JP2020049920A - Manufacturing method of foam molding - Google Patents

Abstract

To improve manufacturability of a foam molding.SOLUTION: A manufacturing method of a foam molding is for manufacturing a plurality of foam moldings 11, and comprises: a first step in which, by using a metal mold 31 comprising a plurality of first spaces 35 for molding a plurality of foam moldings 11, respectively, and a second space 36 for molding a weakened part 21 which connects the plurality of first spaces 35 to each other to couple the plurality of foam moldings 11, prefoamed particles whose average particle diameter is equal to a minimum width L5 or more of the second space 36 are supplied to the plurality of first spaces 35, respectively; and a second step in which a coupled body 20 of the plurality of foam moldings 11 molded in the plurality of first spaces 35, respectively, and the weakened part 21 molded in the second space 36 is released from the metal mold 31, and the weakened part 21 is broken.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for producing a foam molded article.

Some cars have spare tires stored in them. The spare tire is stored in a storage space provided in, for example, a trunk of an automobile. The storage space is provided with a lid for the storage space. Conventionally, as this type of lid, for example, a luggage box and a simple plate-shaped lid as shown in Patent Literature 1 below are known.
As a plate-like lid, the following configuration is generally known. That is, this type of lid includes a plurality of foamed molded bodies formed in a plate shape, a reinforcing member that connects the plurality of foamed molded bodies, and a skin material that covers the plurality of foamed molded bodies and the reinforcing members. Prepare.

  A bead foaming method is known as a method for producing a foamed molded article for producing the foamed molded article. The bead foaming method includes, for example, polymerization, pre-foaming, and molding steps. In the polymerization step, a resin as a raw material is polymerized, and a foaming agent is added to the polymerized resin to produce expandable particles (raw material beads). In the pre-expansion step, the expandable particles are foamed by heating with steam to form pre-expanded particles (expanded beads) having a certain size. In the molding step, the pre-expanded particles are filled in a mold and heated and expanded in the mold by steam. As a result, a foam molded article is formed in the mold. Thereafter, the molded article is released from the mold and, for example, appropriately dried to obtain a desired foam molded article.

FIG. 8 shows an example of a conventional mold 101. The mold 101 includes a first mold 102 (movable mold) and a second mold 103 (fixed mold). A plate 111 is fixed to each of these molds, and the mold 101 and the plate 111 form a molding machine 100.
A plurality of cavities 104 are formed between the first mold 102 and the second mold 103 as a molding space. Each of the plurality of cavities 104 is an independent space. A filling port (not shown) for filling the pre-expanded particles is formed in the first mold 102 corresponding to each cavity 104. Each cavity 104 is filled with pre-expanded particles from a filling port. After filling, steam is introduced into each cavity 104 and the pre-expanded particles in the cavity 104 are heated.

JP 2008-222187 A

  However, in the conventional mold, a plurality of cavities are independently provided, and a structure for sealing between the cavities is adopted. Therefore, an increase in the size of the molding machine including the mold has been inevitable.

  The present invention has been made in view of the circumstances described above, and has as its object to enhance the productivity of a foam molded article.

In order to solve the above problems, the present invention proposes the following means.
(1) A method for manufacturing a foamed molded article according to the present invention is a method for manufacturing a foamed molded article for producing a plurality of foamed molded articles, wherein a plurality of first spaces for molding each of the plurality of foamed molded articles, A second space that connects the plurality of first spaces to each other and forms a weakened portion that connects the plurality of foamed molded articles; and a mean particle diameter in each of the plurality of first spaces. Supplying the pre-expanded particles having a width equal to or larger than the minimum width of the second space, and forming the plurality of foamed molded bodies formed inside each of the plurality of first spaces and the inside of the second space. A second step of releasing the connected body with the weakened portion from the mold and breaking the weakened portion.

  The plurality of first spaces are connected through the second space. Therefore, it is not necessary to provide a plurality of first spaces independently, and it is possible to suppress an increase in the size of the mold and the molding machine. Thereby, for example, it is possible to manufacture a foam molded article even in a narrow space, and the productivity of the foam molded article can be improved.

