JPH11129247A - Surface roughening device for plastic pellets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for roughening the surface of a plastic pellet continuously and efficiently for a crystallization process. SOLUTION: There are provided a feeding part 3 and a mixing part 4. The feeding part 3 has a screw shaft 12 in a housing 11 for forcibly feed plastic pellets P introduced in the housing 11 to the mixing part. The mixing part 4 has a mixing cylinder 15 that is continuous to the housing 11 and which has a hexagonal cross section. The screw cylinder 15 has a mixing rotor rotating together with the screw 12. An elongated groove-like flaw-imparting hole is provided on an inner surface of the mixing cylinder. A claw is formed at a part of the edge of an opening of the flaw-imparting hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic pellet for roughening the surface of plastic pellets to prevent the pellets from sticking together in a crystallization process or sticking to processing equipment. The present invention relates to a surface roughening device.

[0002]

2. Description of the Related Art In the case of a crystalline resin such as polyethylene terephthalate or polyester, it is necessary to roughen the pellet surface before performing a crystallization treatment. Regarding this type of surface roughening treatment, Japanese Patent Application Laid-Open No. 4-110106 discloses a method in which a pellet is placed on a sieve formed of a wire mesh, and the surface of the pellet is roughened by applying vibration at normal temperature.
Furthermore, it is disclosed that a transportation pipe having an inner surface roughened, an elbow or a spiral pipe provided at an appropriate position in a pipeline are prepared, and pellets are passed through these pipelines to roughen the pellet surface. ing.

[0003] Japanese Patent Application Laid-Open No. 4-239607 discloses that the surface of pellets is roughened using a stirring device such as a Henschel mixer, a V blender, a ribbon blender, and a tumbler blender.

[0004]

The above conventional surface roughening apparatus employs a batch processing system except for the pipe feeding system, so that the apparatus becomes large in size and the cost for introducing it is high.
The time required for the surface roughening treatment is long, and the processing efficiency is low. The pipeline feeding method has an advantage that the surface roughening process can be performed continuously.
However, since the surface of the pellet is roughened by collision between the pellet fed at a constant speed and the pipe wall or collision between the pellet and the pipe wall when passing through an elbow or a spiral pipe, the reliability is increased. And the degree of surface roughening of the pellets passing through the pipe varies greatly. In order to perform sufficient surface roughening, it is necessary to repeatedly pass the pellets through the pipeline or increase the length of the pipeline, and in any case, there is a problem in that the processing efficiency is low.

It is an object of the present invention to perform a roughening treatment by forcibly stirring plastic pellets while feeding them, and rubbing the pellets against each other or rubbing them against a stirring cylinder. It is an object of the present invention to obtain a surface roughening apparatus capable of continuously and efficiently performing the surface treatment. Another object of the present invention is to significantly reduce the size of the entire apparatus as compared with a batch processing type or a pipe feeding type surface roughening apparatus, thereby significantly reducing the introduction cost and the installation space, and reducing the necessary amount. Therefore, in combination with a crystallization apparatus, the surface roughening treatment and the crystallization treatment can be performed continuously.

[0006]

The surface roughening apparatus according to the present invention comprises a feeding section 3 for forcibly feeding plastic pellets P in one direction, and a stirring section 4 provided continuously with the feeding section 3. It has. The feeding unit 3 includes a housing 11 having an input port 10 opened in a peripheral surface, and a screw shaft 12 that is driven to rotate in the housing 11 and forcibly feeds the plastic pellets P toward the stirring unit 4. . Stirrer 4
Comprises a stirring cylinder 15 fixed to the outlet end of the housing 11, a stirring rotor 17 rotationally driven in the stirring cylinder 15, and a tapered outlet cylinder 19 provided continuously with the stirring cylinder 15. Have. On the inner surface of the stirring cylinder 15, a group of wound bodies that promotes the surface of the plastic pellet P to be damaged is provided.

[0007] Specifically, the stirring cylinder 15 is formed in a polygonal cross section. One group of the injured body is a stirring cylinder 1
5 is formed with a damaged hole 24 penetrating in and out.

