CN101830048B - EVA foaming material forming method and device - Google Patents

Abstract

The invention relates to a method for forming EVA foaming material and its device, which arranges the mould for molding EVA foaming material and the product blank and the cooling shaping mould in a pressure-controlled main chamber with controllable pressure, and separates two independent first and second pressure-controlled sub-chambers in the main chamber to hold each mould in it, to control the pressure value of the environment of each mould by each sub-chamber, to achieve the specific effects of flexible use, energy saving and shortening working hours.

Description

Forming method and device of EVA foam

technical field

The invention relates to a polymer processing technology, in particular to a molding method of EVA foam and its device.

Background technique

In order to improve the many deficiencies derived from the traditional two-stage process of EVA foam molding, a one-stage process is disclosed in the Chinese Patent No. 03137138.8 and No. 03263374.2, which mainly uses the traditional two-stage process respectively. The embryo mold and the shaping mold are placed in the same pressure chamber. By controlling the internal pressure of the pressure chamber, the EVA foam can pass through the high-pressure environment of the pressure chamber during the process of transferring from the embryo mold to the shaping mold. To prevent its volume from expanding beyond the size of the cavity of the shaping mold to be filled, after the EVA foam is properly filled into the cavity of the shaping mold, the pressure chamber is decompressed to a normal environment of atmospheric pressure, so that the The EVA foam is cooled and molded in the shaping mold to become a finished product.

The above-mentioned prior patent is inherently practical, but, as far as the requirements of the EVA foam manufacturing process are concerned, the method of controlling through a single pressure chamber is not ideal. Specifically, when molding the EVA embryo with the embryo mold, due to It is necessary to completely remove the gas in the mold chamber for containing the EVA raw material, so as not to affect the molding of the EVA embryo. In this previous stage, the injection and foaming process must be carried out in a vacuum environment; moreover, The EVA foam made by the injection foaming process of the previous stage needs to be cooled and shaped in the latter stage, and the cooling and shaping procedure is carried out through a shaping mold with a cooling effect, that is, in the latter stage , the EVA foam that is still in a high temperature state is filled into the finished mold chamber in the shaping mold, and then cooled and molded into the corresponding shape and surface texture. At this time, if there is still gas in the finished mold chamber, then It will also occupy the space of the mold chamber, making the shaping of the EVA foam incomplete and affecting the quality of the finished product.

Of course, in the implementation of this patent, the pressure control of the pressure chamber can also be used to meet the needs of the upper opening process, but unfortunately, even if it is done in this way, because the overall space of the pressure chamber is too large, The procedure of repeatedly pressurizing and vacuumizing will generate excessive waste of energy and time, which is not an ideal method.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a molding method of EVA foam and its device, which can reduce the use of energy and shorten the time required for pressure changes when manufacturing EVA foam with a one-stage process. To improve the efficiency of the process.

Therefore, in order to achieve the above object, the present invention provides a molding method of EVA foam, comprising the following steps

a. Place the first and second molds together in a sealed pressure-controlled main chamber space;

b. forming a closed first pressure-controlled secondary chamber in the space of the pressure-controlled main chamber that completely accommodates the first mold and exists independently in the pressure-controlled main chamber;

c. Clamp the first mold after removing the gas in the first pressure-controlled sub-chamber, and make the EVA raw material react in the internal closed mold chamber of the first mold after the mold clamping to form an embryo;

d. Opening the first voltage-controlled secondary chamber so that the space of the first voltage-controlled secondary chamber becomes a part of the space of the voltage-controlled main chamber;

e. Increase and maintain the gas pressure in the pressure-controlled main chamber;

f. Open the first mold so that the embryo is pressed by the gas pressure of the pressure-controlled main chamber without fully foaming and expanding;

g. moving the embryo and filling it into the cavity of the second mold in the mold opening state;

h. Forming a closed second pressure-controlled sub-chamber in the space of the pressure-controlled main chamber that completely accommodates the second mold and exists independently in the pressure-controlled main chamber;

i. Clamping the second mold after exhausting the gas in the second pressure-controlled secondary chamber;

j. Using the second mold, the blank is cooled in the inner mold chamber of the second mold and molded to form a finished product.

