JPH05337947A - Method and device for automatically changing liquid color - Google Patents

Abstract

PURPOSE:To change colors efficiently with excellent working steps and workability, preventing liquid sag completely. CONSTITUTION:A plasticizing device is moved to a plasticizing backward limit position. Purging is performed by the specified number of shots under a color change condition so as to perform color changing of a heating cylinder. Next, the plasticizing device is moved to a plasticizing forward limit position so as to confirm a nozzle touching, color change molding is performed by the specified number of shots under a color change molding condition, and mass molding is performed by the specified number of shorts under a mass molding condition. An agitating pump of a present color is stopped by the specified number of shots during the mass molding so as to be rotated reversely, at the same time, an agitating pump of the next color is rotated. When the mass molding of the present color is completed, supply of liquid color of the next color is started, so that the next color can be obtained quickly and the number of shots necessary for changing colors can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid color ring automatic color changing method and a liquid color ring automatic color changing device.

[0002]

2. Description of the Related Art Conventionally, when coloring a resin, a commercially available liquid color is used and the liquid color is supplied into a heating cylinder below a hopper. When changing the color of the liquid color, rotate the pump head of the fan pump and inject the liquid color into the heating cylinder under the hopper to supply the liquid color, and the liquid color mixes and kneads with the resin by its own weight. , To color the resin.

At this time, the resin retained in the heating cylinder is removed by injecting the resin from the injection nozzle at high pressure or purging. 2 is a conceptual diagram of a conventional liquid coloring color changing method, FIG. 3 is a schematic diagram of a conventional liquid coloring color changing device, and FIG. 4 is a time chart of the conventional liquid coloring color changing method.

2 and 3, 11 is an injection molding machine and 12 is an agitating pump. The agitating pump 12 is rotated by receiving a measurement signal from the control device of the injection molding machine 11. The agitating pump 12 has an automatic metering and injecting device 13, the rotation speed of which is controlled by the automatic metering and injecting device 13, and the liquid color is injected while being metered. 15
Is a liquid color bottle containing a liquid color, 1
Reference numeral 6 is a pump head, 17 is a liquid color supply tube, 19 is a hopper, 20 is a heating cylinder, and 21 is a screw arranged in the heating cylinder 20 so as to be movable back and forth.

In this case, two types of pump heads 16 and three types of supply tubes 17 are provided, and the pump heads 16 and the supply tubes 17 are selected according to the supply amount of the liquid color. The tip of the supply tube 17 faces the inside of the heating cylinder 20 below the hopper 19,
The liquid color is mixed with the resin supplied from the hopper 19. The resin and liquid color are
As the screw 21 rotates in the heating cylinder 20, it is kneaded and the resin is colored.

In the liquid coloration color changing device having the above-mentioned structure, the liquid color is sucked from the liquid color bottle 15 by the automatic metering and injecting device 13 of the fan pump 12, is weighed, and is fed through the supply tube 17 to the hopper 1.
Supplied under 9. In this case, the color change of the liquid color is performed by replacing the supply tube 17 or the equipment of the fan pump 12. And
The timing of supplying the liquid color of the next color is synchronized with the metering signal sent from the injection molding machine 11 to the automatic metering injection device 13. The shade of coloring on the resin can be changed by changing the set value of the liquid color supply amount in the automatic metering and injecting device 13.

Next, the operation of the liquid coloring color changing method will be described with reference to FIG. First, the injection molding machine 11 and the fan pump 12 are stopped, and the supply tube 17
Is once removed from under the hopper 19, and the liquid color bottle 15 is also removed. Next, the injection molding machine 11 is operated in the manual operation mode, and the color of the heating cylinder 20 is changed by purging. The purging is carried out in two stages for the screw main body part and for the screw head and the injection nozzle.

For the purging of the screw body, the measured value is 1 / 2,2 of the maximum stroke of the screw.
/ 3, and the injection speed and injection pressure are low for safety. The purging of the screw head and the injection nozzle has a measured value of 5 to 10 [mm], and an injection speed and an injection pressure are increased. Depending on the molten resin,
The resin adhering to the inner wall of the heating cylinder 20 and the surfaces of parts such as the screw head and the injection nozzle is removed.