The stirring rotor 17 includes a rotor shaft 27 fixed to the screw shaft 12 and a plurality of stirring blades 28 projecting from the peripheral surface of the rotor shaft 27 in parallel with the axis of the rotor shaft 27.

A claw 25 is formed at the opening edge of the wound hole 24 so as to protrude a part of the opening edge toward the inner surface side of the agitating cylinder 15 to promote the damage of the surface of the plastic pellet P.

At the end of the outlet tube 19, an elbow-shaped outlet turning tube 20 is provided. The outlet turning cylinder 20 is provided so as to be rotatable around the cylinder axis with respect to the outlet pipe 19 and can be fixed by a fixing tool 31 at an arbitrary rotation turning position.

[0011]

In use, the plastic pellets P to be treated are introduced into the housing 11 through the inlet 10 and are forcibly fed to the stirring section 4 by the screw shaft 12. During this feeding, the plastic pellets P collide with each other and rub against each other, and furthermore, the spiral blade 12a of the screw shaft 12
And the inner surface of the housing 11 is rubbed against the surface, and the surface is damaged. The plastic pellets P that have reached the stirring section 4 are stirred around the rotor shaft 27 by the stirring rotor 17, collide with each other and rub against each other as in the case of feeding, and further rub against the stirring blade 28 and the rotor shaft 27 to form a surface. Hurt. In order to further promote the roughening of the stirring section 4, a group of wounded bodies (scratched holes) 24 for facilitating scratching of the surface of the plastic pellet P is provided on the inner surface of the stirring cylinder 15. The wound body 24 is formed by holes and projections, and the surface of the plastic pellet P is damaged by colliding with or rubbing against the wound body 24. The outlet cylinder 19 is tapered so as to provide an appropriate passage resistance and sufficiently apply the pressing force of the screw shaft 12 to the plastic pellet P.

As described above, the plastic pellet P in the stirring cylinder 15 receives the axial pressing force by the screw shaft 12 and the radial pressing force by the stirring rotor 17 at the same time. While changing it, it was gradually pushed out to the outlet tube 19, during which time there were countless abrasions and collision scratches on the pellet surface,
It is roughened evenly. That is, the roughening process can be forcibly and continuously performed forcibly. Since the surface roughening treatment is performed continuously, the processing efficiency can be remarkably improved.

The reason why the stirring cylinder 15 is formed to have a polygonal cross section is that the stirring gap between the stirring cylinder 15 and the stirring rotor 17 is changed between the side and the top of the inner surface of the cylinder, and the posture of the plastic pellet P is changed. This is because the position is changed more frequently to promote surface damage. A wound hole 24 penetrating a group of wound bodies through the cylinder wall in and out.
When formed, the processing of the injured body can be facilitated as compared with the case of the projection. In particular, when the stirring cylinder 15 is formed from a metal plate material, the stirring cylinder 15 can be formed at low cost. The wound hole 24 also functions as a sieve for taking out fine powder generated by the roughening to the outside of the stirring cylinder 15.

The reason why the plurality of stirring blades 28 are provided in parallel with the axis of the rotor shaft 27 is to stir and flow the plastic pellets P in the radial direction and to determine the degree of change in the position and posture of the pellets when passing through the stirring unit 4. This is to increase the surface roughness of the pellet surface with a shorter stirring distance.
This also helps to make the surface roughening device smaller.

Stirring cylinder 1 having wound hole 24
In 5, the surface can be roughened by the collision of the plastic pellet P with the opening edge of the wound hole 24, but if the claw 25 is protruded from the opening edge, the damage effect can be further enhanced.

The exit turning cylinder 20 provided at the end of the exit cylinder 19
Changes the passage resistance of the plastic pellet P passing through the outlet tube 19 to a large or small value, and changes the resistance to
It is provided in order to adjust the time required to pass through zero, and to sufficiently and sufficiently roughen the surface according to the type, size and hardness of the plastic pellets P.

[0017]

1 to 7 show an embodiment of a surface roughening apparatus according to the present invention. In FIG. 2, a surface roughening device includes a bearing 2 supporting a drive shaft 1 via a bearing.
And a feeding unit 3 for forcibly feeding the plastic pellets P to the right, a stirring unit 4 adjacent to the feeding unit 3, and the driving shaft 1 via a V-belt 5 and a pair of pulleys 6 and 7. The motor 8 is configured to include a motor 8 that is driven to rotate and a dust collector (not shown).