The implementation of the molding method of the EVA foam can be carried out through a specific molding device of the EVA foam; specifically, the molding device of the EVA foam includes a body with a sealable pressure control main body chamber space; a first and a second mold group, which are separately arranged on the body and located in the pressure-controlled main room space; a first inner shell, which is arranged around the first mold group, and can be closed in a and an open position, when located at the closed position, a closed first pressure-controlled secondary chamber space that completely accommodates the first mold and exists independently in the pressure-controlled main chamber space is formed, and when located at the open When the position is on, the space enclosed by the first pressure-controlled secondary chamber is opened to make it a part of the space of the pressure-controlled main chamber; a second inner shell is arranged around the second mold group, and can be placed on a Move between a closed position and an open position. When located at the closed position, a closed second pressure-controlled secondary chamber space that completely accommodates the second mold and exists independently in the pressure-controlled main chamber space is formed. When located at the When the opening position is on, the space enclosed by the second voltage-controlled secondary chamber is opened to make it a part of the space of the voltage-controlled main chamber.

Hereinafter, a preferred embodiment of the present invention will be cited and further described in conjunction with the drawings, wherein:

Description of drawings

Fig. 1 is a three-dimensional appearance view of a molding device for EVA foam in a preferred embodiment of the present invention.

Fig. 2 is an appearance view of the molding device of EVA foam in a preferred embodiment of the present invention after removing the shell body and the closing plate member.

Fig. 3 is a schematic flow diagram (1) of a molding method of EVA foam implemented by a molding device of EVA foam according to a preferred embodiment of the present invention, showing step a to step c.

Fig. 4 is a schematic flow diagram (2) of a molding method of EVA foam implemented by a molding device of EVA foam according to a preferred embodiment of the present invention, showing step d to step j.

Detailed ways

First of all, please refer to Fig. 1 and Fig. 2, the forming device 10 of EVA foam provided in a preferred embodiment of the present invention consists of a body 20, two pressing parts 30, a first mold set 40, a The second mold group 50 is composed of a first inner shell 60 and a second inner shell 70, wherein:

The body 20 has a base 21, a plate-shaped top 22 is horizontally located at an appropriate height above the base 21, and an annular shell portion 23 with compression resistance is bridged between the top 22 and the base 21. The main control room 24 is an inner space surrounded by the base, the top and the shell parts 21, 22, 23; further, the shell part 23 includes an annular shell body 231, which is bridged between the top 22 and the shell part 23. Between the base 21, two square openings 232 are respectively set on the front side wall of the shell body 231, so that the pressure control main chamber 24 can communicate with the outside world through it, and two closing plates 233 are respectively slid on the shell body 231 on the front side shell surface, and can slide between a closed position and an open position respectively. When located in the closed position, each of the closed plates 233 respectively closes a corresponding opening 232 so that the pressure control main chamber 24 Lost the channel communicating with the outside, resulting in an airtight state, and when located in the open position, each of the closing plates 233 makes each of the openings 232 open again, so as to restore the communication between the voltage control main chamber 24 and the outside.

Each of the pressing parts 30 has a pair of rotating rods 31, which are upright and parallel to each other on both sides of a corresponding opening 232. A plurality of clamping blocks 32 are symmetrically fixed on the body of the rotating rod 31, and can be rotated with each other. The rotation of the rotating rod 31 changes the position in the horizontal direction. A driving connecting rod 33 is positioned and pivoted above the top 22. A pressure cylinder 34 drives the driving connecting rod 33 through the output shaft to drive the counter rotating rod. 31, so that each of the clamping blocks 32 can be locked on the corresponding closing plate 233 at the closed position, so as to maintain the airtightness between each of the closing plates 233 and the shell body 231.

Each of the first and second mold sets 40, 50 is arranged side by side on the machine body 20, and is located in the space of the pressure control main chamber 24, and respectively corresponds to a position where an opening 232 is located, wherein the first Mold set 40 is a traditional injection foaming mold for molding EVA embryos, and the second mold set 50 is a traditional cooling shaping mold for molding EVA finished products, and its relevant technical contents have been disclosed The traditional technology, thus no longer redundant.

