JP2007276265A - Method for producing hollow molding by rotational molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a hollow molding with partition boards which have excellent chemical resistance etc., and high denseness and suppress the occurrence of leakage etc., installed by a rotational molding method. <P>SOLUTION: In a method for producing the hollow molding 1 in which the partition boards 3 and 4 partitioning internal spaces A1, A2, and A3 are installed by the rotational molding method, after partition members 3 and 4 with resin layers 3b and 4b formed on at least the entire surfaces are set in a mold, and their positions are fixed, the mold is heated to heat/melt a powdered thermoplastic resin charged in the mold, and the mold is rotated to make the molten resin adhere to the inner wall surface of the mold to form the wall part 2 of the hollow molding. The resin layers on the surfaces of the partition members are integrated with the molten resin. The partition boards 3 and 4 comprising the partition members and the wall part 2 of the hollow molding are formed integrally to mold the hollow molding 1 with the partition boards 3 and 4 formed inside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a hollow molded body provided with a partition plate for partitioning an internal space by a rotational molding method.

  Conventionally, a hollow molded body made of a thermoplastic resin has been used for applications such as industrial articles, daily goods, automobile parts, electric / electronic parts, machine parts, and the like. These hollow molded bodies are manufactured by, for example, injection molding, blow molding, extrusion molding, or rotational molding.

  Among the molding methods described above, the rotational molding method has advantages that the mold cost is low, the manufacturing cost is low, and a larger molded body can be manufactured.

  By the way, in hollow molded objects, such as a hollow container, in order to partition an internal space, it may be necessary to provide a partition plate. However, a method for producing a hollow molded body having a partition plate by a rotational molding method has not been put into practical use conventionally.

  Patent Document 1 discloses a method of manufacturing a sink container by a rotational molding method. A plate having high heat transfer such as aluminum or stainless steel is used as a partition plate, and a hollow container having the partition plate is rotationally molded. A method of manufacturing by law is disclosed. In addition, Patent Document 1 discloses a method of manufacturing a hollow container by a rotational molding method using a partition plate in which a thermoplastic resin is previously welded to a peripheral portion, placing such a partition plate in a mold. Yes.

  The rotational molding method is a method of manufacturing a hollow molded body by placing a thermoplastic resin powder in a mold and rotating the mold while heating to adhere a molten thermoplastic resin in the mold. However, when the partition plate is provided by the method disclosed in Patent Document 1, the resin is not attached to the partition plate portion, and the surface of the metal plate as the partition plate is exposed. Therefore, there exists a problem that it cannot use for the hollow container in which chemical resistance etc. are calculated | required.

Moreover, in the hollow molded object manufactured by the method of the said patent document 1, the attachment intensity | strength of a partition plate is inadequate, and the problem that a liquid leaks from the attachment part of a partition plate may arise.
JP 59-1114019 A

  An object of the present invention is to provide a method capable of producing a hollow molded body provided with a highly dense partition plate which is excellent in chemical resistance and the like and hardly leaks by a rotational molding method.

  The present invention is a method for producing a hollow molded body provided with a partition plate for partitioning an internal space by a rotational molding method, wherein a partition member provided with a resin layer on at least the entire surface is installed in a mold. After fixing the position, the mold is heated to melt the powdered thermoplastic resin charged in the mold and the mold is rotated to attach the molten resin to the inner wall surface of the mold, In addition to forming the wall portion of the hollow molded body, the resin layer on the surface of the partition member and the molten resin are integrated, and the partition plate made of the partition member and the wall portion of the hollow molded body are integrally formed inside. A hollow molded body provided with a partition plate is molded.

  A more specific embodiment of the present invention is a method for producing a hollow molded body provided with a partition plate for partitioning an internal space by a rotational molding method, and a partition member provided with a resin layer on at least the entire surface is prepared. A step of installing the partition member in the mold and fixing the position thereof, and before or after the partition member is installed in the mold, a powdered thermoplastic resin is put into the mold Process, heating the mold, heating and melting the powdered thermoplastic resin in the mold, rotating the mold, and adhering the molten resin to the inner wall surface of the mold, so that the wall of the hollow molded body And forming the partition plate made of the partition member and the wall of the hollow molded body integrally, and cooling the mold The mold is removed and the partition plate is integrally formed inside. It is characterized by comprising a step of taking out the hollow molded body.

