Preparation method of vacuum insulated panel core material

Abstract

The invention relates to the technical field of production of vacuum insulated panel core materials, in particular to a preparation method of a vacuum insulated panel core material, which comprises the following steps: cutting raw materials by using an airflow feeding type section cutting machine, opening and mixing filaments, carding to form a net, laying the net to form a felt, hot-pressing and shaping, and cutting. According to the preparation method provided by the invention, a dry process is adopted, so that severe hydraulic shearing and mechanical friction damage to fibers caused by wet pulping are avoided; the step of cutting off the raw materials is carried out by adopting the airflow feeding type section cutting machine, the to-be-cut ends of the glass fiber filaments are downwards suspended in a discharging cavity and are attached to structures such as a second feeding roller by utilizing airflow before cutting, cutting point drifting caused by curling and bending of the fibers is effectively avoided, and the cutting efficiency is improved by being matched with cutting of a cutting knife. The length of the short cut filaments is strictly controlled within a required range, the length distribution of the short cut filaments is concentrated, and the problem that the pore uniformity of the core material and the stability of the heat insulation performance of a final product are affected due to non-uniform length of the short cut fibers is solved.

Description

Technical Field

[0001] This invention relates to the field of vacuum insulation panel core material production technology, specifically a method for preparing vacuum insulation panel core material. Background Technology

[0002] Vacuum insulation panels (VIPs) are advanced, high-efficiency insulation materials. Their core component is the core material, which primarily supports the panel structure and effectively blocks heat radiation and conduction. The performance of the core material directly determines the insulation effect and service life of the VIP.

[0003] Traditional VIP core materials, especially glass fiber core materials, are mostly prepared using wet processes. A typical wet process involves pulping short glass fibers (usually 2-3 cm) in water, pulling them through a filter to form a wet mat, then drying them at high temperatures for an extended period before finally cutting them. This process has disadvantages such as high water consumption, high energy consumption, long production cycles, and significant environmental impact. Furthermore, the fibers are easily damaged during pulping in the wet process, resulting in shorter fibers that affect the mechanical strength and porosity of the final core material, and there are limitations in controlling the fiber diameter.

[0004] While dry processing technology has been applied in other nonwoven fabric fields, how to adapt it to the production of VIP core materials, which have extremely high requirements for pore structure, fiber diameter distribution, and thermal conductivity, and how to solve technical problems such as fiber dispersion uniformity, felt density control, and final product structural stability in dry processing technology are the directions that need to be broken through in this field.

[0005] Furthermore, in the existing manufacturing process, when glass fiber filaments are cut into segments using traditional cutting equipment, the glass fiber filaments are prone to curling and bending. When pushed towards the cutting edge, the glass fiber filaments are not cut in a uniform, straight state, resulting in uneven length of the chopped fibers and large length errors. This further affects the mechanical strength and pore uniformity of the core material, and ultimately affects the thermal insulation performance of VIP products. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a vacuum insulation panel core material to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution.

[0008] A method for preparing a vacuum insulation panel core material includes the following steps: S1. Raw material cutting: Glass fiber filaments are continuously fed into the feeding channel of the air-feeding cutting machine. The first air gap blows air downward to form a pressing airflow, so that the end of the glass fiber filament to be cut hangs downward in the discharge chamber. The filament is continuously cut by the cutting blade to obtain glass fiber short filaments with a length of 5-9cm. S2, Opening and Mixing: The glass fiber chopped filaments obtained in S1 are fed into an opening device for opening to obtain fluffy mixed fibers; S3, Carding into a web: The fluffy mixed fibers are fed into a carding machine and carded into a thin layer of fibers with consistent direction or in a web-like distribution; S4. Laying the fiber into a felt: The fiber thin layer combed out in S3 is cross-laid or parallel-laid until the predetermined areal density and thickness are achieved to form a fiber felt blank. S5. Hot pressing and shaping: The fiber felt blank is fed into a hot press and continuously hot-pressed for 30-180 seconds at a temperature of 160-220℃ and a pressure of 0.5-2.0MPa to form a core material blank. S6. Cutting and processing: After the core material blank is cooled, it is cut according to the required size and shape of the vacuum insulation board to obtain the final vacuum insulation board core material product.

[0009] Preferably, the bulk density of the fluffy mixed fiber obtained in S2 is 10-30 kg / m³; the areal density of the fiber thin layer obtained in S3 is 20-100 g / m²; and the areal density of the fiber felt blank obtained in S4 is 100-500 g / m², with a thickness of 5-30 mm.

