CN-121973995-A - Graded pressure release vacuumizing method and device for aluminum foil coated nanometer heat insulation plate

CN121973995ACN 121973995 ACN121973995 ACN 121973995ACN-121973995-A

Abstract

The invention relates to a grading pressure release vacuumizing method and device for an aluminum foil coated nanometer heat insulation plate, which comprises the specific steps of S1, placing an aluminum foil vacuum bag with the nanometer heat insulation plate inside the vacuumizing device, enabling a bag opening to be positioned at a heat sealing station of the vacuumizing device, S2, covering a silica gel plate above the aluminum foil vacuum bag, S3, starting the vacuumizing device to vacuumize the inside of the aluminum foil vacuum bag, applying micro vibration to the areas where a first air cavity and a second air cavity are located in the vacuumizing process, S4, driving a heat seal to seal the bag opening in a heat pressing mode after vacuumizing reaches a preset vacuum degree, and S5, enabling the whole silica gel plate to cool the bag body in a pressure maintaining mode after heat sealing is completed. The vacuum heat insulation packaging method has the advantages that the bag mouth warpage, dislocation or fold in the bag mouth area is avoided, the air exhaust smoothness, the closing stability and the heat sealing strength of the bag mouth area are ensured, and the vacuum heat insulation packaging performance of the metal-based aluminum foil bag mouth is remarkably improved.

Inventors

CHEN XIAOGANG
ZHANG JUN
ZHANG GUI
SHEN YANG
ZHONG YAJUN
LI XING
HUANG YUE

Assignees

南通福美新材料有限公司

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (10)

