reverse. During this conveying, the raw material is repeatedly subjected to shearing and elongation. In other words, since the raw material does not circulate repeatedly in the same position on the outer peripheral surface of the screw body 37, it can be continuously fed from the second extruder 3 to the third extruder 4.

[0103] As a result, a sufficiently kneaded material can be produced continuously, thereby remarkably improving the production efficiency of kneaded material compared with the batch-operated high-shear forming device.

[0104] Furthermore, in the embodiment, since the resin pre-kneaded by the first extruder 2 is continuously supplied to the second extruder 3, the resin flow is prevented from being temporarily stopped in the first extruder 2. This prevents a change in the temperature, viscosity, or phase of the resin due to accumulation of the pre-kneaded resin in the first extruder 2. Therefore, a raw material of uniform quality can always be supplied from the first extruder 2 to the second extruder 3.

[0105] In the first embodiment, the passage 60 for applying the elongation effect to the raw material extends along the axis of the screw body 37 in an eccentric position with respect to the rotation axis O1 of the screw body 37, thereby orbiting around the axis O1. In other words, the cylindrical wall 66 defining the passage 60 orbits around the axis O1 instead of rotating around the axis O1.

[0106] For this reason, when the raw material passes through passage 60, it is not significantly agitated, even though it experiences centrifugal force. The raw material passing through passage 60 and returning to the conveying section 54 does not experience much shearing action, but primarily the elongation effect.

[0107] For this purpose, in the first embodiment, the respective sections of the screw 21 in which the shearing action and the elongation action are applied to the raw material can be precisely defined. This represents a very advantageous configuration for determining the degree of kneading of the raw material, and the degree of kneading can be precisely controlled. As a result, a kneaded material can be produced that has a nanoscopic dispersion structure in which the macromolecular component of the raw material is nano-dispersed.

[0108] In addition, because all passages 60 are eccentric with respect to the axis O1, the elongation effect can be uniformly applied to portions of the raw material passing through the passages 60. This means that fluctuations in the kneading conditions between the passages 60 can be overcome, thereby enabling uniform kneading.

[0109] In the first embodiment, since the cylindrical members 39 have the same outer diameter D1, the conveying passage 51 has a uniform annular cross-section along the entire length of the screw body 37. Accordingly, when the shearing and elongation actions are repeatedly applied to the raw material through the conveying passage 51, the passage 51 can enable these actions to be sequentially and smoothly applied to the raw material, thereby further achieving uniform kneading.

[0110] Furthermore, in the first embodiment, the screw 21 is formed by the combination of the conveying sections 54, the barrier sections 55, and the passages 60 and does not include a plasticizing section used in the conventional uniaxial extruder. This allows the second extruder 3 to be operated easily. [Modification of the first embodiment]

[0111] Fig. 13 and Fig. 14 show a modification of the first embodiment.

[0112] When changing to Fig. 13, the screw flight 57 constituting the barrier portion 55 and a part of the screw flight 56 ​​constituting the conveying portion 54 are continuously formed on the outer peripheral surface of the cylindrical member 39 provided with the second portion 65b of the second passage member 62. That is, the second portion 65b of the second passage member 62 is disposed in the cylindrical member 39, in which two types of screw flights 56 and 57 are formed.

[0113] In this construction, if an associated cylindrical member 68 in which the screw thread 57 for the barrier section 55 is formed on the entire outer peripheral surface, as shown in Fig. 14, when the cylindrical member 39 is provided with the second portion 65b of the second passage member 62, this may be replaced by the above-mentioned cylindrical member 39 having two kinds of screw threads 56 and 57.

[0114] The ratio of an area occupied by screw flights 56 for the conveying sections 54 and an area occupied by screw flights 57 for the barrier sections 55 can vary in accordance with, for example, the degree of kneading of the raw material within the entire length of the three cylindrical members 39, 68 included in the passages 60. [Second embodiment]

[0115] Fig. Figure 15 shows a second embodiment. The second embodiment differs from the first embodiment with respect to the rotary shaft 38 of the screw 21. The other structures of the second extruder 3 are essentially the same as in the first embodiment. Therefore, in the second embodiment, similar elements to those in the first embodiment are provided with corresponding reference numerals and will not be described in detail.

[0116] As in Fig. As shown in Figure 15, a coolant passage 71 is formed within the rotary shaft 38. The coolant passage 71 extends coaxially with the rotary shaft 38 along the axis O1 thereof. One end of the coolant passage 71 is connected to the outlet port 73 through a rotary joint 72 at the connecting portion 42. The other end of the coolant passage 71 is fluid-tightly sealed by the distal end of the rotary shaft 38.

[0117] A coolant introduction pipe 74 is coaxially inserted into the coolant passage 71. One end of the coolant introduction pipe 74 is connected to the inlet port 75 through the swivel joint 72. The other end of the coolant introduction pipe 74 is open to the inside of the coolant passage 71, close to the other end of the coolant passage 71.

[0118] In the second embodiment, a coolant such as water or oil is introduced from the inlet port 75 into the coolant passage 71 through the rotary joint 72 and the coolant introduction pipe 74. The coolant introduced into the coolant passage 71 is returned to the connecting portion 42 of the rotary shaft 38 through a gap between the inner peripheral surface of the coolant passage 71 and the outer peripheral surface of the coolant introduction pipe 74, and is returned to the outlet port 73 via the rotary joint 72.

[0119] In the second embodiment, the coolant flows along the axis of the rotating shaft 38, cooling the screw body 37. Therefore, the temperature of the screw body 37 contacting the raw materials can be appropriately adjusted, thereby preventing resin deterioration, changes in resin viscosity, etc., caused by increases in the temperature of the raw materials. [Third Embodiment]

[0120] Fig. 16 to 22 show a third embodiment. The third embodiment differs from the first embodiment with respect to the screw body 37 of the screw 21. The other structures of the second extruder 3 are essentially the same as in the first embodiment. Therefore, in the third embodiment, similar elements to those in the first embodiment are provided with corresponding reference numerals and will not be described in detail.

[0121] As in Fig. 16 and Fig. 17, a plurality of cylindrical members 39 constituting the screw body 37 are fixed between the first and second collars 48 and 50 along the axis of the second shaft portion 41, whereby the end surfaces 39a of the adjacent cylindrical members 39 are connected to each other without a gap.

[0122] The screw body 37 has a plurality of conveying sections 81 for conveying the raw materials and a plurality of barrier sections 82 for restricting the flow of raw materials. The conveying sections 81 and the barrier sections 82 are arranged alternately along the axis of the screw body 37.

[0123] As in Fig. 17 and Fig. As shown in Fig. 19, the conveying sections 81 have respective screw flights 84. The screw flights 84 project into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 84 form the outer peripheral surfaces of the conveying sections 81. The screw flights 84 are twisted to cooperate to convey the raw materials from the proximal end of the screw body 37 to the distal end thereof when the screw 21 is rotated counterclockwise. In other words, the screw flights 84 are twisted clockwise, like a right-handed screw. The length of the conveying section 81 along the axis of the screw body 37 is approximately determined in accordance with, for example, the types and / or kneading degrees of raw materials and / or the amount of a kneaded product per unit time.In addition, although the conveying sections 81 are regions where the screw flights 84 are formed at least on the outer peripheral surfaces of the cylindrical members 39, they are not limited to regions between the starting point and the end point of the screw flights 84.

[0124] In other words, portions of the outer peripheral surfaces of the cylindrical members 39 that deviate from the screw flights 84 can also be considered conveyor sections 81. Furthermore, if a cylindrical spacer or collar is provided adjacent to a cylindrical member 39 with a screw flight 84, it can also be included in the conveyor section 81.

[0125] The barrier sections 82 have respective screw flights 85. The screw flights 85 protrude into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 85 form the outer peripheral surfaces of the barrier sections 82. The screw flights 85 are spiraled to cooperate to convey the raw materials from the distal end of the screw body 37 to the proximal end thereof when the screw 21 is rotated counterclockwise. In other words, the screw flights 85 are spiraled clockwise, like a left-handed screw.

[0126] The pitch of the screw flight 85 of the barrier section 82 is equal to or less than that of the screw flight 84 of the conveying section 81. In addition, a slight clearance is ensured between the upper regions of the screw flights 84 and 85 and the inner peripheral surface of the cylindrical section 33 of the housing 20.