  According to the present invention, a hollow molded body provided with a partition plate for partitioning the internal space can be easily manufactured by a rotational molding method. The partition plate according to the present invention uses a partition member having at least the entire surface formed of a resin layer, which is installed in a mold, and this partition member is formed when a wall portion of a hollow molded body is formed by a rotational molding method. The partition plate and the wall portion of the hollow body are integrally formed to form a hollow molded body provided with the partition plate therein. Since the resin layer is provided on the entire surface of the partition member, the entire inner surface of the hollow molded body produced according to the present invention is covered with resin, and the hollow molded body having excellent chemical resistance and the like can do. Therefore, it can be used as a hollow container or the like that can store various liquids.

  Moreover, since the resin layer is provided on the entire surface of the partition member, the adhesion between the molded body wall portion and the partition plate is good, and the partition plate portion is unlikely to leak and has a high density. Can be provided.

  In the present invention, the resin layer of the partition member is preferably formed from a thermoplastic resin. In particular, it is preferably formed from the same type of resin as that forming the wall portion of the hollow molded body. For example, when the wall portion of the hollow molded body is formed from polyethylene, the resin layer of the partition member is preferably formed from polyethylene. In this case, the same type of resin may be used, and it is not necessary to use the same resin.

  The partition member in this invention should just be provided with the resin layer at least on the whole surface, and the whole partition member may be formed from resin.

  However, when considering the strength and the like of the partition plate, a partition member is preferably used by using a heat-resistant core material and covering the entire surface of the core material with a resin layer. As the heat-resistant core material, a metal plate such as an aluminum plate or a stainless steel plate is preferably used. However, a ceramic member or a heat-resistant plastic member may be used as the core material.

  When a partition member coated with a resin layer is used, the partition member adheres the powder resin onto the core material by a powder coating method, and then melts the powder resin by heating, so that the surface of the core material A resin layer may be formed thereon. Moreover, the resin layer may be formed on the surface of the core material by immersing the heated core material in the powder resin.

  The thickness of the resin layer is not particularly limited, but is generally in the range of 500 μm to 1500 μm.

  In the hollow molded body of the present invention, the partition plate may be provided so as to completely partition the space on both sides thereof, or may be provided so as to partition part of the space on both sides thereof.

  In the manufacturing method of the present invention, as a method for installing the partition member in the mold, for example, a recess for holding the end of the partition member is formed on the inner wall surface of the mold, and the recess is formed in the recess. By arranging the end of the partition member, there is a method of installing the partition member in the mold and fixing its position. In this case, it is preferable that the position of the partition member in the mold at the time of rotational molding is fixed by being held so that the end of the core material is positioned in the recess of the mold.

  Moreover, it is preferable to attach the cap member which consists of a thermoplastic resin to the edge part of a partition member, and hold | maintain the edge part of a partition member in the recessed part of a metal mold | die via this cap member. Such a cap member is made of a thermoplastic resin, and is preferably formed from the same type of resin as the wall portion of the hollow molded body and the resin layer of the partition member. Therefore, when the wall part of a hollow molded object and the resin layer of a partition member are formed from polyethylene, it is preferable to also form a cap member from polyethylene. However, it is not necessary that they are exactly the same resin, and they may be the same type of resin.

  Since the cap member is also formed from a thermoplastic resin, such a cap member can also be melted during rotation molding and integrated with the wall portion of the hollow molded body and the resin layer of the partition member. Therefore, the partition member can be firmly attached to the wall portion of the hollow molded body. Further, by using the cap member, the resin film thickness at the end of the partition member can be increased, and the partition plate can be more firmly fixed.

  Further, in the case where the mold is formed by combining a plurality of partial molds, a flange portion is formed at the abutting end of the partial mold, and the concave portion of the mold is formed by the flange portions of the partial molds abutting each other. It may be configured.

