JPS6092822A - Extruder equipped with material supply controlling device - Google Patents

Abstract

PURPOSE:To keep the material supplying rate properly and stably and consequently prevent the over-loading phenomenon from developing and accordingly obtain a satisfactory molded part by a structure wherein a pivotable damper is installed at the lower end of a wall surface on the material gripping side of a hopper cylinder. CONSTITUTION:A damper 5, which is pivotally supported by a revolving shaft 6 and the gripping angle of which is properly changed in accordance with the material supplying state, is installed at the lower end of a wall surface on the material gripping side or downstream side of a hopper cylinder. The lower edge of the damper 5 is formed with two circular arcs, the diameters of which are same as those of the inside diameters of the cylinder. The tip of the damper 5 is so constituted as to contact with a sleeve 3 with the radius of gyration of the tip.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a thermoplastic resin extruder equipped with a material supply amount adjusting device. In an extruder, if the amount of material supplied is not appropriate and stable, not only will it not be possible to obtain a good molded product, but there is a risk that an excessive load will be applied to the screw and damage the extruder.

Conventionally, the methods of feeding materials with low bulk density or materials with irregular shapes to an extruder include forcibly feeding the material using a vertical screw feeder, or feeding the material with low bulk density into pellets. A method is used to ensure quantitative transfer to the feeder through secondary processing such as increasing the bulk density and making the grain shape uniform using a mill or the like. Furthermore, in order to efficiently and quickly push the supplied material into the cylinder, as shown in Figures 1 and 2, the lower end of the screw tip side wall surface (hereinafter referred to as the biting side wall surface) of the hopper opening of the hopper cylinder is An undercut is provided.

However, the above conventional technology has the following drawbacks. That is, although it is necessary to mold a variety of materials, if the hopper is fully supplied with a material that originally has a high bulk density or a material that has a high bulk density due to the secondary processing, the material will not reach the undercut portion. The amount of biting is large and overload phenomenon is likely to occur, and especially in a twin-screw extruder, this biting property is strong, so this adverse effect is great and there is a high risk of damage to the extruder. Therefore, it is necessary to starve the material in some parts of the hopper and feed it in a precise quantity using the feeder. For example, scraps produced during the production of films such as polyester (PI!T) are in the form of chips and have a bulk density of 0.0.
It has 3 to 0.4 g/crA, but when it is grouped in a twin-screw extruder, if it is fed into a hopper full,
Those having a bulk density of 0.03 to 0.2 can be molded, but those having a bulk density of 0.2 or more cause an overload phenomenon and cannot be molded.

The present invention aims to overcome the drawbacks of the above-mentioned conventional devices. The present invention has an externally rotatable damper attached to the lower end of the biting side wall of the hopper cylinder, and by adjusting the biting angle by rotating the damper, the material supply amount can be maintained appropriately and stably. This makes it possible to prevent overload phenomena and obtain good molded products. Furthermore, if necessary, a gate plate is slidably installed on the side of the hopper, making it possible to more appropriately control the amount of material supplied.

The present invention will be explained below based on examples. 3 is a vertical cross-sectional view of the material supply section of the twin-screw extruder in the longitudinal direction of the cylinder, FIG. 4 is a perspective view of the damper 5, and FIG. 7 is the same as in FIG. 3.
It is an AA sectional view. That is, a damper 5 supported by a rotary shaft 6 is installed at the lower end of the material biting side wall surface of the hopper cylinder 1 on the downstream side. The damper 5 is rotatable by a rotating shaft 6, and the biting angle (θ) can be changed as appropriate depending on the material supply state, as shown in FIGS. 5 and 6. The lower edge of the damper 5 is formed by two circular arcs having the same diameter as the inner diameter of the cylinder, and the tip of the cough damper 5 is structured to contact the sleeve 3 with its rotation radius. As shown in FIGS. 7 and 8, the biting angle (θ) is changed using a handle 7 provided at the end of the rotating shaft 6 that protrudes from the side of the cylinder. A fixed value is maintained during the forming process by engagement with a bolt 9 provided in the portion 8 via a spring and a hole 10 bored with a predetermined gap in the cylinder side wall.

Furthermore, in the embodiment of the present invention, gate plates 15 are provided on both sides of the hopper to adjust the amount of material supplied. 15' is slidably attached to the hopper π.

As shown in Fig. 3, the gate plate 15.15'' is fixed to the sleeve 3 by a hole 8°187.
16' through threaded rods 17 and 17, respectively.

Umata gate board 15. '15 each slides into contact with the back side of the hopper wall. That is, by rotating the handle 19.19 provided at the tip of the threaded rod 17, 17', the gate plate 15.15 is moved up and down, and the opening length (, e
) can control the material supply amount. FIG. 3 shows a state in which the aperture length (A) is at its narrowest.

As described above, according to the present invention, it is possible to overcome the drawbacks of the conventional apparatus described above, and there is no need for secondary processing of the feed material as in the past, and there is no need to provide an expensive feeder. The effect is also extremely significant.

[Brief explanation of drawings]

Fig. 1 is a vertical joint view of the hopper cylinder undercut section of the conventional device, Fig. 2 is a front view of the interspace, and Fig. 3 is a longitudinal sectional view of the material supply section of the twin screw extruder according to the embodiment of the present invention. Figure 4 is a perspective view of the damper, Figures 5 and 6 are the biting angle (θ
), FIG. 7 is a sectional view taken along line AA in FIG. 3, and FIG. 8 is a left side view of FIG. 7. ■... Extruder cylinder, 2... Screw, 3...
... Sleeve, 4... Hopper, 5... Damper,
6...Rotating shaft, 7...Handle, 8...I ridge, 9...Bolt, 10...Hole, 15.15'...
Gate plate, 16.16'... Case, 17, 17...
・Threaded rod, 18.18'...Bolt, 19゜19ζ・
- Threaded handle. Patent Applicant Japan Steel Works Co., Ltd. Agent Yasushi 1) Yuzo Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (2)

[Claims] (1) An extruder characterized in that a damper is rotatably supported from the outside of the extruder at the lower end of the wall surface on the side of the screw tip of the hopper opening of the hopper cylinder. (2) In an extruder, a damper is rotatably supported from outside the extruder at the lower end of the side wall of the screw end of the hopper opening of the hopper cylinder, and a gate plate is slidably installed on the side wall of the hopper. Characteristic extruder.