JP2014162207A - Foamed resin molding mold, foamed resin molding device, foamed resin-molded article, and method for producing the article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foamed resin molding mold in which the amount of steam to be used when a preliminarily-foamed resin is foam-molded can be reduced and the thermal-insulating material of which is hardly degraded or peeled off even when used for a long time.SOLUTION: The foamed resin molding mold includes: a first mold having a hollow steam chamber comprising a frame 6, a bracket-side back plate, and a first mold body having a plurality of steam holes; and a second mold having another steam chamber comprising the frame 6, a die plate, and a second mold body having a plurality of steam holes and is used for: charging a preliminarily-foamed rasin particle, which is obtained by preliminarily foaming a foamable thermoplastic resin particle, in a cavity 9 formed by joining the first mold body to the second mold body; and bringing steam into contact with the preliminarily-foamed rasin particle through the plurality of steam holes to produce a foamed resin-molded article. At least a part of the outside surface of the frame and the outside surface of the bracket-side back plate of the first mold, and the outside surface of the frame and the outside surface of the die plate of the second mold is covered with a thermal-insulating layer.

Description

  The present invention relates to an in-mold foam-molding mold for producing a thermoplastic resin foam-molded article such as a polystyrene-based resin foam-molded article by in-mold foam molding, and a foam molding apparatus including the same, and more particularly, to a steam used as a heating medium. The present invention relates to a foamed resin mold and a foamed resin molding apparatus that can reduce the amount used compared to conventional methods. The present invention also relates to a foamed resin molded product and a method for producing the same.

  Conventionally, in an in-mold foam molding apparatus for producing a thermoplastic resin foam molded article such as a polystyrene-based resin foam molded article by in-mold foam molding, the steam used during the production of the foam molded article can be reduced to reduce the manufacturing cost. Various techniques for energy saving have been proposed (see, for example, Patent Documents 1 to 4).

  Patent Document 1 discloses an apparatus for producing a foamed molded body by sintering pre-expanded polymer beads using superheated steam in a mold having a plurality of parts, and the mold is introduced with superheated steam. The foam molded body is placed in a steam chamber, where superheated steam enters the mold from the steam chamber through the nozzle, and the inner wall of the steam chamber is coated with a cured epoxy resin for thermal insulation. A manufacturing apparatus is disclosed.

  Patent Document 2 includes a first mold and a second mold provided with a plurality of steam holes, and expandable resin particles in a cavity formed by combining the first and second molds. In a foamed resin mold for producing a foamed resin molded product by contacting the foamable resin particles with vapor through the plurality of vapor holes, moisture resistance is provided between the mold support and the back plate. There is disclosed a foamed resin mold characterized by laminating a protective material made of a hard material and a heat insulating material made of a compression-resistant heat insulating material.

  In Patent Document 3, expandable thermoplastic resin particles are introduced into a molding chamber space constituted by a pair of concave and convex middle molds in a mold, and then in the molding chamber space from a steam chamber provided at the back of the molding chamber space. This is a foam molding die used for foam molding in which steam is introduced into the molding chamber to heat and foam the thermoplastic resin particles in the molding chamber space, foam and fuse, and then cooled and taken out of the mold to obtain a molded product of a desired shape. In addition, a part or the whole of one or more steam chamber surfaces selected from the frame-side steam chamber surface, the back plate-side steam chamber surface, and the center plate-side steam chamber surface that form the steam chamber contains hollow silica particles. A foam molding die characterized by being coated with a silicone resin is disclosed.

  In Patent Document 4, expandable thermoplastic resin particles are introduced into a molding chamber space constituted by a pair of middle molds in a mold, and then the molding chamber space is formed from a steam chamber provided on the back side of the molding chamber space. For foam molding to be used for foam molding, which introduces steam to heat the foamable thermoplastic resin particles in the molding chamber space, foam and fuse, then cool and take out from the mold A coating layer formed by thermosetting a thermosetting water-soluble resin containing aluminosilicate soda glass having a hollow bead structure on a part or the entire surface of the steam chamber except for the steam chamber surface in the middle mold A foam molding die characterized by being formed is disclosed.

JP 2003-236872 A JP 2004-90368 A JP 2004-148777 A JP 2006-212814 A

The foamed resin molds disclosed in Patent Documents 1 to 4 described above are provided with a heat insulating material inside the steam chamber as a means for reducing the steam used at the time of manufacturing the foam molded body. It was intended to prevent heat energy from leaking outside the frame and reduce the amount of steam used during in-mold foam molding.
However, as disclosed in Patent Documents 1 to 4, in the structure in which the heat insulating material is provided inside the steam chamber of the molding die, when the molding die is used for a long time, the heat insulating material itself or the adhesive is vaporized. There is a problem that the contact deteriorates and peels off.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a foamed resin molding die that can reduce the amount of steam used during foam molding in a mold and that does not easily cause deterioration or peeling of a heat insulating material even when used for a long time. To do.

