CN111873486A

CN111873486A - Forming method of large-size and large-thickness rigid aerogel component

Info

Publication number: CN111873486A
Application number: CN202010753896.6A
Authority: CN
Inventors: 高庆福; 李勇; 李思武; 杨斌; 熊熙
Original assignee: Hunan Ronglan Intelligent Technology Co ltd
Current assignee: Hunan Ronglan Intelligent Technology Co ltd
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2020-11-03

Abstract

The invention relates to a method for forming a large-size and large-thickness rigid aerogel component, which comprises the following steps: preparing a forming mold, a vacuum impregnation device, a shaped fiber body, a plurality of flexible cotton felts, an autoclave and sol; arranging the shaped fiber body in a forming die, and adding a vacuum impregnation device into a sol barrel; the forming mould is arranged on the vacuum impregnation device; starting a vacuum impregnation device to perform impregnation treatment; placing the forming die in a high-pressure kettle for supercritical drying; and taking out the formed aerogel component and trimming. The method can be used for conveniently manufacturing the large-size and large-thickness rigid aerogel component without the conditions of uneven thickness, cracking, poor roughness and the like, can effectively improve the manufacturing quality of the aerogel component, does not need special vacuum impregnation equipment in the impregnation process, and has the advantages of simple operation, high sol impregnation efficiency, high sol utilization rate, high processing efficiency, low cost and the like.

Description

Forming method of large-size and large-thickness rigid aerogel component

Technical Field

The invention relates to a method for forming an aerogel component.

Background

The aerogel serving as a novel high-efficiency heat insulation material has the characteristics of high temperature resistance, light weight, good mechanical property, good forming property and the like, and has a wide application prospect in the field of aerospace. Because positions such as profiles such as novel aircraft, cabin body structure are complicated, need vibration-resistant simultaneously in the use, and flexible aerogel heat insulation felt falls to powder seriously, and the vibration performance is not good, is difficult to use, consequently, the rigidity aerogel thermal insulation material that the urgent need has certain shape can guarantee that the laminating of aerogel profile and metal cabin body profile is good, can be able to bear or endure harsh requirements such as vibration, impact in the use. Because the existing aerogel component is mostly formed by positioning and shaping a fiber body through a forming die, then introducing sol into the die through special dipping equipment, and then dipping and shaping the fiber body with the sol, the existing forming die has the condition of insufficient structural design, so that the aerogel component is easy to have the condition of unstable forming, the aerogel component is easy to have the conditions of uneven thickness, cracking and poor roughness, and the sol utilization rate is low; and the existing aerogel member forming method also has the defects of great operation difficulty, time and cost waste in processing.

Disclosure of Invention

The invention aims to solve the problems and the defects, and provides a method for forming a large-size and large-thickness rigid aerogel component, which can be used for conveniently manufacturing the large-size and large-thickness rigid aerogel component without the conditions of uneven thickness, cracking, poor roughness and the like, can effectively improve the manufacturing quality of the aerogel component, does not need special vacuum impregnation equipment in the impregnation process, and has the advantages of simple operation, high sol impregnation efficiency, high sol utilization rate, high processing efficiency, low cost and the like, and the method for processing the component with larger size has more obvious advantages.

The technical scheme of the invention is realized as follows:

a method for forming a large-size and large-thickness rigid aerogel component is characterized by comprising the following steps:

(1) preparing: preparing a forming mold, a vacuum impregnation device, a shaped fiber body, a plurality of flexible cotton felts, an autoclave and sol; the forming die comprises a male die body, a female die body, two positioning pins and a plurality of locking bolts, wherein the male die body and the female die body are made of carbon steel or die steel or stainless steel or aluminum alloy, the surfaces of the male die body and the female die body are galvanized or Cr-plated, a male die part is arranged on the lower surface of the male die body, a first trimming groove in an annular shape is arranged on the lower surface of the male die body, the first trimming groove surrounds the male die part, a first diversion groove and a second diversion groove are respectively arranged on the lower surface of the male die body, the first diversion groove and the second diversion groove are respectively positioned at the left side and the right side of the male die part, the first diversion groove and the second diversion groove respectively extend to the left surface and the right surface of the male die body, the first diversion groove and the second diversion groove are communicated with the first trimming groove, and a plurality of first glue dipping grooves in a strip shape are uniformly arranged on the upper surface of the male die body, and each first glue dipping groove extends longitudinally, the front end and the rear end of each first glue dipping groove respectively extend to the front surface and the rear surface of the male die body, the width of each first glue dipping groove is 10-20 mm, the depth of each first glue dipping groove is 5-20 mm, a plurality of first glue dipping holes penetrating to the male die part are uniformly formed in the bottom of each first glue dipping groove, the first glue dipping holes in the same first glue dipping groove are arranged side by side along the length direction of the first glue dipping groove, the aperture of each first glue dipping hole is 3-6 mm, the distance between two adjacent first glue dipping holes in the same first glue dipping groove is 30-100 mm, a female die part is arranged on the upper surface of the female die body, an annular second trimming groove is formed on the upper surface of the female die body, a third diversion groove and a fourth diversion groove are respectively formed on the upper surface of the female die body, and the third diversion trench and the fourth diversion trench are respectively positioned at the left side and the right side of the female die part, the third diversion trench and the fourth diversion trench are respectively extended to the left surface and the right surface of the female die body, the third diversion trench and the fourth diversion trench are respectively communicated with the second trimming groove, a plurality of strip-shaped second glue dipping grooves are uniformly arranged on the lower surface of the female die body, the second glue dipping grooves are longitudinally extended, the front end and the rear end of each second glue dipping groove are respectively extended to the front surface and the rear surface of the female die body, the width of each second glue dipping groove is 10-20 mm, the depth of each second glue dipping groove is 5-20 mm, a plurality of second glue dipping holes penetrating through the female die part are uniformly arranged at the bottom of each second glue dipping groove, the second glue dipping holes in the same second glue dipping groove are arranged side by side along the length direction of the second glue dipping grooves, and the aperture of each second glue dipping hole is 3-6 mm, the distance between two adjacent second glue dipping holes in the same second glue dipping groove is 30-100 mm, the male die body is covered on the upper surface of the female die body, a forming cavity is formed between the male die part and the female die part, the diameters of the two positioning pins are 6-20 mm, the two positioning pins are inserted in the male die body side by side, the two positioning pins are respectively positioned at the front side and the rear side of the male die part, the two positioning pins are also inserted in the female die body, and each locking bolt penetrates through the male die body and the female die body and then is locked; the vacuum impregnation device comprises a rack, a sol barrel, a vacuum pump, a vacuum bag, a vacuum pumping pipe, an impregnation pipe, a vacuum pressure gauge, a vacuum valve and an impregnation valve, wherein a placing inner cavity is arranged on the vacuum bag, the sol barrel, the vacuum pump and the vacuum bag are arranged on the rack, one end of the vacuum pumping pipe is connected to the vacuum pump, the other end of the vacuum pumping pipe penetrates through the vacuum bag, a pipe orifice at the other end of the vacuum pumping pipe penetrates through the upper part of the placing inner cavity, the vacuum pressure gauge and the vacuum valve are connected in series on the vacuum pumping pipe and are positioned at one end close to the vacuum pump, one end of the impregnation pipe penetrates through the sol barrel, the other end of the impregnation pipe penetrates through the vacuum bag, a pipe orifice at the other end of the impregnation pipe penetrates through the lower part of the placing inner cavity, and the impregnation;