[0127] The length of the barrier section 82 along the axis of the screw body 37 is approximately determined in accordance with, for example, the types and / or kneading degrees of the raw materials and / or the amount of kneaded product per unit time. The barrier section 82 serves to block the flow of the raw material fed from the conveying section 81. That is, the barrier section 82 is disposed adjacent to the conveying section 81 on the downstream side with respect to the conveying direction of the raw materials and is designed to prevent the raw material fed from the conveying section 81 from passing through the gap between the upper portion of the screw flight 85 and the inner peripheral surface of the cylindrical section 33.

[0128] For this purpose, in the second extruder 3 of the embodiment, it is assumed that the flow of the raw materials is shut off at the barrier portion 82, and the raw materials do not pass through the gap between the outer peripheral surface of the barrier portion 82 and the inner peripheral surface of the cylindrical portion 33.

[0129] According to the embodiment, a plurality of conveying sections 81 are arranged continuously along the axis of the screw body 37 at the proximal end of the screw body 37. The feed port 34 of the housing 20 is located opposite the axially central portion of a conveying section 81 at the proximal end of the screw body 37. Similarly, a plurality of conveying sections 81 are arranged continuously along the axis of the screw body 37 at the distal end of the screw body 37.

[0130] As in Fig. 17 and Fig. As shown in Fig. 19, in the central portion of the screw body 37, the screw flight 84 constituting the conveying portion 81 and the screw flight 85 constituting the barrier portion 82 are provided sequentially on the outer peripheral surface of a corresponding cylindrical member 39. That is, two types of screw flights 84 and 85 are arranged axially sequentially on a cylindrical member 39. The screw flight 85 constituting the barrier portion 82 is arranged closer to the distal end of the screw body 37 than the screw flight 84 constituting the conveying portion 81.

[0131] In this embodiment, the screw flights 84 and 85 also protrude into the conveying passage 51 from a plurality of cylindrical members 39 with the same outer diameter D1. Thus, the outer circumferential surfaces of the cylindrical members 39 define the core diameter of the screw 21. The core diameter of the screw 21 is constant over the entire length of the screw 21.

[0132] As in Fig. As shown in Figures 16 to 20, the screw body 37 has a plurality of passages 86 extending along the axis of the screw body 37. The passages 86 are arranged on a line parallel to the axis of the screw body 37. Each passage 86 is formed in two consecutive cylindrical members 39, on which two types of screw flights 84 and 85 are formed. Specifically, each passage 86 is formed by the first to third passage elements 87, 88, and 89.

[0133] The first passage element 87 can be considered the inlet of the passage 86. The first passage element 87 opens toward the outer peripheral surface of one of the two consecutive cylindrical members 39. The open end of the first passage element 87 is positioned at the boundary of the conveying section 81 and the barrier section 82 and deviates from the screw flight 84 of the conveying section 81 and the screw flight 85 of the barrier section 82.

[0134] Furthermore, in the embodiment, the first through-passage element 87 is formed by performing a machining process on the outer peripheral surface of one of the cylindrical members 39 using, for example, a drill. To this end, the first through-passage element 87 is a bore with a circular cross-section and extends radially into the one cylindrical member 39 from the outer peripheral surface thereof, intersecting the axis O1. The lower portion 87a of the first through-passage element 87 forms a slope resulting from capping the cylindrical member 39 in the shape of a cone with the tip of the drill.

[0135] The second passage element 88 can be considered a main passage section through which raw materials circulate. The second passage element 88 extends parallel to the axis O1 of the screw body 37 in the two consecutive cylindrical members 39. To this end, the second passage element 88 extends along the axis of the screw body 37 without branching and has a predetermined length.

[0136] How best in Fig. 20, the second passage member 88 has a first portion 91a formed in one of the cylindrical members 39 and a second portion 91b formed in the other cylindrical member 39.

[0137] The first portion 91a of the second passage member 88 extends along the axis of one cylindrical member 39 and opens toward the end surface 39a of one cylindrical member 39 near the other cylindrical member 39. The end of the first portion 91a opposite the open end is closed by the axially central portion of the one cylindrical member 39. According to the embodiment, the first portion 91a of the second passage member 88 is formed by performing a machining process on the one cylindrical member 39 from the end surface 39a side thereof using, for example, a drill. To this end, the first portion 91a is defined as a bore having a circular cross-section.

[0138] The second portion 91b of the second passage member 88 extends along the axis of the above-mentioned further cylindrical member 39 and opens to the end surface 39a of the further cylindrical member 39 close to the above-mentioned one cylindrical member 39. The end of the second portion 91b opposite the open end thereof is closed in the one further cylindrical member 39.

[0139] In the embodiment, the second portion 91b of the second through member 88 is formed by performing a machining process on the further cylindrical member 39 from the end surface 39a thereof using, for example, a drill. To this end, the second portion 91b is defined as a bore with a circular cross-section, like the first portion 91a.

[0140] How best in Fig. 17 and Fig. 20, when two adjacent cylindrical members 39 are mounted along the axis of the rotary shaft 38, the open end of the first portion 91a and the open end of the second portion 91b abut coaxially so as to communicate with each other.

[0141] The third passage element 89 can be considered the outlet of the passage 86. The third passage element 89 opens onto the outer peripheral surface of the other of the two adjacent cylindrical members 39. The open end of the third passage element 89 is located at the upstream end of the conveying section 81 and deviates from the screw flight 84 of the conveying section 81. As a result, the open ends of the first and third passage elements 87 and 89 are arranged separated from each other along the axis of the screw body 37, with the barrier section 82 interposed therebetween.

[0142] Furthermore, in the embodiment, the third through-passage element 89 is formed by performing a machining process on the outer peripheral surface of the further cylindrical members 39 using, for example, a drill. To this end, the third through-passage element 89 is a bore with a circular cross-section and extends radially into the further cylindrical member 39 from the outer peripheral surface thereof, intersecting the axis O1. The lower portion 89a of the third through-passage element 89 forms a slope resulting from the conical shape of the cylindrical member 39 being capped by the tip of the drill.

[0143] As in Fig. As shown in Fig. 20, the end of the first portion 91a of the second passage member 88, which is opposite to the open end thereof, is coupled to the first passage member 87 within the one cylindrical member 39. The first passage member 87 and the first portion 91a of the second passage member 88 communicate with each other while maintaining their circular cross-section. Moreover, the first portion 91a of the second passage member 88 is coupled to the first passage member 87 at a position deviating from the conical lower portion 87a of the first passage member 87. In contrast, the first portion 91a of the second passage member 88 is coupled to the lower portion 87a of the first passage member 87.

[0144] In view of the above description, the first passage member 87 can also be regarded as a first standing portion erected from one end of the first portion 91a of the second passage member 88 radially with respect to the cylindrical member 39 and opening toward the outer peripheral surface of the screw body 37.

[0145] The end of the second portion 91b of the second passage member 88, opposite its open end, is coupled to the third passage member 89 within the further cylindrical member 39. The third passage member 89 and the second portion 91b of the second passage member 88 communicate with each other, maintaining their circular cross-sections. Furthermore, the second portion 91b of the second passage member 88 is coupled to the third passage member 89 at a position different from the conical lower portion 89a of the third passage member 89. In contrast, the second portion 91b of the second passage member 88 is coupled to the lower portion 89a of the third passage member 89.

[0146] For this purpose, the third passage element 89 can also be considered as a second standing section which is set up radially from one end of the second section 91b of the second passage element 88 with respect to the cylindrical member 39 and opens towards the outer peripheral surface of the screw body 37.

[0147] According to the embodiment, since the passage 86 is provided inside the cylindrical member 39, the passage 86 extends eccentrically with respect to the axis O1 of the screw body 37. For this purpose, the passage 86 rotates around the axis O1 when the screw body 37 rotates.

[0148] The inner diameter of the bore forming the second passage member 88 is set, for example, to 1 mm or more and less than 6 mm, and preferably to 1 mm or more and 5 mm or less. Furthermore, the inner diameter of the second passage member 88 is smaller than that of the first passage member 87 used as an inlet. The cross section of the second passage member 88 is set substantially smaller than the cross section of the discharge passage 51 extending radially with respect to the cylindrical portion 33.

