JPH079491A - Thermosetting resin injection device - Google Patents

Abstract

PURPOSE:To provide a thermosetting resin injection device that can inject a plasticized material into a mold after a gas produced at the time of plasticizing the thermosetting resin material is sufficiently released. CONSTITUTION:A material supply means consists of a feed cylinder 32 for plasticizing a thermosetting resin material 50; a material introducing hopper 36 mounted on the feed cylinder for introducing the material; a feed screw 38 inserted in the feed cylinder for feeding the plasticized material forward; a die 42 for extruding the plasticized material, that has been fed forward by the feed screw, in a rope form; and a cutter device 116 mounted in the vicinity of the die for cutting the plasticized material into pellets 52. The top of the material supply means is disposed upward of a pellet supply opening part 17 provided in a heating cylinder 16 of an injection device. The aforesaid cut plasticized pellet material falls through the pellet supply opening part to be supplied into the heating cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin injection device, and more particularly to an injection device capable of efficiently releasing gas in a raw material. The thermosetting resin injection device of the present invention is also used for molding rubber in addition to the thermosetting resin.

[0002]

2. Description of the Related Art In a conventional thermosetting resin injection device, a resin raw material is put into a heating cylinder from a hopper provided in the heating cylinder, and the resin raw material is heated by a heating means such as a heater provided in the heating cylinder. While heating and plasticizing, it is sent forward by the screw in the heating cylinder, and finally the plastic raw material is injected into the mold from the nozzle at the tip of the heating cylinder to be cured.

By the way, the thermosetting resin raw material usually generates a gas when it is plasticized. Therefore, in order to obtain a good molded product, it was necessary to release the gas and then to inject it into a mold. However, in the conventional thermosetting resin injection device, the gas releasing means is not specially provided, and the gas generated from the raw material inside the heating cylinder is narrow between the inner peripheral surface of the heating cylinder and the outer peripheral surface of the screw. It only escaped to the rear of the heating cylinder through the gap. For this reason, sufficient degassing was not possible, and most of the gas was injected into the mold together with the plastic raw material from the nozzle while being confined in the plastic raw material. as a result,
The resulting molded article is prone to problems due to the gas,
Most of the defects were caused by the gas trapped in the resin.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above-mentioned points, and the gas generated at the time of plasticizing a thermosetting resin raw material is sufficiently released from the plastic raw material, It is intended to provide a thermosetting resin injection device capable of injecting a raw material into a mold.

[0005]

The present invention is a thermosetting resin injection device having a raw material supply means, wherein the raw material supply means includes a feed cylinder for plasticizing the thermosetting resin raw material, and The raw material feeding hopper attached to the feed cylinder for feeding the raw material, the feed screw inserted into the feed cylinder for feeding the plastic raw material forward, and the plastic raw material fed forward by the feed screw. It comprises a die provided at the tip of the feed cylinder for extruding in a string shape, and a cutter device provided in the vicinity of the die for cutting the string-like plastic material extruded from the die into pellets. The tip of the means is located above the pellet supply opening formed in the heating cylinder of the injection device, and is located inside the pellet supply opening. Plastic pellets material to fall after cutting, according to an injection device for the thermosetting resin, characterized in that it has to be supplied into the heating cylinder.

[0006]

The thermosetting resin injection device of the present invention operates as follows. First, the thermosetting resin raw material charged into the feed cylinder of the raw material supply means through the raw material feeding hopper is heated in the feed cylinder and is plasticized while being sent forward by the feed screw, and at the time of the plasticization, gas is generated. To occur. Some of the gas escapes rearward in the feed cylinder through the gap between the inner peripheral surface of the feed cylinder and the outer peripheral surface of the feed screw, and is discharged to the outside from the hopper for feeding the raw material, but most of it is a plastic raw material. It is trapped inside and is extruded as it is together with the plastic material from the mouthpiece at the tip of the feed cylinder in a string shape.

The string-shaped plastic raw material extruded from the die of the raw material supply means is cut into pellets in a plastic state by the cutter device. Then, the gas trapped in the plastic material until then is released to the outside from the surface and the cut surface of the pellet. Since there are two cut surfaces for each small pellet, the number of cut surfaces is innumerable from the viewpoint of the entire plastic material extruded from the die, and the gas is released very efficiently.

