JPH05185479A - Method and apparatus for manufacturing thermoplastic resin molded article - Google Patents

Abstract

PURPOSE:To obtain a molded article constituted of a polymer alloy and having a high impact resistance by a method wherein a polymer alloy molten body obtained by kneading by a double-screw extruder is injected directly into a mold and subjected to compression molding. CONSTITUTION:A polymer alloy molten body is formed by melting and kneading different kinds of thermoplastic resin by a double-screw extruder 1. This molten body is stored in an accumulator 7 through a connecting pipe 8. A prescribed amount of molten body is passed through a resin flow passage 8b through the intermediary of a three-way selector valve 6 and injected into a mold 15 provided in a press molding machine, through a temperature regulation nozzle 20. Subsequently, a top force is closed and compression molding is executed. It is preferable that a mold communication pipe 16 having resin flow passages 8c which communicate with the resin flow passage 8b and intersect each other perpendicularly is connected to a guide hole l4a of a bottom tool 14 and that pistons 17 and 19 for cleaning are provided for the resin flow passages 8b and 8c so as to discharge the molten body remaining in the flow passages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a thermoplastic resin molded article, and more particularly, to a molten polymer alloy melt obtained by mixing with a twin screw extruder.
The present invention relates to a new improvement for directly injecting into a mold to obtain a high-impact-resistant resin molded product made of a thermoplastic polymer alloy.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a resin molded product using this type of thermoplastic polymer alloy, generally, first,
A polymer alloy melt in which other thermoplastic resin components are made into fine particles and micro-dispersed in the thermoplastic resin component serving as a matrix using a twin-screw extruder, and a chemical bond is generated between the two components. The body was discharged from a die attached to the tip of a twin-screw extruder to granulate pellets. Then, the pellets were remelted using an injection molding machine and shaped into a desired shape to produce a resin molded product. Therefore, a granulation maker uses a twin-screw extruder for granulation, and a molding processing maker purchases these pellets by an injection molding machine and re-melts them to obtain a molded product. It was

[0003]

Since the conventional method for molding a resin molded article using a thermoplastic polymer alloy is configured as described above, the following problems exist. That is, when the pellets are remelted in the injection molding machine, before that, the dispersion state of the thermoplastic resin component in the pellets generated by the twin-screw extruder changes, and the physical properties of the resin molded product,
In particular, there is a serious problem that the impact resistance is lowered.

The present invention has been made to solve the above problems, and in particular, a molten polymer alloy melt obtained by mixing in a twin-screw extruder is directly put into a mold. It is an object of the present invention to provide a method and an apparatus for producing a thermoplastic resin molded article, which can be injected into and obtain a resin molded article made of a thermoplastic polymer alloy and having high impact resistance.

[0005]

The method for producing a thermoplastic resin molded article according to the present invention is to inject a polymer alloy melt produced by a twin-screw extruder directly into a mold,
It is a method of compression molding.

An apparatus for producing a thermoplastic resin molded article according to the present invention comprises a connecting pipe connected to an extrusion port of a twin-screw extruder and a mold connected to the connecting pipe and provided to be openable and closable. It is a composition.

More specifically, the connecting pipe is provided with an accumulator for storing the polymer alloy melt.

More specifically, a mold connecting pipe is provided between the connecting pipe and the mold, and a first cleaning piston and a second cleaning piston are provided in the connecting pipe and the mold connecting pipe. It is a configured structure.

