Nanofiber heat preservation and insulation cotton and testing device thereof

Abstract

The invention relates to the technical field of heat preservation and insulation new material testing, in particular to nanofiber heat preservation and insulation cotton and a testing device thereof, and the heat preservation and insulation cotton is prepared from polypropylene, polyethylene glycol terephthalate, EVA hot melt adhesive and decahydronaphthalene; the thermal insulation cotton testing device comprises a rack and a transposition disc installed at the top of the rack, a U-shaped support is fixedly erected in the middle of the top of the rack, detection driving assemblies are arranged on the two sides of the U-shaped support, and a thermal conductivity testing assembly and a pressure testing assembly are arranged at the positions, corresponding to the two detection driving assemblies, of the top of the transposition disc respectively. The two detection driving assemblies are linked, and the thermal conductivity test assembly and the pressure test assembly respectively form a thermal conductivity detection mechanism and a pressure detection mechanism with the detection driving assemblies at corresponding positions; according to the invention, a pressure test and a thermal conductivity test can be carried out at the same time, and the prepared thermal insulation cotton has the characteristics of low density, special structure and high resilience.

Description

Technical Field

[0001] The invention relates to the technical field of testing new thermal insulation materials, in particular to a nanofiber thermal insulation cotton and a testing device thereof. Background Art

[0002] So far, PP, PET, polyurethane and other porous fibers and foam materials are the most representative and widely used non-high temperature resistant thermal insulation materials known to us. The principle of thermal insulation materials is the density of the material and how many air layers it can store. Since air is the best thermal insulation medium in nature (thermal conductivity is about 0.0267W / mK), the key to high-performance thermal insulation materials is that the material must have an extremely low density, a special internal structure and be able to maintain its fixed shape to maintain this density. Generally speaking, it is very difficult for extremely low-density materials to be elastic, soft and maintain their shape because there is very little internal material, and a very special structure is required to achieve this.

[0003] For example, most existing synthetic fiber thermal clothing is filled with relatively coarse fibers, which can maintain elasticity and shape, but the density is large and the internal structure does not conform to the scientific thermal insulation structure. In addition, although the down in the down jacket has excellent thermal insulation performance, the disadvantage is that it cannot be washed, which greatly limits its scope of outdoor and military use.

[0004] The prior art discloses a Chinese patent with publication number CN 105420836 B (IPC classification number D01F6 / 92): a thermal insulation cotton and a preparation method thereof, wherein the thermal insulation cotton is composed of 90.2-94.5% of recycled polylactic acid fiber and 5.5-9.8% of adhesive. The preparation method of the thermal insulation cotton comprises: melting and re-granulating the polylactic acid scraps to obtain recycled polylactic acid pellets; drying the recycled polylactic acid pellets and feeding them into a melt spinning machine for spinning, and then heat-setting, curling and cutting to obtain recycled polylactic acid fibers, wherein the heat setting is divided into three zones, and the total heat setting time of the three zones is 8-12 minutes; pre-treating the recycled polylactic acid fibers, and preparing the thermal insulation cotton through the processes of opening, mixing, combing, cross-laying, reinforcing, curing, slitting and winding.

[0005] The prior art discloses a Chinese patent with publication number CN 209624239 U (IPC classification number G01N3 / 08): a thermal insulation cotton compression testing machine, and discloses a machine base, a controller, a support base, a lower pressure base and a driving mechanism; the machine base has a workbench and a column arranged on the workbench, a accommodating space is formed on the front side of the lower end of the column, a plurality of guide columns are arranged on the workbench, and the plurality of guide columns are located in the accommodating space; the support base is arranged on the workbench and located in the accommodating space, a top surface of the support base has a placement position for placing the thermal insulation cotton, and a pressure sensor is arranged at the bottom of the support base, the pressure sensor is connected to the controller, a displacement sensor is arranged on the side of the placement position, the displacement sensor is connected to the controller, and the displacement sensor protrudes from the surface of the placement position.

[0006] However, the above-mentioned prior art still has certain defects, such as the high density of the thermal insulation cotton, the lack of high resilience, and the internal thermal insulation structure is easily damaged by the external environment;

[0007] For example, the testing machine can only test the pressure. When the thermal conductivity test is needed, it needs to be tested through another testing equipment. The production test process is complicated, the actual production process is troublesome to operate, inconvenient to use, and the production test cost is high. Summary of the invention

[0008] The purpose of the present invention is to provide a nanofiber thermal insulation cotton and a testing device thereof to solve the problems raised in the above background technology.

[0009] The purpose of the present invention can be achieved through the following technical solutions:

[0010] A nanofiber thermal insulation cotton, the thermal insulation cotton comprising the following components: polypropylene, polyethylene terephthalate, EVA hot melt adhesive and decalin;

[0011] Adding EVA hot melt adhesive to polypropylene to prepare a first spinning solution, adjusting the viscosity of the prepared first spinning solution to less than 50 Pa·s within a shear rate range of 1000 to 10000 1 / s, and melt-blowing the first spinning solution using a melt-blowing device to obtain a first polymer fiber;

[0012] Adding decalin to polyethylene terephthalate to prepare a second spinning solution, adjusting the viscosity of the prepared second spinning solution to less than 150 mPa·s within a shear rate range of 1000 to 10000 1 / s, and flash evaporating the second spinning solution using a flash evaporation device to obtain a second polymer fiber;

[0013] Under the traction of a fan, the first polymer fiber and the second polymer fiber are evenly mixed using multiple air nozzles, and then sprayed out through a spinneret to obtain fibers with an average fiber diameter of 0.8-1μm and a normal fiber diameter distribution. The prepared fibers are then opened, vibrated, combed, laid, glued, dried and ironed to obtain nanofiber thermal insulation cotton.

