JP2001246631A - Molding apparatus and molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a compression ratio in a molding process to enhance the productivity of open-cell foam. SOLUTION: A molding apparatus is constituted of an injection part 1 of a foamable raw material, a retaining mold 2, a partition plate 4 and a lid 5 all of which moves through a molding passage together and a device for pushing the lid 5 in the retaining mold 2. The compression ratio of the foamable raw material 1a is changed in the molding process using this molding apparatus to manufacture a molded object comprising open-cell foam with a communication degree of 99% or more in such a state that a skin layer is left.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus and a molding method for continuously producing a molded article of an open-cell foam.

[0002]

2. Description of the Related Art Recently, for the purpose of protecting the ozone layer and preventing global warming for the preservation of the global environment, many manufacturing fields have been pursuing elimination of CFCs and energy saving, and materials conversion has been demanded. In particular, heat insulating materials such as rigid polyurethane foams have become targets.

[0003] For this reason, various techniques have been proposed in the field of the production of heat insulating materials. For example, a production method using water as a foaming agent is known as a technique for removing CFCs. Further, for the purpose of energy saving, a bag made of a gas-barrier metal-plastic laminated film is filled with a core material such as an inorganic powder or an open cell to maintain a predetermined shape, and a vacuum heat insulating panel sealed under reduced pressure. A structure has been proposed.

Under these circumstances, rigid polyurethane foams composed of open cells are considered to be lightweight and have high performance, and are used as heat insulating materials for refrigeration / refrigeration equipment for preventing global warming. It is attracting attention as a core material.

[0005] For example, Japanese Patent Publication No. 63-61589,
Japanese Patent Application Laid-Open No. Hei 6-213561 discloses a high-performance vacuum heat insulating material using a rigid polyurethane foam having open cells made of water foam as a core material, and making the cells of the foam finer and adjusting the shape of the cells. It has been proposed to obtain

[0006] The present applicant has filed a patent application No. 1999/1999.
No. 70732 proposes a method for forming an open-cell foam by multi-stage compression molding. In this molding method,
First, as shown in FIGS. 5 (1) and 5 (2), a foaming material d is injected into a space formed by an upper mold b and a lower mold c, and the foaming material is freely foamed in this state. Prior to the gel time of the free-foamed product e, the upper die b is pressed by the press a as shown in FIG.
Is gradually pushed in to compress the free foamed material e (first compression). After a lapse of a predetermined time at this stage, the upper die b is further pushed in by the press a as shown in FIG. Thing f
Is compressed (second compression) to obtain a final molded body g. By performing such two-stage compression molding, it is possible to produce a molded article of an open-cell foam having a communication degree of 99% or more while leaving a surface layer portion called a skin layer.

[0007]

However, the above-mentioned method for producing a rigid polyurethane foam having open cells usually involves injecting a foaming raw material into a lower mold and then closing the foamed raw material with an upper mold.
It is manufactured by constraining and compressing the foaming raw material in the foaming process. In this method, the productivity is not high because the mold is cleaned or the stock solution is injected every time one rigid polyurethane foam having the foamed cells is manufactured.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the conventional molding apparatus and molding method as described above.
An object of the present invention is to improve the productivity of an open-cell foam by changing the compression ratio in a molding process.

[0009]

In order to achieve the above object, a molding apparatus according to the first aspect of the present invention continuously manufactures an open-cell foam while moving along a molding path. In the molding apparatus, the molding path is moved, and a molding die composed of side walls and a bottom surface, an injection section for injecting the raw material of the foam into the molding die, and the molding die are moved together with the molding die. , And a device for pushing the lid into the forming mold.

According to a second aspect of the present invention, there is provided a molding apparatus for continuously producing a molded article of an open-cell foam while moving along a molding path. A molding mold, an injection section for injecting the raw material of the foam into the molding mold, a partition plate that moves together with the molding mold, and partitions the molding mold in the transverse direction. A lid arranged in a partitioned molding form,
And a device for pushing the lid into the forming mold.

