JPH0299305A - Biaxial kneader - Google Patents

Abstract

PURPOSE:To enhance workability by providing a barrel valve driven forward and backward in the inner bore crossing direction supported with a guide block on the barrel side in a manner of expanding, contracting and adjusting a space section area between a valve ring and an inner bore of the valve and boring a heating and cooling opening on the guide block. CONSTITUTION:When a handle 13 is installed on a nut 11 and pivoted, a screw shaft 14 is moved forward and backward by the screw action, and a barrel valve 6 is moved forward and backward along an opening 9 encircled with guide blocks 7 and guide plates 8 on both sides. As a result, the section area of a ring space section 5 is expanded and contracted by an opening 6a of a barrel valve 6 to adjust the filling ration of resin. When filling ratio is increased, moving resistance of resin is decreased in a screw section to weaken kneading and lower the temperature of resin, while kneading is made stronger by increas ing filling ratio in the kneading section of a paddle or the like. After adjustment, the guide blocks 7 and surrounding sections are cooled by switching openings 7b of the guide blocks 7 over to solidify the resin coming into the space and prevent the resin from leaking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-screw kneader for kneading materials such as resins by rotating a pair of screw shafts that are close to each other and parallel to each other.

[Conventional technology]

Kneaders that knead resin, etc. supplied into a barrel with a screw shaft rotating inside the barrel are classified into single-screw kneaders and twin-screw kneaders depending on the number of screw shafts, and among these, two-screw kneaders are It is widely used for kneading resins, etc. because it is easy to obtain an ideal kneading degree.

This twin-screw kneading machine is equipped with a plurality of barrels whose inner holes are formed in the shape of glasses and which are flanged in the axial direction of the inner holes. The screw shafts are rotatably supported close to each other and parallel to each other, and are driven to rotate in the same direction or in different directions by motors.

A metering feeder for feeding materials such as resin into the barrel 1 is attached to the front part of the barrel 1, and the extrusion nozzle of the barrel valve is generally connected to a granulating device.

With this structure, when the screw shaft is rotated while the resin is fed into the inner hole of the barrel with a constant feeder and heated, the molten resin is not kneaded by the rotating screw shaft and is mixed inside the barrel. is sent to the tip, extruded from the nozzle, extruded and cut by the granulation device, and then
Upon cooling, it solidifies and becomes a pellet.

When kneading resin using such a two-screw kneader, unlike a single-screw kneader, the rotation speed of the screw shaft is not proportional to the amount of resin discharged, but the amount of resin supplied by the quantitative feeder is Therefore, in order to obtain a kneaded resin with optimal physical properties, the amount of resin input, resin temperature, rotation speed of the screw shaft, screw configuration, degree of resin filling in the barrel, resin It is necessary to adjust pressure, etc., and the more of these factors can be freely selected and adjusted during operation, the wider the effects can be expected.

Therefore, conventionally, the screw shaft is formed by a central shaft and a plurality of segment screws mounted in parallel on this central shaft, and segment screws with different screw pitches or with special paddles are used as segment screws. They are prepared and exchanged for use. As a result, the feeding speed of the resin in the barrel is adjusted, and the resin is sent back and forth to adjust the filling degree of the resin.

[Problem to be solved by the invention]

However, adjusting the filling level in such conventional twin-screw kneading machines not only does not allow for sufficient adjustment, but also requires replacing the segment screws each time the adjustment is made, which is troublesome and takes a long time. there were. It has also been proposed to install a sliding gate at the resin outlet of the barrel and open and close it to adjust the amount of resin discharged, but in this case, a large thrust force will act on the screw shaft, so it is recommended to install a thrust bearing for this purpose. However, since the two shafts are close to each other, there is a problem in that their size is restricted, and there is also a problem in that resin enters the sliding part of the gate and prevents it from opening and closing.

[Means to solve the problem]

In order to solve such a problem, the present invention provides a valve ring with a smaller diameter than this, which is attached to the central axis of the screw shaft and interposed between adjacent segment screws at the middle part of the screw shaft. Barrel pulp is supported by a guide block on the barrel side and is provided with barrel pulp that is driven forward and backward in the direction across the inner hole so as to expand and contract the cross-sectional area of the space between the inner hole of the valve and the inner hole of the valve. Heating and cooling holes connected to a source and a cooling source were drilled.

[For production]

When resin is fed into the barrel with a quantitative feeder and the screw shaft is rotated, the resin is melted, kneaded, sent to the tip of the barrel, and extruded from the nozzle.