[0014] The present invention also provides a test device for nanofiber thermal insulation cotton, which is used to test the above-mentioned nanofiber thermal insulation cotton, including a frame, a U-shaped bracket is fixedly mounted on the middle of the top of the frame, and a circular groove is opened on the top surface of the frame, a transposition disk is movably sleeved inside the circular groove, a drive motor 1 is fixedly installed at the bottom of the frame, the output shaft end of the drive motor 1 movably passes through the frame, and the output shaft end of the drive motor 1 is fixedly connected to the transposition disk, and two groups of thin film temperature sensors are fixedly embedded on the top of the transposition disk;

[0015] Detection drive components are provided on both sides of the U-shaped bracket, and the two detection drive components are centrally symmetrically arranged about the axis of the transposition disk. A thermal conductivity test component and a pressure test component are respectively arranged at the positions corresponding to the two detection drive components on the top of the transposition disk. The two detection drive components are linked to each other. The thermal conductivity test component and the pressure test component respectively form a thermal conductivity detection mechanism and a pressure detection mechanism with the detection drive components at the corresponding positions. Wireless signal transmitters are installed on the thermal conductivity test component and the pressure test component.

[0016] In a preferred embodiment, the detection drive assembly includes a horizontal plate fixed on the side of the U-shaped bracket and two vertical plates fixed on the inner top surface of the U-shaped bracket. A vertical axis is movably penetrated through the end of the horizontal plate away from the U-shaped bracket. Two limiting baffles are fixedly sleeved on the outer peripheral surface of the top end of the vertical axis, which are respectively fitted with the upper and lower surfaces of the horizontal plate. A linkage part is arranged between the vertical axes on the two detection drive assemblies.

[0017] In a preferred embodiment, the linkage part includes a second drive motor fixedly installed at the top center position of the U-shaped bracket, the output shaft end of the second drive motor movably passes through the U-shaped bracket, and the output shaft end of the second drive motor is fixedly connected to a driving wheel, and the outer circumferences of the two vertical shafts are fixedly sleeved with driven wheels at positions corresponding to the driving wheels, and the two driven wheels are connected to the driving wheel through belt transmission.

[0018] In a preferred embodiment, a turntable is fixedly connected to the bottom end of the vertical axis, an arc-shaped convex plate is fixedly provided at the edge of the bottom end surface of the turntable, and a thin film pressure sensor is installed in the middle of the bottom of the arc-shaped convex plate and at one end of the bottom end surface edge of the turntable away from the arc-shaped convex plate.

[0019] In a preferred embodiment, a deflection unit is provided between the vertical plate and the frame on the detection drive assembly, and the deflection unit includes a side plate fixedly provided on the top of the frame and a deflection rod rotatably installed between the two vertical plates through a bearing, and a deflection block is fixedly sleeved on the outer circumference of the deflection rod at a position between the two vertical plates;

[0020] A rocker rod and a ball seat rod are fixedly connected to the middle parts of both sides of the deflection block respectively, a round ball is fixedly connected to the end of the ball seat rod, a U-shaped rod is fixedly provided on the outer peripheral surface of one end of the deflection rod close to the side plate, a ring is movably sleeved in the middle part of the U-shaped rod, and a spring is fixedly connected between the ring and the side plate.

[0021] In a preferred embodiment, the thermal conductivity testing assembly includes an isolation cover fixedly connected to the end of the rocker arm on the corresponding position detection drive assembly, a cylinder is fixedly installed at the center position of the top of the inner cavity of the isolation cover, and the telescopic end of the cylinder is fixedly connected to an electric heating plate.

[0022] In a preferred embodiment, the pressure test assembly includes a top plate fixedly connected to the end of the rocker on the corresponding position detection drive assembly, a limit frame is fixedly sleeved on the side of the top plate, and a pressure plate is arranged inside the cavity between the top plate and the limit frame, corner plates are fixedly arranged at the four corners of the top of the limit frame, and guide columns are fixedly arranged at the four corners of the top of the pressure plate;

[0023] The top end of the guide column moves through the top plate and the angle plate at the corresponding position in sequence, a circular plate is fixedly provided on the top end surface of the guide column, and a spring 2 is fixedly connected to the side surface of the guide column located between the angle plate and the circular plate. A pressure portion is provided between the top plate and the pressure plate, and a thin film pressure sensor 2 is installed at the bottom of the pressure plate.

[0024] In a preferred embodiment, the pressure-applying portion includes a core shaft mounted on a limit frame for horizontal rotation via a bearing, and a fixed sleeve is provided on the peripheral side of the core shaft with two groups of cams axially symmetrically arranged with respect to the vertical axial section of the pressure plate, with three cams in each group, and the three cams in each group are arranged to shrink in sequence along the axial direction of the core shaft, and a drive motor three is fixedly mounted on one side of the limit frame, and the output shaft end of the drive motor three is fixedly connected to one end of the core shaft.

[0025] In a preferred embodiment, a cooling mechanism is arranged between the thermal conductivity test assembly and the pressure test assembly, and the cooling mechanism includes an L-shaped bracket fixed to the top of the frame, and the top end surface of the inner side of the L-shaped bracket is fixedly connected to a hollow fan ring plate, and the bottom end surface of the fan ring plate is provided with multiple groups of air outlet slots, and an air pump and a push switch are installed on the top of the L-shaped bracket.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention uses a driving motor 1 to drive the thermal insulation cotton sample to be tested on the transposition disk to transpose between the thermal conductivity test component and the pressure test component, and cooperates with the detection drive component to intermittently drive the thermal conductivity test component and the pressure test component to press down synchronously, so as to complete the pressure test of the sample and the thermal conductivity test of the sample before and after being pressed, so as to judge the quality of the target thermal insulation cotton;

