JPH0696259B2 - Fluid transport device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tandem extruder, a pre-plastic type tandem injection molding machine, and other devices for transporting a liquid phase fluid with a screw, and particularly to a liquid phase from a screw base. TECHNICAL FIELD The present invention relates to a fluid transportation device provided with an improved screw seal for preventing fluid leakage.

(Prior Art) FIG. 4 shows a conventional tandem extruder, in which the liquid phase resin supplied from the raw material hopper 11 and plasticized by the first stage screw 12 is transferred to the second stage cylinder 14 through the connecting pipe 13. It is supplied to the liquid-phase resin supply port 15, further kneaded and homogenized by the second-stage screw 16 and transported, and is molded into a predetermined shape and extruded by the die 17 attached to the tip of the cylinder.

By the way, in this type of extruder, as shown in FIG. 5, the liquid phase resin supplied from the liquid phase resin supply port 15 of the second stage cylinder 14 is supplied to the base of the second stage screw 16 at the rear portion of the cylinder. Mechanical screw seal to prevent leakage
18 are provided. However, in such a mechanical screw seal 18, resin leakage is likely to occur, burnout occurs due to deterioration of the leaked resin, and there are many problems that the molding quality is adversely affected. There is also an operational restriction that the supply pressure of the liquid phase resin to the second-stage cylinder 14 cannot be increased because of poor property.

(Problems to be Solved by the Invention) The present invention solves problems such as leakage of fluid such as resin in a screw base portion in a cylinder, which is supplied as a liquid phase fluid in a conventional tandem type extruder, deterioration, deterioration, etc. At the same time, an attempt is made to obtain a seal portion having higher pressure resistance than the conventional screw seal.

(Means for Solving the Problems) Therefore, the present invention relates to a device for transporting a liquid phase fluid supplied from a cylinder base side by a screw to a cylinder tip end, in which a screw located upstream of the liquid phase fluid supply port is used. A part is used as a pressure-increasing screw and a solid-phase or liquid-phase resin supply port is provided on the downstream side of the pressure-increasing screw, which serves as means for solving the problem.

(Operation) The liquid phase fluid or solid phase body supplied from the supply port of the liquid phase fluid or solid phase body located at the rear end of the pressure rising screw is the main fluid after the liquid phase fluid supply port in front of it by the pressure rising screw. The pressure is increased by the time it reaches the screw portion, and in the case of a solid-phase body, the liquid pressure and the pressure increase are simultaneously performed in the same pressure screw portion. Therefore,
The liquid-phase fluid supplied from the liquid-phase fluid supply port via the connection pipe does not flow toward the screw base portion on the upstream side due to the fluid pressure boosted by the pressure boosting screw,
Moreover, since the rear end of the pressure rising screw is kept at a lower pressure or a solid phase than the front end thereof, it is possible to completely prevent leakage of the liquid phase fluid supplied from the liquid phase fluid supply port from the screw base portion as in the conventional case.

Further, since the fluid pressure at the tip end portion of the pressure boosting screw is sufficiently increased as described above, the supply pressure to the liquid phase fluid supply port can be increased more than before.

(Example) Hereinafter, an example in which the present invention is applied to a tandem extruder will be described with reference to the drawings. FIG. 1 shows a part of a second stage cylinder, which is one of the embodiments, and is a sectional view of the second stage cylinder and the second screw base. In the figure,
Reference numeral 1 is a second-stage cylinder, 2 is a solid-phase resin supply port provided at the base of the second-stage cylinder 1, 3 is a raw material hopper, and 4 is liquid-phase resin supplied from a first-stage cylinder through a connecting pipe 13. Is a liquid-phase fluid supply port, and the supply port 4 is provided at a portion facing the rear end of the main screw 5'of the second stage cylinder.
The lead angle (θb), groove depth (Hb), and groove width (Wb) of the groove of the main screw 5 ′ between the solid-phase resin supply port 2 of the second-stage screw 5 and the main screw 5 ′. The pressure-increasing screw 6 having a groove with a value (θa, Ha, Wa) smaller than any of the above is provided. As shown in FIG. 2, the pressurizing screw 6 serves to plasticize and pressurize the supplied solid phase resin 3a until the main screw 5'after the liquid phase fluid supply port 4 is reached.