According to a third aspect of the present invention, there is provided a molding apparatus according to the first or second aspect, wherein the pushing device is capable of compressing the lid into the molding form in multiple stages.

According to a fourth aspect of the present invention, there is provided a molding method for continuously producing a molded article of an open-cell foam while moving the molding path. A molding method characterized by injecting a raw material of a foam into a molding frame composed of: and compressing the foam in the molding frame with a lid to continuously produce a molded article of an open-cell foam. It is.

According to a fifth aspect of the present invention, there is provided a molding method for continuously producing a molded article of an open-cell foam while moving the molding path, wherein the molding path is moved and is constituted by a side wall and a bottom surface. The raw material of the foam is poured into the molding form, the foam in the molding form is transversely partitioned by a partition plate, and the foam separated by the molding form and the partition plate is compressed by a lid to obtain an open-cell foam. A molding method characterized by continuously producing a molded article of the above.

According to a sixth aspect of the present invention, there is provided the molding method according to the fourth or fifth aspect, wherein the foam in the molding mold is compressed in a multi-step manner by a lid. .

According to a seventh aspect of the present invention, there is provided the molding method according to the sixth aspect, wherein the first-stage compression of the foam is performed by restraint.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a molding apparatus and a molding method according to the present invention will be described with reference to the drawings. In the embodiment of the molding apparatus described first, the shape of the molding passage is a rectangular cylindrical shape, and only an example using a partition plate is described and illustrated, but the present invention is not limited thereto, For example, the shape may be a polygon having more than a triangle and a curved surface, and a partition plate may not be used.

<A> Configuration of Entire Forming Apparatus FIG. 1 is a side view (A) conceptually showing a forming apparatus according to an embodiment of the present invention, and an enlarged sectional view (B) of the same essential parts. The apparatus of the illustrated embodiment inputs a foaming material into the molding form 2 from the injection section 1 and forms the molding passage 13 while moving the molding form 2 together with the lid 5 and the partition plate 4 that can move up and down. ,
By pressing the lid 5 into the molding passage in multiple stages or continuously, the molded body of the foam is continuously molded. The moving configuration of this apparatus includes a lower conveyor 3 and an upper conveyor 7 on each of which a plurality of forming molds 2 and brackets 6 are attached without any gap. These brackets 6
As shown in FIG. 2, the lid 5 and the partition plate 4 are attached so that they can slide up and down. By winding the upper conveyor 7, the lid 5 and the partition plate 4 are moved along the fixed vertical cams 8 and 9, respectively, along with the vertical cam followers 10,
11 to move up and down. Therefore, the vertical cams 8 and 9
The shape of the vertical movement of the lid 5 and the partition plate 4 can be easily set according to the molding process. Next, each part of the present apparatus will be specifically described.

<B> Injection Unit 1 The injection unit 1 is composed of a material injection head. Into the injection head, for example, a foaming raw material 1a produced by mixing with a high-pressure foaming machine is supplied. A predetermined amount of the foaming material is injected from the injection head into the moving mold 2. The injection amount is determined in advance based on the thickness of the foam molded body.

<C> Forming Formwork 2 As shown in FIGS. 1B and 2, the forming formwork 2 is connected between a bottom surface 21 and a pair of side walls 22 by a hinge 23 so as to form a groove. The side walls 22, 22 can be turned sideways by hinges 23. The molding form 2 and the lid 5 form a molding passage having a desired shape and dimensions.

The molding die 2 has driving conveyor chains 31, 31 attached to both sides of the outer surface of the bottom surface 21. The conveyor chain 31 is wound around a pair of chain wheels 32, 32, and circulates and rotates by driving one of the chain wheels 32 by driving means (not shown). It is designed to circulate and rotate with 31.

<D> Lid 5 The lid 5 is mounted on the bracket 6 so as to be slidable up and down as shown in FIGS. The bracket 6 is attached to the driving conveyor chains 71, 71. The conveyor chain 71 is wrapped around a pair of chain wheels 72, 72, and circulates and rotates by driving one of the chain wheels 72 by a driving means (not shown).
Both are configured to circulate and rotate together with the conveyor chain 71.

