JPS5820785B2 - inline screen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an in-line screw type plasticizing injection resin molding machine, and particularly relates to the shape of the screw.

Unlike conventional composite molding in which only resin is molded or a small amount of inorganic or organic matter is mixed with resin, ordinary screw light is used when molding a large amount of inorganic or organic matter mixed with resin. Conventional screw-type plasticizing equipment, which only has a
It is extremely difficult to mold uniform composites.

That is, rather than kneading inorganic or organic substances into resin, it is extremely difficult to knead resin into inorganic or organic substances.

When plasticizing a composite material by mixing a small amount of resin with a large amount of inorganic material using a normal screw, a molten film of resin is formed around the inorganic material, and the inorganic material is just engulfed in the molten resin film. Become.

With a normal screw, once this inorganic substance surrounded by a molten resin film is formed, it is difficult to completely disperse it to the end.

In order to completely disperse this, the inorganic substances that have been soaked in the molten resin film are crushed and mixed so that the inorganic substances inside come into contact with the new molten resin or semi-molten resin.
It is necessary to make movements that are kneaded.

However, in order to knead the molten or semi-molten resin into the inorganic substance and sufficiently disperse it, it is necessary to replace the air, etc. in the inorganic substance with the molten or semi-molten resin.

For this purpose, high pressures should not be applied to the minerals in this area.

That is, it is necessary to carry out the above-mentioned operation while smoothly degassing under low pressure.

This invention is intended to eliminate the above-mentioned drawbacks of the conventional method, and the surface of the screw has a special structure to improve the kneading effect.

In addition, in this invention, the head side where resin is injected is the front side, and the hopper side where the resin is supplied is the rear side.

Next, the present invention will be explained with reference to embodiments shown in the drawings.

In one embodiment shown in Figs. 1 to 4, 1 is a screw barrel, 2 is a screw rotatably and slidably provided in the screw barrel 1, 3 is a hopper for resin supply, 4 is an on-off valve, 5 is a check ring provided at the tip of the screw 2, and 6 is a vent hole.

The inside of the screw barrel 1 is generally divided into a resin supply zone a, a compression zone b1, and a metering zone C from the rear to the front.

7 is a screw flight provided continuously on the surface of the screw 2, and the surface of the screw 2 in the portion corresponding to the supply zone a to the compression zone b has a special shape.

That is, from the top rear end 8 of the screw flight 7 toward the bottom front end 9 of the next screw flight 7 on the rear side, there is a sloped part 10 without a rounded surface recessed at the top rear end of the screw flight 7, and this slope part. A flat portion 11 continuing from 10 is provided.

However, the flat portion 11 does not necessarily need to be provided.

Further, a plurality of shallow backflow grooves 13 extending from the upper part of the front end surface 12 of the screw flight 7 to the inclined part 10 are provided on the surface of the screw 2 at a certain distance apart.

The depth of the backflow groove 13 was set so that it did not reach the root of the screw flight 7 in the screw flight 7 section, and gradually became shallower toward the rear, reaching 0 at the rear end of the slope section 10. .

The cross-sectional shape of the backflow groove 13 may be arcuate as shown in FIG. 3, trapezoidal or other shapes.

The direction of the backflow groove 13 may be parallel to the axis of the screw 2. Normally, as shown in Fig. 2, the direction of the force input is θ≦ with respect to the axis.
Tilt by 35 degrees.

When using the conventional screw 2 having only the screw flight 7, the flow of the molten resin 14, inorganic substance 15, etc. becomes a relatively pure flow as shown by the arrows in FIGS. The mixing, kneading, and degassing of the inorganic substance 15 and the inorganic substance 15 are insufficient.

In particular, unmelted resin, resins, and inorganic substances that have not yet been sufficiently kneaded tend to accumulate immediately after the screw flight 7 and are difficult to knead.

On the other hand, in the apparatus of the present invention, as shown by the arrows in Fig. 7.8, the resin flows in a complicated manner.
Mixing and kneading of 4 and the inorganic component 15 and deaeration are performed well.

That is, by providing the inclined portion 10, unmelted resin, resin that has not yet been sufficiently kneaded, and inorganic substances remain in the rear part of the screw flight 7 in a small volume, so that they are easily mixed.

Also, by providing the backflow groove 13, the resin, etc. in the front part of the screw flight 7 can pass through the backflow groove 13 and move backward, or come out from the middle of the backflow groove 13 and move in the circumferential direction. This ensures sufficient mixing and kneading.

The angle of inclination of the surface of the inclined portion 10 with respect to the axis of the screw 2 was made to be the same at any position in the embodiment shown in FIGS. The angle of inclination of the surface of the inclined portion 10 may be gradually reduced toward the front to gradually increase the compression ratio.

