JPH10278081A - Plasticizing device for injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and completely change a color by mounting a mixing nozzle having a mixing element at an end of a barrel for receiving a rotatable screw movable in an axial direction of a predetermined block, and providing an opening of a coloring agent passing passage having a check valve of a backflow from the barrel side at an axial center of the screw. SOLUTION: Material resin is conveyed forward of a screw 14 by heating to melt the resin by a heater on an outer periphery of a barrel 13, a predetermined amount is metered, and coloring agent is supplied from an end opening of a coloring agent passage 15 with a check valve 16 of melted resin backflow at an axial center of the screw 14 to metered melted resin. The forward coloring agent supplied and metered melted resin is injected in a mold cavity via a mixing nozzle 12 by a forward operation of the screw 14 from a retracting limit. The metered resin is mixed and the agent is dispersed to become a colored or marble pattern molding by a mixing element 14 at the time of passing the nozzle 12, no agent is adhered to the barrel or screw, and hence disassembling and cleaning of an apparatus are not required, and color change can be simply and completely conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasticizing device for an injection molding machine, and more particularly to an improvement in a plasticizing device for efficiently changing the color of a material resin containing a colorant.

[0002]

2. Description of the Related Art Conventionally, a coloring method using a plasticizing apparatus of this kind is based on a method of plasticizing a liquid, such as a colorant, a liquid color, a masterbatch, a color resin, or a solid melt, from a hopper port for charging a raw material or a middle of a screw. Had been put into the gasifier.

[0003]

Therefore, the colorant adheres to the inner wall surface of the barrel, the valley portion of the screw, the outer diameter surface, and the like. In order to change the color, the plasticizer had to be disassembled and cleaned, which was very troublesome.

[0004] In marble molding, the marble pattern is determined by the mixing ratio of the raw material and the colorant supplied to the plasticizer, and the marble pattern during the injection process cannot be controlled.

It is an object of the present invention that the above-mentioned color change takes time, is incomplete, and it is necessary to disassemble and clean the plasticizing device for complete color change. It is an object of the present invention to provide a plasticizing apparatus for an injection molding machine, which eliminates the disadvantage that the marble pattern cannot be controlled.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a plasticizing device for an in-line screw type injection molding machine, wherein a tip of a barrel having a rotatable and axially movable screw inserted thereinto is inserted. A mixing nozzle having a mixing element, and a check valve for preventing backflow from the barrel side is provided at an axial portion of the screw, and a passage through which a coloring agent passes is opened. Plasticizer.

[0007] Further, a screw inserted rotatably into the inner diameter surface of the barrel and a pre-plasticization device for plasticizing the plastic material by a heating device provided on the outer peripheral surface of the barrel, a torpedo attached to the tip of the pre-plasticization device and the torpedo A mixing nozzle having the mixing element previously attached, and a switching valve mounted between the pre-plasticizing device and the torpedo via a switching valve, for introducing and measuring the molten resin from the pre-plasticizing device and adding a colorant. In a plasticizing device of an injection molding machine having an injection device for injecting a measuring resin through the mixing nozzle by an injection plunger which is inserted and retracted into an injection barrel, the injection plunger has a central axis from the barrel side. A check valve to prevent backflow is provided.A passage for colorant is provided.A passage is opened at the tip of the injection plunger. Was plasticized device for an injection molding machine, characterized in that the.

The passage through which the colorant passes may be provided at the center axis of the torpedo provided in front of the mixing nozzle, instead of being provided at the injection plunger, or may be provided at the tip of the injection device.

Since the supply amount and time of the colorant as described above can be freely adjusted and controlled, and can be supplied into the measured resin from the center of the screw or the injection plunger, the colorant can be supplied to the barrel inner surface or the screw. And the marble pattern can be freely controlled even in marble molding.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A switching valve is provided upstream of a torpedo in a pre-plasticizing apparatus in which a plasticizing device of an in-line screw type injection molding machine or a pre-plasticizing device having a mixing nozzle having a torpede and a mixing element mounted at the tip thereof is mounted. Introduce the molten resin from the pre-plasticizer installed
In a plasticizing apparatus of an injection molding machine having an injection device for measuring and adding a colorant and injecting a measurement resin through the mixing nozzle by an injection plunger, a screw, an injection plunger, a torpedo or an injection barrel center is provided. Thus, the supply amount and time of the colorant can be freely adjusted and controlled.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. 1 taking a plasticizing device of an in-line screw type injection molding machine as an example. A plasticizing device 10 is provided with a mixing nozzle 12 provided with a mixing element 11 at the tip. Attached barrel 1
A screw 14 is rotatably and movably inserted in the axial direction by a predetermined distance in the inner diameter portion of the screw 3. It is heated by a heating device provided on the outer peripheral surface of the barrel 13, melted, conveyed to the front of the screw 14 (leftward in the figure), and weighed by a predetermined amount.

A passage 15 for passing a colorant is provided in the axial center of the screw 14 and is opened at the tip of the screw 14 so that the molten resin measured in front of the screw 14 as described above can be used. A colorant is supplied. This passage 15 is provided with a check valve 16 so that there is no backflow of the molten resin from the barrel side. .