To achieve the above object, the present invention provides a first mold having a hollow steam chamber constituted by a frame, a bracket-side back plate, and a first mold body provided with a plurality of steam holes, and a frame. A second mold having a hollow steam chamber composed of a die plate and a second mold body provided with a plurality of steam holes, and is formed by combining these first and second mold bodies. Foamed resin in which foamed thermoplastic resin particles are produced by filling the cavity with prefoamed resin particles obtained by prefoaming foamable thermoplastic resin particles, and bringing the vapor into contact with the prefoamed resin particles through the plurality of vapor holes. In the molding die, the foam is characterized in that at least a part of the outer surface of the frame of the first die and the outer surface of the bracket side back plate and the outer surface of the frame of the second die and the outer surface of the die plate are covered with a heat insulating layer. Tree Providing a mold.
In the foamed resin mold of the present invention, the heat insulating layer preferably has a thermal resistance value (R) in the range of 0.05 to 0.25 m ² · K / W.
In the foamed resin mold of the present invention, it is preferable that the heat insulating layer has a thickness of 8 mm or less.
In the foamed resin mold of the present invention, the heat insulating layer may include an aluminum film laminated heat-resistant nonwoven fabric.
In the foamed resin mold of the present invention, it is preferable that the heat insulating layer includes a coating film of a heat insulating paint.
The present invention also provides a foamed resin molding apparatus having the foamed resin mold.
Moreover, this invention provides the manufacturing method of the foamed resin molded product which manufactures a foamed resin molded product using the said foam molding apparatus.
Moreover, this invention provides the foamed resin molded product obtained from the manufacturing method of the said foamed molded product.

  The foamed resin molding die of the present invention has a structure in which at least a part of the outer surface of the frame of the first mold and the outer surface of the bracket side back plate, and the outer surface of the frame of the second die and the outer surface of the die plate are covered with a heat insulating layer. Therefore, the amount of steam used during in-mold foam molding can be reduced, and even when used for a long time, the heat insulating layer is unlikely to deteriorate or peel off.

It is a block diagram which shows an example of the foamed resin molding apparatus provided with the foamed resin molding die of this invention. It is sectional drawing which shows the 1st example of a heat insulation layer. It is sectional drawing which shows the 2nd example of a heat insulation layer. It is sectional drawing which shows the 3rd example of a heat insulation layer. It is sectional drawing which shows the 4th example of a heat insulation layer. It is sectional drawing which shows the 5th example of a heat insulation layer.

Hereinafter, an embodiment of an in-mold foam molding method of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing an example of a foamed resin molding apparatus (hereinafter referred to as a molding apparatus) provided with a foamed resin molding die (hereinafter referred to as a molding mold) of the present invention.

The molding apparatus 1 includes a concave mold 2 that is a first mold and a convex mold 3 that is a second mold, and a mold 4 that can be closed and opened when these molds approach and separate from each other. have.
The concave mold 2 has a hollow steam chamber 10 composed of a frame 6, a bracket side back plate 8a, and a concave main body 5 provided with a plurality of steam holes. The convex mold 3 has a hollow steam chamber 11 composed of a frame 6, a die plate 8b, and a convex main body 7 provided with a plurality of steam holes. The frame 6 constitutes four side surfaces of the molding die 4 having a substantially rectangular shape when the die is closed as shown in FIG. 1, and the bracket side back plate 8a and the die plate 8b constitute upper and lower surfaces. In the mold closed state shown in FIG. 1, a cavity 9 is formed between the concave mold body 5 and the convex mold body 7 so as to match the outer shape of the foamed molded product to be manufactured, such as a fish box.

  A steam supply line is connected to the steam chamber 10 on the concave side 2 via a concave side pressure regulating steam valve 12, and a drain line is connected to the opposite position via a concave side drain valve 13. A vacuum exhaust pipe line is connected to the pipe line via a vacuum valve 14. Further, a cooling water supply pipe line is inserted into the steam chamber 10 on the concave mold 2 side via a cooling water valve 15, and a pressure gauge 16 is connected to an appropriate place.

  Similarly, a steam supply conduit is connected to the steam chamber 11 on the convex 3 side via a convex pressure regulating steam valve 17, and a drain conduit is connected to the opposite position via a convex drain valve 18. And a vacuum exhaust line is connected to the drain line via a vacuum valve 19. In addition, a cooling water supply pipe line is inserted into the steam chamber 11 on the convex mold 3 side via a cooling water valve 20, and a pressure gauge 21 is connected to an appropriate place. Although not shown in the drawing, the pre-foamed particle supply port connected to the supply pipe for filling the pre-foamed particles in the cavity 9 and the molded product after the molding are removed from the mold at appropriate positions of the mold 4. A pin for extruding is provided.

  At least a part of the outer surface of the frame 6, the outer surface of the bracket side back plate 8 a and the outer surface of the die plate 8 b of the mold 4 is covered with a heat insulating layer.

In the foamed resin mold of the present invention, the heat insulating layer preferably has a thermal resistance value (R) in the range of 0.05 to 0.25 m ² · K / W, and 0.08 to 0.20 m ² ·. More preferably, it is within the range of K / W.
Here, the thermal resistance value (R) [m ² · K / W] is the thickness (d) [m] of the material of the heat insulating layer ÷ the thermal conductivity (λ) [W / (m · K) of the material of the heat insulating layer. )]. When the heat insulation layer is composed of a plurality of heat insulating materials, the heat resistance value is represented by the sum of the heat resistance values of the heat insulating materials.