The first inner shell 60 can be ring-shaped, and the ring is arranged on the peripheral side of the first mold group 40, and can move between a closed position and an open position. close contact with the top 22 to form a closed first pressure-controlled secondary chamber space 61 that completely accommodates the first mold 40 and exists independently in the space of the pressure-controlled main chamber 24, and when located in the open position When going up, the space enclosed by the first voltage-controlled secondary chamber 61 is opened to become a part of the space of the voltage-controlled main chamber 24 .

The second inner shell 70 can be ring-shaped, and is arranged on the peripheral side of the second mold group 50, and can move between a closed position and an open position. closely abuts on the top 22 to form a closed second pressure-controlled secondary chamber space 71 that completely accommodates the second mold 50 and exists independently in the space of the pressure-controlled main chamber 24, and when located in the open position When going up, the space enclosed by the second voltage-controlled secondary chamber 71 is opened to become a part of the space of the voltage-controlled main chamber 24 .

Please refer to Fig. 3 and Fig. 4 again, the molding method of the EVA foam provided in a preferred embodiment of the present invention can be implemented by the molding device 10 of the EVA foam, specifically, Its steps include:

a. Place the first and second mold groups 40, 50 in the space of the pressure control main chamber 24, and make each of the closing plates 233 close the corresponding openings 232, so that the space of the pressure control main chamber 24 Closed to the outside world.

b. Move the first inner shell 60 up to the closed position, and use the first pressure-controlled sub-chamber 61 to accommodate the first mold set 40 .

c. After the gas in the first pressure-controlled sub-chamber 61 is pumped away, the first mold group 40 is closed to form a vacuum inside the inner blank mold chamber 41; The cylinder injects the EVA raw material into the blank mold chamber 41, and raises the temperature so that the EVA raw material reacts in the mold chamber 41 to be molded to form a blank.

d. Move the first inner shell 60 down to the opening position to open the first voltage-controlled secondary chamber 61 , so that the space of the first voltage-controlled secondary chamber 61 becomes a part of the space of the voltage-controlled main chamber 24 .

e. Increase the gas pressure in the pressure-controlled main chamber 24 and maintain it at least until the completion of the following step g.

f. Opening the first mold group 40, so that the embryo is pressed by the gas pressure of the pressure-controlled main chamber 24 without fully foaming and expanding.

g. Move the embryo and fill it into the mold cavity 511 of the second mold set 50 in the mold-opening state.

h. Move the second inner shell 70 upward to the closed position, and use the second pressure-controlled secondary chamber 71 to accommodate the second mold set 50 .

i. The gas in the second pressure-controlled sub-chamber 71 is firstly pumped out to release the pressure on the embryo in the step g, and then the second mold set 50 is closed.

j. Using the second mold set 50 to cool the preform in the inner finished mold chamber 51 of the second mold set 50 to mold and shape it into a finished product.

Through the description above, the applicant believes that the specific technical content of each of the pressure-controlled secondary chambers 61, 71 provided by the present invention can fully meet the needs of the EVA foam molding process, and make the required extraction The amount of gas is greatly reduced compared with the conventional technology. From an economic point of view, it has the specific effects of saving energy and shortening working hours, and has the effect of flexible use. For example, when the i step is completed, the staff can carry out the first step. The cleaning process of a mold set 40 makes the use of the first and second mold sets 40 and 50 separate, and there will be no lack of mutual restraint and inability to work independently as in the first patent disclosure. Obviously, this The technical content provided by the invention can effectively improve the shortcomings of traditional devices and increase the functions that were originally lacking. It should be a legally claimed invention, and we pray that the patent will be granted as soon as possible.

In addition, the above-opened embodiment is only an illustration of the present invention, and is based on the technical content that is encompassed and equivalent to the scope of the patent application of the present invention. For example, as far as this step c is concerned, although the above-opened embodiment only discloses By means of an external injection molding machine, the EVA raw material is injected into the closed internal blank mold chamber 41 of the first mold group 40 through the extrusion cylinder, but it can also be injected without injection. In the way that the preformed EVA raw material block is filled, under the open state of the first mold group 40, the EVA block is put into the mold cavity for forming the blank mold chamber 41, and then the extraction is carried out. The mold clamping procedure of the gas and the first mold set, that is, these changes do not deviate from the technical features of the present invention, and are still the object for which the applicant wants to claim protection.

