JPS6251649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for adding or dehydrating a material fed into a cylinder in an extrusion process using an extruder, and an apparatus therefor.

[Prior art]

Conventionally, in the continuous extrusion process of the feed material fed through the hopper in an extruder, the technique of adding water or dehydrating the feed material in the cylinder is to provide a hole in a part of the inner wall of the cylinder and utilize this hole. BACKGROUND OF THE INVENTION Methods are known for supplying a predetermined amount of moisture to a feed material in a cylinder, or for removing moisture arising from a feed material under high pressure.

However, according to this technique, the pores mechanically formed in the inner wall of the cylinder are considerably large compared to the molecular level of the feed material, so the degree of hydration or dehydration of the feed material moved under pressure by the rotation of the screw is affected. Local unevenness tends to occur. Further, since it is necessary to control the degree of water addition or dehydration according to the pressure level near the hole, it is necessary to provide a pressure detection means including a pressure gauge, resulting in a problem that the structure is complicated accordingly.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and it is possible to evenly and uniformly add or dehydrate the feed material that is continuously moved by a screw, thereby improving the quality of extrusion molded products. To provide a method for adding water or dewatering a material fed into a cylinder in an extruder, and an apparatus therefor, which can simplify the configuration without the need to particularly provide a pressure detection means for adjusting the degree of water addition or dehydration. It is in.

[Structure of the invention]

The structure of the method for adding water or dehydrating the feed material in a cylinder in an extruder according to the present invention is such that in the process of kneading and extruding the feed material filled in the cylinder while moving it under pressure by the rotation of the screw, one part of the moving range is Water is added or dehydrated to part or all of the feed material through the many scattered fine pores of the screw material itself that is in contact with it, and the feed material in the cylinder of the extruder according to the present invention is hydrated or dehydrated. The dewatering device consists of a cylinder that is filled with the feed material, and a cylinder that is fitted into the cylinder.
The screw has a screw that rotates by a driving force to knead and extrude the supplied material while moving under pressure, and a water addition or dehydration pipe formed inside the screw, and the screw is made of a porous metal material having open cells. It consists of part or all of.

[Explanation of Examples]

Next, an apparatus for implementing the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a partial vertical cross-sectional view of a screw extruder to which the apparatus of the present invention is applied, and FIG.
It is a cross-sectional view of the main part of the figure. 1 is a cylinder of a screw extruder, and has a through hole 1a. 2
is a screw that is inserted into the through hole 1a of the cylinder 1 and rotated by a drive motor (not shown), and this screw is used to feed material (for example, plastic) fed in the direction of arrow A through a hopper (not shown). materials, food materials, etc.) to each fin 3
Knead while moving in the direction of arrow A while applying pressure using a, 4a, and 5a.

The screw 2 is generally composed of a front screw 3, an intermediate screw 4, a rear screw 5, a screw cap 6, and a screw drive shaft (hereinafter simply referred to as shaft) 7. The front screw 3 has boss portions 3c and 3d in its hollow portion 3b, which are fitted into the tip portions of the spline portion 7a on the tip side of the shaft 7 and the spline portion 7b in the middle, respectively. Here, since the number of protrusions on the spline parts 7a, 7b is missing so that the number of protrusions is smaller than the number of key grooves on the boss parts 3c, 3d, the hollow part 3e at the tip of the front screw 3 and the above-mentioned It is in communication with the hollow portion 3b. In addition, 8 is a screw tightening nut, 9
is a disc spring, and 10 is a washer.

The intermediate screw 4 also has a boss portion 4b inside the hollow space, and is fitted into the spline portion 7b of the shaft 7. The spline part 7b has missing teeth so that the number of protrusions is less than the number of keyways in the boss part 4b.
The intermediate screw 4 has a slightly smaller diameter than the front screw 3 and the rear screw 5, and is integrally made of a porous metal having open cells (for example, foamed metal (aluminum metal, etc.), sintered metal). ing. Therefore, the keyway of the boss portion 4b into which the protrusions of the spline portion 7b are not fitted and the outer peripheral portion of the intermediate screw 4 are in communication via the open cells of the material of the intermediate screw 4 itself.

In addition, the rear screw 5 also has a boss portion 5b in the hollow.
It has a spline portion 7b of the shaft 7 and is fitted into the spline portion 7b of the shaft 7. The number of protrusions on the spline portion 7c is equal to the boss portion 5.
There are fewer teeth than the number of keyways in b. Therefore, the hollow portion 3b and the base space B of the screw 2 are in communication via the key grooves of the boss portions 4b, 5b in which the protrusions of the spline portion 7b are not fitted.

The screw cap 6 is screwed onto the tip of the front screw 3, and like the intermediate screw 4, it is integrally made of porous metal having open cells.

