[0031] Example 1: In this example, a hot-pressing filling device is used to perform powder filling and hot-pressing operations of the organic fiber felt, such as Figure 1 to Figure 5As shown, the hot-pressing filling device includes a frame 1 on which a guide frame 11 and a bearing block 5 are arranged, a hydraulic cylinder 2 is arranged in the center of the top of the guide frame 11, and a telescopic rod of the hydraulic cylinder 2 is provided. There is an upper pressing block 3 at the bottom, the four corners of the upper pressing block 3 are all slidably connected with the guide frame 11, and a circulating laminar flow assembly is arranged on the upper part of the upper pressing block 3, and the circulating laminar flow assembly passes the circulating air flow. The hot powder is uniformly dispersed, and the air flow containing the auxiliary heat insulating powder passes horizontally above the hot-pressing groove 32. The lower part of the upper pressing block 3 is provided with a hot-pressing groove 32. During hot pressing, the hot pressing groove 32 is sealed and slidingly connected with the bearing block 5 , and a plurality of one-way air intake components are evenly arranged between the hot pressing groove 32 and the circulating laminar flow component, which are only formed in the hot pressing groove 32 When under negative pressure, the one-way air intake assembly guides the airflow containing the auxiliary heat insulation powder into the organic fiber felt from the circulating laminar flow assembly, and the side wall of the lower pressing block is also provided with a one-way valve II 322, The second one-way valve 322 communicates with the hot-pressing groove 32 . A communication pipe 321 is also communicated with the side wall of the hot-pressing groove 32 , and a solenoid valve is provided on the communication pipe 321 .
[0032] The circulating laminar flow assembly includes a circulating cavity 31 , a partition plate 33 is arranged in the upper pressing block 3 , and the circulating cavity 31 and the hot pressing groove 32 are separated by the partition plate 33 . The air inlet hood 41 and the air return hood 42 are respectively connected, the outer end of the air inlet hood 41 is connected with the fan 4, and a circulation pipe 43 is communicated between the fan 4 and the air return hood 42, and the one-way air intake assembly is provided with On the partition plate 33, the one-way air intake assembly is connected to the hot-pressing groove 32 and the circulation cavity 31, the air inlet cover 41 is connected to a feeding pipe 411, and the upper end of the feeding pipe 411 is connected to an automatic quantitative feeding device. The top of the upper pressing block 3 is provided with a one-way valve 311 , and the one-way valve 311 communicates with the circulation chamber 31 .
[0033] The one-way air intake assembly includes a one-way valve 36 arranged on the partition plate 33, the upper end of the one-way valve 36 is connected to the circulation chamber 31, and the lower end of the one-way valve 36 is connected to the suction pipe 61. The pipe 61 is arranged on the top of the hot-pressing groove 32 , and the lower part of the suction pipe 61 is provided with several air outlet holes 62 . A plurality of resistance wires 331 are arranged in the partition plate 33 , and a plurality of resistance wires 51 are arranged in the bearing block 5 .
[0034] Utilize the above-mentioned hot pressing filling device to prepare vacuum insulation panels, and the specific steps are as follows:
[0035] S1. Use a conventional carding process to card the organic fibers, and then stack them to a thickness of 10 cm to obtain a fluffy felt; in this embodiment, the organic fibers are mixed fibers of polyester fibers and 4080 fibers, and the weight of polyester fibers and 4080 fibers is The ratio was 8:2; the fiber length was 15 mm, and the fiber diameter was 30 μm.