In the first step, the plurality of first spaces are connected through the second space. Therefore, the temperature environment and the like in each first space can be approximated. Therefore, for example, the physical properties of a plurality of foamed molded articles can be made close to each other. For example, when the same physical properties are required for these foamed molded articles, as a result, the quality of the foamed molded articles can be improved (for example, when the foamed molded articles are plate-shaped, Can be secured equally).
Moreover, in the first step, the pre-expanded particles having an average particle diameter equal to or larger than the minimum width of the second space are supplied to each of the plurality of first spaces. Therefore, a part of the pre-expanded particles supplied to the first space is limitedly supplied to the second space. Therefore, it is possible to suppress the pre-expanded particles supplied into each first space from flowing out excessively from the first space. As a result, the foam molded article molded in each first space can be formed by an appropriate amount of the pre-expanded particles.
As described above, a plurality of foamed molded bodies can be formed in parallel in a mold with high precision.

In the second step, the weakened portion in the connected body is broken. Therefore, it is not necessary to break the weakened portion again, and the productivity can be improved.
In addition, as described above, in the first step, the pre-expanded particles having an average particle diameter equal to or greater than the minimum width of the second space are supplied to each of the plurality of first spaces, so that the first expanded space is supplied to the first space. Part of the pre-expanded particles is limitedly supplied into the second space. Therefore, it is possible to prevent the pre-expanded particles from being excessively supplied into the second space. As a result, the weakened portion can be formed in a state where its strength is appropriately weak. Therefore, the weakened portion can be easily broken in the second step.

(2) In the method for manufacturing a foamed molded article according to the above (1), the foamed molded article is plate-shaped, the plurality of first spaces are arranged in a vertical direction, and each of the plurality of first spaces is provided. In the above, the mold is arranged such that a direction that is a thickness direction of the foam molded body is a first horizontal direction among horizontal directions, and a minimum width of the second space is the same as that of the second space. A configuration having a size in the first horizontal direction may be employed.

  The minimum width of the second space is the size of the second space in the first horizontal direction. Therefore, the minimum width of the weakened portion is the size of the plurality of foamed moldings in the thickness direction. Thereby, the weakened portion can be easily broken in the thickness direction.

(3) In the method for manufacturing a foamed molded article according to the above (2), a configuration may be employed in which the second space is recessed from both sides in the first horizontal direction with respect to the first space.

  The second space is recessed from both sides in the first horizontal direction with respect to the first space. Therefore, in the connected body, the weakened portion is depressed from both sides in the thickness direction of the foam molded body with respect to the foam molded body. Thereby, the weakened portion can be more easily broken.

(4) In the method for manufacturing a foamed molded article according to the above (2) or (3), the second space is a second direction orthogonal to the first horizontal direction in the horizontal direction for each of the plurality of first spaces. A configuration extending over the entire length in the horizontal direction may be adopted.

  The second space extends over the entire length in the second horizontal direction for each of the plurality of first spaces. Therefore, the temperature environment and the like in each first space can be more approximated.

(5) In the method of manufacturing a foamed molded article according to the above (1) to (4), in the second step, the plurality of foamed molded articles are each separated from the mold by a release pin provided on the mold. May be adopted.

  In the second step, each of the plurality of foam molded articles is released from the mold by a release pin. Therefore, for example, by making the release timing of each foam molded body different by the release pin, each foam molded body can be relatively displaced, and the weakened portion can be deformed. As a result, the weakened portion can be broken in parallel with releasing the plurality of foamed molded products from the mold.

  ADVANTAGE OF THE INVENTION According to this invention, the productivity of a foaming molding can be improved.

