Preparation method of high-temperature-resistant light-weight heat-insulating silica gel plate

Abstract

The application discloses a preparation method of a high-temperature-resistant light heat-insulating silica gel plate, and comprises silicone rubber, a curing agent, a diluent and heat-insulating fillers, and is characterized by comprising the following steps: S1, preparing premix, adding the silicone rubber and the curing agent in a container, uniformly stirring, then adding the diluent, stirring until the color and viscosity are uniform, and then adding the heat-insulating fillers and fully stirring until the color is uniform; S2, laying up, placing a mold on a silica gel plate preparation production line, uniformly laying up the prepared premix in the mold, and compacting the mold edge with hands; and S3, pre-pressing, laying up a cut polytetrafluoroethylene release cloth in the mold, closing the mold, and pre-pressing for 3-5 times by knocking the silica gel plate preparation production line. The mold opening mechanism, the pre-pressing mechanism and the limiting mechanism can achieve the effects of automatic mold opening, mold closing and automatic pre-pressing, and can stably clamp the mold while precisely pre-pressing and opening the mold.

Description

Technical Field

[0001] This invention relates to the field of silicone sheet technology, specifically to a method for preparing a high-temperature resistant, lightweight, heat-insulating silicone sheet. Background Technology

[0002] With the upgrading of weapons and equipment, the speed of flying chess is getting faster and faster, which puts higher demands on the temperature resistance of adhesives and sealants. When the flight speed is greater than Mach 3, the surface temperature of missiles, aircraft and other aircraft will be greater than 300°C. The original heat insulation felt products have complicated molding processes, are difficult to bond and have insufficient rigidity. Ordinary silicone heat insulation boards generally have a temperature resistance of less than 300°C, insufficient heat insulation effect and high weight, which cannot meet the needs of current weapons and equipment.

[0003] Currently, thermal insulation silicone sheets used in aircraft are typically formed by stamping with molds. However, since the raw material of silicone sheets is in the form of mud, it is difficult to ensure equal material feeding during the feeding process in the mold. Pre-pressing and other processing are usually required to ensure the flatness of the silicone sheet. At present, the pre-pressing and feeding of silicone sheets can only be done manually. There is a lack of a production line specifically for silicone sheet preparation. The feeding process requires frequent mold opening and closing, which is time-consuming and labor-intensive, resulting in low production efficiency of silicone sheets. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a high-temperature resistant, lightweight, heat-insulating silicone sheet, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a high-temperature resistant lightweight heat-insulating silicone rubber sheet, comprising silicone rubber, a curing agent, a diluent, and a heat-insulating filler, wherein the steps of the method for preparing the silicone rubber sheet are as follows: S1: To prepare the premix, add silicone rubber and curing agent to a container and stir evenly. Then add diluent and stir until the color and viscosity are uniform. Then add heat insulation filler and stir thoroughly until the color is uniform. S2: Material spreading: Place the mold on the silicone plate preparation production line, spread the prepared premixed material evenly in the mold, and press the mold edges firmly by hand; S3: Pre-compression. The cut polytetrafluoroethylene release cloth is laid on the premixed material in the mold. The mold is closed and the silicone plate production line taps it 3 to 5 times to perform pre-compression. S4: Replenish material, open the mold and remove the PTFE release cloth, and evenly fill the missing material position with the reserved premixed material; S5: Mold closing, the mold is closed to complete the mold closing process; S6: Pressing. Place the mold in the silicone sheet preparation production line, adjust the pressing pressure to 0.3MPa~1MPa, then release the pressure. Repeat the above pressing and releasing process three times. Finally, press the mold to close and hold the pressure. The holding pressure is 9.0MPa~11MPa, and the holding time is 1min~2min. After pressing, remove the mold, tighten it with fastening bolts, and use a 0.1mm thick feeler gauge to check the gap between the mold flanges to ensure that the 0.1mm thick feeler gauge cannot be inserted. S7: Curing. Place the mold in an oven at 80±5℃ for 23h~24h, and finally remove it from the oven and let it cool naturally to room temperature. S8: Demolding, disassemble the mold, remove the product from the mold to obtain the molded silicone block; S9: Post-processing: Place multiple silicone blocks on a tray and put them in an oven at 100±5℃ for 23h~24h.

[0006] Preferably, the mass ratio of silicone rubber, curing agent, diluent and heat insulation filler in S1 is 10:2:7:10.

