JPH07186192A - Plastic molder with colorant or cleaner supply unit - Google Patents

Abstract

PURPOSE:To enable color change using small amounts of a purging material by providing a pressure chamber to open and close an exit to a mixing head according to back-and-forth movements of a screw in a resin channel and a heating cylinder in an attachment provided between a mixing nozzle and a heating cylinder's head and by connecting a pressure chamber and a colorant supply unit. CONSTITUTION:A molten resin injected from a heating cylinder 11 goes through a resin channel of an attachment 21 and reaches a mixing nozzle 51. On the other hand, a colorant goes through a colorant channel of the attachment 21 and reaches a pressure chamber 32 from a colorant or cleaner supply unit 71. The pressure chamber 32 has a plunger 33 which moves back and forth according to back-and-forth movements of a screw in the heating cylinder 11, the plunger is advanced by the advance of the screw when a resin is injected and thereby pressurizes a colorant in the pressure chamber 32, discharging the colorant to a mixing nozzle 51. At the same time, the molten resin reaches the mixing nozzle 51, is blended with a colorant and injected. When a color is changed, a cleaner is used in place of a colorant if necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for supplying a coloring agent or a cleaning agent (hereinafter referred to as a coloring agent supplying apparatus).
The present invention relates to a plastic molding machine.

[0002]

2. Description of the Related Art The present inventors have previously proposed a molding machine disclosed in Japanese Patent Laid-Open No. 5-57750 as a molding machine equipped with a colorant supply device. This plastic molding machine has an injection valve having a discharge channel for supplying a coloring agent or a cleaning agent into a heating cylinder of the molding machine and an operating member reciprocating in the discharge channel, and a discharge channel of the injection valve. A colorant supply device provided with a press-fitting device for sending out a colorant or a cleaning agent is attached to a heating cylinder of a molding machine. The colorant supply device can replace the colorant storage container with one containing a desired colorant to change the color, and can also replace the colorant storage container with the cleaning agent storage container to supply the cleaning agent. It is possible. According to this plastic molding machine, it is possible to shorten the supply path of the coloring agent or the cleaning agent, and thereby, it is possible to easily and easily carry out the cleaning at the time of color change.

However, in the above plastic molding machine, since the colorant is supplied to the resin melting portion in the heating cylinder,
Colorant adheres to the inner wall of the heating cylinder and the screw part, and a large amount of purge material (resin and colorant or cleaning agent to be used next) is required to completely remove the adhered colorant when changing colors. There are still problems.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to reduce the amount of the purging material at the time of color change and to economically and easily and reasonably perform color change. An object of the present invention is to provide a plastic molding machine equipped with an agent supply device.

[0005]

According to the present invention, in a plastic molding machine equipped with a coloring agent supply device, one end is connected to the tip of the heating cylinder of the molding machine, and the other end is connected to a mixing nozzle. Depending on the forward and backward movement of the screw in the heating cylinder, a resin flow path is formed on the side portion to connect to the coloring agent or cleaning agent supply device, and guides the molten resin injected from the heating cylinder to the mixing nozzle. Between a pressurizing unit having a pressurizing chamber that is compressed or decompressed by a plunger inserted so as to be movable back and forth to open and close an outlet to the mixing head, and a connecting unit between the pressurizing chamber and the coloring agent supply device. An attachment having a supply channel communicating with the attachment is attached between the mixing nozzle and the tip of the heating cylinder, and a colorant supply device is connected to a connection part with the colorant or cleaning agent supply device. .

[0006]

Function: The molten resin injected from the heating cylinder reaches the mixing nozzle through the resin flow path of the attachment. on the other hand,
The colorant supplied from the colorant supply device connected to the attachment reaches the pressurizing chamber through the colorant channel of the attachment when the resin in the heating cylinder is plasticized, and temporarily accumulates in the pressurizing chamber. . Then, the plunger moves forward in accordance with the advance of the heating cylinder screw at the time of resin injection, and the pressurizing chamber is compressed. This increases the pressure of the colorant in the pressure chamber, opens the outlet to the mixing nozzle, and discharges the colorant in the pressure chamber to the mixing nozzle. At the same time, the molten resin injected from the heating cylinder is injected into the resin flow path of the attachment and reaches the mixing nozzle. Then, it is mixed with the colorant and ejected from the mixing nozzle. In addition, when changing colors, a cleaning agent is used instead of the coloring agent as needed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a side view showing a partial cross section of the vicinity of an attachment of a plastic molding machine according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view showing a colorant being inhaled in the molding machine, and FIG. FIG. 6 is an enlarged cross-sectional view showing a state where a colorant is mixed in the machine.

The plastic molding machine 10 shown in FIGS. 1 to 3 has a rear end of an attachment 21 attached to the front end of a heating cylinder 11 of the injection molding machine.
Mixing nozzle 51 and attachment 2 at the tip of
A colorant or cleaning agent supply device 71 is connected to the side portion of 1. Reference numeral S is a screw.

