KR100360420B1 - Gas supplier for making foamed plastic - Google Patents

Abstract

The gas supply apparatus for manufacturing a foamed plastic according to the present invention receives a gas compression means for receiving an inert gas forming a bubble in the plastic from the gas storage means and compresses it to a high pressure, and receives the high pressure gas compressed by the gas compression means A receiving means for storing at a constant pressure, a gas supply means for supplying a predetermined amount continuously or intermittently to the foamed plastic molding machine after temporarily storing the high pressure gas delivered from the receiving means, between the gas supply means and the plastic molding machine A shutoff valve installed to control the supply of gas; In the gas supply device for producing a foamed plastic comprising a control unit for controlling the operation of the gas compression means and the shutoff valve,

The gas supply means adjusts the amount of gas supplied so that the gas is mixed with the plastic contained in the cylinder of the plastic molding machine and supplies the gas to the plastic molding machine, thereby continuously or intermittently supplying a certain amount of gas into the plastic molding apparatus. The present invention relates to a gas supply apparatus for producing foamed plastics, which allows mass production of foamed plastics with sufficient mechanical strength by allowing mixing with molten plastics.

Description

Gas supplier for making foamed plastics {Gas supplier for making foamed plastic}

The present invention relates to a technology for supplying a certain amount of gas to a plastic molding machine in order to produce a foamed plastic with uniformly distributed bubbles therein, in particular plastic molding continuously or intermittently the amount of gas determined according to the weight of the molded article The present invention relates to a gas supply device for producing foamed plastics supplied to a machine.

In general, technology is advancing towards reducing the weight of products so that more work can be done with the same effort. Therefore, existing steel products are made of light non-ferrous metals such as aluminum, and research is being conducted to use light materials such as plastics again. In particular, plastics have a wide variety of uses due to their ease of molding, and are used in almost all industrial fields.

Techniques for making plastics into desired shapes include methods such as extrusion, injection molding, reaction injection molding and thermoforming. The above plastic molding technology manufactures various molded articles by melting plastic pellets, that is, pellets, which are mostly made in a chemical factory using electric heat and mechanical friction, and then pushing them into a mold having a desired shape by applying force.

However, since plastics have a very high proportion of materials compared to other materials, foaming technology has been developed by efforts to further reduce the weight of plastic products as well as material costs. Foaming technology is a technology that creates a lot of fine-sized bubbles in plastic products, and mixes chemical or physical foams with pellets and heats the foam to vaporize the foams inside the product. . When bubbles are formed, bubbles occupy a large part of the product, which can greatly reduce material costs, reduce the weight of the product, and provide thermal insulation performance due to bubbles.

Foaming technology has been beneficial in many ways, but partly due to the inadequate mixing of foaming materials in plastics and the reduction in mechanical strength such as impact strength and toughness due to the small number of large bubbles produced. It has a disadvantage that can not be used in structures that require mechanical strength by causing. In addition, foaming materials such as pentane and freon, which are used for foaming, are harmful to the environment, and thus the use of the foaming materials is limited. Therefore, foaming technology using gas has been developed to overcome this disadvantage.

Gas foaming technology supplies gas to the molten plastic and rotates the screw inside the cylinder to push out the plastic / gas solution to induce a pressure difference so that the gas is foamed by the pressure difference inside the plastic / gas solution. will be. In the case of the foaming technology using gas, fine bubbles are uniformly distributed throughout the product, and the bubbles have a diameter of about tens of micrometers and the number of bubbles is 10 ⁹ or more per unit volume (cm 3). Can be prevented from lowering mechanical strength, which is indicated as a limitation of the foaming technique.

However, a device for supplying gas into the plastic molding machine to be mixed with plastic has not been developed separately. In gas forming technology, a technology for creating an empty space by injecting gas into a plastic solution injected into a mold has been developed. It is used.

The present invention has been made to solve the above-mentioned problems of the prior art, and in order to form an extremely fine bubble in the interior of the plastic, a certain amount of gas continuously to be mixed with the molten plastic in the cylinder of the plastic molding machine Another object is to provide a gas supply device for producing expanded plastic that can be intermittently supplied.

