阅读说明：本技术 一种新型蒸汽发泡模具及发泡方法 (Novel steam foaming mold and foaming method ) 是由 迟兴帅 吕冬 余瑶 吴景深 于 2019-01-14 设计创作，主要内容包括：本发明公开了一种新型蒸汽发泡模具,其包括上模组件、下模组件、上模组件和下模组件围成的型腔,该上模组件包括上模盖板和透气钢上模芯,该透气钢上模芯与型腔的上表面接触,透气钢上模芯与上模盖板围成上模空腔；上模组件还包括开口,开口的一端与上模空腔连通,另一端连接至抽真空装置。在上模空腔中设置热传导装置,该热传导装置紧贴透气钢上模芯的上表面。本发明还公开一种利用该蒸汽发泡模具的发泡方法。本发明的蒸汽发泡模具生产制作出的产品具有平滑的上表面,热蒸汽流通性好,型腔内发泡珠粒受热更均匀,能更好地控制蒸汽孔的排气量和排气顺序,从而有利于更好地控制型腔内发泡珠粒的发泡过程。(The invention discloses a novel steam foaming mold which comprises an upper mold component, a lower mold component, and a cavity formed by the upper mold component and the lower mold component in a surrounding manner, wherein the upper mold component comprises an upper mold cover plate and a breathable steel upper mold core, the breathable steel upper mold core is contacted with the upper surface of the cavity, and the breathable steel upper mold core and the upper mold cover plate form an upper mold cavity in a surrounding manner; the upper die assembly further comprises an opening, one end of the opening is communicated with the upper die cavity, and the other end of the opening is connected to the vacuumizing device. And a heat conduction device is arranged in the upper die cavity and is tightly attached to the upper surface of the breathable steel upper die core. The invention also discloses a foaming method using the steam foaming mold. The product produced by the steam foaming mold has a smooth upper surface, the hot steam circulation is good, the foaming beads in the cavity are heated more uniformly, and the exhaust volume and the exhaust sequence of the steam holes can be better controlled, so that the foaming process of the foaming beads in the cavity can be better controlled.)

1. A novel steam foaming mold comprises an upper mold component, a lower mold component, and a cavity formed by the upper mold component and the lower mold component in a surrounding manner, wherein the upper mold component comprises an upper mold cover plate; the upper die assembly further comprises an opening, one end of the opening is communicated with the upper die cavity, and the other end of the opening is connected to a vacuum-pumping device; and a heat conduction device is arranged in the upper die cavity and is tightly attached to the upper surface of the breathable steel upper die core.

2. A steam foaming mold in accordance with claim 1 wherein a flow channel is provided in the heat transfer device.

3. The steam foaming die of claim 2, wherein the flow channel is S-shaped

4. A steam foaming mold according to claim 1 wherein the heat conducting means is provided with a through hole communicating with the upper mold cavity.

5. A steam foaming die according to any of the claims 1-4 wherein the heat conducting means is a copper plate.

6. The steam foaming mold of claim 1, wherein the lower mold assembly comprises a lower mold core, a lower mold cover plate, and a lower mold cavity enclosed by the lower mold core and the lower mold cover plate; a steam pipeline is arranged in the cavity of the lower die, and each branch of the steam pipeline is provided with a steam valve; and a steam hole insert is arranged on the lower mold core, one end of the steam hole insert is communicated with the cavity, and the other end of the steam hole insert is connected to the steam pipeline.

7. A steam foaming mold according to claim 6 wherein the lower mold cavity is further provided with a cooling water pipe and a cooling water nozzle connected to each other.

8. The steam foaming mold of claim 6, wherein the lower mold core is further provided with an air injection probe connected with the steam pipeline.

9. A foaming method using the steam foaming mold according to any one of claims 1 to 9, comprising the steps of:

feeding: adding a raw material to be foamed into the cavity, and closing the die;

introducing steam: connecting the opening with a vacuumizing device, starting the vacuumizing device, and introducing hot steam into the cavity; meanwhile, the heat conduction device is heated to heat the upper breathable steel mold core;

pressure maintaining: closing the opening and the vacuumizing device, and maintaining pressure;

and (3) cooling: the pressure in the cavity is removed, the lower mold core is cooled by cooling water, and the heat conduction device is cooled at the same time, so that the upper mold core of the breathable steel is cooled;

and (6) demolding.

10. The foaming method according to claim 9, further comprising, after the step of maintaining the pressure, the steps of: longitudinally pressurizing the upper die assembly to enable the upper die assembly to move downwards and reduce a die closing gap; and simultaneously, heating the breathable steel upper mold core, and further maintaining the pressure.

Technical Field

The invention relates to a mould and a foaming method for physical foaming by hot steam, in particular to a novel steam foaming mould and a novel steam foaming method, which are used for producing a foaming product with smooth appearance and uniform heating.