In FIG. 1, a feeding section 3 has an inlet 1 on its upper surface.
The housing 11 includes a hollow cylindrical housing 11 having an opening 0 and a screw shaft 12 housed in the housing 11. The inlet 10 protrudes above the housing 11, and a hopper 13 is mounted on the upper end thereof. The screw shaft 12 is the drive shaft 1
And a helical blade 12a for forcibly feeding the plastic pellets P toward the stirring section 4 on the shaft peripheral surface thereof. A slight gap is provided between the tip of the blade 12a and the inner wall of the cylinder of the housing 11. At the right end of the screw shaft 12, a rotor support shaft 12b for supporting a stirring rotor 17 described later protrudes.
From the support shaft 12b to the end of the drive shaft 1 on the pulley 7 side, a passage 14 for cooling air is provided along the axis.

The stirring section 4 includes a stirring cylinder 15 fixed to the outlet end of the housing 11, a dust collecting case 16 covering the outer surface of the stirring cylinder 15, a stirring rotor 17 and a delivery rotor 18 housed in the stirring cylinder 15. , An outlet cylinder 19 and an outlet turning cylinder 20 provided continuously with the stirring cylinder 15.

In FIG. 3, the stirring cylinder 15 is formed of a cylinder having a hexagonal cross section, and is formed by welding the opening edges of an equal-leg trapezoidal trough formed by bending a stainless steel plate. Flange 21 at regular intervals on cylinder circumference
The stirring cylinder 15 is fixed to the housing 11 together with the outlet cylinder 19 by screwing the bolts 22 inserted through the flanges 21 into the housing 11.

On each side wall of the stirring cylinder 15, a group of wound holes (wound bodies) 24 for facilitating damage to the surface of the plastic pellets P are provided. In the developed view shown in FIG. 4, the wound hole 24 is formed as an elongated groove-like hole, and its longitudinal center line is inclined by a predetermined angle θ with respect to the cylinder center. In each side wall, three rows of wound holes 24 are provided along the center axis of the cylinder, and the rows are arranged in a staggered manner in the circumferential direction. In this embodiment, the angle θ is set to 20 degrees. The imaginary line in FIG. 4 indicates the bending position.

In order to efficiently scratch the surface of the plastic pellet P on the inner surface of the cylinder, the damage hole 2
The claws 25 are provided in about half of the four. As shown in FIG.
Is formed by slightly projecting the right (or left) opening edge of the wound hole 24 toward the inner surface of the cylinder, and the claw tip is opposed to the rotation direction of the stirring rotor 17 and, conversely, the claw tip is rotated. Approximately the same number were provided along the direction. Wound hole 2
When the width of 4 is 1.2 mm and the length is 10 to 15 mm, the claw 2
The protruding dimension of the No. 5 from the inner surface of the cylinder was about 0.5 mm.
By the way, the diameter of the plastic pellet P is 3-5mm,
Its length is around 4mm.

The wound hole 24 also functions as a sieve for removing pellet powder generated by the surface roughening treatment.
In order to receive the pellet powder discharged from the stirring cylinder 15, the outer surface of the cylinder is hermetically covered with a dust collecting case 16. The dust collecting case 16 is connected to a cyclone-type dust collecting device and a suction fan through a connection port 26 provided on one side of the rear surface. Therefore, it is possible to prevent the pellet powder from adhering to the plastic pellet P subjected to the surface roughening treatment.

3 and 6, the stirring rotor 17 is used.
Is a rotor shaft 27 externally fitted and fixed to the rotor support shaft 12b.
And a stirring blade 28 protruding from two circumferential surfaces of the rotor shaft 27.
Consists of An empty chamber is provided on the inner surface of the rotor shaft 27, and the empty chamber communicates with the cooling passage 14 provided on the rotor support shaft 12b as shown in FIG. Stirring blade 28
Project from one end to the other end of the peripheral surface of the rotor shaft 27 in parallel with the axis of the rotor shaft 27. In FIG. 3, a certain gap is provided between the tip of the stirring blade 28 and the inner surface of the side wall of the stirring cylinder 15.