Since the configuration is as described above. The molten resin metered in front of the screw 14 to which the colorant has been supplied is moved forward (moves leftward in the figure) from the retreat limit of the screw 14 through the mixing nozzle 12 to form a mold cavity (not shown). It is injected inside. When the metering resin passes through the mixing nozzle 12, it is mixed by the mixing element 11, and the coloring agent is dispersed to form a colored molded product or a molded product having a marble pattern.

Next, another embodiment of the present invention will be described.
Reference numeral 0 denotes a pre-plasticizer, in which a screw 22 is rotatably inserted into the inner diameter surface of the barrel 21, and a raw material supply (not shown) is supplied by rotation of the screw 22 and heating from a heating device provided on the outer peripheral surface of the barrel 21. The raw resin from the mouth is melted and kneaded. The tip of the barrel 21 has a torpedo 23 and a mixing element 24 attached thereto.
Is mounted, and an injection device 27 is mounted between the torpedo 23 and the pre-plasticization device 20 via a switching valve 26.

In the injection device 27, an injection plunger 30 fixed to a rod of a piston 29 of an injection cylinder 28 is inserted into the inner surface of the injection barrel 31 so as to be movable in the axial direction by a predetermined distance. When the preliminary plasticizer 20 and the injection device 27 communicate with each other, the molten resin is introduced from the preliminary plasticizer 20 into the injection barrel 31 and the injection plunger 30 provided with the check valve 32 or the check valve 33 is provided. When the coloring agent is supplied from the passage 34 or the passage 35 opened to the axis of the tip of the injection barrel 31 and a predetermined amount of resin is accumulated, the switching valve 26 connects the injection device 27 and the mixing nozzle 25 this time. Since the space between the pre-plasticizing device 20 and the injection device 27 is closed, the injection plunger 30 moves forward (moves downward in the drawing) and is accumulated in the injection barrel 31. Mixing nozzle 25 molten resin that
Through a mold cavity (not shown).

At the time of this injection, the colorant is supplied to the vicinity of the center of the molten resin accumulated in the injection barrel 31, but when passing through the mixing nozzle 25, it is mixed by the mixing element 24 to disperse the colorant. It becomes a colored molded product or a molded product with a marble pattern.

In the above-described embodiment, the passage 34 or the passage 35 through which the colorant passes is formed by the injection plunger 30 or the injection barrel 3 respectively.
Although the example in which the opening is formed at the axial center of the front end of the mixing nozzle 25 is not limited to this, the passage 36 and the check valve 37 may be connected to the mixing nozzle 25.
May be opened at the axis of the torpedo 23 upstream of the torpedo.

[0019]

As described above, the construction and operation described above are performed, and the colorant is supplied to the vicinity of the center of the measured molten resin. There is no contact with the surface, etc., so the colorant does not adhere to the barrel or screw, dismantling the plasticizer,
The color can be easily and completely changed without cleaning, and the disadvantage that the marble pattern cannot be controlled in the marble molding can be eliminated.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment in which the present invention is used for a plasticizing device of an in-line screw injection molding machine.

FIG. 2 is an explanatory view of another embodiment of the present invention, showing a plasticizing device of a plunger type injection molding machine.

[Explanation of symbols]

 10, 20 Plasticizing device 11, 24 Mixing element 12, 25 Mixing nozzle 13 21 Barrel 14, 22 Screw 15, 34, 35, 36 Passage 16, 32, 33, 37 Check valve 23 Torpedo 26 Switching valve 27 Injection device 28 Injection cylinder 29 Piston 30 Injection plunger 31 Injection barrel

Claims (4)

[Claims] 1. A plasticizing device for an in-line screw type injection molding machine, wherein a mixing nozzle having a mixing element is attached to a tip of a barrel into which a screw rotatably and axially movable in a predetermined section is inserted, and a mixing nozzle for the screw is provided. A plasticizing device for an injection molding machine, characterized in that a passage through which a colorant passes is provided, provided with a check valve for preventing backflow from the barrel side at an axis portion. 2. A pre-plasticizing device for plasticizing a resin material by a screw rotatably inserted into an inner peripheral surface of a barrel and a heating device provided on an outer peripheral surface of the barrel, and a torpedo attached to a tip of the pre-plasticizing device. A mixing nozzle having a mixing element attached at the tip thereof, and a switching valve installed between the pre-plasticizing device and the torpedo via a switching valve, introducing and measuring the molten resin from the pre-plasticizing device, and adding a colorant. A plasticizer of an injection molding machine having an injection device for injecting a measuring resin through the mixing nozzle by an injection plunger inserted into the injection barrel so as to be able to advance and retreat. Provided a passage through which the colorant passes, provided with a check valve that prevents backflow from the nozzle, and opened the passage at the tip of the injection plunger. A plasticizer for an injection molding machine. 3. The plasticizing apparatus for an injection molding machine according to claim 2, wherein the passage through which the colorant passes is provided in the center axis of the torpedo in front of the mixing nozzle, instead of the injection plunger. 4. The plasticizer of an injection molding machine according to claim 2, wherein the passage through which the colorant passes is attached to the tip of the injection device.