Next, the next color liquid color bottle 1
5 is connected to the fan pump 12, the supply tube 17 is attached below the hopper 19, a calibration operation is performed in the manual operation mode, and liquid color is supplied from the liquid color bottle 15 to the supply tube 17. Then, after confirming that the liquid color has been completely discharged from the tip of the supply tube 17, the supply tube 17 is attached below the hopper 19 and the liquid color is injected and supplied.

Finally, the heating cylinder 2 is operated in the manual operation mode.
A color change of 0 is performed by purging, and the liquid color is replaced with the liquid color of the next color. In the liquid color ring color changing method having the above-described configuration, when the fan pump 12 is stopped, the liquid color leaks from the supply tube 17 and liquid dripping occurs. Therefore, various methods have been provided to prevent dripping.

That is, when the manual operation mode is selected, the control switch is turned off and the pump head 16 of the fan pump 12 is rotated in the reverse direction to prevent dripping, and the viscosity of the liquid collar is increased to prevent dripping. There are provided, for example, one for adjusting the number of revolutions of the fan pump 12 to prevent dripping, and another for replacing the supply tube 17 or the pump head 16 to prevent dripping.

[0012]

However, in the above-mentioned conventional liquid coloring color changing method, the setup property is poor and the workability is deteriorated. That is, the operator needs to operate the injection molding machine 11 every time each process is executed, and the time constrained for the operation, that is, the downtime becomes long.

Further, since it is difficult to set a program for changing the color of the heating cylinder 20, not only a time loss occurs, but also a time required for exchanging the liquid color bottle 15 of the next color. It takes a long time to discharge a large amount of resin before the next color is obtained, resulting in a decrease in workability. Further, it is difficult to adjust the supply amount of the liquid color in the manual operation mode and the supply amount by the automatic metering injection device 13 during the continuous molding.

Further, the liquid color adheres to and remains on the wall surface of a water-cooled cylinder (not shown) arranged below the hopper 19, and the color cannot be changed sufficiently. Furthermore, it is impossible to completely prevent dripping, and it is impossible to efficiently change colors. That is, when the manual operation mode is selected, the control switch is turned off, and the fan pump 1
In the one in which the second pump head 16 is rotated in the reverse direction to prevent dripping, if the manual operation mode of the fan pump 12 is selected due to an operation error even in the fully automatic operation mode, the hopper 19 The liquid color is excessively supplied into the heating cylinder 20 below. Further, in the fully automatic operation mode, the pump head 16 cannot be rotated in the reverse direction, and the operator must operate the fan pump 12 to rotate the pump head 16 in the reverse direction. If the number of rotations when the pump head 16 is rotated in the reverse direction is fixed, dripping will occur due to differences in the viscosity of each liquid color, the diameter of the supply tube 17, and the like.

Further, in the case of increasing the viscosity of the liquid color to prevent dripping, it is difficult to adjust the viscosity when the viscosity is increased, and the physical properties, dispersibility and pigment precipitation of the liquid color on the resin are affected. Will end up. further,
In the case of adjusting the rotation speed of the agitating pump 12 to prevent dripping, if the rotation speed is lowered, the liquid color cannot be supplied at the time of continuous molding.

In the case of replacing the supply tube 17 and the pump head 16 to prevent dripping, since there are few kinds of the supply tube 17 and the pump head 16, dripping cannot be sufficiently prevented. The present invention solves the problems of the above liquid coloring color changing method, has good setup performance and high workability, and can completely prevent dripping, and efficiently perform color changing. It is an object of the present invention to provide a liquid color ring automatic color changing method and a liquid color ring automatic color changing device that can be used.

[0017]

Therefore, in the liquid color ring automatic color changing method of the present invention, the plasticizing device is moved to the plasticizing backward limit position, and purging is performed for a predetermined number of shots depending on the color changing condition. Change the color of the heating cylinder, move the plasticizing device to the plasticizing forward limit position, check the nozzle touch, perform the color change molding for the expected number of shots according to the color change molding conditions, and perform the number of planned shots according to the mass production molding conditions. Mass production molding is performed.

