A multi-stage pressing method for honeycomb fireproof and thermal insulation materials

Abstract

This invention discloses a multi-stage pressing method for honeycomb fireproof and thermal insulation materials. It employs segmented pressing, where multiple sets of multiple pairs of progressively lowering first pressing rollers in the first pressing stage are used to press the finished fireproof and thermal insulation material into the honeycomb core little by little. This avoids the problem of crushing or collapsing the softer honeycomb core, such as kraft paper, in a single pressing operation as described in CN107718843A. The second pressing stage uses at least one set of second pressing rollers with softer buffer sleeves to further press the finished fireproof and thermal insulation material so that both its upper and lower surfaces are lower than the honeycomb core, facilitating subsequent lamination with skins, fireproof boards, carbon fiber boards, cardboard, and other panels.

Description

Technical Field

[0001] This invention relates to the production process of honeycomb composite materials, and more specifically to a multi-stage pressing method for honeycomb fireproof and heat-insulating materials. Background Technology

[0002] Honeycomb sandwich structures are widely used in aerospace, packaging, and building insulation due to their advantages such as high specific strength and light weight. Among them, honeycomb cores made of aramid and aluminum are often used in high-end fields such as aerospace because of their high strength and good heat resistance; while honeycomb paper cores made of kraft paper have great application potential in the civilian market such as packaging, furniture, and building interior partitions because of their low cost, environmental friendliness, and wide availability.

[0003] In the manufacturing of honeycomb composite materials, the pressing and filling of fire-retardant and heat-insulating materials (such as foamed phenolic resin) into the honeycomb core cells is a key process for improving the overall integrity and functionality of the material. Patent document CN107718843A provides a highly efficient pressing device and method, such as... Figure 1 As shown, the fireproof and heat-insulating material 4, placed on the upper layer, is directly pressed into the honeycomb core 1 in the lower layer by several pairs of upper and lower pressing rollers 5. This technical solution is highly effective for honeycomb cores with high rigidity (such as aramid honeycomb and aluminum honeycomb), and can achieve one-time pressing. The process is simple and suitable for mass production. (In the figure, 6 is the honeycomb fireproof and heat-insulating material after pressing and composite, 7 is the induction mold, 10 is the buffer sleeve, 11 is the front and rear conveying device, and 12 is the pressing and positioning roller).

[0004] However, this single-compaction process faces significant technical obstacles when applied to flexible honeycomb cores such as kraft paper. The mechanical properties of honeycomb paperboard in the thickness direction mainly rely on the support provided by the regular hexagonal structure of the honeycomb core. Under vertical pressure, the cell walls (i.e., core strips) of honeycomb core 1 mainly bear compressive stress, and its instability usually manifests as buckling of the cell walls or failure of the adhesive joints. Studies have shown that when the vertical pressure exceeds the critical instability crushing load of honeycomb core 1, the edges of honeycomb core 1 will bend outward, leading to delamination of the adhesive surface and even irreversible collapse of the entire cell structure. Kraft paper substrate has limited ring crush strength and stiffness. Using a high-pressure process with single-compaction, the honeycomb core 1 is prone to being subjected to excessive pressure instantaneously and directly crushed, making it impossible to achieve effective filling of fireproof and heat-insulating materials. Furthermore, because fireproof and heat-insulating materials such as foamed phenolic resin are somewhat brittle, and the rolling rollers are in line contact with them, the height difference in one rolling operation causes the foamed phenolic resin to be subjected to excessive shear force, which can easily lead to breakage between the part that enters the rolling rollers and the part that does not. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-stage pressing method for honeycomb fireproof and thermal insulation materials. By segmenting and pressing in multiple stages, the upper layer of fireproof and thermal insulation material can be pressed into the softer honeycomb core through multiple stages, which can avoid the honeycomb core from being crushed, deformed, or collapsed, and the finished fireproof and thermal insulation material will not break.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A multi-stage pressing method for a honeycomb fireproof and thermal insulation material employs a multi-stage pressing device. This device includes front and rear conveying devices and a first and second pressing section located between the front and rear conveying devices. The first pressing section includes multiple sets of pressing rollers arranged sequentially. Each roller set includes multiple pairs of first pressing rollers arranged sequentially, and each pair of first pressing rollers consists of a first upper pressing roller and a first lower pressing roller. The second pressing section includes at least one pair of second pressing rollers arranged sequentially after the first pressing section. Each pair of second pressing rollers consists of a second upper pressing roller and a second lower pressing roller. The first and second upper pressing rollers and the first and second lower pressing rollers are all fitted with buffer roller sleeves forming the pressing surface. The second upper and lower... The hardness of the buffer sleeve of the rolling roller is lower than that of the buffer sleeve of the first upper and lower rolling rollers; the height of the highest rolling surface of all the first lower rolling rollers and the second lower rolling rollers is the same as the height of the front and rear conveying devices; the height of the lowest rolling surface of the first upper rolling roller of the first group is designed to be lower than the total thickness of the fireproof insulation material and the honeycomb core after stacking by a height difference; the height of the lowest rolling surface of the remaining first upper rolling rollers is arranged to decrease step by step from front to back according to the height difference, and the height difference is set according to the safe height obtained by the rolling test of the honeycomb core; the height of the lowest rolling surface of all the second upper rolling rollers is the same as that of the last upper rolling roller. The multi-stage suppression method includes the following steps: A. The fireproof and heat-insulating material with the same thickness as the honeycomb core is stacked on the honeycomb core and conveyed to the first rolling section through the front conveying device; B. The fireproof and heat-insulating material is pressed sequentially by the first upper and lower rollers of each roller group in the first rolling section, and the fireproof and heat-insulating material is pressed into the honeycomb core in a step-like manner. The height of each press is achieved by the height difference until the fireproof and heat-insulating material is completely pressed into the honeycomb core, so that the upper and lower surfaces of the fireproof and heat-insulating material are flush with the honeycomb core, and then it is conveyed to the second rolling section. C. After being pressed by at least one pair of second rolling rollers in the second rolling section, and after the upper and lower surfaces of the finished fireproof and heat-insulating material are pressed into the honeycomb core by its buffer roller sleeve, it is output by the rear conveying device.