1. A grading pressure release vacuumizing method of an aluminum foil coated nanometer heat insulation plate is characterized by comprising the following specific steps of, S1, placing an aluminum foil vacuum bag with a nano heat insulation plate inside in a vacuumizing device, and positioning a bag opening at a heat sealing station of the vacuumizing device; S2, covering a silica gel plate above the aluminum foil vacuum bag, wherein a first air cavity, a second air cavity and a third air cavity which are sequentially and independently distributed along the direction of the bag opening and can be independently inflated are arranged in the silica gel plate, and the third air cavity is arranged adjacent to the bag opening; S3, starting a vacuumizing device to vacuumize the inside of the aluminum foil vacuum bag, filling compressed air into the first air cavity and the second air cavity in the vacuumizing process to enable the first air cavity and the second air cavity to apply a first compacting force to the aluminum foil vacuum bag, and simultaneously filling compressed air into the third air cavity to enable the third air cavity to apply a second compacting force lower than the first compacting force to the aluminum foil vacuum bag, so that the aluminum foil vacuum bag in the bag opening direction is in a low constraint state; s4, after vacuumizing reaches a preset vacuum degree, driving the heat seal to carry out heat pressing sealing on the bag opening, and releasing pressure of the third air cavity at the moment that the heat seal presses the bag opening, so that the pressure of the third air cavity on the bag body is reduced to zero, and the bag opening area is completely separated from the constraint of the silica gel plate; S5, after the heat sealing is finished, the third air cavity is refilled with compressed air, so that the pressure of the third air cavity is restored to be the same as that of the first air cavity and the second air cavity, and the whole silica gel plate is used for pressure maintaining and cooling of the bag body.
2. The method for carrying out graded pressure release and vacuumizing on the aluminum foil covered nano heat insulation plate according to claim 1, wherein the second pressing force of the third air cavity in the step S3 is 15% -20% of the first pressing force of the first air cavity, and the time for pressing the bag mouth by the heat seal in the step S4 lags the time for reducing the pressure of the third air cavity to zero by 0.2-0.5 seconds, so that the bag mouth area is ensured to bear the heat seal pressure in a complete free state.
3. The method for carrying out graded pressure release and vacuum pumping on the aluminum foil coated nanometer heat insulation plate according to claim 2, wherein in the step S3, the frequency of applying micro vibration to the area where the first air cavity and the second air cavity of the silica gel plate are located in the vacuum pumping process is 30-80Hz, and the amplitude is 0.05-0.15mm.
4. A graded pressure release vacuumizing device for implementing the aluminum foil coated nanometer heat insulation plate as claimed in any one of claims 1-3, which is characterized by comprising The vacuum cavity is internally provided with a heat sealing station, a bag opening of an aluminum foil vacuum bag with a built-in nanometer heat insulation plate is arranged on the heat sealing station, and a vacuum generator for vacuumizing the inside of the vacuum cavity is arranged outside the vacuum cavity; the heat sealing group comprises a heat sealing strip arranged on a heat sealing station and a heat sealing pressing block arranged in the vacuum cavity, and the heat sealing pressing block is arranged right above the heat sealing strip and is lifted up and down through a first driving cylinder; The micro-amplitude vibration pressing plate group comprises a rigid pressing plate connected with the driving end of the driving cylinder II and a silica gel plate arranged on the lower end surface of the rigid pressing plate, a first air cavity, a second air cavity and a third air cavity are sequentially and independently distributed at the inner lower side position of the silica gel plate along the direction of a bag opening, the third air cavity is arranged close to the bag opening, physical isolation is realized between the air cavities through an elastic sealing separation part, and a micro-amplitude vibration generator is arranged at the upper end of the rigid pressing plate; the pressure detection unit is a first pressure sensor arranged on the rigid pressing plate and used for detecting the pressing force of the micro-amplitude vibration pressing plate group contacted with the aluminum foil vacuum bag in real time; The partition pressure control unit is respectively communicated with the first air cavity, the second air cavity and the third air cavity of the silica gel plate, and independently controls the pressure of compressed gas filled into each air cavity so as to adjust the pressure applied by each air cavity to the aluminum foil vacuum bag; The control unit is electrically connected with the vacuum generator, the heat sealing group, the micro-amplitude vibration pressing plate group, the pressure detection unit and the partition pressure control unit.
5. The hierarchical pressure-releasing vacuum pumping device of aluminum foil covered nanometer heat insulation plate as set forth in claim 4, wherein the control unit performs the following control sequences (1) The controller controls the driving cylinder II to drive the rigid pressing plate to descend, and when the pressing force detected by the pressure sensor I reaches a preset contact pressure threshold value, the pressing action of the driving cylinder II is stopped, so that the silica gel plate and the surface of the aluminum foil vacuum bag are kept in a contact state; (2) Controlling the pressure of the first air cavity and the second air cavity to be a first compression force P1, controlling the pressure of the third air cavity to be a second compression force P2, wherein P2=0.15P1-0.2P1, and starting a micro amplitude vibration generator to apply micro amplitude vibration to the first air cavity and the second air cavity in the vacuumizing process; (3) Controlling the driving cylinder to descend at the moment of heat sealing to enable the heat sealing pressing block to press the bag opening of the aluminum foil vacuum bag, and controlling the third air cavity to release pressure to zero at the moment of pressing, wherein the first air cavity and the second air cavity keep pressure P1; (4) And a pressure maintaining and cooling stage, namely after the heat sealing is finished, controlling the pressure of the third air cavity to be restored to P1, and enabling the whole silica gel plate to maintain the pressure and cool the aluminum foil vacuum bag.
6. The grading pressure-releasing vacuumizing device of the aluminum foil covered nano heat-insulating plate according to claim 5, wherein a flexible joint is arranged between the driving end of the second driving cylinder and the rigid pressing plate, a guide column is arranged between the rigid pressing plate and the inner wall of the vacuum cavity, and the extending direction of the guide column is consistent with the extending direction of the second driving cylinder.
7. The grading pressure-releasing vacuumizing device of the aluminum foil covered nano heat-insulating plate according to claim 6, wherein the partition pressure control unit comprises an air source and air pressure regulating branches respectively communicated with a first air cavity, a second air cavity and a third air cavity of the silica gel plate, and each air pressure regulating branch is connected in series with an electric proportional valve between the air source and the corresponding air cavity and a second pressure sensor for detecting the pressure of the corresponding air cavity; the control unit receives actual pressure signals detected by the pressure sensors II, compares the actual pressure values with preset target pressure values, controls the opening of the electric proportional valves, and realizes independent closed-loop adjustment of the pressure of each air cavity.
8. The grading pressure-releasing vacuumizing device of the aluminum foil-coated nanometer heat insulation plate, which is characterized in that the micro amplitude vibration generator is an electromagnetic vibration exciter, a first frequency f1=50-80 Hz is applied when the micro amplitude vibration generator is started in the early stage of vacuumizing, the micro amplitude vibration generator is automatically switched to a second frequency f2=30-50 Hz according to a vacuum degree detection value in the middle stage of vacuumizing, and the micro amplitude vibration generator is closed when the vacuum degree reaches a preset value in the later stage of vacuumizing.
9. The grading pressure-releasing vacuumizing device of the aluminum foil covered nano heat-insulating plate according to claim 8, wherein a plurality of air exhaust grooves are formed in the lower surface of the silica gel plate, and the air exhaust grooves are arranged close to the third air cavity.
10. The grading pressure-releasing vacuumizing device of the aluminum foil covered nano heat-insulating plate according to claim 9, wherein the outer side end face of the heat-sealing pressing block is provided with a high-temperature-resistant elastic cushion layer, the thickness of the high-temperature-resistant elastic cushion layer is 1-3mm, and the hardness of the high-temperature-resistant elastic cushion layer is 30-50 degrees Shore A.

