JP2019043043A - Screw and extruder - Google Patents

Abstract

To provide a screw and an extruder which can improve a productivity while maintaining a good quality of a plastic elastomer.SOLUTION: A screw 2 has a spiral blade 5 for extruding a plastic elastomer G while kneading. The screw 2 includes a kneading promotion region 6. The kneading promotion region 6 includes a first promotion section 7 in which a spiral wing 5 is formed by double thread, a second promotion section 8 in which the spiral wing 5 is formed by a single thread on a downstream side of the first promotion section 7 in an extrusion direction A, and a third promotion section 9 in which the spiral wing 5 is formed by a double thread on a downstream side of the second promotion section 8 in the extrusion direction A. In the first promotion section 7 and the third promotion section 9, a plurality of cutouts 10 are formed in the spiral wing 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a screw and an extruder for extruding while kneading a plastic elastomer.

  In recent years, in an extruder including a screw for extruding while a plastic elastomer is kneaded, it has been required to increase productivity by increasing the amount of the plastic elastomer to be discharged. Therefore, the following Patent Document 1 proposes an extruder that increases the productivity of the plastic elastomer by increasing the discharge amount of the plastic elastomer by constituting the spiral blade of the screw with a double thread and a single thread. ing.

Japanese Patent Laid-Open No. 2004-009403

  However, the extruder of Patent Document 1 has a problem that when the discharge amount of the plastic elastomer is increased, the kneading state becomes insufficient and the quality is deteriorated. Therefore, in the technical field of extruders, further improvement has been demanded in order to achieve both the productivity and quality of the discharged plastic elastomer.

  The present invention has been devised in view of the above circumstances, and has as its main purpose to provide a screw and an extruder that can improve the productivity while maintaining good quality of a plastic elastomer. .

  The present invention is a screw having a spiral blade for extruding a plastic elastomer while kneading, and includes a kneading promotion region, wherein the kneading promotion region is a first promotion section in which the spiral blade is formed by a double thread. A second acceleration section in which the spiral blade is formed with a single thread on the downstream side in the extrusion direction of the first acceleration section; and a double thread on the downstream side in the extrusion direction of the second acceleration section. The first promotion section and the third promotion section are formed with a plurality of notches in the spiral wing.

  In the screw of the present invention, it is preferable that a lead angle of the spiral blade in the second promotion section is larger than a lead angle of the spiral blade in the first promotion section and the third promotion section.

  The screw of the present invention preferably includes a preliminary kneading region for sending the elastomer to the kneading promoting region upstream of the kneading promoting region in the extrusion direction.

  In the screw according to the present invention, the preliminary kneading region includes a first preliminary section in which the spiral blade is formed by a multi-thread screw, and the spiral blade is formed by a single thread in the downstream side in the extrusion direction of the first preliminary section. The second preliminary section is preferably included.

  In the screw of the present invention, it is preferable that a plasticizing region for shearing the elastomer is included on the downstream side in the extrusion direction of the kneading promoting region.

  In the screw of the present invention, the plasticizing region includes a first plastic section in which the spiral blade is formed by a single thread, and a barrier having a lead angle of 90 ° on the downstream side in the extrusion direction of the first plastic section. It is desirable that the second plastic section includes a third plastic section in which the spiral blade is formed by a double thread on the downstream side in the extrusion direction of the second plastic section.

  In the screw of the present invention, it is preferable that the second plastic section includes a plurality of barriers.

  In the screw of the present invention, the height of the barrier is preferably smaller than the height of the spiral blade.

  The present invention is an extruder including the above-described screw and a barrel in which the screw is disposed, and the barrel is formed on the spiral blades of the first promotion section and the third promotion section. It includes a plurality of pins inserted into the notch.

  In the extruder according to the present invention, the barrel includes an inlet for charging the elastomer, and the inlet is in a first preliminary section formed in a preliminary kneading area upstream of the kneading promoting area in the extrusion direction. Is desirable.

  In the screw according to the present invention, the kneading promotion region includes a first promotion section in which the spiral blade is formed by two threads, and the spiral blade is formed by a single thread on the downstream side in the extrusion direction of the first promotion section. The second accelerating section includes a third accelerating section in which the spiral blade is formed by a double thread on the downstream side in the extrusion direction of the second accelerating section. Such a kneading promotion region can increase the discharge amount of the plastic elastomer and improve the productivity.

  In the screw of the present invention, the first accelerating section and the third accelerating section are formed with a plurality of notches in the spiral blade. Such a screw, together with a pin inserted into the notch, can promote shearing of the plastic elastomer and improve its quality.

It is a side view which shows one Embodiment of the extruder of this invention. It is a side view of the screw of FIG.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view showing an extruder 1 according to this embodiment. As shown in FIG. 1, the extruder 1 of the present embodiment includes a screw 2 for extruding the plastic elastomer G in the extrusion direction A while kneading the plastic elastomer G, and a barrel 3 in which the screw 2 is arranged. . Here, the plastic elastomer G includes, for example, an unvulcanized rubber or a thermoplastic elastomer.