The lid 5 is moved up and down by a lid vertical cam follower 11 which moves along the lid vertical cam 9 by the movement of the conveyor chain 71 as shown in FIG. Accordingly, the lid 5 is lowered into the molding frame 2 or into a space formed by the partition plate 4, and pushes the foam to perform compression molding. The timing and the number of compressions can be appropriately designed depending on the shape of the cam 9.

On the other hand, as shown in FIGS. 1 (B) and 3 (B), in order to prevent leakage of the foaming material having fluidity from the molding passage 13, the endless trough belt 12 is
What is necessary is just to mount it on the entire inner wall surface of the molding form 2 and rotate it with a lower conveyor (not shown). When the partition plate 4 is not used, the same trough belt 12 is attached to the bottom surface 52 and the side surface 53 of the lid 5. As shown in FIG. 3, the trough belt 12 includes a first layer material 121 that comes into contact with a molding material or a molded body.
It is composed of a second layer material 122 that comes into contact with the inner wall surface of the forming mold frame 2, and two cuts 123 are formed between the second layer materials 122 in order to bend easily.

As the first layer material 121, a material having a required sealing property with respect to the foaming raw material and a required releasing property with respect to the foamed material during molding and the molded product after curing is used. Examples of such a material include a cloth made of polyaramid fiber or glass fiber or a composite cloth thereof impregnated with a fluorine-based resin so as to have releasability and heat resistance. On the other hand, the second layer material 122
May be used, but a material having a low friction with the molding die 2 or the lid 5 and having durability and tensile strength can be appropriately used.

<E> Partition plate 4 Like the lid 5, the partition plate 4 is mounted on the bracket 6 so as to be movable in the vertical direction, and circulates and rotates together with the conveyor chain 71. The partition plate 4 is moved up and down by a partition plate vertical cam follower 10 that moves along the partition plate vertical cam 8 by the movement of the upper conveyor in the same manner as the lid 5. Normally, before performing the compression step, the partition plate 4 is lowered to partition the inside of the molding die 2 in the transverse direction, and the partition plate 4 is raised with the progress of the compression step.

<F> Push-in device The push-in device mainly comprises the up-and-down moving cams 8 and 9 and the pressing members 41 and 51 as shown in FIGS. This vertical cam 8,
Reference numerals 9 are respectively fixed to support frames (not shown). On the other hand, one end of each of the pressing members 41 and 51 is provided with the partition plate 4.
And the lid 5, and the other end is provided with a cam follower 10,
11 are connected. The pressing members 41 and 51 are guided by the bracket 6 and are movable vertically. Therefore, as the upper conveyor 7 rotates, the partition plate 4 and the lid 5 can be moved up and down at a place where a molding passage is required.

On the other hand, the vertical movement of the partition plate 4 and the lid 5, especially the lid 5
Does not necessarily need to be pushed by the pushing device. For example, the movement of the lid 5 may be automatically controlled by a driving motor or an air cylinder attached to each bracket 6.

Next, the molding method of the present invention will be described. <A> Outline of molding method. In the molding method of the present invention, each component of the foaming raw material is produced by a usual method, for example, by mixing with a high-pressure foaming machine to produce a foaming raw material, and compression molding is performed on the obtained foaming raw material using the above molding apparatus. Do. The compression molding can be performed in multiple stages or continuously. In this way, in the case of an open-celled rigid polyurethane foam molded article, as described in Japanese Patent Application No. 11-170732, an open-cell foamed article obtained by performing multi-stage or continuous compression molding in this manner, The air bubbles have a crushed shape over the entire inner part of the molded body to the skin layer, and the communication between the surface layer part and the center part is 99% with the skin layer remaining.
% Or more. Hereinafter, only an example of a molding method using a molding device provided with the partition plate 4 will be specifically described, but the molding method of the present invention is not limited to this, and may vary depending on the fluidity of the foaming raw material. Also, the present invention is applied to a case where the partition plate 4 is not required.