[0149] According to the embodiment, the cylindrical members 39 have cylindrical walls 92 that define the bores forming the first to third passage elements 87, 88, and 89. The first to third passage elements 87, 88, and 89, surrounded by the walls 92, are cavities that allow only raw materials to pass through and do not contain any elements forming the screw bodies 37. Furthermore, the wall 92 revolves around the axis O1 instead of rotating around the axis O1 when the screw body 37 rotates.

[0150] In addition, in the embodiment, when a plurality of cylindrical members 39 provided with the screw threads 84 and 85 are removed from the rotary shaft 38, each cylindrical member 39 provided with at least the first passage member 87 or the third passage member 89 and the second passage member 88 formed therein can also be regarded as a screw member.

[0151] In the above-described structure, the raw material obtained by mixing by the first extruder 2 and having a flowability is continuously fed to the conveying passage 51 through the feed port 34 of the second extruder 3. The raw material fed to the second extruder 3 is guided to the outer peripheral surface of one of the conveying sections 81 located at the proximal end of the screw body 37, as indicated by arrow C in Fig. 21. Since the screw 21 is rotated counterclockwise, as viewed from the proximal end of the rotary shaft 38, the screw flight 84 of the conveying section 81 conveys the raw material introduced through the feed port 34 toward the distal end of the screw body 37, as indicated by the solid arrows in Fig. 21 is indicated.

[0152] At this time, a shearing action caused by the speed difference between the screw flights 84 rotating in the conveying passage 51 and the inner peripheral surface of the cylindrical portion 33 is applied to the raw material, and the raw material is stirred by slightly rotating the screw flights 84. As a result, the raw material is thoroughly kneaded, and the dispersion of the macromolecular component of the raw material progresses.

[0153] The raw material subjected to the shearing action moves along the conveying passage 51 and reaches the boundary of the conveying section 81 and the barrier section 82. Since the screw flight 85 of the barrier section 82 is designed to convey the raw material from the distal end side of the screw body 37 to the proximal end side thereof, when the screw 21 rotates counterclockwise, it blocks the raw material supplied via the screw flight 84.

[0154] That is, when the screw 21 is rotated counterclockwise, the flight 85 of the barrier portion 82 restricts the flow of the raw material fed via the flight 84 of the conveying portion 81 and prevents the raw material from passing through the gap between the outer peripheral surface of the barrier portion 82 and the inner peripheral surface of the cylindrical portion 33.

[0155] As a result, the pressure of the raw material increases at the boundary of the conveying section 81 and the barrier section 82. In particular, Fig. 22 using a gradation, the filling ratio of the raw material in a section of the conveying passage 51 corresponding to the conveying section 81, ie, the deeper the color, the higher the filling ratio of the raw material. As clearly shown in Fig. 22, in the conveying passage 51, the filling ratio of the raw material is higher at a position closer to the barrier section 82 and is 100% before the barrier section 82.

[0156] Thus, a material container R with a material filling ratio of 100% is formed in front of the barrier section 82. In the material container R, the pressure of the raw material is increased because the flow of the raw material is blocked. The increased pressure raw material flows into the second passage element 88 through the first passage element 87 of the passage 86, which opens towards the boundary of the conveying section 81 and the barrier section 82, as shown by the dashed arrows in Fig. 21 and Fig. 22. The raw material that has flowed into the second passage member 88 flows through the second passage member 88 from the proximal end side of the screw body 37 to the distal end side thereof.

[0157] The cross-section of the second passage member 88 is smaller than that of the conveying passage 51, which is parallel to the cross-section of the cylindrical portion 33. In other words, because the inner diameter of the second passage member 88 is substantially smaller than the outer diameter of the screw body 37, the raw material is significantly restricted and elongated as it passes through the second passage member 88.

[0158] In addition, since the cross section of the second passage member 88 is substantially smaller than that of the conveying passage 51, the material container R in front of the barrier section 82 does not shrink even though the raw material collected in the material container R flows into the passage 86. Accordingly, even if, for example, the flow rate of the raw material supplied into the barrier section 82 via the screw flight 84 of the conveying section 81 is reduced to a certain degree, the reduced amount can be compensated by the raw material collected in the material container R. Thereby, the raw material can be reliably supplied to the passage 86.

[0159] As indicated by the dashed arrows in Fig. 22, the raw material that has passed through the second passage element 88 of the passage 86 is returned by the third passage element 89 to the outer peripheral surfaces of the cylindrical members 39 of the adjacent conveying sections 81. The returned raw material is conveyed toward the distal end of the screw body 37 via the screw flights 84 of the adjacent conveying sections 81 and again receives a shearing effect during this conveying. The raw material that has received the gravitational effect flows into the second passage element 88 through the first passage element 87 of a subsequent passage 86 and again receives an elongation effect during passage through the second passage element 88.

[0160] In the axially central portion of the screw body 37, a plurality of conveying sections 81 and a plurality of barrier sections 82 are alternately arranged, and a plurality of passages 86 are arranged at intervals along the axis of the screw body 37. This structure enables the raw material fed through the feed port 34 into the screw body 37 to be continuously conveyed from the proximal end side of the screw body 37 to the distal end side thereof with alternately repeated shearing and elongation actions. As a result, the kneading degree of the raw material is improved and the dispersion of the macromolecular component of the raw material is promoted.

[0161] The second passage elements 88 of the passages 86 are open to the outer peripheral surface of the screw body 37 through the respective first and third passage elements 87 and 89. Accordingly, in each passage 86, the raw material flowing into the second passage element 88 through the first passage element 87 always returns to the outer peripheral surface of the screw body 37 through the third passage element 89. That is, the mixed raw material does not appear at the passages 86.

[0162] Due to the above structure, the raw material is prevented from being kneaded excessively, thus ensuring appropriate kneading for a desired degree of kneading.

[0163] In the third embodiment, the passage 86 for applying an elongation effect to the raw material extends along the axis of the screw body 37 in an eccentric position with respect to the axis O1 as the rotation axis of the screw body 37. To this end, the passage 86 revolves around the axis O1. In other words, the cylindrical wall surface 92 defining the passage 86 revolves around the axis O1 instead of rotating around the axis O1.

[0164] Due to this, the raw material is prevented from being excessively agitated in the passage 86 when passing through the passage 86. Furthermore, the raw material passing through the passage 86 hardly receives a shearing action and is mainly subjected to an elongation action after returning to the outer peripheral surface of the conveying section 81 through the passage 86.

[0165] That is, also in the screw 21 of the third embodiment, the respective portions in which the shearing action and the elongation action are exerted on the raw material can be precisely determined, thereby achieving the same advantages as in the first embodiment. [Modification of the third embodiment]

[0166] Fig. Figure 23 shows a modification of the third embodiment. This modification differs from the third embodiment in the structure of the barrier section 82 of the screw body 37. As shown in Fig. 23, the barrier portion 82 includes a wide-diameter cylindrical portion 95 extending along the axis of the screw body 37. The wide-diameter portion 95 has a continuous outer peripheral surface 95a along the circumference of the screw body 37 and is the same length as the barrier portion 82 along the axis of the screw body 37. It is desirable that the outer peripheral surface 95a of the wide-diameter portion 95 have a smooth surface free of indentations and / or cutouts. [Fourth Embodiment]

[0167] Fig. Figures 24 to 31 show a fourth embodiment. The fourth embodiment differs from the first embodiment with respect to the screw body 37 of the screw 21. The other structures of the second extruder 3 are similar to those of the first embodiment. For this reason, the same elements as in the first embodiment are provided with the corresponding reference numerals and will not be described in detail.

[0168] As in Fig. 24 to 26, a plurality of cylindrical members 39 forming the screw body 37 are secured between the first collar 48 and the second collar 50 along the axis of the second shaft portion 41, with the end surfaces 39a of the adjacent cylindrical members 39 being joined together without a gap.

[0169] The screw body 37 has a plurality of conveying sections 101 for conveying the raw materials, a plurality of barrier sections 102 for restricting the flow of the raw materials, and a plurality of circulating sections 103 for temporarily circulating the raw materials. The conveying sections 101, the barrier sections 102, and the circulating sections 103 are arranged along the axis of the screw body 37.