Background

The foam plastic has the advantages of light weight, heat insulation, buffering, insulation, corrosion prevention, relatively low price and the like, so the foam plastic is widely applied to the fields of daily necessities, packaging, heat preservation, industry, agriculture, transportation industry, military industry, aerospace industry and the like. The traditional foaming mode adopts a chemical foaming agent for foaming, but the foaming process has great environmental pollution, so that most of the production industries adopt a hot steam physical foaming process at present, thereby avoiding the pollution to the environment and producing the foaming material with higher mechanical property. However, in the conventional physical foaming process, because of the process requirement of steam foaming, steam holes which can be introduced with steam are required to be uniformly arranged on the inner surface of the conventional physical foaming mold, and the purpose is to ensure that the steam can be fully introduced into the mold cavity and can completely penetrate through pre-foaming beads in the mold cavity, so that the pre-foaming beads are heated, and are fused with each other for molding. The outer surface of the product removed from the mold is uniformly lined with dense steam vent marks, resulting in a product that is not smooth on any one surface. Not only can not meet the surface requirements of special products, but also influences the aesthetic feeling of the appearance of the products. If the corresponding steam holes on the inner surface of the mold cavity are directly eliminated in order to achieve the smoothness of one surface in the product, the product is heated unevenly during the forming process, and more defects are generated on the product.

Disclosure of Invention

In view of the above technical problems, an object of the present invention is to provide a novel steam foaming mold and a foaming method, in which a steam permeable insert of an upper mold core in a conventional steam foaming mold is omitted, and the surface of the upper mold core is smooth, so that a product produced by the production process has a smooth surface, is uniformly heated, and has good product quality.

In order to achieve the above object, the present invention adopts the following technical solutions.

The invention provides a novel steam foaming mold which comprises an upper mold component, a lower mold component, and a cavity formed by the upper mold component and the lower mold component, wherein the upper mold component comprises an upper mold cover plate and a breathable steel upper mold core, the breathable steel upper mold core is contacted with the upper surface of the cavity, and the breathable steel upper mold core and the upper mold cover plate form an upper mold cavity; the upper die assembly further comprises an opening, the opening can be arranged on the upper die cover plate, one end of the opening is communicated with the upper die cavity, and the other end of the opening is connected to the vacuumizing device. And a heat conduction device is arranged in the upper die cavity and is tightly attached to the upper surface of the breathable steel upper die core, so that the breathable steel upper die core is heated or cooled by utilizing heat conduction. The air-permeable steel upper mold core substantially encloses the upper surface of the mold cavity, which is the side facing the upper mold core. The air permeable steel is air permeable steel, is an existing commercial product, and has a smooth surface. So make the surface of mould towards the die cavity upper surface smooth, relative to the mould surface distribution steam hole among the prior art, the foaming goods upper surface that obtains is more smooth. Through the vacuum pumping device, the pressure difference is formed in the upper die cavity, so that steam is promoted to circulate and is uniformly distributed, and the pre-foaming beads are uniformly heated.

Furthermore, a flow channel is arranged in the heat conduction device. The gas permeable steel upper core may be heated or cooled by flowing a fluid, such as hot or cold oil, through the flow passages.

Further, the flow passage is S-shaped. The S-shaped flow channel increases the contact area between the fluid and the heat conduction device, so that the heat conduction effect is better.

Further, the heat conduction device is provided with a through hole which is communicated with the upper die cavity. The through hole is beneficial to keeping the same pressure on the heat conduction device, and when the upper die cavity is negative pressure, the water vapor can pass through the upper die core of the breathable steel from the lower part of the upper die core of the breathable steel and enter the upper die cavity through the through hole, so that the foaming beads in the die cavity are heated more uniformly. The larger total area of the through holes further facilitates sufficient exposure of the upper surface of the breather steel to the upper mold cavity to maintain air communication with the upper mold cavity, preferably greater than one-half the surface area of the heat transfer device.

Further, the heat conduction means is a copper plate.

Furthermore, the lower die assembly comprises a lower die core, a lower die cover plate and a lower die cavity enclosed by the lower die core and the lower die cover plate, a steam pipeline is arranged in the lower die cavity, and each branch of the steam pipeline is provided with a steam valve respectively so as to control the air displacement and the air exhaust sequence of the steam holes. The lower mold core is provided with a steam hole insert, one end of the steam hole insert is communicated with the cavity, and the other end of the steam hole insert is connected to a steam pipeline.

Furthermore, a cooling water pipeline and a cooling water spray head which are connected with each other are also arranged in the cavity of the lower die and are used for cooling the lower die core.