The plastic pellets, while releasing gas, fall into the pellet supply opening of the injection device located below the tip of the raw material supply means and are supplied as they are into the heating cylinder of the injection device. The plastic pellets supplied into the heating cylinder are further plasticized in the heating cylinder and kneaded by the main screw to become a continuous plastic raw material and sent to the front of the heating cylinder. During this further plasticization and kneading, a small amount of gas that was not released during the cutting and remained in the pellets is released from the pellets or the plastic material surface, and the heating cylinder inner peripheral surface of the injection device and the main screw outer peripheral surface. It escapes to the rear of the heating cylinder through the gap between them, and is discharged to the outside of the injection device through the pellet supply opening.

The plastic raw material sent to the tip of the heating cylinder after being sufficiently degassed in this way is injected into the mold by the advance of the main screw and hardens in the mold to contain the gas. It will be a good molded product.

[0010]

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 cross-sectional view showing a thermosetting resin injection device according to an embodiment of the present invention, and FIG. 2 is a 2-2 cross-sectional view thereof. The injection device 10 includes an injection device main body 11 and a raw material supply means 31. The main body 20 of the injection device main body 11 is inserted into a heating cylinder 16 having a nozzle 12 attached to the tip thereof, and a screw driving device (not shown) is connected to the rear part of the main screw 20.

The nozzle 12 is for introducing a plastic thermosetting resin raw material into a mold, and a known nozzle for a thermosetting resin injection device is used. The heating cylinder 16 is for heating plastic pellets to be described later to sufficiently perform plasticization. In the heating cylinder 16 of this embodiment, a jacket 15 for circulating the temperature control medium is provided on the peripheral wall portion as heating means. The rear part of the heating cylinder 16 has an upper surface opened to form a pellet supply opening 17, and the pellet supply opening 17 is provided with a hollow container 18 whose upper part is enlarged and whose upper and lower surfaces are opened.

The main screw 20 is for kneading, measuring, and injecting a plastic thermosetting resin raw material, and is used for an ordinary thermosetting resin injection device. The main screw 20 is rotated by a screw driving device (not shown) and is moved forward and backward.

The raw material supply means 31 is a feed cylinder 3
2, a raw material feeding hopper 36, a feed cru 38, a mouthpiece 42, and a cutter device 46. The feed cylinder 32 is for heating and thermosetting a thermosetting resin raw material, and a temperature control medium circulating jacket 33 is provided on the peripheral wall as a heating means thereof. The rear part of this feed cylinder is opened and a raw material feeding hopper 36 is attached.

The feed screw 38 is for kneading the thermosetting resin raw material fed into the feed cylinder 32 from the raw material feeding hopper 36 and sending it forward, and is rotatably inserted in the feed cylinder 32. ing. The rear portion of the feed screw 38 has a drive motor 4
The drive screw 40 is connected to the feed screw 38 so that the feed screw 38 is rotated. Drive motor 4
A geared motor is suitable as 0.

The mouthpiece 42 is for extruding the plastic material fed forward by the feed screw 38 into a string shape (a udon shape) and extruding it, and is made of a metal fitting having a predetermined number of through holes 43 formed therein. It is attached to the tip of the cylinder 32. Although the hole diameter of the through hole 43 of the die is appropriately determined, it is usually about 3 to 8 mm.

The cutter device 46 is for cutting the string-like plastic material extruded from the die 42 into pellets. In this embodiment, the cutter shaft 46 of the drive motor 47 has a propeller-shaped blade 49. Is installed. The drive motor 47 is preferably a geared motor whose rotation speed can be changed. In this cutter device 46, the blade 49 is substantially in sliding contact with the front surface 44 of the mouthpiece 42, and
It is attached to the upper part of the feed cylinder 32 near 2. The blade 49 is not limited to the illustrated double blade type.

In the raw material supply means 31, the front surface 44 of the die 42 is projected into the hollow container 18 of the injection apparatus main body 11 and is located above the pellet supply opening 17, so that the frame of the injection molding machine is provided. (Not shown).

The injection device 10 thus constructed operates as follows during injection molding. First, the thermosetting resin raw material 50 is put into the raw material feeding hopper 36 of the raw material supply means 31. As the thermosetting resin raw material 50, a rubber material can be used in addition to a pure thermosetting resin.

The thermosetting resin raw material 50 fed into the raw material feeding hopper 36 is introduced into the rear portion of the feed screw 38 in the feed cylinder 32, and the feed screw 3 is introduced.
The rotation of 8 feeds the inside of the feed cylinder 32 forward. At that time, the thermosetting resin raw material 50 is heated by the jacket 33 on the peripheral wall of the feed cylinder 32 and becomes the plastic raw material 51, which is sequentially sent to the tip of the feed cylinder 32. The heating temperature at this time is set to a temperature at which the thermosetting resin raw material used is plasticized. Further, a gas such as a decomposition gas is generated from the raw material 50 during the plasticization, and most of the gas is trapped in the plastic raw material 51. But,
A part of the gas is discharged from the surface of the plastic material 51 into the feed cylinder 32, and moves to the rear of the feed cylinder 32 through a slight gap between the outer peripheral surface of the feed screw 38 and the inner peripheral surface of the feed cylinder 32. It is discharged to the outside through the charging hopper 36.

