JP3229810B2 - Method for producing foam molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a foamed molded article,
In particular, it relates to a method for heating foam beads.

[0002]

2. Description of the Related Art A conventional method of heating foam beads is to fill a cavity of a foaming mold with beads, and then supply high-pressure, high-temperature steam from a steam supply source to the mold as it is or under reduced pressure. Then, the filled beads were heated and foamed. The appropriate temperature for foaming the beads is from 125 ° C. to 105 ° C. depending on the type thereof, so the required temperature was set by reducing the vapor pressure in the mold. However, when the high-pressure steam is reduced in pressure, the steam in the mold is heated to a higher temperature than the steam pressure. The proper positive heating temperature only raises the mold because becomes superheated steam trying to set the vapor pressure becomes excessive heating a later step cooling step prolonged requires a large amount of cooling water, and Since a long cooling time is required, there is a disadvantage that a high cycle of the foaming process cannot be performed.

[0003]

SUMMARY OF THE INVENTION According to the present invention, the temperature of the heating steam immediately before the end of heating is reduced as much as possible to prevent the mold from being overheated, and the high cycle and cooling by shortening the cooling time in the next step. It is an object of the present invention to develop a method for producing a foamed molded article that does not require water or that requires as little water as possible, in particular, a method for heating foamed beads.

[0004]

[MEANS FOR SOLVING THE PROBLEMS] The invention according to claim 1 is provided.
Akira stated that (a) the beads (23) were filled into the mold cavities of the foaming molds (2) and (4), and (b) hot steam was injected into the foaming molds (2) and (4).
By supplying, the beads (23) are heated and foamed and foamed
Forming a compact, (c) cooling the foam compact, and (d) cooling
Foamed molded article as removed from the mold cavity
In the method for producing a foamed molded article, in the step (b),
After heating and foaming the beads (23) with steam at a constant temperature,
Lowered the temperature to heat the molded foam further
A method for producing a foamed molded article, characterized in that:

According to a second aspect of the present invention , in the method for producing a foamed molded article according to the first aspect, the step (b) comprises:
Spray cooling water (R) on steam in foaming mold (2) (4)
This lowers the temperature of the steam and simultaneously
It is characterized in that it is made to be Japanese steam . (See Fig. 1)

According to a third aspect of the present invention , in the method for producing a foamed molded article according to the first aspect, the step (b) comprises:
Cooling water (R) is added to the steam before it is supplied to the foaming molds (2) and (4).
Spraying reduces the temperature of the steam.
The feature is that the steam is sometimes made to be a saturated steam . (See Fig. 2)

According to a fourth aspect of the present invention , in the method for producing a foamed molded article according to the first aspect, the step (b) comprises:
Steam before being supplied to the foaming molds (2) and (4) in the cooling water (R)
To reduce the temperature of the steam.
The feature is that the steam is sometimes made to be a saturated steam . (See Fig. 3)

According to a fifth aspect of the present invention , in the method for producing a foamed molded article according to the first aspect, the step (b) comprises:
The steam before being supplied to the foaming molds (2) and (4) is
Reduces steam temperature by contact with water surface
At the same time, it is characterized in that the steam is made into saturated steam . (See Fig. 4)

According to a sixth aspect of the present invention , in the method for producing a foamed molded article according to the first aspect, the step (b) comprises:
Steam before being supplied to the foaming molds (2) and (4) is sent to the cooler (C).
Cooling to reduce the temperature of the steam
It is characterized by having done. (See Fig. 5)

[0010] According to the above method, prior to completion of heating of the filling bead (23), lowering the temperature of the hot steam leaving the steam supply source (13), so heating the foamed molded at this vapor In addition, the mold temperature immediately before cooling is not excessively heated, and the mold temperature is quickly lowered when the process moves to the subsequent cooling step, so that the cooling step can be shortened. Further, at the same time as lowering the steam temperature, by making the steam a saturated steam that coexists with water, the surface of the mold and the foamed molded body is wet by the steam and the coexisting moisture at the end of heating. When the pressure inside the mold is reduced, the adhering water instantaneously evaporates to take away heat of vaporization, thereby effectively cooling the foamed article and drying the foamed article at the same time, thereby saving cooling water and cooling. High cycle can be realized by shortening the time.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows a foam molding machine (A) according to the present invention, in which a mold portion is a movable die plate (1), a movable mold (2) fixed to the movable die plate (1), a fixed die plate (3), Fixed dies (4) fixed to the fixed die plate (3), various pipes connected to the movable dies (2) and the fixed dies (4), and beads mounted on the fixed dies (4) Feeding device (21), ejector
(22). The movable die (2) is fixed to the movable die plate (1), and the movable die plate (1) is brought into contact with and separated from the fixed die (4) to open and close the die. The drive unit is not shown because it is known.