(2) placing a shaped fiber body and releasing sol: arranging the shaped fiber body in a forming cavity, and adding sol into a sol barrel;

(3) packaging and forming the die: wrapping each corner of the forming mould by using a flexible cotton felt, then vertically placing the forming mould in a placing inner cavity of a vacuum bag, and also vertically arranging a first glue dipping groove;

(4) vacuum impregnation: the vacuum bag is in a room temperature environment; opening a vacuum valve, closing the impregnation valve, then opening the vacuum pump, and keeping the pressure for at least 5min when the vacuum degree in the placing inner cavity reaches-0.09 MPa to-0.1 MPa; then closing the vacuum valve and opening the dipping valve, and allowing the sol to enter the placing inner cavity and the molding cavity along the dipping pipe; after the sol is completely impregnated, closing the impregnation valve, and aging the sol for gelation;

(5) supercritical drying: taking out the forming mold from the vacuum bag, and then placing the forming mold in a high-pressure kettle for supercritical drying, wherein ethanol or carbon dioxide is used as a drying medium for supercritical drying;

(6) processing: and (4) disassembling the forming die, taking out the formed aerogel component, and trimming to obtain the required aerogel component.

Preferably, the aperture of each first glue dipping hole and the aperture of each second glue dipping hole are 5mm, the distance between two adjacent first glue dipping holes in the same first glue dipping tank is 50mm, the distance between two adjacent second glue dipping holes in the same second glue dipping tank is 50mm, and the diameter of each positioning pin is 10 mm.

Preferably, a plurality of groove of stepping down have been seted up on the top surface of the die body, a plurality of constant head tanks have been seted up on the bottom surface of the die body to make the position of each constant head tank and the position one-to-one of each groove of stepping down, the nut of each locking bolt is arranged respectively in the groove of stepping down, and the nut end of each locking bolt inlays respectively in the constant head tank, and the screw rod of each locking bolt passes behind die body, the die body and the corresponding nut looks spiro union, be equipped with the screw hole on the front surface of die body and the die body respectively.

