JPH0611391B2 - Extrusion granulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to extrusion for producing pellets of synthetic resin molding material, ceramic molding material, various composite materials for synthetic resin molding, various additives, colorants and the like. The present invention relates to a granulating device.

(Prior Art) For example, an apparatus for producing a synthetic resin molding material has an appropriate space between a breaker plate (perforated metal plate) of an extruder and a discharge port, and is in a fluid state extruded from a breaker. It is designed so that the extruded material is extruded from each gate of the discharge port with a uniform pressure (Japanese Patent Publication No. 52-22779, etc.).

However, in recent years, various ceramics, including molded parts, composite materials, additives, or colorants, which are kneaded and granulated at a high concentration and a high filling rate with a synthetic resin as a binder, have been demanded. However, when granulating with such a material using the above-mentioned granulating apparatus, the pressure is not evenly transmitted to the discharge ports due to the low viscosity, and the extrusion speed at each discharge port becomes uneven. There was a problem that the length varied and granulation with stable viscosity became difficult.

As a result, the produced pellets have different apparent specific gravities, and it is necessary to obtain a stable weighing in advance to perform die molding using the pellets, and therefore, a weighing equipment must be attached.

The present invention solves the above problems, and an object thereof is to enable granulation with a stable viscosity with a simple structure.

(Technical Means) In the extrusion granulation apparatus, the above-mentioned object is to uniformly form perforations in the screw axial direction on the entire surface of the perforated plate, and to direct the extruded material toward the small-diameter squeezing hole provided in the central portion. A diaphragm wall having a narrowed cross-sectional shape for compression is installed downstream of the perforated plate,
In order to make the extrusion speed of the strand extruded from the projecting port constant, a plurality of outlet paths between the central hole and the discharge port, one end on the upstream side faces the throttle hole, and the other end on the downstream side communicates with the discharge port. Can be achieved by a configuration in which the aperture is provided radially around the aperture.

(Example) Hereinafter, description will be given with reference to the drawings.

In the figure, a 10-screw extruder is equipped with a screw 12 provided in a barrel 11 from a hopper 13 installed at a base end, and a breaker plate provided with an extruded material heated and melted by a heater 14 at a tip thereof. That is, it is extruded from the perforated plate 15. As shown in FIG. 2, the perforated plate 15 has a large number of perforations 16 in the axial direction of the screw which are evenly formed on the entire surface, and the barrel 11
It increases the back pressure inside and improves the kneading state.
It is attached to a holder 17 attached to the tip of 11.

A diaphragm wall 20 arranged subsequent to the perforated plate 15 has a diameter starting end 21 covering the outermost perforations 16 distributed in the perforated plate 15,
This is a steeply inclined taper surface which terminates at the entrance to the small-diameter throttle hole 22 opened in the center.

In the illustrated example, the diaphragm wall 20 and a surrounding wall 25 described later
It is formed on a tubular member 24 as shown in FIG. 4 and FIG. 4, and the tubular member 24 is held on the barrel 11 by the holding body 17.

The surrounding wall 25 has a start end 26 on the outlet side of the throttle hole 22 and a end 27 on the large-diameter tip. It has an inverted taper surface. A heater 28 is also provided outside this portion.

The inverted taper-shaped torpedo 30 in which the outer surface 34 is closely fitted to the surrounding wall 25 has a sharp end 31 located in or near the throttle hole 22 and a large-sized other end located on the discharge port side described later. 32 and 32 (FIGS. 5 and 6), the illustrated one is formed in an inverted conical shape with respect to the flow direction of the extruded material. On the outer surface of the torpedo 30, a plurality of recessed grooves 33 each having a substantially U-shaped cross section and extending from one end 31 to the other end 32 are formed radially from the one end 31.

The torpedo 30 is assembled by fitting the outer surface 34 so as to be in close contact with the surrounding wall 25, whereby the surrounding wall is formed.
A discharge path 35 surrounded by 25 and each concave groove 33 is formed, and a discharge port is formed.
The same number of 41 is continuously provided at the tip of each lead-out path 35. The number or total area of the discharge ports 41 is set to be smaller than the number or total area of the perforations 16 by a certain ratio.

A member 40 having a plurality of discharge ports 41 opened concentrically is bolted to the tubular member 24 while holding the torpedo 30 at a predetermined position (FIG. 1). 42 indicates the bolt. The torpedo 30 is also fastened to the center of the discharge port member 40 by another bolt. 43 indicates the bolt hole. The cutter 44 is attached via an arm 46 to a rotating shaft 45 that rotates about the screw axis. 47 is a similar arm,
Reference numeral 48 indicates a balancer attached to it, and 49 indicates an air duct for cooling the cut portion. The cut portion is covered by the cover 50, and the strand is discharged from the discharge port 51 at the lower end. A duct 52 connected to a blower can be attached to the cover 50 to cool the strand. Reference numeral 53 denotes a diffusion plate that makes the air blown out from the duct 52 uniform.