(Measurement method of thermal conductivity λ)
Foam moldings, and vertical 200 mm × horizontal 200 mm × thickness test piece A test piece was cut out of the rectangular parallelepiped 10 to 25 mm, the thermal conductivity of the test piece A with lambda _A. Next, a heat insulating layer B is provided on the entire surface of one side (200 mm × 200 mm) of the test piece A to provide a test piece C with a uniform thickness of 0.5 to 8 mm, and the thermal conductivity of the test piece C is λ _C And
Thermal conductivity lambda _A test piece A is calculated as follows. Using a measuring device commercially available from EKO SEIKI under the trade name “HC-074 / 200”, the low temperature plate of the measuring device is 15 ° C. lower than the average temperature of the test piece A, and the high temperature plate is the average of the test piece A After setting the temperature 15 ° C. higher than the temperature, the thermal conductivity λ _A of the test piece A is measured according to JIS A 1412-2: 1999 “Measurement Method of Thermal Resistance and Thermal Conductivity of Thermal Insulation Material—Part 2: Heat Flow Meter Method (HFM method) "is measured according to the method described. In addition, the average temperature of the test piece A shall be 3 points | pieces, 0, 20, and 30 degreeC. Based on the obtained thermal conductivity, a regression line with the horizontal axis representing temperature and the vertical axis representing thermal conductivity is drawn, and the thermal conductivity λ _A of the test piece A at 23 ° C. is calculated. Moreover, in the case of the test piece C, the heat conductivity in 23 degreeC when the heat insulation layer B is made to contact the low temperature board of a measuring apparatus, and 23 degreeC in the case where the heat insulation layer B is made to contact the high temperature board of a measurement apparatus. From the average value of the thermal conductivity, the thermal conductivity λ _C of the test piece _C is calculated.
At this time, the amount of heat Q flowing through the test piece C per unit time is expressed by the following equation.
Q = λ _C · (T ₁ −T ₃ ) / d _C
= Λ _A · (T ₁ −T ₂ ) / d _A
= Λ _B · (T ₂ −T ₃ ) / d _B
Here, Q: the amount of heat flowing in the test piece C per unit time (W / m ² )
λ _C : Thermal conductivity of test piece C (W / (m · K))
d _C : thickness of test piece C (m)
λ _A : Thermal conductivity of test piece A (W / (m · K))
d _A : thickness of test piece A (m)
λ _B : thermal conductivity of heat insulating layer B (W / (m · K))
d _B : the thickness (m) of the heat insulating layer B (where d _B = d _C −d _A )
T ₁ , T ₂ , T ₃ : Temperature distribution inside the test piece C (K) (where T ₁ > T ₂ > T ₃ )
Thus, the thermal conductivity lambda _B of the heat insulating layer B is calculated by the following equation.
λ _B = (d _C −d _A ) / [(d _C / λ _C ) − (d _A / λ _A )]
The foamed molded body used for the test piece A is not particularly limited as long as the thermal conductivity does not change during the measurement, but is a Styrofoam IB manufactured by Dow Kako Co., Ltd., thickness 20 mm, thermal conductivity λ = 0.040 (W / (M · K)) can be preferably used.
The thickness of the heat insulating layer B provided on one side of the test piece A is not particularly limited as long as it is in the range of about 0.5 to 8 mm, but a thickness of about 3 mm can be suitably used.
As described above, the method for measuring the thermal conductivity when the thickness of the heat insulation layer is as thin as about 0.5 to 8 mm has been described, but when the thickness of the heat insulation layer is originally 10 to 25 mm, the length is 200 mm × width 200 mm × A test piece having a rectangular parallelepiped shape having a thickness of 10 to 25 mm was heated in accordance with JIS A 1412-2: 1999 using a measuring device commercially available from EKO SEIKI under the trade name “HC-074 / 200”. Measure conductivity.

(Measurement method of thermal resistance value R)
The thermal resistance value R of the heat insulation layer is calculated by the following formula.
R = d / λ
Here, R: thermal resistance value of the heat insulating layer (m ² · K / W)
d: thickness of heat insulating layer (m)
λ: thermal conductivity of the heat insulating layer (W / (m · K))
The thermal resistance value R _n when n different heat insulating layers are provided as the heat insulating layer is calculated by the following equation.
R _n = d ₁ / λ ₁ + d ₂ / λ ₂ +... + D _n / λ _n

  In the foamed resin mold of the present invention, the heat insulating layer preferably has a thickness of 8 mm or less, more preferably 7 mm or less, and most preferably in the range of 0.5 to 6 mm. If the thickness of the heat insulating layer is 8 mm or less, when the heat insulating layer is formed on the outer surface of the frame 6, or the outer surface of the frame 6, the outer surface of the bracket side back plate 8a, and the outer surface of the die plate 8b, the heat insulating layer is not excessively bulky and molded. Less impact on work.

FIG. 2 is a diagram illustrating a first example of a heat insulating layer.
In this example, the heat insulating sheet 32 is bonded to the entire outer surface of the frame 6 of the mold 4 via the adhesive layer 33. A heat insulating layer 34 is constituted by the adhesive layer 33 and the heat insulating sheet 32.
The heat insulating sheet 32 is not particularly limited, and can be appropriately selected from various commercially available heat insulating sheets. Examples of the commercially available heat insulating sheet 32 that is preferable in the present invention include a product name “single-sided aluminum laminated heat-resistant felt” manufactured by Kikuchi Sheet Kogyo Co., Ltd., which is a heat-resistant sheet in which an aluminum layer 32a is laminated on one side of a heat-resistant nonwoven fabric. .
The adhesive used for adhering the heat insulating sheet 32 is not particularly limited as long as it can firmly and stably adhere and fix the heat resistant sheet 32 to the outer surface of the frame 6, but from the viewpoint of heat resistance and water resistance, it is silicone. Resin-based adhesives are preferred.