Here, the “skin layer” of the foam molded article used in the present specification refers to a surface layer portion (surface layer) in the foam molded article. In conventional rigid polyurethane foam moldings,
Since a skin layer having sufficient open cells could not be obtained, it is necessary to remove the reskin layer from the obtained foamed molded article after foam molding in order to obtain an open-celled rigid polyurethane foam molded article. Atsuta.

As used herein, the term “communication degree” refers to the open cell rate. Specifically, when the closed cell rate measured based on ASTM-D1940 is Cr, it is 100%.
−Cr can be calculated.

Further, as a method of the multi-stage or continuous compression molding, more specifically, a molding method including the following steps (1) to (4) is exemplified. (1) A step of injecting the foaming raw material into the moving mold 2 during the movement, and freely foaming the mold 2 until it is completely partitioned by the partition plate 4. (2) A free foaming process of the step (1). A first compression step of compressing the free-foamed product with the lid 5 before the gel time (hereinafter, also referred to as “first-stage compression”), (3) the compressed product obtained in the above (2) step Is further compressed by the lid 5 before the rise time (hereinafter, also referred to as “second-stage compression”). (4) After the step (3), the partition plate 4 is pulled out and removed. The process of molding.

The terms “cream time”, “gel time”, and “rise time” used in the present specification are defined as follows. That is, after mixing the foaming raw materials in the foam molding, the time when the mixture starts foaming, the `` cream time '', the time to start pulling the thread when the glass rod or the like is pierced and pulled into the foam during foaming, The “gel time” and the time when foaming ends, that is, the time when foam expansion stops, is called “rise time”.

The molding method including the above steps (1) to (4) will be described more specifically with reference to the conceptual process diagram shown in FIG.

<A> Injection of Raw Material First, a molding die 2 (not shown) is transported to a predetermined position by a lower conveyor 3, and a raw material 1 a of a foam is injected from the injection portion 1 into the molding die 2.
Is injected in a predetermined amount. The injection amount is determined in advance based on the cream time, the rotation speed of the lower conveyor 3, the size of the molded body, and the like.

<B> Partitioning by Partitioning Plate 4 Immediately after the injection of the raw material 1a, the partitioning plate 4 is lowered at a predetermined speed while moving in synchronization with the movement of the molding frame 2. This predetermined speed may be adjusted in advance based on the shape of the cam 8 for vertically moving the partition plate (not shown) (inclination gradient at one end of the cam).

<C> Compression by Lid 5 By the time the lowering of the partition plate 4 is completed, the lid 5 is moved at a predetermined altitude in synchronization with the movement of the molding form 2. In this way, the forming mold 2, the partition plate 4 and the lid 5 form a small box. At this time, the foam material 1a is filled in the box.

Immediately before the gel time, the lid 5 is pushed into a predetermined position in the box by the lid vertical movement cam 9 to perform the first-stage compression. The first-stage compression may continue intermittently or continuously lowering before the start of the second-stage compression as shown in FIG. Alternatively, it may be performed by restricting the lid 5 at a predetermined height. After a certain period of time has elapsed at this stage, that is, immediately before the rise time, and preferably immediately after outgassing, the lid 5 is further pushed by the cam 9 to perform the second-stage compression.

The compression ratio of the first stage is preferably 40 to 80% with respect to the volume when free foaming is performed without compression.
Degree. The volume in the case of free foaming without compression described here is, for example, when the foaming raw material component mixture is freely foamed in a container with an open top, the top surface is left open, that is, the upper surface is not restrained Means the volume of the foam obtained by freely foaming the foaming raw material component mixture until the rise time and then curing.

The compression ratio in the second stage is preferably 10 to 30 with respect to the volume when free foaming is performed without compression.
%.

It should be noted that the partition plate 4 is formed such that the molding form 2 is
In the continuous molding apparatus of the present invention, which is constituted by the bottom and the bottom 22 and is opened in the moving direction, when the foam has fluidity during compression, the strength of the foam is weak by compression. This is provided because a phenomenon of being pushed out to the side may occur. If there is little fluidity during compression due to adjustment of the composition of the foaming raw material or the like, compression can be performed without providing the partition plate 4.