[0009]

[Operation] In a method and an apparatus for producing a thermoplastic resin molded article according to the present invention, first, by melting and kneading a thermoplastic resin component in a temperature-controlled twin screw extruder,
It is possible to obtain a polymer alloy melt in which other components are finely dispersed in the matrix in the form of fine particles and a chemical bond is formed between the two components. Further, unnecessary volatile components can be volatilized from the vent port using a vacuum pump or the like. Further, the melt is stored in the accumulator via a connecting pipe attached to the tip of the twin-screw extruder. Further, after storing a predetermined amount in the accumulator, the unwanted melt is discharged to the outside via the three-way switching valve. A predetermined amount of melt is injected from the accumulator through the resin flow path into the mold provided in the press molding machine through the temperature control nozzle. The injected melt is compression molded into a predetermined shape by closing the upper mold, and the high temperature melt is cooled and solidified in the mold. Therefore, the polymer alloy melt produced in the twin-screw extruder is immediately metered and shaped,
Since it is directly molded without being remelted as in the conventional method, high impact resistance can be obtained. Since all the resin passages are temperature-controlled, the thermoplastic polymer alloy melt does not solidify during the process, and the fluidity thereof is maintained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the method and apparatus for producing a thermoplastic resin molded product according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an apparatus for producing a thermoplastic resin molded product according to the present invention.

A reference numeral 1 in the drawing is a twin-screw extruder, and different types of thermoplastic resin components A and B are mixed on the material inlet 2 of the twin-screw extruder 1. A supply device 3 for supplying the same is provided.

The tip portion 1a of the twin-screw extruder 1 is provided with a reactant supply port 4 and a vent port 5, and the extrusion port 1aA of the tip portion 1a has a three-way switching valve 6 and A connecting pipe 8 having an accumulator 7 is connected.

A press molding machine 9 is provided at the position of the tip portion 8a of the connecting pipe 8, and a press body 11 provided on a plurality of columns 10 of the press molding machine 9 is vertically movable. A mold 12 is provided. Base 13 of the press molding machine 9
A lower mold 14 corresponding to the upper mold 12 is provided on the upper side, and the molds 15 are constituted by the respective molds 12 and 14.

The guide hole 14a formed in the lower mold 14 is connected to a mold connecting pipe 16 having a resin flow passage 8c formed in communication with the resin flow passage 8b in the connecting pipe 8. The connecting pipes 8 and 16 are arranged orthogonal to each other.

The first cleaning piston 17 provided in the resin passage 8b of the connecting pipe 8 is slidably provided by the first cylinder 18 and is provided in the resin passage 8c of the mold connecting pipe 16. The second cleaning piston 19 provided is slidably provided by the second cylinder 20.

Next, a method of manufacturing the thermoplastic resin molded product according to the present invention having the above-mentioned structure will be described. First,
A screw type supply device 3 for supplying a thermoplastic resin component A such as nylon and a thermoplastic resin component B such as modified polyolefin.
Is fed into the material input port 2 of the twin-screw extruder 1 at a predetermined ratio. The supplied components A and B are melted and kneaded while being transferred forward by a biaxial screw (not shown), and the thermoplastic resin component A serving as a matrix is sheared into the sea-like state. , The thermoplastic resin component B is micro-dispersed in the form of particulate islands.

Next, the reactant is supplied from the reactant supply port 4 into the twin-screw extruder 1 by a liquid pump or the like (not shown), and is kneaded with the melt. Then, unnecessary volatile components are removed from the vent port 5 by a vacuum pump or the like (not shown).

The polymer alloy melt thus produced is continuously discharged from the twin-screw extruder 1.
It is stored in the accumulator 7 via the flexible connecting pipe 8. When a predetermined amount of this polymer alloy melt is stored in the accumulator 7, the unnecessary polymer alloy melt is discharged to the outside by the three-way switching valve 6.

Although not shown here, when a plurality of accumulators 7 are provided, an amount corresponding to the discharge amount of the twin-screw extruder 1 can be stored. The polymer alloy melt stored in the accumulator 7 is
Immediately after storage, the temperature control nozzle 20 is inserted into the cavity 15a of the mold 15 formed by the lower mold 14 and the upper mold 12 attached to the press molding machine 9 through the resin flow path 8b by the pushing operation of the piston 7a. Is ejected.

