JPH0655386B2 - Flow injection molding method by twin injection molding machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flow injection molding method in which a molten resin is filled in a mold by flow and injection to perform molding.

[Conventional technology]

The following is known as a conventional flow injection molding method.

First, the method shown in FIG. 8 (Pattern I) will be described.

Using an injection molding machine equipped with one injection unit, the resin is plasticized by the injection unit with the nozzle hole closed, and the plasticization progresses and the molten resin is measured in the cylinder head part of the injection unit. , The back pressure causes the screw to retract.

Next, the nozzle hole is opened, the screw is rotated to a retracted position by increasing the screw back pressure, and the screw is rotated to perform a plasticizing operation (hereinafter referred to as "flow operation") to extrude the molten resin. A predetermined amount is filled in the mold which has been clamped (hereinafter, referred to as "flow molding"). Then, the flow operation is stopped, and the screw is moved forward (hereinafter, referred to as "injection operation"), and the mold is filled. Fill the remaining molten resin.

The method shown in FIG. 8 (Pattern II) is different from the method shown in FIG. 8 (Pattern I) in the steps described below.

The resin is plasticized by the injection unit, but when the plasticization progresses to a certain extent and molten resin begins to accumulate in the cylinder head portion, the nozzle hole is opened and the injection unit is caused to flow, and the above-mentioned FIG. A small amount of molten resin is extruded as compared with the method shown in (1) so that the molten resin is also stored in the cylinder head portion. That is, flow molding and plasticization are performed in parallel, and the molten resin is measured in the cylinder head portion.

After this flow molding is performed for a predetermined time, the injection unit is switched to the injection operation and the remaining molten resin is filled in the mold by injection.

[Problems to be Solved by the Invention]

In each of the above-mentioned conventional flow injection molding methods, one injection unit is made to flow or inject. Therefore, the flow rate of the molten resin to be flow molded by the flow operation can be adjusted only by controlling the rotation speed of the screw. There is. As a result, the extruding pressure of the molten resin first injected into the mold is insufficient, and when molding a thin molded product, the tip portion is not filled. Also, depending on the type of resin, it may solidify early or have poor fluidity, resulting in unstable quality of the molded product.
Furthermore, since the residence time of the resin in the cylinder is short, there is a problem that insufficient kneading occurs.

The present invention has been made in view of the problems of the above-described conventional technique, and it is possible to control the pressure of the molten resin filled in the mold even during the flow molding, and to fill the mold first. It is an object of the present invention to provide a flow injection molding method using a twin injection molding machine that does not cause a shortage of pressing pressure of molten resin or a shortage of kneading.

[Means for Solving the Problems]

In order to solve the above problems, the flow injection molding method by the twin injection molding machine of the present application comprises the steps described below.

No. 1 (FIG. 3) is provided with an injection head main body having one nozzle and two passages respectively connected to the nozzle, and the two passages are connected to separate injection units. In addition, a twin injection molding machine in which opening and closing means that can be independently opened and closed is provided in each of the two passages is used, the two passages are closed together, and the both injection units are plasticized to perform resin operation. After completion of plasticization, one of the two passages is opened, and one injection unit communicated with the opened passage is made to flow so that the molten resin is filled in the mold. Part filling, then the two passages are opened together, and the other remaining injection unit is made to perform an injection operation to perform injection in parallel with the continuous flow molding, and the remaining molten resin is left in the mold. To fill.

No. 2 (FIG. 4) is provided with an injection head main body having one nozzle and two passages respectively connected to the nozzle, and the two passages are connected to separate injection units. In addition, a twin injection molding machine in which opening and closing means that can be independently opened and closed is provided in each of the two passages is used, both of the passages are closed, and both of the injection units are plasticized. After plasticizing the resin, after the plasticization is completed, the two passages are opened together, and one injection unit is made to flow, and at the same time the other injection unit is made to operate, and the flow molding and the injection operation are performed in parallel for a predetermined time. Then, the mold is partially filled with the molten resin, and then only the passage communicating with the other injection unit is closed, and at the same time, the injection operation of the other injection unit is stopped to switch to the plasticizing operation. Previous Continuously by only one injection unit performs a predetermined time flow molding, After that, opens both the two passages when switching the injection operation to stop the plasticizing operation of the other injection unit at the same time,
The flow operation and the injection operation are performed in parallel to fill the remaining molten resin in the mold.