  Since the heat insulating layer 34 of this example is mainly the thin heat insulating sheet 32, the molding die 4 is not bulky and does not obstruct the molding operation, and has little influence on the molding operation. In addition, the mold 4 formed with the heat insulating layer 34 of the present example is provided with heat insulating performance, so that the amount of steam used during foam molding in the mold can be reduced. It is difficult to cause deterioration and peeling.

FIG. 3 is a diagram illustrating a second example of the heat insulating layer.
In this example, a heat insulating sheet 32 is bonded to the entire outer surface of the frame 6 of the mold 4 via an adhesive layer 33, and a heat insulating coating film 35 is laminated on the outer surface of the heat insulating sheet 32. A heat insulating layer 36 is constituted by the adhesive layer 33, the heat insulating sheet 32, and the coating film 35 of the heat insulating paint.
Examples of the heat insulating paint include those containing ceramic hollow beads such as amorphous silica and silica hollow beads for imparting heat insulating performance, and a synthetic resin component for forming a coating film. The heat insulating paint may be a solvent dilution type paint or an energy curable paint such as light or heat. The heat insulating paint used for forming the coating film 35 was prepared by mixing suitable ceramic hollow beads such as amorphous silica and silica hollow beads, a synthetic resin component, and additives such as a solvent and a curing agent. A coating composition may be used, and may be used by appropriately selecting from various commercially available heat insulating coatings. Examples of such commercially available heat-insulating paints include the product name “Ceramic Cover CC100” manufactured by Nippon Telenics Co., Ltd., which is a heat-insulating paint containing amorphous silica.

  The heat insulating layer 36 of this example has the same effect as the heat insulating layer 35 of the first example described above, and furthermore, the heat insulating performance of the mold 4 is obtained by laminating the coating film 35 of the heat insulating paint on the outer surface of the heat insulating sheet 32. Can be further improved, and the amount of steam used during in-mold foam molding can be further reduced.

FIG. 4 is a diagram illustrating a third example of the heat insulating layer.
In this example, glass wool 37 is bonded to the entire outer surface of the frame 6 of the mold 4 via an adhesive layer 33. The heat insulating layer 38 is constituted by the adhesive layer 33 and the glass wool 37.
The glass wool 37 can be used by appropriately selecting from various commercially available products. Examples of such commercially available products include “Glaslon Wool GW32” manufactured by Asahi Fiber Glass Co., Ltd. be able to.
The adhesive used for the adhesive layer 33 is not particularly limited as long as it can firmly and stably adhere and fix the glass wool 37 to the outer surface of the frame 6. However, from the viewpoints of heat resistance and water resistance, it is a silicone resin adhesive. Agents are preferred.

  Since the heat insulating layer 38 of this example is mainly made of thick glass wool 37, there is a possibility that the molding die 4 is bulky and hinders the molding operation.

FIG. 5 is a diagram illustrating a fourth example of the heat insulating layer.
In this example, a heat insulating layer 35 a made of the heat insulating coating film 35 is formed over the entire outer surface of the frame 6 of the mold 4.

The heat insulating layer 35a is formed by applying a heat insulating paint over the entire outer surface of the frame 6 of the mold 4 and drying it to cure the synthetic resin component. It is formed by curing the synthetic resin component by irradiating energy such as. The method of applying the paint over the entire outer surface of the frame 6 of the mold 4 is not particularly limited, and can be performed by a conventionally known coating method such as spray coating.
The thickness of the heat insulating layer 35a is preferably 8 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less.

  Since the heat insulating layer 35a of this example is a thin coating film 35, the molding die 4 is not bulky and does not obstruct the molding operation, and has little influence on the molding operation. In addition, the mold 4 formed with the heat insulating layer 35a of this example can reduce the amount of steam used during in-mold foam molding by providing heat insulating performance, and the heat insulating layer 35a can be used even for a long time. It is difficult to cause deterioration and peeling.

FIG. 6 is a diagram illustrating a fifth example of the heat insulating layer.
In this example, in addition to the entire outer surface of the frame 6 of the mold 4, a heat insulating layer 35 a composed of a coating film 35 of heat insulating paint containing ceramic hollow beads is formed on the outer surface of the bracket side back plate 8 a and the outer surface of the die plate 8 b. It has a configuration.

  The heat insulating layer 35a of this example has the same effect as that of the fourth example, and the heat insulating paint film is applied not only to the entire outer surface of the frame 6 of the mold 4 but also to the outer surface of the bracket side back plate 8a and the outer surface of the die plate 8b. With the configuration in which the heat insulating layer 35a made of 35 is formed, the heat insulating performance of the molding die 4 can be further improved, and the amount of steam used during in-mold foam molding can be further reduced.

  In order to produce a thermoplastic resin foam molded article such as a polystyrene-based resin foam molded article using the molding apparatus configured as described above, the concave mold 2 and the convex mold 3 are brought close to each other and the mold 4 is closed. The pre-expanded particles are filled in the cavity 9, and then the pre-expanded particles are fused together while being foamed by steam heating of the mold 4, then the in-mold foam molding is performed, and then the mold 4 is cooled, and then the mold 4 Is performed, and the foamed molded product is released from the mold.

  The pre-foamed particles used in the in-mold foam molding method are obtained by pre-foaming synthetic resin particles containing a foaming agent. As the synthetic resin constituting the synthetic resin particles, conventionally, foamed resin molded products are used. The resin material used for production can be appropriately selected and used, and is not particularly limited. For example, polystyrene, high impact polystyrene, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer Polystyrene resins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, polyester resins such as polyethylene terephthalate, and the like. Polystyrene resins are preferred because of their strength and moldability.