The attachment 21 is a main body 2
2, a sleeve 29, a plunger 33, an opening / closing ball 35, and an opening / closing ball holding member 34. Body 22
As shown in FIG. 2, the side portion is connected to the coloring agent or cleaning agent supply device 23, and the rear end is connected to the heating cylinder 11.
4, a tubular shape having a connecting portion 25 with the mixing nozzle 51 at the front end, and the sleeve 29 is inserted therein. In addition, each connection part 23, 24, 25
Each of them is formed with a screw for screwing.

The discharge port 72 of the supply unit 71 is inserted into the connecting portion 23 for connecting to the colorant supply unit.
2 communicates with a colorant channel 39, which will be described later, inside. Inside the vicinity of the connection portion 24 with the heating cylinder, an enlarged space 26 is formed in which the rear end communicates with the inside of the heating cylinder 11 and the front end expands. This expanded space 26 becomes a part of a resin flow path for passing the molten resin injected from the heating cylinder 11,
Further, it serves as a pressure adjusting portion for moving the rear end of the plunger 33 back and forth according to the forward and backward movement of the screw S. 27 in the figure
Is an atmosphere opening hole.

The sleeve 29 is provided with a pressing portion 30 having the following structure. That is, the front part is the pressurizing chamber 32.
Is formed in the center axis position of the sleeve 29 so as to penetrate between the front and rear ends, so that the plunger 33 can compress and decompress the pressurizing chamber 32 in the plunger sliding hole 31. It is stored so that it can slide back and forth. At the front end of the pressurizing chamber 32, a cylindrical opening / closing ball holding member 34 having a through hole having a large diameter at the front portion and a small diameter at the rear portion is fitted, and the opening / closing ball holding member 34 has a large diameter hole. An opening / closing ball 35 is housed therein so as to be movable back and forth, and the pressing portion 30 is constituted by them. The small diameter hole at the rear of the open / close ball holding member 34 constitutes an outlet 36 from the pressure chamber 32 to the mixing head, and is opened / closed by the forward / backward movement of the open / close ball 35. A step portion 37 is formed in the middle of the outer surface of the plunger 33, and when the plunger 33 moves forward, it abuts against a step portion 38 on the inner surface of the plunger sliding hole 31,
It defines the most advanced position of the plunger 33.

The outer peripheral surface of the sleeve 29 is partially connected to a discharge port 72 attached to the connecting portion 23 of the colorant supply device, and a front end of the colorant channel 39 is connected to the pressurizing chamber 32. Are formed spirally from the rear part to the front part. Further, inside the sleeve 29, the rear end communicates with the enlarged space 26 of the body body, and the front end thereof mixes with the mixing nozzle 51.
A resin flow channel 40 communicating with is formed in an annular shape outside the plunger sliding hole 31. 41 is the sleeve 2
It is an atmosphere opening port formed in 9.

The mixing nozzle 51 includes a nozzle main body 55 having a connection end 52 for screwing with the attachment 21 at the rear end, an injection port 53 formed at the front end, and a mixing head 56 inserted in the main body 55. Become. In the mixing head 56, the large diameter portion 57 and the small diameter portion 58 are alternately arranged,
It has a so-called rocket-shaped outer shape, and a groove 59 for enhancing mixing efficiency is formed on the outer surface of the large diameter portion 57. The gap between the outer surface of the mixing head 56 including the groove 59 and the inner surface of the nozzle body 55 is equal to that of the attachment 21.
And an injection flow path 60 communicating with the resin flow path 40. Further, the rear portion 61 of the mixing head 56 has a rear portion 6
1 Open / close ball holding member 3 on the outer peripheral surface and the front end of the sleeve 29
A communication channel 66 that connects the four is formed. The pressurizing chamber 32 of the sleeve and the injection flow channel 60 of the mixing nozzle 51 communicate with each other via the communication flow channel 66. Reference numeral 67 in the figure is a protrusion for restricting the back-and-forth movement of the open / close ball to a predetermined amount. The rear portion 61 of the mixing head is screwed onto the front end portion of the sleeve 29.

On the other hand, the colorant supplying device 71 may be any device having a discharge port 72 for the colorant. In this embodiment, the present inventors have the same one as previously shown in Japanese Patent Laid-Open No. 5-57750, namely, the injection valve 75 and the press-fitting device 8.
The one having 1 is used. The injection valve 75 reciprocates an actuating member (not shown) inserted in the discharge passage 76 by the drive motor M to open and close the pressure inlet 77 for the colorant or the like, and the air cylinder device 78 causes the valve rod 79. The discharge port 72 is opened and closed by reciprocating. The press-fitting device 81 has a cartridge 82 made of a flexible bag having a colorant or a cleaning agent inside in a storage container 83, and the rear portion of the cartridge 82 is pressed by compressed air blown from an air hole 83. The colorant or the cleaning agent in the cartridge 82 is press-fitted into the discharge passage 76 of the injection valve.