[0007] Preferably, the mold includes a female mold, and a male mold is disposed above the female mold. Fixing rods are disposed on both side walls of the female mold and the male mold. The number of fixing rods is eight, and they are arranged symmetrically in pairs on both side walls of the female mold and the male mold. The silicone sheet preparation production line includes a frame. A conveying mechanism is installed on the upper surface of the frame. A mold opening mechanism is installed on the upper surface of the middle part of the frame. A pre-pressing mechanism is installed on the upper surface of the frame on one side of the mold opening mechanism. A press is disposed on the side of the frame near the pre-pressing mechanism. Preferably, the conveying mechanism includes a conveying frame, with rollers embedded in the upper surface of the conveying frame, and sliding grooves extending through the side walls of the conveying frame. A slot is provided above the end of the sliding groove away from the press, and a limit mechanism is installed on both side walls of the conveying frame.

[0008] Preferably, the limiting mechanism includes a limiting block, the limiting block is hook-shaped, a limiting groove is formed on one side of the top of the limiting block, a rotating shaft is provided through the bottom of the limiting block, one end of the rotating shaft is connected to a motor, and the number of limiting mechanisms is several, two in a group are symmetrically arranged on both sides of the two fixing rods on the side wall of the female mold.

[0009] Preferably, the limiting groove is semi-circular, the inner diameter of the limiting groove is adapted to the outer diameter of the fixing rod, the limiting block is engaged with the fixing rod through the limiting groove, one end of the rotating shaft passes through the limiting block and is connected to the motor shaft end, and the other end of the rotating shaft is rotatably connected to the conveyor frame through a bearing.

[0010] Preferably, the mold opening mechanism includes a mold opening bracket, with rodless cylinders installed on both inner walls of the mold opening bracket. A mounting base is installed on each rodless cylinder, and a mold opening template is connected to the bottom of the mounting base. U-shaped blocks are provided at both ends of the mold opening template, with U-shaped grooves formed inside each U-shaped block. A through groove is formed on the inner wall of the U-shaped groove near the center of the mold opening template, and an insert is provided inside the through groove. A retaining groove is formed on the inner wall of the U-shaped groove away from the through groove. A telescopic cylinder is connected to the side of the insert near the center of the mold opening template, and the mold opening template is mounted on the rodless cylinder via the mounting base.

[0011] Preferably, the U-shaped block is integrally connected with the template, the inner wall width of the U-shaped groove is adapted to the outer diameter of the fixing rod, the U-shaped groove is movably inserted into the fixing rod, and the spacing between the two U-shaped grooves on the template corresponds to the spacing between the fixing rods on the template.

[0012] Preferably, the width of the insert block is adapted to the width of the inner wall of the through groove, the insert block and the inner wall of the through groove form a sliding connection, the insert block is connected to the telescopic end of the telescopic cylinder, and the insert block is inserted through the U-shaped groove and the slot.

[0013] Preferably, the pre-compression mechanism includes a pre-compression bracket, a movable plate connected to the middle of the pre-compression bracket, a counterweight connected to the bottom of the movable plate away from the pre-compression bracket, a first pin penetrating between the movable plate and the pre-compression bracket, a fixed frame installed in the middle of the side wall of the pre-compression bracket, an electric telescopic rod connected to the top of the fixed frame, a second pin penetrating between one end of the electric telescopic rod and the fixed frame, and a movable ring connected to the center of the upper surface of the movable plate at the other end of the electric telescopic rod.

[0014] Preferably, the pre-compression bracket is installed on the upper surface of the frame, the movable plate is rectangular, one end of the movable plate is rotatably connected to the pre-compression bracket via a first pin, the counterweight corresponds to the middle position of the conveyor frame, one end of the electric telescopic rod is rotatably connected to the fixed frame via a second pin, and the telescopic end of the electric telescopic rod is movably connected to the center of the upper surface of the movable plate via a movable ring.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The preparation method of this high-temperature resistant lightweight heat-insulating silicone sheet involves setting up a mold opening mechanism. When the mold moves to the bottom of the mold opening mechanism, the rodless cylinder drives the mold opening plate to move down through the mounting base, so that the fixing rods on both sides of the male mold are inserted into the U-shaped groove of the mold opening plate. The telescopic cylinder is driven to extend, and the telescopic cylinder pushes the insert block to slide in the through groove, so that the insert block passes through the U-shaped block and is inserted into the slot. At this time, the top of the insert block contacts the bottom of the fixing rod. Through the blocking of the insert block, after the rodless cylinder drives the mold opening plate to move up, the mold opening plate pulls the male mold up, so that the male mold and the female mold are separated. After the mold is replenished, the rodless cylinder drives the male mold to move down, thus achieving the effect of automatic mold opening and closing.