Claims (9)

1. A molding method of EVA foam, comprising the following steps: a. Place the first and second molds together in a sealed pressure-controlled main chamber space; b. forming a closed first pressure-controlled sub-chamber in the space of the pressure-controlled main chamber that completely accommodates the first mold and exists independently in the pressure-controlled main chamber; c. Clamp the first mold after removing the gas in the first pressure-controlled sub-chamber, and make the EVA raw material react in the internal closed mold chamber of the first mold after the mold clamping to form an embryo; d. Opening the first voltage-controlled secondary chamber so that the space of the first voltage-controlled secondary chamber becomes a part of the space of the voltage-controlled main chamber; e. Increase the gas pressure in the pressure-controlled main chamber space and maintain the pressure; f. Open the first mold so that the embryo is pressed by the gas pressure of the pressure-controlled main chamber without fully foaming and expanding; g. moving the embryo and filling it into the cavity of the second mold in the mold opening state; h. Forming a closed second pressure-controlled sub-chamber in the space of the pressure-controlled main chamber that completely accommodates the second mold and exists independently in the pressure-controlled main chamber; i. Clamping the second mold after exhausting the gas in the second pressure-controlled secondary chamber; j. Using the second mold, the blank is cooled in the inner mold chamber of the second mold and molded to form a finished product. 2. according to the molding method of the described EVA foam of claim 1, wherein, in c step, this EVA raw material is filled in this first mold by filling mode and when this first mold is under the mold-opening state To form the mold cavity of the closed mold chamber. 3. according to the molding method of the described EVA foam of claim 1, wherein, in c step, this EVA raw material injects in the closed mold chamber in this first mould from the outside after this first mold clamping mold by injection mode . 4. The molding method of EVA foam according to claim 1, wherein the increased gas pressure in step e is maintained at least until step g is completed. 5. A molding device for EVA foam, comprising: A body with a sealable voltage-controlled main chamber space; A first and a second mold group are separately arranged on the machine body and located in the space of the pressure-controlled main chamber; A first inner shell is arranged around the periphery of the first mold group and moves between a closed position and an open position. When located in the closed position, it forms an inner housing that completely accommodates the first mold and exists independently in the press. The closed first voltage-controlled secondary room space in the space of the main control room, and when it is located at the open position, the space enclosed by the first voltage-controlled secondary room is opened to become a part of the voltage-controlled main room space; A second inner shell is arranged on the peripheral side of the second mold group and moves between a closed position and an open position. When located in the closed position, it forms a completely containing the second mold and exists independently in the press. Control the closed second voltage-controlled secondary room space in the space of the main control room, and when it is located at the open position, the space enclosed by the second voltage-controlled secondary room is opened to become a part of the voltage-controlled main room space. 6. according to the molding device of the described EVA foam of claim 5, wherein, this body also comprises: a base; a plate-like top located at a predetermined height above the base; An annular shell part is bridged between the base and the top, and the voltage control main chamber space is located between the shell part, the base and the top. 7. according to the molding device of the described EVA foam of claim 6, wherein, this shell portion has: an annular shell; Two openings are provided through the shell body and respectively correspond to the positions of the first and second mold sets, so as to allow the space of the pressure control main chamber to communicate with the outside world; Two closing plates are slidably arranged on the outer shell wall of the shell body, and slide between a closed position and an open position. When located in the respective closed positions, each of the closing plates respectively closes a corresponding opening, It is used to make the space of the voltage-controlled main chamber closed; and when it is in the open position, the openings are opened. 8. According to the molding device of EVA foam according to claim 7, wherein, the machine body includes two pressing parts for pressing each of the closing plates located at the closed position, so that each of the closing plates is maintained with the shell body The airtight state where the outer shell wall is closely attached. 9. according to the molding device of the described EVA foam of claim 8, wherein, this pressing part also comprises respectively: Two rotating rods are upright and parallel to each other and are respectively arranged on two sides of a corresponding opening; A plurality of hook blocks are respectively symmetrically fixed on the shaft corresponding to the rotating shaft; A driving link is arranged on the top and the top ends of the two rotating rods; A pressure cylinder connected to the drive connecting rod through the output shaft to provide power and make the rotating rods rotate synchronously through the transmission of the driving connecting rod, so that each hook block is hooked on the plate body of the corresponding closing plate , to maintain the airtightness between the closing plate and the shell. the

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