JP3945802B2 - Pelletizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pelletizer for cutting a resin material formed in a strand shape into pellets.
[0002]
[Prior art]
In general, a thermoplastic resin material is blended with a colorant and various additives for easy supply to a molding machine, kneaded, extruded into a string-like strand, cooled with water, and then cut with a pelletizer. The pellet is about 5 mm and is commercially available. Further, the polymerized molten resin is extruded from a perforated die using an extruder or a gear pump, and the stranded strand is cooled and then cut with a pelletizer to produce pellets. Such pelletizers sandwich a cooled strand or strands with two take-up rolls and continuously feed them onto the strand receiving chute surface and / or the strand running surface, and fixed blades and rotating blades attached to the tips of the strands. It is structured to cut between.
[0003]
The pellets cut in this way are discharged from the pellet product discharge chute, but some of the pellets move along with the centrifugal force of the rotating blades and adhere to the valleys of the rotating blades. It passes through the space and scatters at the strand cutting point between the rotary blade and the fixed blade. For this reason, it has been practiced to attach a baffle plate to the rotary blade cover, but it is difficult to capture all the scattered pellets with the baffle plate and discharge them to the product discharge chute, and the scattered pellets are cut again. (So-called twice cutting), chipped pellets are generated, scattered on the chute where the strand travels, and some are scattered to the outside, resulting in deterioration of pellet shape, generation of defective products, and extrusion workability with scattered pellets Was the cause of the decline.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a pelletizer that controls the flow of pellets scattered in the pelletizer to prevent the pellets from being cut twice and prevents the pellets from scattering outside the pelletizer.
[0005]
[Means for Solving the Problems]
The present invention has been made in order to achieve the above object, and in a pelletizer for cutting a strand fed from a take-up roll between a rotary blade and a fixed blade, the rotary blade is provided inside the rotary blade cover. A pelletizer is characterized in that a guide plate for guiding scattered pellets is attached from the center of the width toward both sides.
[0006]
That is, the present invention provides (1) a pelletizer for cutting a strand sent from a take-up roll through a strand receiving chute between a rotary blade and a fixed blade, and pellets scattered in the rotary blade cover At least one guide that is symmetrical in the direction of both sides of the rotary blade cover from the center of the width of the rotary blade and that is formed in an inverted V shape with respect to the rotational direction of the rotary blade. The present invention relates to a pelletizer characterized in that a plate is provided inside a rotary blade cover.
[0008]
(2) The guide plate is mounted on the inner side of the rotary blade cover from the intersection of the tangent line that contacts the outer periphery of the rotary blade parallel to the running surface of the strand and the inner surface of the rotary blade cover to the tip of the rotary blade cover. The present invention relates to the pelletizer described in (1) above.
[0009]
(3) The guide plate according to (1) or (2) , wherein the guide plate is attached so that a gap between the tip of the rotary blade and the guide plate is 2 mm to 10 mm.
[0010]
(4) Moreover, it is related with the pelletizer in any one of said (1)-(3) characterized by providing an opening part in the strand running part lower surface of a strand acceptance chute.
[0011]
(5) The pelletizer according to any one of (1) to (4) above, wherein a plate for preventing the pellets from scattering outside is provided in a gap between the outer side of the rotary blade cover and the outer side of the take-up roller cover.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic longitudinal sectional view showing an outline of an embodiment of a pelletizer according to the present invention. FIG. 2 is a schematic top view of the pelletizer of the present invention, in which two guide plates provided inside the rotary blade cover are indicated by broken lines, and the rotary blade and the take-up roller are indicated by two-dot broken lines.
FIG. 3 is a partially enlarged view showing the inner surface of the rotary blade cover, and shows that guide plates are provided in the direction of both sides of the cover from the center of the rotary blade cover to the left and right.
[0013]
In FIG. 1, a single strand or a plurality of strands extruded from an extruder or the like are introduced into a chute 2 by a guide roller 1 and taken up by a take-up roller composed of an upper roller 3 and a lower roller 4. And sent to a cutting section 7 composed of a rotary blade 5. The strand to be delivered is cut into a predetermined length by the fixed blade 6 and the rotary blade 5 at the cutting portion 7 and pelletized. The rotary blade 5 has a gear-like blade and rotates clockwise in the figure. The upper roller 3 and the rotary blade 5 are provided with a cover mainly from the viewpoint of safety. The rotary blade cover 8 is mounted at the fixed portion 14 of the rotary blade cover so that it can be opened and opened freely for maintenance inspection and cleaning of the rotary blade, adjustment of the clearance between the fixed blade and the rotary blade, and the like. The tip portion B of the rotary blade cover corresponding to the fixed portion is disposed in the upper part of the strand introduction port 11 in the vicinity of the cutting portion 7. A rotary blade cover holding jig 15 is provided so that the rotary blade cover 8 does not move easily due to vibration or the like. In FIG. 1, a state where the rotary blade cover 8 is opened upward is indicated by a broken line.