The plastic molding machine 10 having the colorant supply device thus constructed operates as follows. When the plasticization of the resin in the heating cylinder 11 is completed, the screw S is forcibly retracted to release the pressure of the heating cylinder 11.
So-called suck back is performed. As a result, the heating cylinder 11
Enlarged space 26 at the rear of the attachment 21 that communicates with the front end
2, the plunger 33 in the attachment 11 retracts, and as a result, the pressurizing chamber 32 in front of the plunger 33 also becomes negative pressure, near the outlet 36 to the mixing head. The existing open / close ball 35 is sucked toward the pressurizing chamber 32. In addition, since the molten resin remaining in the communication passage 66 of the mixing head still retains most of the pressure at the time of injection due to the high viscosity of the resin, the open / close ball 35 is strongly pressed toward the pressure chamber 32 side. And press it against the outlet 36 to ensure that the outlet 36 is closed.

Next, while the resin is being melted in the heating cylinder 11, the supply device 71 for the colorant or the like is operated,
The colorant is discharged from the discharge port 72 into the colorant channel 39 of the attachment 21. The discharged colorant is stored in the colorant channel 3
The pressure chamber 32 is reached through 9. At this time, since the outlet 36 to the mixing head is surely closed by the opening / closing ball 35 as described above, the coloring agent is mixed with the mixing head 5.
A predetermined amount is accumulated in the pressurizing chamber 32 without flowing to the 1 side.

Thereafter, the heating cylinder 1 is used to inject the molten resin.
When the screw S in 1 moves forward, the molten resin in the heating cylinder 11 flows into the resin flow passage 40 through the enlarged space 26 at the rear of the attachment 21 and further the injection flow passage 6 of the mixing head.
It reaches 0. At the same time, the expansion space 25 is pressed by the forward movement of the screw S and pushes the rear end of the plunger 33 to move the plunger 33 forward. The forward movement of the plunger 33 causes the pressurizing chamber 32 in front of the plunger 33 to move.
Is compressed and compressed, as shown in FIG.
Away from the outlet 36 to the mixing head,
The colorant therein passes through the communication passage 66 from the outlet 36 and reaches the injection passage 60 of the mixing nozzle. Then, the colorant and the molten resin join together in the injection channel 60 of the mixing nozzle, and as a mixed resin, the injection port 53 at the tip of the mixing nozzle.
Is ejected from. At this time, the mixed resin intermittently passes through the narrow groove 59 of the mixing head, so that the mixed resin is efficiently kneaded before reaching the injection port 53, and the colorant is prevented from floating on the resin surface. The resin injected from the injection port 53 has a marble pattern.

After that, the screw S retracts again as described above to plasticize the resin and prepare for the next injection.
In addition, at the time of cleaning, the storage container 83 of the press-fitting device 81 in the coloring agent supply device 71 is replaced with a container containing a cleaning agent.

[0019]

As shown and described above, according to the plastic molding machine of the present invention, since the coloring agent supply device is connected to the attachment provided at the tip of the heating cylinder, the coloring agent is discharged into the heating cylinder. Therefore, the coloring agent does not adhere to the inside of the heating cylinder and the screw. Therefore, the colorant adheres only to the attachment and the mixing nozzle ahead of the heating cylinder, the amount of the purge material required at the time of color change is small, and it is extremely economical, and the color change work is performed for a short time. And it can be done easily.

[Brief description of drawings]

FIG. 1 is a side view showing, in a partial cross section, the vicinity of an attachment of a plastic molding machine equipped with a coloring agent supply device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing the colorant inhaled in the molding machine.

FIG. 3 is an enlarged cross-sectional view showing a state where a colorant is mixed in the molding machine.

[Explanation of symbols]

 10 Plastic Molding Machine with Supply Device for Coloring Agent 11 Heating Cylinder 21 Attachment 23 Connection Part with Colorant or Cleaning Agent Supply Device 24 Connection Part with Heating Cylinder Tip Part 25 Connection Part with Mixing Nozzle 30 Pressurizing Part 32 Pressure chamber 33 Plunger 36 Outlet to mixing head 39 Colorant flow channel 40 Resin flow channel 51 Mixing nozzle 56 Mixing head 71 Coloring agent supply device 72 Discharge port of coloring agent supply device S screw

Claims (1)

[Claims] 1. A plastic molding machine equipped with a coloring agent or cleaning agent supply device, wherein one end is connected to the heating cylinder tip of the molding machine, the other end is connected to a mixing nozzle, and the side is colored. A resin flow path, which forms a connection with the cleaning agent supply device and guides the molten resin injected from the heating cylinder to the mixing nozzle, and is inserted so as to be movable back and forth according to the forward and backward movement of the screw in the heating cylinder. And a colorant that communicates between the pressure chamber and the connection between the colorant or the cleaning agent supply device, which is compressed or decompressed by the plunger and opens and closes the outlet to the mixing head. An attachment having a flow path is attached between the mixing nozzle and the tip of the heating cylinder,
A plastic molding machine equipped with a colorant or cleaning agent supply device, characterized in that a colorant or cleaning agent supply device is connected to a connection portion with the colorant or cleaning agent supply device.