[0010] Preferably, the pneumatic feeding type slicing machine includes a collection box, side frames, and a cutting blade. Side frames are fixed to both sides of the collection box. An upper base and a lower base are installed from top to bottom on one side of the collection box, and a feeding conveyor belt is provided on the other side. Side bases are installed on one side of the upper and lower bases. A first feeding roller is rotatably embedded below the upper base, and a second feeding roller is rotatably embedded on one side of the lower base. The first and second feeding rollers are arranged in a staggered manner. A drive mechanism is provided on one side frame for driving the first and second feeding rollers. Reverse operation; a feeding channel is formed between the bottom surface of the upper base, the outer peripheral surface of the first feeding roller, the top surface of the lower base, and the outer peripheral surface of the second feeding roller, and the downstream side of the feeding conveyor belt is connected to the feeding channel; a vertical cavity is formed between the side base and the upper base, and a discharge cavity is formed between the side base and the lower base; part of the second feeding roller is exposed in the discharge cavity; the cutting blade is installed in the vertical cavity and can reciprocate up and down, and the side of the lower base near the side base has a pressure-bearing boss that receives the cutting part of the cutting blade; an air supply system is provided on the upper base for introducing airflow into the vertical cavity.

[0011] Preferably, the air supply system includes an air inlet channel and an air supply pipe; an air inlet channel is provided in the upper base, the air inlet channel extends in an L-shape, one end is connected to the air supply pipe, and the other end is connected to the vertical cavity; the port where the air inlet channel connects to the vertical cavity is defined as the air inlet port; the end of the air supply pipe is connected to the air supply equipment.

[0012] Preferably, the cutting blade slides against the inner walls of the vertical cavity and the discharge cavity; the top of the cutting blade has a baffle portion, which is plate-shaped; both ends of the baffle portion slide against the inner walls of the vertical cavity respectively, and one side slides against the inner wall of the vertical cavity near the upper base; when the baffle portion is above the air inlet port, a first downward-opening air gap is formed between the side of the cutting blade near the upper base, the lower surface of the baffle portion, and the side wall of the vertical cavity; the airflow blows downward into the discharge cavity from the first air gap, forming a pressing airflow, so that the glass fiber filament to be cut hangs downward in the discharge cavity.

[0013] Preferably, when the cutting blade descends to the cutting section and abuts against the pressure-bearing protrusion to achieve cutting, the baffle section descends to below the air inlet port, and a second air-blowing gap with an opening facing downward is formed between the side of the cutting blade away from the upper base, the upper surface of the baffle section, and the inner wall of the vertical cavity; a downward-flowing airflow can be formed in the second air-blowing gap to blow the short shredded material that falls into the discharge chamber downstream.

[0014] Preferably, the thickness of the baffle is smaller than the diameter of the air inlet port; when the baffle moves to the same height as the axis of the air inlet port, there is a gap between the cutting part of the cutting blade and the pressure-bearing boss for airflow to pass through.

[0015] Preferably, the side base is L-shaped; the discharge cavity formed between the side base and the lower base is L-shaped; the end of the discharge cavity is connected to the inside of the collection box, and in conjunction with the blowing airflow, it can flatly blow the short shredded material into the collection box.

[0016] Preferably, two guide rods are vertically fixed to the top of the side base, and a lifting platform is slidably mounted on the two guide rods; two downward-facing sleeves are fixed to the lower surface of the lifting platform; two connecting rods are fixed to the top of the baffle, and the two connecting rods slide through and extend to the top of the side base, and are slidably inserted into the sleeves one by one; a spring is vertically installed in both sleeves, one end of the spring is fixed to the top wall of the sleeve, and the other end is fixed to the top of the connecting rod; a driving device is installed on one side frame to drive the lifting platform to move up and down, so as to realize the downward cutting and upward resetting action of the cutting blade; wherein, the driving device is configured to: after driving the cutting blade downward to the cutting end of the cutting blade abutting against the pressure boss, continue to drive the cutting blade downward a predetermined distance.

[0017] Preferably, the drive mechanism includes a drive motor, a first gear, and a second gear; one side shaft end of both the first and second feed rollers extends to the outside of the side frame, wherein the first gear is fixed on the shaft end of the first feed roller, and the second gear is fixed on the shaft end of the second feed roller, and the second gear meshes with the first gear; a motor base is fixed on the side frame, and the drive motor is fixed on the motor base; the output shaft of the drive motor is fixedly connected to the shaft end of the first feed roller.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows.

[0019] The preparation method provided by this invention adopts a dry process, which avoids the severe hydraulic shear and mechanical friction damage to fibers caused by wet pulping, so that the initial length and strength of the fibers can be better preserved. Moreover, no water is needed throughout the process, and no wastewater is generated, which reduces environmental pressure and sewage treatment costs. At the same time, it shortens the production cycle, reduces energy consumption, and reduces the equipment footprint and overall investment.

[0020] The preparation method provided by this invention uses an airflow feeding slitting machine to cut the raw materials. Before cutting, airflow is used to suspend the glass fiber filaments to be cut downwards in the discharge chamber and attach them to the second feeding roller and other structures. This effectively avoids the drift of the cutting point caused by the fiber curling and bending. Combined with the cutting blade, the length of the chopped filaments is strictly controlled within the required range, and the length distribution of the chopped filaments is concentrated. This solves the problem that the uneven length of the chopped fibers affects the uniformity of the core material pores and the stability of the thermal insulation performance of the final product.

