JP2518690Y2 - Screw structure - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw structure of an extruder for resin materials, and more particularly to a new improvement for obtaining a high kneading / dispersing ability by using a flight extending parallel to the axial direction.

[0002]

2. Description of the Related Art As a screw structure for kneading / dispersing an extruder for a resin material which has been conventionally used, a structure shown in FIG. 3 is adopted as an example of a twin-screw extruder. That is, what is indicated by reference numeral 1 in FIG. 3 is a cylinder having a material supply hole 1a and a vent hole 1b, and inside the bore 2 of this cylinder 1, a feed screw 3a, a kneading / dispersing screw portion 3b, and A screw 3 having a discharge part screw 3c is rotatably provided.

The kneading / dispersing screw portion 3b has a structure in which a plurality of kneading disks 4 and sealing disks 5 are axially laminated and combined. Therefore, the material such as polypropylene resin supplied from the material supply hole 1a was conveyed by the feed section screw 3a, melted and kneaded by the kneading / dispersion screw section 3b, and discharged from the discharging section screw 3c to the outside. Further, in the single-screw extruder, a dullage type or a Maddock type screw is adopted.

[0004]

Since the conventional screw structure is constructed as described above, there have been the following problems. That is, the conventional screw structure stops or even reverses the flow of material, so that a strong shearing action is exerted on the material for a longer time between the flight of the screw and the inner surface of the cylinder. . As a result, the material is sufficiently kneaded, but on the other hand, a higher internal pressure is generated inside the extruder, which may cause an abnormal increase in the material temperature or an uneven distribution. This has been one of the causes of reducing the physical properties of resin products and making them non-uniform.
In addition, the processing capacity was low by stopping the flow or reversing the flow.

The present invention has been made in order to solve the above problems, and provides a screw structure in which the temperature rise is reduced to improve the physical property quality and make it uniform, thereby improving the processing capacity. The purpose is to do.

[0006]

The screw structure according to the present invention is a screw structure comprising a screw having a kneading / dispersing screw part that rotates in a cylinder to knead / disperse a material. A plurality of first members extending in parallel with the axial center direction of the kneading / dispersing screw portion and arranged at intervals in the axial circumferential direction.
A flight and a plurality of second flights formed in the kneading / dispersion screw portion and extending in parallel to the axial direction and arranged at intervals in the axial circumferential direction, each of the second flights The first flight and the second flight are located between the first flights as viewed from the axial direction, and the first flight and the second flight are separated from each other at a distance W in the axial direction.
A slope having a helix angle is formed on the downstream side of the first flight and the second flight, and the slope causes the slope only when the screw rotates counterclockwise when viewed from the upstream side in the material flow direction. The structure is such that a force for moving the material along the material flow direction is applied.

[0007]

[Operation] In the screw structure according to the present invention, kneading and
The first and second flights extending in the axial direction of the dispersion screw portion and separated from each other are out of phase with each other in the axial circumferential direction, and the first flight is located between the second flights as viewed from the axial direction, The material, such as a polymer, which has advanced between the first flights, positively passes through the gap between the flight and the cylinder due to the resistance of the second flight, and undergoes a large shearing action at that time. However, since the first flight and the second flight are provided separately from each other, there is no effect of stopping the flow of the material between the two flights. Furthermore, since a slope with a helix angle is formed on the downstream side of each flight, the material that passes through the flight is given a force that moves in only one direction of rotation of the screw, without causing abnormal internal pressure and local heat generation. It is possible to carry out uniform kneading and dispersion.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the screw structure according to the present invention will be described in detail below with reference to the drawings. It should be noted that the same or equivalent parts as those of the conventional example are designated by the same reference numerals for description. 1 and 2 show a screw structure according to the present invention.
FIG. 1 is a sectional configuration diagram, and FIG. 2 is a transverse sectional view of FIG.

In FIG. 1 and FIG. 2, the reference numeral 1 is a cylinder in which the screw 3 is rotatably incorporated.
The screw 3 is composed of one axis or two axes.

A kneading / dispersing screw section 3 provided on the screw 3 for kneading / dispersing a material such as a polymer.
b extends parallel to the axial center direction A and also extends in the axial circumferential direction B.
A plurality of first flights 11 formed at intervals via a groove 10 having a space C, and the first flights 1
1 and a plurality of second flights 12 formed in parallel with the axial direction A and separated from each other via a groove 10a having the interval C in the axial circumferential direction B. .

The respective flights 11 and 12 are separated from each other in a non-flight portion 20 having a width W in the axial direction, and the second flights 12 when viewed from the axial direction A, the first flights. Since the flights 11 and 12 are located in the groove 10 between them, the flights 11 and 12 are arranged in a state of being out of phase with each other in the axial direction B. In addition,
The width W is 1/10 to 3/10 of the screw diameter.