[0036] S2. The hot-pressing filling device is used to compress the fluffy felt material without heating. After the hot-pressing filling device compresses the fluffy felt material, the auxiliary heat insulating powder is sucked into the fluffy felt material when the pressure is lifted and released to obtain a filling felt material; The auxiliary heat insulating powder is fumed silica powder, and the particle size of the auxiliary heat insulating powder is 10 μm. The filling amount of the auxiliary heat insulating powder is 1% of the weight of the fluffy felt, and the specific filling method is as follows: use the automatic quantitative feeding device to put the fumed silica powder into the air inlet hood 41, automatically close the feeding pipe 411, turn on the fan 4, The blower 4 blows the fumed silica powder into the circulation chamber 31, and circulates and disperses through the air return hood 42 and the circulation pipe 43 until a uniform particle airflow is formed with the air, and the particle airflow continuously flows horizontally above the check valve 36. Subsequently, the fluffy felt material is placed on the bearing block 5, and at room temperature, the hydraulic cylinder 2 is opened, and the upper pressing block 3 is pressed down until the upper pressing block 3 is sealed and slidingly connected with the bearing block 5. At this time, the communication is opened through the solenoid valve. Pipe 321, during the downward process of the upper pressing block 3, the air between the upper pressing block 3 and the bearing block 5 is discharged through the communication pipe 321 and the second one-way valve 322, and the fluffy felt material is compressed with the discharge of the air until the fluffy felt is compressed. When the pressure is 0.02MPa, the hydraulic cylinder 2 is closed, and the pressure holding time is 5min. When the pressure is maintained, the communication pipe 321 is closed. At this time, the suction pipe 61 is completely inserted into the fluffy felt material. After the pressure is maintained, the hydraulic cylinder 2 is opened, and the pressure block 3 is slowly lifted up. Air cannot be introduced into the hot-pressing tank 32, and negative pressure is formed in the hot-pressing tank 32. At this time, the one-way valve 36 is opened, and the air flow containing the auxiliary insulating powder in the circulation cavity 31 flows downward through the one-way valve 36 and inhales. The air outlet 62 on the pipe 61 enters the compressed felt material, and the auxiliary heat insulation powder is filled into the felt material with the airflow, and spreads outward with the suction pipe 61 as the center. When the filling amount is appropriate, open the communication pipe 321, The negative pressure in the hot-pressing tank 32 decreases rapidly, and the suction amount of the auxiliary insulating powder also decreases rapidly. When the air pressure in the hot-pressing tank 32 and the circulation chamber 31 are equal, the check valve 36 is closed, and the auxiliary insulating powder is contained. The airflow of the material cannot descend into the hot pressing tank 32, and the filling operation stops. Continue to lift the upper pressing block 3 until the suction pipe 61 is completely separated from the compressed felt, and close the hydraulic cylinder 2 . Since there is no heating in S2, 4080 fibers are not thermally fused to bond polyester fibers, and the fluffy felt has a high rebound rate after compression, which provides space for the uniform diffusion of auxiliary thermal insulation powder.
[0037] S3. Use a hot-pressing filling device to continue hot-pressing the primary filling felt, and then fill the primary filling felt with auxiliary heat insulation powder again during the process of lifting and decompressing after hot pressing. The filling amount of the auxiliary heat insulation powder in S3 is: 1/5~1/20 of S2, obtain the secondary filling felt; the specific filling method is: heating the resistance wire 1 331 and the resistance wire 2 51 with electricity until the temperature of the separator 33 and the bearing block 5 reaches 130 ℃, turn on the hydraulic pressure Cylinder 2, press down once to fill the felt material to a pressure of 0.02MPa, close the hydraulic cylinder 2, and hold the pressure for 5min. After compression and setting, the pressing block 3 is lifted up, and negative pressure is formed in the hot-pressing groove 32. The airflow containing the auxiliary heat insulating powder is sucked into the felt material once again. Since the felt material is bonded and shaped after being compressed, the volume is greatly reduced. The total volume of pores in the felt material decreases. If the auxiliary heat insulating powder is filled too much, the powder will accumulate in the felt material near the air outlet 62 or the suction pipe 61, resulting in uneven filling. Therefore, the filling amount of the auxiliary heat insulating powder should be smaller than that in S2, and the filling amount of the auxiliary heat insulating powder in S3 is 1/5 of that in S2. By opening the communication pipe 321 in advance, the airflow containing the auxiliary heat insulating powder can be reduced. Suction volume to control the filling amount of supplemental insulation powder. When the one-way valve 36 is closed, the air pressure in the circulation chamber 31 will be lower than that of the outside because the air flow is sucked out. At this time, the one-way valve 311 is opened, and the outside air is supplied into the circulation chamber 31 until it reaches the air pressure. Valve one 311 is closed. Each time the check valve 36 is closed, it means that the filling operation is over, and the auxiliary heat insulating powder is supplemented into the air inlet hood 41 by the automatic quantitative feeding device. The density is kept constant so that the fill volume can be controlled by controlling the intake volume of the airflow. The filling amount of the auxiliary heat insulating powder can be calculated by measuring the powder particle density in the circulation cavity 31. The particle density difference before and after hot pressing is multiplied by the cavity volume of the circulating laminar flow component. Powder weight in organic fiber mat. After hot pressing, the auxiliary thermal insulation powder is replenished in time to ensure the constant particle density in the circulating laminar flow assembly.
[0038] S4. After the secondary filling felt is completely depressurized and cooled, it is dried to become the core material. The conventional method is used to add a getter and coat a high-resistance film, and vacuum and plastic seal to obtain a vacuum insulation board.