[0008] In step B, the height difference is 0.5~4mm.

[0009] The height of the lowest rolling surface of the second upper rolling roller is 1-4 mm lower than the height of the lowest rolling surface of the first upper rolling roller.

[0010] In the same pair of first and second rolling rollers, at least one roller is the driving roller, and the height position of the first and second upper rolling rollers can be adjusted.

[0011] The hardness of the buffer sleeves of the first upper and lower rollers in the last group of the plurality of roller groups is lower than that of the other groups.

[0012] The Shore hardness of the buffer sleeves of the first upper and lower rollers in the last group of the plurality of roller sets is 45-50, and the Shore strength of the buffer sleeves of the first upper and lower rollers in the remaining groups is 50-60.

[0013] The Shore strength of the buffer roller sleeves of the second upper and lower rolling rollers is 45-40.

[0014] Transition rollers are provided between adjacent first rolling rollers and between adjacent second rolling rollers.

[0015] The segmented compaction device for honeycomb fireproof and heat-insulating materials of the present invention has the following advantages: 1. This invention employs segmented pressing, that is, multiple sets of multiple pairs of progressively decreasing height first pressing rollers in the first pressing section perform multiple progressive pressing operations to gradually press the fireproof and heat-insulating material into the honeycomb core. This avoids the situation described in CN107718843A, where a single pressing operation would crush or collapse the softer honeycomb core, such as kraft paper. At the same time, it reduces shear force and prevents the protective insulation material from breaking. In the second pressing section, at least one set of second pressing rollers with softer buffer roller sleeves further presses the fireproof and heat-insulating material so that both its upper and lower surfaces are lower than the honeycomb core, which is beneficial for subsequent lamination with skin, fireproof board, carbon fiber board, cardboard, and other panels.

[0016] 2. The step-by-step decreasing height difference of the first upper rolling roller can be determined by conducting a rolling test on the honeycomb core. That is, the rolling test is carried out by gradually lowering the height of the first upper rolling roller until the honeycomb core bends or the fireproof insulation material cracks. The height of the first upper rolling roller at this time is recorded, and this height is the safe height. The height difference is less than the total thickness of the fireproof insulation material and the honeycomb core minus the safe height. That is, the height of the fireproof insulation material should be set to be less than this safe height each time it is pressed in.

[0017] 3. The number of roller sets in the first compaction section can be adjusted according to different total thicknesses and height differences each time.

[0018] 4. The number of pairs of the second rolling rollers can be designed according to the actual compression and rebound performance of the finished fireproof and heat-insulating material. Through one or more elastic rolling processes, the upper and lower surfaces are pressed down and kept a few millimeters below the upper and lower surfaces of the honeycomb core.