[0021] This invention forms a seal when the cutting blade abuts against the pressure-bearing boss, creating a second air-blowing gap. This ensures that after the cutting action is completed, the cut short filaments can be quickly blown downstream, preventing the cut fibers from remaining in the discharge chamber and hooking with the ends of the long filaments to be cut. This avoids the risk of material blockage and abnormal secondary cutting caused by fiber entanglement, ensuring continuous, stable and efficient production.

[0022] This invention, through the design that the thickness of the baffle is less than the diameter of the air inlet, splits the airflow on both sides of the cutting blade to form an airflow, which can continuously press the fiber segment to be cut onto the second feeding roller and the inner wall of the discharge chamber. The airflow acts on the vicinity of the cutting point through the gap between the cutting blade and the pressure-bearing boss, and performs continuous airflow combing and stable positioning of the fiber before the cutting action, reducing the cutting length error caused by the slight slippage or shaking of the fiber, and further improving the cutting accuracy and consistency. Attached Figure Description

[0023] Figure 1 A flowchart illustrating the preparation method provided by this invention; Figure 2 This is one of the schematic diagrams of the airflow feeding type segment cutter used in this preparation method; Figure 3 for Figure 2 Another perspective view of the structure shown; Figure 4 This is a schematic diagram of a partial internal structure of the collection box; Figure 5 for Figure 1 The diagram shows a cross-sectional structure. Figure 6 This is a schematic diagram showing the structural distribution of the cutting blade and two feeding rollers in an airflow feeding type segment cutter. Figure 7 This is a schematic diagram showing the structure and installation of the cutting blade in an air-feeding segment cutter. Figure 8 This is a schematic diagram of the drive mechanism of an airflow feeding slicing machine; Figure 9 A schematic diagram of the structure that forms the first air-blowing gap during the operation of an air-feeding cutting machine; Figure 10 A schematic diagram of the structure that forms the second air-blowing gap during the operation of the cutting machine; Figure 11 This is a schematic diagram showing the airflow direction when the baffle is located in the middle of the air inlet.

[0024] In the diagram: 01, feeding channel; 02, first air blowing gap; 03, second air blowing gap; 1, collection box; 101, collection chamber; 102, support; 103, pneumatic conveying pipe; 11, side frame; 12, feeding conveyor belt; 2, upper base; 21, air inlet channel; 211, air inlet port; 22, air supply pipe; 3, lower base; 31, pressure-bearing boss; 4, side base; 401, guide rod; 41, vertical cavity; 42, discharge cavity; 5, first feeding roller; 6, second feeding roller; 7, cutting blade; 701, lifting platform; 71, flow-blocking part; 8, connecting rod; 81, sleeve; 82, spring; 9, drive mechanism; 91, motor base; 92, drive motor; 93, first gear; 94, second gear. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments: This invention is not limited to the specific embodiments listed below. Those skilled in the art can implement this invention using various other specific embodiments based on the content disclosed herein. Any modifications or alterations made to the design structure and concept of this invention fall within the protection scope of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0028] Please see Figures 1-11 This embodiment provides a method for preparing the core material of a vacuum insulation panel. The method uses an airflow feeding cutter as the raw material cutting equipment, and the specific steps are as follows: S1. Raw material cutting: Alkali-free glass fiber filaments with a nominal diameter of 9 micrometers are continuously fed into the feeding channel 01 of the air-feeding cutting machine. The first air-blowing gap 02 blows air downward to form a pressing airflow, causing the glass fiber filament to be cut to hang downward in the discharge chamber 42. The filament is continuously cut by the cutting blade 7 to obtain glass fiber short filaments with a length of 5-9cm. S2. Opening and Blending: Approximately 50 kg of chopped filaments are fed into the feeding bin of the licker-roller opener. The equipment is started, and the fibers are gradually opened and fluffy under the continuous tearing and combing of multiple licker-rollers. The density is approximately 20 kg / m³, and the opening process also achieves uniform mixing of the fibers. S3. Carding into web: After opening, the fibers are transported to the double cylinder double doffer roller carding machine through the airflow pipe. The fibers are finely carded by multiple carding rollers to remove some ultra-short fibers and form a continuous fiber web with high fiber orientation. The web is peeled off from the doffer and the output speed of the fiber web is controlled to keep the surface density of the single layer fiber web stable at about 50g / m². S4. Laying the web into felt: The combed fiber web enters the 90° cross-laying machine. The laying machine folds the fiber web back and forth and lays it on the conveyor curtain, laying about 20 layers to form a fiber felt blank with a surface density of about 400g / m² and a thickness of about 25mm. S5. Hot pressing and shaping: The fiber felt blank is fed into a flat hot press. The temperature of the upper and lower hot press plates is set to 185℃. The hot press plates are closed and a pressure of 1.2MPa is applied to the felt blank. The pressure is maintained for 100 seconds. During this process, the sizing agent on the fiber surface softens and melts when heated, forming a strong bonding point at the fiber intersection. This solidifies the fluffy felt blank into a blank with a certain strength and rigidity, and the thickness is compressed to about 15mm. Specifically, this involves using a thermoplastic polymer sizing agent (such as epoxy resin, polyvinyl acetate, etc.) coated on the surface of the glass fiber (approximately 0.5%-1.0% by weight). When the temperature rises above the softening point of the polymer, the mobility of the polymer chain segments increases, and the material becomes sticky. Under external pressure, the molten polymer at the contact points of adjacent fibers diffuses and entangles with each other. After pressure holding and cooling, strong bonding nodes are formed at these contact points, fixing the entire fiber network. This imparts a certain compressive strength and dimensional stability to the core material, preventing it from collapsing or deforming during subsequent VIP packaging, handling, and use. At the same time, it does not excessively fill or block the pores between fibers, thus maximizing the preservation of the porous structure. S6. Cutting process: After hot pressing, the slab is removed and cooled to room temperature. Then, a CNC cutting machine is used to cut it into core material sheets of the corresponding shape and size according to the subsequent processing requirements to obtain the final product.