1 is a block diagram showing a gas supply device for producing a foamed plastic according to the present invention,

Figure 2 is a view showing a pump-type container of the gas supply means of the main component of the present invention, Figure 2a is a fixed capacity container, Figure 2b is a variable displacement container,

Figure 3 is a view showing a tubular vessel of the gas supply means of the main component of the present invention, Figure 3a is a container for a small and medium plastic molding machine, Figure 3b is a container for a large plastic molding machine.

<Explanation of symbols for the main parts of the drawings>

10 gas supply device 11 gas booster

12 main receiver 13 regulator valve

14: sub receiver 15: gas supply means

20: gas cylinder 21: pressure sensor

30: plastic molding machine

In order to achieve the above object, by receiving the inert gas to form a bubble in the plastic according to the present invention from the gas storage means to compress the gas at high pressure, and receiving the high pressure gas compressed by the gas compression means A receiving means for storing at a constant pressure, a gas supply means for supplying a predetermined amount continuously or intermittently to the foamed plastic molding machine after temporarily storing the high pressure gas delivered from the receiving means, between the gas supply means and the plastic molding machine A shutoff valve installed to control the supply of gas; In the gas supply device for manufacturing a foamed plastic comprising a control unit for controlling the operation of the gas compression means and the shut-off valve, The gas supply means for adjusting the amount of gas supplied so that the gas is mixed with the plastic contained in the cylinder of the plastic molding machine It characterized in that the supply to the plastic molding machine.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The gas supply device for manufacturing a foamed plastic of the present invention, as shown in Figure 1 is a gas cylinder 20, which stores an inert gas to form a fine bubble inside the plastic, and the inert gas supplied from the gas cylinder 20 A gas booster 11 for compressing at a high pressure, a main receiver 12 for storing a high pressure gas compressed by the gas booster 11 so as to have a uniform pressure, and a regulator valve 13 'for adjusting a flow rate of gas. Sub receiver 14 for receiving a high pressure gas stored in the main receiver 12 through a) to provide a more stable gas supply, and the high pressure gas delivered from the sub receiver 14 is temporarily stored to manufacture a foamed plastic Gas supply means 15 for supplying a predetermined amount continuously or intermittently to the plastic molding machine 30 to adjust the amount of gas supplied using various variables, A regulator valve 13 installed between the sub-receiver 14 and the gas supply means 15 so that the high pressure gas is stored in the gas supply means 15 at a desired pressure, and the gas supply means 15 and A shut-off valve 16 disposed between the plastic molding machines 30 to control the supply of gas, and a control unit 17 for controlling the operation of the gas booster 11 and the shut-off valve 16. Bubbles formed by the inert gas are formed of fine bubbles having a diameter of about several tens of micrometers and a number of 10 ⁹ or more per unit volume (1 cm 3).

The gas booster 11 may be configured in multiple stages to compress the gas to a sufficient pressure within a predetermined time even when the internal pressure of the gas cylinder 20 is low, and the gas cylinder 20 detects an internal pressure. When the pressure sensor 21 is installed so that the gas pressure drops below a certain level, the controller 17 blocks the operation of the gas booster 11. In addition, the main receiver 12 and the sub-receiver 14 are provided with a safety valve 18 for releasing gas when a specified pressure is exceeded.

The gas supply means 15 is provided with a temperature control device 19 to adjust the internal temperature to a desired value, the gas supply means 15 to supply a certain amount of high pressure gas of a prescribed pressure to the plastic molding machine It is formed in various forms in order to.

2 shows a pump type container for supplying a high pressure gas to the plastic molding machine 30 by using a piston 15 ', and FIG. 2A shows a capacity fixed container with a constant volume of the container, and FIG. 2B Shows a variable displacement container capable of changing the volume of the container by moving the piston 15 'back and forth. In addition, Fig. 3 shows a tubular vessel for adjusting the gas supply amount by using the gap between the valves 15c and 15d and the diameter of the pipe, and the vessel of Fig. 3a is a small and medium machine having a relatively small amount of high pressure gas required. 3b is used in a large machine requiring a relatively high amount of high pressure gas, and has a separate gas reservoir 15e capable of storing the high pressure gas.