[0014]
The strand delivered from the take-up roll is cut into a desired length and pelletized between the rotary blade and the fixed blade. Most of the pellets are guided to the product discharge chute 18, but some of the cut pellets move while adhering to the blades and valleys of the rotary blades having a plurality of blades, and the upper part in the rotary blade cover It moves with the rotation of the rotary blade. A baffle plate (doctor blade) 10 is provided on the inner surface 81 (illustrated in FIG. 3) of the rotary blade cover 8 to supplement these scattered pellets. There are scattered pellets that cannot be captured only by the baffle plate 10, which moves through the gap between the rotary blade and the rotary blade cover, and is cut again by the cutting portion 7.
[0015]
In the present invention, at least one guide plate 9 and / or 91 that captures scattered pellets and guides them to both sides of the rotary blade cover 8 inside the rotary blade cover 8 (indicated by 9, 91 in FIGS. 2 and 3). A state in which two guide plates are provided is shown). As shown in FIGS. 2 and 3, the guide plate is arranged on the rotary blade cover inner surface 81 so as to guide the scattered pellets from the center of the damped rotary blade to the gaps on both sides of the rotary blade cover 8. It is provided symmetrically in an inverted V shape with respect to the rotation direction. Pellets guided to both sides of the rotary blade cover are discharged through the gaps on both sides and guided to the product discharge chute.
As shown in the figure, the rotary blade cover 8 is usually shaped to follow the shape of the rotary blade, and has a curved shape. In order to guide the pellets captured from the central part of the width of the rotary blade toward both sides, at least one guide plate is symmetrical from the central part of the full width of the rotary blade 5 and is in the rotational direction of the rotary blade. On the other hand, it is preferable that it is attached inside the rotary blade cover in an inverted V shape. The left and right plates of the guide plates 9 and / or 91 are extended to both sides of the rotary blade cover and provided at least at both ends of the full width of the rotary blade, and the shape from the center of the rotary blade to both ends is provided. It is more preferable that the rotary blade cover is installed so that a linear shape or an arc shape is formed from the shape of the rotary blade cover and the inside of the arc is directed to the direction in which the pellet moves. Two or more guide plates are preferably provided (FIGS. 2 and 3 show a state in which two guide plates 9 and 91 are provided). By providing two or more guide plates, it becomes possible to capture the scattered pellets more completely.
[0016]
In addition, the guide plate 9 and / or 91 is preferably provided in a range in which the gap between the tip of the rotary blade and the guide plate is 2 mm to 10 mm. It is provided in a range where it does not come into contact, and is practically preferably attached to 2.5 mm to 6 mm. The rotary blade cover has a shape along the rotary blade, but as shown in FIG. 1, the rotary blade cover ceiling portion is slightly flat and the fixed portion direction and the tip portion direction have a curved shape inwardly curved. The gap between the tip of the rotary blade and the guide plate is wide on the ceiling side of the rotary blade cover and narrow on the tip side.
[0017]
In the present invention, the guide plate can be attached between the rotary blade cover portion E corresponding to the top of the rotary blade and the tip B of the rotary blade cover and parallel to the strand running surface. It is preferably provided between the intersection A with the rotary blade cover inner surface 81 of the tangential extension line in contact with the outer periphery of the rotary blade and the tip B of the rotary blade cover (the opposite side corresponding to the rotary blade cover fixing portion). Further, the positions of the V-shaped apexes C and C ′ of the guide plate having an inverted V-shape with respect to the rotation direction of the rotary blade are preferably 30 ° to 90 ° in elevation (normal angle) with respect to the strand running surface. More preferably, the elevation angle (regular angle) is in the range of 40 to 80 degrees, and the positions D and D ′ at both ends of the inverted V shape are at least the full width of the rotary blade. It is extended to both sides.
[0018]
Furthermore, even in the above-described configuration, a very small amount of pellets that have not been guided in the direction of the product pellet discharge chute 18 jumps out of the strand introduction port 11 and flows back between the strand take-up rollers 3 and 4 to receive the strands. Spatter from the chute 2 to the outside. In order to prevent the backflow pellets from being scattered outside, an opening 17 is provided in the running part 16 of the strand in the chute and discharged to the line-out chute 19 side.
The opening 17 on the running surface of the strand is preferably opened over the entire width of the running surface of the strand. The opening width of the opening 17 is not easily determined by the ability and size of the pelletizer, the size of the strand receiving chute and the size of the strand running portion, but is preferably 4 to 40 mm, more preferably 5 to 30 mm. It is. Moreover, it is preferable to provide the guide 20 in the opening part 17 so that a backflow pellet may enter an opening easily, and the guide 20 has a shape which inclines below the running part of a strand.
[0019]
Further, a very small amount of pellets that are not guided in the direction of the product pellet discharge chute 18 jump out from the gap between the upper portion of the strand introduction port 11 to the strand cutting portion 7 and the tip portion B of the rotary blade cover adjacent thereto. The air is scattered to the outside through the gap between the rotary blade cover 8 and the take-up roller cover 13. In order to prevent the pellets from splashing outside, the gap between the rotary blade cover and the take-up roller cover is closed to prevent the pellets from splashing outside (the portion about 40 mm from the tip) or roller cover. The pellet scattering prevention plate 12 is installed outside 13 (portion about 10 mm from the tip). It is preferable that the scattering prevention plate is installed outside the rotary blade cover from the viewpoint of work operation and the like.