[0170] The conveying sections 101 have respective screw flights 105. The screw flights 105 project into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 105 form the outer peripheral surfaces of the conveying sections 101. The screw flights 105 are spiraled to cooperate to convey the raw materials from the proximal end of the screw body 37 to the distal end thereof when the screw 21 rotates counterclockwise. In other words, the screw flights 105 are spiraled clockwise, like a right-handed screw.

[0171] In the embodiment, a plurality of conveying sections 101 are continuously arranged at both ends, the proximal end and the distal end, of the screw body 37. The feed port 34 of the housing 20 is located opposite the axially central portion of one of the conveying sections 101 at the proximal end of the screw body 37.

[0172] The length of the conveying section 101 along the axis of the screw body 37 is approximately determined in accordance with, for example, the types and / or kneading degrees of raw materials and / or the amount of kneaded product per unit time. Furthermore, although the conveying sections 101 are regions where the screw flights 105 are formed at least on the outer peripheral surfaces of the cylindrical members 39, they are not limited to the regions between the starting and ending points of the screw flights 105.

[0173] In other words, a portion of the outer peripheral surface of the cylindrical member 39 that deviates from the screw thread 105 may also be considered the conveying section 101. Furthermore, if a cylindrical spacer or collar exists adjacent to the cylindrical member 39 with the screw thread 105, it may also be included in the conveying section 101.

[0174] The barrier sections 102 are arranged at intervals along the axis of the screw body 37 in the central portion thereof, located between its proximal and distal ends. The barrier sections 102 have respective screw flights 107. The screw flights 107 project into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 107 form the outer peripheral surfaces of the barrier sections 102. The screw flights 107 are spiraled to cooperate to convey raw materials from the distal end of the screw body 37 to the proximal end thereof when the screw 21 rotates counterclockwise. In other words, the screw flights 107 are spiraled counterclockwise, like a left-handed screw. The pitch of the screw flight 107 of each barrier section 102 is the same as or less than that of the screw flight 105 of each conveyor section 101.

[0175] In addition, the entire length of the barrier section 102 along the axis of the screw body 37 is shorter than that of the conveying section 101. In addition, the gap between the upper portion of the screw flight 107 and the inner peripheral surface of the cylindrical portion 33 of the housing 20 is slightly smaller than that between the upper portion of the screw flight 105 and the inner peripheral surfaces of the cylindrical portion 33 of the housing 20.

[0176] The length of the barrier section 102 along the axis of the screw body 37 is approximately determined in accordance with, for example, the types and / or kneading degrees of raw materials and / or the amount of kneaded product per unit time. The barrier section 102 serves to block the flow of raw materials conveyed by the conveying section 101. That is, the barrier section 102 is designed to prevent the raw materials conveyed via the conveying section 101 from passing through the gap between the upper portion of the screw flight 107 and the inner peripheral surface of the cylindrical section 33.

[0177] Each circulation section 103 is adjacent to a corresponding barrier section 102 at a position close to the proximal end of the rotary shaft 38 and includes first, second, and third flights 110, 111, and 112. In the embodiment, the first, second, and third flights 110, 111, and 112 are arranged in this order in a direction from the barrier section 102 to the proximal end of the screw body 37.

[0178] The first, second and third screw flights 110, 111 and 112 project into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39, and the upper portions of the screw flights 110, 111 and 112 form the outer peripheral surfaces of the circulation section 103.

[0179] The first, second, and third flights 110, 111, and 112 are arranged continuously along the axis of the screw body 37 and are twisted to cooperate to convey raw materials from the proximal end of the screw body 37 to the distal end thereof when the screw 21 rotates counterclockwise. In other words, the first, second, and third flights 110, 111, and 112 are twisted clockwise, like a right-handed screw.

[0180] The pitch of the first screw flight 110 is the same as or greater than that of the screw flight 107 of the adjacent barrier section 102. The pitch of the second screw flight 111 is smaller than that of the first screw flight 110. The pitch of the third screw flight 112 is greater than that of the second screw flight 111. A slight clearance is ensured between the upper portions of the first, second, and third screw flights 110, 111, and 112 and the inner peripheral surfaces of the cylindrical portion 33 of the housing 20.

[0181] In the screw 21 of the embodiment, various types of screw flights 105, 107, 110, 111, and 112 all project into the conveying passage 51 from the outer peripheral surfaces of the cylindrical members 39 with the same outer diameter D1. Thus, the outer peripheral surfaces of the cylindrical members 39 define the core diameter of the screw 21. The core diameter of the screw 21 is kept constant over the entire length of the screw 21.

[0182] As in Fig. As shown in Figures 24 to 26, the screw body 37 has a plurality of passages 115 extending along the axis of the screw body 37. The passages 115 are formed within the cylindrical members 39 at respective positions corresponding to the first screw flights 110 and are arranged at intervals along the axis of the screw body 37.

[0183] The passages 115 extend parallel to the axis O1 of the screw body 37. In other words, the passages 115 extend along the axis of the cylindrical members 39 without branching and have a predetermined length.

[0184] Since the passages 115 are provided in the cylindrical members 39, they extend eccentrically with respect to the axis O1 of the screw body 37. As a result, the passages 115 revolve around the axis O1 when the screw body 37 rotates.

[0185] As in Fig. 27, the passages 115 are defined, for example, as a bore with a circular cross-section. The inner diameter of the bore forming the passage 115 is set, for example, to 1 mm or more and less than 6 mm, and preferably to 1 mm or more and 5 mm or less. Furthermore, the cross-section of the passage 115 is selected to be substantially smaller than the cross-section of the discharge passage 51, which extends radially with respect to the cylindrical portion 33.

[0186] Furthermore, the cylindrical member 39, in which the first screw flight 110 is formed, has a cylindrical wall surface 116 defining the bore. The passage 115, surrounded by the wall surface 116, is a cavity that only allows raw materials to pass through and does not contain any element forming the screw body 37. Also, the wall surface 116 revolves around the axis O1 instead of rotating around the axis O1 when the screw body 37 rotates around the axis O1.

[0187] As in Fig. 26 and Fig. 31, the passage 115 has an inlet 117 and an outlet 118. The inlet 117 is located in front of the barrier portion 102, which is adjacent to the circulating portion 103, at a position close to the distal end of the rotary shaft 38. In the embodiment, a slit 120, open to the outer peripheral surface of the cylindrical member 39, is formed in one end surface of the cylindrical member 39 constituting the circulating portion 103, and the inlet 117 is formed in the inner surface of the slit 120.

[0188] The outlet 118 is located at the boundary of the first and second screw flights 110 and 111. In the embodiment, a slot 121 open to the outer peripheral surface of the cylindrical member 39 is formed in the end surface of the cylindrical member 39, which forms the circulation section 103, and the outlet 118 is formed in the inner surface of the slot 121. Thus, the inlet 117 and the outlet 118 are separated from each other along the axis of the screw body 37 at a position corresponding to the first screw flight 110.

[0189] In the embodiment, it is desirable to leave the open area of ​​the inlet 117 open to the inner surface of the slot 120 and to leave the open area of ​​the outlet 118 open to the inner surface of the slot 121 by an amount equal to or greater than the cross-section of the passage 115.

[0190] Furthermore, if a plurality of cylindrical members 39 are removed from the rotating shaft 38 to thereby disassemble the screw 21, each cylindrical member 39 including the first screw flight 110 and the passage 115 can be considered a screw element. Similarly, if a plurality of cylindrical members 39 provided with further screw flights 105, 107, 111, and 112 are removed from the rotating shaft 38, each cylindrical member 39 removed from the rotating shaft 38 can be considered a screw element.

[0191] In the above structure, the flowable raw material mixed via the first extruder 2 is continuously conveyed to the conveying passage 51 through the feed port 34 of the second extruder 3. The raw material supplied to the second extruder 3 is conveyed to the outer peripheral surface of one of the conveying sections 101 arranged at the proximal end of the screw body 37, as indicated by arrow D in FIG. Fig. 30 is specified.