[0028] 2. The present invention provides a cooling mechanism between the thermal conductivity test assembly and the pressure test assembly, and can use the ball on the pressure detection mechanism to enter the horizontal plane area on the arc-shaped convex plate at the position to apply pressure to the push switch on the L-shaped bracket, thereby starting the air pump to inject air into the inner cavity of the fan ring plate, and then blow it out from the air outlet slot on the bottom end surface of the fan ring plate, so that the sample that has completed the thermal conductivity test is cooled by air during the transfer process, so as to avoid the sample with residual temperature directly entering the pressure test station for testing and affecting the result;

[0029] 3. The present invention controls the average diameter of the fibers and the ratio of thick and thin fibers in the aggregate during the production process, and uses a series of fiber shaping methods to make the prepared nanofiber thermal insulation cotton have the characteristics of low density, special structure and high resilience. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a schematic diagram of the overall structure of the testing device of the present invention from a first viewing angle;

[0032] Figure 2 is a schematic diagram of the overall structure of the testing device of the present invention from a second viewing angle;

[0033] Figure 3 It is a schematic diagram of the structure of the detection drive component of the test device of the present invention from a first perspective;

[0034] Figure 4 is a schematic diagram of the structure of the detection drive component of the test device of the present invention from a second viewing angle;

[0035] Figure 5 It is a schematic diagram of the structure of the thermal conductivity detection mechanism of the testing device of the present invention;

[0036] Figure 6 is a top view of the thermal conductivity detection mechanism of the testing device of the present invention;

[0037] Figure 7 The present invention Figure 6 Schematic diagram of the AA section structure;

[0038] Figure 8 It is a schematic diagram of the structure of the pressure detection mechanism of the testing device of the present invention;

[0039] Fig. 9 is a top view of the pressure detection mechanism of the testing device of the present invention;

[0040] Fig.10 The present invention Fig. 9 Schematic diagram of the cross-section structure along the BB axis;

[0041] Fig.11 is a top view of a pressure test assembly of a test device of the present invention;

[0042] Fig.12 The present invention Fig.11 Schematic diagram of the CC section structure;

[0043] Fig.13 It is a schematic structural diagram of the cooling mechanism of the testing device of the present invention from a first perspective;

[0044] Fig.14 is a schematic structural diagram of the cooling mechanism of the testing device of the present invention from a second viewing angle;

[0045] Fig.15 It is a schematic diagram of the frame and the transposition plate of the test device of the present invention;

[0046] Fig.16 This is a production and finishing flow chart of the nanofiber thermal insulation cotton of the present invention;

[0047] Fig.17 is a schematic diagram of the flash spray method for preparing nanofibers in the present invention;

[0048] Fig.18 is a SEM microscope photo of the fiber prepared by the best embodiment of the present invention;

[0049] Fig.19 is a degree distribution diagram of the fiber prepared by the best embodiment of the present invention;

[0050] Fig. 20 is a graph of thermal conductivity of a fiber assembly of fibers prepared in accordance with a preferred embodiment of the present invention;

[0051] Fig.21 3 is a thermal resistance diagram of a fiber assembly of fibers prepared according to the best embodiment of the present invention.

[0052] The reference numerals in the figure are as follows: 1, frame; 2, U-shaped bracket; 3, round groove; 4, transposition plate; 5, film temperature sensor; 6, detection drive assembly; 61, horizontal plate; 62, vertical plate; 63, vertical axis; 64, limit stop plate; 65, turntable; 66, arc convex plate; 67, driving wheel; 68, driven wheel; 69, deflection rod; 610, deflection block; 611, rocker rod; 612, ball; 613, U-shaped rod; 614, collar; 615, side plate; 616, spring one; 617, film pressure sensor one; 7, thermal conductivity test assembly; 71 , electric heating plate; 72, cylinder; 73, isolation cover; 8, pressure test assembly; 81, top plate; 82, limit frame; 83, pressure plate; 84, guide column; 85, angle plate; 86, round plate; 87, spring 2; 88, core shaft; 89, cam; 810, thin film pressure sensor 2; 9, cooling mechanism; 91, L-shaped bracket; 92, fan ring plate; 93, air outlet slot; 94, air pump; 95, push switch; 10, wireless signal transmitter; 11, melt-blown equipment; 111, flash evaporation equipment; 112, air nozzle; 113, cord fabric; 114, fan. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] A testing device for nanofiber thermal insulation cotton is characterized by applying stable pressure to test the performance of new energy-saving thermal insulation materials, and its IPC classification number is G01N3 / 08.

[0055] Example 1

[0056] Refer to the instruction manual Figure 1-2 and Fig.15 , a test device for nanofiber thermal insulation cotton according to an embodiment of the present invention, the test device is used to test the above-mentioned nanofiber thermal insulation cotton, comprising a frame 1, a U-shaped bracket 2 is fixedly mounted on the middle of the top of the frame 1, and a circular groove 3 is opened on the top surface of the frame 1, and a transposition disk 4 is movably sleeved inside the circular groove 3, a driving motor 1 is fixedly installed at the bottom of the frame 1, the output shaft end of the driving motor 1 movably passes through the frame 1, and the output shaft end of the driving motor 1 is fixedly connected to the transposition disk 4, and two sets of thin film temperature sensors 5 are fixedly embedded on the top of the transposition disk 4;

[0057] Detection drive components 6 are provided on both sides of the U-shaped bracket 2, and the two detection drive components 6 are centrally symmetrically arranged about the axis of the transposition disk 4. A thermal conductivity test component 7 and a pressure test component 8 are respectively arranged at the positions corresponding to the two detection drive components 6 on the top of the transposition disk 4. The two detection drive components 6 are linked to each other. The thermal conductivity test component 7 and the pressure test component 8 respectively form a thermal conductivity detection mechanism and a pressure detection mechanism with the detection drive components 6 at the corresponding positions. Wireless signal transmitters 10 are installed on the thermal conductivity test component 7 and the pressure test component 8.