It is a top view showing the lid provided with the foaming fabrication object manufactured by the manufacturing method of the foaming fabrication object concerning one embodiment of the present invention. FIG. 2 is a sectional view taken along the line II-II shown in FIG. 1. FIG. 2 is a cross-sectional view illustrating a connected body including the foam molded body illustrated in FIG. 1. It is a figure explaining the manufacturing method which manufactures the foaming molding shown in FIG. 1, and is sectional drawing which shows the state which opened the metal mold | die before molding the foaming molding. FIG. 5 is a cross-sectional view illustrating a state in which the foam molded article is molded in a mold, illustrating a method for producing the foam molded article illustrated in FIG. 1. FIG. 2 is a cross-sectional view illustrating a manufacturing method for manufacturing the foamed molded article illustrated in FIG. 1, and illustrates a state where a mold is opened after molding the foamed molded article. It is a figure explaining the manufacturing method which manufactures the foaming molding shown in FIG. 1, and is sectional drawing which shows the state which released the foaming molding from the metal mold | die. It is sectional drawing explaining the conventional metal mold | die.

  Hereinafter, with reference to FIGS. 1 to 7, a method of manufacturing a foam molded article according to an embodiment of the present invention will be described. Before describing the method for manufacturing a foam molded article, first, the lid 10 including the foam molded article 11 produced by this method will be described.

  A lid 10 as shown in FIG. 1 is used for a trunk of an automobile. The lid 10 closes a storage space for a spare tire provided in the trunk. The lid 10 also functions as a floor of the trunk. The lid 10 includes a plurality of foamed molded bodies 11 formed in a plate shape, a reinforcing member 12 that connects the plurality of foamed molded bodies 11, and a skin material 13 that covers the plurality of foamed molded bodies 11 and the reinforcing members 12. , Is provided.

  As shown in FIGS. 1 and 2, the foam molded body 11 is formed of a rigid foam such as styrene foam. Two foam moldings 11 are provided. Each of the two foam molded bodies 11 is formed in a flat plate shape. The thickness directions T of the two foamed molded bodies 11 are parallel to each other. The two foam molded bodies 11 are arranged side by side in a first direction D1 orthogonal to the plate thickness direction T. A direction orthogonal to both the plate thickness direction T and the first direction D1 is defined as a second direction D2. Each foamed body 11 is longer in the second direction D2 than in the first direction D1.

  The ends of the foamed moldings 11 facing each other in the first direction D1 are straight ends 14. The straight end 14 extends linearly in the second direction D2. The lengths of the straight ends 14 of the plurality of foamed moldings 11 are equal to each other. Each linear end 14 is provided with a protrusion 15. The protruding portions 15 of each foam molded body 11 face each other in the first direction D1. The protrusion 15 extends along the entire length in the second direction D2 along the straight end 14. The size of the protrusion 15 in the thickness direction T is smaller than the size of the straight end portion 14 in the thickness direction T. The protruding portions 15 are recessed from both sides in the plate thickness direction T with respect to the straight end portion 14. The protrusion amount L1 (the size in the first direction D1) of the protrusion 15 is larger than the thickness L2 (the size in the plate thickness direction T) of the protrusion 15.

The reinforcing member 12 is formed of a metal (light metal) such as aluminum. The reinforcing member 12 extends linearly in the second direction D2. The cross-sectional shape of the reinforcing member 12 is H-shaped. The protruding portion 15 is fitted into each recess 12 a of the reinforcing member 12.
The outer skin material 13 is formed of, for example, a resin such as a hard plastic. The skin material 13 is provided in a pair with the foam molded body 11 and the reinforcing member 12 interposed in the plate thickness direction T. Each skin material 13 covers the whole of the plurality of foam molded bodies 11 and the reinforcing members 12 in plan view. The pair of outer cover members 13 are connected to each other at their outer peripheral edges. As a result, the plurality of foamed molded bodies 11 and the reinforcing members 12 are accommodated between the pair of outer cover members 13.

Next, the connecting body 20 formed in the process of manufacturing the foam molded body 11 will be described.
As shown in FIG. 3, the connecting body 20 includes a plurality of foam molded bodies 11 and a weakened portion 21 that connects these foam molded bodies 11.