No. 3 (FIG. 6) is provided with an injection head main body having one nozzle and two passages respectively connected to the nozzle, and the two passages are connected to separate injection units. Further, a twin injection molding machine in which opening and closing means that can be independently opened and closed is provided in each of the two passages is used, and the two passages are both closed to plasticize both the injection units. Resin is plasticized, and after the plasticization is completed, the two passages are opened together, the plasticizing operation of both injection units is stopped, and the plasticizing operation of both the injection units is performed to perform the fluidizing operation for a predetermined time to perform the fluidizing in the mold. Part of the molten resin is filled, then the flow operation of both the injection units is stopped, and the injection operation is switched to both, and the remaining molten resin is filled in the mold.

Part 4 (FIG. 7) is provided with an injection head main body having one nozzle and two passages respectively connected to the nozzle, and the two passages are connected to separate injection units. Further, a twin injection molding machine in which opening and closing means that can be independently opened and closed is provided in each of the two passages is used, and the two passages are both closed to plasticize both the injection units. Resin is plasticized, and after the plasticization is completed, both of the above passages are opened, and one injection unit is made to perform an injection operation, while the other injection unit is made to flow operation, and injection and flow molding are performed in parallel for a predetermined time. Then, the molten resin is partially filled in the mold, and then the flow operation of the other injection unit is stopped and the injection operation is switched to the predetermined operation in parallel with the continuous injection by the one injection unit. Performed between injecting a molten resin into the mold partially filled, thereafter, is to fill the remaining solvent resin in the mold is performed repeatedly flowing operation and injection operation of the other injection unit.

Further, in each of the above methods, it is effective to carry out the holding pressure after filling the remaining molten resin in the mold.

[Action]

The two passages are closed together, and the separate injection units respectively connected to the two passages are plasticized to plasticize the resin with a double capacity. After completion of the plasticization, both passages are opened together, one of the two passages is opened, and one injection unit communicating with the opened passage is operated to flow, so that the molten resin is extruded. It is partially filled in the mold by flow molding. Among them, the two passages are opened together, and the remaining injection unit is injected to perform injection in parallel with the continuous flow molding to fill the remaining molten resin in the mold. A large amount of molten resin can be filled in the mold in a short time, and the flow rate and pressure of the molten resin can be controlled by controlling the speed and pressure of the injection unit performing the injection operation.

After the filling is completed, only one of the passages is closed, the flow operation of the one injection unit is stopped, and at the same time, the injection operation of the other injection unit is stopped and switched to the pressure holding operation to perform the pressure holding.

The above method is an example, and various molding methods can be performed by selecting a combination of operations of opening and closing two passages and plasticizing, injecting and ejecting two injection units.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

First, an example of a twin injection molding machine used for carrying out the method of the present invention will be described.

As shown in FIG. 1, in the injection head body 7, a nozzle portion 7b having a nozzle tip 1 screwed to a tip portion thereof is detachably fixed to a base portion 7a with a bolt or the like (not shown) so that it can be disassembled into a plurality of portions. It is configured. On the rear side of the base portion 7a, two pipe lines 13 and 14 are provided so as to project to both sides, and one pipe line 13 is a first pipe via a connecting portion 10a.
It is connected to the injection unit 15, and the other pipeline 14 is connected to the second injection unit 16 via the connection portion 10b.

The nozzle tip 1 is provided with a nozzle hole 1a, a conical hole that expands rearward from the nozzle hole 1a, an inner surface seal portion 1b and an inner surface seal portion 1b that are formed of a hole having the same diameter in the axial direction following the conical hole. A conical hole that expands rearward is formed. Inside the nozzle portion 7b, an outer torpedo 2 having a plurality of through holes 2a axially formed along the outer peripheral portion is fitted behind the nozzle tip 1 and has a cylindrical valve housing at its rear end. An outer passage 8 is formed between the outer peripheral surface of the valve housing 6 and the inner peripheral surface of the hole of the injection head body 7 including the nozzle portion 7b and the base portion 7a. Although the rear end of the outer passage 8 is closed in the axial direction, it is communicated with the pipe line 13, and the pipe line 13 is communicated with the first injection unit 15 via the connection portion 10a having the resin passage 11a. And the tip of the outer passage 8 is
A plurality of through holes 2a of the outer torpedo 2 communicate with the nozzle hole 1a.

