JP2613692B2 - Method and apparatus for producing thermoplastic resin molded article - Google Patents

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 product, and more particularly, to a method for producing a molten polymer alloy melt obtained by mixing with a twin screw extruder.
The present invention relates to a novel improvement for directly injecting into a mold to obtain a highly 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 kind of thermoplastic polymer alloy, generally, first,
Using a twin-screw extruder, a polymer alloy melt in which the other thermoplastic resin components are micro-dispersed into fine particles in the thermoplastic resin component serving as a matrix, and a chemical bond is created between both components. The body was discharged from a die attached to the tip of a twin-screw extruder to granulate pellets. Thereafter, the pellets were re-melted 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 maker purchases these pellets with an injection molding machine, obtains a molded product by re-melting and shaping. Was.

[0003]

The conventional method of molding a resin molded article using a thermoplastic polymer alloy has the following problems because it has been configured as described above. That is, when re-melting the pellets 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 impact resistance is reduced.

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

[0005]

According to the present invention, there is provided a method for producing a thermoplastic resin molded product, wherein a molten polymer alloy produced by a twin-screw extruder is directly injected into a mold.
This is a compression molding method.

An apparatus for producing a thermoplastic resin molded product according to the present invention includes 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 freely opened and closed. Configuration.

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

[0008] 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. Configuration.

[0009]

In the method and apparatus for producing a thermoplastic resin molded product according to the present invention, first, a thermoplastic resin component is melted and kneaded in a temperature-controlled twin-screw extruder.
It is possible to obtain a polymer alloy melt in which other components are finely dispersed in a matrix in a matrix and a chemical bond is generated between the two components. Unwanted volatiles can be devolatilized from the vent using a vacuum pump or the like. Further, the melt is stored in an accumulator via a connecting pipe attached to a tip of a twin-screw extruder. After a predetermined amount is stored in the accumulator, unnecessary melt is discharged to the outside through a three-way switching valve. A predetermined amount of the melt is injected from an accumulator through a resin flow path into a mold provided in a press molding machine through a 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 measured and shaped,
Since it is directly molded without being re-melted as in the conventional method, high impact resistance can be obtained. Since the temperature of all the resin passages is regulated, the thermoplastic polymer alloy melt does not solidify on the way, and its fluidity is maintained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and an apparatus for manufacturing a thermoplastic resin molded article according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an apparatus for manufacturing a thermoplastic resin molded product according to the present invention.

In the figure, reference numeral 1 denotes a twin-screw extruder, and different types of thermoplastic resin components A and B are mixed on a material input port 2 of the twin-screw extruder 1. There is provided a supply device 3 for supplying the raw material.

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

A press forming machine 9 is provided at the position of the distal end portion 8a of the connecting pipe 8, and a press body 11 provided on a plurality of columns 10 of the press forming machine 9 so as to be vertically movable is provided with an upper part. A mold 12 is provided. The base 13 of the press molding machine 9
On the upper side, a lower mold 14 corresponding to the upper mold 12 is provided, and a mold 15 is constituted by the molds 12 and 14.

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

A first cleaning piston 17 provided in the resin flow path 8b of the connection pipe 8 is slidably provided by a first cylinder 18, and is provided in the resin flow path 8c of the mold connection pipe 16. The provided second cleaning piston 19 is slidably provided by a second cylinder 20.

Next, a method for manufacturing a thermoplastic resin molded article according to the present invention in the above-described configuration will be described. First,
A screw type feeding device 3 for supplying a thermoplastic resin component A such as nylon and a thermoplastic resin component B such as modified polyolefin.
At a predetermined rate into the material inlet 2 of the twin-screw extruder 1. The supplied components A and B are melted and kneaded while being transported forward by a biaxial screw (not shown), and are placed in a sea-like state of the thermoplastic resin component A which becomes a matrix by shearing force. Then, the thermoplastic resin component B is micro-dispersed in a state like fine-particle islands.

Next, a reactant is supplied into the twin-screw extruder 1 from the reactant supply port 4 by a liquid pump or the like (not shown) and kneaded with the melt. Next, unnecessary volatile components are devolatilized 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 the polymer alloy melt is stored in the accumulator 7, 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 matching the discharge amount of the twin-screw extruder 1 can be stored. The polymer alloy melt stored in the accumulator 7 is
Immediately after the storage, the piston 7a pushes the resin through the resin flow path 8b and passes through the resin flow path 8b 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 via the temperature control nozzle 20 via the temperature control nozzle 20. Is injected.

The temperature control nozzle 20 is detachably provided on 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, the mold 15 has a structure capable of controlling the temperature.

After the polymer alloy melt is cooled and solidified in the mold 15, the mold 15 is opened, shaped into a desired shape, and taken out. It is also possible to inject and mold a 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 out of the resin passage 8b by the first cleaning piston 17 and the second cleaning piston 19. As a result, it is possible to prevent a polymer alloy melt having reduced physical properties due to a change in its dispersion state (morphology) due to a heat history during molding from being mixed in a molded article. Also, the operation of the first cleaning piston 17 is
As shown in the figure, if the resin alloy does not move from the left side to the right side but 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 each of the molds 12 and 14, so that it is effective without discharging. It can be used.

The results of a comparison experiment between the resin molded product directly molded by the method of the present invention using the above-described apparatus and the Izod impact value of the resin molded product molded by the conventional method were about 1.
The resin molded product of the present invention was able to obtain a higher value about 5 times.

The configuration of each of the connecting pipes 8 and 16 is not limited to the configuration shown in FIG. 1, but may be reduced in length so that the twin-screw extruder 1 and the mold 15 are almost directly connected. In this case, the same operation and effect as described above can be obtained.

[0025]

The method and apparatus for manufacturing a thermoplastic resin article according to the present invention are configured as described above, and the following effects can be obtained. In other words, the kneading and devolatilization by a twin-screw extruder are used to form a polymer alloy melt in which the thermoplastic resin component is used as a matrix and the other thermoplastic resin components are micro-dispersed in the form of fine particles. Without storing, it can be immediately stored in an accumulator, 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 that discharges the melt remaining in the resin flow path, so that the melt whose physical properties have changed does not coexist in the molded product, and has uniform physical properties. Is obtained. Furthermore, since the heat history is subjected to only one melting and kneading operation, it is possible to obtain a molded article with little deterioration in physical properties. Furthermore, since it is a direct molding system without a granulation process, the cost for granulation can be reduced and the cost can be reduced.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Twin screw extruder 1aA Extrusion port 7 Accumulator 8 Connecting pipe 15 Die 16 Die connecting pipe 17 First cleaning piston 19 Second cleaning piston

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29C 47/40 9349-4F B29C 47/40 // B29K 23:00 77:00

Claims (4)

(57) [Claims] A thermoplastic resin characterized in that a polymer alloy melt produced by kneading with a twin screw extruder (1) is directly injected into a mold (15) and compression-molded. Manufacturing method of molded article. 2. An extrusion port (1aA) of a twin screw extruder (1).
A connecting pipe (8) connected to the connecting pipe (8), and a mold (15) connected to the connecting pipe (8) and openably and closably provided, and the polymer alloy obtained by the twin-screw extruder (1) is provided. An apparatus for manufacturing a thermoplastic resin molded product, wherein a 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), 4. The apparatus for producing a thermoplastic resin article according to claim 2, wherein a first cleaning piston (17) and a second cleaning piston (19) are provided.