When the barrel pulp is advanced or retreated, the cross-sectional area of the space between the valve ring and the barrel inner hole expands or contracts, and by changing the amount of squeezing, the degree of resin filling is adjusted, making the kneading stronger or weaker. When the barrel pulp is cooled, the resin that has entered the gap between the sliding part and the guide block solidifies, and leakage of the resin from this gap is prevented. Furthermore, when cooling is stopped from this state and the barrel pulp is heated, the resin in the gap melts, making it possible to adjust the advance and retreat of the barrel pulp.

〔Example〕

1 to 7 show an embodiment of the twin-screw kneading machine according to the present invention, FIG. 1 is a longitudinal cross-sectional view of the vicinity of the center of the barrel, and FIG. An enlarged vertical sectional view, FIG. 3 is a partially cutaway front view of the barrel pulp and valve ring, FIG. 4 is a plan view, FIG. 5 is a front view of the guide block, and FIG. 6 is a front view of the barrel pulp. 7th
In Figure 0, which is also a vertical cross-sectional view, I denotes a plurality of barrels having a rectangular outer shape and having horizontally long rectangular flanges la at both ends, and the flanges la are joined to each other and extended. Near the front end of its entire length,
A resin supply port 1b to which a quantitative feeder (not shown) is attached is open. Each barrel 1 is provided with an inner hole 1c having a spectacle-shaped cross section, and within the inner hole 1c, a pair of screw shafts 2 extending over the entire length of the barrel 1 are close to each other.

They are rotatably supported in parallel. This screw shaft 2
A central shaft 2a that passes through the center of the inner hole 1c and is rotatably supported, and reference numerals 2b and 2c in the figure.

As shown by 2d, it is formed by segment screws that are divided into a plurality of pieces and are mounted in parallel on the central shaft 2a,
Each segment screw 2b, 2c.

2d is selected from screws with different screw pitches, etc., and is pivotally mounted. The two rows of screw shafts 2 are rotationally driven by a motor (not shown) via a transmission, and in this embodiment, they rotate in the same direction. In this embodiment, the tip of the barrel l is connected to a granulating device (not shown). With this configuration, the resin is supplied from the supply port 1b into the barrel l by the quantitative feeder, and when the screw shaft 2 rotates, the resin is kneaded and sent inside the barrel 1 to the tip, and then from the nozzle. Extruded to granulation equipment.

Between 797218 of barrels 1 adjacent to each other at locations corresponding to intermediate joints of screw shafts 2, a filling degree adjusting device, generally designated by reference numeral 3, is interposed. That is,
A valve ring 4 formed in an annular shape with a smaller diameter is mounted and interposed between adjacent segment screws 2b and 2c in the middle part of the barrel 1, and the outer circumferential surface of the valve ring 4 and the inner circumference of the barrel l are interposed. An annular space portion 5 is formed between the portion 1c and the portion 1c. Reference numeral 6 denotes a barrel valve which is formed into an eagle-square plate shape and is divided into upper and lower parts from the center.
This is provided with a hole 6a formed in the shape of a spectacle similar to the inner hole 1c of the barrel l and having a smaller diameter than the inner hole 1c. has been done. Between the barrel valve 6 and each flange la on both sides, an inner hole 1c is formed in a plate shape having the same shape as the flange 1a.
A guide block 7 having a hole 7a of the same size as that of the barrel valve is interposed in each case, and the guide block 7 is integrated with the flange 1a by bolts together with a pair of guide plates 8 formed in a rectangular shape. 6 is fitted into a hole 9 having a rectangular cross section formed by a pair of guide blocks 7 and a pair of guide plates 8 so as to be freely movable in a direction transverse to the inner hole 1c. The openings at both the upper and lower ends of the hole 9 are closed with plates 10 formed in the form of strips and secured with bolts, and in these upper and lower plates 10, a cylindrical nut 11 with a thread cut in the inner hole is installed to hold the bearing. It is rotatably supported via 12,
A handle 13 is detachably attached to each nut ti. Reference numeral 14 denotes a screw shaft whose threaded portion is screwed into the screw hole of the nut 11, and the flange 15 at one end thereof is bolted to the barrel valve 6. By rotating the nut 11 with the handle 13, the screw shaft can be screwed. The screw shaft 14 is moved forward and backward by the action, and the barrel valve 6 is moved forward and backward, so that the cross-sectional area of the space 5 is expanded or contracted.

Further, each guide block 7 is provided with a heating/cooling hole 7b connected to a heating source and a cooling source, the end of which is closed with a stopper 16. By switching a valve (not shown), the guide block 7 is configured to be heated or cooled.

The operation of the two-screw kneader configured as above will be explained.