  The screw 2 includes a screw shaft 4 and a spiral blade 5 that protrudes from the screw shaft 4 to the outside in the radial direction of the screw 2. The spiral blade 5 is for extruding the plastic elastomer G while kneading, and is formed, for example, as a single thread, a double thread, or a multiple thread.

  Here, the single thread is an aspect having one spiral blade 5 in the same portion in the axial direction of the screw shaft 4. The double thread is an aspect in which two spiral blades 5 are provided in the same portion in the axial direction of the screw shaft 4. Furthermore, a multi-thread screw is an aspect having two or more spiral blades 5 in the same axial portion of the screw shaft 4. A double thread is an aspect of a multi-thread.

  FIG. 2 is a side view of the screw 2 of FIG. In FIG. 2, the screw 2 is shown partially omitted. As shown in FIGS. 1 and 2, the screw 2 of the present embodiment includes a kneading promotion region 6. The kneading promotion region 6 preferably includes a plurality of sections 7 to 9.

  The kneading promotion region 6 of the present embodiment includes a first promotion section 7, a second promotion section 8 on the downstream side in the extrusion direction A of the first promotion section 7, and a third on the downstream side in the extrusion direction A of the second promotion section 8. The promotion section 9 is included. Such a kneading promotion region 6 can increase the discharge amount of the plastic elastomer G and improve the productivity.

  As for the 1st acceleration | stimulation area 7, it is desirable for the spiral blade 5 to be formed with a double thread. In the first promotion section 7 of the present embodiment, a plurality of notches 10 are formed in the spiral blade 5. Such a 1st promotion area 7 can accelerate | stimulate the shear of the plastic elastomer G with the pin 13 mentioned later inserted in the notch part 10, and can improve the quality.

  In the second promotion section 8, it is desirable that the spiral blade 5 is formed with a single thread on the downstream side in the extrusion direction A of the first promotion section 7. Such a 2nd promotion area 8 can increase the discharge amount of the plastic elastomer G, and can improve the productivity.

  In the third promotion section 9, it is desirable that the spiral blade 5 is formed by a double thread on the downstream side in the extrusion direction A of the second promotion section 8. In the third promotion section 9 of the present embodiment, a plurality of notches 10 are formed in the spiral blade 5. Such a third promoting section 9 can promote shearing of the plastic elastomer G together with a pin 13 to be described later inserted into the notch 10 and improve its quality.

  Next, in the extruder 1 of this embodiment, a more preferable aspect for achieving both productivity and quality of the plastic elastomer G will be described. As shown in FIG. 1, the barrel 3 is formed in, for example, a substantially cylindrical shape having a substantially constant inner diameter. The barrel 3 preferably includes an input port 11 through which the plastic elastomer G is input and an output port 12 through which the kneaded elastomer G is discharged.

  The barrel 3 preferably includes a plurality of pins 13 that are inserted into the notches 10 formed in the spiral blades 5 of the first promotion section 7 and the third promotion section 9. In the barrel 3 of this embodiment, a plurality of pins 13 are inserted into one notch 10 of the spiral blade 5. It is desirable that the amount of insertion of the pin 13 can be changed as appropriate. Such a pin 13 can promote the shearing of the plastic elastomer G and improve its quality.

  The screw 2 is preferably rotated in one direction by a drive unit 14 disposed on the upstream side in the extrusion direction A of the barrel 3. The rotational speed of the screw 2 can be appropriately adjusted by the drive unit 14. Such a screw 2 can easily change the rotation speed in accordance with the operating state of the extruder 1.

  In the screw 2 of the present embodiment, in the first promotion section 7 of the kneading promotion region 6, for example, notches 10 are formed at four locations on the spiral blade 5. Moreover, the 3rd promotion area 9 is formed with the notch part 10 in three places of the spiral blade 5, for example. The number of locations where the notches 10 are formed is not limited to this, and can be appropriately changed according to the type of the plastic elastomer G to be extruded.

  As shown in FIG. 2, the lead angle θ2 of the spiral blade 5 in the second promotion section 8 is the lead angle θ1 of the spiral blade 5 in the first promotion section 7 and the lead angle θ3 of the spiral blade 5 in the third promotion section 9. Is desirable. The lead angle θ1 of the first promotion section 7 of the present embodiment is substantially equal to the lead angle θ3 of the third promotion section 9. Such a kneading promoting region 6 can increase the discharge amount of the plastic elastomer G and improve the productivity.

  As shown in FIGS. 1 and 2, the screw 2 of the present embodiment includes a preliminary kneading region 15 that sends the plastic elastomer G to the kneading promoting region 6 on the upstream side in the extrusion direction A of the kneading promoting region 6. . The pre-kneading region 15 preferably includes a plurality of sections 16 to 17.