  According to the method for producing a hollow molded body of the present invention, it is possible to easily produce a hollow molded body provided with a high-density partition plate that is excellent in chemical resistance and the like and hardly leaks by rotational molding. it can.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to the following examples.

  FIG. 1 is a perspective view showing an embodiment of a hollow molded body produced according to the present invention. 2 is a cross-sectional view in the horizontal direction of the hollow molded body 1 shown in FIG. 1, and FIG. 3 is a cross-sectional view in the vertical direction.

  As shown in FIG. 1, the hollow molded body 1 is formed from a wall portion 2, and a corner portion 2 a of the wall portion 2 has a rounded shape. Further, holes 2d and 2e are formed on the upper side surface. These holes 2d and 2e are holes formed by inserting an air valve described later.

  On the periphery of the center portion of the hollow molded body 1, a peripheral convex portion 2b protruding outward is formed. As shown in FIGS. 2 and 3, a partition plate 3 is provided at the position of the peripheral convex portion 2b.

  Moreover, the convex part 2c is formed in the side surface part of the horizontal direction of the wall part 2 at the near side and the back | inner side, respectively. As shown in FIGS. 2 and 3, a partition plate 4 is provided at the position of the convex portion 2c. As shown in FIG. 3, the partition plate 4 has spaces formed above and below, and is provided so as to partition only a part of the internal space.

  As shown in FIGS. 2 and 3, the partition plate 3 partitions the internal space A1 and the internal space A2 of the hollow molded body 1. The partition plate 3 is provided so as to completely partition the internal space A1 and the internal space A2.

  Further, the partition plate 4 partitions the internal space A2 and the internal space A3 of the hollow molded body 1. As described above, the partition plate 4 is provided so as to partition a part of the internal space A2 and the internal space A3. That is, as shown in FIG. 3, the internal space A <b> 2 and the internal space A <b> 3 communicate with each other in the upper part and the lower part of the partition plate 4. 4 is a cross-sectional view taken along line XX ′ shown in FIG. As shown in FIG. 4, spaces are formed above and below the partition plate 4, and the internal spaces A2 and A3 are communicated with each other at this portion.

  As shown in FIG.2 and FIG.3, the metal plate 3a is provided in the partition plate 3, and the resin layer 3b is provided so that the whole surface of the metal plate 3a may be covered. In the present embodiment, an aluminum plate is used as the metal plate 3a.

  Similarly, the partition plate 4 is provided with a metal plate 4a made of an aluminum plate, and a resin layer 4b is provided on the entire surface thereof.

  In the present embodiment, the wall 2, the resin layer 3b, and the resin layer 4b are all formed from a polyethylene resin.

  FIG. 5 is an enlarged cross-sectional view of a portion Y shown in FIG. As shown in FIG. 5, the end portion of the metal plate 3 a inside the partition plate 3 is disposed so as to be located outside the wall portion 2. The peripheral convex part 2b is provided so that the edge part of the metal plate 3a may be covered.

  Further, the resin layer 3 b covering the surface of the metal plate 3 a is formed integrally with the wall portion 2.

  FIG. 6 is a front view showing a rotational molding apparatus 11 for producing the hollow molded body of the above embodiment. As shown in FIG. 6, the mold of the rotary molding apparatus 11 includes an upper mold 15 located above the mold, half molds 13 and 14 located at the center, and a lower mold 12 located below. It is composed of An air valve 17 is inserted into the half mold 13, and an air valve 16 is inserted into the lower mold 12. The entire mold is supported by a support base 18. The mold is provided so that it can be biaxially rotated by a first drive means for rotating the mold in a specific direction and a second rotation drive means for rotating the mold in a direction perpendicular to the specific direction.

  FIG. 7 is a side view showing the mold from the side surface direction. As shown in FIG. 7, an air valve hole 16 a for inserting an air valve 16 is formed in the lower mold 12, and an air valve hole 17 a for inserting an air valve 17 is formed in the half mold 13. Is formed.