The invention has the beneficial effects that: in the method for forming the large-size and large-thickness rigid aerogel member, the male die body and the female die body are made of carbon steel or die steel or stainless steel or aluminum alloy, so that the male die body and the female die body have high structural strength, and the surfaces of the male die body and the female die body are plated with zinc or Cr, so that the rusting of the die can be avoided, and the service life of the die is prolonged. Through the first steeping vat, first steeping hole, the second steeping vat, the second steeping hole, first edging groove, the second edging groove, first guiding gutter, the second guiding gutter, the third guiding gutter, offer of fourth guiding gutter, can improve the stability and the homogeneity that sol entered into the shaping chamber greatly like this, thereby help improving the jumbo size, the fashioned stability of big thickness rigidity aerogel component, in order to avoid the jumbo size, the thick inequality appears in big thickness rigidity aerogel component, the fracture, the roughness difference circumstances such as, and then can improve the jumbo size greatly, the shaping quality of big thickness rigidity aerogel component. Set up through first edging groove, second edging groove can not only play the purpose of guide sol, can also make things convenient for the follow-up side to the aerogel component to repair to help improving the processingquality of aerogel component. The forming mold is vertically placed in the placing inner cavity, and the first glue dipping grooves are vertically arranged, so that all the first glue dipping grooves and all the second glue dipping grooves are vertically arranged, and the notches of the first trimming grooves and the second trimming grooves on the surface of the forming mold are also arranged side by side left and right or front and back; in addition, the other end pipe orifice of the vacuumizing pipe and the other end pipe orifice of the dip pipe are arranged up and down, so that the stability of vacuumizing can be ensured, and the sol can be dipped in the forming die from bottom to top when the sol is introduced through the dip pipe; therefore, the sol can more conveniently form notches through the first trimming groove and the second trimming groove, each first glue dipping groove, each second glue dipping groove, each first glue dipping hole and each second glue dipping hole, and the first diversion trench, the second diversion trench, the third diversion trench, the fourth diversion trench is very smooth and stably enters the molding cavity, the molding fiber body in the molding cavity can be impregnated through the sol, the impregnating stability and the impregnating comprehensiveness can be greatly improved, a large-size and large-thickness rigid aerogel component can be quickly formed, the conditions that the thickness of the aerogel component is uneven, cracks, the roughness is poor and the like are avoided, and the molding quality of the aerogel component can be greatly improved. The corners of the forming mould are wrapped by the flexible cotton felt, so that the vacuum bag can be prevented from being punctured by the corners of the forming mould, the air leakage of the vacuum bag can be avoided, and the reliability of the impregnation effect can be improved. After the dipping valve is opened, the sol to be dipped is siphoned into the forming cavity through vacuum, and the sol is dipped into the shaped fiber body from bottom to top through the holes on the two sides of the forming mold, each dipping groove and each dipping hole of the forming mold, so that the channels for dipping the sol are greatly increased, the large-size and large-thickness shaped fiber body can be effectively and fully dipped, and the processing quality of the large-size and large-thickness rigid aerogel component is improved. The vacuum impregnation treatment is carried out by adopting a mode of sleeving the forming die with the vacuum bag, so that special vacuum impregnation equipment is not needed in the impregnation process, the sol loss is very little, the utilization rate of the sol can be greatly improved, the process is very simple, a special vacuum impregnation tank is not needed, the cost is lower, the method is convenient and fast, the forming method has the advantages of simplicity in operation, high processing efficiency, low cost and the like, the size precision of the molded surface of a product is high, the product can be formed and processed in a one-step mode, and the method is particularly favorable for aerogel components with large size and large thickness. The supercritical drying is beneficial to further improving the processing quality of the large-size and large-thickness rigid aerogel component, so that the processing quality of the large-size and large-thickness rigid aerogel component is improved. The invention provides a method for forming a large-size and large-thickness rigid aerogel component, the aerogel component processed by the method can exceed 100mm in thickness and 800mm in length and width, the forming die is simple and reliable in design structure and low in die cost, the forming cost of forming a fiber body is reduced, the profile size of an aerogel product can be directly formed in place, the size precision is high, the requirements are met, and the surface is not required to be processed. Through vacuum bag cladding forming die vacuum impregnation, utilize mould structural feature for the sol can be abundant with the impregnation of design corpus fibrosum, need not special vacuum impregnation jar body, product quality is stable, and can process jumbo size, big thickness rigidity aerogel component, and the sol high-usage has reduced the sol cost, and is more favorable to making jumbo size, big thickness rigidity aerogel component.

Drawings

Fig. 1 is a schematic perspective view of a molding die according to the present invention.

Fig. 2 is a schematic view of a split structure of the forming die of the present invention.

FIG. 3 is a schematic perspective view of a convex mold body according to the present invention.

FIG. 4 is a schematic cross-sectional view of the cam body according to the present invention.

FIG. 5 is a second schematic perspective view of the raised mold body of the present invention.

FIG. 6 is a second schematic cross-sectional view of the cam body of the present invention.

FIG. 7 is a schematic perspective view of a concave mold body according to the present invention.

FIG. 8 is a schematic cross-sectional view of a cavity body according to the present invention.

FIG. 9 is a second schematic perspective view of the cavity of the present invention.

FIG. 10 is a second schematic cross-sectional view of the cavity of the present invention.

FIG. 11 is a schematic view showing the structure of a vacuum impregnation apparatus according to the present invention.

FIG. 12 is a schematic view of an assembly structure of a forming mold and a vacuum bag according to the present invention.

FIG. 13 is a schematic cross-sectional view of a vacuum bag according to the present invention.

Detailed Description

The first embodiment is as follows:

as shown in fig. 1, the method for forming a large-size and large-thickness rigid aerogel member according to the present invention comprises the following steps:

(1) preparing: preparing a forming mold 1, a vacuum impregnation device 2, a shaped fiber body 3, a plurality of flexible cotton felts, an autoclave and sol; as shown in fig. 1 to 10, the forming mold 1 includes a male mold body 11, a female mold body 12, two positioning pins 13, and a plurality of locking bolts 14, wherein the male mold body 11 and the female mold body 12 are made of carbon steel or mold steel or stainless steel or aluminum alloy, and the surfaces of the male mold body 11 and the female mold body 12 are galvanized or Cr-plated, a male mold portion 111 is disposed on the lower surface of the male mold body 11, a first annular trimming groove 112 is disposed on the lower surface of the male mold body 11, the first trimming groove 112 surrounds the male mold portion 111, a first guiding groove 113 and a second guiding groove 114 are disposed on the lower surface of the male mold body 11, the first guiding groove 113 and the second guiding groove 114 are disposed on the left side and the right side of the male mold portion 111, the first guiding groove 113 and the second guiding groove 114 extend to the left surface and the right surface of the male mold body 11, respectively, and the first guiding groove 113 and the second guiding groove 114 are communicated with the first trimming groove 112, the upper surface of the convex die body 11 is uniformly provided with a plurality of strip-shaped first glue dipping grooves 115, each first glue dipping groove 115 longitudinally extends, the front end and the rear end of each first glue dipping groove 115 respectively extend to the front surface and the rear surface of the convex die body 11, the width of each first glue dipping groove 115 is 10-20 mm, the depth of each first glue dipping groove 115 is 5-20 mm, the bottom of each first glue dipping groove 115 is uniformly provided with a plurality of first glue dipping holes 116 penetrating to the convex die part 111, each first glue dipping hole 116 in the same first glue dipping groove 115 is arranged side by side along the length direction of the first glue dipping groove 115, the aperture of each first glue dipping hole 116 is 3-6 mm, the distance between two adjacent first glue dipping holes 116 in the same first glue dipping groove 115 is 30-100 mm, the upper surface of the concave die body 12 is provided with a concave die part 121, the upper surface of the concave die body 12 is provided with a second annular trimming groove 122, and the second trimming groove 122 surrounds the cavity part 121, the upper surface of the cavity body 12 is respectively provided with a third guiding groove 123 and a fourth guiding groove 124, the third guiding groove 123 and the fourth guiding groove 124 are respectively positioned at the left side and the right side of the cavity part 121, the third guiding groove 123 and the fourth guiding groove 124 are respectively extended to the left surface and the right surface of the cavity body 12, the third guiding groove 123 and the fourth guiding groove 124 are both communicated with the second trimming groove 122, the lower surface of the cavity body 12 is uniformly provided with a plurality of strip-shaped second glue dipping grooves 125, the second glue dipping grooves 125 are longitudinally extended, the front end and the rear end of each second glue dipping groove 125 are respectively extended to the front surface and the rear surface of the cavity body 12, the width of each second glue dipping groove 125 is 10-20 mm, the depth of each second glue dipping groove 125 is 5-20 mm, the bottom of each second glue dipping groove 125 is uniformly provided with a plurality of second glue dipping holes 126 penetrating through the cavity part 121, arranging the second glue dipping holes 126 in the same second glue dipping groove 125 side by side along the length direction of the second glue dipping groove 125, wherein the aperture of each second glue dipping hole 126 is 3-6 mm, the distance between two adjacent second glue dipping holes 126 in the same second glue dipping groove 125 is 30-100 mm, the male die body 11 is covered on the upper surface of the female die body 12, a forming cavity 100 is formed between the male die part 111 and the female die part 121, the diameter of two positioning pins 13 is 6-20 mm, the two positioning pins 13 are inserted on the male die body 11 side by side, the two positioning pins 13 are respectively positioned at the front side and the rear side of the male die part 111, the two positioning pins 13 are also inserted on the female die body 12, and each locking bolt 14 is locked after penetrating through the male die body 11 and the female die body 12; as shown in fig. 11 to 13, the vacuum impregnation device 2 includes a frame 21, a sol barrel 22, a vacuum pump 23, a vacuum bag 24, a vacuum pump 25, an impregnation tube 26, a vacuum pressure gauge 27, a vacuum valve 28, and an impregnation valve 29, wherein the vacuum bag 24 is provided with a placement cavity 241, the sol barrel 22, the vacuum pump 23, and the vacuum bag 24 are disposed on the frame 21, one end of the vacuum pump 25 is connected to the vacuum pump 23, the other end of the vacuum pump 25 is inserted into the vacuum bag 24, and a nozzle at the other end of the vacuum pump 25 is inserted into an upper portion of the placement cavity 241, the vacuum pressure gauge 27 and the vacuum valve 28 are both connected in series to the vacuum pump 25, and the vacuum pressure gauge 27 is located at an end close to the vacuum pump 23, one end of the impregnation tube 26 is inserted into the sol barrel 22, the other end of the impregnation tube 26 is inserted into the vacuum bag 24, and a nozzle at the other end of the impregnation tube 26, the dipping valve 29 is connected in series with the dipping pipe 26;

(2) placing a shaped fiber body and releasing sol: arranging the shaped fiber body 3 in a forming cavity 100, and adding sol into a sol barrel 22;

(3) packaging and forming die 1: wrapping each corner of the forming mold 1 with a flexible cotton felt, then vertically placing the forming mold 1 in a placing inner cavity 241 of the vacuum bag 24, and further vertically arranging the first glue dipping groove 115;

(4) vacuum impregnation: the vacuum bag 24 is left in a room temperature environment; opening the vacuum valve 28, closing the impregnation valve 29, then starting the vacuum pump 23, and keeping the pressure for at least 5min when the vacuum degree in the placing cavity 241 reaches-0.09 MPa to-0.1 MPa; then the vacuum valve 28 is closed, the dipping valve 29 is opened, and the sol enters the placing inner cavity 241 and the molding cavity 100 along the dipping pipe 26; after the sol is completely impregnated, closing the impregnation valve 29 and allowing the sol to age and gel;

(5) supercritical drying: taking the forming die 1 out of the vacuum bag 24, and then placing the forming die 1 in an autoclave for supercritical drying, wherein ethanol or carbon dioxide is used as a drying medium for supercritical drying;

(6) processing: and (3) disassembling the forming die 1, taking out the formed aerogel component, and trimming to obtain the required aerogel component.