[0016] 2. The preparation method of this high-temperature resistant lightweight heat-insulating silicone sheet involves setting up a pre-compression mechanism. When the mold moves to the bottom of the pre-compression mechanism, the electric telescopic rod extends and pushes the movable plate to rotate around the first pin shaft. The movable plate rotates downward and drives the counterweight to strike the center of the mold on the conveyor frame. The counterweight strikes and compresses the raw material to fit the mold, and vibrates the raw material in the mold to make it spread evenly, thus achieving the effect of automatic pre-compression of the raw material in the mold.

[0017] 3. The preparation method of this high-temperature resistant lightweight heat-insulating silicone sheet involves setting a limiting mechanism. During the movement of the mold on the conveying mechanism, the motor drives the rotating shaft to rotate, which in turn drives the limiting block to rotate, so that the limiting block rotates to a vertical position. The vertical limiting block prevents the fixed rod sliding in the groove from moving out of place. At the same time, the fixed rod is locked into the slot. The two limiting blocks are symmetrically set to clamp and position the two fixed rods, which not only assists the mold in precise pre-pressing and mold opening, but also stably clamps the mold.

[0018] 4. The preparation method of this high-temperature resistant lightweight heat-insulating silicone sheet involves setting up a conveying mechanism. During the movement of the mold on the conveying frame, the mold is supported by the rolling of rollers. At this time, the horizontal movement of the mold is restricted by the inner walls on both sides of the conveying frame. The fixing rods on both sides of the mold are inserted into the slide groove, and the longitudinal movement of the fixing rods is restricted by the inner wall of the slide groove. On the one hand, this standardizes the production movement path of the mold and ensures that the raw materials are accurately processed on the silicone sheet preparation production line. On the other hand, the limiting effect of the slide groove on the fixing rods cooperates with the mold opening mechanism to smoothly drive the mold to open automatically. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the silicone plate preparation production line of the present invention; Figure 2 This is a schematic diagram of the overall structure of the mold of the present invention; Figure 3 This is a schematic diagram of the conveyor frame structure of the present invention; Figure 4 This is a schematic diagram of the limiting mechanism structure of the present invention; Figure 5This is a schematic diagram of the mold opening mechanism of the present invention; Figure 6 This is a schematic diagram of the top structure of the template of the present invention; Figure 7 This is a schematic diagram of the bottom structure of the template of the present invention; Figure 8 This is a schematic diagram of the pre-compression mechanism of the present invention.

[0020] In the diagram: 1. Silicone sheet preparation production line; 2. Frame; 3. Conveying mechanism; 31. Conveying frame; 32. Roller; 33. Slide groove; 34. Slot; 35. Limiting mechanism; 351. Limiting block; 352. Limiting groove; 353. Rotating shaft; 354. Motor; 4. Mold opening mechanism; 41. Mold opening bracket; 42. Rodless cylinder; 43. Mounting base; 44. Mold opening template; 45. U-shaped block; 46. U-shaped groove; 47. Through groove; 48. Insert block; 49. Slot; 410. Telescopic cylinder; 5. Pre-compression mechanism; 51. Pre-compression bracket; 52. Movable plate; 53. Counterweight; 54. First pin; 55. Fixed frame; 56. Electric telescopic rod; 57. Second pin; 58. Movable ring; 6. Press; 7. Female mold; 71. Male mold; 72. Fixed rod. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Example 1 like Figures 1 to 8 As shown in this embodiment, the preparation method of the high-temperature resistant lightweight heat-insulating silicone sheet includes silicone rubber, curing agent, diluent and heat-insulating filler, and the materials used are as follows: Silicone rubber base: 201 silicone rubber (Zhengzhou Cehong Rubber Products Co., Ltd., brand name CHSR201) Curing agent: CL silane coupling agent (KH-CL, Institute of Chemistry, Chinese Academy of Sciences) Diluent: Cyclohexane Thermal insulation filler: hollow glass microspheres (3M K1, USA); The steps for preparing the silicone sheet are as follows: S1: Prepare the premix. Add silicone rubber and curing agent to a container and stir evenly. Then add diluent and stir until the color and viscosity are uniform. Then add heat insulation filler and stir thoroughly until the color is uniform. In addition, before preparing the premix, the mold needs to be cleaned. Remove the residue on the mold surface and the parting surface with thin phenolic board and copper sheet respectively. Then wipe the inner cavity, edge strip and working surface of the mold with cotton yarn soaked in gasoline. After the gasoline evaporates, wipe it 1-2 times with cotton yarn soaked in acetone. Then assemble the male and female molds 71 ​​into place and lay the release cloth on the male mold 71. Draw lines on the release cloth according to the edge of the male mold 71, and then cut the polytetrafluoroethylene release cloth along the drawn lines. S2: Spreading material: Place the mold on the silicone plate preparation production line 1, spread the prepared premixed material evenly in the mold, press the edge strip of the mold firmly by hand, and finally reserve 20g~30g of premixed material for replenishment. S3: Pre-compression. The cut polytetrafluoroethylene release cloth is laid on the premixed material in the mold. The mold is closed and the silicone plate preparation production line 1 taps it 3 to 5 times to perform pre-compression. S4: Replenish material, open the mold and remove the PTFE release cloth, and evenly fill the missing material position with the reserved premixed material; S5: Mold closing, the mold is closed to complete the mold closing process; S6: Pressing. Place the mold in the silicone sheet preparation production line 1, adjust the pressing pressure to 0.3MPa~1MPa, then release the pressure. Repeat the above pressing and releasing process three times. Finally, squeeze the mold to close and hold the pressure. The holding pressure is 9.0MPa~11MPa, and the holding time is 1min~2min. After pressing, take out the mold, tighten it with fastening bolts, and use a 0.1mm thick feeler gauge to check the gap between the mold flanges to ensure that the 0.1mm thick feeler gauge cannot be inserted. S7: Curing. Place the mold in an oven at 80±5℃ for 23h~24h, and finally remove it from the oven and let it cool naturally to room temperature. S8: Demolding, disassemble the mold, remove the product from the mold to obtain the molded silicone block; S9: Post-processing: Place multiple silicone blocks on a tray and put them in an oven at 100±5℃ for 23h~24h.