Then, the fan pump of the current color is stopped and reversely rotated at the preset number of shots during mass production molding, and at the same time, the fan pump of the next color is rotated. Further, in the liquid color ring automatic color changing device of the present invention, the screw is arranged in the heating cylinder so as to be movable back and forth, and the resin is supplied from the hopper into the heating cylinder.

Then, the liquid color is housed in the liquid color bottle, and the fan pump capable of rotating in the normal and reverse directions sucks and discharges the liquid color in the liquid color bottle. A supply tube is provided to supply the liquid collar discharged by the fan pump onto the heating cylinder below the hopper. A water-cooled cylinder is arranged under the hopper, and a wall surface of the water-cooled cylinder is plated so as to prevent the liquid collar from adhering thereto.

[0020]

According to the present invention, as described above, the plasticizing device is moved to the plasticizing backward limit position, and purging is performed by the predetermined number of shots according to the color changing condition to change the color of the heating cylinder. Therefore, the resin discharged from the injection nozzle by the purging is dropped as a purge lump.

When the color change of the heating cylinder is completed,
The plasticizer is moved to the plasticization advance limit position, the nozzle touch is confirmed, color change molding is performed for a predetermined number of shots according to the color change molding conditions, and mass production molding is performed for a predetermined number of shots according to the mass production molding conditions. Then, the fan pump of the current color is stopped and reversely rotated at a preset number of shots during mass-production molding, and at the same time, the fan pump of the next color is rotated.

Therefore, when the mass production molding of the current color is completed, the supply of the liquid color of the next color is started, so that the amount of resin discharged for color change is reduced. Further, in the liquid color ring automatic color changing device of the present invention, the screw is arranged in the heating cylinder so as to be movable back and forth, and the resin is supplied from the hopper into the heating cylinder.

Then, the liquid color is housed in the liquid color bottle, and the fan pump capable of rotating in the forward and reverse directions sucks and discharges the liquid color in the liquid color bottle. A supply tube is provided for supplying the liquid collar discharged by the fan pump onto the heating cylinder below the hopper. When changing the color of the liquid color, the fan pump is rotated in the reverse direction to prevent dripping.

A water-cooled cylinder is disposed under the hopper, and the wall surface of the water-cooled cylinder is plated to prevent the liquid collar from adhering thereto. Therefore, when the next color liquid color is supplied, it does not mix with the current color liquid color.

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a time chart of a liquid coloring automatic color changing method showing an embodiment of the present invention, and FIG. 5 is a schematic view of a liquid coloring automatic color changing device to which the embodiment of the present invention is applied.

As shown in FIG. 1, the color change of the liquid color is performed by purging twice and color change molding once for each cycle, and mass production molding is started after the color change molding is performed. It has become. Therefore, each color change condition in each purging, each color change molding condition in color change molding, mass production molding condition in mass production molding, and the expected number of shots in each process are preset by the setter and stored in the memory. There is.

The memory stores two color change conditions, one color change molding condition, and one mass production molding condition for one color change. For example, when three color changes are performed, 12 Conditions are stored. Then, each time the process is changed, the above conditions are sequentially read from the memory. Therefore, the injection molding machine 11 (see FIG. 2) automatically performs the first purging, the second purging, the color change molding, according to the settings stored in the memory such as the respective conditions and the planned number of shots. Mass production molding can be performed. In this case, the control device of the injection molding machine 11 outputs an ON / OFF signal to the automatic metering and injecting device 13, and the fully automatic operation mode is selected by the signal.

In FIG. 5, 11 is an injection molding machine, 31-31.
Reference numeral 33 is a liquid color supply tube. The supply tubes 31 to 33 are respectively connected to separate unillustrated fan pumps 12 (see FIG. 3), and the fan pumps 1
Liquid colors are supplied from separate liquid color bottles 15 via two pump heads 16. Further, 19 is a hopper, 20 is a heating cylinder, and 21 is a screw arranged in the heating cylinder 20 so as to be movable back and forth.