[0020]
【Example】
Below, an example of the embodiment using the pelletizer of this invention is concretely demonstrated in detail by the manufacture example of a polycarbonate pellet.
[0021]
Example Polycarbonate resin material is used to extrude at a discharge rate of 129 kg / hr by an extruder, and an external scattering prevention plate 12 is installed with a pelletizer of the form shown in FIG. As shown in Fig. 5, the strand was cut using two guide plates 9, 91 and a pelletizer having an opening 17 on the strand running surface to obtain a pellet. The strand take-up speed was 18.5 m / min. The surface temperature of the strand was 76 ° C. The amount of scattered pellets in the upper part of the rotary blade cover was 0 g, and the amount of externally scattered pellets in the strand receiving chute was 0 g. The amount of pellets in the line-out generated during pellet production was hardly recognized.
The discharge rate is 154 kg / hr and the take-up speed is 28.2 m / min. In the case of the above, the amount of scattered pellets in the upper part of the rotary blade cover was 0 g, and the amount of external scattered pellets in the strand receiving chute was 0 g. The amount of pellets in the line-out generated during pellet production was hardly recognized.
[0022]
Comparative Example In the pelletizer used in the example, a polycarbonate resin material was used using a pelletizer similar to the example except that no guide plate and external scattering prevention plate were attached and no opening was provided in the strand running surface. Extrusion at a discharge rate of 129 kg / hr by an extruder as in the example, and the strand take-up speed was 18.5 m / min. Pellets were manufactured with. The surface temperature of the strand was 76 ° C. The amount of scattered pellets at the upper part of the rotary blade cover was 2.3 g / hr, the amount of scattered pellets at the strand receiving insertion port was 0.6 g / hr, and the amount of pellets generated during production was 50 g / hr. It was.
[0023]
【The invention's effect】
By using the pelletizer of the present invention, it is possible to prevent the pellets from scattering outside the pelletizer, improve the extrusion workability, prevent the pellets from being cut twice, and prevent the generation of chipped pellets, etc. can do. In addition, by using the pelletizer of the present invention, it is possible to guide the pellet product almost completely to the product discharge port, and the amount of outflow to the line-out side can be almost completely eliminated, thereby improving productivity. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional view showing an outline of an embodiment of a pelletizer according to the present invention.
FIG. 2 is a schematic top view of the appearance of the pelletizer of the present invention.
FIG. 3 is a partially enlarged view showing an inner surface of a rotary blade cover.
[Explanation of symbols]
1: guide roller, 2: strand receiving chute, 3: take-up upper roller, 4: take-down roller, 5: rotating blade, 6: fixed blade, 7: cutting part,
8: Rotary blade cover, 81: Rotary blade cover inner surface, 9, 91: Guide plate, 10: Baffle plate, 11: Strand introduction port, 12: External scattering prevention plate, 13: Take-off roller cover, 14: Fixed rotary blade cover 15: Rotary blade cover holding jig, 16: Strand running part, 17: Opening part, 18: Product pellet discharge chute, 19: Line-out pellet recovery chute, 20: Guide, 21: Front plate fixing pin 22: Pulley , Bearing housing, 23: gear, bearing housing A: intersection part of the tangent of the rotary blade parallel to the strand running surface and the inner surface of the rotary blade cover B: rotary blade cover tip C, C ': inverted V-shaped guide plate Vertex D, D ′: Positions of both ends of inverted V shape E: Location of rotating blade cover corresponding to zenith portion of rotating blade

Claims (5)

The strands sent strand receiving chute from the street take-off roll, in a pelletizer to cut between the rotary blade and the fixed blade, the pellets being scattered in the rotary blade cover, to guide the both sides of the rotating blade cover, the rotary blade At least one guide plate that is symmetrical in the direction of both sides of the rotary blade cover from the center of the width of the rotary blade and that is formed in an inverted V shape with respect to the rotational direction of the rotary blade is provided inside the rotary blade cover A pelletizer characterized by that.   The guide plate is attached to the inner side of the rotary blade cover from the intersection of the tangent line that contacts the outer periphery of the rotary blade parallel to the running surface of the strand and the inner surface of the rotary blade cover to the tip of the rotary blade cover. The pelletizer according to claim 1. The pelletizer according to claim 1 or 2 , wherein the guide plate is attached so that a gap between the tip of the rotary blade and the guide plate is 2 mm to 10 mm. The pelletizer according to any one of claims 1 to 3 , wherein an opening is provided on the lower surface of the strand running portion of the strand receiving chute. The pelletizer according to any one of claims 1 to 4 , wherein a plate for preventing scattering of pellets to the outside is provided in a gap between the outer side of the rotary blade cover and the outer side of the take-up roller cover.

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