JPS6017303Y2 - extruder - Google Patents

Description

[Detailed description of the invention] This invention provides a screw-like kneading roller with one or more spiral grooves on the outer periphery in the middle of a rotating screw, and a bypass groove is provided in the kneading roller, and the rotation of the kneading roller allows the resin raw material to be The present invention relates to an extruder for kneading.

This type of extruder currently in use has a number of spiral grooves arranged in parallel on the outer peripheral surface of the kneading roller. However, the spiral grooves are continuous over the entire length, creating a large resistance to the flow of the resin raw material, making it impossible to reduce the pressure. If the rotation speed is not increased or if a resin material with high viscosity is supplied, the pressure at the front of the kneading roller will increase extremely, causing excessive force to be applied to the rotary screw or the drive device for the rotary screw. Damage may occur.

Therefore, in the case of such a highly viscous resin raw material, the rotating screw must be operated at a lower rotational speed, resulting in a decrease in efficiency.

This invention has a bypass groove for pressure reduction on the kneading roller,
Moreover, by making the cross-sectional area of the bypass groove larger on the inlet side and smaller as it approaches the outlet side, the present invention aims to prevent an excessive rise in pressure within the extruder and provide an extruder with excellent kneading action.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, an extruder 1 has a heating cylinder 4 having an input port 2 for resin raw material at the right end and a discharge port 3 at the other end, and discharges the resin raw material inserted into the heating cylinder 4 from the input port 2. and a rotating screw 5 for conveying to the outlet 3.

The heating cylinder 4 has a first vent hole 6 and a second vent hole 7.
A band heater 8 is provided on the outer periphery.

A kneading roller 9 is integrally provided at a position near the input port 2 side of the second vent hole 7 in the rotary screw 5.

As shown in FIGS. 2 and 3, this kneading roller 9 has several helical grooves 10 arranged in the same helical direction as the helical direction of the rotary screw 5 on its outer peripheral surface at regular intervals in the circumferential direction. It is formed into a shape.

The outer peripheral edge of the side wall surface 10a on the exit 3 side of the spiral groove 10 is chamfered to form a guide surface 10b.

Furthermore, a plurality of bypass grooves 11 parallel to the axis of the kneading roller 9 are provided at appropriate intervals on the outer surface, and end portions 11a and llb on both sides of each bypass groove 11 are opened to both sides of the kneading roller 9.

The cross-sectional area of the bypass groove 11 is large on the inlet side and becomes smaller toward the outlet side.

The resin raw material charged into the input port 2 of the extruder configured as described above is heated by the heating cylinder 4 while being transferred to the discharge port 3 side under the transfer action of the rotating screw 5 rotating in the direction of the arrow. After being evacuated in the first vent hole 6 while being melted, as it passes through each spiral groove 10 of the rotary screw 5, it is kneaded by the stirring action of each spiral groove 10 and moves toward the discharge port 3. be transported.

After the kneaded resin raw material is vented through the second vent hole 7, it is discharged from the discharge port 3.

If a highly viscous resin raw material is introduced into the extruder, the resistance of the kneading roller 9 through the spiral groove 10 will increase.
The resin pressure tends to rise, but because of the presence of the bypass groove 11, some of the resin raw material escapes from the bypass groove 11 to the outlet 3 side, thereby preventing the resin pressure from rising excessively.

In this case, since the bypass groove 11 communicates with the spiral groove 10, the resin raw material escaping from the bypass groove 11 moves into the spiral groove 10 and does not pass through the kneading action without being kneaded.

Further, the cross-sectional shape of the bypass groove is not limited to that of the above embodiment, but may be the shape shown in FIG. 4.

As shown in the examples above, the extruder of the present invention is equipped with a bypass groove that opens at both ends of the kneading roller. Since it is possible to prevent an excessive pressure rise by discharging the resin into the tank and reducing the pressure, it is possible to increase the rotation speed of the rotary screw and to mix and process even highly viscous resin materials without reducing the rotation speed of the rotary screw, greatly improving processing capacity. can do.

Moreover, the cross-sectional area of the bypass groove is large on the inlet side and becomes smaller toward the outlet side, which reduces the amount of resin raw material that passes through the bypass groove without being kneaded, and ensures sufficient kneading effect at the waist kneading roller section. can be raised.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view. FIG. 2 is a side view of the kneading roller. FIG. 3 is an enlarged cross-sectional view taken along the line IV-rV in FIG. FIG. 4 is a sectional view showing another embodiment. 2... Input port, 3... Outlet port, 4...
- Cylindrical heating cylinder, 5...Rotating screw, 9
・・・・・・Kneading roller, 10・・・・・・firing,
11...Bypass groove.

Claims (1)

[Scope of utility model registration request] A screw is rotatably inserted into a cylindrical heating cylinder having a raw material input port at one end and a raw material discharge port at the other end. In an extruder in which a screw-like kneading roller is formed by providing a spiral groove, the kneading roller is provided with a bypass groove that opens at both ends of the kneading roller, and the cross-sectional area of the bypass groove is made larger on the inlet side and larger on the outlet side. An extruder characterized by being extremely small.