[0192] Since the screw 21 is rotated counterclockwise - viewed from the proximal end of the rotary shaft 38 - the screw flight 105 of the conveying section 101 conveys the raw material introduced via the feed port 34 to the adjacent circulating section 103. The first, second and third screw flights 110, 111 and 112 of the circulating section 103 continuously convey the raw material towards the distal end of the screw body 37, as indicated by the solid arrows in Fig. 30 and Fig. 31 is specified.

[0193] At this time, a shearing action caused by the difference in speed between the screw flights 105, 110, 111, and 112 rotating in the conveying passage 51 and the inner peripheral surface of the cylindrical portion 33 is exerted on the raw material, and the raw material is thus stirred by the slight rotation of the screw flights 105, 110, 111, and 112. As a result, the raw material is thoroughly kneaded, and a favorable dispersion of the macromolecular component of the raw material occurs.

[0194] The sheared raw material is conveyed along the conveying passage 51 and reaches the boundary of the barrier section 102 and the circulating section 103. The flight 107 of the barrier section 102 conveys the raw material from the distal end side of the screw body 37 to the proximal end side thereof when the screw 21 is rotated counterclockwise, thereby locking the raw material supplied via the first flight 110.

[0195] That is, when the screw 21 is rotated counterclockwise, the flight 107 of the barrier portion 102 limits the flow of the raw material supplied via the first flight 110 of the circulating portion 103 and prevents the raw material from passing through a gap between the outer peripheral surface of the barrier portion 102 and the inner peripheral surface of the cylindrical portion 33.

[0196] As a result, the pressure of the raw material increases at the boundary between the circulation section 103 and the barrier section 102. In particular, Fig. 31, the fill levels of the raw material are indicated in gradations in positions in the conveyor passage 51 corresponding to the conveyor sections 115. This means that the deeper the gradation, the higher the fill level. As can be seen from Fig. As can be seen from Figure 31, in the conveying passage 51, the closer the second screw flight 111 of the circulation section 103 is to the barrier section 102, the higher the raw material filling level. Furthermore, in a position closest to the barrier section 102, the raw material filling level is 100%.

[0197] As a result, a material container R with a filling degree of 100% is formed in the position closest to the barrier section 102. In the material container R, the pressure of the raw material is increased because it is blocked by the barrier section 102. The increased-pressure raw material is introduced through the slot 120 into the inlet 117 located in front of the barrier section 102 and flows into the passage 115 through the inlet 117, as indicated by the dashed arrows in Fig. 30 and Fig. 31. The raw material that has flowed into passage 115 circulates from the distal end side of the screw body 37 to the proximal end side thereof. The direction of the raw material flow in passage 115 is opposite to that of the material supplied via the screw flights 105, 110, 111, and 112.

[0198] The cross-section of passage 115 is smaller than the cross-section of the conveying passage 51, which extends radially with respect to the cylindrical portion 33. In other words, because the inner diameter of passage 115 is substantially smaller than the outer diameter of the screw body 37, the raw material is drastically restricted as it passes through passage 115, exerting an elongation effect on the raw material.

[0199] Since the cross section of the passage 115 is sufficiently smaller than that of the conveying passage 51, the material container R in front of the barrier section 102 does not shrink even though the raw material collected in the material container R flows into the passage 115. Accordingly, even if, for example, the flow rate of the raw material supplied into the barrier section 102 via the first screw flight 110 is reduced to a certain extent, the reduced amount can be compensated by the raw material accumulated in the material container R. This allows the raw material to be reliably supplied to the passage 115.

[0200] The raw material that has passed through the passage 115 is returned through the outlet 118 and the slot 121 to the outer peripheral surface of the cylindrical member 39, which forms the circulation section 103. The returned raw material is conveyed toward the distal end of the screw bodies 37 via the first screw flight 110 and is subjected to a shearing action during this conveying.

[0201] In the embodiment, a portion of the raw material conveyed to the barrier section 102 via the first flight 110 is again fed through the inlet 117 to the passage 115, and the circulation of the material is temporarily repeated in the circulation section 103. The remaining raw material conveyed to the barrier section 102 passes through the gap between the upper portion of the flight 107 of the barrier section 102 and the inner peripheral surface of the cylindrical section 33. This raw material is guided to the distal end of the screw body 37 via the first, second, and third flights 110, 111, and 112 of the adjacent circulation section 103.

[0202] The passages 115 open to the outer peripheral surfaces of the respective cylindrical members 39 through the respective inlet 117 and outlet 118.

[0203] Accordingly, the raw material that has flowed through the corresponding inlet 117 is always returned to each passage 115 to the outer peripheral surface of the cylindrical member 39 of the corresponding circulation section 103 through the corresponding outlet 118. That is, the mixed raw material does not appear at the passages 115.

[0204] This avoids excessive kneading of raw materials, resulting in proper kneading to ensure a desired degree of kneading.

[0205] In the screw 21 of the embodiment, a plurality of barrier sections 102 and a plurality of circulating sections 103 are alternately arranged along the axis of the screw body 37. Furthermore, a plurality of passages 115 are arranged at intervals along the axis of the screw body 37 at positions corresponding to the first flights 110 of the plurality of circulating sections 103. Due to this structure, the raw material supplied to the screw body 37 through the feed port 34 is continuously conveyed from the proximal end of the screw body 37 to the distal end thereof while being alternately subjected to shearing action and elongation action. As a result, the kneading degree of the raw material is increased, thus promoting the dispersion of the macromolecular component of the raw material.

[0206] In the fourth embodiment, the passage 115 for applying the elongation effect to the raw material extends along the axis of the screw body 37 in an eccentric position with respect to the rotation axis O1 of the screw body 37, thereby orbiting around the axis O1. In other words, the cylindrical wall surface 116 defining the passage 115 orbits around the axis O1 instead of rotating around the axis O1.

[0207] As a result, when the raw material passes through passage 115, it is free from shear forces due to the rotation of wall surface 116 around its own axis, although it experiences centrifugal force. The raw material passing through passage 115 and returning to the outer peripheral surface of the cylindrical member 39 of the circulation section 103 therefore primarily experiences the elongation effect.

[0208] For this purpose, in the fourth embodiment, the respective sections of the screw 21 in which the shearing action and the elongation action are applied to the raw material can be precisely determined, thereby achieving the same advantage as in the first embodiment. [Modification 1 of the fourth embodiment]

[0209] Fig. 32 shows a modification 1 of the fourth embodiment.

[0210] Modification 1 differs from the fourth embodiment with respect to the passage 115 for applying an elongation effect to the raw materials. The other structures are substantially similar to those of the fourth embodiment.

[0211] As in Fig. As shown in Figure 32, the first flight 110 of the circulation section 103 is formed on the rotating shaft 38, thereby covering two adjacent cylindrical members 39. The two cylindrical members 39 with the first flight 110 provided thereon have the same length L along the axis of the rotating shaft 38.

[0212] In addition, the passage 115 for applying the elongation effect to the raw materials is continuously formed in the two cylindrical members 39 having the first screw thread 110 formed thereon. Specifically, the passage 115 is formed by the first, second, and third passage elements 131, 132, and 133.

[0213] The first passage element 131 can be considered the inlet of the passage 115. The first passage element 131 opens onto the outer peripheral surface of one of the two adjacent cylindrical members 39 near the barrier section 102. The open end of the first passage element 131 diverges from the first screw flight 110 and is located in front of the adjacent barrier section 102.

[0214] Furthermore, the first through-passage element 131 is formed by performing a machining process on the outer peripheral surface of one of the cylindrical members 39 using, for example, a drill. To this end, the first through-passage element 131 is a bore with a circular cross-section and extends radially into the one cylindrical member 39 from the outer peripheral surface thereof, intersecting the axis O1. The lower portion 131a of the first through-passage element 131 forms a slope resulting from the conical shape of the one cylindrical member 39 being cut by the tip of the drill.

[0215] The second passage element 132 can be considered as the main passage section in which raw materials circulate. As shown in Fig. 32, the second passage element 132 extends in the two adjacent cylindrical members 39 parallel to the axis O1 of the screw body 37. For this purpose, the second passage element 132 extends along the axis of the screw body 37 without branching and has a predetermined length.