The delivery rotor 18 is provided at the end of the stirring rotor 17 on the outlet cylinder 19 side, and the delivery rotor 18 is screwed into the shaft end of the rotor support shaft 12b (see FIG. 1).
And fasten together. The delivery rotor 18 is formed of a truncated cone-shaped block, and delivery blades 30 protrude from the oblique side at two circumferential positions. The delivery blade 30 is located on the inner surface of the outlet cylinder 19 on the connection end side with the stirring cylinder 15, and pushes out the plastic pellets P in the outlet cylinder 19 toward the outlet turning cylinder 20.

The outlet cylinder 19 is a tapered cylindrical body, and is fixed together with the stirring cylinder 15 to the housing 11 with bolts 22. The tapered outlet cylinder 19 gives the plastic pellets P passing through the stirring cylinder 15 an appropriate passing resistance, and applies the pressing force of the screw shaft 12 to the plastic pellets P in the stirring section 4. Helps to work well.
The diameter of the outlet portion of the outlet tube 19 is smaller than the inner surface diameter of the housing 11.

The outlet diverting tube 20 is formed of an elbow-shaped cylinder, is fitted inside the outlet tube 19, is rotatably supported around the cylinder axis, and can be fixed by the fixture 31 at any deflecting position. As shown in FIG. 1, the pin 32 fixed to the outlet turning cylinder 20 is provided with a guide groove 33 provided on the lower half peripheral surface of the outlet pipe 19.
And the rotation of the outlet turning cylinder 20 can be changed forward and backward by 90 degrees, respectively, based on a state in which the outlet of the outlet turning cylinder 20 opens upward. The fixing tool 31 has an operating lever integrally provided at the upper end of the screw shaft, and the protruding end of the screw shaft screwed into the outlet tube 19 is pressed against the peripheral surface of the outlet turning tube 20 to fix the tube 20.

When the direction of the exit of the exit turning cylinder 20 is changed,
The resistance of the plastic pellet P passing through the outlet tube 19 can be changed. This passage resistance is greatest when the outlet opens upwards and gradually decreases as the outlet tilts forward or backward. When the pin 32 is removed,
As shown by the imaginary line in FIG. 1, the exit of the exit turning cylinder 20 can be set downward.

In use, the plastic pellets P are put into the housing 11 from the hopper 13 and forcedly fed into the stirring cylinder 15 by the screw shaft 12. The pellet group that has reached the stirring cylinder 15 is pressed by the feeding force of the screw shaft 12, and
Since the mixture is stirred in the radial direction at 7, the surfaces are rubbed against each other and rub against each other, thereby damaging the surface. Further, the pellet group is pressed against the stirring cylinder 15 with the flow during stirring, and comes into contact with the wound hole 24 and the claw 25 to scratch the surface. The scratches are larger and deeper than the scratches formed by rubbing each other. of course,
Similar damage is also caused by contact with the screw shaft 12 and the stirring rotor 17.

As described above, the surface of the plastic pellet P is roughened while passing through the feeding section 3 and the stirring section 4 so that the surface is not glossy or the exit turning cylinder is whitened. Released from 20. In the crystallization treatment step of the next step, the plastic pellets P thus roughened are fused together and solidified in a lump,
Alternatively, sticking to the processing equipment can be reliably prevented.

The plastic pellets P are continuously charged and are forcibly and continuously subjected to a roughening treatment by a surface roughening device. Therefore, the surface roughening treatment of the pellet surface can be efficiently performed, and the processing ability is remarkably improved as compared with the conventional processing apparatus. As shown in FIG. 7, the present inventor has separately developed a pellet crystallization apparatus 35 in which the crystallization processing has been improved from batch processing to continuous processing. However, the crystallization apparatus 35 is combined with the surface roughening apparatus described above. When used, a series of operations from the surface roughening treatment to the crystallization treatment could be continuously and efficiently performed.