The inner hole of the outer torpedo 2 has a large-diameter portion on the front half side and a small-diameter portion 2c on the rear half side. The large-diameter portion 2b has an intermediate large-diameter portion 3c of an inner torpedo 3 described later that slides in the axial direction. It is inserted freely.

On the other hand, the inner torpedo 3 has an intermediate large-diameter portion 3c in which a plurality of through holes 3d are formed in the axial direction along the outer peripheral portion thereof, and the inner passage 9 and the nozzle hole 1 are formed by these through holes 3d.
a is communicated with. A tip seal surface 3a is provided at the tip of the protruding portion protruding forward from the intermediate large diameter portion 3c, and a seal portion 3b is provided at the rear end peripheral surface of the protruding portion protruding rearward. Further, a small-diameter center shaft 5 inserted in the valve housing 6 is fixed to the rear end of the rearward projecting portion, and an inner passage 9 is formed between the outer peripheral surface thereof and the inner peripheral surface of the valve housing 6. The rear end of the inner passage 9 is closed in the axial direction but communicates with the pipe 14, and the pipe 14 has a connecting portion 10 having a resin passage 11b.
It communicates with the second injection unit 16 via b.

Further, the intermediate large-diameter portion 3c is longer than the distance between the tip of the outer torpedo 2 and the rear end of the inner surface seal portion 1b of the nozzle tip 1, and has a protruding length (the length of the protruding portion) of the tip seal surface 3a. Is equivalent to the nozzle hole 1a when the tip of the intermediate large-diameter portion 3 starts to be fitted into the inner seal surface 1b.
The length of the protrusion of the seal portion 3b is the intermediate length when the rear end of the seal portion 3b is separated from the tip portion of the small diameter portion 2c and the inner passage 9 is approximately half opened. The tip of the large diameter portion 2b is the inner surface seal portion 1 of the nozzle tip 1.
It is necessary that the length is such that it starts to fit into b.

On the other hand, the center shaft 5 is slidably supported in the axial direction at the rear end portion of the valve housing 6, but is hermetically supported, and the rear end projecting rearward from the valve housing 6 is reciprocating driving means via a connector 12. A certain hydraulic cylinder 4
It is connected to a piston rod 4b connected to the inner piston 4a. As a result, the piston 4 in the hydraulic cylinder 4
By supplying the hydraulic pressure to the rear chamber or the front chamber of a, respectively, the inner torpedo 3 via the center shaft 5
Move forward or backward, and move to any position between the most advanced position where the tip seal surface 3a closes the nozzle hole 1a and the most retracted position where the seal part 3b fits into the small diameter part 2c of the outer torpedo 2. And can be stopped.

The first injection unit 15 and the second injection unit 16
May be similar to a conventional in-line injection molding machine.
That is, the first injection unit 15 includes the first cylinder 15
b, and the first injection cylinder 17 fitted in the first b
The second injection unit 16 is composed of a first screw 15a which is driven by a piston 17a for injection and is rotated by a first plasticizing drive device for plasticization. The second injection unit 16 is fitted in a second cylinder 16b. It is composed of a second screw 16a which is driven for injection by the second piston 18a of the second injection cylinder 18 and is rotated by the second plasticizing drive device for plasticization.

As is apparent from the above description, in the twin injection molding machine, the inner torpedo 3 as the opening / closing means for the two passages is moved to an arbitrary position between the most advanced position and the most retracted position in the axial direction and stopped. Thus, the outer passage 8 and the inner passage 9, which are two passages, can be opened and closed freely.
The injection units 15 and 16 are configured so that their operation can be controlled independently.

The twin injection molding machine used for carrying out the invention of the present application is not limited to the above-mentioned one, and is provided with an injection head main body having one nozzle and two passages respectively connected to the nozzle. A separate injection unit may be connected to each of the passages, and a twin injection molding machine may be provided in which the two passages are individually provided with opening / closing means.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 3 shows the first embodiment and comprises the steps described below.

