JPS62132526A - Mixing head - Google Patents

Abstract

PURPOSE:To prevent the generation of gel in a mixing part by providing both a specified discharge means of a mixed raw material and a feed means of washing fluid in a mixing head wherein plural raw materials are introduced into a clearance between the faces having relative velocity difference and mixed by shearing force. CONSTITUTION:When raw materials A, B are discharged through the discharge ports 8, 9 for the raw materials, the discharge pressure overcomes stress of an elastic body 13, a clearance is formed between the faces 5, 6, and the raw materials are fed to the clearance. According as a rotator 14 is rotated in high speed the raw materials are received with shearing force by the relative velocity difference caused between a concave type cone face 5 and a convex type cone face 6, mixed and injected through an injection port 7. Then when the injection is finished by stopping the feed of the raw materials, the faces 5, 6 are closely stuck by energizing force 15 of the elastic body 13 and the residual mixed liquid is discharged. When washing liquid (gas) is fed under pressure nearly overcoming the energizing force 15 of the elastic body 13, the faces 5, 6 are pushed and opened and the faces 5, 6 are washed by rotating the rotator 14 in high speed while holding the resulting minute clearance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mixing head used for mixing and injecting raw materials in reactive injection molding machines, vacuum casting machines, small dispensers, and the like.

Conventional technology Conventionally, the mixing method involves introducing raw materials into a predetermined container,
There are methods of stirring using blade-type forced stirring devices with various shapes, mixing methods in which the raw materials are divided and mixed while flowing through fixed dividing plates or divided blades, and mixing methods in which the raw materials are divided and mixed while flowing through fixed dividing plates or divided blades. Methods such as mixing by colliding raw materials under high pressure in a container are used.

Problems to be Solved by the Invention Mixing methods that use blade-type forced stirring devices, split plates, or split blades have many voids, resulting in a large amount of mixed liquid remaining, and even if cleaned with gas or cleaning liquid, it is not sufficient. A large amount of cleaning gas or cleaning liquid is required for cleaning, and furthermore, the residual cleaning liquid deteriorates the physical properties of the raw material after curing, which poses problems in terms of production costs and stable production. In addition, although the collision mixing method is suitable for mixing low-viscosity liquids, it is not suitable for sufficiently mixing high-viscosity raw materials mixed with fillers etc. because the mixing force is weak. Another problem was that it required a high-pressure source such as hydraulic pressure.

In order to solve this problem, the present inventor proposed a shear stirring method using a convex conical surface and a concave conical surface having a relative speed difference. A mixed head has already been proposed. This mixing head is good as long as it is used continuously, but gel may form in the mixing part during heating time or when cooling at the end of the process, making it difficult to restart the process.

Means for Solving the Problems In order to solve the above problems, the present invention provides a mixing head that receives a plurality of raw materials in a gap between surfaces having a relative speed difference and mixes them by the shear force between the surfaces. The present invention is characterized by comprising means for timely bringing the surfaces into close contact with each other to discharge the mixed raw material, and means for supplying cleaning fluid by appropriately separating the surfaces after discharging the mixed raw materials.

Preferably, the surfaces are a convex conical surface and a concave conical surface that can be brought into close contact with each other except for the injection port.

In addition, the gap between the two surfaces with a relative speed difference is greatest when multiple raw materials are being injected while being shear-mixed, and when discharging the next mixed raw material, it is almost zero to ensure complete discharge, and when cleaning fluid is supplied, It is preferable to make the width narrower than when mixing to improve the cleaning effect by increasing the resistance to passage of the cleaning fluid. Also preferably, the cleaning fluid is two fluids, first a cleaning fluid flowing through the shearing gap followed by N2 or an inert gas.

It is convenient for the above-mentioned preferred gap adjustment to apply a constant closing pressure between the surfaces and push the surfaces to a predetermined gap in accordance with the supply pressure when supplying raw materials or cleaning fluid. In the state where the surfaces are in close contact, the raw materials having a relative velocity on both surfaces can be flushed out and removed to the outside while cutting off the supply of raw materials to the gap due to the close contact between the surfaces. This can reduce the number of maintenance times for the mixing head.In the case of stable raw materials with zero reactions, it is good to clean them once before stopping the machine, and in the case of fast-reacting raw materials,
It is a good idea to clean regularly even when mixing and injection.

Embodiment FIG. 1 is a front sectional view of a mixing head of the present invention. The mixing head main body 1 has an inlet 2 for raw material A and an inlet 4 for raw material B. Discharge ports 8, 9 for raw materials A and B to the mixing section. A concave conical surface 5 and an injection lower are formed. Further, a rotating body 14 having a convex conical surface 61 and a rotary seal 11 and capable of rotating in the direction of arrow 16 is provided at the center.
An elastic body 13 is activated to bias the conical portion 1o in the direction of . The main body 1 is provided with a cleaning liquid inlet 17 and a cleaning gas inlet 18, as shown in FIG.

Figures 3a, b, and c are schematic diagrams showing the injection cycle, which will be explained using Figures 1 to 3. During mixing,
, 9 overcomes the stress of the elastic body 13 and the surface 5,
A gap Δ1 is formed between 6 and the raw material is supplied to the gap Δ1. The raw material is rotated at high speed by the rotating body 14 (arrow 16 in Fig. 3).
) and are subjected to shearing force due to the difference in relative speed between the concave conical surface 5 and the convex conical surface 6, resulting in agitation and mixing, and the mixture is injected from the injection lower. When the injection is completed by stopping the supply of raw materials, the surfaces 5 and 6 are brought into close contact with the gap Δ2 by the biasing force 15 of the elastic body 13, and the remaining mixed liquid is discharged. Next is the cleaning solution.

By supplying the cleaning gas at a pressure that almost exceeds the biasing force 15 of the elastic body 13, the surfaces 5 and 6 are pushed open as shown by the arrow 21, and the rotating body is made to move at high speed while maintaining a minute gap Δ3. Rotate (arrow 16) to clean surfaces 5 and 6. By stopping the supply of cleaning liquid after cleaning, the biasing force 16 of the elastic body 13 is reduced.
The gap Δ2 is closed by. This is the cycle for cleaning the mix head of the present invention.

Effects of the Invention According to the present invention, it is possible to provide a cleaning cycle at appropriate times when using the mixing head, and by cleaning the mixing head at the time of rest or termination, it is possible to prevent the generation of gel in the mixing section.
Furthermore, even when high viscosity raw materials are used, by periodically cleaning them during the process, it is possible to similarly prevent the generation of gel in the mixing section, so that the number of times of maintenance can be significantly reduced. Further, effective cleaning can be performed with a small amount of cleaning liquid.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of an embodiment of the mixing head of the present invention;
Figure 2 is a plan view of Figure 1, Figure 3 a + b + C is the top view of Figure 1.
It is a schematic cross-sectional view which shows the operation|movement during the cleaning cycle of the figure C part. 5... Concave conical surface, 6... Convex conical surface,
7...Injection port, 10...Gap, 12...
...Cleaning fluid discharge port, 13...Elastic body, 17
...Cleaning liquid inlet, 18...Cleaning gas inlet.

Claims (2)

[Claims] (1) In a mixing head that receives a plurality of raw materials in a gap between surfaces having a relative speed difference and mixes them using a shear force between the surfaces, means for timely bringing the surfaces into close contact and discharging the mixed raw materials; A mixing head characterized by comprising means for supplying a cleaning fluid with an appropriate distance between the surfaces after discharging the mixed raw materials. (2) The mixing head according to claim 1, wherein the surfaces are a convex conical surface and a concave conical surface that can be in close contact with each other except for the injection port.