  One connection body 20 includes all the foam molded bodies 11 provided in one lid 10. In the illustrated example, one connection body 20 includes two foam molded bodies 11. In the connector 20, the posture of each foam molded body 11 is the same as the posture when each foam molded body 11 is used as the lid 10. That is, the thickness direction T of each foam molded body 11 is parallel, each foam molded body 11 is arranged side by side in the first direction D1, and each straight end portion 14 and each protrusion 15 are formed in the second direction D2. Extends to. In addition, the protruding portions 15 of each foam molded body 11 face each other with an interval in the first direction D1.

  The weakened portion 21 connects the protruding portions 15 of each foam molded body 11 to each other. The weakened portion 21 is provided over the entire length of the protruding portion 15 in the second direction D2. The weakened portion 21 may be provided intermittently over the entire length in the second direction D2, or may be provided continuously over the entire length in the second direction D2.

  The weakened portion 21 is recessed from both sides in the plate thickness direction T with respect to the protruding portion 15. The size L3 of the weakened portion 21 in the first direction D1 may be larger or smaller than the size L4 of the weakened portion 21 in the thickness direction T. The size L3 of the weakened portion 21 in the first direction D1 may be equal to the size L4 of the weakened portion 21 in the thickness direction T. The size L3 of the weakened portion 21 in the first direction D1 and the size L4 of the weakened portion 21 in the thickness direction T are both smaller than the protrusion amount L1 of the protrusion 15 and the thickness L2 of the protrusion 15.

Next, the molding machine 30 for molding the connecting body 20 will be described.
As shown in FIGS. 4 to 7, the molding machine 30 includes a mold 31 for molding the connected body 20, a plate 41 for supporting the mold 31, and a release pin for releasing the connected body 20 from the mold 31. 42.
The mold 31 includes a first mold 32 and a second mold 33. The first mold 32 is a movable mold, and the second mold 33 is a fixed mold. A cavity 34 is formed between the first mold 32 and the second mold 33. The cavity 34 includes a plurality of first spaces 35 and a second space 36 connecting the first spaces 35.

  The plurality of first spaces 35 form each of the plurality of foam molded bodies 11. The second space 36 forms the weakened portion 21. The plurality of first spaces 35 are arranged in the vertical direction V. That is, the mold 31 is arranged such that the first direction D1 in the above-described connector 20 is the vertical direction V. In each of the plurality of first spaces 35, the direction that becomes the plate thickness direction T of the foam molded body 11 is the first horizontal direction H1 of the horizontal directions. In other words, the direction that becomes the second direction D2 of the connector 20 in each of the plurality of first spaces 35 is the second horizontal direction H2 that is orthogonal to the first horizontal direction H1 of the horizontal directions. The plurality of first spaces 35 have the same size in the second horizontal direction H2.

  The second space 36 extends over the entire length of the plurality of first spaces 35 in the second horizontal direction H2. The second space 36 is recessed from the first space 35 from both sides in the first horizontal direction H1. The minimum width of the second space 36 is the size L5 of the second space 36 in the first horizontal direction H1. The size L5 of the second space 36 in the first horizontal direction H1 may be larger or smaller than the size L6 of the second space 36 in the vertical direction V. The size L5 of the second space 36 in the first horizontal direction H1 may be equal to the size L6 of the second space 36 in the vertical direction V.

  The first mold 32 and the second mold 33 relatively close to and separate from each other in the first horizontal direction H1, and are opened and closed. In the present embodiment, the first mold 32 moves in the first horizontal direction H1 with respect to the second mold 33. In the first mold 32, a concave portion 34a for the cavity 34 which is to be the above-described cavity 34 is formed. The concave portion 34a becomes the cavity 34 by being closed by the second mold 33 when the mold 31 is closed.

Next, a method for producing the foam molded article will be described.
First, a polymerization step and a pre-expansion step are performed to form pre-expanded particles.
Thereafter, a molding step is performed. In this molding step, first, a first step of supplying the pre-expanded particles into each of the plurality of first spaces 35 of the mold 31 is performed. The pre-expanded particles are supplied, for example, from a filling port (not shown) that opens into each first space 35. At this time, in this embodiment, pre-expanded particles having an average particle diameter equal to or larger than the minimum width of the second space 36 are supplied as the pre-expanded particles.