In FIG. 7, the pellet crystallization device 35 comprises:
On the upstream side of the belt conveyor 36, a hopper 37 for receiving the roughened plastic pellets is provided, and a regulating plate 38 provided at an outlet of the hopper 37 and side plates 39 provided before and after the upper surface of the belt conveyor 36 are provided. The thickness and width of the pellet layer on the conveyor are made uniform. An anode plate 40 is provided above the middle part of the belt conveyor 36, and a cathode plate 41 is provided below the belt conveyor 36. By passing a high-frequency voltage between the both plates 40, 41, the anode plate 40 passes between the plates 40, 41. The crystallization is performed by the dielectric heating action of the plastic pellet itself.

The surface roughening device described in the above embodiment can be partially modified as follows. The stirring cylinder 15 can be formed in a polygonal cross section other than a hexagon,
If necessary, it can be changed to a circular or oval cross section. The injured body can be formed by a group of projections instead of the injured hole 24, or may be formed by a hole or a hole with a bottom. The stirring blade 28 of the stirring rotor 17 can be provided with a large number of blades dispersed and protruded in the axial direction or the circumferential direction, and can be slightly inclined with respect to the center axis of the rotor if necessary.

[0034]

According to the surface roughening apparatus of the present invention, the plastic pellets P are forcibly fed by the screw shaft 12 so that the pellets are pressed against each other in the stirring cylinder 15 and further stirred by the stirring rotor 17. And rub the pellets together or stir cylinder 1
The pellet was pressed against the wound body provided on the inner surface of No. 5 so that the pellet surface could be forcibly roughened. Therefore, the surface roughening treatment of the pellet surface can be performed continuously and evenly efficiently, and the processing time and the processing amount per unit time can be greatly improved as compared with the conventional apparatus of the batch processing method. Compared with the conventional apparatus, the entire apparatus can be significantly reduced in size and the introduction cost can be significantly reduced. Installation space is also small.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA in FIG.

FIG. 2 is a plan view of the surface roughening device.

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a development view of a stirring cylinder.

FIG. 5 is a sectional view taken along line CC in FIG. 4;

FIG. 6 is a perspective view of a stirring rotor.

FIG. 7 is a schematic front view showing an example of use of the surface roughening device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 Feeding part 4 Stirring part 10 Input port 11 Housing 12 Screw shaft 15 Stirring cylinder 17 Stirring rotor 19 Exit tube 24 Damaged hole (damaged body) 25 Claw

Claims (5)

[Claims] 1. A feed section 3 for forcibly feeding plastic pellets P in one direction, and a stirring section 4 provided continuously with the feed section 3. The feed section 3 has a peripheral surface. The housing 11 has an opening 10, and a screw shaft 12 that is driven to rotate in the housing 11 to forcibly feed the plastic pellets P toward the stirring unit 4. A stirring cylinder 15 fixed to an outlet end of the stirring cylinder, a stirring rotor 17 rotatably driven in the stirring cylinder 15, and a tapered outlet cylinder 19 provided continuously with the stirring cylinder 15; A plastic pellet P is placed on the inner surface of the stirring cylinder 15.
A surface roughening device for plastic pellets, provided with a group of wound bodies that promotes scratching of the surface of the plastic pellet. 2. The agitation cylinder 15 is formed in a polygonal cross section, and a group of wound bodies is formed by a wound hole 24 penetrating a wall surface of the agitation cylinder 15 in and out. Surface roughening device for plastic pellets. 3. The stirring rotor 17 includes a rotor shaft 27 fixed to the screw shaft 12, and a plurality of stirring blades 28 projecting from a peripheral surface of the rotor shaft 27 in parallel with the axis of the rotor shaft 27. The surface roughening device for plastic pellets according to claim 1 or 2. 4. A claw 25 is formed at the opening edge of the wound hole 24 so that a part of the opening edge protrudes toward the inner surface of the stirring cylinder 15 to promote the surface of the plastic pellet P to be damaged. Item 4. A surface roughening device for plastic pellets according to item 2 or 3. 5. An elbow-shaped outlet diverting tube 20 is provided at the end of the outlet tube 19, and the outlet diverting tube 20 is rotatable around the cylinder axis with respect to the outlet tube 19 and can be arbitrarily selected. The surface roughening device for plastic pellets according to claim 2, 3, or 4, wherein the surface fixing device is provided so as to be fixed by the fixing tool 31 at the rotational turning position.