KR101941041B1 - Filling foam beads into the hollow body - Google Patents

Abstract

The present invention relates to a method for filling foamed beads into a hollow body, and more specifically, provides a method for filling foamed beads into a hollow body, which can perform uniform foam molding because steam piping of a double pipe structure is used to simultaneously supply and suck steam.

Description

[0002] Filling foam beads into the hollow body is filled in a hollow body,

The present invention relates to a foamed bead filling method in a hollow body, and more particularly, to a foamed bead filling method in which a foamed bead is filled in a hollow body capable of performing uniform foam molding, Thereby providing a filling method.

Synthetic resin foam is formed by forming a large number of small bubbles inside a synthetic resin. It is not only light but also widely used as a packaging material, a shock absorbing material, and a lightweight structural material. In the case of a floating buoyant material, filling foam beads inside can serve as a secondary booster material and greatly improve durability.

Methods for producing such synthetic resin foams include chemical methods and physical methods. The chemical method is a method in which a synthetic resin and a foaming agent are well mixed and then subjected to appropriate operation to decompose the foaming agent to generate a gas to produce a foam. The physical method is a method of producing a foam by infiltrating the resin into the resin and then expanding under reduced pressure . Chemical methods are mainly applied to the foaming of polyurethanes and polyolefins, and physical methods are mainly applied to the foaming of polystyrene and polyolefins.

As environmental problems have arisen, methods of manufacturing synthetic resin expanded particles by physical methods rather than chemical methods have become widely adopted. Organic foaming agents such as CFC, propane, and butane and inorganic foaming agents such as carbon dioxide and nitrogen may be used as physical foaming agents. However, in consideration of air pollution, use of inorganic foaming agents such as carbon dioxide is increasing.

In a conventional process for producing a batch type expanded particle, resin particles are put into a reaction vessel (BP1) as a high-pressure hermetically sealed container together with water (dispersion medium) and a dispersant, and a foaming agent (carbon dioxide) , The foaming agent is infiltrated into the polyolefin particle, and the resin particles and water are discharged from the high-pressure vessel and expanded under reduced pressure through a foaming device (BP2, for example orifice) to produce expanded particles. During the foaming, the gas must be continuously supplied to the reaction tank from the foam gas storage tank (BP15) in order to maintain the pressure in the reaction tank (BP1). The particles thus foamed are passed through a cleaning device (BP3, a purpose of removing a dispersant powder adhering to the particle surface, etc.) and a dewatering device (BP4) and stored in a cycle (BP5). Such a manufacturing method is disclosed, for example, in U.S. Patent No. 4,379,859.

However, in the conventional foamed particle production process, there is a problem that the foamed gas (carbon dioxide) for back pressure supplied to the reaction tank at the time of foaming is discharged to the atmosphere after the foaming, and a problem that large- And the problem is that it takes time.

This is the usual method of forming expanded particles. The expanded particles stored in the silo contain foam gas in the air bubbles, which must be replaced with air before molding (can be replaced by air or by blowing in hot air). If butane is used as blowing agent, it should be replaced due to the risk of fire. If carbon dioxide is used as blowing agent, it should be replaced due to insufficient expansion force. In the molding plant, the foamed particles which have been completely replaced are usually put in a pressure vessel before putting them into a molding machine, and they are placed under pressure with air. The purpose of the foamed particles is to increase the internal pressure in the particle bubbles, thereby enhancing the expansion force during molding.

The polyolefin expanded particles can be molded using a mold having various conditions and can be produced by compression molding (Japanese Patent Publication (Kokoku) No. 46-38359), pressure aging (Japanese Patent Laid-Open No. 51-22951 ), Compression charging method (Japanese Patent Publication No. 4-462217), atmospheric pressure charging method (Japanese Patent Publication No. 6-22919), other methods (Japanese Patent Publication No. 6-22919 ) And the like. Double compression molding and pressure aging are commonly used.

In the compression molding method, the polyolefin expanded particles are filled in a cavity made of a pair of molds of a male die and a male die under atmospheric pressure or reduced pressure, and then the die cavity is compressed so that the volume of the die cavity is reduced by 5 to 70%. Then, Followed by heating and fusing.

In the pressure aging method, at least one of a volatile foaming agent and an inorganic gas is previously treated with expanded particles to increase the secondary foaming power (expansion force) of the expanded particles, and then, with the secondary foaming power being maintained, The foamed particles are filled in a cavity made of a pair of molds of a metal mold, and then a heat such as steam is introduced into the metal mold cavity to heat and melt the expanded particles.

The above molding process has a problem that the transportation cost of the foam beads, the cost of pre-treatment (press-aging method), and the cost of energy (heating and cooling for molding) are excessive.