<D> Demolding After the compression is completed, the cam 8 pulls out the partition plate at a predetermined speed. Thereafter, the lid 5 is removed by the cam 9 and the mold 2 is removed.
Side walls are opened to the side, and the molded product is sequentially and smoothly removed from the mold.

The final state of the molded body is as follows depending on the timing at which the partition plate 4 is pulled out. (A) When the partition plate 4 is pulled out in a state where the foam is not sufficiently cured, a cut is formed on the surface of the molded body. However, these cuts can be completely adhered, and finally a continuous molded article can be formed. (B) After the foam is completely cured, the partition plate 4 is pulled out to obtain a compact which is cut into small spaces between the partition plates 4.

[0043]

Since the molding apparatus and the molding method of the present invention have been described above, the following effects can be obtained. <A> The present invention can efficiently produce a good open-cell foam molded article by changing the compression ratio in the molding process.

[Brief description of the drawings]

FIG. 1 is a molding apparatus of the present invention.

FIG. 2 is a perspective view of a moving device.

FIG. 3 is a structural diagram of a trough belt.

FIG. 4 is a conceptual diagram of a molding process.

FIG. 5: Conventional molding method

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection part 1a Foaming raw material 2 Mold form 21 Bottom of mold form 22 Side wall of mold form 23 Hinge 3 Lower conveyor 31 Lower conveyor chain 32 Lower chain wheel 4 Partition plate 41 Pressing material (for partition plate 4) 5 Cover 51 Pressing material (for lid 5) 6 Bracket 7 Upper conveyor 71 Upper conveyor chain 72 Upper chain wheel 8 Vertical cam (for partition 4) 9 Vertical cam (for lid 5) 10 Vertical cam follower (for partition 4) DESCRIPTION OF SYMBOLS 11 Vertical cam follower (for lid 5) 12 Trough belt 121 Trough belt first layer material 122 Trough belt second layer material 123 Cut 13 Forming passage

Claims (7)

[Claims] 1. A molding apparatus for continuously producing a molded article of an open-cell foam while moving along a molding path, comprising: a molding mold moving along a molding path and comprising a side wall and a bottom surface; An injection unit for injecting the raw material of the foam into the molding die, a lid that moves together with the molding die, and is disposed in the molding die, and a device that pushes the lid into the molding die. Molding equipment for continuously producing molded articles of open-cell foam. 2. A molding apparatus for continuously producing a molded article of an open-cell foam while moving along a molding passage, comprising: a molding mold formed by moving a molding passage and comprising a side wall and a bottom surface; An injection section for injecting the raw material of the foam into the mold, a partition plate that moves together with the molding frame and partitions the molding frame in the transverse direction, and moves together with the molding frame and is placed in the molding frame partitioned by the partition plate A molding apparatus for continuously producing a molded article of an open-cell foam, comprising: a lid to be pressed; and a device for pushing the lid into a molding die. 3. The molding device according to claim 1, wherein the pushing device is capable of compressing the lid into the molding mold in multiple stages. 4. A molding method for continuously producing a molded article of an open-cell foam while moving a molding passage, wherein the molding passage is moved and a raw material of the foam is placed in a molding mold having a side wall and a bottom surface. And molding the foam in the molding mold with a lid to continuously produce a molded article of an open-cell foam. 5. A molding method for continuously producing a molded article of an open-cell foam while moving a molding passage, wherein the molding passage is moved and a raw material of the foam is placed in a molding mold having a side wall and a bottom surface. The foam in the forming mold is partitioned by a partition plate in the transverse direction, the foam separated by the forming mold and the partition plate is compressed by a lid, and the open-cell foam is continuously produced. Molding method. 6. The molding method according to claim 4, wherein the foam in the molding form is compressed in a multi-stage manner by a lid. 7. The molding method according to claim 6, wherein the first-stage compression of the foam is performed by restraint.