(A) As shown in FIG. 2 (A), the inner torpedo 3 is moved to the most advanced position and stopped, and the nozzle hole 1a is closed to close the outer passage 8 and the inner passage 9 together. The first and second injection units 15, 16 are plasticized to plasticize the resin.

(B) After the plasticization is completed, the inner torpedo 3 is moved to the position shown in FIG. 2E, that is, "the tip seal surface 3a of the inner torpedo 3 is separated from the rear end opening of the nozzle hole 1a by a predetermined distance. 1a is opened, and the tip of the intermediate large diameter portion 3c of the inner torpedo 3 is the inner surface seal portion 1 of the nozzle tip 1.
Although the outer passage 8 is closed by fitting into b, the rear end of the seal portion 3b of the inner torpedo 3 is separated from the tip of the small diameter portion 2c of the outer torpedo 2 by a predetermined distance to open the inner passage ". After moving and stopping, the second injection unit 16 is caused to flow to partially fill the mold with molten resin (hereinafter referred to as “flow molding”).

(C) Then, the inner torpedo 3 is located at the position shown in FIG. 2 (D), that is, "the intermediate large-diameter portion 3c of the inner torpedo 3".
Of the inner surface sealing portion 16 of the nozzle tip 1 is separated from the rear end of the inner surface sealing portion 16 by a predetermined distance, and the rear end of the sealing portion 3b is also separated from the rear end of the small diameter portion 2c of the outer torpedo 2 by a predetermined distance. Then, the first injection unit 15 is made to perform an injection operation to stop the remaining molten resin in parallel with the continuous flow molding by the flow operation of the second injection unit 16. Inject into mold.

(D) After that, in order to maintain the pressure, when the injection is completed, the inner torpedo is in the position shown in FIG. 2B, that is, "the seal portion 3b of the inner torpedo 3 is fitted into the small diameter portion 2c of the outer torpedo 2. Then, the inner passage 9 is closed, the intermediate large-diameter portion 3c of the inner torpedo 3 is completely retracted into the large-diameter portion 2b of the outer torpedo 2, and is moved to a position where the outer passage 8 is opened. At the same time when the flow operation of the unit 16 is stopped, the first injection unit 15 is switched to the pressure holding operation to hold the pressure.

Further, as a modification of the first embodiment, the opening / closing of the outer passage 8 and the first injection unit 15, and the opening / closing of the inner passage 9 and the second injection unit 16 may be operated in reverse. This case will be described below. However, in the case of the method of “No. 2” and subsequent steps, which will be described later, the same operation can be performed in the opposite manner.
In the description of the method after "No. 2", the description will be omitted.

(1) Perform step (a) above. (2) Position the inner torpedo 3 at the position shown in FIG. 2 (B) when the plasticization of the resin is completed, that is, the inner torpedo 3
Of the outer torpedo 2 is inserted into the small diameter portion 2c of the outer torpedo 2 to close the inner passage 9, and the intermediate large diameter portion 3c of the inner torpedo 3 is completely drawn into the large diameter portion 2b of the outer torpedo 2 to open the outer passage. Move to the opened position and stop, then
The injection unit is made to flow and the mold is partially filled with molten resin by flow molding.

(3) After that, the inner torpedo 3 is moved to a position where both the outer passage 8 and the inner passage 9 shown in FIG. 2 (D) are opened and stopped, and the injection operation of the second injection unit 16 is performed. (1) Injection is performed in parallel with the flow molding by the flow operation of the injection unit 15 to fill the remaining molten resin in the mold.

(4) After that, in order to perform holding pressure, when the injection by the step (3) is completed, the inner torpedo 3 is shown in FIG. 2 (E), the outer passage 9 is closed, but the inner passage is closed. Moves to the opened position and stops, stopping the flow operation of the first injection unit 15 and at the same time stopping the injection operation of the second injection unit 16 and switching to the pressure holding operation to perform the pressure holding.

FIG. 4 shows a second embodiment, which comprises the steps described below.

(1) The step (a) of the first embodiment is performed.

