JP2601645B2 - Kneading control device for continuous kneading machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kneading control device for a continuous kneader for continuously plasticizing and melting plastic materials such as plastics and rubber and kneading additives and fillers.

[0002]

2. Description of the Related Art In a continuous kneader for plastics, for example, two rotors having kneading blades are arranged in parallel in a chamber having a supply port and a discharge port, and a kneading material additive supplied from a supply port and The filler and the like are kneaded by the rotor and plasticized and melted, and are discharged from the discharge port.

In order to improve the quality of the kneaded product, various kneading control devices for controlling the kneading degree, pressure or temperature during the kneading operation have been developed. As a prior art of the kneading control device, there is a device disclosed in Japanese Patent Publication No. 56-3091. In the first technique, a gear pump for feeding the kneading material to a post-processing device is directly connected to a downstream side of a discharge port of a chamber, and the rotational speed of the gear pump is controlled by a variable motor to reduce the pressure at the inlet of the gear pump. By controlling, the kneading degree is adjusted by changing the filling degree of the material in the chamber.

The first technique has a sufficient effect that can be used for kneading a resin having a low viscosity. However, the kneading of a high-viscosity resin requires a small pushing force of a rotor, so that the efficiency of biting into teeth of a gear pump is reduced. Of the resin, the hunting phenomenon of the pressure may occur, and the melting start point of the resin may fluctuate, resulting in unstable operation. As an improvement to solve such a problem of the first technique, a second technique of controlling the kneading degree by adjusting a material supply amount to a supply port and an axial flow of the material near the discharge port are disclosed. There is a third technique (see Japanese Patent Application Laid-Open No. 58-183210) in which a pressure and a temperature are controlled by providing a fixed dam for shielding.

[0005] The second technique has a problem that the adverse effect on the kneading action is small, but the effect is small and the control response is poor. The third technique is effective for a resin having a certain viscosity. In addition, there is a problem that it is difficult to cope with a difference in the viscosity of the resin. The fourth technique (JP-A-60-107999 and the drawings) shown in FIG. 5 solves the problem by organically combining the advantages of the first to third techniques.

According to the fourth technique, a gear pump 7 is disposed downstream of a discharge port 3 of a chamber 4, a feed device 6 is disposed above a supply port 2, and a movable dam 8 'is provided near the discharge port 3. The gear pump 7 detects the pressure at the inlet with the sensor P1C, controls the variable motor M4 within a range in which the gear pump 7 can be operated stably, always keeps the feed condition by the feed device 6 constant, Sensor T
1C, the number of rotations of the motor M2 for the rotor, the feed conditions, and the like are input to the dam controller 14, and the area of the shear in the chamber 4, the degree of filling, and the like are changed by the movable dam 8 '. Kneading is performed stably and effectively.

On the other hand, although the kneading degree adjusting method is different, a technique for adjusting the kneading degree and enabling highly efficient kneading with a gear pump is disclosed in Japanese Patent Application Laid-Open No. 61-2335.
No. 08 (fifth technology). This fifth
The technology includes an axially movable cylinder having a supply port and a discharge port, two cantilevered screws having kneading blades and arranged in parallel in the cylinder, and a cylinder supply port. And a slot formed between the cylinder and the screw and disposed between the discharge port, and a gear pump disposed downstream of the discharge port opened in the cylinder axis direction,
The slot is slot adjusted by adjusting the position of the cylinder in the axial direction with respect to the screw,
The screw is formed with a tip screw having a smaller diameter than the kneading blade from the slot to just before the discharge port.

[0008]

However, also in the fourth technique, the movable dam 8 'faces the kneading wing portion B which is long in the axial direction of the rotor 5 but has a small sectional area.
The amount of change in shielding of the material is small, and the temperature or pressure of the resin at the discharge port 3 is hardly changed. On the contrary, the pressure or temperature of the material when passing through the movable dam 8 ′ changes under the influence of the control of the gear pump 7. Control can be difficult or inaccurate. Further, since the rotor 5 itself does not have an extruding ability near the discharge port 3, it is difficult to eliminate poor biting of the high-viscosity resin into the gear pump 7.