[0058] It should be noted that the present invention utilizes a driving motor to drive the thermal insulation cotton sample to be tested (hereinafter referred to as sample) on the transposition disk 4 to transpose between the thermal conductivity test component 7 and the pressure test component 8, and cooperates with the detection drive component 6 to intermittently drive the thermal conductivity test component 7 and the pressure test component 8 to press down synchronously, thereby completing the pressure test of the sample and the thermal conductivity test of the sample before and after being pressed, thereby determining the performance of the target thermal insulation cotton.

[0059] Specifically, Figure 1-4 As shown, the detection drive assembly 6 includes a horizontal plate 61 fixed to the side of the U-shaped bracket 2 and two vertical plates 62 fixed to the top surface of the inner side of the U-shaped bracket 2. A vertical shaft 63 is movably penetrated at one end of the horizontal plate 61 away from the U-shaped bracket 2. Two limiting baffles 64 respectively fitted with the upper surface and the lower surface of the horizontal plate 61 are fixedly sleeved on the outer peripheral surface of the top end of the vertical shaft 63. A linkage part is provided between the vertical shafts 63 on the two detection drive assemblies 6.

[0060] The linkage part includes a second drive motor fixedly mounted at the top center of the U-shaped bracket 2, the output shaft end of the second drive motor movably passes through the U-shaped bracket 2, and the output shaft end of the second drive motor is fixedly connected to a driving wheel 67, and the outer circumferences of the two vertical shafts 63 are fixedly sleeved with driven wheels 68 at positions corresponding to the driving wheels 67, and the two driven wheels 68 are connected to the driving wheel 67 through belt transmission;

[0061] A rotating disk 65 is fixedly connected to the bottom end of the vertical shaft 63, and an arc-shaped convex plate 66 is fixedly provided at the edge of the bottom end surface of the rotating disk 65. A thin film pressure sensor 617 is installed at the middle of the bottom of the arc-shaped convex plate 66 and at one end of the bottom end surface edge of the rotating disk 65 away from the arc-shaped convex plate 66.

[0062] A deflection unit is provided between the vertical plate 62 on the detection drive assembly 6 and the frame 1, and the deflection unit includes a side plate 615 fixedly provided on the top of the frame 1 and a deflection rod 69 rotatably installed between the two vertical plates 62 through a bearing, and a deflection block 610 is fixedly sleeved on the outer circumference of the deflection rod 69 at a position between the two vertical plates 62;

[0063] A rocker rod 611 and a ball seat rod are fixedly connected to the middle parts of both sides of the deflection block 610, and a round ball 612 is fixedly connected to the end of the ball seat rod. A U-shaped rod 613 is fixedly provided on the outer peripheral surface of one end of the deflection rod 69 close to the side plate 615. A ring 614 is movably sleeved in the middle of the U-shaped rod 613, and a spring 616 is fixedly connected between the ring 614 and the side plate 615.

[0064] It should be noted that in order to ensure that the ball 612 switches smoothly between the rotating disk 65 and the arc-shaped convex plate 66, the arc-shaped convex plate 66 should be set to an isosceles trapezoidal structure, and when the U-shaped rod 613 is in Figure 3 In the state shown, the spring 1 616 is in a stretched state, and the thermal conductivity test assembly 7 and the pressure test assembly 8 are installed at the corresponding position on the end of the swing rod 611 away from the deflection block 610. When the thermal conductivity test assembly 7 and the pressure test assembly 8 are synchronously pressed down by the detection drive assembly 6 to test the sample, the driving motor 2 is used to drive the driving wheel 67 to rotate, thereby driving the two vertical shafts 63 to rotate synchronously with the driven wheel 68, and then driving the turntable 65 to rotate. The rotation process of the turntable 65 can be composed of the following two parts:

[0065] In process 1, when the rotating disk 65 rotates to the area where the edge of its bottom end surface is away from the arc-shaped convex plate 66 and contacts the ball 612, the deflection block 610 deflects to the position as shown in FIG. Figure 3 In the state shown, at this time, the thermal conductivity test assembly 7 and the pressure test assembly 8 at the ends of the two swing rods 611 are respectively buckled on the samples at the corresponding positions, and the ball 612 in this state will be pressed and contacted with the film pressure sensor 1 617 in the area where the bottom surface of the turntable 65 is located. The film pressure sensor 1 617 that detects the pressure signal will transmit the signal to the control end, and the control end will issue an instruction to control the thermal conductivity test assembly 7 and the pressure test assembly 8 to simultaneously perform thermal conductivity detection and pressure detection on the samples at the locations. The test state in this process will continue until the ball 612 is completely out of the pressed contact state with the film pressure sensor 1 617 in the current area;

[0066] Process 2: When the ball 612 leaves the area of ​​the turntable 65 and enters the state of contacting the arc-shaped convex plate 66, the ball 612 will enter the horizontal plane area through the inclined area on the arc-shaped convex plate 66. In this process, as the turntable 65 rotates, the ball 612 will be gradually pressed downward to drive the deflection block 610 to move axially away from the side plate 615 at the position with the deflection rod 69 as the center, thereby driving the U-shaped rod 613 at the end of the deflection rod 69 at the position to deflect synchronously and stretch the spring 1 616. The thermal conductivity test assembly 7 and the pressure test assembly 8 gradually break away from the buckling state of the sample as the swing rod 611 at the position deflects upward. When the ball 612 completely enters the horizontal plane area on the arc-shaped convex plate 66, the thermal conductivity test assembly 7 and the pressure test assembly 8 completely break away from the buckling state of the sample at the position.

[0067] When the turntable 65 rotates until the ball 612 is in crimping contact with the thin film pressure sensor 617 on the arc-shaped convex plate 66, the thin film pressure sensor 617 that detects the pressure signal will transmit the signal to the control end, and the control end will issue a command to start the drive motor to drive the transposition disk 4 to rotate 180°, thereby transposing the samples of the thermal conductivity test station and the pressure test station, and then repeating the above process as the ball 612 leaves the area of ​​the arc-shaped convex plate 66.