The gas supply apparatus for producing a foamed plastic according to the present invention configured as described above supplies a high-pressure inert gas to the plastic manufacturing apparatus continuously or intermittently to produce a foamed plastic in which fine bubbles are uniformly distributed.

An inert gas such as carbon dioxide (CO ₂ ) or nitrogen (N ₂ ) is stored in the gas cylinder 20, and the gas booster 11 of the gas supply device 10 compresses the inert gas transmitted from the gas cylinder 20. High pressure gas, ie supercritical state. At this time, considering that the pressure of the inert gas stored in the gas cylinder 20 decreases with time, it can be seen that the time for the gas booster 11 to compress the inert gas to a high pressure gradually increases. Therefore, the gas booster 11 must be installed in multiple stages so that the inert gas can be compressed to a supercritical pressure at all times within a predetermined time. In addition, the pressure sensor 21 installed in the gas cylinder 20 detects that the gas pressure inside the gas cylinder 20 falls below a prescribed pressure, thereby causing the controller 17 to stop the operation of the gas booster 11. To do that.

The high pressure inert gas changed into the supercritical state by the gas booster 11 is temporarily stored in the main receiver 12, and the high pressure inert gas is changed to a uniform pressure in the main receiver 12. Thereafter, the high pressure inert gas of the main receiver 12 is supplied to the sub receiver 14 through the regulator valve 13 '. The regulator valve 13 'adjusts the flow rate of gas so that a high pressure inert gas is supplied at a constant pressure. At this time, the main receiver 12 has a larger volume and maintains a higher pressure than the sub receiver 14 so as to stably supply a high pressure inert gas to the sub receiver 14. If the internal pressure of the main receiver 12 and the sub-receiver 14 rises above the specified pressure, there is a risk of explosion. Safety is achieved by releasing the gas.

The sub receiver 14 sends a gas to the gas supply means 15 so that the gas supply means 15 can supply a predetermined amount of the high pressure inert gas to the plastic molding machine 30. At this time, the temperature control device 19 installed in the gas supply means 15 to maintain a constant temperature of the gas supply means 15, the final pressure of the high-pressure inert gas supplied to the plastic molding machine 30 is It is regulated by a regulator valve 13 provided between the sub receiver 14 and the gas supply means 15. The shutoff valve 16 installed between the gas supply means 15 and the plastic molding machine 30 is automatically opened when the high pressure inert gas is discharged from the gas supply means 15 and manual operation is also possible.

Here, the gas storage container 15 may be classified into a pump type and a pipe type according to a gas storage and supply method. In the pump type, as shown in FIG. 2, after filling the inert gas into the cylinder, the inlet 15a is blocked, and the piston 15 'is advanced while the outlet 15b is opened, and the high pressure inert gas is passed to the plastic molding machine 30. The high pressure inert gas is provided between the inlet valve 15c and the outlet valve 15d by installing valves 15c and 15d on both sides of the pipe in which the volume is constant and maintained at a desired temperature. After storing the high pressure inert gas is supplied to the plastic molding machine 30 by the pressure of the gas by opening the outlet valve (15d).

The pump-type gas supply means blocks the inlet 15a and the outlet 15b after the high-pressure inert gas of the sub receiver 14 is filled inside through the inlet 15a of the cylinder at the required pressure by the regulator valve 13. When the piston 15 'is advanced by using a mechanical force or hydraulic pressure in the open state, the high pressure inert gas in the cylinder is supplied into the plastic molding machine 30. The gas supply means 15 shown in FIG. 2A is a fixed capacity container, and the internal volume of the cylinder is constant, and the gas supply means 15 shown in FIG. 2B is a capacity variable container, which moves along the front and rear of the piston 15 '. The internal volume of the cylinder is changed. Since the temperature of the gas supply means 15 is kept constant by the temperature regulating device 19, the amount of gas supplied to the plastic molding machine 30 is determined by the volume of the cylinder and the pressure of the gas. Therefore, when the volume of the cylinder is constant, the pressure, which is a variable that can determine the amount of gas, has only one value. When the volume of the cylinder is variable, the pressure, which is a variable that can control the amount of gas, varies depending on the volume. It becomes wider. However, in the case of using the pump-type gas supply means there is a disadvantage that the cycle in the plastic molding machine may be unstable as the pressure increases.