  8 and 9 are cross-sectional views showing a state in the mold when a hollow molded body is manufactured using the rotary molding apparatus. 8 is a cross-sectional view taken along the paper surface direction of FIG. 6, and FIG. 9 is a cross-sectional view taken along a direction perpendicular to the paper surface of FIG. 6.

  As shown in FIGS. 8 and 9, a flange 12a is formed above the lower mold 12, and flanges 13a and 14a are formed below the half molds 13 and 14, respectively. Yes. A concave portion 13b is formed in a portion where the flange portion 12a and the flange portion 13a are abutted, and one end portion of the partition member 22 is inserted into the concave portion 13b via a cap member 22c. Moreover, the recessed part 14b is formed in the part by which the flange part 14a and the flange part 12a were faced | matched, and the other end of the partition member 22 is inserted in this recessed part 14b via the cap member 22c.

  10 is an enlarged cross-sectional view of a portion Z shown in FIG. As shown in FIG. 10, a recessed portion 13b is formed in the abutting portion of the flange portion 12a of the lower mold 12 and the flange portion 13a of the half mold 13, and the partition member 22 is formed in the recessed portion 13b via a cap member 22c. The other end is inserted.

  Further, as shown in FIG. 9, a flange portion 13 c is formed above the half mold 13, and a concave portion 13 d is formed at the abutting portion with the flange portion 15 a formed below the upper mold 15. Has been. One end and the other end of the partition member 24 are inserted into the recess 13d via the cap member 24c. Although FIG. 9 shows the half mold 13, the half mold 14 is similarly formed with a flange portion, and a recess is formed at the abutting portion with the flange portion 15 a of the upper mold 15. One end portion and the other end portion of the partition member 24 are inserted into the recess through the cap member 24c.

  As shown in FIGS. 8 and 9, the partition member 22 is configured by providing a resin layer 22b on the entire surface of a metal plate 22a that is a heat-resistant core material. Similarly, the partition member 24 is also configured by providing a resin layer 24b on the entire surface of the metal plate 24a that is a heat-resistant core material.

  With reference to FIG.8 and FIG.9, the method to manufacture a hollow molded object using the rotational molding apparatus shown in FIG. 6 is demonstrated. First, a predetermined amount of resin powder 21 made of a thermoplastic resin such as polyethylene is put into the lower mold 12. Next, the partition member 22 having the cap member 22c attached to the periphery thereof is disposed on the flange portion 12a above the lower mold 12. Next, the half molds 13 and 14 are placed on the lower mold 12. Thereby, the cap member 22c around the partition member 22 is inserted into the recess 13b and the recess 14b. Next, a predetermined amount of resin powder 23 made of a thermoplastic resin such as polyethylene is placed on the partition member 22.

  Next, as shown in FIG. 9, on the flange portions 13c and 14c of the half molds 13 and 14, partition members 24 having cap members 24c attached to both ends are arranged. On top of that, the upper mold 15 is placed.

  The lower mold 12, the half molds 13 and 14, and the upper mold 15 are each fixed by a metal fitting or the like to form one mold.

  In this state, the mold is heated while rotating the mold in the biaxial direction by the first rotation driving means and the second rotation driving means shown in FIG. 6, and the resin powders 21 and 23 in the mold are heated. Melt. As a result, the molten resin powder adheres to the inner surface of the mold, and a wall portion having a constant film thickness is formed in the mold.

  Along with such melting of the resin powder, the resin layer 22b on the surface of the partition member 22 arranged in the mold, the resin layer 24b on the surface of the partition member 24, the cap member 22c and the cap member 24c are also melted, and the molten resin And is formed integrally with the wall portion. By cooling the mold while rotating the mold in this state, the resin in the mold is solidified to form a hollow molded body.

  As described above, the resin forming the wall portion in the mold, the resin layer on the surface of the partitioning member, and the cap member are melted and integrated during the rotation molding, whereby the book shown in FIGS. The hollow molded object 1 of an Example can be obtained.