  The preliminary kneading region 15 of the present embodiment includes a first preliminary section 16 into which the plastic elastomer G is charged from the charging port 11 of the barrel 3, and a second preliminary section 17 on the downstream side in the extrusion direction A of the first preliminary section 16. Is included. In other words, it is desirable that the plastic elastomer G is introduced into the first preliminary section 16 formed in the preliminary kneading region 15 at the input port 11 of the barrel 3.

  As for the 1st preliminary | backup area | region 16, it is desirable for the spiral blade 5 to be formed with a multi-threaded screw. Such a first preliminary section 16 can reliably feed the plastic elastomer G that has been charged into the barrel 3 without overflowing from the charging port 11.

  In the second preliminary section 17, the spiral blade 5 is preferably formed by a single thread on the downstream side in the extrusion direction A of the first preliminary section 16. Such a second preliminary section 17 can increase the discharge amount of the plastic elastomer G and improve the productivity.

  The screw 2 of the present embodiment includes a plasticizing region 18 that shears the plastic elastomer G on the downstream side in the extrusion direction A of the kneading promoting region 6. The plasticized region 18 preferably includes a plurality of sections 19-21.

  The plasticizing region 18 of the present embodiment includes a first plastic section 19 on the downstream side in the extrusion direction A of the kneading promotion region 6, a second plastic section 20 on the downstream side in the extrusion direction A of the first plastic section 19, and a second plastic section. And a third plastic section 21 downstream of the section 20 in the extrusion direction A.

  In the first plastic section 19, the spiral blade 5 is preferably formed by a single thread on the downstream side in the extrusion direction A of the kneading promotion region 6. The first plastic section 19 can increase the discharge amount of the plastic elastomer G and improve the productivity. In the first plastic section 19, the spiral blade 5 may be formed by a double thread.

  The second plastic section 20 includes at least one barrier 22 in the present embodiment in the extrusion direction A downstream of the first plastic section 19. For example, the barrier 22 has a lead angle of 90 °. The barrier height H1 is preferably smaller than the height H2 of the spiral wing. The second plastic section 20 can promote the shearing of the plastic elastomer G and improve the quality thereof. Note that the second plastic section 20 may include a plurality of barriers 22.

  In the third plastic section 21, it is desirable that the spiral blade 5 is formed by a double thread on the downstream side in the extrusion direction A of the second plastic section 20. Such a third plastic section 21 can stably discharge the plastic elastomer G from the discharge port 12 of the barrel 3, and can achieve both productivity and quality of the plastic elastomer G.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to the above-mentioned embodiment, It can deform | transform and implement in a various aspect.

2 Screw 5 Spiral blade 6 Kneading promotion area 7 First promotion section 8 Second promotion section 9 Third promotion section 10 Notch

Claims (10)

A screw having a spiral blade for extruding while kneading a plastic elastomer,
Including a kneading promotion area,
The kneading promotion region includes a first promotion section in which the spiral blade is formed by a double thread and a second promotion section in which the spiral blade is formed by a single thread on the downstream side in the extrusion direction of the first promotion section. And on the downstream side in the extrusion direction of the second promotion section, the spiral blade includes a third promotion section formed by a double thread,
In the first promotion section and the third promotion section, a plurality of notches are formed in the spiral wing.
screw.   2. The screw according to claim 1, wherein a lead angle of the spiral blade in the second promotion section is larger than a lead angle of the spiral blade in the first promotion section and the third promotion section.   3. The screw according to claim 1, further comprising a preliminary kneading region for sending the elastomer to the kneading promoting region on the upstream side in the extrusion direction of the kneading promoting region.   The preliminary kneading region includes a first preliminary section in which the spiral blade is formed of multiple threads, and a second preliminary section in which the spiral blade is formed of a single thread on the downstream side in the extrusion direction of the first preliminary section. The screw according to claim 3, comprising:   The screw according to any one of claims 1 to 4, further comprising a plasticizing region that shears the elastomer at a downstream side in the extrusion direction of the kneading promoting region.   The plasticizing region includes a first plastic section in which the spiral blade is formed by a single thread, and a second plastic section including a barrier having a lead angle of 90 ° on the downstream side in the extrusion direction of the first plastic section, The screw according to claim 5, wherein the spiral blade includes a third plastic section formed of a double thread on the downstream side in the extrusion direction of the second plastic section.   The screw according to claim 6, wherein the second plastic section includes a plurality of barriers.   The screw according to claim 6 or 7, wherein a height of the barrier is smaller than a height of the spiral wing. An extruder comprising the screw according to any one of claims 1 to 8 and a barrel for arranging the screw therein.
The barrel includes a plurality of pins inserted into the notches formed in the spiral wings of the first promotion section and the third promotion section,
Extruder. The barrel includes a slot for charging the elastomer,
10. The extruder according to claim 9, wherein the charging port inputs the elastomer into a first preliminary section formed in a preliminary kneading area upstream of the kneading promoting area in the extrusion direction.

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