In the fifth technique, the tip screw portion is effective for forcibly feeding the kneading material to the gear pump to improve the bite in the gear pump. However, if a slot portion is formed in the screw, the kneading blade is inevitably formed. When the diameter becomes smaller than that of the section and the cylinder moves in the axial direction, the distance between the tip screw section and the gear pump changes, and the length of the tip screw section overlapping the cylinder and the length from the tip of the tip screw section to the gear pump are changed. Variations in the magnitude will vary the suction pressure of the gear pump. In addition, in order to move the cylinder freely, not only the cylinder but also the gear pump and a post-processing device downstream thereof need to be movable, which occupies an extremely large cost and requires high precision. Fine kneading adjustment is difficult.

According to the present invention, the rotor is axially fixed with respect to the cylinder, a circular section and a feed blade are formed downstream of the kneading blade of the rotor, and the movable dam is opposed to the movable dam substantially along the circular section. An edge is formed so that the material passage area can be greatly changed, and the material is forcibly fed to the gear pump at the feed wing so that the control by the gear pump does not affect the control by the movable dam and the cost is low. An object of the present invention is to provide a kneading control device for a continuous kneader that can be manufactured.

[0011]

The concrete structure for solving the problems of the present invention is as follows: a chamber 4 having a supply port 2 and a discharge port 3; Two rotors 5 arranged and fixed in the axial direction with respect to the chamber 4, and a movable member provided between the supply port 2 and the discharge port 3 of the chamber 4 so that the position in the radial direction can be adjusted with respect to the rotor 5. The movable dam 8 includes a dam 8 and a gear pump 7 disposed downstream of the discharge port 3. The movable dam 8 faces and substantially follows a circular section C formed downstream of the kneading blade B of the rotor 5. The rotor 5 has a feed wing portion D extending from the downstream side of the circular section C to the discharge port 3 for forcibly pushing the kneading material to the gear pump 7. is there.

[0012]

The material supplied from the supply port 2 by the feed device 6 is sent to the kneading blade portion B by the screw portions A of the two rotors 5 which are stationary relative to each other in the axial direction in the chamber 4, and the kneading and shearing operations are performed. It is plasticized and melted. The plasticized and melted material has a circular section C on the downstream side of the kneading blade section B.
, And is strongly pushed out to the discharge port 3 by the feed blade portion D, and discharged to the post-processing device by the gear pump 7 at a required pressure.

The movable dam 8 has an opposing edge 12 substantially along the outer peripheral surface 11 of the circular section C. By adjusting the radial position of the movable dam 8, the area of the circular section C and the material passing area therebetween can be substantially reduced. The temperature and pressure of the material can be controlled by changing the material passage area from zero to the fully open state of the chamber 4. Since the material is forcibly pushed into the gear pump 7 by the feed wing portion D having substantially the same diameter as the kneading wing portion B, no biting failure occurs, the capacity is not suppressed, and The control of the material supply to the processing apparatus is interrupted by the feed wing D, and does not affect the control by the movable dam 8.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4, in a continuous kneader 1, two rotors 5 are disposed in parallel in a chamber 4 having a supply port 2 and a discharge port 3, and a feed device 6 is provided above the supply port 2 and a discharge port is provided. 3, a gear pump 7 is arranged below, and a movable dam 8 is arranged in the middle of the supply port 2 and the discharge port 3 respectively.

The feed device 6 is of a type in which a feed screw 10 is driven by a variable motor M1, and supplies a kneading material such as plastic and rubber, an additive, a filler and the like to the supply port 2 by a required amount. The two rotors 5 have the same shape and are adjacent to each other in a meshing state, are synchronously rotated by a motor M2, are axially fixed with respect to the chamber 4, and are downstream from the screw portion A located on the supply port 2 side. A kneading wing portion B, a circular cross-section portion C and a feed wing portion D are sequentially formed on the side.

The screw section A and the kneading blade section B are shown in FIG.
4 has a substantially triangular cross section, and kneading while feeding the material,
The kneading operation is substantially completed when plasticizing and melting by the pressure and heat and passing through the circular section C, and the feed wing section D mainly only pushes the molten material to the discharge port 3. As shown in FIG. 1, the feed wing portion D has substantially the same shape as the screw portion A and has substantially the same diameter as the kneading wing portion B. The feed wing portion D extends from the downstream side of the circular section C to the discharge port 3. ing. In this embodiment,
Then, as shown in FIG. 1, the chamber 4 was opened on the lower surface side.
Since the gear pump 7 is connected to the discharge port 3,
Further downstream of the wing portion D (the most downstream portion of the rotor 5),
The parallel wing E for dropping the resin into the outlet 3 is shaped
Has been established.