  Further, as the foaming agent, organic compounds that have a boiling point below the softening point of the synthetic resin and are gaseous or liquid at normal pressure are suitable. For example, propane, butane, pentane, cyclopentane, cyclopentadiene, hexane Further, hydrocarbons such as petroleum ether, low boiling point ether compounds such as dimethyl ether, diethyl ether, dipropyl ether, and methyl ethyl ether, inorganic gases such as carbon dioxide and nitrogen, and the like are used. These foaming agents may use only 1 type and may use 2 or more types together. As a content rate of a foaming agent, it is 1-20 mass% with respect to the synthetic resin particle mass, Preferably it is 2-10 mass%. When the content of the foaming agent is less than the above range, the foaming ratio of the foamed molded product is insufficient and a lightweight foam cannot be obtained. On the other hand, even if the content of the foaming agent exceeds the above range, a further increase in the expansion ratio cannot be substantially expected, and foaming becomes unstable, which is not preferable.

In the in-mold foam molding method, after filling the pre-expanded particles in the cavity 9 of the mold 4, the following heating steps (a) to (e),
(A) a mold heating step of opening the concave side pressure regulating steam valve 12, the convex side pressure regulating steam valve 17, the concave side drain valve 13 and the convex side drain valve 18 and allowing the steam to flow into the mold 4;
(B) Next, the concave side pressure regulating steam valve 12 and the convex side drain valve 18 are opened, and the convex side pressure regulating steam valve 17 and the concave side drain valve 13 are closed and the concave mold 2 side is shifted to the convex mold 3 side, or Opening the convex pressure regulating steam valve 17 and the concave drain valve 13, closing the concave pressure regulating steam valve 12 and the convex drain valve 18, and allowing the steam to flow from the convex 3 side to the concave 2 side while heating,
(C) Next, the convex side pressure regulating steam valve 17 is opened, the concave side pressure regulating steam valve 12 is closed, and the convex side is opened from the convex mold 3 side, or the concave side pressure regulating steam valve 12 is opened. A reverse heating process in which the pressure regulating steam valve 17 is closed and the steam flows from the concave mold 2 side to the convex mold 3 side;
(D) Next, a double-sided heating step in which the concave side pressure regulating steam valve 12 and the convex side pressure regulating steam valve 17 are opened, the concave side drain valve 13 and the convex side drain valve 18 are closed, and the mold 4 is heated.
(E) Next, the concave-side pressure regulating steam valve 12, the convex-side pressure regulating steam valve 17, the concave-side drain valve 13 and the convex-side drain valve 18 are closed, and the inside of the mold 4 is kept warm with the retained steam. Heat retention process,
I do.

Furthermore, after the end of the (e) heat retention step,
(F) A water cooling step of opening the cooling water valves 15 and 20 to introduce cooling water into the molding apparatus 1 and flowing it toward the concave mold 2 and the convex mold 3 to cool the mold,
(G) After the water cooling step, the concave side drain valve 13, the convex side drain valve 18, the cooling water valves 15 and 20 are closed, and the vacuum valves 14 and 19 are opened to evacuate the inside of the molding die 4. And a cooling process for cooling the convex mold 3,
I do.

After standing to cool, the concave mold 2 and the convex mold 3 are moved away from each other to open the mold, and the foam molded body obtained by in-mold foam molding is taken out.
Thereafter, the mold is closed again, pre-expanded particles are filled into the cavity 9, and the above steps are repeated.

[Comparative example]
In the comparative example, a polystyrene-based resin foam molded article was manufactured using a molding apparatus in which a heat insulating layer was not provided on the outer surface of the mold.
As the molding apparatus, AD1313 manufactured by Kasahara Kogyo Co., Ltd. was used. A concave mold and a convex mold capable of molding a square box-shaped fish box having an outer dimension of 480 mm × 310 mm × 120 mm) and an inner dimension of 435 mm × 265 mm × 100 mm) were attached to this molding apparatus.
After closing the mold, polystyrene resin pre-expanded particles were filled in the cavity. As the pre-expanded particles, HDMF (bulk expansion ratio 60 times) manufactured by Sekisui Plastics Co., Ltd. was used.
Next, 0.065 MPa of steam was introduced into the molding die 4 from the concave side pressure regulating steam valve 12 and the convex side pressure regulating steam valve 17, and the respective heating steps (a) to (e) were continuously performed. .

(A) a mold heating step of opening the concave side pressure regulating steam valve 12, the convex side pressure regulating steam valve 17, the concave side drain valve 13 and the convex side drain valve 18 and allowing the steam to flow into the mold 4;
(B) Next, the concave side pressure regulating steam valve 12 and the convex side drain valve 18 are opened, the concave side drain valve 13 and the convex side pressure regulating steam valve 17 are closed, and the steam is transferred from the concave mold 2 side to the convex mold 3 side. While heating process,
(C) Next, the convex side pressure regulating steam valve 17 and the concave side drain valve 13 are opened, the concave side pressure regulating steam valve 12 and the convex side drain valve 18 are closed, and the steam is transferred from the convex type 3 side to the concave type 2 side. Reverse one-side heating process,
(D) Next, a double-sided heating step in which the concave side pressure regulating steam valve 12 and the convex side pressure regulating steam valve 17 are opened, the concave side drain valve 13 and the convex side drain valve 18 are closed, and the mold 4 is heated.
(E) Next, the concave-side pressure regulating steam valve 12, the convex-side pressure regulating steam valve 17, the concave-side drain valve 13 and the convex-side drain valve 18 are closed, and the inside of the mold 4 is kept warm with the retained steam. Thermal insulation process.