[0068] Furthermore, in the above process, both ends of the horizontal plane area on the arc-shaped convex plate 66 are vacant areas (i.e., areas not covered by the thin film pressure sensor 617 at the location). If the same sample completes two rounds of testing at both the thermal conductivity testing station and the pressure testing station, it will be replaced with a new sample to be tested before the second round of pressure testing is completed and the station is switched. In this way, the sample can be pressure tested and the thermal conductivity tested before and after the sample is pressurized, thereby determining the quality of the target thermal insulation cotton.

[0069] Specifically, Figure 2 and Figure 5-7 As shown, the thermal conductivity test assembly 7 includes an isolation cover 73 fixedly connected to the end of the rocker 611 on the corresponding position detection drive assembly 6, a cylinder 72 is fixedly installed at the center position of the top of the inner cavity of the isolation cover 73, and the telescopic end of the cylinder 72 is fixedly connected to the electric heating plate 71.

[0070] It should be noted that, in the process of testing the thermal conductivity of the sample, when the turntable 65 is rotated to the area where the ball 612 and the thin film pressure sensor 617 are located in the area where the bottom surface is located, the thin film pressure sensor 617 that detects the pressure signal will transmit the signal to the control end, and the control end will issue an instruction to control the cylinder 72 to push the electric heating plate 71 to contact the upper surface of the sample to heat the upper surface of the test sample. At the same time, the thin film temperature sensor 5 at the location is started to detect the temperature of the lower surface of the test sample, so as to judge the thermal conductivity of the sample. In addition, in the process of thermal conductivity detection, the sample is covered with an isolation cover 73 to avoid affecting the test results in an open environment.

[0071] Specifically, Figure 1 and Figure 8-12 As shown, the pressure test assembly 8 includes a top plate 81 fixedly connected to the end of the swing rod 611 on the corresponding position detection drive assembly 6, a limit frame 82 is fixedly sleeved on the side of the top plate 81, and a pressure plate 83 is arranged inside the cavity between the top plate 81 and the limit frame 82, corner plates 85 are fixedly arranged at the four corners of the top of the limit frame 82, and guide pillars 84 are fixedly arranged at the four corners of the top of the pressure plate 83;

[0072] The top of the guide post 84 is movable and passes through the top plate 81 and the angle plate 85 at the corresponding position in sequence. A circular plate 86 is fixedly arranged on the top surface of the guide post 84. A second spring 87 is fixedly connected to the side of the guide post 84 between the angle plate 85 and the circular plate 86. A pressure applying part is arranged between the top plate 81 and the pressure plate 83. A second film pressure sensor 810 is installed at the bottom of the pressure plate 83.

[0073] The pressure-applying portion includes a core shaft 88 which is horizontally rotatably mounted on a limit frame 82 via a bearing. Two groups of cams 89 are axially symmetrically arranged about the vertical axial section of the pressure plate 83 and are fixedly sleeved on the side surface of the core shaft 88. Each group has three cams, and the three cams 89 in each group are successively reduced along the axial direction of the core shaft 88. A drive motor three is fixedly mounted on one side of the limit frame 82, and the output shaft end of the drive motor three is fixedly connected to one end of the core shaft 88.

[0074] It should be noted that, in the process of pressure testing the sample, when the turntable 65 is rotated to the area where the ball 612 and the film pressure sensor 617 are located in the area where the bottom surface is located, the film pressure sensor 617 that detects the pressure signal will transmit the signal to the control end, and the control end will issue a command to control the drive motor 3 to drive the core shaft 88 to rotate, thereby driving the cam 89 on the outside of the core shaft 88 to intermittently press the pressure plate 83, so that the pressure plate 83 drives the guide column 84 to move downward synchronously and compress the spring 2 87 at the corresponding position, thereby realizing vibration pressure testing of the sample. In addition, in the process of pressure testing, the sample is covered with a limit frame 82 to avoid uneven force on the sample when testing in an open environment, which may affect the test results.

[0075] Example 2

[0076] Refer to the instruction manual Figure 1-2 and Figure 13-14 A testing device for a nanofiber thermal insulation cotton according to an embodiment of the present invention, a cooling mechanism 9 is arranged between the thermal conductivity testing component and the pressure testing component 8, the cooling mechanism 9 comprises an L-shaped bracket 91 fixed to the top of the frame 1, a hollow fan ring plate 92 is fixedly connected to the top inner surface of the L-shaped bracket 91, a plurality of air outlet slots 93 are arranged on the bottom end surface of the fan ring plate 92, an air pump 94 and a push switch 95 are installed on the top of the L-shaped bracket 91.

[0077] It should be noted that the push switch 95 is directly opposite to the ball 612 on the pressure detection mechanism, and when the ball 612 on the pressure detection mechanism begins to enter the horizontal plane area on the arc-shaped convex plate 66 at the location, the ball 612 applies pressure to the push switch 95 on the L-shaped bracket 91, thereby starting the air pump 94 to inject air into the inner cavity of the fan ring plate 92, and then blown out from the air outlet slot 93 on the bottom end surface of the fan ring plate 92, so that the samples that have completed the thermal conductivity test are air-cooled during the transfer process to prevent the samples with residual temperature from directly entering the pressure test station for testing and affecting the results. On the contrary, when the ball 612 on the pressure detection mechanism leaves the horizontal plane area on the arc-shaped convex plate 66 at the location, the ball 612 separates from the push switch 95. At this time, the air pump 94 stops supplying air, and when the ball 612 at the location presses the push switch 95 for the next round, the cooling mechanism 9 is started again to overcool the samples in the transfer process.