  In the hollow molded body of this example, as described above, the resin layer is provided on the entire surface of the partition plate, and the entire interior of the hollow molded body is covered with resin, so that it is excellent in chemical resistance and the like. A hollow molded body can be obtained. Therefore, it can be used as a hollow container or the like that can store various liquids.

  In addition, since the resin portion on the surface of the partition plate is integrally formed with the wall portion, the partition plate is firmly attached to the wall portion, and effectively prevents leakage or the like of the liquid partition plate contained therein. be able to.

  As a comparison, a partition plate made only of a metal plate whose surface is not covered with a resin layer is used, and a cap member is attached to the end of the partition plate in the same manner as in the above embodiment, and a hollow is formed in the same manner as in the above embodiment. A molded body was produced. As a result, in the hollow molded body of this comparative example, the close contact with the wall portion at the end portion of the metal plate is insufficient, and by applying a slight force, a gap is formed between the metal plate that is the partition plate and the wall portion. occured. Further, when liquid was stored in the internal space A1 and the internal space A1 was positioned upward, liquid leakage was observed from the partition plate.

  On the other hand, in the hollow molded body of the present embodiment in which the entire surface of the partition plate is covered with the resin layer according to the present invention, even when the liquid is put in the internal space A1 and the internal space A1 is positioned above, Liquid leakage from the internal space A1 was not recognized.

  In the above embodiment, a partition member in which a resin part is formed on a metal plate is shown as the partition member. However, in the present invention, it is sufficient that at least the entire surface is formed of a resin part. The whole partition member may be formed from resin. Therefore, as shown in FIG. 11, a partition member 22 formed entirely of resin may be used.

  In the above embodiment, the partition member to which the cap member is attached is disposed in the concave portion of the mold. However, in the present invention, as shown in FIG. 12, the partition member 22 is directly connected without using the cap member. You may insert and arrange | position to the recessed part 13b of a metal mold | die. In this case, the recess 13b of the mold is formed so as to follow the shape of the end of the partition member 22.

  FIG. 13 is a perspective view showing a hollow molded body of another embodiment according to the present invention. The hollow molded body shown in FIG. 12 is the hollow molded body shown in FIG. 1 to FIG. As described above, the hollow molded body produced according to the present invention can be subjected to various processing after molding and used for various applications.

The perspective view which shows the hollow molded object of one Example according to this invention. FIG. 2 is a cross-sectional view in the lateral direction of the hollow molded body shown in FIG. 1. Sectional drawing of the vertical direction of the hollow molded object shown in FIG. Sectional drawing which follows the XX 'line shown in FIG. Sectional drawing which expands and shows the Y vicinity shown in FIG. The front view which shows the rotational molding apparatus which manufactures the hollow molded object of one Example according to this invention. The side view which shows the metal mold | die of the rotational molding apparatus shown in FIG. Sectional drawing which follows the paper surface direction of FIG. 6 which shows the state in the metal mold | die at the time of manufacturing a hollow molded object using the rotational molding apparatus shown in FIG. Sectional drawing in alignment with the paper surface direction of FIG. 6, and the state in a metal mold | die at the time of manufacturing a hollow molded object using the rotational molding apparatus shown in FIG. Sectional drawing which expands and shows the Z vicinity shown in FIG. The expanded sectional view which shows the partition member in the other Example according to this invention. The expanded sectional view which shows the other example which arrange | positions the partition member in this invention in the recessed part of a metal mold | die. The perspective view which shows the hollow molded object of the further another Example according to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hollow molded object 2 ... Wall part 2a ... Corner part 2b ... Periphery convex part 2c ... Convex part 2d, 2e ... Hole 3 ... Partition plate 3a ... Metal plate 3b ... Resin layer 4 ... Partition plate 4a ... Metal plate 4b ... Resin Layer 11 ... Rotary molding device 12 ... Lower mold 13,14 ... Half mold 13b, 13d, 14b ... Mold recess 15 ... Upper mold 12a, 13a, 13c, 14a, 14c, 15a ... Flange part 16, 17 ... Air valve 16a, 17a ... Air valve hole 21, 23 ... Resin powder 22 ... Partition member 22a ... Metal plate 22b ... Resin layer 22c ... Cap member 24 ... Partition member 24a ... Metal plate 24b ... Resin layer 24c ... Cap member 32, 33 ... opening