[0025] Specifically, the mass ratio of silicone rubber, curing agent, diluent and heat insulation filler in S1 is 10:2:7:10. The performance of the silicone sheet obtained according to this ratio reaches the optimal value.

[0026] Furthermore, the mold includes a female mold 7, and a male mold 71 is provided above the female mold 7. Fixing rods 72 are provided on both sides of the female mold 7 and the male mold 71. There are eight fixing rods 72, arranged symmetrically in pairs on both sides of the female mold 7 and the male mold 71. There are two fixing rods 72 on each side of the female mold 7 and the male mold 71. The silicone sheet preparation production line 1 includes a frame 2. A conveying mechanism 3 is installed on the upper surface of the frame 2. The conveying mechanism 3 is used for guiding the mold movement. A mold opening mechanism 4 is installed on the upper surface of the middle part of the frame 2. It is used for automatically opening and closing the mold. A pre-pressing mechanism 5 is installed on the upper surface of the frame 2 on one side of the mold opening mechanism 4. It is used for rotating and pre-pressing the mold. A press 6 is provided on the side of the frame 2 near the pre-pressing mechanism 5. The press 6 is a device for pressing the raw material in the mold. The conveying mechanism 3 and the pressing surface of the press 6 are flush, which facilitates the movement of the mold on the conveying mechanism 3 to the press 6. The conveying mechanism 3 includes a conveying frame 31, which is fixed to the upper surface of the frame 2. Rollers 32 are embedded in the upper surface of the conveying frame 31 and are in a rolling connection with the conveying frame 31 to reduce the friction between the bottom of the mold and the surface of the conveying frame 31, making the mold move more smoothly. Slide grooves 33 are provided through the side walls of the conveying frame 31. A slot 34 is provided above the end of the slide groove 33 away from the press 6. There are two slots 34. The distance between the two slots 34 corresponds to the distance between the two fixing rods 72 on the same side wall of the mold. By passing the fixing rods 72 through the slots 34, the fixing rods 72 can be inserted into the slide grooves 33. When the mold moves on the conveying frame 31, the fixing rods 72 also slide in the slide grooves 33. Limiting mechanisms 35 are installed on both side walls of the conveying frame 31.

[0027] Furthermore, the limiting mechanism 35 includes a limiting block 351, which is hook-shaped. A limiting groove 352 is provided on one side of the top of the limiting block 351. A rotating shaft 353 is provided through the bottom of the limiting block 351. One end of the rotating shaft 353 is connected to a motor 354. The motor 354 is essentially an electric motor with forward and reverse rotation circuits. The shaft end of the motor 354 is connected to the rotating shaft 353. The motor 354 is installed on the side wall of the conveyor frame 31. There are several limiting mechanisms 35, which are arranged symmetrically in pairs on both sides of the two fixing rods 72 on the side wall of the female mold 7. The limiting mechanism 35 is used for mold movement and positioning on the conveyor frame 31.