(F) A water cooling step of cooling the mold with cooling water after the heat retaining step (e),
(G) Next, a cooling step,
After that, the mold was opened to obtain a fish box.
About the fish box obtained in this comparative example, as a result of investigating the quality as a foam-molded product by appearance inspection and internal fusion inspection, the quality was good (◯).
Table 1 shows the time required for each process, the total heating time, the amount of steam per shot, and the fuel consumption rate (at the time of molding) in this comparative example.

[Example 1]
As in the first example of the heat insulating layer shown in FIG. 2, an adhesive layer using a silicone resin adhesive (trade name “modified silicone HM-NEW” manufactured by Sekisui Fuller) on the outer surface of the frame 6 of the mold 4. A heat-insulating sheet 32 having a thickness of 2.0 mm (manufactured by Kikuchi Sheet Industry Co., Ltd., trade name “single-sided aluminum laminated heat-resistant felt”) was bonded through 33. A heat insulating layer 34 was formed by the adhesive layer 33 and the heat insulating sheet 32. Using the molding apparatus provided with the heat insulating layer 34, the time required for each of the steps (a) to (g) in Comparative Example 1 was changed as shown in Table 1, and a fish box made of polystyrene resin foam molded body was used. Manufactured.
At this time, the aluminum layer 32a of the heat insulating sheet 32 was bonded toward the adhesive layer 33 side (frame 6 side).
The thermal conductivity, thickness, and thermal resistance value of the used (1) heat insulating sheet 32, (2) the adhesive layer 33, and (3) the heat insulating layer 34 formed by laminating them are as follows.

(1) Thermal insulation sheet Thermal conductivity (λ) = 0.0143 W / (m · K)
Thickness (d) = 0.002m (= 2.0mm)
Thermal resistance value (R) = 0.140 m ² · K / W
(2) Adhesive layer Thermal conductivity (λ) = 0.90 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance (R) = 0.003m ² · K / W
(3) Thermal insulation layer (total of (1) and (2) above)
Thickness (d) = 0.005m (= 5.0mm)
Thermal resistance value (R) = 0.143m ² · K / W

The quality of the fish box obtained in Example 1 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 1.

[Example 2]
Similar to the second example of the heat insulating layer shown in FIG. 3, an adhesive layer using a silicone resin adhesive (trade name “modified silicone HM-NEW” manufactured by Sekisui Fuller) on the outer surface of the frame 6 of the mold 4. A heat insulating sheet 32 (made by Kikuchi Sheet Industry Co., Ltd., trade name “single-sided aluminum laminated heat-resistant felt”) having a thickness of 2.0 mm was bonded through 33, and a coating film 35 of heat insulating paint was laminated on the outer surface. A heat insulating layer 36 was formed by the adhesive layer 33, the heat insulating sheet 32, and the heat insulating coating film 35. Using the molding apparatus provided with the heat insulating layer 36, the time required for each step (a) to (g) in Comparative Example 1 was changed as shown in Table 1, and a fish box made of polystyrene resin foam molded body Manufactured.
At this time, the aluminum layer 32a of the heat insulating sheet 32 was bonded toward the adhesive layer 33 side (frame 6 side).
Used coating film 35 of (1) heat insulating sheet 32, (2) adhesive layer 33, (3) heat insulating paint containing non-crystalline silica (manufactured by Nippon Telenics, trade name “Ceramic Cover CC100”), and these (4) The thermal conductivity, thickness, and thermal resistance value of the heat insulating layer 36 are as follows.

(1) Thermal insulation sheet Thermal conductivity (λ) = 0.0143 W / (m · K)
Thickness (d) = 0.002m (= 2.0mm)
Thermal resistance value (R) = 0.140 m ² · K / W
(2) Adhesive layer Thermal conductivity (λ) = 0.90 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance (R) = 0.003m ² · K / W
(3) Thermal insulating coating film Thermal conductivity (λ) = 0.0185 W / (m · K)
Thickness (d) = 0.001m (= 1.0mm)
Thermal resistance value (R) = 0.054m ² · K / W
(4) Thermal insulation layer (total of (1), (2) and (3) above)
Thickness (d) = 0.0065m (= 6.0mm)
Thermal resistance value (R) = 0.197m ² · K / W

The quality of the fish box obtained in Example 2 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 2.

[Example 3]
As in the third example of the heat insulating layer shown in FIG. 4, an adhesive layer using a silicone resin adhesive (trade name “modified silicone HM-NEW” manufactured by Sekisui Fuller) on the outer surface of the frame 6 of the mold 4. Glass wool 37 (trade name “Glaslon Wool GW32” manufactured by Asahi Fiber Glass Co., Ltd., density 32 kg / m ³ , thickness 25 mm) was bonded through 33. A heat insulating layer 38 was formed by the adhesive layer 33 and the glass wool 37. Using the molding apparatus provided with the heat insulating layer 38, the time required for each step (a) to (g) in Comparative Example 1 was changed as shown in Table 1, and a fish box made of polystyrene resin foam molded body Manufactured.
The thermal conductivity, thickness, and thermal resistance value of the used (1) glass wool 37, (2) the adhesive layer 33, and (3) the heat insulating layer 38 formed by laminating them are as follows.