[0019] 5. The buffer sleeve of the last group of first pressing rollers is designed to be less hard than that of the other first pressing rollers. This is so that when the first pressing rollers of this group are about to contact the honeycomb core, the softer buffer sleeve can prevent the honeycomb core from being crushed or deformed. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the existing crushing mechanism; Figure 2 This is a schematic diagram of the structure of the multi-stage pressing device of the present invention; Figure 3 This is a schematic diagram of the first set of compaction principles in the first compaction section of Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the second set of compaction principles in the first compaction section of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the third set of compaction principles in the first compaction section of Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the compaction principle of the second compaction section in Embodiment 1 of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0022] Example 1 The multi-stage pressing method for the honeycomb fireproof and heat-insulating material of the present invention employs, as follows: Figures 2-6 The multi-stage pressing device shown includes front and rear conveying devices 11 and a first pressing section 100 and a second pressing section 200 located between the front and rear conveying devices 11. The first pressing section 100 includes three sets of pressing rollers 110, 120, and 130 arranged sequentially. Each roller set includes five pairs of first pressing rollers arranged sequentially, and each pair of first pressing rollers consists of a first upper pressing roller 5a and a first lower pressing roller 5b. The second pressing section 200 includes three pairs of second pressing rollers arranged sequentially after the first pressing section 100, and each pair of second pressing rollers consists of a second upper pressing roller 9a and a second lower pressing roller 9b. The first and second upper rollers 5a and 9a, and the first and second lower rollers 5b and 9b are all fitted with buffer roller sleeves to form the rolling surface. The Shore hardness of the buffer roller sleeve 10a of the first two sets of first rollers is 60, and the Shore hardness of the buffer roller sleeve 10b of the third set of first rollers is 55. The Shore hardness of the buffer roller sleeve 10c of the second roller is 43.

[0023] The adjacent first rolling rollers and adjacent second rolling rollers are evenly spaced, and each is also equipped with a transition roller 8. The height of the highest rolling surface of all the first lower rolling rollers 5b and second lower rolling rollers 9b is the same as the height of the transition roller 8 and the front and rear conveying devices 11. In this embodiment, the thickness of the finished fireproof and heat-insulating material and the honeycomb core being rolled is 3cm, and the total thickness (height) of the two stacked on the front conveying device is 6cm. Therefore, the height of the lowest rolling surface of the first upper rolling roller 5a of the first roller group (i.e., the distance between the highest rolling surface of the first lower rolling roller 5b of the same pair) is set to 5.8cm, which is h1=2mm lower than the stacking height. The height of the lowest rolling surface of the subsequent first upper rolling rollers 5a is arranged to decrease stepwise from front to back with a height difference of h1=2mm, so as to form a stepped descent from front to back, until the height of the lowest rolling surface of the last first upper rolling roller 5a of the third roller group is exactly 3cm. In other words, each rolling action will press the fireproof and heat-insulating material 4 into the honeycomb core by 12mm without bending or deformation. The height of the lowest rolling surface of the three second upper rolling rollers 9a in the second rolling section 200 is the same and 3mm lower than the height of the lowest rolling surface of the last first upper rolling roller 5a in the third group. Thus, through the three rolling actions of the second rolling section 200, the upper and lower surfaces of the fireproof and heat-insulating material 4 can be pressed into the honeycomb core 1 by h2=1.5mm respectively and kept in shape without rebound.

[0024] This multi-stage suppression method specifically includes the following steps: A. The finished fireproof and heat-insulating material with a thickness of 3cm is stacked on the honeycomb core of the same thickness (the total stacking thickness is 6cm), and then conveyed to the first rolling section 100 through the front conveying device. B. The fireproof and heat-insulating material is pressed sequentially by the first upper and lower rollers of each roller group in the first rolling section 100, pressing the fireproof and heat-insulating material into the honeycomb core in a step-like manner. The height of each press is 2mm. Each group is pressed five times, that is, after each group is pressed, the fireproof and heat-insulating material is pressed into the honeycomb core by 1cm. After three groups of rolling, the fireproof and heat-insulating material is completely pressed into the honeycomb core, so that the upper and lower surfaces of the fireproof and heat-insulating material are flush with the honeycomb core, forming a composite material with a thickness of 3cm, and then conveyed to the second rolling section 200. C. After being pressed by the three pairs of second rolling rollers in the second rolling section 200, and further pressed into the upper and lower surfaces of the finished fireproof and heat-insulating material by its buffer roller sleeve to be 1.5mm lower than the upper and lower surfaces of the honeycomb core, it is output by the rear conveying device.

[0025] Example 2 The difference from Example 1 is that the thickness of the fireproof and heat-insulating material and the honeycomb core is 4cm. Therefore, the number of rolling rollers in the first rolling section 100 is increased to four. Through the four rollers in the first rolling section 100, a total of twenty step-by-step rollings are performed to completely press the fireproof and heat-insulating material into the honeycomb core. The rest remains unchanged.