Description

Graded pressure release vacuumizing method and device for aluminum foil coated nanometer heat insulation plate Technical Field The invention relates to the field of vacuum packaging of new materials, in particular to a grading pressure-releasing vacuumizing method and device for an aluminum foil coated nanometer heat-insulating plate, which are particularly suitable for a vacuum packaging device in high-end equipment manufacturing and a new material post-treatment process. Background The nanometer microporous heat insulating board is a novel high-efficiency heat insulating material which is prepared by taking fumed silica as a base material, adding infrared opacifying agent and other functional components and adopting a special forming process, and has wide application prospect in the emerging industries of aerospace, industrial energy conservation, building heat preservation, high-end equipment manufacturing and the like. The nanometer microporous heat-insulating plate has extremely strong moisture absorption characteristic, and can rapidly absorb moisture when being exposed to the ambient air, so that the heat-insulating performance of the nanometer microporous heat-insulating plate is obviously deteriorated, and the long-term reliability of the nanometer microporous heat-insulating plate in a high-end application scene is seriously influenced. In order to solve the technical problem, an aluminum foil vacuum bag is generally adopted in industry to carry out vacuum coating and packaging, and a stable vacuum isolation layer is formed by pumping air in the bag and thermally sealing the bag mouth, so that the heat insulation performance and the service life of the nanometer heat insulation plate are ensured. In the existing aluminum foil vacuum bag coating process, in order to ensure the flatness of the bag body, avoid the aluminum foil wrinkles and promote the gas discharge in the bag in the vacuumizing process, a silica gel plate is usually required to be placed above the aluminum foil vacuum bag. The silica gel plate has good elasticity and flexibility, and can apply uniform pressure to the bag body, so that the aluminum foil bag is tightly attached to the surface of the nanometer heat insulation plate, and the gas residual space is reduced. Meanwhile, the silica gel plate can play a role in buffering in the vacuumizing process, and the nano heat insulation plate is prevented from being broken or an aluminum foil bag is prevented from being damaged due to overlarge pressing force. In addition, when the bag mouth is sealed, the silica gel plate can assist in fixing the bag body, so that the alignment of the bag mouth is ensured, and the heat sealing quality is improved. However, in practice, it has been found that the above-mentioned manner of directly placing the silicone plate over the aluminum foil vacuum bag for vacuum pumping has the following technical drawbacks: 1. The silica gel plate is a monolithic structure, and the pressure applied to the bag body is uniform. In the vacuumizing process, the bag opening area needs to keep a certain degree of freedom so that the bag opening can be naturally closed before heat sealing, but the bag opening area is also greatly restrained due to the uniform pressure of the whole silica gel plate, and the bag opening is difficult to form an ideal closing state in the later period of vacuumizing. In actual operation, the phenomena of warping, dislocation or wrinkling of the bag mouth are common, the subsequent heat sealing quality is seriously affected, the heat sealing line is not tightly sealed, and even the problem of air leakage occurs; 2. The interior of the nanometer microporous heat-insulating plate contains a large number of micro-nano scale pores, and gas molecules have physical adsorption phenomenon on the inner walls of the pores. The conventional vacuumizing mode only depends on vacuum negative pressure to discharge free gas, so that gas molecules adsorbed on the inner wall of the pore are difficult to effectively desorb. The residual gases can be slowly released in the use process after the product is packaged, so that the vacuum degree in the bag is gradually reduced along with the time, and the effective service life of the product is shortened; 3. when the silica gel plate is moved away in advance, the bag body is possibly shifted in a vacuumizing state, so that the bag mouth deviates from a heat sealing station, and pressure maintaining cooling cannot be carried out on the bag body. Disclosure of Invention The invention aims to overcome the defects, and provides a grading pressure-releasing vacuumizing method and device for an aluminum foil coated nanometer heat-insulating plate, which effectively solve the technical problems. The invention aims at realizing the technical scheme that the grading pressure-releasing vacuumizing method of the aluminum foil coated nanometer heat-insulating plate comprises the following specific steps, S1, placing an alumin