[0078] In the above technical solution, in order to better control the drive motors, a unified kinematic and electrical model is established for the drive motors 1, 2 and 3, and the expression is:

[0079]

[0080] Where, M represents the mass of the drive motor; F represents the thrust of the drive motor; v represents the speed of the mover; B represents the viscous damping coefficient; i q represents the q-axis current; F f Represents the thrust constant of the driving motor; R a Indicates the primary winding resistance of the drive motor; L q represents the primary inductance of the drive motor; τ represents the pole pitch; Φ f Represents magnetic flux.

[0081] The PID controller is used to control the drive motor. The control deviation e(t) is formed according to the motor input value r(t) and the actual output value y(t). The control deviation e(t) is calculated by proportional, integral and differential operations and linearly superimposed to form the control quantity u(t) output. In the continuous time domain, the control model of PID is:

[0082]

[0083] In the formula, k p Represents the proportionality coefficient; T i represents the integral time constant; T d Represents the differential time constant.

[0084] In order to overcome the time lag caused by the filter and inverter in the controller of the drive motor during the drive process, the current loop is equivalent to the inertia link, and its transfer function is as follows:

[0085]

[0086] Where, T rg Indicates the thrust coefficient of the drive motor; T fil Represents the filter time constant; T i Indicates the inverter time constant.

[0087] It should be noted that the present invention can accurately control the operating rhythm of the drive motor by establishing kinematic and electrical models for the drive motor, and at the same time use a PID controller to effectively control the drive motor to ensure the effectiveness of the drive motor during operation.

[0088] In the above technical scheme, the circuits, electronic components and control modules involved are all existing technologies and can be fully implemented by those skilled in the art. Needless to say, the content to be protected by the present invention does not involve improvements to software and methods.

[0089] A nanofiber thermal insulation cotton comprises the following components: polypropylene, polyethylene terephthalate, EVA hot melt adhesive and decalin.

[0090] like Figure 16-17As shown, the system for preparing nanofiber thermal insulation cotton includes a meltblowing device 11, a flash evaporation device 111, a plurality of air nozzles 112, a cord fabric 113 and a fan 114, wherein the meltblowing device 11 is used to melt-blown the first spinning solution to obtain a first polymer fiber; the flash evaporation device 111 is used to flash-evaporate the second spinning solution to obtain a second polymer fiber; the plurality of air nozzles 112 are used to mix the first polymer fiber and the second polymer fiber; at least one air nozzle 112 is arranged at the outlet of the meltblowing device 11; at least one air nozzle 112 is arranged at the outlet of the flash evaporation device 111; the fan 114 is used to pull the first polymer fiber and the second polymer fiber, and pull the first polymer fiber and the second polymer fiber to the cord fabric 113, and spray them out through a spinneret to obtain fibers with a normal fiber diameter distribution, and then the prepared fibers are subjected to opening, vibration feeding, combing, web laying, glue spraying, drying and ironing operations to obtain nanofiber thermal insulation cotton.

[0091] The fibers with a normal fiber diameter distribution and an average fiber diameter of 0.8-1 μm prepared by flash spraying are adjusted to an apparent density of 0.001-0.003 g / cm 3 When the fiber assembly is shaped like a ball, it will have the following performance parameters:

[0092] Average fiber diameter: 0.8-1μm;

[0093] Fiber diameter distribution: normal distribution;

[0094] Standard deviation: 0.3-0.4;

[0095] Fiber apparent density: 0.001-0.003g / cm 3 about;

[0096] Instantaneous rebound rate: >85%.

[0097] It should be noted that the present invention also uses 3D-CFD fluid analysis and a large number of experiments to successfully optimize the die head and spinneret, so that while controlling the average fiber diameter of a variety of polymer materials, fibers with a certain ratio can also be ejected at one time, thereby controlling the distribution and ratio of the fiber diameter.

[0098] The preparation method of the above-mentioned nanofiber thermal insulation cotton is as follows:

[0099] S1: adding EVA hot melt adhesive to polypropylene to prepare a first spinning solution, adjusting the viscosity of the prepared first spinning solution to less than 50 Pa·s within a shear rate range of 1000 to 10000 1 / s, and melt-blowing the first spinning solution using a melt-blowing device 11 to obtain a first polymer fiber;

[0100] S2: adding decalin to polyethylene terephthalate to prepare a second spinning solution, adjusting the viscosity of the prepared second spinning solution to less than 150 mPa·s within a shear rate range of 1000 to 10000 1 / s, and flash evaporating the second spinning solution using a flash evaporation device 111 to obtain a second polymer fiber;

[0101] S3: Under the traction of the fan 114, the first polymer fiber and the second polymer fiber are mixed evenly by using a plurality of air nozzles 112, and then sprayed out through a spinneret to obtain fibers with an average fiber diameter of 0.8-1 μm and a normal fiber diameter distribution. The prepared fibers are then subjected to opening, vibrating cotton feeding, combing, laying, gluing, drying and ironing operations to obtain nanofiber thermal insulation cotton.

[0102] In this embodiment, the first polymer fibers and the second polymer fibers are uniformly mixed using multiple air nozzles 112 at a material ratio of (4-6): (4-6), and the total amount is 10.

[0103] Example 1

[0104] Adding EVA hot melt adhesive to polypropylene to prepare a first spinning solution, adjusting the viscosity of the prepared first spinning solution to less than 50 Pa·s within a shear rate range of 1000 to 10000 1 / s, and melt-blowing the first spinning solution using a melt-blowing device 11 to obtain a first polymer fiber;

[0105] Adding decalin to polyethylene terephthalate to prepare a second spinning solution, adjusting the viscosity of the prepared second spinning solution to less than 150 mPa·s within a shear rate range of 1000 to 10000 1 / s, and flash evaporating the second spinning solution using a flash evaporation device 111 to obtain a second polymer fiber;

[0106] Under the traction of the fan 114, the first polymer fiber and the second polymer fiber are evenly mixed by using a plurality of air nozzles 112, and the dosage ratio of the first polymer fiber to the second polymer fiber is controlled to be 4:6, and fibers with an average fiber diameter of 0.8 μm and a normal fiber diameter distribution are obtained by spraying through a spinneret. The prepared fibers are then opened, vibrated, combed, laid, glued, dried and ironed to obtain nanofiber thermal insulation cotton.