In the method for forming the large-size and large-thickness rigid aerogel member, the convex die body 11 and the concave die body 12 are made of carbon steel or die steel or stainless steel or aluminum alloy, so that the convex die body 11 and the concave die body 12 have high structural strength, and the surfaces of the convex die body 11 and the concave die body 12 are plated with zinc or Cr, so that the rusting of the die can be avoided, and the service life of the die is prolonged. Through the establishment of the first glue dipping groove 115, the first glue dipping hole 116, the second glue dipping groove 125, the second glue dipping hole 126, the first trimming groove 112, the second trimming groove 122, the first diversion groove 113, the second diversion groove 114, the third diversion groove 123 and the fourth diversion groove 124, the stability and the uniformity of the sol entering the molding cavity 100 can be greatly improved, thereby being beneficial to improving the molding stability of the large-size and large-thickness rigid aerogel component, avoiding the conditions of uneven thickness, cracking, poor roughness and the like of the large-size and large-thickness rigid aerogel component, and further greatly improving the molding quality of the large-size and large-thickness rigid aerogel component. Set up through first edging groove 112, second edging groove 122 can not only play the purpose of guide sol, can also make things convenient for the follow-up side to the aerogel component to repair to help improving the processingquality of aerogel component. By vertically placing the forming mold 1 in the placing inner cavity 241 and vertically arranging the first glue dipping tanks 115, all the first glue dipping tanks 115 and all the second glue dipping tanks 125 are vertically arranged, and the notches of the first trimming tank 112 and the second trimming tank 122 on the surface of the forming mold 1 are also arranged side by side right and left or front and back; in addition, the other end pipe orifice of the vacuumizing pipe 25 and the other end pipe orifice of the dipping pipe 26 are arranged up and down, so that the stability of vacuumizing can be ensured, and the sol can be dipped in the forming die 1 from bottom to top when the sol is introduced through the dipping pipe 26; therefore, the sol can more conveniently enter the forming cavity 100 smoothly through the notches formed by the first trimming groove 112 and the second trimming groove 122, the first glue dipping grooves 115, the second glue dipping grooves 125, the first glue dipping holes 116 and the second glue dipping holes 126, the first diversion trench 113, the second diversion trench 114, the third diversion trench 123 and the fourth diversion trench 124, and the shaped fiber body 3 in the forming cavity 100 can be dipped through the sol, so that the dipping stability and the impregnation comprehensiveness can be greatly improved, a large-size and large-thickness rigid aerogel component can be quickly formed, the conditions of uneven thickness, cracking, poor roughness and the like of the aerogel component can be avoided, and the forming quality of the aerogel component can be greatly improved. By wrapping the corners of the forming mold 1 with the flexible cotton felt, the vacuum bag 24 can be prevented from being punctured by the corners of the forming mold 1, so that the air leakage of the vacuum bag 24 can be avoided, which is helpful for improving the reliability of the impregnation. After the dipping valve 29 is opened, the sol to be dipped is siphoned into the molding cavity 100 through vacuum, and the sol is dipped into the shaped fiber body 3 from bottom to top through the holes on the two sides of the molding mold 1, each dipping groove and each dipping hole of the molding mold 1, so that the passage for dipping the sol is greatly increased, the shaped fiber body 3 with large size and large thickness can be effectively and fully dipped, and the processing quality of the rigid aerogel component with large size and large thickness can be improved. The vacuum dipping treatment is carried out by adopting the mode that the vacuum bag 24 is sleeved with the forming die 1, so that special vacuum dipping equipment is not needed in the dipping process, the sol loss is very little, the utilization rate of the sol can be greatly improved, the process is very simple, a special vacuum dipping tank is not needed, the cost is lower, the method is convenient and fast, the forming method has the advantages of simplicity in operation, high processing efficiency, low cost and the like, the size precision of the molded surface of a product is high, the product can be formed and processed in a one-time mode, and the method is particularly favorable for aerogel components with large size and large thickness. The supercritical drying is beneficial to further improving the processing quality of the large-size and large-thickness rigid aerogel component, so that the processing quality of the large-size and large-thickness rigid aerogel component is improved. The invention provides a method for forming a large-size and large-thickness rigid aerogel component, the aerogel component processed by the method can exceed 100mm in thickness and 800mm in length and width, the forming die is simple and reliable in design structure and low in die cost, the forming cost of forming a fiber body is reduced, the profile size of an aerogel product can be directly formed in place, the size precision is high, the requirements are met, and the surface is not required to be processed. Through vacuum bag cladding forming die vacuum impregnation, utilize mould structural feature for the sol can be abundant with the impregnation of design corpus fibrosum, need not special vacuum impregnation jar body, product quality is stable, and can process jumbo size, big thickness rigidity aerogel component, and the sol high-usage has reduced the sol cost, and is more favorable to making jumbo size, big thickness rigidity aerogel component.

Wherein the density of the aerogel component can be 0.07g/cm according to different fiber requirements³～0.45g/cm³This can increase the applicability of the aerogel member.

The diameter of the locking bolt 14 is 9-24 mm, and the aperture ratio of the hole on the male die body 11 and the hole on the female die body 12 for the locking bolt 14 to pass through is larger than 1mm than the diameter of the locking bolt 14.

The carbon steel is Q235R carbon steel or 40 carbon steel. The carbon steel is hardened and tempered steel.

The forming method can conveniently form the special-shaped aerogel component, and has wide application range.

In the vacuum impregnation process, the sol-gel time can be prolonged by adjusting the sol formula and the ambient temperature, and for large-thickness and large-size products, the sol can be favorably permeated into the shaped fiber body 3, so that the processing quality of the large-size and large-thickness rigid aerogel member can be improved. For example, lower temperatures may be used to extend the sol-gel time.

The sol can be a SiO2 sol to enable the fabrication of better rigid aerogel structures.