The piping connected to the fixed die plate (3) and the fixed mold (4) includes a steam pipe (5) (6), a cooling pipe (7) (8), There are air pipes (9) (10) and drain pipes (11) (12), each with a pressure reducing valve (5a) (6a),
Steam valve (5b) (6b), cooling water supply valve (7a) (8a), air opening / closing valve (9
a) (10a), vacuum valves (11a) (12a), and drain valves (13) (14). In addition, cooling pipes on the moving and fixed sides
(7) and (8) are connected to the spray pipes (7b) and (8b) installed in the movable mold (2) and the fixed mold (4), respectively. Also,
The steam pipes (5) and (6) are connected to a steam supply source (13) via a main steam pipe (15). Drain piping on moving side and fixed side
(11) (12) are connected to the movable mold (2) and the fixed mold (4), respectively, and are branched and one end is a vacuum valve (11a) (12a)
To the vacuum source (16), and the other end is connected to a drain valve
It is connected to the drain (17) via (13) and (14).

Next, the operation of the present invention will be described. First, the movable die plate (1) is moved to stop cracking the movable mold (2) immediately before the fixed mold (4), and in this state, the bead supply device (21) is operated to operate the bead (23). Into the mold cavity. When the filling of the beads (23) into the mold cavity is completed, the movable die plate (1) is restarted to close the mold by pressing the movable mold (2) against the stationary mold (4). Move on to There are a plurality of heating foaming methods for beads (23), but since the procedure of heating foaming is not important in the present invention,
Here, only one representative method will be described. On the other hand, a characteristic part of the present invention lies in a method of supplying steam, and each embodiment will be described.

<< First Embodiment >> (One-way heating) In this step, the steam pressure is reduced by pressure reducing valves (5a) and (6a) in order to obtain a temperature required for heating the mold.
Steam valve (5b) for moving mold (2) and drain valve (14) for fixed mold (4)
, The steam valve (12a) is closed, and the steam valve (6b) of the fixed mold (4) and the vacuum valve (11a) and the drain valve (13) of the movable mold (2) are closed. In this step, steam flows from the mold (2) to the fixed mold (4) to foam the beads (23) in the mold cavity. Steam output from the steam supply source (13) is of a high pressure and high temperature, it passes through the main steam pipe (15) enters the moving mold (2) through a steam pipe (5), beads (23 ), Into the fixed mold (4), and through the drain valve (14) to the drain (17).

(Double-sided heating) When the one-way heating is completed, the open drain valve (14) is closed (this causes the drain pipes (11) and (12) to be closed) and the steam valve (5b). )
Keeps the steam valve closed (6
b) Open and move mold from steam pipe (5) and steam pipe (6)
Steam is supplied to (2) and the fixed mold (4), and both sides of the foam molded body in the mold cavity are heated from both sides. Before the completion of both-side heating, for example, when the foaming surface pressure reaches 65 to 90% of the final target value, or when the mold temperature reaches 65% of the target value.
When it reaches ~ 90%, both cooling water supply valves
(7a) Open (8a) and spray cooling water inside the moving mold (2) and fixed mold (4), cool the supplied high-temperature steam to low-temperature saturated The foamed product of the beads (23) is further heated at a low temperature from both sides of the mold (2) and the fixed mold (4). In this case, the steam temperature is preferably a temperature just above the final target mold temperature necessary for foaming the surface portion of the foam molded article. This temperature control is performed by detecting the vapor pressure in the molds (2) and (4) and controlling the pressure settings of the pressure reducing valves (5a) and (6a). With this, the moving mold
(2) The fixed mold (4) is kept at the minimum necessary temperature, excessive heating is suppressed, and cooling at the time of moving to the next cooling step becomes smooth. At the same time, the moving mold because the steam is saturated
(2) The surfaces of the fixed mold (4) and the foamed molded body are in a state where moisture is sufficiently attached.

(Drain discharge step) When the heating step is completed, both steam valves (5b) and (6b) and both cooling water supply valves (7a) and (8a) are closed, and the air open / close valves (9a) and (10a) are opened to compress. Mold air (2)
(4), and at the same time, open the drain valves (13) and (14) to discharge the drain and residual steam in the molds (2) and (4) out of the mold. Occasionally, the vacuum source (16) reduces the amount of steam and water that must be suctioned, thereby increasing the efficiency of vacuum suction. During this time, the vacuum valves (11a) (12a) are closed.

(Decompression cooling step) When the drain discharge step is completed, the air on / off valves (9a) (10a) and the drain valves (13) (14) are closed, and both vacuum valves (11a) (12a) are opened. Both vacuum valves (11a) (12a)
When is opened, the vacuum source (16) communicates with the movable mold (2) and the fixed mold (4), and the pressure inside the movable mold (2) and the fixed mold (4) is rapidly reduced. Then, the moisture adhering to the surface of the moving mold (2), the fixed mold (4) and the foamed molded body evaporates rapidly, deprives the foamed molded body of heat of vaporization, and does not require water cooling to form the foamed molded body. Can be cooled. At the same time, the adhered water evaporates, so that the foam molded article is in a dry state. In order to increase the efficiency of the vacuum pump, it is preferable to provide a condenser tank (not shown), cool the steam under reduced pressure with a water spray, and reduce a volume of the sucked steam by changing a part of the steam to water.