[0107] Example 2

[0108] Adding EVA hot melt adhesive to polypropylene to prepare a first spinning solution, adjusting the viscosity of the prepared first spinning solution to less than 50 Pa·s within a shear rate range of 1000 to 10000 1 / s, and melt-blowing the first spinning solution using a melt-blowing device 11 to obtain a first polymer fiber;

[0109] Adding decalin to polyethylene terephthalate to prepare a second spinning solution, adjusting the viscosity of the prepared second spinning solution to less than 150 mPa·s within a shear rate range of 1000 to 10000 1 / s, and flash evaporating the second spinning solution using a flash evaporation device 111 to obtain a second polymer fiber;

[0110] Under the traction of the fan 114, the first polymer fiber and the second polymer fiber are mixed evenly by using a plurality of air nozzles 112, and the dosage ratio of the first polymer fiber to the second polymer fiber is controlled to be 5:5, and fibers with an average fiber diameter of 1 μm and a normal fiber diameter distribution are obtained by spraying through a spinneret. The prepared fibers are then opened, vibrated, combed, laid, glued, dried and ironed to obtain nanofiber thermal insulation cotton.

[0111] Example 3

[0112] Adding EVA hot melt adhesive to polypropylene to prepare a first spinning solution, adjusting the viscosity of the prepared first spinning solution to less than 50 Pa·s within a shear rate range of 1000 to 10000 1 / s, and melt-blowing the first spinning solution using a melt-blowing device 11 to obtain a first polymer fiber;

[0113] Adding decalin to polyethylene terephthalate to prepare a second spinning solution, adjusting the viscosity of the prepared second spinning solution to less than 150 mPa·s within a shear rate range of 1000 to 10000 1 / s, and flash evaporating the second spinning solution using a flash evaporation device 111 to obtain a second polymer fiber;

[0114] Under the traction of the fan 114, the first polymer fiber and the second polymer fiber are mixed evenly by using a plurality of air nozzles 112, and the dosage ratio of the first polymer fiber to the second polymer fiber is controlled to be 6:4, and fibers with an average fiber diameter of 0.9 μm and a normal fiber diameter distribution are obtained by spraying through a spinneret. The prepared fibers are then opened, vibrated, combed, laid, glue sprayed, dried and ironed to obtain nanofiber thermal insulation cotton.

[0115] Comparing the nanofiber thermal insulation cotton prepared in Examples 1-3, 100 fiber samples were taken from each of the prepared fibers, and the performance parameters of the fiber assemblies were measured, as follows:

[0116] Example 1 Example 2 Example 3 Average fiber diameter (μm) 0.8 1 0.9 Standard Deviation 0.3 0.3 0.4 <![CDATA[Fiber apparent density (g / cm 3 )]]> 0.001 0.002 0.003 Instantaneous rebound rate (%) 87 88 86

[0117] In summary, the average diameter of the prepared nanofibers is greater than 0.8 μm, the standard deviation is less than 0.4, the instantaneous rebound rate of the fibers is higher than 86%, the rebound effect is good, and the apparent density of the fibers is lower than 0.003 g / cm 3The nanofiber has a good overall thermal insulation effect, and the ratio used in Example 2 is the optimal ratio. At the same time, the nanofiber thermal insulation cotton prepared by the material ratio of Example 2 is tested, and the specific test results are as follows: Figure 18-21 shown.

[0118] In addition, the nanofiber thermal insulation cotton prepared by the present invention is mainly used as outdoor cold-proof clothing, gloves, bedding, etc., and has a military-grade warming effect. Of course, it can also be used as a building insulation material.

[0119] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A nanofiber thermal insulation cotton, characterized by: The thermal insulation cotton comprises the following components: polypropylene, polyethylene terephthalate, EVA hot melt adhesive and decalin; Adding EVA hot melt adhesive to polypropylene to prepare a first spinning solution, adjusting the viscosity of the prepared first spinning solution to less than 50 Pa·s within a shear rate range of 1000 to 10000 1 / s, and melt-blowing the first spinning solution using a melt-blowing device (11) to obtain a first polymer fiber; Adding decalin to polyethylene terephthalate to prepare a second spinning solution, adjusting the viscosity of the prepared second spinning solution to less than 150 mPa·s within a shear rate range of 1000 to 10000 1 / s, and flash evaporating the second spinning solution using a flash evaporation device (111) to obtain a second polymer fiber; Under the traction of a fan (114), the first polymer fiber and the second polymer fiber are mixed evenly using a plurality of air nozzles (112), and then ejected through a spinneret to obtain fibers with an average fiber diameter of 0.8-1 μm and a normal fiber diameter distribution. The prepared fibers are then subjected to opening, vibrating cotton feeding, combing, web laying, glue spraying, drying and ironing operations to obtain nanofiber thermal insulation cotton.

2. A testing device for nanofiber thermal insulation cotton, the testing device is used to test the nanofiber thermal insulation cotton as claimed in claim 1, comprising a frame (1), characterized in that: A U-shaped bracket (2) is fixedly mounted on the middle of the top of the frame (1), and a circular groove (3) is opened on the top surface of the frame (1), a transposition disk (4) is movably sleeved inside the circular groove (3), a driving motor (1) is fixedly mounted on the bottom of the frame (1), the output shaft end of the driving motor (1) movably passes through the frame (1), and the output shaft end of the driving motor (1) is fixedly connected to the transposition disk (4), and two groups of thin film temperature sensors (5) are fixedly embedded on the top of the transposition disk (4); A detection drive assembly (6) is provided on both sides of the U-shaped bracket (2), and the two detection drive assemblies (6) are centrally symmetrically arranged about the axis of the transposition disk (4); a thermal conductivity test assembly (7) and a pressure test assembly (8) are respectively arranged at positions corresponding to the two detection drive assemblies (6) on the top of the transposition disk (4); the two detection drive assemblies (6) are linked to each other; the thermal conductivity test assembly (7) and the pressure test assembly (8) respectively form a thermal conductivity detection mechanism and a pressure detection mechanism with the detection drive assembly (6) at the corresponding position; and a wireless signal transmitter (10) is installed on the thermal conductivity test assembly (7) and the pressure test assembly (8).