In the above structure, the solid phase resin 3a supplied from the hopper 3 through the supply port 2 is the pressure rising screw 6 of the second stage screw 5.
It is sent to the main screw 5'in the state of liquid phase resin while being plasticized in the section and being pressurized. At the tip of the pressure-increasing screw 6, the liquid-phase resin that has been plasticized and sufficiently pressurized is the high-pressure liquid-phase resin 4a that enters from the liquid-phase fluid supply port 4.
Since it prevents the inflow of the molten resin into the base end portion of the screw, the molten resin does not leak at the base portion of the second-stage screw 5.

FIG. 3 shows another embodiment of the present invention, in which the second stage screw 5 is used.
1 is the same as the screw structure of the above embodiment shown in FIG. 1, and in this embodiment, a branch pipe 13a is provided in the connecting pipe 13 connecting the first stage cylinder and the second stage cylinder 1, and the throttle valve 130 Via a pipe 13b to a supply port 2a provided in the screw base of the second stage cylinder 1.

In the apparatus of this embodiment, the high-pressure molten resin supplied from the first-stage cylinder is throttled by the throttle valve 130 and a part of the molten resin is sent to the supply port 2a. The pressure is once reduced, and the pressure is increased again by the pressure increasing screw 6 to be extruded to the main screw 5'side. Therefore, the screw base of the second-stage cylinder 1 is always kept at a low pressure, the high-pressure molten resin supplied from the first-stage cylinder does not reach the screw base, and leakage at the same is prevented.

In the above, only the resin has been described as the substance to be treated, but it goes without saying that the present invention can be applied to other substances having similar properties.

(Effects of the Invention) As described in detail above, according to the present invention, the screw portion upstream of the liquid-phase fluid supply port is used as the pressure-increasing screw, and the solid-phase or liquid-phase resin is provided on the downstream side of the pressure-increasing screw. Since the supply port is provided, the resin in this part is constantly renewed and new resin is constantly supplied, so that the resin in this part deteriorates and becomes a low viscosity, so that the sealing ability decreases. There is no such thing. Further, since the base of the booster screw maintains a low pressure and the tip of the booster screw has a high pressure, even if the pressure of the liquid-phase fluid supplied from the first-stage cylinder is higher than in the conventional case, the pressure of the second-stage cylinder is increased. It does not flow toward the screw base, and the liquid phase fluid does not leak at the same.

[Brief description of drawings]

FIG. 1 is a side sectional view of a second stage cylinder and a screw base portion showing a device of one embodiment of the present invention, FIG. 2 is an explanatory view of the operation of the device, and FIG. 3 is a device of another embodiment of the present invention. FIG. 4 is a side sectional view of a second-stage cylinder and a screw base, FIG. 4 is a side sectional view of a conventional tandem extruder, and FIG. 5 is a side-sectional view of a second stage cylinder and a screw base of the former. Description of main parts of the figure 1 ... Second stage cylinder 2 ... (Solid phase resin) supply port 3 ... Raw material hopper 4 ... Liquid phase fluid supply port 5 '... Main screw 6 ... Booster screw

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location B65G 53/48 7612-3F (72) Inventor Kaoru Takano Iwazuka-cho Takamichi, Nakamura-ku, Aichi Prefecture Nagoya No. 1 Mitsubishi Heavy Industries, Ltd., Nagoya Machinery Works (72) Inventor, Takataka Hasegawa, No. 60, Kutane, Iwazuka-cho, Nakamura-ku, Nagoya, Aichi Prefecture Nakabishi Engineering Co., Ltd. (56) References -40700 (JP, Y1)

Claims (1)

[Claims] 1. A device for transporting a liquid phase fluid supplied from a cylinder base side by a screw to a cylinder tip,
A fluid transportation device characterized in that a screw portion upstream of a supply port for the liquid phase fluid is used as a pressure rising screw, and a supply port for solid phase or liquid phase resin is provided on the downstream side of the pressure rising screw.