[0029] It is evident that the dry process requires no water and generates no wastewater throughout the entire production process, completely eliminating the pulping and high-temperature drying steps of the wet process, significantly reducing energy consumption. Furthermore, the dry process has fewer steps, a shorter production cycle, and requires a relatively smaller equipment footprint, reducing investment and operating costs. It avoids the severe mechanical damage to fibers caused by wet pulping, better maintaining the initial length and strength of the fibers, which is conducive to forming a more stable fiber network skeleton. The core material formed by the dry process has a uniform and controllable pore structure.

[0030] Testing revealed that the core material prepared in this embodiment has a fiber length-weighted geometric mean diameter of 9.10 micrometers, which meets EU safety standards. In the subsequently manufactured VIP, the initial thermal conductivity can reach below 0.002 W / (m·K), demonstrating excellent thermal insulation performance. Example 2

[0031] Please see Figures 2-11 This embodiment provides a detailed description of the pneumatic feeding type cutting machine used in Embodiment 1, as follows: The pneumatic feeding type cutting machine includes a collection box 1, side frames 11, and cutting blades 7. Side frames 11 are fixed on both sides of the collection box 1. An upper base 2 and a lower base 3 are installed from top to bottom on one side of the collection box 1, and a feeding conveyor belt 12 is provided on the other side. A side base 4 is installed on one side of the upper base 2 and the lower base 3. A first feeding roller 5 is rotatably embedded below the upper base 2, and a second feeding roller 6 is rotatably embedded on one side of the lower base 3. The first feeding roller 5 and the second feeding roller 6 are arranged in a staggered manner. A drive mechanism 9 is provided on one side frame 11 to drive the first feeding roller 5 and the second feeding roller 6 to rotate in opposite directions. A feeding channel 01 is formed between the bottom surface of the upper base 2, the outer peripheral surface of the first feeding roller 5, the top surface of the lower base 3, and the outer peripheral surface of the second feeding roller 6. The downstream side of the feeding conveyor belt 12 is connected to the feeding channel 01, and the feeding conveyor belt 12 is used to transport raw materials into the feeding channel 01.

[0032] A vertical cavity 41 is formed between the side base 4 and the upper base 2, and a discharge cavity 42 is formed between the side base 4 and the lower base 3. The second feeding roller 6 is partially exposed in the discharge cavity 42. The cutting blade 7 is installed in the vertical cavity 41 and can reciprocate up and down. The side of the lower base 3 near the side base 4 has a pressure-bearing boss 31 that receives the cutting part of the cutting blade 7. An air supply system is provided on the upper base 2 to introduce airflow into the vertical cavity 41.

[0033] like Figure 6 As shown, the air supply system includes an air inlet channel 21 and an air supply pipe 22. The air inlet channel 21 is provided in the upper base 2. The air inlet channel 21 extends in an L-shape, with one end connected to the air supply pipe 22 and the other end connected to the vertical cavity 41. The port where the air inlet channel 21 connects to the vertical cavity 41 is defined as the air inlet port 211. The end of the air supply pipe 22 is connected to the air supply equipment (using existing technology, not shown in the figure). The air supply equipment introduces airflow into the air supply pipe 22. The airflow can flow into the vertical cavity 41 through the air inlet channel 21 and the air inlet port 211, forming a working airflow that flows downward into the discharge cavity 42.

[0034] The cutting blade 7 slides against the inner walls of the vertical cavity 41 and the discharge cavity 42. The top of the cutting blade 7 has a baffle 71, which is plate-shaped. Both ends of the baffle 71 slide against the inner walls of the vertical cavity 41, and one side slides against the inner wall of the vertical cavity 41 near the upper base 2. When the baffle 71 is above the air inlet port 211, a first downward-opening air gap 02 is formed between the side of the cutting blade 7 near the upper base 2, the lower surface of the baffle 71, and the side wall of the vertical cavity 41. The airflow blows downward into the discharge cavity 42 from the first air gap 02, forming a pressing airflow so that the glass fiber filament to be cut hangs downward in the discharge cavity 42.