Claims (14)

A method for producing a hollow molded body provided with a partition plate for partitioning an internal space by a rotational molding method,
At least a partition member having a resin layer provided on the entire surface is placed in the mold and fixed in position, and then the mold is heated to melt the powdered thermoplastic resin charged in the mold. And rotating the mold to adhere the molten resin to the inner wall surface of the mold to form a wall portion of the hollow molded body, and to integrate the resin layer on the surface of the partition member and the molten resin. A hollow molded body by a rotational molding method, wherein a partition plate made of the partition member and a wall portion of the hollow molded body are integrally formed to form a hollow molded body provided with a partition plate therein Manufacturing method. A method for producing a hollow molded body provided with a partition plate for partitioning an internal space by a rotational molding method,
Preparing a partition member provided with a resin layer on at least the entire surface;
Installing the partition member in a mold and fixing its position;
Before or after the partition member is installed in the mold, a process of introducing a powdered thermoplastic resin into the mold; and
The mold is heated, the powdery thermoplastic resin in the mold is heated and melted, the mold is rotated, and the molten resin is attached to the inner wall surface of the mold to form a hollow molded body. Forming the wall part, integrating the resin layer on the surface of the partition member and the molten resin, and integrally forming the partition plate made of the partition member and the wall part of the hollow molded body; ,
And a step of removing the mold after cooling the mold and taking out the hollow molded body in which the partition plate is integrally formed. Method.   The said resin layer is formed from the thermoplastic resin, The manufacturing method of the hollow molded object by the rotational molding method of Claim 1 or 2 characterized by the above-mentioned.   The method for producing a hollow molded body by the rotational molding method according to any one of claims 1 to 3, wherein the entire partition member is formed of a resin.   The said partition member is a partition member which coat | covered the whole surface of the heat resistant core material with the said resin layer, The hollow molded object by the rotational molding method of any one of Claims 1-3 characterized by the above-mentioned. Production method.   After the partition member adheres the powder resin onto the core material by a powder coating method, the powder resin is melted by heating to form the resin layer on the surface of the core material The method for producing a hollow molded body by a rotational molding method according to claim 5, wherein   6. The rotational molding according to claim 5, wherein the partition member is formed by immersing the heated core material in a powder resin to form the resin layer on the surface of the core material. A method for producing a hollow molded body by the method.   The said core material is a metal plate, The manufacturing method of the hollow molded object by the rotational molding method of any one of Claims 5-7 characterized by the above-mentioned.   The said partition plate is provided so that the space of the both sides may be partitioned completely, The manufacturing method of the hollow molded object by the rotational molding method of any one of Claims 1-8 characterized by the above-mentioned.   The said partition plate is provided so that a part of space of the both sides may be partitioned, The manufacturing method of the hollow molded object by the rotational molding method of any one of Claims 1-8 characterized by the above-mentioned.   A recess for holding the end of the partition member is formed on the inner wall surface of the mold, and the end of the partition member is disposed in the recess so that the partition member is placed in the mold. The method for producing a hollow molded body by a rotational molding method according to any one of claims 1 to 10, wherein the position is fixed to the position.   The position of the partition member in the mold during rotation molding is fixed by being held in the recess of the mold so that the end of the core material is positioned. The manufacturing method of the hollow molded object by the rotational molding method of Claim 11.   12. A cap member made of a thermoplastic resin is attached to an end portion of the partition member, and the end portion of the partition member is held in the concave portion of the mold through the cap member. Or the manufacturing method of the hollow molded object by the rotational molding method of 12.   The mold is formed by combining a plurality of partial molds, and a flange portion is formed at a butt end portion of the partial mold, and the concave portion of the mold is formed from the flange portions of the partial molds to be butted together. The method for producing a hollow molded body by a rotational molding method according to any one of claims 11 to 13, wherein

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