The chamber 4 facing the feed wing portion D
A vent 9 is formed at the portion (1), so that volatiles generated from the material during kneading can be discharged. This vent 9 prevents feed obstruction caused by the backflow of volatiles to the supply port 2. The movable dam 8 is provided in a pair of upper and lower portions facing the circular section C. Circular section C
Is slightly smaller than the inner diameter of the chamber 4,
Each of the upper and lower movable dams 8 has an opposing edge 12 substantially along the outer peripheral surface 11.

That is, the opposing edge 12 is formed by arranging circular arc surfaces having the same or slightly larger curvature as the outer peripheral surface 11 side by side, and can be adjusted in the radial direction with respect to the circular section C by the motor M3. I have. The motor M3 of the vertically movable dam 8 is constituted by one or two tuned motors so that the vertically movable dam 8 can be moved in the opposite direction by the same amount via a rack and pinion mechanism or a screw jack mechanism. . Further, the vertically movable dam 8 may be driven by a hydraulic cylinder.

The upper and lower movable dams 8 can change the material passage area from substantially zero to a fully open state in the chamber 4 by adjusting the far and near positions with respect to the circular section C.
By reducing the area, the flow resistance of the material is increased,
Temperature and pressure are increased. TIC and PIC are a temperature sensor and a pressure sensor which measure the temperature and the pressure of the passing material, respectively, and control the motor M3. Therefore, the temperature or pressure of the material is measured, and if the required kneading degree is not attained, the motor M3 is operated, and the movable dam 8 adjusts the gate between the movable dam 8 and the circular section C to control the kneading degree (melting). Adjust the starting point).

The gear pump 7 has a motor M as in the prior art.
4 and is driven by a pressure sensor P
The measurement is performed by an IC, and the motor M4 is controlled to adjust the supply amount of the kneading material to the post-processing device. The gear pump 7 is particularly useful for a high-viscosity material that is difficult to supply to a post-processing apparatus by only sending it out by the feed wing D, and the pressure change due to the control causes the material to be forcibly fed by the feed wing D. Therefore, the control by the movable dam 8 and the control by the gear pump 7 are independent from each other during the kneading operation.

[0021]

According to the present invention described in detail above, since the movable dam 8 has the opposing line 12 which is opposed to and substantially along the circular section C of the rotor 5, the movable dam 8 is located between the rotor 5 and the chamber 4. It is possible to change the material passage area from substantially zero to full open, to increase the range of controlling the kneading degree by changing the flow resistance of the material, and to enable effective kneading control.
You. Further, since the rotor 5 is provided with the feed wing portion D for forcibly pushing the kneaded material to the discharge port 3, it is possible to reduce a material biting defect in the gear pump 7, and
Gear pump 7 to supply the material to the after-treatment device smoothly
Does not affect the kneading control by the movable dam 8, the kneading control can be performed accurately and easily, and stable operation can be performed even when kneading high-viscosity materials. .

The suction pressure of the gear pump 7 can be varied by providing a movable dam 8 whose position in the radial direction can be adjusted as compared with the prior art in which the chamber 4 is moved in the axial direction to adjust the slot. In addition, the kneading degree can be adjusted without any trouble, and the rotor 5 is fixed in the axial direction with respect to the chamber 4 so that the chamber 4 and the gear pump 7 are not moved. High accuracy is realized.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is an explanatory diagram showing a fourth conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Continuous kneader 2 Supply port 3 Discharge port 4 Chamber 5 Rotor 6 Feed device 7 Gear pump 8 Movable dam 12 Opposite edge A Screw part B Kneading wing part C Round section D Feed wing part

Claims (1)

(57) [Claims] 1. A chamber (4) having a supply port (2) and a discharge port (3), and a kneading wing (B) arranged parallel to and inside the chamber (4) with a kneading blade (B). On the other hand, between the two rotors (5) fixed in the axial direction and the supply port (2) and the discharge port (3) of the chamber (4), the radial distance position of the rotor (5) can be adjusted freely. It has a movable dam (8) provided and a gear pump (7) arranged downstream of the discharge port (3), and the movable dam (8) is a kneading blade (B) of a rotor (5). The rotor (5) has an opposing edge (12) opposed to and substantially along the circular section (C) formed on the downstream side of the rotor. The rotor (5) has a circular section for forcibly pushing the kneading material to the gear pump (7). discharging from the downstream side of the (C)
A kneading control device for a continuous kneader, wherein a feed wing portion (D) extending to an outlet (3) is formed.