When resin is supplied into the barrel 1 from the supply port 1b by the quantitative feeder and the motor is started, the screw shaft 2 rotates via the transmission, and the resin in the barrel 1 is melted and kneaded and sent to the tip of the barrel l. sent towards. This resin is extruded from the nozzle at the tip of the barrel l to the resin road of the granulator, extruded in a molten state from multiple nozzles, cut into granules by a rotating cutter, and then solidified by cooling and recovered. be done.

When adjusting the degree of resin filling in the barrel l, the handle 13 is attached to the nut 11 and rotated repeatedly, and the threaded shaft 14 advances and retreats due to the screw action, and the barrel valve 6
moves forward and backward along a hole 9 surrounded by guide blocks 7 on both sides and guide plates 8 on both sides. As a result, barrel valve 6
Since the cross-sectional area of the annular space 5 is expanded or contracted by the holes 6a, the degree of filling of the resin is adjusted. When the degree of filling is increased, the resistance to the movement of the resin decreases in the screw portion, making the kneading weaker and the temperature of the resin lowers.In addition, when the degree of filling is increased in the kneading portion such as the paddle, the kneading becomes stronger.

After adjustment, there is a risk of resin leaking from the gaps between the sliding part of the barrel pulp 6, the guide block 7, and the guide plate 8. Therefore, if the hole 7b of the guide block 7 is switched to the cooling source side, the guide block 7 and its The surrounding area is cooled and the resin that has entered the gap solidifies, making it possible to prevent the resin from leaking through the gap. When adjusting the filling level again, when the hole 7b is switched to the heat source side, the resin solidified in the gap is melted, allowing the barrel valve 6 to move forward and backward without interfering with the adjustment operation.

Although the present embodiment shows an example in which the center shaft 2a of the screw shaft 2 is formed into a round bar shape, if a spline groove-like groove is provided on the outer periphery of the center shaft 2a, insertion of the segment screw 2b, etc. is facilitated.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in a two-screw kneading machine, a pulp ring with a smaller diameter than the segment screws is attached between adjacent segment screws in the middle part of the screw shaft. A barrel valve is supported by a guide block on the barrel side and is provided with a barrel valve that is driven forward and backward in a direction across the inner hole so as to adjust the cross-sectional area of the space between the valve ring and the inner hole of the pulp. By drilling heating and cooling holes connected to external heating and cooling sources in the guide block, adjustments such as the degree of filling of resin in the barrel can be made by turning the handle while checking the degree of kneading while the machine is running. It is possible to carry out the process only by rotary operation or by remote operation, which greatly improves work efficiency and enables appropriate adjustment, thereby improving kneading performance. In addition, since the area around the sliding part for adjustment can be cooled and the resin can be solidified, resin leakage can be prevented and
During adjustment, the area around the sliding part can be heated to melt the resin, so the adjustment operation is not hindered.

[Brief explanation of drawings]

1 to 7 show an embodiment of the twin-screw kneading machine according to the present invention, the first is a longitudinal sectional view near the center of the barrel, and the second is a longitudinal cross-sectional view of the vicinity of the barrel center.
The figure is an enlarged vertical cross-sectional view of the vicinity of the outer circumference of the pulp ring in Figure 1, Figure 3 is a partially cutaway front view of the barrel valve and valve ring, Figure 4 is a plan view of the same, and Figure 5 is a front view of the guide block. FIG. 6 is a front view of the barrel valve, and FIG. 7 is a longitudinal cross-sectional view. 1...Barrel, IC...Inner hole, 2...Screw shaft, 2a...Center shaft, 2b, 2c, 2d...
・Segment screw, 3... Filling level adjustment device, 4
... Barrel ring, 5 ... Space part, 6 ...
Valve ring, 7...Guide block, 7b...
・Heating, cooling hole, 11...nut, 14...screw shaft. Figure 1 Patent applicant Ube Industries Co., Ltd.

Claims (1)

[Claims] In a two-screw kneading machine equipped with a pair of screw shafts, each consisting of a central shaft and a plurality of segment screws mounted in parallel on the central shaft, the segment screws are fitted into inner holes of a barrel to rotate, A valve ring with a smaller diameter than this is inserted between adjacent segment screws at the middle part of the screw shaft, and is attached to the central shaft, and the cross-sectional area of the space between the valve ring and the inner hole of the valve is reduced. A barrel valve that is driven forward and backward in a direction across the inner hole to adjust expansion and contraction is supported by a guide block on the barrel side, and this guide block has heating and cooling holes connected to external heating and cooling sources. A two-shaft kneading machine characterized by having a perforation.