The shaft 7 applies rotational force applied from its base by a drive motor (not shown) to each screw 3, 4, 5.
It has a hollow hole 7c. The base space B and the inside of the through hole 1a are kept watertight by a pressure rotary joint (not shown).

Next, the operation of the above implementation device will be explained.
First, pressurized water is supplied into the hollow hole 7c of the shaft 7 as shown by arrow a in the figure, and then sequentially by arrows b, c, d,
It flows and circulates like e, f, g, h. On the other hand, the screw 2 as a whole is rotating in a fixed direction, so that the material to be supplied is fed under pressure in the direction A in the figure, and gradually extruded toward the front of the screw cap 6 to be formed. In this state, the pressurized water press-fitted into the hollow hole 7c reaches the hollow portion 3e at the tip, and a part of it oozes out into the through hole 1a of the cylinder 1 through the open cells of the screw cap 6. Here, the open cells in the screw cap 6 function as fine tubes. In addition, the hollow part 3e at the tip
A part of the pressure water flowing through the keyway of the boss part 4b through the other hollow part 3b reaches the feed material in the through hole 1a with which the intermediate screw 4 comes into contact through the open cells of the intermediate screw 4. The open cells in the intermediate screw 4 also function as fine tubes.
In addition, depending on the material of the supplied material, screw 2
If it is necessary to add water to the entire body, the front screw 3 and the rear screw 5 may also be made of a porous metal material having open cells. Further, the screw cap 6, the front screw 3, the intermediate screw 4, and the rear screw 5 may be integrally formed of a porous metal material having open cells.

According to the above-mentioned implementation device, since the open cells function as a large number of fine tubes, water is uniformly added to the supplied material in contact with the screw cap 6 and the intermediate screw 4, thereby improving the quality of the extruded product. can be achieved. In addition, the hollow hole 7c
By simply changing the pressure on the screw 2
Since the amount of water discharged from the pump can be controlled, there is no need to provide any pressure detection means, and the configuration can be simplified accordingly.

Note that the above-mentioned implementation device uniformly adds water to the supplied material, but by pulling the hollow hole 7c with a suction pump, it is possible to uniformly dehydrate the supplied material. . In addition, not only the mere addition or dehydration of water, but also the addition of liquid additives, gas, etc. (hereinafter referred to as "hydration" in this application) can be performed evenly and uniformly.

Furthermore, when a heat medium is used as the fluid to be pressurized into the hollow hole 7c, the supply medium can be heated or cooled more directly and quickly.

Furthermore, the present invention can be carried out not only in a single-screw extruder but also in a multi-screw extruder.

〔Effect of the invention〕

The method according to the present invention is characterized in that water is added or dehydrated to the feed material through a large number of scattered fine pores that the material of the screw itself that is in contact with the feed material, and the apparatus according to the present invention Since the device is characterized in that a part or all of the device is made of porous metal having open cells, it has the following effects.

It is possible to uniformly add or dehydrate the supplied material over a certain range, thereby improving the quality of the extruded product.

By adding water to the heating medium, uniform heating or cooling over a certain range of the feed material can be rapidly achieved.

The control means for controlling the degree of water addition or dehydration can be simplified, and the device configuration can be simplified.

Since the material of the screw itself has micropores, there is no need to create micropores by special machining, and the number of manufacturing steps can be reduced accordingly.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal cross-sectional view of an extruder to which an apparatus for implementing the present invention is applied, and FIG. 2 is a cross-sectional view of the main part of FIG. 1. DESCRIPTION OF SYMBOLS 1... Cylinder of extruder, 1a... Through hole, 2... Screw of extruder, 3... Front screw, 3a,
4a, 5a...Fin, 3b, 3e...Hollow part, 3
c, 3d, 4b, 5b... Boss part, 4... Intermediate screw, 5... Rear screw, 6... Screw cap, 7... Screw drive shaft, 7a, 7b... Spline part, 7c... Hollow hole, 8... Screw tightening Nut, 9...Disc spring, 10...Washer.

Claims (1)

[Claims] 1. In the step of kneading and extruding the feed material filled into a cylinder while moving under pressure by the rotation of a screw, the feed material in a part or all of the movement range is A method for hydrating or dehydrating a material fed into a cylinder in an extruder, characterized in that hydration or dehydration is carried out through a large number of scattered fine pores that the material of the screw in contact with itself has. 2. A cylinder filled with the feed material, a screw fitted into the cylinder and rotated by a driving force to knead and extrude the feed material while moving under pressure, and a hydrated screw formed in the screw. or a dehydration pipe, and a part or all of the screw is made of a porous metal material having open cells.