[0028] Furthermore, the limiting groove 352 is semi-circular, and its inner diameter is matched with the outer diameter of the fixed rod 72. The limiting block 351 is engaged with the fixed rod 72 through the limiting groove 352. The vertical limiting block 351 prevents the fixed rod 72 from moving out of its position while sliding in the slide groove 33. At the same time, the fixed rod 72 is engaged in the slot 34. The two limiting blocks 351 are symmetrically arranged to clamp and position the two fixed rods 72. This helps to accurately pre-press and open the mold while stably clamping the mold. One end of the rotating shaft 353 passes through the limiting block 351 and is connected to the shaft end of the motor 354. The other end of the rotating shaft 353 is rotatably connected to the conveyor frame 31 via a bearing. The motor 354 drives the rotating shaft 353 to rotate, which in turn drives the limiting block 351 to rotate, so that the limiting block 351 rotates to a vertical position to prevent the fixed rod 72 from moving in the slide groove 33.

[0029] Furthermore, the mold opening mechanism 4 includes a mold opening bracket 41, which is U-shaped and fixed to the upper surface of the frame 2. Rodless cylinders 42 are installed on the inner walls of both sides of the mold opening bracket 41. The two rodless cylinders 42 are connected to the same air source and driven synchronously. A mounting base 43 is installed on each rodless cylinder 42. The mounting base 43 is a right-angled plate with a 90° bend in the middle. The mounting base 43 connects the rodless cylinder 42 to the mold opening template 44. The bottom of the mounting base 43 is connected to the mold opening template 44. U-shaped blocks 45 are provided at both ends of the mold opening template 44. U-shaped grooves 46 are formed inside the U-shaped blocks 45, which are close to the mold opening template. A through groove 47 is provided through one side of the inner wall of the middle section of the template 44. An insert block 48 is provided through the through groove 47. The insert block 48 slides and extends within the through groove 47. A slot 49 is provided on the inner wall of the U-shaped groove 46 away from the through groove 47. A telescopic cylinder 410 is connected to the side of the insert block 48 near the middle of the template 44. The telescopic cylinder 410 is installed at the bottom of the template 44. There are also two telescopic cylinders 410 corresponding to the two U-shaped blocks 45. The two telescopic cylinders 410 are connected to the same air source and driven synchronously. The template 44 is installed on the rodless cylinder 42 via the mounting base 43. The template 44 is driven to rise and fall by the rodless cylinder 42.

[0030] Furthermore, the U-shaped block 45 is integrally connected with the mold opening template 44, the inner wall width of the U-shaped groove 46 is adapted to the outer diameter of the fixing rod 72, the U-shaped groove 46 and the fixing rod 72 are movably inserted, and the distance between the two U-shaped grooves 46 on the mold opening template 44 corresponds to the distance between the fixing rods 72 on the template. When the mold moves to the bottom of the mold opening mechanism 4, the mold opening template 44 is driven to move down through the mounting base 43 by the rodless cylinder 42, so that the fixing rods 72 on both sides of the male mold 71 are inserted into the U-shaped grooves 46 of the mold opening template 44.

[0031] Furthermore, the width of the insert block 48 is adapted to the width of the inner wall of the through groove 47, and the insert block 48 and the inner wall of the through groove 47 form a sliding connection. The insert block 48 is connected to the telescopic end of the telescopic cylinder 410. The insert block 48 passes through the U-shaped groove 46 and is inserted into the slot 49. By extending the telescopic cylinder 410, the telescopic cylinder 410 pushes the insert block 48 to slide in the through groove 47, so that the insert block 48 passes through the U-shaped block 45 and is inserted into the slot 49. At this time, the top of the insert block 48 contacts the bottom of the fixed rod 72. After the rodless cylinder 42 drives the opening template 44 to move upward, the opening template 44 pulls the male mold 71 upward, so that the male mold 71 separates from the female mold 7.