The average particle diameter of the pre-expanded particles can be measured, for example, by the following method.
That is, the particle size distribution of the pre-expanded particles after the pre-expansion step is measured, and the particle diameter (the so-called mode diameter) corresponding to the mode in the distribution can be set as the average particle diameter.
As a more specific example, first, the pre-expanded particles after the pre-expansion step are randomly weighed and extracted, and are put into a sieve net (sieve net). At this time, the pre-expanded particles are basically weighed in an amount of about 50 g (about one cup of a 200 mL polybeaker heap). Further, the range of the openings of the sieve mesh is, for example, 0.5 mm to 5.6 mm, and the unit of the openings is about 0.3 mm to 0.6 mm.
Then, the pre-expanded particles put in the sieve net (sieve net) are separated for a certain period of time (for example, 8 minutes) by a sieve shaker (sieve shaker), and the particle size distribution is measured. As a result, the separation range in which the particles are separated most is defined as the average particle diameter. In this case, the expression that the average particle diameter of the pre-expanded particles is equal to or larger than the minimum width of the second space 36 means that the lower limit value of the separation range is equal to or larger than the minimum width of the second space 36.

After filling the pre-expanded particles, the expanded body is heated by steam and further expanded, and as shown in FIG.
Next, a second step of releasing the connecting body 20 from the mold 31 and breaking the weakened portion 21 is performed. At this time, as shown in FIG. 6, after the mold 31 is opened, as shown in FIG. 7, each of the plurality of foam molded bodies 11 is released from the mold 31 by the release pins 42. The timing at which the release pin 42 comes into contact with each foam molded body 11 may be different for each foam molded body 11. In this case, each weakened portion 21 can be deformed by relatively displacing each foam molded body 11. As a result, the weakened portion 21 can be broken in parallel with releasing the plurality of foam molded bodies 11 from the mold 31.

Further, even if the weakened portion 21 does not break when the mold is released, the weakened portion 21 can be broken by an impact received when the connecting body 20 falls. In addition, even when the connecting body 20 falls on the cushion material arranged below the mold 31, the weakened portion 21 can be broken by the impact.
Even if the weakened portion 21 is broken in any of the above-described forms, a broken piece 21a remains in each foamed molded body 11.

  As described above, according to the method for manufacturing a foam molded article according to the present embodiment, the plurality of first spaces 35 are connected through the second spaces 36. Therefore, it is not necessary to provide the plurality of first spaces 35 independently, and it is possible to suppress an increase in the size of the mold 31 and the molding machine 30. Thereby, for example, it is possible to manufacture the foamed molded body 11 even in a narrow space, and the productivity of the foamed molded body 11 can be improved.

In the first step, a plurality of first spaces 35 are connected through a second space 36. Therefore, the temperature environment and the like in each first space 35 can be approximated. Therefore, for example, the physical properties of the plurality of foamed molded bodies 11 can be made close to each other. For example, when the same physical properties are required for these foamed molded articles 11, as a result, the quality of the foamed molded articles 11 can be improved (for example, as in the present embodiment, the foamed molded articles 11 In the case of (1), the flatness of each foam molded body 11 can be equally secured.)
Moreover, in the first step, the pre-expanded particles having an average particle diameter equal to or larger than the minimum width of the second space 36 are supplied into each of the plurality of first spaces 35. Therefore, a part of the pre-expanded particles supplied into the first space 35 is limitedly supplied into the second space 36. Therefore, it is possible to suppress the pre-expanded particles supplied into each first space 35 from flowing out excessively from the first space 35. As a result, the foam molded body 11 molded in each first space 35 can be formed by an appropriate amount of the pre-expanded particles.
As described above, the plurality of foamed molded bodies 11 can be formed with high precision in the mold 31 in parallel.