The plastic raw material 51 sent to the tip of the feed cylinder 32 is pushed forward by the plastic raw material which is sequentially sent from the rear and is pushed out from the through hole 43 of the mouthpiece 42 in a string shape (udon shape). . The gas generated in the feed cylinder remains trapped in the string-shaped plastic material.

The plastic raw material extruded in the shape of a cord from the through hole 43 of the die 42 is cut into a predetermined length by the blade 49 of the cutter device 46 rotating on the front surface of the die 42 into a plastic pellet 52. As a result, most of the gas that has been trapped in the plastic raw material until now is lost in the pellet 52.
Emitted from the cut surface of.

The length of the pellet 52 can be set to a desired length by adjusting the rotation speed of the feed screw 38 and the rotation speed of the blade 49, but it is usually about 5 mm to 10 mm. Regarding the rotation speed of the feed screw 38, if the rotation speed is changed, the base 4
Since the amount of the plastic material extruded from 2 and the supply amount of the pellet 52 to the injection device main body 11 change, the injection amount is determined in consideration.

The pellet 52 formed by the cutting device 46 drops in the hollow container 18 while releasing gas, passes through the pellet supply opening 17 of the injection device main body 11 and reaches the rear part of the heating cylinder 16. Arrive And pellet 52
Is sent to the front inside the heating cylinder 16 by the rotation of the main screw 20 inside the heating cylinder 16, while being heated by the jacket 15 of the heating cylinder 16 to be further plasticized and kneaded to form a continuous plastic material. 53.

Further, the gas slightly remaining in the pellet 52 without being released at the time of cutting and the slight gas newly generated at the time of plasticizing in the heating cylinder 16 are in the heating cylinder 16 in the pellet 52 and the plastic raw material. When 53 is heated and advances, it escapes to the rear of the heating cylinder 16 through a slight gap between the outer peripheral surface of the main screw 20 and the inner peripheral surface of the heating cylinder 16,
6 is discharged to the outside of the heating cylinder 16 through the pellet supply opening 17 at the rear part. The amount of gas newly generated during plasticization in the heating cylinder 16 is small because most of the gas has already been generated in the feed cylinder 32 from the raw material.

After the degassed plastic raw material 53 is sent (measured) to the front of the heating cylinder 16 by a predetermined amount, the main screw 20 advances and the plastic raw material 53 is injected from the nozzle 12 into the mold. Then, it becomes a good molded product which is cured and has no defects due to the gas.

[0026]

As shown and described above, according to the present invention, the thermosetting resin is once plasticized to generate a gas, and the gas is released from the pellet surface and the cut surface during pellet formation, After that, since the pellets were supplied into the heating cylinder of the injection device, the raw material after degassing sufficiently could be injected into the mold, and the defects of the molded product due to the residual gas that had been generated conventionally could be eliminated. Of.

[Brief description of drawings]

FIG. 1 is a sectional view of an injection device according to an embodiment of the present invention.

FIG. 2 is a 2-2 sectional view thereof.

[Explanation of symbols]

 10 injection device 11 injection device main body 12 nozzle 16 heating cylinder 17 pellet supply opening 20 main screw 31 raw material supply means 32 feed cylinder 36 raw material input hopper 38 feed screw 42 cutter 46 cutter device 50 thermosetting resin raw material 51, 53 plastic material 52 pellets

Claims (1)

[Claims] 1. A thermosetting resin injection apparatus having a raw material supply means, wherein the raw material supply means includes a feed cylinder for plasticizing the thermosetting resin raw material and a feed cylinder for feeding the raw material. The attached material feeding hopper, the feed screw inserted into the feed cylinder for feeding the plastic raw material forward, and the feed cylinder for pushing the plastic raw material fed forward by the feed screw into a string shape. A die provided at the tip and a cutter device provided near the die for cutting the string-shaped plastic raw material extruded from the die into pellets, and the tip of the raw material supply means is an injection device. Located above the pellet supply opening formed in the heating cylinder, the cut plastic pellets in the pellet supply opening. Fee fall, thermosetting resin for injection apparatus being characterized in that so as to be supplied into the heating cylinder.