(Operation) In the extrusion granulating apparatus of the present invention configured as described above, when the extruded material charged into the hopper 13 is extruded from the perforations 16 of the perforated plate 15 in a fluid state, the central squeezing is performed by the squeezing wall 20. Hole
It is guided into a narrow space between the discharge port and the discharge port 41, and is guided from the throttle hole 22 to each of the plurality of discharge paths 35 toward the discharge port 41.

Therefore, the extruded material moves from the narrow space formed by the perforated plate 15 and the throttle wall 20 toward the central small-diameter throttle hole 22 and the discharge port 41 after exiting the perforations 16. Is discharged from the discharge port 41 without largely changing, and as a result, the pushing force is evenly distributed and transmitted to the plurality of discharge ports.

In this way, the extrusion speed of the strands extruded from the discharge port 41 is made constant, so that the cutting length by the cutter 44 is well aligned and stable granulation is performed. In addition, the lead-out path 35 and the concave groove 33 formed on the outer surface of the torpedo 30 and the torpedo 30
Since the torpedo 30 can be attached and detached by the surrounding wall 25 that fits with the above, the disassembly and cleaning of the concave groove 33, the squeeze port 22 and the like are facilitated.

(Effect) Therefore, according to the present invention, since the extruded material that is pressure-fed from the extruder to the discharge port is dispersed in the radial outlet passage 35 with the throttle hole 22 as the center, a uniform pressure transmission action is obtained. Even when granulation is performed using a low-viscosity extruded material, it is possible to produce pellets having a stable particle size and no variation in apparent specific gravity. Therefore, the pellet raw material obtained by the device of the present invention is excellent in meterability,
Contributes to stable quality of secondary products and high productivity. Particularly, according to the present invention, even a material having a low viscosity can be granulated at low cost, and the effect of increasing the added value by increasing the concentration of the raw material is obtained, which is extremely advantageous in practical use.

[Brief description of drawings]

The drawings show one embodiment of the extrusion granulating apparatus according to the present invention. Fig. 1 is a vertical sectional view of the whole, Fig. 2 is a rear view of a perforated plate, and Fig. 3 is a diaphragm wall, a diaphragm hole and an enclosure. A front view of a tubular member integrally having a wall, FIG. 4 is a sectional view of the same, FIG. 5 is a front view of a torpedo, FIG. 6 is a sectional view of the same, and FIG. 7 is a rear view of a member provided with a discharge port. , FIG. 8 is a front view of the cutter unit. 10 ... Extruder, 15 ... Perforated plate, 20 ... Throttle wall, 22 ... Throttle hole, 25 ... Enclosure wall, 30 ... Torpedo, 33 ... Concave groove, 34 ... Torpedo outer surface, 41 ... … Discharge port, 44 …… Cutter.

Claims (5)

[Claims] 1. An extruded material in a fluidized state by an extruder is extruded from a perforated plate attached to the barrel tip of the extruder, and the extruded strand is extruded from a discharge port provided at the tip of the perforated plate. In an extrusion granulator that cuts with a cutter placed outside the mouth, the holes in the screw axis direction are evenly formed on the entire surface of the perforated plate, and the extruded material is compressed toward the small diameter squeezing hole provided in the center. A throttling wall having a narrowed cross-sectional shape is installed downstream of the perforated plate in order to make the extrusion rate of the strand extruded from the discharge port constant, so that it is between the center hole and the discharge port, and the upstream side An extrusion granulating device, characterized in that a plurality of discharge passages, one end of which faces the squeezing hole and the other end of which on the downstream side communicates with the discharge port, are provided radially around the squeezing hole. 2. A member forming a discharge path has one end facing the throttle hole formed sharply and the other end on the discharge port side formed in a large shape, and the outer surface of the member facing from one end to the other end. And a reverse tapered torpedo provided with the same number and the same number of concave grooves and an outer wall of the torpedo that is closely fitted to the outer wall of the torpedo. The extrusion granulation apparatus according to claim 1, wherein the extrusion granulation apparatus is constituted by the surrounding wall. 3. The extrusion granulator according to claim 2, wherein the surrounding wall is provided integrally with the squeezing wall. 4. The extrusion granulation apparatus according to claim 2, wherein the torpedo is detachably provided on the surrounding wall. 5. The extrusion granulation apparatus according to claim 1, wherein the number or total area of the discharge ports is set smaller than the number or total area of perforations of the perforated plate.