In the second step, the weakened portion 21 of the connecting body 20 is broken. Therefore, there is no need to break the weakened portion 21 again, and the productivity can be improved.
In addition, as described above, in the first step, the pre-expanded particles having an average particle diameter equal to or larger than the minimum width of the second space 36 are supplied to each of the plurality of first spaces 35, so that A part of the supplied pre-expanded particles is limitedly supplied to the second space 36. Therefore, excessive supply of the pre-expanded particles into the second space 36 can be suppressed. As a result, the weakened portion 21 can be formed in a state where its strength is appropriately weak. Therefore, the weakened portion 21 can be easily broken in the second step.

The minimum width of the second space 36 is the size of the second space 36 in the first horizontal direction H1. Therefore, the minimum width of the weakened portion 21 is the size of the plurality of foamed molded bodies 11 in the thickness direction T. Thereby, the weakened portion 21 can be easily broken in the plate thickness direction T.
The second space 36 is recessed with respect to the first space 35 from both sides in the first horizontal direction H1. Therefore, in the connecting body 20, the weakened portion 21 is depressed with respect to the foam molded body 11 from both sides in the thickness direction T of the foam molded body 11. Thereby, the weakened portion 21 can be more easily broken.
The second space 36 extends over the entire length of the plurality of first spaces 35 in the second horizontal direction H2. Therefore, the temperature environment and the like in each first space 35 can be more approximated.

  Note that the technical scope of the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention.

  In the above embodiment, one mold 31 includes two first spaces 35 and two foam molded bodies 11 are formed in parallel, but the present invention is not limited to this. For example, one mold 31 may include three or more first spaces 35, and three or more foamed molded bodies 11 may be formed in parallel. In this case, all of the three or more first spaces 35 may be connected through the second space 36. In this case, among the three or more first spaces 35, for example, some of the plurality of first spaces 35 (hereinafter, referred to as a first group of first spaces 35) are connected through one second space 36, and The remaining part of the first space 35 (hereinafter, referred to as a second group of first spaces 35) is connected through another second space 36, while the first group of first spaces 35 and the second group of first spaces 35 are connected. The space 35 and the space 35 may be independent of each other.

In the above-described embodiment, the foam molded body 11 is used for the lid 10 of the spare tire storage space in the trunk of an automobile, but the use of the foam molded body 11 is not limited to this.
The foam molding 11 may not have the protrusion 15.
The connection body 20 may include the foam molded body 11 used for different products.

  In addition, without departing from the spirit of the present invention, it is possible to appropriately replace the components in the above-described embodiment with known components, and the above-described modifications may be appropriately combined.

11 foam molded body 20 connecting body 21 weakened part 31 mold 35 first space 36 second space 42 release pin H1 first horizontal direction H2 second horizontal direction V vertical direction

Claims (5)

A method for producing a foam molded article for producing a plurality of foam molded articles,
A metal comprising: a plurality of first spaces for molding each of the plurality of foamed molded bodies; and a second space for connecting the plurality of first spaces and forming a weakened portion connecting the plurality of foamed molded bodies. A first step of using a mold to supply pre-expanded particles having an average particle diameter equal to or greater than the minimum width of the second space to each of the plurality of first spaces;
A connecting body of the plurality of foamed molded bodies formed inside each of the plurality of first spaces and the weakened portion formed inside the second space is released from the mold to form the weakened portion. And a second step of breaking the foam. The foam molded article is in a plate shape,
The plurality of first spaces are arranged in a vertical direction, and in each of the plurality of first spaces, a direction that is a thickness direction of the foam molded body is a first horizontal direction among horizontal directions. The mold is arranged,
The method according to claim 1, wherein a minimum width of the second space is a size of the second space in the first horizontal direction.   The method for manufacturing a foam molded article according to claim 2, wherein the second space is recessed from both sides in the first horizontal direction with respect to the first space.   4. The production of the foam molded article according to claim 2, wherein the second space extends over a total length in a second horizontal direction orthogonal to the first horizontal direction in the horizontal direction for each of the plurality of first spaces. 5. Method.   5. The foam molded article according to claim 1, wherein in the second step, each of the plurality of foam molded articles is released from the mold by a release pin provided on the mold. 6. Production method.

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