[0035] Furthermore, when the cutting blade 7 descends to the cutting section and abuts against the pressure-bearing boss 31 to perform cutting, the baffle 71 descends to below the air inlet port 211. A second air-blowing gap 03 with an opening facing downward is formed between the side of the cutting blade 7 away from the upper base 2, the upper surface of the baffle 71, and the inner wall of the vertical cavity 41. A downward-flowing airflow can be formed in the second air-blowing gap 03 to blow the short shredded material that falls into the discharge cavity 42 downstream.

[0036] like Figure 8 As shown, the drive mechanism 9 includes a drive motor 92, a first gear 93, and a second gear 94. One side shaft end of the first feeding roller 5 and the second feeding roller 6 both extend to the outside of the side frame 11. The first gear 93 is fixed on the shaft end of the first feeding roller 5, and the second gear 94 is fixed on the shaft end of the second feeding roller 6. The second gear 94 meshes with the first gear 93. A motor base 91 is fixed on the side frame 11, and the drive motor 92 is fixed on the motor base 91. The output shaft of the drive motor 92 is fixedly connected to the shaft end of the first feeding roller 5. When the drive motor 92 is working, its output shaft can drive the first feeding roller 5 to rotate. Under the meshing transmission action of the first gear 93 and the second gear 94, the first feeding roller 5 can drive the second feeding roller 6 to rotate in the opposite direction. Thus, the first feeding roller 5 and the second feeding roller 6 can rotate and work simultaneously and share the same drive source.

[0037] The specific working principle of this embodiment is as follows: Multiple strands of glass fiber filaments are placed on the feeding conveyor belt 12 and straightened to ensure that the glass fiber filaments extend along the conveying direction of the feeding conveyor belt 12. The feeding conveyor belt 12 first conveys the glass fiber filaments to the space between the first feeding roller 5 and the lower base 3. The drive mechanism 9 starts working and drives the first feeding roller 5 to rotate counterclockwise. At the same time, it drives the second feeding roller 6 to rotate clockwise. The rotating first feeding roller 5 and the second feeding roller 6 can convey the glass fiber filaments downstream in the feeding channel 01 until the glass fiber filaments to be cut extend into the discharge cavity 42 to reach the predetermined length. Then the drive mechanism 9 stops working. like Figure 9 As shown (arrows in the figure indicate the direction of airflow), the cutting blade 7 is initially in an upward reset state. A first air-blowing gap 02 is formed on the side of the cutting blade 7 near the upper base 2. The airflow supplied by the air supply system into the vertical cavity 41 flows directly into the first air-blowing gap 02, forming a pressing airflow that flows downward into the discharge cavity 42. This pressing airflow can blow the portion of the glass fiber filament to be cut into the discharge cavity 42 and adhere it to the outer wall of the second feeding roller 6 and the inner wall of the discharge cavity 42 (e.g., ...). Figure 9As shown by the bold line in the figure (where, for simplicity, only a single glass fiber filament is shown in the figure), the end of the glass fiber filament to be cut is approximately suspended in the discharge cavity 42, which in turn plays a combing role on the end of the glass fiber filament, avoiding the curling and bending of the glass fiber end to be cut, which would lead to a large error in the cutting length. Subsequently, as Figure 10 As shown (the arrows in the figure indicate the direction of airflow), the cutting blade 7 is controlled to move downward until the cutting part at the bottom of the cutting blade 7 contacts the pressure-bearing boss 31, which can cut off the corresponding length of the glass fiber filament. The cut material falls into the discharge chamber 42. At the same time, the baffle part 71 on the cutting blade 7 moves downward to below the air inlet port 211 and forms a second air blowing gap 03 in the vertical chamber 41. The supplied airflow only flows into the second air blowing gap 03, forming a blowing airflow that flows downward into the discharge chamber 42, which can continuously transport the cut material that falls into the discharge chamber 42 downstream. Among them, such as Figure 10 As shown, when the cutting part at the bottom of the cutting blade 7 abuts against the pressure-bearing boss 31, a sealing and blocking structure is formed. On the one hand, it prevents the broken material from getting tangled and hooked with the end of the glass fiber filament and unable to be discharged normally, thus preventing it from being cut again. On the other hand, it ensures that the airflow in the second air gap 03 will not leak to the other side of the cutting blade 7 and maintains the required air pressure, thereby preventing the broken material from accumulating in the discharge chamber 42 due to insufficient air pressure and causing blockage.

[0038] In addition, the sealing and blocking structure formed by the bottom cutting part of the cutter 7 abutting against the pressure-bearing boss 31 can also prevent the airflow in the second air gap 03 from leaking to the side of the cutter 7 near the lower base 3 and forming turbulence, which would cause the ends of the glass fiber filaments to be excessively curled and hooked.