(2) When the plasticization is completed, the inner torpedo 3 is moved to the position shown in FIG. 2 (D) and stopped, both the outer passage 8 and the inner passage 9 are opened, and the first injection unit 15 is operated to inject. At the same time, the second injection unit 16 is caused to flow to perform injection and flow molding in parallel to partially fill the mold with the molten resin.

(3) After that, the inner torpedo 3 is moved to the position shown in FIG. 2 (E) and stopped, and the outer passage 8 is closed, but the inner passage 9 is opened, and the injection operation of the first injection unit 15 is stopped and plasticized. Then, the second injection unit 16 is continuously made to flow to perform flow molding for a predetermined time.

(4) Then, the inner torpedo 3 is again moved to the position shown in FIG. 2 (D) and stopped, both the outer passage 8 and the inner passage 9 are opened, and the first injection unit 15 is operated to inject the second Injection is performed in parallel with the flow molding by the flow operation of the injection unit 16 to fill the remaining molten resin in the mold.

(5) After that, in order to maintain the pressure, after the filling is completed, the inner torpedo is moved to the position shown in FIG. 2 (B) and stopped, the outer passage 8 is opened, the inner passage 9 is closed, and the second injection unit 1 is closed.
At the same time as stopping the flow operation of No. 6, the first injection unit 15
Is switched to the pressure-holding operation to hold the pressure.

FIG. 5 shows a third embodiment, which comprises the steps described below.

(1) The step (a) of the first embodiment is performed.

(2) After the plasticization is completed, the inner torpedo 3 is moved to the position shown in FIG. 2 (D) and stopped, both the outer passage 8 and the inner passage are opened, and the first injection unit 15 is made to perform the injection operation and at the same time. (2) The injection unit 16 is made to flow, and the molten resin is partially filled in the mold by injection and flow molding.

(3) After that, the inner torpedo 3 is moved to the position shown in FIG. 2 (E) and stopped, the outer passage 8 is closed and the inner passage 9 is opened, and the injection operation of the first injection unit 15 is stopped to plasticize. The operation is switched to, at the same time, the flow operation of the second injection unit 16 is stopped and switched to the injection operation, and injection is performed for a predetermined time.

(4) Then, the inner torpedo 3 is moved to the position shown in FIG. 2 (D) and stopped, both the outer passage 8 and the inner passage 9 are opened, and the first injection unit 15 is made to perform the injection operation again and at the same time The injection operation of the injection unit is stopped and switched to the flow operation, and injection and flow molding are performed in parallel to fill the remaining molten resin in the mold.

(5) After that, in order to maintain the pressure, after the filling is completed, the inner torpedo 3 is moved to the position shown in FIG. 2 (B) and stopped, the outer passage 8 is opened and the inner passage 9 is closed, and the second injection unit is closed. 1
At the same time as stopping the flow operation of No. 6, the first injection unit 15
The injection operation is stopped and the operation is switched to the pressure-holding operation to hold the pressure.

FIG. 6 shows a fourth embodiment, which comprises the steps described below.

(1) The step (a) of the first embodiment is performed.

(2) After the plasticization is completed, the inner torpedo 3 is moved to the position shown in FIG. 2 (D) and stopped, the outer passage 8 and the inner passage 9 are opened together, and the first and second injection units 15, 1
6 are made to flow at the same time to perform flow molding for a predetermined time,
Part of the molten resin is filled in the mold.

(3) After that, the flow operation of the first and second injection units 15 and 16 is stopped and switched to the injection operation, and injection is performed by both injection units 15 and 16 to fill the remaining molten resin in the mold.

(4) After that, in order to maintain the pressure, after the filling is completed, the inner torpedo 3 is moved to the position shown in FIG. 2 (B) and stopped, the outer passage 8 is opened and the inner passage 9 is closed, and the second injection unit is closed. 1
At the same time as stopping the injection operation of No. 6, the first injection unit 15
The injection operation is stopped and the operation is switched to the pressure-holding operation to hold the pressure.

In this embodiment, the flow rate is doubled in both flow molding and injection.

FIG. 7 shows a fifth embodiment, which comprises steps as described below.

(1) The step (a) of the first embodiment is performed.