[0216] The second passage element 132 has a first portion 134a formed in one cylindrical member 39 and a second portion 134b formed in the other cylindrical member 39. The first portion 134a of the second passage element 132 extends along the axis of one cylindrical member 39 and opens to the end surface 39a of one cylindrical member 39 near the other cylindrical member 39. The end of the first portion 134a opposite its open end is closed by the end wall 39b of the one cylindrical member 39.

[0217] In this modification, the first portion 134a of the second through member 132 is formed by performing a machining process on the one cylindrical member 39 from the end surface 39a thereof using, for example, a drill. Therefore, the first portion 134a is defined as a bore with a circular cross-section.

[0218] The second portion 134b of the second passage member 132 extends along the axis of the other cylindrical member 39 and opens to the end surface 39a of the other cylindrical member 39 close to the one cylindrical member 39. The end of the second portion 134b opposite the open end thereof is closed by the end wall 39b of the other cylindrical member 39.

[0219] In this modification, the second portion 134b of the second through member 132 is formed by performing a machining process on the other cylindrical member 39 from the end surface 39a thereof using, for example, a drill. To this end, the second portion 134b is defined as a bore with a circular cross-section, like the first portion 134a.

[0220] In addition, the open end of the first portion 134a and the open end of the second portion 134b are formed to abut coaxially with each other so that they communicate with each other when the two adjacent cylindrical members 39 are fixed along the axis of the rotary shaft 38.

[0221] The third passage element 133 can be considered the outlet of the passage 115. The third passage element 133 opens onto the outer peripheral surface of the other cylindrical member 39 contained within the two adjacent cylindrical members 39. The open end of the third passage element 133 diverges from the first screw flight 110 and is located in front of the second screw flight 111 of the circulation section 103. For this purpose, the first and third passage elements 131 and 133 are separated from each other along the axis of the screw body 37.

[0222] In the modification, the third through-passage element 133 is formed by performing a machining process on the outer peripheral surface of the other cylindrical members 39 using, for example, a drill. To this end, the third through-passage element 133 is a bore with a circular cross-section and extends radially into the other cylindrical member 39 from the outer peripheral surface thereof. The lower portion 133a of the third through-passage element 133 forms a slope resulting from capping the other cylindrical member 39 in the shape of a cone with the tip of the drill.

[0223] As in Fig. As shown in Fig. 32, the end of the first portion 134a of the second passage member 132, which is opposite to the open end thereof, is connected to the first passage member 131 in the one cylindrical member 39. The first passage member 131 and the first portion 134a of the second passage member 132 communicate with each other while maintaining their circular cross sections. Furthermore, the first portion 134a of the second passage member 132 is connected to the first passage member 131 at a position different from the conical lower portion 131a of the first passage member 131.

[0224] Accordingly, the first passage member 131 can be considered as a first upright portion which is radially erected with respect to the cylindrical member 39 from the end of the first portion 134a of the second passage member 132 so as to open toward the outer peripheral surface of the screw body 37.

[0225] The end of the second portion 134b of the second passage member 132, opposite its open end, is connected to the third passage member 133 in the other cylindrical member 39. The third passage member 133 and the second portion 134b of the second passage member 132 communicate with each other, maintaining their circular cross-sections. Furthermore, the second portion 134b of the second passage member 132 is connected to the third passage member 133 at a position different from the conical lower portion 133a of the third passage member 133.

[0226] Accordingly, the third passage member 133 can be considered as a second upright portion erected radially with respect to the cylindrical member 39 from the end of the second portion 134b of the second passage member 132 so as to open toward the outer peripheral surface of the screw body 37.

[0227] It is recommended to set the inner diameter of the bore constituting the second passage member 132, for example, to not less than 1 mm and less than 6 mm, and preferably to a range of 1 mm or more to 5 mm or less. The inner diameter of the second passage member 132 is smaller than that of the first passage member 131 as the inlet. The cross section of the second passage member 132 is set substantially smaller than the cross section of the discharge passage 51 extending radially with respect to the cylindrical portion 33.

[0228] In addition, the cylindrical members 39 have a cylindrical wall surface that defines the bores forming the first, second, and third passage elements 131, 132, and 133. The first, second, and third passage elements 131, 132, and 133, defined by the wall surfaces 135, are cavities that allow only raw materials to pass through and do not contain any element forming the screw body 37. Also, the wall surface 135 revolves around the axis O1 instead of rotating around the axis O1 when the screw body 37 rotates around the axis O1.

[0229] Thus, when raw materials pass through the above-mentioned passage 115, they are free from shearing force, although they experience centrifugal force. Therefore, Modification 1 can achieve the same advantage as the fourth embodiment.

[0230] It is not always necessary to form the second passage element 132 of the passage 115 parallel to the axis O1 of the screw body 37. For example, the second passage element 132 may be inclined with respect to the axis O1, as shown by the dot-dash line in Fig. 32, so that the end of the second passage element 132 away from the first passage element 131 opens directly to the outer peripheral surface of the cylindrical member 39.

[0231] With this structure, the third passage member 133 as an outlet of the raw materials can be omitted, thereby simplifying the shape of the passage 115. [Modification 2 of the fourth embodiment]

[0232] Fig. 33 shows modification 2 of the fourth embodiment.

[0233] In the Fig. In modification 2 shown in FIG. 33, two cylindrical members 39, on which the first screw thread 110 is formed, have different lengths. Specifically, one of the cylindrical members 39, which includes the first portion 134a of the second passage element 132, has a length L1 longer than the length L2 of the other cylindrical member 39, which includes the second portion 134b of the second passage element 132.

[0234] In Variation 2, when two additional cylindrical members 39 have a length L3 along the axis of the rotary shaft 38, in addition to the two cylindrical members 39 described above, the first screw thread 110 is provided, and the lengths of the two cylindrical members 39 with the first screw thread 110 can be adjusted in three stages. Specifically, the combination of the cylindrical members with lengths L1 and L2, the combination of the cylindrical members with lengths L1 and L3, and the combination of the cylindrical members with lengths L2 and L3 are possible. This means that the entire length of the passage 115 can be easily varied. [Modification 3 of the fourth embodiment]

[0235] Fig. 34 to 36 show the modification 3 in connection with the modification 1 of the fourth embodiment.

[0236] As in Fig. 34 and Fig. As shown in Fig. 35, the end of the first portion 134a of the second passage member 132, which is opposite to the open end thereof, is connected to the conical lower portion 131a of the first passage member 131 so as to perpendicularly cross the first passage member 131. The lower portion 131a of the first passage member 131 has a circular opening 140a communicating with the second passage member 132. The opening 140a faces the further portion of the lower portion 131a, which is inclined toward the outer peripheral surface of the screw body 37.

[0237] The end of the second portion 134b of the second passage member 132, opposite the open end thereof, is connected to the conical lower portion 133a of the third passage member 133 so as to perpendicularly intersect the third passage member 133. The lower portion 133a of the third passage member 133 has a circular opening 140b communicating with the second passage member 132. The opening 140b faces the other portion of the lower portion 133a, which is inclined toward the outer peripheral surface of the screw body 37.

[0238] In the modification 3, the raw material which has flowed into the first passage member 131 and reached the lower portion 131a of the first passage member 131 is guided to the opening 140a along the slope of the lower portion 131a as indicated by the arrow in Fig. 35(A). As a result, the raw material flows smoothly to the second passage member 132 without stagnation at the lower portion 131a of the first passage member 131.

[0239] The raw material passing through the second passage member 132 flows to the lower portion 133a of the third passage member 133 through the opening 140b. The raw material reaching the third passage member 133 is guided to the outer peripheral surface of the screw body 37 along the slope of the lower portion 133a, as indicated by the arrow in Fig. 36(A). This causes the raw material to be smoothly returned to the outer peripheral surface of the screw body 37 without stagnation at the lower portion 133a of the third passage member 133.

[0240] As described above, the partial stagnation of the raw material in the passage 115 can be avoided, whereby a desired elongation effect can be exerted on the raw material passing through the passage 115.

[0241] In the modification 3, the lower portion 131a of the first passage member 131 and the lower portion 133a of the third passage member 133 are not limited to the conical shape, but may be of, for example, a hemispherical shape. [Modification 4 of the fourth embodiment]

[0242] Fig. 37 shows a modification 4 in connection with the modification 1 of the fourth embodiment.