The downstream side in the material flow direction D in which the material such as the polymer in each of the flights 11 and 12 flows is shown in FIG.
And a slope 13 having a twist angle α is formed,
The slope 13 is configured to push the material in the downstream direction. That is, only when the screw 3 is rotated counterclockwise when viewed from the upstream side in the material flow direction D, the inclination angle α is provided so that a force for moving the material along the material flow direction D is given by the slope 13. Are formed.

Next, in the above-mentioned structure, a case will be described in which the material such as the polymer is actually kneaded and dispersed by using the kneading and dispersing screw portion 3b. First, screw 3
Is rotated counterclockwise when viewed from the upstream side in the material flow direction D, the flights 11 and 12 are parallel to the axial direction A, so that they do not have the ability to send the material downstream, but the upstream feed section The material flows between the flights 11 or 12 by the conveying force of the screw 3a. First, the material that has traveled through the grooves 10 between the first flights 11 is
The resistance of the second flight 12 corresponding to 0 positively passes through the gaps 1a between the flights 11 and 12 and the cylinder 1, and receives a large shearing action at that time to grind the aggregates in the material. However, flights 11 and 12
The presence of the non-flight portion 20 in between does not subject the material to significant flow resistance.

Further, since the slope 13 is formed on the downstream side of the first flight 11, the respective flights 11, 12 are
The material located in the non-flight portion 20 between is subjected to a force to move in the downstream direction by this slope 13, so that the material is sufficiently dispersed and is sent to the next second flight 12 side,
It is possible to prevent abnormal internal pressure in the cylinder 1 and local heat generation and perform uniform kneading / dispersion.

Next, an experimental example in which the applicant of the present invention actually kneads and disperses using the above-mentioned kneading and dispersing screw section 3b will be described. The processing material is PP pellets MFR = 8, talc average particle diameter 1. 5 μ (40% by weight), and the result of supplying each from the supply port of the cylinder 1 by the quantitative feeder,
The following experimental data were obtained.

[Table 1]

As is clear from the above experimental data, a significant improvement in processing capacity (discharge amount) and energy consumption (KWH / Kg) can be seen in comparison with the conventional structure, and high content, ultrafine particles, low It was found to be optimal when used for kneading and dispersing the bulk density filler.

In the above-mentioned experimental example, a case was described in which one pair of flights 11 and 12 were formed in the kneading / dispersion screw section 3b along the axial direction, but the number of flights 11 and 12 was set to one pair. Needless to say, the number of flights can be formed to be three or four, and the flights can be used with staggered phases.

[0018]

Since the screw structure according to the present invention is constructed as described above, the following effects can be obtained. That is, since kneading is performed using a kneading / dispersing screw part that is formed in parallel with the axial direction of the screw and arranged so that the phases are different from each other in the axial circumferential direction, and that has a slope, Compared with the screw structure, the processing capacity can be improved by about 50%, the energy consumption can be reduced by about 10%, and the resin temperature can be reduced by about 5%, and kneading and dispersion can be performed without causing local heat generation. You can In addition, it becomes possible to improve the physical properties of the product and obtain a uniformly stable product.

[Brief description of drawings]

FIG. 1 is a sectional view showing a screw structure according to the present invention.

2 is a cross-sectional view of FIG.

FIG. 3 is a cross-sectional configuration diagram showing a conventional screw structure.

[Explanation of symbols]

 1 Cylinder A Axial direction B Axial circumferential direction C Interval D Material flow direction 3b Kneading / dispersion screw part 11 First flight 12 Second flight 13 Slope α Twist angle

Claims (1)

(57) [Scope of utility model registration request] 1. A screw structure comprising a screw (3) having a kneading / dispersing screw section (3b) adapted to knead / disperse materials by rotating in a cylinder (1),
Along with the axial direction (B) of the kneading and dispersing screw portion (3b) formed in the dispersing screw portion (3b) and extending in parallel with the axial direction (A).
A plurality of first flights (11) arranged at intervals (C)
And the first flight of the kneading / dispersion screw section (3b)
A plurality of second flights (12) which are formed apart from (11) and extend parallel to the axial direction (A) and are arranged at intervals (C) in the axial circumferential direction (B). Prepare for each second flight
(12) is the first flight when viewed from the axial direction (A)
The first flight (11) and the second flight (12) are located between (11) and are separated from each other at a distance (W) in the axial direction (A). And the second flight (1
A slope (13) having a twist angle (α) is formed on the downstream side of 2), and when the screw (3) rotates counterclockwise as viewed from the upstream side in the material flow direction (D) of the material. only,
A screw structure characterized in that a force for moving the material along the material flow direction (D) is applied by the inclined surface (13).