The continuous type foamed particle production method (see U.S. Patent No. 5,928,674 and Fig. 14) is advantageous in that it requires less equipment cost than the above-described batch type production method and does not require a back pressure gas at the time of foaming, And there is a disadvantage that a washing process is required after foaming. The method of producing continuous expanded particles has not yet been commercialized.

FIG. 5 is a view showing a state where steam is injected for foaming the beads filled in the conventional hollow body. Referring to FIG. 5, in the conventional method of filling the foamed beads in the hollow body, the steam is blown at a proper pressure, but the vent is not smoothly discharged. Also, steam is generated from a plurality of steam injection nozzles. However, there is a problem that defective foaming occurs at a portion where steam is not directly supplied although the foaming is normally performed around the nozzle.

Korean Patent No. 10-0212461 Korean Patent No. 10-1853824 Korean Patent Publication No. 10-2017-0089405 Korean Patent Publication No. 10-2010-0007270

Accordingly, it is an object of the present invention to provide a foamed bead filling method in a hollow body which can perform uniform foam molding because steam supply and suction are simultaneously performed using a double pipe structure steam pipe.

The problems to be solved by the present invention are not limited to those mentioned above, but should be clearly understood by those skilled in the art from the concrete embodiments of the invention.

The method of filling a foam bead in a hollow body according to the present invention comprises the steps of filling beads in a hollow body having at least one insertion hole on one side thereof; Inserting a double pipe structure steam pipe into the insertion hole of the hollow body; Injecting steam in the steam pipe to form beads filled in the hollow body into foam beads and sucking the injected steam and discharging the beads to the outside of the hollow body; And stopping suction of the steam and removing the steam pipe from the hollow body and aging the foamed bead when the foamed bead is completed, wherein the steam pipe has a plurality of suction holes for sucking steam on the outer circumferential surface thereof, An outer tube formed perpendicularly to the hollow body; An inner tube inserted into the outer tube and having a lower end through a lower surface of the outer tube and seated on a bottom surface of the hollow body, and a lower end through which the steam is injected; Wherein the steam is supplied to the upper end of the inner pipe through the injection port provided at the lower end of the inner pipe, and the steam is supplied to the upper end of the outer pipe in a horizontal direction along the bottom surface of the hollow body And the steam injected along the bottom surface of the hollow body is lifted up to make contact with the beads filled in the hollow body and then sucked into the suction holes of the outer tube and moved along the space between the outer tube and the inner tube And then discharged to the outside through the suction / discharge pipe.

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According to the foamed bead filling method in the hollow body according to the present invention, since steam supply and suction are simultaneously performed using the double pipe structure steam pipe, uniform foam molding can be performed.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the detailed description below.

1 is a block diagram showing an embodiment of a foamed bead filling method in a hollow body according to the present invention.
2 is a front view showing a structure of a steam pipe according to the present invention.
Fig. 3 is a longitudinal sectional view of Fig. 2. Fig.
FIG. 4 is a sectional view showing a state in which a steam pipe is installed in a hollow body according to the present invention.
FIG. 5 is a view showing a state where steam is injected for foaming the beads filled in the conventional hollow body

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

In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the terms described below are defined in consideration of the functions of the present invention, and may vary according to the intention of the user, the operator, or the precedent. Therefore, the definition should be based on the contents throughout this specification.

2 is a front view showing a structure of a steam pipe according to the present invention, and Fig. 3 is a cross-sectional view of the longitudinal section of Fig. 2, And FIG. 4 is a sectional view showing a state where a steam pipe is installed in a hollow body according to the present invention.

1 to 4, a method of filling a foamed bead into a hollow body according to the present invention comprises a step S1 of filling a bead into a hollow body 10, a step S1 of filling a hollow body 10 with an insert hole 11 of the hollow body 10, A step S2 of inserting a steam pipe 100 having a double tube structure into the steam pipe 100 and a step of spraying steam from the steam pipe 100 to foam the beads filled in the hollow body 10 into foam beads, (10), the steam pipe (100) is removed from the hollow body (10) by stopping the steam injection and the steam suction when the foamed bead is completed, And S4 of aging the beads.

The hollow body 10 in the step S1 may be a buoyant material used in floating structures such as a floating bridge, a floating solar photovoltaic module, a mooring platform, and the like.

In addition, the foamed beads are formed in the hollow body 10 to increase the strength of the foamed beads, and the foamed beads serve as a secondary booster. The hollow body 10 is provided with an insertion hole 11, And a fitting hole 13 is formed in the bottom of the hollow body located in the lower portion of the hollow body.

The beads filled in the hollow body in step S1 may be polystyrene resins, and the foamed beads to be molded in step S3 may be expanded polystyrene resin (EPS), but the present invention is not limited thereto, and other resins such as polypropylene resin Can also be applied.

Further, since the polystyrene resin acts on the steam to form the expanded polystyrene resin, it is known in Korean Patent Registration No. 10-0212461 and the like, so that the details thereof will be omitted.