[0032] Furthermore, the pre-compression mechanism 5 includes a pre-compression bracket 51, which is fixed to the upper surface of the frame 2. A movable plate 52 is connected to the middle of the pre-compression bracket 51. A counterweight block 53 is connected to the bottom of the movable plate 52 away from the pre-compression bracket 51. A first pin 54 is provided through the movable plate 52 and the pre-compression bracket 51. A fixed frame 55 is installed in the middle of the side wall of the pre-compression bracket 51. The fixed frame 55 is used to install an electric telescopic rod 56. An electric telescopic rod 56 is connected to the top of the fixed frame 55. The electric telescopic rod 56 is used to drive the movable plate 52 to move. A second pin 57 is provided through the electric telescopic rod 56 to the fixed frame 55. A movable ring 58 is connected to the center of the upper surface of the movable plate 52 at the other end of the electric telescopic rod 56.

[0033] Furthermore, the pre-compression bracket 51 is installed on the upper surface of the frame 2, and the movable plate 52 is rectangular. One end of the movable plate 52 is rotatably connected to the pre-compression bracket 51 via the first pin 54. The counterweight 53 is positioned in the middle of the conveyor frame. The movable plate 52 rotates downward, causing the counterweight 53 to strike the center of the mold on the conveyor frame 31. The counterweight 53 strikes and compresses the raw material to fit the mold, and vibrates the raw material in the mold to make it spread evenly, thus achieving the effect of automatic pre-compression of the raw material in the mold. One end of the electric telescopic rod 56 is rotatably connected to the fixed frame 55 via the second pin 57. The telescopic end of the electric telescopic rod 56 is movably connected to the center of the upper surface of the movable plate 52 via the movable ring 58. When the electric telescopic rod 56 extends, it pushes the movable plate 52 to rotate around the first pin 54. At this time, the electric telescopic rod 56 itself rotates relative to the fixed frame 55 and the movable plate 52.

[0034] The usage method of this embodiment is as follows: When the user actually uses the silicone sheet preparation production line 1 to produce high-temperature resistant lightweight heat-insulating silicone sheets, firstly, the cleaned female mold 7 is placed on the conveyor frame 31, and the fixing rods 72 on both sides of the female mold 7 are inserted into the slide groove 33 from the slot 34. Then, the pre-mixed raw material is spread in the mold, and the edges of the female mold 7 are pressed firmly by hand, leaving 20g to 30g of premixed material for replenishment. Then, the cut polytetrafluoroethylene release cloth is laid on the premixed material of the female mold 7, and the male mold 71 is closed on top of the female mold 7. At the same time, the motor 354 at the corresponding position of the pre-pressing mechanism 5 is started, and the motor 354 drives... The rotating shaft 353 rotates, causing the limiting block 351 to rotate, so that the limiting block 351 near the press 6 rotates to a vertical position. Then, it pushes the mold to move it below the pre-pressing mechanism 5. The fixed rod 72 slides in the slide groove 33. The vertical limiting block 351 prevents the fixed rod 72 from moving out of place in the slide groove 33. Then, another limiting block 351 in the same group rotates, so that the two fixed rods 72 on the same side of the mold are respectively inserted into the two symmetrical slots 34. The limiting block 351 clamps and positions the two fixed rods 72. Then, pre-pressing begins. The electric telescopic rod 56 extends and pushes the movable plate. 52 rotates around the first pin 54, causing the movable plate 52 to rotate downwards, driving the counterweight 53 to strike the center of the mold on the conveyor frame 31. The counterweight 53 is controlled to strike the extrusion mold 3 to 5 times. After pre-pressing, the mold is pulled to move below the mold opening mechanism 4 and positioned in conjunction with the corresponding limiting mechanism 35 of the mold opening mechanism 4. The rodless cylinder 42 drives the mold opening template 44 to move downwards via the mounting base 43, so that the fixing rods 72 on both sides of the male mold 71 are inserted into the U-shaped grooves 46 of the mold opening template 44. The telescopic cylinder 410 is driven to extend, and the telescopic cylinder 410 pushes the insert block 48 to slide in the through groove 47, so that the insert block 48 passes through the U-shaped block 45 and inserts into the card. Inside the groove 49, the top of the insert block 48 is in contact with the bottom of the fixing rod 72. Blocked by the insert block 48, after the rodless cylinder 42 drives the opening template 44 to move upward, the opening template 44 pulls the male mold 71 upward, so that the male mold 71 is separated from the female mold 7. Then the mold is pulled out and the PTFE release cloth is removed. The reserved premixed material is evenly filled into the missing material position. After the material is replenished, it is pushed back below the mold opening mechanism 4. The rodless cylinder 42 drives the male mold 71 to move downward and squeezes the female mold 7 and the male mold 71 to close the mold. After the mold is closed, the mold is pushed to the press 6 for pressing. After pressing, it is taken off from the silicone plate preparation production line 1 and transferred for batch drying and curing.