Furthermore, an air injection probe connected with a steam pipeline is also arranged on the lower mold core. To the product position of being thicker, perhaps the position that steam is difficult for flowing, install the jet-propelled probe additional, probe one end stretches into the position that steam is difficult for flowing, and the other end is connected with steam pipe, thereby supplementary steam circulation makes the hot steam who lets in the mould die cavity can reach controllable degree according to the production needs, ensures that steam can be even, and heats the pre-expanded bead in the die cavity completely.

The invention also provides a foaming method using the steam foaming mold, which comprises the following steps:

feeding: adding a raw material to be foamed into the cavity, and closing the die;

introducing steam: connecting the opening with a vacuumizing device, starting the vacuumizing device, and introducing hot steam into the cavity; meanwhile, the heat conduction device is heated to heat the upper breathable steel mold core;

pressure maintaining: closing the opening and the vacuumizing device, and maintaining pressure;

and (3) cooling: the pressure in the cavity is removed, the lower mold core is cooled by cooling water, and the heat conduction device is cooled at the same time, so that the upper mold core of the breathable steel is cooled;

and (6) demolding.

Further, after the step of maintaining the pressure, the method further comprises the steps of: longitudinally pressurizing the upper die assembly to enable the upper die assembly to move downwards so as to reduce a die closing gap; and meanwhile, heating the upper breathable steel mold core, and further maintaining the pressure. According to different raw materials, different heating temperatures, heating rates and holding times can be set. The cooling and demolding steps described above are then continued. Thus, the thickness of the crust on the surface of the foamed product can be changed and the smoothness can be improved.

The invention has the advantages of

(1) The upper mold core made of the breathable steel is adopted to replace the traditional upper mold core provided with the steam hole insert, so that a smooth surface without steam holes is obtained, and the produced product has a smooth upper surface.

(2) The hot steam circulation is good, and the foaming beads in the cavity are heated more uniformly.

(3) The exhaust volume and the exhaust sequence of the steam holes can be better controlled, thereby being beneficial to better controlling the foaming process of the foaming beads in the cavity.

Drawings

Fig. 1 is a sectional view of an upper mold assembly of a steam foaming mold according to an embodiment of the present invention;

FIG. 2 is another cross-sectional view of the upper die assembly of the steam foaming die of the embodiment of the present invention;

fig. 3 is a sectional view of a lower mold assembly of a steam foaming mold according to an embodiment of the present invention;

fig. 4 is a sectional view of the steam foaming mold after clamping according to the embodiment of the present invention.

Wherein:

1-Upper die Assembly

2-lower die assembly

3-die cavity

4-Upper die cover plate

5-ventilating steel upper mold core

6-Upper die Cavity

7-opening

8-copper plate

9-flow channel

10-through hole

11-lower die cover plate

12-lower die core

13-lower die cavity

14-steam line

15-steam valve

16-steam hole insert

17-Cooling Water line

18-water drain valve

19-pressure relief valve

20-die gap

21-sealing strip

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1-4, a novel steam foaming mold comprises an upper mold component 1, a lower mold component 2, a mold cavity 3 enclosed by the upper mold component and the lower mold component, wherein the upper mold component 1 comprises an upper mold cover plate 4, an upper breathable steel mold core 5, the upper breathable steel mold core 5 and the upper mold cover plate 4 enclose an upper mold cavity 6, the upper breathable steel mold core 5 is in contact with the upper surface of the mold cavity 3, and the smoothness of the surface of the mold cavity 3 close to the mold cavity is Ra < 0.2. An opening 7 is provided in the upper die cover plate 4, one end of the opening 7 communicating with the upper die cavity 6 and the other end connected to a vacuum pump (not shown). A copper plate 8 is provided in the upper mold cavity 6 in close contact with the upper surface of the air-permeable steel upper mold core 5, and serves as a heat conduction device for heating or cooling the air-permeable steel upper mold core 5 by heat conduction. An S-shaped flow passage 9 and a through hole 10 are provided in the copper plate 8. The through hole 10 communicates with the upper mold cavity 6, and the opening area thereof is two thirds of the surface area of the copper plate 8. Those skilled in the art will appreciate that the through hole 10 is disposed to avoid the flow channel 9.

The lower die assembly 2 comprises a lower die cover plate 11, a lower die core 12 and a lower die cavity 13 enclosed by the lower die core 12 and the lower die cover plate 11, a steam pipeline 14 is arranged in the lower die cavity 13, and each branch of the steam pipeline 14 is provided with a steam valve 15 respectively so as to control the air displacement and the air exhaust sequence of the steam holes. The lower mold core 12 is provided with a steam hole insert 16 and a gas injection probe (not shown), one end of the steam hole insert 16 is communicated with the mold cavity 3, the other end is connected to the steam pipeline 14, and one end of the gas injection probe is connected to the steam pipeline 14. The lower mold cavity 13 is also provided with a cooling water pipe 17 and a cooling water shower head which are connected with each other.