The insertion hole 11 and the fitting hole 13 serve to insert and fix the steam pipe 100 in a detachable manner, and a plurality of holes may be formed to match the size of the hollow body.

In step S2, the steam pipe 100 is inserted into the insertion hole 11, and then the lower end of the steam pipe 100 is inserted into the fitting hole 13. Then, the steam pipe 100 is connected to the steam supply device 110 and the suction device 113 .

The steam piping 100 in step S3 includes a double pipe structure including an outer pipe 101 and an inner pipe 105. [

More specifically, the steam pipe 100 includes an outer pipe 101 having a plurality of suction holes 103 formed on an outer circumferential surface thereof, an inner pipe 105 disposed inside the outer pipe 101, And a suction / discharge pipe 109 installed to communicate with one side.

The inner pipe 105 is connected to the steam supply device 110 and the outer pipe 101 is connected to the suction device 113. The steam supply device 110 may include a boiler 111 for generating steam and a blower 112 for supplying steam generated in the boiler 111. The suction device 113 may include a suction pump For example.

In the step S3, steam is injected from the steam pipe 100 to form beads filled in the hollow body 10 into foam beads, and at the same time, the injected steam is sucked and discharged to the outside of the hollow body 10 The steam is supplied from the upper end of the inner pipe 105 to the lower side and the steam is injected into the bead filled in the hollow body 10 through the injection port 107 provided at the lower end of the inner pipe 105.

The jetting port 107 protrudes downward with respect to the outer surface, and a plurality of jetting ports 107 are formed along the outer circumferential surface to spray the steam in the lateral direction. The injected steam rises and comes into contact with the filled beads.

The steam injected into the hollow body 10 is sucked through the suction hole 103 and the suction and discharge pipe 109 of the outer pipe.

Since the suction holes 103 are formed at predetermined intervals along the longitudinal direction of the outer pipe 101, the steam sprayed in the lateral direction at the bottom of the hollow body 10 is lifted up by the suction force generated in the suction hole 103 This movement causes the steam to make uniform contact with the beads filled in the inside.

Conventionally, even if the steam is sprayed at an appropriate pressure, since there is only a hole for steam exhaust on one side of the hollow body, not only smooth steam exhaustion is performed, but also a region near the jet opening where steam is sprayed and a steam contact There has been a problem that molding defects occur because the amount of deviation is large.

However, in the present invention, by employing a system for sucking steam together with steam injection, the above-mentioned problems can be solved easily.

In the meantime, in the present invention, it is possible to recycle the heat energy remaining in the steam by reheating the waste steam without discarding the inhaled steam after injecting the thermal energy of the steam into the hollow body for more efficient use.

The reheating steam heats the steam sucked and discharged through the suction and discharge pipe 109 to a temperature at which it is supplied into the hollow body 10. The suction and discharge pipe 109 is connected to the circulation pipe 115 communicating with the boiler 111, And a discharge pipe 117 for discharging to the outside, and can selectively open and close the circulation pipe and the discharge pipe as necessary.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities. Accordingly, the scope of the present invention should be construed as being limited to the embodiments described, and it is intended that the scope of the present invention encompasses not only the following claims, but also equivalents thereto.

10: hollow body 11: insertion hole
13: Insertion hole
100: steam piping 101: appearance
103: suction hole 105: inner pipe
107: jetting port 109: suction and discharge pipe
110: steam supply device 111: boiler
112: Blower 113: Suction device
115: circulation piping 117: exhaust piping

Claims (2)

Filling a bead in a hollow body having at least one insertion hole on one surface thereof;
Inserting a double pipe structure steam pipe into the insertion hole of the hollow body;
Injecting steam in the steam pipe to form beads filled in the hollow body into foam beads and sucking the injected steam and discharging the beads to the outside of the hollow body;
And stopping the steam injection and suction when the foamed bead is formed, removing the steam pipe from the hollow body, and aging the foamed bead,
In the steam pipe,
An outer tube having a plurality of suction holes for sucking steam on an outer circumferential surface thereof and inserted perpendicular to the hollow body;
An inner tube inserted into the outer tube and having a lower end through a lower surface of the outer tube and seated on a bottom surface of the hollow body, and a lower end through which the steam is injected;
And a suction and discharge pipe communicating with an upper side of the outer tube,
When the steam is supplied from the upper end of the inner tube, the supplied steam is sprayed in the lateral direction along the bottom surface of the hollow body through the injection port provided at the lower end of the inner tube,
The steam sprayed along the bottom surface of the hollow body is lifted and contacts the beads filled in the hollow body, then sucked into the suction holes of the outer tube, moves along the space between the outer tube and the inner tube, And the foamed bead is discharged to the outside through the through hole.
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