[0035] Example 2 The materials used for silicone rubber, curing agent, diluent, and thermal insulation filler are as follows: Silicone rubber base: 747 silicone rubber (Tianshan Kesai New Materials Co., Ltd., grade TS747) Hardener: 550 Hardener (Nanjing Chenggong KH-550) Diluent: Cyclohexane Thermal insulation filler: Aerogel powder (Henan Fanrui Yihui).

[0036] Example 3 The materials used for silicone rubber, curing agent, diluent, and thermal insulation filler are as follows: Silicone rubber base: Silicone rubber (Nanjing University grade ND312) Curing agent: 1100 vulcanizing agent (Dow Chemical A-1100) Diluent: Cyclohexane Thermal insulation filler: hollow glass microspheres (3MK1, USA).

[0037] Example 4 The materials used for silicone rubber, curing agent, diluent, and thermal insulation filler are as follows: Silicone rubber base: 201 silicone rubber (Zhengzhou Cehong Rubber Products Co., Ltd., brand name CHSR201) Curing agent: CL silane coupling agent (KH-CL, Institute of Chemistry, Chinese Academy of Sciences) Diluent: Cyclohexane Thermal insulation filler: hollow glass microspheres (Zhongke Yali H20).

[0038] The final properties of the silicone sheets prepared in the four examples are shown in the table below:

[0039] Thermal conductivity is an indicator that directly reflects the thermal insulation performance of a material. Generally speaking, the higher the thermal conductivity, the stronger the thermal conductivity and the worse the thermal insulation performance. As shown in the table above, the silicone sheets produced in Example 1 and Example 3 have good thermal insulation performance. The silicone sheet produced in Example 1 only lost 0.8% of its weight at 350°C. Therefore, it can be concluded that the raw material used in Example 1 has the best high-temperature resistance and thermal insulation performance.

[0040] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-temperature resistant, lightweight, heat-insulating silicone rubber sheet, comprising silicone rubber, a curing agent, a diluent, and a heat-insulating filler, characterized in that... The steps for preparing the silicone sheet are as follows: S1: To prepare the premix, add silicone rubber and curing agent to a container and stir evenly. Then add diluent and stir until the color and viscosity are uniform. Then add heat insulation filler and stir thoroughly until the color is uniform. S2: Spreading material, place the mold on the silicone plate preparation production line (1), spread the prepared premixed material evenly in the mold, and press the mold edge strip with your hand; S3: Pre-pressing, place the cut polytetrafluoroethylene release cloth on the premixed material in the mold, close the mold, and pre-press by striking 3 to 5 times by the silicone plate preparation production line (1); S4: Replenish material, open the mold and remove the PTFE release cloth, and evenly fill the missing material position with the reserved premixed material; S5: Mold closing, the mold is closed to complete the mold closing process; S6: Pressing, place the mold in the silicone sheet preparation production line (1), adjust the pressing pressure value to 0.3MPa~1MPa, then release the pressure, repeat the above pressing and releasing process three times, finally squeeze the mold to close the mold and hold the pressure, the holding pressure value is 9.0MPa~11MPa, the holding time lasts 1min~2min, after pressing, take out the mold, lock it with fastening bolts, and use a 0.1mm thick feeler gauge to check the gap between the mold flange surfaces to ensure that the 0.1mm thick feeler gauge cannot be inserted; S7: Curing. Place the mold in an oven at 80±5℃ for 23h~24h, and finally remove it from the oven and let it cool naturally to room temperature. S8: Demolding, disassemble the mold, remove the product from the mold to obtain the molded silicone block; S9: Post-processing: Place multiple silicone blocks on a tray and put them in an oven at 100±5℃ for 23h~24h. The mold includes a female mold (7), and a male mold (71) is provided above the female mold (7). Fixing rods (72) are provided on both sides of the female mold (7) and the male mold (71). There are eight fixing rods (72), which are arranged symmetrically in pairs on both sides of the female mold (7) and the male mold (71). The silicone sheet preparation production line (1) includes a frame (2). A conveying mechanism (3) is installed on the upper surface of the frame (2). A mold opening mechanism (4) is installed on the upper surface of the middle part of the frame (2). The mold opening mechanism (4) includes a mold opening bracket (41). A rodless cylinder (42) is installed on both inner walls of the mold opening bracket (41). A mounting seat (43) is installed on the rodless cylinder (42). A mold opening template (44) is connected to the bottom of the mounting seat (43). A U-shaped block (45) is provided at both ends of the mold opening template (44). A U-shaped groove (46) is provided inside the U-shaped block (45). A through groove (47) is provided through the inner wall of the U-shaped groove (46) near the middle of the mold opening template (44). An insert (48) is provided through the through groove (47). A slot (49) is provided on the inner wall of the U-shaped groove (46) away from the through groove (47). A telescopic cylinder (410) is connected to the side of the insert (48) near the middle of the mold opening template (44). The mold opening template (44) is installed on the rodless cylinder (42) via the mounting seat (43). The U-shaped block (45) is integrally connected with the template (44), the inner wall width of the U-shaped groove (46) is adapted to the outer diameter of the fixing rod (72), the U-shaped groove (46) and the fixing rod (72) are movably inserted, and the distance between the two U-shaped grooves (46) on the template (44) corresponds to the distance between the fixing rods (72) on the template; The width of the insert (48) is adapted to the width of the inner wall of the through groove (47). The insert (48) and the inner wall of the through groove (47) form a sliding connection. The insert (48) is connected to the telescopic end of the telescopic cylinder (410). The insert (48) is inserted through the U-shaped groove (46) and the slot (49).