(2) After the plasticization is completed, the inner torpedo 3 is moved to the position shown in FIG. 2 (D) and stopped, both the outer passage 8 and the inner passage 9 are opened, and the first injection unit 15 is ejected at the same time. The second injection unit 16 is caused to flow, and injection and flow molding are performed in parallel for a predetermined time to partially fill the mold with the molten resin.

(3) Then, the flow operation of the second injection unit 16 is stopped and switched to the injection operation, and the first injection unit 1 continues.
In parallel with the injection operation of No. 5, the injection by both injection units is performed for a predetermined time to further partially fill the mold with the molten resin.

(4) After the lapse of a predetermined time, only the second injection unit 16 stops the injection operation and switches to the flow operation, and the flow molding is performed for a predetermined time in parallel with the continuous injection operation of the first injection unit 15.

(5) When the predetermined time has elapsed, the flow operation of the second injection unit 16 is stopped and switched to the injection operation, and the injection operation is performed for a predetermined time in parallel with the continuous injection operation of the first injection unit 15 and the inside of the mold is completed. To the rest of the molten resin.

(6) After that, in order to maintain the pressure, after the filling is completed, move the inner torpedo to the position shown in FIG. 2 (B) and stop it.
The outer passage 8 is opened, the inner passage 9 is closed, and the injection operation of the second injection unit 16 is stopped. At the same time, the injection operation of the first injection unit 15 is stopped and the pressure holding operation is switched to the pressure holding operation.

In this embodiment, compared with the fourth embodiment, the molten resin can be continuously filled in the mold, and the quality of the molded product is improved.

The steps (4) and (5) of this example may be repeated twice or more.

Further, in FIGS. 3 to 6, although the flow or injection operation is started immediately after the completion of plasticization in the first and second injection units, the next operation may be started after a certain time interval. . Alternatively, although the injection operation is stopped at intervals after the flow operation is stopped in the step immediately before the pressure holding (FIG. 3), the two operations may be stopped.

〔The invention's effect〕

Since the invention of the present application is configured as described above, it has the following effects.

(1) Since a relatively small injection unit has double the plasticizing ability, a large amount of molten resin can be filled in the mold accordingly.

(2) Even when one injection unit is fluidized to perform flow molding, the other injection unit can be simultaneously injected to perform injection operation, and the injection pressure can be controlled to control molding conditions. The range of products to be molded is expanded much more than conventional products.

(3) Since the filling of the molten resin into the mold does not cause a blank time between the filling by flow molding and the filling by injection,
Since the molten resin can be continuously filled in the mold without breaking, hesitation marks and the like do not occur in the molded product.

(4) Since the injection pressure and the flow rate can be controlled by one of the injection units without interruption, the molding conditions can be controlled freely and the quality of the molded product can be stabilized.

(5) By performing the flow operation, the injection amount for the flow operation of the injection capacity + α is added to only one injection unit. If you let both units perform a floating action, it will double.

(6) By holding pressure, sink marks and the like can be prevented, and the quality of molded products is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part showing an example of a twin injection molding machine used for carrying out the method of the present invention, and FIGS. 2 (A) to 2 (E).
3A and 3B respectively show opening and closing operation positions of the outer passage and the inner passage in the twin injection molding machine shown in FIG. 1, FIG. 7A is a sectional view of a main part showing a state in which both the outer passage and the inner passage are closed, and FIG. Sectional drawing which shows the state which opened the passage and closed the inside passage, (C) is sectional drawing which shows the state which closed the inside passage at the same time as making the opening degree of the outside passage half open, (D)
Is a sectional view of an essential part showing a state in which both the outer passage and the inner passage are opened, (E) is a sectional view of an essential part showing a state in which the outer passage is closed and the inner passage is opened, and FIGS. FIGS. 8A and 8B are explanatory views showing combinations of operation types and timings of the first injection unit and the second injection unit in the embodiments to the fifth embodiments, and FIG. 8 is an explanatory view showing patterns in the conventional single injection unit. 1 ... Nozzle tip, 1a ... Nozzle hole, 2 ... Outer torpedo, 2a ... Through hole, 2b ... Large diameter part, 2c ... Small diameter part, 3 ... Inner torpedo, 3a ... Tip seal part, 3b ... seal part, 3c ... large diameter part, 3d ... through hole, 4 ... hydraulic cylinder, 4a ... piston, 4b ... piston rod, 5 ... center shaft, 6 ... valve housing, 7 ...... Injection head, 8 ...... Outer passage, 9 ...... Inner passage, 10a, 10b ...... Connecting part, 11a, 11b ...... Resin passage, 12 ...... Connector, 13,14 ...... Pipe, 15 ...... 1 injection unit, 15a ... first screw, 15b ... first cylinder, 16a ... second screw, 16b ... second cylinder, 17 ... first injection cylinder, 17a ... first piston, 18 ... Second injection cylinder 18a ...... second piston, 19 ...... first plasticizing driving device, 20 ...... second plasticizing drive.