Further, in the above embodiment, the depth and shape of the backflow groove 13 were made the same at all positions, but this is also possible by making the depth of the backflow groove 13 gradually shallower as it goes forward of the screw 2. The pressure in the space between the barrel 1 and the screw 2 may be gradually increased, or conversely, the depth of the backflow groove 13 may be gradually increased toward the front of the screw 2, thereby increasing the pressure in the space between the barrel 1 and the screw 2. The pressure in the space between the two may be gradually reduced.

Further, the pitch of the screw flights 7 may be kept constant and the width of the screw flights 7 may be gradually increased toward the front of the screw 2 to increase the compression ratio. The compression ratio may be reduced by gradually narrowing the width of the screw flight 7 toward the front.

In addition, when the direction of the backflow groove 13 is inclined by θ with respect to the axis, the front part of the backflow groove 13 may be inclined in the direction opposite to the rotational direction of the screw 2, as shown in FIG. Conversely, it may be tilted in the same direction as the rotation direction.

In the former case, the feeding capacity does not decrease even if the pressure is maintained at a low pressure.

In the latter case, the feeding capacity is slightly reduced, but the kneading effect is further improved.

In the embodiment shown in FIG. 1, only the screw flight 7 was provided on the surface of the screw 2 in front of the portion where the inclined portion 10 and the backflow groove 13 were provided, but as shown in FIG. Furthermore, a cylindrical convex portion 17 may be provided on a part of the screw 2 so as to form a narrow parallel gap 16 between the screw barrel 1 and the screw 2 in front of the inclined portion 10.

As shown in FIG. 1, the position of the vent hole 6 is
In this way, in this invention, the inclined part 10 is provided on the screw surface following the screw flight 7. Therefore, strong shear can be applied by the screw flight part 7 and the inclined part 10, and the inorganic and organic substances can be easily kneaded into the resin and degassed by the strong shear under low pressure.

In particular, this inclined part 10 is made into an inclined part without a concave rounded surface at the rear end of the top of the screw flight, so that a strong wedge effect due to the taper increases the pressing force of the solid bed, which is an unmolten solid, against the inner surface of the barrel. increases, and a strong kneading effect can be imparted to the melted film after melting.

In addition, since the solid bed is easily softened by the heat supplied from the barrel and the top of the flight, it is not necessary to apply excessive mechanical energy to the entire solid bed, which prevents the destruction of inorganic substances and secondary agglomeration. Can be done.

Furthermore, since the backflow groove is provided, the pressure in the entire screw flight section can be maintained at a low pressure.

therefore. Agglomeration of inorganic and organic substances in fine particles due to high-pressure plasticization can be avoided, and degassing is easy.

In addition, the shallow backflow grooves provided in the slope section cause the solid bed to be compressed, relaxed, and destroyed, making it easier to release volatile matter.

Furthermore, since the molten or semi-molten composite mixture flowing back through the backflow groove and the unmelted composite in the slope section are constantly brought into new contact and mixed, combined with the strong shearing action of the slope section, an extremely good A crosstalk condition is obtained.

The melt that has flowed back from the top of the screw flight through the shallow backflow groove comes into contact with the fractured surface of the solid bed, causing a heating effect on the solid bed, which prevents the solid bed from softening and causing unnecessary mechanical stress. You can save energy.

Therefore, damage and secondary aggregation of inorganic substances can be avoided.

In addition, in the shallow backflow groove at the top of the screw flight,
A large kneading effect can be obtained in the melt itself due to the relative sliding between the screw and barrel.

Note that even if a backflow groove is provided, the screw flight itself is continuous, so the feeding capacity will not be reduced.

Therefore, it has a sufficient kneading effect and a sufficient ability to feed the composite.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Fig. 2 is a partially enlarged view of Fig. 1, Fig. 3 is a sectional view taken along the line ■-■ of Fig. FIG. 5 is a longitudinal sectional view showing the state of resin flow in the conventional device; FIG.
The figure is a sectional view taken along the line VI-Vl of FIG. 5, FIG. 7 is a longitudinal sectional view showing the state of resin flow in this invention, and FIG.
FIG. 9 is a partial vertical sectional view showing another embodiment of the present invention. 1...Screw barrel, 2...Screw, 7...Screw flight, 10...
- Inclined part, 11...Flat part, 13...
Backflow groove, 14...Resin, 15...Inorganic substance,
16...Parallel gap.

Claims (1)

[Claims] 1. A sloped part without a concave rounded surface is provided at the rear end of the top of the screw flight from the rear end of the top of the screw flight toward the front end of the bottom of the next screw flight on the rear side. A plurality of shallow backflow grooves extending to the rear end of the inclined part at the bottom front end of the next screw flight are provided on the screw surface at fixed intervals in the circumferential direction, and the depth of the backflow grooves is as follows: An in-line screw type resin molding machine equipped with a screw having a depth that does not reach the root of the upper screw flight near the upper part of the front end surface of the screw flight, and gradually becomes shallower toward the rear end of the inclined part.