In this case, the supply tubes 31 to 33
Has a tip facing the inside of the heating cylinder 20 below the hopper 19 so that the liquid color is mixed with the resin supplied from the hopper 19. The resin and the liquid color are kneaded as the screw 21 rotates in the heating cylinder 20, and the resin is colored. Reference numeral 35 is a water-cooling cylinder for cooling the resin supplied from the hopper 19 into the heating cylinder 20.

For example, when performing color change of three liquid colors, three fan pumps 12 are installed, three liquid color bottles 15 are connected to the fan pumps 12, and the fan pumps 12 are supplied with the liquid. Tubes 31 to 3
Connect 3. Since the three fan pumps 12 can be independently controlled, the setup time for color change can be shortened and the time loss can be reduced.

Further, in order to prevent dripping when changing the color of the liquid color, the agitating pump 12 can be automatically rotated in the reverse direction.
It can be easily changed on the settings panel. When the screw 21 rotates and tries to bite the resin supplied from the hopper 19, the tips of the supply tubes 31 to 33 are swung in the rotation direction.
Therefore, the supply tubes 31 to 3 are provided under the hopper 19.
3 is fixed.

When the supply tubes 31 to 33 are fixed under the hopper 19, if the liquid color adhering to the surface of the resin adheres to the wall surface of the water cooling cylinder 35, the second liquid color is supplied. Sometimes it mixes with the previous liquid color. Therefore, the wall surface of the water-cooled cylinder 35 is subjected to a plating treatment that makes it easy to drop even if the liquid collar adheres.

Further, if the tip of the supply tubes 31 to 33 has a wide contact surface with the resin, the resin adheres to the tips of the supply tubes 31 to 33 during the rotation of the screw 21, so that the tips are notched vertically. .. Next, the operation of the liquid color changing automatic color changing device having the above structure will be described.

First, when the fully automatic operation mode is selected, the plasticizing device (not shown) is retracted, and the injection nozzle is placed at the plasticizing retract limit position farthest from the fixed platen.
The plasticizing device is driven by an electric motor, a hydraulic cylinder, or the like (not shown) to move backward, and a plasticizing backward limit position is detected by a limit switch or the like, and is stopped. Then, purging is started and the color of the heating cylinder 20 is changed. At this time, air blow is performed in front of the injection nozzle. That is, air is blown to the resin discharged from the injection nozzle by purging, and the resin is forcibly deflected by the air and falls as a purge lump on the chute.

Since the purging is performed twice and the color changing conditions are made different, the amount of resin discharged can be reduced. Subsequently, the color change molding is performed at a high pressure for a predetermined number of shots, and the color change of the hot runner is performed. Therefore, after measuring to the measurement value setting position of the color change molding condition, the plasticizing device moves forward and moves to the plasticization forward limit position, and when the nozzle touch is confirmed, the color change molding is started.

When the color change molding is performed for the predetermined number of shots, mass production molding is automatically started, and the mass production molding is performed for the predetermined number of shots. When the mass-production molding is completed, the mold clamping device ejects the molded product by the ejector pin and then closes the mold to stand by without generating a mold clamping force. Next, the plasticizing device is automatically retracted and moved to the plasticization retracted limit position to prepare for the next color change.

In this case, at the same time when the first purging is started, the control device instructs the automatic metering and injecting device 13 to supply the coloring liquid color into the heating cylinder 20 under the hopper 19. Then, after the second purging and color change molding processes, the mass production molding process is started.
During mass-production molding, the fan pump 12 of the current color is stopped and the supply of the liquid color of the current color is stopped at the preset number of shots before the scheduled number of shots is completed.