(1) Glass wool Thermal conductivity (λ) = 0.046 W / (m · K)
Thickness (d) = 0.025m (= 25.0mm)
Thermal resistance (R) = 0.543m ² · K / W
(2) Adhesive layer Thermal conductivity (λ) = 0.90 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance (R) = 0.003m ² · K / W
(3) Thermal insulation layer (total of (1) and (2) above)
Thickness (d) = 0.028m (= 28.0mm)
Thermal resistance value (R) = 0.546m ² · K / W

The quality of the fish box obtained in Example 3 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 3.

[Example 4]
A heat insulating layer 38 was formed in the same manner as in Example 3 except that the glass wool of Example 3 was changed to rock wool felt (trade name “Felt N” manufactured by NICHIAS Corporation, density 40 kg / m ³ , thickness 25 mm). And using the shaping | molding apparatus which provided the heat insulation layer 38, the required time of each process of said (a)-(g) in the comparative example 1 was changed as shown in Table 1, and the product made from a polystyrene-type resin foam molding is used. A fish box was manufactured.
The thermal conductivity, thickness, and thermal resistance value of the used (1) rock wool felt 37, (2) the adhesive layer 33, and (3) the heat insulating layer 38 formed by laminating them are as follows.

(1) Rock wool felt Thermal conductivity (λ) = 0.049 W / (m · K)
Thickness (d) = 0.025m (= 25.0mm)
Thermal resistance value (R) = 0.510 m ² · K / W
(2) Adhesive layer Thermal conductivity (λ) = 0.90 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance (R) = 0.003m ² · K / W
(3) Thermal insulation layer (total of (1) and (2) above)
Thickness (d) = 0.028m (= 28.0mm)
Thermal resistance value (R) = 0.513 m ² · K / W

The quality of the fish box obtained in Example 4 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 4.

[Example 5]
A heat insulating layer 38 was formed in the same manner as in Example 3 except that the glass wool of Example 3 was changed to a calcium silicate plate (trade name “Chiyoda Sera Board” manufactured by Chiyoda Sera, density 0.6 g / cm ³ , thickness 5 mm). Formed. And using the shaping | molding apparatus which provided the heat insulation layer 38, the required time of each process of said (a)-(g) in the comparative example 1 was changed as shown in Table 1, and the product made from a polystyrene-type resin foam molding is used. A fish box was manufactured.
The thermal conductivity, thickness, and thermal resistance value of the used (1) calcium silicate plate 37, (2) the adhesive layer 33, and (3) the heat insulating layer 38 formed by laminating them are as follows. .

(1) Calcium silicate plate Thermal conductivity (λ) = 0.18 W / (m · K)
Thickness (d) = 0.005m (= 5.0mm)
Thermal resistance value (R) = 0.028 m ² · K / W
(2) Adhesive layer Thermal conductivity (λ) = 0.90 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance (R) = 0.003m ² · K / W
(3) Thermal insulation layer (total of (1) and (2) above)
Thickness (d) = 0.008m (= 8.0mm)
Thermal resistance value (R) = 0.031 m ² · K / W

The quality of the fish box obtained in this Example 5 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 5.

[Example 6]
A heat insulating layer 38 was formed in the same manner as in Example 3 except that the glass wool of Example 3 was changed to a non-asbestos joint sheet (trade name “V / 6500 packing” manufactured by VALQUA Japan, density 18 kg / cm ² , thickness 3 mm). Formed. And using the shaping | molding apparatus which provided the heat insulation layer 38, the required time of each process of said (a)-(g) in the comparative example 1 was changed as shown in Table 1, and the product made from a polystyrene-type resin foam molding is used. A fish box was manufactured.
The thermal conductivity, thickness, and thermal resistance value of the used (1) non-asbestos joint sheet 37, (2) the adhesive layer 33, and (3) the heat insulating layer 38 obtained by laminating them are as follows. .

(1) Non-ass joint sheet thermal conductivity (λ) = 0.22 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance value (R) = 0.014 m ² · K / W
(2) Adhesive layer Thermal conductivity (λ) = 0.90 W / (m · K)
Thickness (d) = 0.003m (= 3.0mm)
Thermal resistance (R) = 0.003m ² · K / W
(3) Thermal insulation layer (total of (1) and (2) above)
Thickness (d) = 0.006m (= 6.0mm)
Thermal resistance value (R) = 0.017m ² · K / W

The quality of the fish box obtained in Example 6 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 6.

[Example 7]
Similar to the fourth example of the heat insulating layer shown in FIG. 5, a molding apparatus in which a heat insulating layer 35a made of a heat insulating paint film 35 containing ceramic hollow beads or the like is provided on the entire outer surface of the frame 6 of the mold 4 is compared. The time required for each of the steps (a) to (g) in Example 1 was changed as shown in Table 1, to produce a fish box made of polystyrene resin foam.
For the heat insulating layer, a heat insulating paint containing amorphous silica (manufactured by Nippon Telenics Co., Ltd., trade name “Ceramic Cover CC100”) is applied to the entire outer surface of the mold frame so that the film thickness after drying is 1.5 mm. , Dried to form.
Thermal conductivity (λ) of the formed heat insulating layer = 0.0185 W / (m · K) (= 0.159 kcal / mh ° C.),
Thickness (d) = 0.015 m (= 1.5 mm),
Thermal resistance value (R) = 0.081 m ² · K / W,
Met.
The quality of the fish box obtained in Example 7 was good (◯).
Table 1 shows the time required for each process, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 7.