[0039] After the first section is cut, the cutting blade 7 moves upward until the baffle 71 moves above the air inlet port 211. At this point, the first air gap 02 is formed again between the cutting blade 7 and the inner wall of the vertical cavity 41. The drive mechanism 9 then drives the first feeding roller 5 and the second feeding roller 6 to rotate and feed the end of the glass fiber filament into the discharge cavity 42 to a predetermined length. The pressure airflow formed in the first air gap 02 blows the end of the glass fiber filament into the discharge cavity 42 to adhere to the outer wall of the second feeding roller 6 and the inner wall of the discharge cavity 42. The above cutting action is repeated, and so on, so that the glass fiber filament can be continuously cut into glass fiber short filaments of 5-9 cm in length.

[0040] In addition, such as Figure 3 and Figure 4As shown, the bottom of the collection box 1 has a collection chamber 101. The glass fiber chopped strands in the collection box 1 eventually fall into the collection chamber 101. The side of the collection box 1 is equipped with a pneumatic conveying pipe 103 through a bracket 102. One end of the pneumatic conveying pipe 103 is connected to the collection chamber 101, and the other end is connected to the subsequent process. The glass fiber chopped strands that fall into the collection chamber 101 can be continuously and stably conveyed to the subsequent process through the pneumatic conveying pipe 103.

[0041] The airflow entering the collection box 1 from the discharge chamber 42 will eventually flow into the pneumatic conveying pipe 103, complementing the original conveying airflow in the pneumatic conveying pipe 103, improving the capture efficiency of glass fiber chopped filaments, avoiding excessive accumulation and residue of chopped filaments in the collection chamber 101, and ensuring the continuous smoothness of the conveying process. Example 3

[0042] Please see Figure 11 (The arrows in the diagram indicate the direction of airflow.) The difference between this embodiment and Embodiment 2 is that: The thickness of the baffle 71 is less than the diameter of the air inlet port 211. When the baffle 71 moves to the same height as the axis of the air inlet port 211, there is a gap between the cutting part of the cutting blade 7 and the pressure-bearing boss 31 for airflow to pass through (at this time, the cutting blade 7 is not pressed against the glass fiber filament). Therefore, the airflow entering the vertical cavity 41 from the air inlet port 211 can be divided into two streams and flow downward from both sides of the cutting blade 7.

[0043] The airflow near the upper base 2 continuously blows the glass fiber filaments onto the second feeding roller 6, and finally flows into the other side through the gap between the cutting part of the cutting blade 7 and the pressure boss 31. This blows the glass fiber filaments to be cut onto the pressure boss 31, ensuring stability during cutting. Meanwhile, the airflow near the side base 4 continuously blows the ends of the glass fiber filaments onto the inner wall of the discharge chamber 42. When the cutting part of the cutting blade 7 presses against the glass fiber filaments until it comes into contact with the pressure boss 31, it can limit the excessive movement of the glass fiber filaments when the airflow fluctuates. Thus, the above mechanism can ensure that the glass fiber filaments remain suspended (combed) in the discharge chamber 42 before being cut, ensuring stability during cutting. Example 4

[0044] like Figure 10 As shown (the arrows in the figure indicate the direction of airflow), the difference between this embodiment and Embodiment 3 is: The side base 4 is L-shaped, and the discharge cavity 42 formed between the side base 4 and the lower base 3 is also L-shaped. The end of the discharge cavity 42 connects to the inside of the collection box 1. The blowing airflow and the material flow change direction (from vertical to horizontal) when they reach the bottom of the discharge cavity 42. Figure 10As shown, the blowing airflow horizontally blows the broken material, and finally the broken material is thrown into the collection box 1. This process disperses the clustered broken material and distributes it evenly, reducing the pressure of subsequent pneumatic conveying and reducing the pressure load of subsequent opening and mixing steps. Example 5

[0045] Please see Figure 3 and Figure 7 Based on the aforementioned embodiments, this embodiment provides a detailed description of the installation method of the cutting blade 7, as follows: Specifically, two guide rods 401 are vertically fixed to the top of the side base 4. A lifting platform 701 is slidably mounted on the two guide rods 401. Two downward-facing sleeves 81 are fixed to the lower surface of the lifting platform 701. Two connecting rods 8 are fixed to the top of the baffle 71. The two connecting rods 8 slide through and extend to the top of the side base 4, and are slidably inserted into the sleeves 81 one by one. Springs 82 are vertically installed in both sleeves 81. One end of the spring 82 is fixed to the inner top wall of the sleeve 81, and the other end is fixed to the top of the connecting rod 8. A driving device is installed on one side frame 11. The driving device adopts existing technology and is not shown in the figure. The driving device is connected to the lifting platform 701 and is used to drive the lifting platform 701 to move up and down, so as to realize the downward cutting and upward resetting action of the cutting blade 7. The driving device is configured to continue to drive the cutting blade 7 to move down a predetermined distance after the cutting end of the cutting blade 7 contacts the pressure boss 31.