The specific foaming process is described in detail below, and the foaming process flow is as follows: charging, introducing steam, maintaining pressure, cooling and demoulding.

Feeding: adding the pre-expanded beads into the cavity 3, closing the mold, wherein the mold closing position is determined according to the thickness requirement of the product, and the mold closing gap 20 is adjusted.

Introducing steam: and connecting the opening 7 with a vacuum pump, starting the vacuum pump to enable the upper die cavity 6 above the air-permeable steel upper die core 5 to be in a negative pressure state, and generating pressure difference between the upper die cavity 6 above and below the air-permeable steel upper die core 5 and the die cavity 3 to enable air to pass through the air-permeable steel upper die core 5 from the die cavity 3 to reach the upper die cavity and finally to be discharged into a collector through the through hole 10 by the vacuum pump. Meanwhile, under the control of each branch steam valve 15, heating steam is discharged into the cavity 3 from a steam pipeline 14 arranged in the lower die cavity 13 sequentially through a steam hole insert 16 and a steam injection probe, and passes through the breathable steel upper die core 5 to enter the upper die cavity. The effect that reaches is that the air in the die cavity 3 is discharged completely, and hot steam is discharged into the die cavity 3 through lower mold core 12 for hot steam pierces through the pre-expanded bead in die cavity 3, heats the pre-expanded bead. Meanwhile, a rapid cooling and rapid heating device, such as a mold temperature controller, is adopted to introduce hot oil into the flow channel 9 of the copper plate 8 to heat the upper mold core 5 of the breathable steel.

Pressure maintaining: after the cavity 3 is filled with hot steam, the vacuum pump and the opening 7 are closed, and the cooling water line 17 in the cavity 13 of the lower mold is closed and sealed at the mold junction with the sealing strip 21. After the upper and lower dies are closed, the upper die cavity 6, the lower die cavity 13 and the die cavity 3 are all in the same closed environment. The steam generating device (not shown) connected to the steam line 14 is controlled to continue to emit hot steam to pressurize the cavity 3, and when a desired pressure is reached, preferably 0.3-1.2MPa, more preferably 0.4MPa, the steam generating device is turned off and maintained at a constant pressure for 5 minutes.

And (3) cooling: first, the drain valve 19 is opened to release the pressure inside the cavity 3, and the drain valve 18 on the lower mold cover plate is opened to drain the cooling shower water inside the lower mold cavity out of the mold. And simultaneously cooling the upper die and the lower die.

Cooling the lower die: connecting a cooling water pipeline 17 in the lower die cavity 13 with an external cooling water pipeline, introducing cooling water, enabling the cooling water to reach cooling water spray heads uniformly distributed at the end of the cooling water pipeline 17 through the cooling water pipeline 17, spraying the cooling water onto the lower surface of the lower die core 12, namely the surface in contact with the lower die cavity 13 through the cooling water spray heads, and thus meeting the requirement of cooling the lower die and a product;

cooling an upper die: the upper mold core 5 of the gas permeable steel is cooled by heat transfer by introducing cold oil into the internal flow passage 9 of the copper plate 8 using a rapid cooling and rapid heating device such as a mold temperature machine.

So that the upper mold core 5, the lower mold core 12 and the product in the cavity 3 are simultaneously cooled and lowered to the demolding temperature.

Demolding: and when the temperature of the products in the upper breathable steel mold core 5, the lower mold core 12 and the mold cavity 3 is reduced to the demolding temperature, the upper mold is lifted and fixed by adopting a hydraulic device, and then the products in the mold cavity 3 are taken out.

After foaming and forming, the surface skinning thickness of the foaming product can be changed and the smoothness can be improved by adjusting the die closing gap 20 and the temperature of the upper die core 5 of the breathable steel. After the pre-expanded beads in the mold cavity 3 are heated and molded, the thickness of the crust on the surface of the expanded material can be increased in order to improve the surface smoothness and mechanical properties of the product. The specific operation is as follows: the upper die assembly 1 is longitudinally pressurized through a hydraulic device, so that the upper die assembly 1 moves downwards, the running distance can be determined according to the product requirement, and the downward running distance is measured through the numerical value of the die closing gap 20. Meanwhile, the upper mold core 5 of the air-permeable steel is heated, a quenching and rapid heating device is also adopted, heated fluid is introduced into the internal flow channel 9 of the copper plate 8, different heating temperatures, heating rates and heat preservation time can be set according to different raw materials, then cold fluid is introduced into the flow channel 9 inside the copper plate 8, and cooling is carried out, so that the foaming material with smooth surface, no weld mark and high strength can be manufactured.

It should be understood that the above-mentioned examples of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. It is not intended to be exhaustive or to limit all embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. All obvious changes and modifications which are within the technical scope of the invention are covered by the invention.