[Example 8]
As in the fifth example of the heat insulating layer shown in FIG. 6, in addition to the entire outer surface of the frame 6 of the mold 4, the heat insulating paint containing ceramic hollow beads etc. on the entire outer surface of the bracket side back plate 8 a and the entire outer surface of the die plate 8 b. The heat insulation layer 35a consisting of the coating film 35 was formed. Using the molding apparatus provided with the heat insulating layer 35a, the time required for each step (a) to (g) in Comparative Example 1 was changed as shown in Table 1, and a fish box made of polystyrene resin foam molded body Manufactured.
The heat conductivity, thickness, and thermal resistance value of the heat insulating layer are the same as those of the heat insulating layer of Example 7.
The quality of the fish box obtained in Example 8 was good (◯).
Table 1 shows the time required for each step, the total heating time, the amount of steam per shot, the fuel consumption rate (during molding), and the thermal resistance value in Example 8.

From the results shown in Table 1, a heat insulating layer is formed over the entire outer surface of the frame 6 of the mold 4 or the entire outer surface of the frame 6 of the mold 4 as well as the entire outer surface of the bracket-side back plate 8a and the outer surface of the die plate 8b. When the molds of Examples 1 to 8 according to the invention are used, the amount of steam per shot can be reduced and the time required for the molding cycle can be reduced as compared with the mold of the comparative example in which the heat insulating layer is not provided. I was able to.
In the molds of Examples 1 to 8, the heat insulating layer was observed at the end of continuous production of about 20 shots. As a result, no signs of peeling or deterioration were observed in any of the heat insulating layers.
The mold using glass wool as the heat insulation layer of Example 3 and the mold using rock wool felt as the heat insulation layer of Example 4 are likely to cause trouble in the molding operation because the heat insulation layer is thick and the mold 4 is bulky. was there. Further, steam and water during molding may enter the inside of glass wool or rock wool felt, which may change the heat resistance value of the heat insulating layer.

<Measurement of flame temperature change>
In the molding apparatus shown in FIG. 1, temperature detectors are arranged in the upper temperature measuring unit 30 and the lower temperature measuring unit 31 of the frame 6, and a fish box is manufactured using the molds of the comparative example and Examples 1 to 8. The flame temperature was measured. In addition, the measurement of flame | frame temperature measured the highest temperature at the time of the one heating process of the 20th shot from the start of continuous production of a fish box. The results are shown in Table 2.

  From the results of Table 2, when the molds of Examples 1 to 8 according to the present invention were used, the frame temperature was lower than that of the comparative mold having no heat insulating layer.

  The present invention relates to an in-mold foam-molding mold for producing a thermoplastic resin foam-molded article such as a polystyrene-based resin foam-molded article by in-mold foam molding and an in-mold foam molding apparatus equipped with the same, and in particular, the amount of steam used as a heating medium The present invention relates to an in-mold foam-molding mold and an in-mold foam-molding apparatus capable of reducing the amount of the conventional method.

  DESCRIPTION OF SYMBOLS 1 ... Molding apparatus, 2 ... Concave mold, 3 ... Convex mold, 4 ... Mold, 5 ... Concave body, 6 ... Frame, 7 ... Convex body, 8a ..., 8b ..., 9 ... Cavity, 10, 11 ... Steam chamber , 12 ... concave side pressure regulating steam valve, 13 ... concave side drain valve, 14, 19 ... vacuum valve, 15, 20 ... cooling water valve, 16, 21 ... pressure gauge, 17 ... convex side pressure regulating steam valve, 18 DESCRIPTION OF SYMBOLS ... Convex side drain valve, 30 ... Upper temperature measurement part, 31 ... Lower temperature measurement part, 32 ... Heat insulation sheet, 32a ... Aluminum layer, 33 ... Adhesive layer, 34 ... Heat insulation layer, 35 ... Coating film of heat insulation paint, 35a ... heat insulation layer, 36 ... heat insulation layer, 37 ... glass wool, 38 ... heat insulation layer.

Claims (8)

A first mold having a hollow steam chamber composed of a frame, a bracket-side back plate, and a first mold body provided with a plurality of steam holes, a frame, a die plate, and a plurality of steam holes. And a second mold having a hollow steam chamber composed of a second mold body, and pre-foaming foamable thermoplastic resin particles in a cavity formed by combining the first and second mold bodies. In the foamed resin mold for filling the pre-foamed resin particles formed, contacting the pre-foamed resin particles with the vapor through the plurality of vapor holes, and producing a foamed resin molded product,
A foamed resin mold characterized in that at least a part of the outer surface of the frame of the first mold and the outer surface of the bracket-side back plate and the outer surface of the frame of the second mold and the outer surface of the die plate are covered with a heat insulating layer. ^2. The foamed resin mold according to claim 1, wherein the heat insulating layer has a thermal resistance value (R) in a range of 0.05 to 0.25 m ² · K / W.   The foamed resin mold according to claim 1 or 2, wherein the heat insulating layer has a thickness of 8 mm or less.   The said heat insulation layer contains an aluminum film laminated heat-resistant nonwoven fabric, The foaming resin molding die of any one of Claims 1-3 characterized by the above-mentioned.   The said heat insulation layer contains the coating film of a heat insulation paint, The foaming resin molding die of any one of Claims 1-4 characterized by the above-mentioned.   The foamed resin molding apparatus which has a foamed resin molding die of any one of Claims 1-5.   A method for producing a foamed resin molded product, comprising producing a foamed resin molded product using the foam molding apparatus according to claim 6.   A foamed resin molded product obtained from the method for producing a foamed molded product according to claim 7.

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