[0046] When the drive device drives the lifting platform 701 and the cutting blade 7 to descend as a whole until the cutting end of the cutting blade 7 contacts the pressure-bearing boss 31, the drive device continues to drive the cutting blade 7 to descend a predetermined distance. At this time, the cutting blade 7, the baffle 71 and the connecting rod 8 move upward relative to the sleeve 81. At the same time, the spring 82 is compressed and stores energy. After the cutting blade 7 moves upward, due to the elastic restoring effect of the spring 82, the cutting blade 7 can be pushed to continue to contact the pressure-bearing boss 31. This mechanism plays a buffering role in the contact and cutting process between the cutting blade 7 and the pressure-bearing boss 31, avoiding damage to the blade. In addition, after the cutting action is completed, the state in which the cutting part of the cutting blade 7 contacts the pressure-bearing boss 31 to form a second air gap 03 can still be maintained for a period of time. Thus, it ensures that the airflow continuously and stably blows the cut material downstream, preventing the material from being excessively retained or rebounding. Example 6

[0047] The length of the chopped glass fiber filaments after being cut by the pneumatic feeding slitting machine during the raw material cutting step was sampled and measured, as follows: Using a random multi-point sampling method, after the equipment ran continuously for 10 minutes, 100g of the cut glass fiber shreds were taken as samples at the 5th, 10th, 15th, 20th, 25th and 30th minutes, for a total of 6 samples. For each sample, 50 shreds were randomly selected (outliers smaller than 4cm or larger than 10cm were removed, and no more than 3 shreds were removed from each sample). Using a measuring tool with an accuracy of 0.1mm, the shreds were laid flat and straightened (avoiding stretching) and the straight-line distance between the two ends was measured and recorded. Measurement results show that the length of the 300 effective chopped filaments is concentrated between 5.2cm and 8.8cm, with 72 filaments (24%) in the 5.0-6.0cm range, 126 filaments (42%) in the 6.0-7.0cm range, 84 filaments (28%) in the 7.0-8.0cm range, and 18 filaments (6%) in the 8.0-9.0cm range. The length-weighted average is 6.75cm, and the standard deviation is 0.82cm. It can be seen that when using this air-feed cutting machine for raw material cutting, the glass fiber chopped filaments obtained have a uniform length distribution and a high dimensional yield.

[0048] It is worth noting that the present invention provides a method for preparing the core material of a vacuum insulation panel. This method uses an air-feeding cutting machine to cut the raw materials. The method of using the air-feeding cutting machine (working principle) is also part of this preparation method. Therefore, the specific structure and method of using the air-feeding cutting machine are included within the protection scope of the present invention.

[0049] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Therefore, the present invention will not explain the control method and circuit connection in detail.

[0050] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. A method for producing a vacuum insulating panel core material, characterized by, The preparation method comprises the following steps: S1, raw material cutting: continuously send the glass fiber filament into the feeding channel (01) of the air flow feeding type cutting machine, blow air downward in the first air blowing gap (02) to form a pressure feeding air flow, make the to-be-cut end of the glass fiber filament hang downward in the discharge cavity (42), continuously cut the filament by using the cutting knife (7), and obtain glass fiber chopped filament with a length of 5-9 cm; S2, opening and mixing: send the glass fiber chopped filament obtained in S1 into the opening equipment to open and mix, and obtain fluffy mixed fibers; S3, carding into a web: send the fluffy mixed fibers into a carding machine, and card into a fibrous layer with consistent direction or in a net-like distribution; S4, laying into a mat: cross-lay or parallel-lay the fibrous layer carded in S3 until the predetermined area density and thickness are reached, and form a fibrous mat blank; S5, hot pressing and shaping: send the fibrous mat blank into a hot press, continuously hot press at a temperature of 160-220 DEG C and a pressure of 0.5-2.0 MPa for 30-180 seconds, and form a core material blank; S6, cutting processing: after the core material blank is cooled, cutting is performed according to the size and shape required by the vacuum heat insulation board, and the final vacuum heat insulation board core material product is obtained.

2. The preparation method of the vacuum heat insulation board core material according to claim 1, wherein: the fluffy density of the fluffy mixed fibers obtained in S2 is 10-30 kg / m³; the area density of the fibrous layer obtained in S3 is 20-100 g / m²; the area density of the fibrous mat blank obtained in S4 is 100-500 g / m², and the thickness is 5-30 mm.