3. A testing device for nanofiber thermal insulation cotton according to claim 2, characterized in that: The detection drive assembly (6) comprises a horizontal plate (61) fixed to the side of the U-shaped bracket (2) and two vertical plates (62) fixed to the inner top surface of the U-shaped bracket (2); a vertical shaft (63) is movably penetrated through one end of the horizontal plate (61) away from the U-shaped bracket (2); two limiting baffles (64) are fixedly sleeved on the outer peripheral surface of the top end of the vertical shaft (63) and are respectively in contact with the upper surface and the lower surface of the horizontal plate (61); and a linkage portion is provided between the vertical shafts (63) on the two detection drive assemblies (6).

4. The testing device for nanofiber thermal insulation cotton according to claim 3, characterized in that: The linkage part comprises a second drive motor fixedly mounted at the top center position of the U-shaped bracket (2); the end of the output shaft of the second drive motor movably passes through the U-shaped bracket (2); and the end of the output shaft of the second drive motor is fixedly connected to a driving wheel (67); and driven wheels (68) are fixedly sleeved at positions on the outer circumferences of the two vertical shafts (63) corresponding to the driving wheel (67); and the two driven wheels (68) are connected to the driving wheel (67) through a belt transmission.

5. The testing device for nanofiber thermal insulation cotton according to claim 3, characterized in that: The bottom end of the vertical shaft (63) is fixedly connected to a rotating disk (65), and an arc-shaped convex plate (66) is fixedly provided at the edge of the bottom end surface of the rotating disk (65). A thin film pressure sensor (617) is installed at the middle of the bottom of the arc-shaped convex plate (66) and at one end of the bottom end surface edge of the rotating disk (65) away from the arc-shaped convex plate (66).

6. The testing device for nanofiber thermal insulation cotton according to claim 3, characterized in that: A deflection unit is provided between the vertical plate (62) on the detection drive assembly (6) and the frame (1), the deflection unit comprising a side plate (615) fixedly arranged on the top of the frame (1) and a deflection rod (69) rotatably installed between the two vertical plates (62) via a bearing, and a deflection block (610) is fixedly sleeved on the outer peripheral surface of the deflection rod (69) at a position between the two vertical plates (62); The middle parts of both sides of the deflection block (610) are respectively fixedly connected with a swing rod (611) and a ball seat rod, and the ends of the ball seat rod are fixedly connected with a round ball (612). The outer peripheral surface of one end of the deflection rod (69) close to the side plate (615) is fixedly provided with a U-shaped rod (613), and the middle part of the U-shaped rod (613) is movably sleeved with a ring (614), and a spring (616) is fixedly connected between the ring (614) and the side plate (615).

7. A testing device for nanofiber thermal insulation cotton according to claim 6, characterized in that: The thermal conductivity test assembly (7) comprises an isolation cover (73) fixedly connected to the end of a swing rod (611) on a corresponding position detection drive assembly (6), a cylinder (72) is fixedly mounted at the center of the top of the inner cavity of the isolation cover (73), and a telescopic end of the cylinder (72) is fixedly connected to an electric heating plate (71).

8. The testing device for nanofiber thermal insulation cotton according to claim 6, characterized in that: The pressure test assembly (8) comprises a top plate (81) fixedly connected to the end of a swing rod (611) on a corresponding position detection drive assembly (6); a limit frame (82) is fixedly sleeved on the side of the top plate (81); a pressure plate (83) is arranged inside the cavity between the top plate (81) and the limit frame (82); corner plates (85) are fixedly arranged at the four corners of the top of the limit frame (82); and guide columns (84) are fixedly arranged at the four corners of the top of the pressure plate (83); The top end of the guide column (84) is movable and passes through the top plate (81) and the angle plate (85) at the corresponding position in sequence. A circular plate (86) is fixedly provided on the top end surface of the guide column (84). A second spring (87) is fixedly connected to the side surface of the guide column (84) between the angle plate (85) and the circular plate (86). A pressure portion is provided between the top plate (81) and the pressure plate (83). A second film pressure sensor (810) is installed at the bottom of the pressure plate (83).

9. A testing device for nanofiber thermal insulation cotton according to claim 8, characterized in that: The pressure-applying portion comprises a core shaft (88) which is horizontally rotatably mounted on a limit frame (82) via a bearing, two groups of cams (89) are fixedly sleeved on the peripheral side of the core shaft (88), each group having three cams, and the three cams (89) in each group are arranged in a sequentially reduced manner along the axial direction of the core shaft (88), and a third drive motor is fixedly mounted on one side of the limit frame (82), and the end of the output shaft of the third drive motor is fixedly connected to one end of the core shaft (88).

10. A testing device for nanofiber thermal insulation cotton according to claim 2, characterized in that: A cooling mechanism (9) is provided between the thermal conductivity test assembly and the pressure test assembly (8), the cooling mechanism (9) comprising an L-shaped bracket (91) fixed to the top of the frame (1), a hollow fan ring plate (92) being fixedly connected to the inner top end surface of the L-shaped bracket (91), a plurality of groups of air outlet slots (93) being provided on the bottom end surface of the fan ring plate (92), and an air pump (94) and a push switch (95) being installed on the top of the L-shaped bracket (91).

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