Claims (5)

[Claims] 1. An injection head main body having one nozzle and two passages respectively communicating with the nozzle, wherein separate injection units are communicated with the two passages, respectively. A twin injection molding machine in which opening and closing means that can be opened and closed independently is provided in each of the two passages is used. The two passages are closed together and the both injection units are plasticized to plasticize the resin. After the completion of plasticization, one of the two passages is opened, and one injection unit communicating with the opened passage is made to flow to perform a flow molding to partially melt the molten resin in the mold. After the filling, and then the two passages are opened together, the remaining other injection unit is operated to perform an injection operation in parallel with the continuous flow molding to perform the injection, and the remaining molten resin is injected into the mold. Characterized by filling Flow injection molding method by twin injection molding machine. 2. An injection head main body having one nozzle and two passages respectively communicating with the nozzle, wherein separate injection units are communicated with the two passages, respectively. A twin injection molding machine in which opening and closing means that can be opened and closed independently is provided in each of the two passages is used, both of the passages are closed, and both of the injection units are plasticized to plasticize the resin. After the plasticization is completed, the two passages are opened together, and one injection unit is made to flow, and at the same time the other injection unit is made to perform an injection operation to perform fluid molding and injection in parallel for a predetermined period of time. Part of the mold is filled with molten resin, and then only the passage communicating with the other injection unit is closed, and at the same time, the injection operation of the other injection unit is stopped and switched to the plasticizing operation. Out continuously only by the unit performs a predetermined time flow molding, After that, opens both the two passages when switching the injection operation to stop the plasticizing operation of the other injection unit at the same time,
A flow injection molding method using a twin injection molding machine, characterized in that flow molding and injection are performed in parallel to fill the remaining molten resin in the mold. 3. An injection head main body having one nozzle and two passages respectively connected to the nozzle, wherein separate injection units are connected to the two passages, respectively. A twin injection molding machine in which opening and closing means that can be opened and closed independently is provided in each of the two passages is used. The two passages are closed together, and both injection units are plasticized so that the resin is plasticized. After the completion of plasticization, the two passages are opened together, the plasticizing operation of both injection units is stopped, the plasticizing operations of both the injection units are stopped, and the both fluidizing operations are performed to perform the fluidized molding for a predetermined time so that the molten resin is filled in the mold. Partial filling, and then stopping the flow operation of both the injection units and switching to the injection operation together to fill the remaining molten resin in the mold, the flow injection molding method using a twin injection molding machine. 4. An injection head main body having one nozzle and two passages respectively communicating with the nozzle, wherein separate injection units are communicated with the two passages, respectively. A twin injection molding machine in which opening and closing means that can be independently opened and closed is provided in each of the two passages is used, both of the passages are closed, and both injection units are plasticized to plasticize the resin. After completion of plasticization, both the above-mentioned passages are opened, one injection unit is made to perform an injection operation, and at the same time the other injection unit is made to flow operation, and injection and flow molding are performed in parallel for a predetermined time and the mold Part of the inside is filled with molten resin, and then the flow operation of the other injection unit is stopped to switch to the injection operation, and the injection is continued for a predetermined time in parallel with the injection by the one injection unit that continues. Twin injection molding, characterized in that the molten resin is partially filled in the mold, and thereafter, the flow operation and the injection operation of the other injection unit are repeated to fill the remaining molten resin in the mold. Injection molding method by machine. 5. After filling the remaining molten resin in a mold,
The flow injection molding method using a twin injection molding machine according to claim 1, 2, 3, or 4, wherein holding pressure is performed.