The temperature adjusting nozzle 20 is detachably attached to the lower mold 14 by a driving device (not shown). The polymer alloy melt injected into the cavity 15a is compression-molded by closing the lower mold 14 and the upper mold 12.
Although not shown in the drawing, the mold 15 has a structure capable of controlling the temperature.

The polymer alloy melt is cooled and solidified in the mold 15, and then the mold 15 is opened to be shaped into a desired shape and then taken out. It is also possible to inject and mold the polymer alloy melt under high pressure with the upper mold 12 and the lower mold 14 closed.

On the other hand, the polymer alloy melt remaining in the resin passage 8b is discharged outside the resin passage 8b by the first cleaning piston 17 and the second cleaning piston 19. As a result, it is possible to prevent the polymer alloy melt, which has deteriorated physical properties due to a change in its dispersion state (morphology) due to heat history during molding, from existing in the molded product. In addition, the operation of the first cleaning piston 17
As shown in the figure, if it moves from the left side to the right side and moves from the right side to the left side, all the polymer alloy melt remaining in the resin flow path 8b can be injected into the respective molds 12 and 14, so that it is effective without being discharged. It can be used.

A comparison test of the Izod impact value of the resin molded product directly molded by the method of the present invention with the above-mentioned apparatus and the resin molded product molded by the conventional method was found to be about 1.
The resin molded product of the present invention was able to obtain a higher value about 5 times.

The configuration of the connecting pipes 8 and 16 described above is not limited to the configuration of FIG. 1, but the length thereof is shortened so that the twin-screw extruder 1 and the die 15 are almost directly coupled. Even in this case, the same effect as the above can be obtained.

[0025]

Since the method and apparatus for producing a thermoplastic resin molded product according to the present invention are configured as described above, the following effects can be obtained. That is, by kneading and devolatilizing with a twin-screw extruder, a polymer alloy melt in which other thermoplastic resin components are micro-dispersed in the form of fine particles with the thermoplastic resin component as a matrix is subjected to the granulation process in the conventional manner. It can be stored in the accumulator immediately without passing, and a predetermined amount can be injected and compression molded. In addition, even if it is a material that is sensitive to heat, it has a structure to discharge the melt remaining in the resin flow path, so that the melt with changed physical properties will not be mixed in the molded product A molded product having is obtained. Furthermore, since the heat history only undergoes one melting and kneading operation, a molded product with little deterioration in physical properties can be obtained. Further, since it is a direct molding system without a granulation step, it is possible to reduce the granulation cost and achieve the cost reduction.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a method and apparatus for producing a thermoplastic resin molded article according to the present invention.

[Explanation of symbols]

 1 Twin screw extruder 1aA Extrusion port 7 Accumulator 8 Connection pipe 15 Mold 16 Mold connection pipe 17 First cleaning piston 19 Second cleaning piston

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[Procedure amendment]

[Submission date] December 14, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display area B29K 75:00

Claims (4)

[Claims] 1. A thermoplastic resin characterized in that a polymer alloy melt produced by kneading in a twin-screw extruder (1) is directly injected into a mold (15) and compression-molded. Molded article manufacturing method. 2. The extrusion port (1aA) of the twin-screw extruder (1).
The polymer alloy obtained by the twin-screw extruder (1) is provided with a connecting pipe (8) connected to the connecting pipe (8) and a mold (15) connected to the connecting pipe (8) and opened and closed. An apparatus for producing a thermoplastic resin molded article, characterized in that the melt is injected into the mold (15) through the connecting pipe (8). 3. The production of a thermoplastic resin molded product according to claim 2, wherein the connecting pipe (8) is provided with an accumulator (7) for storing the polymer alloy melt. apparatus. 4. A mold connecting pipe (16) is provided between the connecting pipe (8) and the mold (15), and inside the connecting pipe (8) and the mold connecting pipe (16), The apparatus for producing a thermoplastic resin molded product according to claim 2 or 3, further comprising a first cleaning piston (17) and a second cleaning piston (19).