3. The preparation method of the vacuum heat insulation board core material according to claim 1, wherein: the air flow feeding type cutting machine comprises a collecting box (1), a side frame (11) and a cutting knife (7), and the collecting box (1) is fixed with the side frame (11) on both sides; an upper base (2) and a lower base (3) are installed on one side of the collecting box (1) from top to bottom, a feeding conveyor belt (12) is arranged on the other side, and a side base (4) is installed on one side of the upper base (2) and the lower base (3); a first feeding roller (5) is rotatably embedded below the upper base (2), a second feeding roller (6) is rotatably embedded on one side of the upper base (3), and the first feeding roller (5) and the second feeding roller (6) are arranged in a staggered manner, and a driving mechanism (9) is arranged on one side of the side frame (11) to drive the first feeding roller (5) and the second feeding roller (6) to operate in opposite directions; a feeding channel (01) is formed between the bottom surface of the upper base (2), the outer peripheral surface of the first feeding roller (5), the top surface of the lower base (3) and the outer peripheral surface of the second feeding roller (6), and the downstream side of the feeding conveyor belt (12) is connected with the feeding channel (01); a vertical cavity (41) is formed between the side base (4) and the upper base (2), and a discharge cavity (42) is formed between the side base (4) and the lower base (3); the second feeding roller (6) is partially exposed in the discharge cavity (42). The cutting knife (7) is installed in the vertical cavity (41) and can reciprocatingly ascend and descend, and the lower base (3) is provided with a pressure bearing boss (31) on the side close to the side base (4) and abutting the cutting part of the cutting knife (7); The upper base (2) is provided with a gas supply system for supplying gas flow into the vertical cavity (41).

4. The method according to claim 3, wherein: The gas supply system comprises an air inlet channel (21) and an air supply pipe (22); The air inlet channel (21) is L-shaped and extends, one end of which is communicated with the air supply pipe (22) and the other end is communicated with the vertical cavity (41); The port of the air inlet channel (21) communicated with the vertical cavity (41) is defined as an air inlet port (211); The air supply pipe (22) is communicated with the air supply device at the end.

5. The method according to claim 4, wherein: The cutting knife (7) is slidably fitted with the inner wall of the vertical cavity (41) and the material discharge cavity (42); The cutting knife (7) is provided with a flow blocking part (71) at the top, which is plate-shaped; The flow blocking part (71) is slidably fitted with the inner wall of the vertical cavity (41) at both ends and the inner wall of the vertical cavity (41) close to the upper base (2) at one side; When the flow blocking part (71) is above the air inlet port (211), the first downward blowing gap (02) is formed between the side of the cutting knife (7) close to the upper base (2), the lower surface of the flow blocking part (71) and the side wall of the vertical cavity (41); The gas flow is blown downward from the first blowing gap (02) into the material discharge cavity (42) to form a pressure material flow, so that the to-be-cut end of the glass fiber filament is suspended downward in the material discharge cavity (42).

6. The method according to claim 5, wherein: When the cutting knife (7) is lowered to the cutting part to abut on the pressure bearing boss (31) to realize cutting, the flow blocking part (71) is lowered to below the air inlet port (211), and the second downward blowing gap (03) is formed between the side of the cutting knife (7) away from the upper base (2), the upper surface of the flow blocking part (71) and the inner wall of the vertical cavity (41); The second blowing gap (03) can form a downward blowing material flow to blow the cut short filaments falling into the material discharge cavity (42) downstream.

7. The method according to claim 5, wherein: The thickness of the flow blocking part (71) is less than the diameter of the air inlet port (211); When the flow blocking part (71) is moved to the same height as the axis of the air inlet port (211), there is a gap for gas flow between the cutting part of the cutting knife (7) and the pressure bearing boss (31).

8. The method according to claim 3, wherein: The side base (4) is L-shaped. The discharge cavity (42) formed between the side base (4) and the lower base (3) is L-shaped; The end of the discharge cavity (42) is connected with the inside of the collecting box (1), and the short cut yarns can be blown and sent to the collecting box (1) by cooperating with the blowing airflow. 9.The method of claim 5, wherein: Two guide rods (401) are vertically fixed on the top of the side base (4), and a lifting frame (701) is slidably sleeved on the two guide rods (401); Two sleeve (81) are fixed on the lower surface of the lifting frame (701) and open downward; Two connecting rods (8) are fixed on the top of the flow blocking part (71), and the two connecting rods (8) extend to the upper side of the side base (4) and are slidably inserted into the sleeve (81) one by one; A spring (82) is vertically arranged in each of the two sleeve (81), one end of the spring (82) is fixed to the inner top wall of the sleeve (81), and the other end is fixed to the top of the connecting rod (8); A driving device is arranged on one side of the side frame (11) for driving the lifting frame (701) to ascend and descend, so as to realize the downward cutting and upward resetting of the cutting knife (7); The driving device is configured to continue driving the cutting knife (7) to descend by a predetermined distance after the cutting end of the cutting knife (7) contacts the pressure bearing boss (31). 10.The method of claim 3, wherein: The driving mechanism (9) comprises a driving motor (92), a first gear (93) and a second gear (94); One side of the shaft end of the first feeding roller (5) and the second feeding roller (6) extends to the outside of the side frame (11), wherein the first gear (93) is fixed on the shaft end of the first feeding roller (5), the second gear (94) is fixed on the shaft end of the second feeding roller (6), and the second gear (94) and the first gear (93) are engaged correspondingly; The motor seat (91) is fixed on the side frame (11), and the driving motor (92) is fixed on the motor seat (91); The output shaft of the driving motor (92) is fixedly connected with the shaft end of the first feeding roller (5).

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