2. The method for preparing the high-temperature resistant lightweight heat-insulating silicone sheet according to claim 1, characterized in that: The mass ratio of silicone rubber, curing agent, diluent and heat insulation filler in S1 is 10:2:7:

10.

3. The method for preparing the high-temperature resistant lightweight heat-insulating silicone sheet according to claim 1, characterized in that: A pre-pressing mechanism (5) is installed on the upper surface of the frame (2) on one side of the mold opening mechanism (4), and a press (6) is provided on the side of the frame (2) close to the pre-pressing mechanism (5). The conveying mechanism (3) includes a conveying frame (31), with rollers (32) embedded in the upper surface of the conveying frame (31). The two side walls of the conveying frame (31) are provided with sliding grooves (33). A slot (34) is provided above the end of the sliding groove (33) away from the press (6). Limiting mechanisms (35) are installed on both side walls of the conveying frame (31).

4. The method for preparing the high-temperature resistant lightweight heat-insulating silicone sheet according to claim 3, characterized in that: The limiting mechanism (35) includes a limiting block (351), which is hook-shaped. A limiting groove (352) is provided on one side of the top of the limiting block (351). A rotating shaft (353) is provided through the bottom of the limiting block (351). One end of the rotating shaft (353) is connected to a motor (354). There are several limiting mechanisms (35), which are arranged symmetrically in pairs on both sides of the two fixing rods (72) on the side wall of the female mold (7).

5. The method for preparing the high-temperature resistant lightweight heat-insulating silicone sheet according to claim 4, characterized in that: The limiting groove (352) is semi-circular. The inner diameter of the limiting groove (352) is adapted to the outer diameter of the fixing rod (72). The limiting block (351) is engaged with the fixing rod (72) through the limiting groove (352). One end of the rotating shaft (353) passes through the limiting block (351) and is connected to the shaft end of the motor (354). The other end of the rotating shaft (353) is rotatably connected to the conveyor frame (31) through a bearing.

6. The method for preparing the high-temperature resistant lightweight heat-insulating silicone sheet according to claim 3, characterized in that: The pre-compression mechanism (5) includes a pre-compression bracket (51), a movable plate (52) is connected to the middle of the pre-compression bracket (51), a counterweight (53) is connected to the bottom of the movable plate (52) away from the pre-compression bracket (51), a first pin (54) is provided through the movable plate (52) and the pre-compression bracket (51), a fixed frame (55) is installed in the middle of the side wall of the pre-compression bracket (51), an electric telescopic rod (56) is connected to the top of the fixed frame (55), a second pin (57) is provided through the fixed frame (55) at one end of the electric telescopic rod (56), and a movable ring (58) is connected to the center of the upper surface of the movable plate (52) at the other end of the electric telescopic rod (56).

7. The method for preparing the high-temperature resistant lightweight heat-insulating silicone sheet according to claim 6, characterized in that: The preload bracket (51) is installed on the upper surface of the frame (2). The movable plate (52) is rectangular. One end of the movable plate (52) is rotatably connected to the preload bracket (51) via the first pin (54). The counterweight (53) corresponds to the middle position of the conveyor frame. One end of the electric telescopic rod (56) is rotatably connected to the fixed frame (55) via the second pin (57). The telescopic end of the electric telescopic rod (56) is movably connected to the center of the upper surface of the movable plate (52) via the movable ring (58).

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