[0026] Example 3 The difference from Example 1 is that the honeycomb core used has a lower hardness. Therefore, by adjusting and lowering the height of the first upper rolling roller, the height difference of the first rolling section 100 is reduced to 1mm, and the number of pairs of the first rolling rollers in each group is increased to ten pairs. In this way, each group can also press the fireproof and heat-insulating material into the ground by 1cm and ensure that the honeycomb core does not deform, while the rest remains unchanged.

[0027] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A multi-stage pressing method for a honeycomb fireproof and thermal insulation material, characterized in that: A multi-stage pressing device is employed, comprising front and rear conveying devices, and a first and second pressing section located between the front and rear conveying devices. The first pressing section includes multiple sets of pressing rollers arranged sequentially, each set including multiple pairs of first pressing rollers arranged sequentially, each pair consisting of a first upper pressing roller and a first lower pressing roller. The second pressing section includes at least one pair of second pressing rollers arranged sequentially after the first pressing section, each pair consisting of a second upper pressing roller and a second lower pressing roller. The first and second upper pressing rollers and the first and second lower pressing rollers are all fitted with buffer roller sleeves forming the pressing surface, and the hardness of the buffer roller sleeves of the second upper and lower pressing rollers is... The hardness is lower than that of the buffer roller sleeves of the first upper and lower rollers; the height of the highest rolling surface of all the first lower rollers and the second lower rollers is the same as the height of the front and rear conveying devices; the height of the lowest rolling surface of the first upper roller of the first group is designed to be lower than the total thickness of the fireproof insulation material and the honeycomb core after stacking by a height difference; the height of the lowest rolling surface of the remaining first upper rollers is arranged to decrease step by step from front to back according to the height difference, and the height difference is set according to the safe height obtained by the honeycomb core being rolled; the height of the lowest rolling surface of all the second upper rollers is the same as that of the last upper roller. The multi-stage suppression method includes the following steps: A. The fireproof and heat-insulating material with the same thickness as the honeycomb core is stacked on the honeycomb core and conveyed to the first rolling section through the front conveying device; B. The fireproof and heat-insulating material is pressed sequentially by the first upper and lower rollers of each roller group in the first rolling section, and the fireproof and heat-insulating material is pressed into the honeycomb core in a step-like manner. The height of each press is achieved by the height difference until the fireproof and heat-insulating material is completely pressed into the honeycomb core, so that the upper and lower surfaces of the fireproof and heat-insulating material are flush with the honeycomb core, and then it is conveyed to the second rolling section. C. After being pressed by at least one pair of second rolling rollers in the second rolling section, and after the upper and lower surfaces of the finished fireproof and heat-insulating material are pressed into the honeycomb core by its buffer roller sleeve, it is output by the rear conveying device.

2. The multi-stage pressing method for honeycomb fireproof and thermal insulation material as described in claim 1, characterized in that: In step B, the height difference is 0.5~4mm.

3. The multi-stage pressing method for honeycomb fireproof and thermal insulation material as described in claim 1, characterized in that: The height of the lowest rolling surface of the second upper rolling roller is 1-4 mm lower than the height of the lowest rolling surface of the first upper rolling roller.

4. The multi-stage pressing method for honeycomb fireproof and thermal insulation material as described in claim 1, characterized in that, In the same pair of first and second rolling rollers, at least one roller is the driving roller, and the height position of the first and second upper rolling rollers can be adjusted.

5. The multi-stage pressing method for honeycomb fireproof and heat-insulating materials as described in claim 1, characterized in that, The hardness of the buffer sleeves of the first upper and lower rollers in the last group of the plurality of roller groups is lower than that of the other groups.

6. The multi-stage pressing method for honeycomb fireproof and thermal insulation material as described in claim 5, characterized in that, The Shore hardness of the buffer sleeves of the first upper and lower rollers in the last group of the plurality of roller sets is 45-50, and the Shore strength of the buffer sleeves of the first upper and lower rollers in the remaining groups is 50-60.

7. The multi-stage pressing method for honeycomb fireproof and thermal insulation material as described in claim 1 or 6, characterized in that, The Shore strength of the buffer roller sleeves of the second upper and lower rolling rollers is 45-40.

8. The multi-stage pressing method for honeycomb fireproof and thermal insulation material as described in claim 1, characterized in that, Transition rollers are provided between adjacent first rolling rollers and between adjacent second rolling rollers.

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