The inner profiles of the male die part 111 and the female die part 121 are consistent with the surface profile of the aerogel component product; and the peripheries of the male die part 111 and the female die part 121 are flush with the surface of the product, so that the aerogel product can be trimmed when the die is detached.

The vacuum bag 24 is sealed by an adhesive tape or plastic package by a plastic package machine, the vacuum tube 25 and the dip tube 26 are inserted during sealing, the port of the vacuum tube 25 is placed on the upper surface of the forming mold 1, the dip tube 26 is inserted from the upper surface of the vacuum bag 24, the port of the dip tube 26 is placed at the bottom of the forming mold 1, and good sealing and no air leakage are ensured.

And maintaining the pressure for at least 5min, namely maintaining the vacuum degree for at least 5min when the vacuum degree reaches a required value so as to judge whether air leakage exists or not and ensure that the subsequent operation can be smoothly carried out.

The vacuum bag 24 may be replaced with a vacuum membrane.

The shaped fiber body 3 is a fiber felt.

The first glue dipping holes 116 and the second glue dipping holes 126 are 5mm in diameter, the distance between two adjacent first glue dipping holes 116 in the same first glue dipping tank 115 is 50mm, the distance between two adjacent second glue dipping holes 126 in the same second glue dipping tank 125 is 50mm, and the diameter of the positioning pin 13 is 10 mm. The best gum dipping effect can be achieved by adopting the sizes of the aperture of the first gum dipping hole 116, the aperture of the second gum dipping hole 126, the distance between the adjacent first gum dipping holes 116 and the distance between the adjacent second gum dipping holes 126; by using 10mm for the positioning pin 13, it is possible to ensure good structural strength, and thus a very good positioning effect can be obtained.

As shown in fig. 1 to 10, a plurality of abdicating grooves 117 have been provided on the top surface of the die body 11, a plurality of positioning grooves 127 have been provided on the bottom surface of the die body 12, and the positions of the respective positioning grooves 127 and the positions of the respective abdicating grooves 117 are in one-to-one correspondence, the nuts of the respective locking bolts 14 are respectively arranged in the abdicating grooves 117, the nut ends of the respective locking bolts 14 are respectively embedded in the positioning grooves 127, the screws of the respective locking bolts 14 are screwed with the corresponding nuts after passing through the die body 12 and the die body 11, and the front surfaces of the die body 11 and the die body 12 are respectively provided with screw holes 10. Due to the structural design, the end part of the locking bolt 14 can be prevented from protruding out of the surface of the forming die 1, so that vacuum film coating or iron box containing is facilitated, vacuum impregnation is facilitated, and the utilization rate of sol is improved; and the positioning groove 127 may catch the nut end of the locking bolt 14, thereby contributing to an improvement in the reliability of the locking bolt 14. Through seting up of screw hole 10, can supply rings or couple spiro union, just so can make things convenient for the hoist and mount of forming die 1 to help improving the convenience that forming die 1 used.

The top, bottom and front surfaces are the molding dies 1 in a horizontal state.

Example two:

the invention relates to a method for forming a large-size and large-thickness rigid aerogel component,

as shown in FIG. 2, the curved aerogel insulation pack to be prepared takes the following dimensions: the thickness is 40mm, the arc length at one end is 450mm, the arc length at one end is 400mm, the length is 400mm, and the precision of the product profile is required to be +/-0.2 mm; the curved aerogel insulation pack has the same shape as the shaped fibrous body 3 of fig. 2.

Step 1: designing a set of rigid aerogel component forming die for dipping SiO2 sol according to a product drawing;

the die adopts Q235 carbon steel, and the surface of the die is plated with Cr;

the structure of the forming die is completely the same as that of the forming die 1 in the first embodiment, and the forming die also comprises a convex die body 11, a concave die body 12, two positioning pins 13 and a plurality of locking bolts 14;

the aperture of each gum dipping hole is 5 mm; the distance between adjacent glue dipping holes in the same glue dipping tank is 80 mm; the width of each dipping groove is 20mm, and the depth of each dipping groove is 10 mm;

except the matched mold positioning positions of the upper mold and the lower mold, the other parts of the peripheral side surfaces of the forming mold are open, so that the sol can be ensured to fully permeate into the fiber prefabricated member (namely the shaped fiber body 3);

the diameter of the positioning pin is 10 mm;

the locking bolt 14 is M16; the hole diameter of the hole for the locking bolt 14 to penetrate through is 1mm larger than the screw size of the locking bolt 14;

the screw hole on the surface of the mould is provided with the abdicating groove, so that the nut can be clamped in the groove, the height of the screw rod is reduced, the bag is not broken when the subsequent vacuum bag is vacuumized, and the vacuum impregnation is facilitated