In the piping type gas supply means, valves 15c and 15d are provided on both sides of the pipe in which the volume is constant and maintained at a desired temperature, and the inlet valve 15c is opened while the outlet valve 15d is closed. After the gas of the receiver 14 is supplied into the pipe through the regulator valve 13, the inlet valve 15c is closed to allow a certain amount of gas to stay inside the pipe. At this time, since the volume and temperature inside the pipe are fixed, a predetermined amount of gas is stored in the pipe when only the pressure of the gas is determined. In this state, when the outlet valve 15d is opened, the gas inside the pipe is supplied into the plastic molding machine 30 by gas pressure, and a large plastic molding machine requires a larger amount of high pressure inert gas, which is shown in FIG. 3B. As described above, a gas reservoir 15e that may store gas may be additionally installed.

As described above, the gas supply apparatus for producing foamed plastics of the present invention supplies a certain amount of gas continuously or intermittently into the plastic molding apparatus so as to be mixed with molten plastic so that foamed plastic having sufficient mechanical strength can be mass produced. This has the advantage.

Claims (12)

A gas compression means for receiving an inert gas that forms bubbles in the plastic from a gas storage means and compressing the gas at a high pressure; receiving means for receiving the high pressure gas compressed by the gas compression means and storing the gas at a constant pressure; A gas supply means for supplying a predetermined amount continuously or intermittently to the foamed plastic molding machine after temporarily storing the high pressure gas delivered from the means, and a shutoff valve installed between the gas supply means and the plastic molding machine to interrupt the supply of gas; ; In the gas supply device for producing a foamed plastic comprising a control unit for controlling the operation of the gas compression means and the shutoff valve, The gas supply means is a gas supply device for producing a foamed plastic, characterized in that for supplying the plastic molding machine by adjusting the amount of gas supplied so that the gas is mixed with the plastic contained in the cylinder of the plastic molding machine. The method of claim 1, The compression means is a gas supply device for producing a foamed plastic, characterized in that the gas booster is composed of a multi-stage to compress the gas to a sufficient pressure within a predetermined time even when the pressure of the gas storage means. The method of claim 1, The gas storage means is a gas supply device for producing a foamed plastic, characterized in that the pressure sensor for detecting the internal pressure to block the operation of the compression means through the control unit. The method of claim 1, The receiving means is made of a foamed plastic comprising a main receiver for temporarily storing the compressed gas at high pressure so that the pressure is uniform, and a sub receiver for receiving a high pressure gas stored in the main receiver to provide a more stable gas supply. Gas supply for manufacturing. The method of claim 4, wherein A gas supply device for manufacturing foamed plastic, characterized in that a regulator valve is installed between the main receiver and the sub receiver to adjust the flow rate of gas. The method of claim 4, wherein The main receiver and the sub-receiver is a gas supply device for producing a foamed plastic, characterized in that provided with a safety valve for releasing the gas when the specified pressure exceeds. The method of claim 1, A gas supply device for manufacturing foamed plastic, characterized in that a regulator valve is installed between the receiving means and the gas supply means to store the high pressure gas at a desired pressure in the gas supply means. The method of claim 1, The gas supply device is a gas supply device for producing a foamed plastic, characterized in that provided with a temperature control means to adjust the internal temperature to a desired value. The method of claim 8, The gas supply means is a gas supply device for producing a foamed plastic, characterized in that a pump-type container for supplying gas to the plastic molding machine using a piston is used. The method of claim 9, The pump-type container is a gas supply device for producing a foamed plastic, characterized in that the variable capacity type that can change the internal volume by moving the piston back and forth. The method of claim 1, The gas gas supply means is a gas supply device for producing a foamed plastic, characterized in that the tubular container for adjusting the gas supply amount by using the gap between the valve and the diameter of the pipe. The method of claim 11, The tubular container is a gas supply device for producing a foamed plastic, characterized in that provided with a gas reservoir to supply more gas to the plastic molding machine.