(Removal step) When the cooling step is completed,
Activate the movable die plate (1) to separate the movable mold (2) from the fixed mold (4) and open the mold.
By operating (22), the foam molded article is extruded from the fixed mold (4), and is taken out by a take-out machine (not shown) or by being dropped downward. When the removal is completed, the movable die plate (1) is operated again to advance the movable mold (2) to the cracking position, and the same operation as described above is repeated to continue the molding of the foam molded article.

<< Second Embodiment >> In this case, the location of the steam cooling by the spray applied to the steam before the end of the double-sided heating is different from that of the first case. That is, before supplying to the molds (2) and (4), cooling water (R) is sprayed on high-temperature steam in advance to lower the steam temperature, and at the same time, the steam is used as saturated steam, and this is used as the mold (2) ( 4).

<< Third Embodiment >> In this case, the steam cooling means before the completion of the above-mentioned double-sided heating is different from that in the first or second embodiment, and the steam cooling means is not supplied to the molds (2) and (4). Then, high-temperature steam is passed through the cooling water (R) to lower the steam temperature and at the same time to become saturated steam.

<< Fourth Embodiment >> In this case, the steam cooling means before the completion of the double-sided heating is different from those in the first to third embodiments, and is not supplied to the molds (2) and (4). Then, high-temperature steam is brought into contact with the surface of the cooling water (R) to lower the steam temperature and at the same time to make saturated steam.

Fifth Embodiment In this case, the means for cooling the steam before the completion of the double-sided heating is different from that in the first to fourth embodiments, and before the steam is supplied to the molds (2) and (4). Cooler
In (C), the steam temperature of the high-temperature steam is reduced.
In this case, since the cooling water (R) is not used, there is no water supply from the cooling water (R), and it depends exclusively on the saturation due to the decrease in the saturated steam pressure due to the temperature decrease.

[0023]

According to the method of the present invention, excessive heating of the mold temperature immediately before cooling can be suppressed, so that the subsequent cooling step can be shortened and a high cycle can be realized. In addition, since the foamed molded body is heated by saturated steam just before cooling, the surface of the mold and the foamed molded body are sufficiently wet at the end of the heating. The heat of the molded article is removed, and the effective cooling and drying of the foamed article can be performed simultaneously.

[Brief description of the drawings]

FIG. 1 is a schematic flowchart of a main part of a foam molding machine to which the method of the present invention is applied.

FIG. 2 is a flow chart of steam cooling by spraying in the method of the present invention.

FIG. 3 is a flow chart of steam cooling by immersion in cooling water in the method of the present invention.

FIG. 4 is a flow chart of steam cooling by contact with cooling water in the method of the present invention.

FIG. 5 is a flow chart of steam cooling in the case of forced cooling by a cooler according to the method of the present invention.

[Explanation of symbols]

 (A) ... foam molding machine (1) ... moving die plate (2) ... moving die (3) ... fixed die plate (4) ... fixed die (13) ... steam supply source (23) ... beads

Claims (6)

(57) [Claims] 1. A method according to claim 1, wherein: (a) beads are filled in a mold cavity of a foaming mold ; and (b) high-temperature steam is charged in said foaming mold.
To heat and foam the beads.
Forming a foam molded body, (c) cooling the foam molded body, (d) cooling
The retirement has been said foamed molded was taken out from the mold cavity, in the manufacturing method of the foamed molded, the step (b), the beads the vapor of a predetermined temperature
After heating and foaming, the temperature of the steam is lowered to
Characterized in that the foam molded body is further heated ,
A method for producing a foam molded article. 2. In the step (b), the foaming metal
By spraying the steam with cooling water in the mold,
At the same time as lowering the temperature of the steam,
The method for producing a foamed molded article according to claim 1, wherein: 3. In the step (b), the foaming metal is used.
Spraying cooling water on the steam before it is supplied to the mold.
With this, the temperature of the steam is lowered, and
The method for producing a foamed molded article according to claim 1, wherein the air is made into saturated vapor . 4. In the step (b), the foaming metal is used.
The steam before being supplied to the mold must be passed through the cooling water.
With this, the temperature of the steam is lowered, and
The method for producing a foamed molded article according to claim 1, wherein the air is made into saturated vapor . 5. In the step (b), the foaming metal is used.
The steam before being supplied to the mold is brought into contact with the surface of the cooling water.
By lowering the temperature of the steam,
The method for producing a foamed molded article according to claim 1, wherein the steam is a saturated steam . 6. In the step (b), the foaming metal is used.
Cooling the steam with a cooler before being supplied to the mold
Thereby, the temperature of the steam was reduced,
Item 4. A method for producing a foamed molded article according to Item 1 .