[0243] Modification 4 differs from Modification 1 in the structure of the second portion 134b of the second passage member 132. As shown in Fig. As shown in Fig. 37, the second portion 134b has a straight portion 134c and a tapered portion 134d. The straight portion 134c and the tapered portion 134d are formed by cutting the cylindrical member 39 from the end surface 39a side of the cylindrical member 39.

[0244] The straight section 134c is connected to the third passage element 133. The inner diameter of the straight section 134c is smaller than that of the first section 134a of the second passage element 132. The tapered section 134d is open toward the end surface 39a of the further cylindrical member 39 and is coaxially connected to the straight section 134c. The inner diameter of the tapered section 134d gradually decreases from the end surface 39a of the further cylindrical member 39 to the straight section 134c. This means that the inner diameter of the second passage element 132, as the main element for applying an elongation effect to the raw material, varies in its central section with respect to the raw material flow.

[0245] The tapered portion 134d is formed, for example, by forming a pre-machined hole in the end surface 39a of the further cylindrical member 39 and then reaming the inner peripheral surface of the pre-machined hole using a reamer. The pre-machined hole also serves as the straight portion 134c.

[0246] In Modification 4, the second portion 134b of the second passage member 132 has the tapered portion 134d located upstream of the straight portion 134c at the central portion of the second passage member 132. As a result, the second passage member 132 has its central portion gradually reduced in inner diameter, thereby increasing the elongation effect exerted on the raw material when the raw material passes through the second passage member 132. [Modification 5 of the fourth embodiment]

[0247] Fig. 38 shows a modification 5 of the fourth embodiment.

[0248] In the Fig. In modification 5 shown in FIG. 38, the passage 115 is formed in one of the cylindrical members 39. The second passage element 132 of the passage 115 is formed, for example, by performing a machining process on the one cylindrical member 39 from the end surface 39a side thereof, for example, using a drill.

[0249] As a result, a through-hole 150 with a circular cross-section is formed through the cylindrical member 39 along its axis so as to open toward the opposite end surfaces 39a of the cylindrical member 39. The through-hole 150 intersects the first and third through-hole elements 131 and 133 in the cylindrical member 39.

[0250] The opposite, open ends of the through-hole 150 are individually sealed in a fluid-tight manner by caps 151a and 151b. This structure defines the second passage element 132 in a cylindrical member 39, which connects the first and third passage elements 131 and 133.

[0251] When the through-hole 150 is formed in the cylindrical member 39, the distal end of the through-hole 150 may be closed by the end wall 39b of the cylindrical member 39, instead of the distal end communicating with the end surface 39a of the cylindrical member 39. [Modification 6 of the fourth embodiment]

[0252] Fig. 39 shows a modification 6, which is achieved by a further development of modification 5.

[0253] As in Fig. 39, the through-hole 150 extending through a cylindrical member 39 includes an upstream portion 150a, a downstream portion 150b, and a central portion 150c. The upstream portion 150a, the downstream portion 150b, and the central portion 150c are arranged coaxially along the axis of the cylindrical member 39. The upstream portion 150a intersects the first passage member 131 in the cylindrical member 39 and opens toward an end surface 39a of the cylindrical member 39. The open end of the upstream portion 150a is fluid-tightly closed by a cap 151a.

[0254] The inner diameter of the downstream portion 150b is smaller than that of the upstream portion 150a. The downstream portion 150b intersects the third passage member 133 in the cylindrical member 39 and opens to the other end surface 39a of the cylindrical member 39. The open end of the downstream portion 150b is sealed in a liquid-tight manner by a cap 151b.

[0255] The central portion 150c is disposed between the upstream portion 150a and the downstream portion 150b.

[0256] The inner diameter of the central portion 150c is gradually reduced from the upstream portion 150a side to the downstream portion 150b side. Accordingly, the inner diameter of the second passage member 132, as the main member for applying an elongation effect to the raw material, is varied at an intermediate position with respect to the flow direction of the raw material.

[0257] As described above, in the second passage member 132 of the passage 115 according to Modification 6, the inner diameter of the central portion 150c is gradually reduced from the upstream side to the downstream side. Therefore, the elongation effect applied to the raw material is increased when the raw material passes through the second passage member 132. [Fifth Embodiment]

[0258] Fig. Figure 40 shows a fifth embodiment. The fifth embodiment differs from the first embodiment in the structure for applying an elongation effect to raw materials. The other structures of the screw 21 are similar to those of the first embodiment.

[0259] As in Fig. As shown in Fig. 40, a pair of slots 161a and 161b are formed in the inner peripheral surface of the cylindrical member 39. The slots 161a and 161b extend along the axis of the screw body 37 and are diametrically separated from each other with respect to the screw body 37. Furthermore, the slots 161a and 161b are open toward the inner peripheral surface of the cylindrical member 39.

[0260] The open ends of the slots 161a and 161b are closed by the outer peripheral surface of the second shaft portion 41 of the rotary shaft 38 when the cylindrical member 39 is attached to the second shaft portion 41. Thus, the slots 161a and 161b cooperate with the outer peripheral surface of the second shaft portion 41 to define the passages 162 for applying an elongation effect to raw materials. In the embodiment, the passages 162 are arranged at the boundary regions of the rotary shaft 38 and the cylindrical member 39.

[0261] In the fifth embodiment, the passages 162 in the screw body 37 are arranged in positions eccentric with respect to the axis O1 of the rotating shaft 38. Therefore, the passages 162 revolve around the axis O1 when the screw body 37 rotates, as in the first embodiment.

[0262] In the fifth embodiment, when the cylindrical member 39 is attached to the second shaft portion 41 of the rotary shaft 38, the passages 162 are formed in the screw body 37. Since the slits 161a and 161b defining the passages 162 are open to the inner peripheral surface of the cylindrical member 39, they can be easily formed.

[0263] If it is necessary, for example, to change the cross-sectional shape of each passage 162, this can be done easily. [Sixth Embodiment]

[0264] Fig. Figure 41 shows a sixth embodiment. The sixth embodiment differs from the fifth embodiment in the structure for applying an elongation effect to raw materials. The other structures of the screw 21 are similar to those of the fifth embodiment.

[0265] As in Fig. 41, a pair of slots 171a and 171b are formed in the outer peripheral surface of the second shaft portion 41 of the rotary shaft 38. The slots 171a and 171b extend along the axis of the second shaft portion 41 and are diametrically separated from each other. Furthermore, the slots 171a and 171b are open toward the outer peripheral surface of the second shaft portion 41.

[0266] The open ends of the slots 171a and 171b are closed by the inner peripheral surface of the cylindrical member 39 when the cylindrical member 39 is attached to the second shaft portion 41 of the rotary shaft 38. Thus, the slots 171a and 171b cooperate with the inner peripheral surface of the cylindrical member 39 to define passages 172 for applying an elongation effect to raw materials. In the embodiment, the passages 172 are formed at the boundary regions of the rotary shaft 38 and the cylindrical member 39.

[0267] In the sixth embodiment, the passages 172 in the screw body 37 are arranged in positions eccentric with respect to the axis O1 of the rotating shaft 38. Therefore, the passages 172 revolve around the axis O1 when the screw body 37 rotates, as in the fifth embodiment.

[0268] In the sixth embodiment, when the cylindrical member 39 is attached to the second shaft portion 41 of the rotating shaft 38, the passages 172 are formed in the worm body 37. Since the slots 171a and 171b defining the passages 172 are open to the outer peripheral surface of the rotating shaft 38, they can be easily formed.

[0269] If it is necessary, for example, to change the cross-sectional shape of each passage 172, this can be done easily. [Seventh Embodiment]

[0270] Fig. Figure 42 shows a seventh embodiment. The seventh embodiment differs from the first embodiment in the structure for applying an elongation effect to raw materials. The other structures of the screw 21 are similar to those of the first embodiment.