The inner molded surfaces of the upper mold and the lower mold of the mold are consistent with the surface molded surface of the aerogel component product; and the periphery of the groove is flush with the surface of the product; the processing precision of the molded surface of the die is +/-0.1 mm;

the vacuum impregnation device is completely the same as the vacuum impregnation device 2 in the first embodiment, and also comprises a frame 21, a sol bucket 22, a vacuum pump 23, a vacuum bag 24, an evacuation pipe 25, an impregnation pipe 26, a vacuum pressure gauge 27, a vacuum valve 28 and an impregnation valve 29, wherein the diameters of the evacuation pipe 25 and the impregnation pipe 26 are 10 mm;

step 2: mould closing and sealing of prefabricated part mould

According to the size of the product, the required fiber prefabricated part is cut according to the volume density and the size (length, width and thickness) of the product, laid on the surface of a mold, and the upper mold and the lower mold are compacted and compounded and fixed; the vacuum bag is adopted for coating, sharp positions such as the edge of the mold and the like are filled and covered by flexible cotton felt and the like before coating, the vacuumizing pipe 25 and the dipping pipe 26 are inserted during sealing, and the vacuumizing pipe 25 is placed on the upper surface of the forming mold; the dip pipe 26 is placed at the bottom of the forming mold, the vacuum bag 24 is sealed by a plastic packaging machine, and the outlet of the vacuum bag 24 is connected with the vacuumizing pipe 25 and is sealed by an adhesive tape at the same time, so that air tightness is ensured;

and step 3: vacuum impregnation

Naturally erecting the sealed forming mold, vacuumizing, keeping the pressure for 5min when the vacuum degree reaches more than-0.09 MPa, ensuring good sealing and no air leakage, closing a vacuum pump valve, opening a glue dipping valve, and carrying out vacuum siphoning on the to-be-dipped sol to a cavity of the forming mold, wherein the sol is dipped in the fiber prefabricated member from the bottom to the top, from openings at two sides, and from a glue dipping channel and a glue dipping hole at the back of the upper mold and the lower mold, so that the channels for dipping the sol are greatly increased, and the large-size and large-thickness prefabricated member can be effectively and fully dipped; and after about 120min of impregnation, closing the vacuumizing valve and the impregnation valve, and aging the gel at the natural temperature.

And 4, step 4: supercritical drying

Taking off a vacuum bag on the forming mold, and placing the forming mold in a high-pressure kettle for supercritical drying by using ethanol as a medium;

and 5: machining

And (4) removing the die of the prepared part after the supercritical drying obtained in the step (4), and trimming to finally obtain the required special-shaped aerogel component.

The sol needed by the dipping in the way has high utilization rate, and the utilization rate of the sol can reach 80 percent; the prefabricated part is net-shaped in size, the cost of fiber raw materials is reduced, the product is large in size, thick in thickness and full in impregnation, no non-soaked area is found after drying, and the molded surface precision of the product meets the requirement through a three-coordinate test.

The invention provides a method for forming a large-size and large-thickness rigid aerogel component, which has the advantages of simple design structure of a die, lower cost of the die, reduction of the shaping cost of a fiber prefabricated component, direct forming of the size of the molded surface of an aerogel product in place, high dimensional precision, satisfaction of requirements and no need of excessive subsequent processing;

vacuum impregnation is carried out through the vacuum bag cladding forming mould, and the structural characteristics of the mould are utilized, so that the sol can be fully impregnated with the fiber prefabricated part, the product quality is stable, the sol utilization rate is high, the sol cost is reduced, and the method is more favorable for large-size and large-thickness rigid aerogel components.

The above embodiments are preferred embodiments of the present invention, and all similar structures and equivalent changes made by the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for forming a large-size and large-thickness rigid aerogel member is characterized by comprising the following steps of:

(1) preparing: preparing a forming mold (1), a vacuum impregnation device (2), a shaped fiber body (3), a plurality of flexible cotton felts, an autoclave and sol; the forming die (1) comprises a convex die body (11), a concave die body (12), two positioning pins (13) and a plurality of locking bolts (14), wherein the convex die body (11) and the concave die body (12) are made of carbon steel or die steel or stainless steel or aluminum alloy, the surfaces of the convex die body (11) and the concave die body (12) are galvanized or Cr-plated, a convex die part (111) is arranged on the lower surface of the convex die body (11), a first annular trimming groove (112) is formed in the lower surface of the convex die body (11), the first trimming groove (112) surrounds the convex die part (111), a first diversion groove (113) and a second diversion groove (114) are respectively formed in the lower surface of the convex die body (11), the first diversion groove (113) and the second diversion groove (114) are respectively positioned at the left side and the right side of the convex die part (111), and the first diversion groove (113) and the second diversion groove (114) respectively extend to the left surface and the right surface of the convex die body (11), and the first guide groove (113) and the second guide groove (114) are communicated with the first trimming groove (112), a plurality of strip-shaped first glue dipping grooves (115) are uniformly formed in the upper surface of the die body (11), each first glue dipping groove (115) extends longitudinally, the front end and the rear end of each first glue dipping groove (115) extend to the front surface and the rear surface of the die body (11), the width of each first glue dipping groove (115) is 10-20 mm, the depth of each first glue dipping groove (115) is 5-20 mm, a plurality of first glue dipping holes (116) penetrating through the male die part (111) are uniformly formed in the bottom of each first glue dipping groove (115), each first glue dipping hole (116) in the same first glue dipping groove (115) is arranged side by side along the length direction of the first glue dipping groove (115), the aperture of each first glue dipping hole (116) is 3-6 mm, and the distance between two adjacent first glue dipping holes (116) in the same first glue dipping groove (115) is 100mm, a concave mould part (121) is arranged on the upper surface of the concave mould body (12), a second annular trimming groove (122) is formed in the upper surface of the concave mould body (12), the second trimming groove (122) surrounds the concave mould part (121), a third guide groove (123) and a fourth guide groove (124) are respectively formed in the upper surface of the concave mould body (12), the third guide groove (123) and the fourth guide groove (124) are respectively positioned on the left side and the right side of the concave mould part (121), the third guide groove (123) and the fourth guide groove (124) are respectively extended to the left surface and the right surface of the concave mould body (12), the third guide groove (123) and the fourth guide groove (124) are communicated with the second trimming groove (122), a plurality of strip-shaped second glue dipping grooves (125) are uniformly formed in the lower surface of the concave mould body (12), and the second glue dipping grooves (125) are longitudinally extended, the front end and the rear end of each second glue dipping groove (125) respectively extend to the front surface and the rear surface of the concave die body (12), the width of each second glue dipping groove (125) is 10-20 mm, the depth of each second glue dipping groove (125) is 5-20 mm, a plurality of second glue dipping holes (126) penetrating to the concave die part (121) are uniformly formed in the bottom of each second glue dipping groove (125), the second glue dipping holes (126) in the same second glue dipping groove (125) are arranged side by side along the length direction of the second glue dipping groove (125), the aperture of each second glue dipping hole (126) is 3-6 mm, the distance between every two adjacent second glue dipping holes (126) in the same second glue dipping groove (125) is 30-100 mm, the convex die body (11) is covered on the upper surface of the concave die body (12), a positioning pin forming cavity (100) is formed between the convex die part (111) and the concave die part (121), and the diameter of the two positioning pins (13) is 6-20 mm, the two positioning pins (13) are inserted in the convex die body (11) side by side, the two positioning pins (13) are respectively positioned at the front side and the rear side of the convex die part (111), the two positioning pins (13) are inserted in the concave die body (12), and each locking bolt (14) penetrates through the convex die body (11) and the concave die body (12) and then is locked; the vacuum impregnation device (2) comprises a rack (21), a sol barrel (22), a vacuum pump (23), a vacuum bag (24), a vacuum-pumping pipe (25), an impregnation pipe (26), a vacuum pressure gauge (27), a vacuum valve (28) and an impregnation valve (29), wherein the vacuum bag (24) is provided with a placing inner cavity (241), the sol barrel (22), the vacuum pump (23) and the vacuum bag (24) are arranged on the rack (21), one end of the vacuum-pumping pipe (25) is connected onto the vacuum pump (23), the other end of the vacuum-pumping pipe (25) is arranged in the vacuum bag (24) in a penetrating manner, the pipe orifice of the other end of the vacuum-pumping pipe (25) is arranged on the upper part of the placing inner cavity (241) in a penetrating manner, the vacuum pressure gauge (27) and the vacuum valve (28) are both connected on the vacuum-pumping pipe (25) in series, and the vacuum pressure gauge (, one end of the dip pipe (26) is arranged in the sol barrel (22) in a penetrating manner, the other end of the dip pipe (26) is arranged in the vacuum bag (24) in a penetrating manner, the pipe orifice at the other end of the dip pipe (26) is arranged at the lower part of the placing inner cavity (241) in a penetrating manner, and the dip valve (29) is connected to the dip pipe (26) in series;

(2) placing a shaped fiber body and releasing sol: arranging the shaped fiber body (3) in a forming cavity (100), and adding sol into a sol barrel (22);

(3) packaging and forming die (1): wrapping each corner of the forming mould (1) by using a flexible cotton felt, then vertically placing the forming mould (1) in a placing inner cavity (241) of a vacuum bag (24), and enabling a first glue dipping groove (115) to be vertically arranged;

(4) vacuum impregnation: -subjecting the vacuum bag (24) to an ambient temperature environment; opening a vacuum valve (28), closing a dipping valve (29), then opening a vacuum pump (23), and keeping the pressure for at least 5min when the vacuum degree in the placing inner cavity (241) reaches-0.09 to-0.1 MPa; then closing the vacuum valve (28) and opening the dipping valve (29), so that the sol enters the placing inner cavity (241) and the molding cavity (100) along the dipping pipe (26); after the sol is completely impregnated, closing an impregnation valve (29) and allowing the sol to age and gel;

(5) supercritical drying: taking the forming die (1) out of the vacuum bag (24), and then placing the forming die (1) in an autoclave for supercritical drying, wherein ethanol or carbon dioxide is used as a drying medium for supercritical drying;

(6) processing: and (3) disassembling the forming mold (1), taking out the formed aerogel component, and trimming to obtain the required aerogel component.

2. A method of forming a large-size, large-thickness rigid aerogel structure, as claimed in claim 1, wherein: the aperture of the first glue dipping holes (116) and the aperture of the second glue dipping holes (126) are 5mm, the distance between two adjacent first glue dipping holes (116) in the same first glue dipping tank (115) is 50mm, the distance between two adjacent second glue dipping holes (126) in the same second glue dipping tank (125) is 50mm, and the diameter of the positioning pin (13) is 10 mm.

3. A method of forming a large-size, large-thickness rigid aerogel structure, as claimed in claim 1, wherein: seted up a plurality of grooves of stepping down (117) on the top surface of die body (11), a plurality of constant head tank (127) have been seted up on the bottom surface of die body (12) to make the position of each constant head tank (127) and the position one-to-one of each groove of stepping down (117), the nut of each locking bolt (14) is arranged respectively in the groove of stepping down (117), and the nut end of each locking bolt (14) inlays respectively in constant head tank (127), and the screw rod of each locking bolt (14) passes behind die body (12), die body (11) and the nut looks spiro union that corresponds, be equipped with screw hole (10) on the front surface of die body (11) and die body (12) respectively.

4. A large size, large thickness rigid aerogel structure, characterized by: is obtained by the molding method according to any of claims 1 to 3.

5. An aerogel structure according to claim 4, wherein: the thickness dimension of the aerogel component can exceed 100mm, and the length and width dimensions can exceed 800 mm.