Then, the fan pump 12 of the current color is rotated in the reverse direction to prevent dripping, and the fan pump 12 of the next color is rotated.
Is rotated and the next color liquid color is supplied. In this case, the current color of the fan pump 1
The stop of 2 and the rotation of the fan pump 12 of the next color are performed at the same time. Therefore, the amount of resin discharged during purging can be reduced.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0040]

As described above in detail, according to the present invention, the plasticizing device is moved to the plasticizing backward limit position, and purging is performed by the predetermined number of shots according to the color changing condition to change the color of the heating cylinder. To do. Therefore, the resin discharged from the injection nozzle by the purging is dropped as a purge lump.

When the color change of the heating cylinder is completed,
The plasticizer is moved to the plasticization advance limit position, the nozzle touch is confirmed, color change molding is performed for a predetermined number of shots according to the color change molding conditions, and mass production molding is performed for a predetermined number of shots according to the mass production molding conditions. Then, the fan pump of the current color is stopped and reversely rotated at a preset number of shots during mass-production molding, and at the same time, the fan pump of the next color is rotated.

Since the supply of the liquid color of the next color is started when the mass production molding of the current color is completed, the next color can be obtained quickly and the number of shots required for color change can be reduced. This reduces the amount of resin discharged. Also, since the planned number of shots for each process is set in advance, each process can be performed automatically, the time for which the operator is restrained is shortened, and the setup performance can be improved, which improves workability. Is improved.

Further, in the liquid color ring automatic color changing device of the present invention, the screw is arranged in the heating cylinder so as to be movable back and forth, and the resin is supplied from the hopper into the heating cylinder. Then, the liquid color is housed in the liquid color bottle, and the fan pump capable of rotating in the forward and reverse directions sucks and discharges the liquid color in the liquid color bottle. A supply tube is provided for supplying the liquid collar discharged by the fan pump onto the heating cylinder below the hopper.

When changing the color of the liquid color, it is possible to prevent the fan pump from rotating in the reverse direction to cause dripping. Therefore, the next color can be obtained quickly, the number of shots required for color change can be reduced, and the amount of resin discharged can be reduced. A water-cooled cylinder is arranged under the hopper, and a wall surface of the water-cooled cylinder is plated to prevent the liquid collar from adhering thereto. Therefore, when the next color liquid color is supplied, it does not mix with the current color liquid color.

[Brief description of drawings]

FIG. 1 is a time chart of a liquid coloring automatic color changing method according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a conventional liquid coloring color changing method.

FIG. 3 is a schematic view of a conventional liquid color ring color changing device.

FIG. 4 is a time chart of a conventional liquid coloring color changing method.

FIG. 5 is a schematic view of a liquid color ring automatic color changing device to which an embodiment of the present invention is applied.

[Explanation of symbols]

 12 Induction Pump 15 Liquid Color Bottle 19 Hopper 20 Heating Cylinder 21 Screws 31-33 Supply Tube 35 Water Cooling Cylinder

Claims (2)

[Claims] 1. A plasticizing device is moved to a plasticizing backward limit position, and (b) purging is performed for a predetermined number of shots according to a color changing condition to change the color of a heating cylinder, and (c).
The plasticizing device is moved to the plasticizing forward limit position, the nozzle touch is confirmed, and (d) color change molding is performed for a predetermined number of shots according to the color change molding conditions, and (e) mass production is performed for a predetermined number of shots according to the mass production molding conditions. (F) Liquid color characterized by (f) stopping the fan pump of the current color and rotating it in reverse at the preset number of shots during mass production molding, and simultaneously rotating the fan pump of the next color Ring automatic color change method. 2. (a) a heating cylinder; (b) a screw disposed in the heating cylinder so as to move back and forth; (c) a hopper for supplying resin into the heating cylinder; and (d) a liquid collar. And a liquid color bottle to accommodate
(E) A fan pump that is rotatable in forward and reverse directions and that sucks and discharges the liquid color in the liquid color bottle; and (f) the liquid color discharged by the fan pump under the hopper. A liquid supply tube for supplying the heating cylinder; and (g) a water-cooled cylinder which is disposed under the hopper and which has a wall surface subjected to a plating treatment for preventing the liquid collar from adhering. Coloring automatic color changing device.