[0271] As in Fig. 42, notches 181a and 181b are formed in the distal end surfaces of keys 45a and 45b projecting from the outer peripheral surface of the second shaft portion 41. The notches 181a and 181b are formed along the axis of the second shaft portion 41 and are open toward the distal end surfaces of the keys 45a and 45b. The open ends of the notches 181a and 181b are closed by the inner peripheral surfaces of the keyways 47a and 47b formed in the cylindrical member 39 when the keys 45a and 45b are respectively engaged with the keyways 47a and 47b. As a result, the notches 181a and 181b interact with the inner peripheral surfaces of the keyways 47a and 47b to define passages 182 for applying an elongation effect to the raw materials. In the embodiment, the passages 182 are formed at the boundary regions of the keys 45a and 45b and the cylindrical member 39.

[0272] In the seventh embodiment, the passages 182 in the screw body 37 are arranged in positions eccentric with respect to the axis O1 of the rotating shaft 38. Therefore, the passages 182 revolve around the axis O1 when the screw body 37 rotates, as in the fifth embodiment.

[0273] In the seventh embodiment, when the keys 45a and 45b of the rotary shaft 38 are engaged with the keyways 47a and 47b of the cylindrical member 39, the passages 182 are formed in the worm body 37. Since the notches 181a and 181b defining the passages 182 are open toward the distal end surfaces of the keys 45a and 45b, they can be easily formed.

[0274] If it is necessary, for example, to change the cross-sectional shape of each passage 182, this can be done easily.

[0275] The seventh embodiment may be modified such that further cuts extending along the axis of the second shaft portion 41 are formed in the inner peripheral surfaces of the keyways 47a and 47b and coupled with the cuts 181a and 181b to thereby define the passages 182. [Eighth Embodiment]

[0276] Fig. Fig. 43 shows an eighth embodiment. The eighth embodiment differs from the first embodiment in the structure of the screw 21 and the structure for applying an elongation effect to raw materials.

[0277] As in Fig. As shown in Figure 43, the screw 21 includes a fixed screw body 200. The screw body 200 includes a rectilinear axial portion 201. The axial portion 201 has an axis O1 extending through its central portion and is concentrically contained within the cylindrical portion 33 of the housing 20.

[0278] The axial part 201 has an outer peripheral surface 201a that faces the inner peripheral surface of the cylindrical portion 33 of the housing 20. The screw flight 202 for conveying the raw materials is formed on the outer peripheral surface 201a of the axial part 201.

[0279] Furthermore, a pair of passages 203 for applying an elongation effect to the raw materials are formed in the axial part 201. The passages 203 extend parallel to each other along the axis of the axial part 201, with an axis O1 interposed therebetween. Thus, the passages 203 are arranged in the screw body 200 at positions eccentric with respect to the axis O1 of the axial part 201. As a result, the passages 203 revolve around the axis O1 when the screw body 200 rotates, as in the first embodiment.

[0280] The passages 203 for applying the elongation effect to raw materials may be formed in the screw body 200 even if the screw body 200 is formed from the axial part 201. Therefore, the screw body is not limited to a structure combining a rotary shaft and cylindrical members.

[0281] The embodiments described above are presented only as examples and are not intended to limit the scope of the invention. The embodiments may be modified in various ways without departing from the scope of the invention. For example, various omissions, substitutions, changes, etc. may be made.

[0282] For example, the passage used to apply an elongation effect to raw materials is not limited to a hole with a circular cross-section. It can be a hole with, for example, an elliptical or polygonal cross-section.

[0283] Furthermore, the first embodiment focuses on an exemplary case where the worm 21 is rotated counterclockwise when the worm body 37 is viewed from the proximal end of the rotating shaft 38. However, the invention is not limited to this. For example, the worm 21 may be rotated clockwise.

[0284] In this case, the screw flight 56 ​​provided at the conveying section 54 of the screw 21 may be wound clockwise, like a right-handed screw, so that the raw materials are conveyed from the distal end side of the screw body 37 to the proximal end side. Similarly, the screw flight 57 provided at the barrier section 55 may be wound counterclockwise, like a left-handed screw, so that the materials are conveyed from the proximal end side of the screw body 37 to the distal end side.

[0285] Also, the third extruder for removing gaseous components from a kneaded material extruded by the second extruder 3 is not limited to a uniaxial extruder, but may be a biaxial extruder.

[0286] It is sufficient if the continuously operated, high-shear forming devices according to the embodiments use at least the first extruder for pre-kneading the raw materials and the second extruder for fully kneading them. The third extruder for removing gaseous material or volatile components can be omitted. If the third extruder is omitted, it is recommended to provide the intermediate section of the second extruder with at least one vent to remove a gaseous material or a volatile component from the currently kneaded material. List of reference symbols 3 extruders (second extruder) 20 housings 21 snail 34 Feed connection 36a discharge connection 37,200 snail bodies 54, 101 funding section 56, 57, 84, 85, 105, 107, 110, 111, 112 snail gear 60, 86, 115, 162, 172, 182, 203 passage O1 axis

Claims

[1] Extruder screw (21) for conveying a raw material while the raw material is kneaded, comprising: a screw body (37) having an axis (O1) extending in a conveying direction of the raw material and being rotated about the axis (O1); a conveying section (54) provided on an outer peripheral surface of the screw body (37) and including a screw flight (56), the screw flight (56) being designed to convey the raw material along the axis (O1) of the screw body (37) when the screw body (37) is rotated; and a plurality of passages (60) provided in the screw body (37) and allowing the raw material conveyed via the screw flight (56) to pass through them to the outer peripheral surface of the screw body (37), wherein the passages (60) are provided in positions deviating from the axis (O1) of the screw body (37), wherein the passages (60) have an inlet and an outlet open to the outer peripheral surface of the screw body (37), and the inlet and the outlet are separated from each other along the axis (O1) of the screw body (37), wherein the raw material flowing through the inlet into the passages (60) is returned through the outlet to the outer peripheral surface of the screw body (37), wherein the screw body (37) has a barrier section configured to increase the pressure of the raw material by restricting the raw material flow using the screw flight (56), and the inlet is positioned upstream of the barrier section. [2] Extruder screw (21) according to claim 1, wherein the passages (60) are designed to rotate about the axis (O1) when the screw body (37) is rotated. [3] Extruder screw (21) according to claim 1 or 2, wherein the screw body (37) has a cylindrical wall surface defining the passages (60), and the cylindrical wall surface is adapted to revolve about the axis (O1). [4] The extruder screw (21) according to any one of claims 1 to 3, wherein the passages (60) have a main passage communicating with the inlet and the outlet, and the main passage has a diameter smaller than a diameter of the inlet. [5] Extruder screw (21) for conveying raw material while the raw material is kneaded, comprising: a screw body (37) having an axis (O1) extending in a conveying direction of the raw material and being rotated about the axis (O1); a conveying section (54) provided on an outer peripheral surface of the screw body (37) and including a screw flight (56), the screw flight (56) being designed to convey the raw material along the axis (O1) of the screw body (37) when the screw body (37) is rotated; and a plurality of passages (60) provided in the screw body (37) and allowing the raw material conveyed via the screw flight (56) to flow in and return to the outer peripheral surface of the screw body (37), wherein the passages (60) are provided at intervals along the axis (O1) of the screw body (37) in positions which deviate from the axis (O1) of the screw body (37). [6] Extruder screw (21) according to claim 5, wherein the passages (60) are provided at intervals along the circumference of the screw body (37). [7] The extruder screw (21) according to any one of claims 1 to 6, further comprising a coolant passage configured to allow a coolant for cooling the screw body (37) to flow therein. [8] An extruder including the screw according to any one of claims 1 to 7 and adapted to knead a raw material using the screw to produce a kneaded product, the extruder comprising: a housing containing the screw such that the screw is rotatable; a feed port provided in the housing for feeding the raw material to the screw; and a discharge port provided in the housing to discharge the kneaded product. [9] Extrusion process comprising: Feeding raw material to a screw rotating in a casing and continuously conveying the raw material along an axis (O1) of the screw using a flight (56) formed on an outer peripheral surface of the screw; and guiding the raw material conveyed via the screw flight (56) to a plurality of passages (60) which rotate in the screw in accordance with the rotation of the screw and returning the raw material through the passages (60) to the outer peripheral surface of the screw when the screw is rotated, and Restricting the flow of raw material using a barrier portion provided in the screw to increase the pressure of the raw material, and introducing the pressure-increased raw material from the outer peripheral surface of the screw into the passages (60).

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