Preparation method for spreading and smoothing paper surface after hot rolling of high-performance aramid paper

Abstract

A preparation method for spreading and smoothing a paper surface after hot rolling of high-performance aramid paper. The preparation method comprises: selecting aramid paper of different thicknesses, and dividing the aramid paper into thin paper and thick paper; and separately performing hot rolling on the thin aramid paper and the thick aramid paper, observing and recording the surface smoothness of the thin aramid paper and the thick aramid paper, then arranging two guide rollers, the height of which can be adjusted vertically, between a hot rolling machine and a winding frame, adjusting the heights of the guide rollers to change the contact areas between the aramid paper and the guide rollers, observing the surface smoothness of the aramid paper after hot rolling, and comparing the surface smoothness with that of the aramid paper after hot rolling when the guide rollers are not added. The heights of the guide rollers are adjusted multiple times to change the contact area between the guide rollers and the thin aramid paper and the contact area between the guide rollers and the thick aramid paper, the surface smoothness of the aramid paper under different contact areas is observed and recorded, and an optimal contact area between the thin aramid paper and the guide rollers and an optimal contact area between the thick aramid paper and the guide rollers are found.

Description

A preparation method for high-performance aramid paper to make the paper surface stretch and smooth after hot rolling Technical Field

[0001] The invention belongs to the technical field of aramid paper preparation, and specifically relates to a preparation method of high-performance aramid paper by making the paper surface stretch and smooth after hot rolling. Background Art

[0002] Aramid paper's superior electrical properties, tensile strength, and lightweight construction make it widely used in insulation and honeycomb applications. It is a key national strategic material and a key industry receiving national support and development. Currently, my country's high-end aramid paper market is virtually monopolized by foreign countries, with the majority of its production relying on imports. It is widely used in key areas of national economic development, such as insulation for high-temperature transformers, cables, wires, and nuclear power equipment; high-end electronics and circuit boards; lightweight, high-rigidity honeycomb components for secondary load-bearing applications in aerospace, rail transit, yachts, ships, and building materials; and protective workwear fabrics for special fire protection, metallurgy, chemicals, electricity, petroleum, and combat operations.

[0003] In the existing technology, during the preparation process of aramid paper, it needs to undergo high temperature and high pressure in a hot rolling mill to achieve high-density crystal transformation, so as to achieve excellent electrical properties and tensile strength. However, in actual operation, once the aramid paper is subjected to high temperature and high pressure, it will be affected by the paper's basis weight, moisture uniformity, fiber arrangement in the paper, and stress generated by the cross-rolling of the hot rolling rollers. There will be a certain range of deviations in thermal shrinkage, resulting in slight deformation of the paper surface, causing uneven winding or wrinkles. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method for high-performance aramid paper that allows the paper surface to stretch and flatten after hot rolling, so as to solve the problem that after aramid paper is subjected to high temperature and high pressure, there will be a certain range of deviations in thermal shrinkage, which will cause slight deformation of the paper surface, resulting in uneven winding or wrinkles.

[0005] In order to achieve the above object, the present invention provides the following technical solution: a method for preparing high-performance aramid paper to make the paper surface stretch and flat after hot rolling, comprising the following steps:

[0006] Sp1: Select aramid paper of different thicknesses and classify the aramid paper into thin paper and thick paper;

[0007] Sp2: Hot-rolling the aramid tissue paper, observing and recording the surface smoothness of the hot-rolled aramid tissue paper; then, installing two guide rollers with adjustable upper and lower heights between the hot rolling mill and the winding frame, selecting aramid tissue paper of the same thickness for hot rolling, and placing the hot-rolled aramid tissue paper in contact with the guide rollers, observing and recording the surface smoothness of the hot-rolled aramid tissue paper, and finally comparing the surface smoothness of the aramid tissue paper after the two hot rolling processes;

[0008] Sp3: Hot-roll the aramid thick paper, observe and record the surface flatness of the hot-rolled aramid thick paper; then, two guide rollers with adjustable upper and lower heights are installed between the hot rolling mill and the winding frame, and aramid thick paper of the same thickness is selected for hot rolling. The hot-rolled aramid thick paper is brought into contact with the guide rollers, and the surface flatness of the hot-rolled aramid thick paper is observed and recorded. Finally, the surface flatness of the aramid thick paper after the two hot rolling processes is compared.

[0009] Preferably, the thickness of thin paper is 0.04mm-0.08mm, and the basis weight is 24.5g / ㎡-63g / ㎡; the thickness of thick paper is 0.13mm-0.38mm, and the basis weight is 115g / ㎡-360g / ㎡; after hot rolling, aramid paper of different thicknesses is in the middle section of the winder. If a pair of guide rollers are added to thread the paper, the stretching and smoothing of the paper will be greatly affected. Therefore, the present invention selects aramid paper of different thicknesses for testing respectively, and the test results are compared to obtain the effect of the guide rollers on the stretching and smoothing of the paper surface after hot rolling.

[0010] Preferably, a three-roller two-roll hot rolling mill is used to hot-roll the aramid thin paper, with a hot rolling temperature of 200-250° C. and a line pressure of 55-110 N / mm.

[0011] Preferably, the aramid thin paper on the unwinding stand passes through the first lap roller, passes over the second lap roller near the entrance of the hot rolling mill conveying chamber, and then passes between the third hot roller and the second hot roller, and then passes between the second hot roller and the first hot roller, and then passes out of the first hot roller and passes between two fixed rollers, and finally passes through multiple lap rollers and is wound on the surface of the winding roller. The stiffness and flatness of the surface of the aramid thin paper after hot rolling are observed, and the surface flatness of the aramid thin paper after hot rolling without adding guide rollers is used as a reference standard, and compared with the surface flatness of the aramid thin paper after hot rolling with the guide rollers added.

[0012] Preferably, aramid thin paper of the same specification is selected, the aramid thin paper is passed through the first lap roller, passed over the second lap roller near the inlet of the hot rolling mill conveying chamber, and then the aramid thin paper is passed between the third hot roller and the second hot roller, and then between the second hot roller and the first hot roller, and then passed out of the first hot roller and passed between the two fixed rollers. Two upper and lower height-adjustable guide rollers are provided between the hot rolling mill and the winding frame. The height of the guide roller is adjusted to be above the height of the fixed roller. The hot-rolled aramid thin paper is passed from the surface of the upper guide roller, passed through the bottom of the upper guide roller and out from the bottom of the lower guide roller, and finally passed through multiple lap rollers and wound on the surface of the winding roller. The stiffness and flatness of the surface of the aramid thin paper after hot rolling are observed. The slight deformation of the paper surface of thin paper is greater than that of thick paper, so the contact area with the adjustable guide roller is as large as possible. The height of the guide roller is adjusted to be above the height of the fixed roller to increase the contact area between the aramid thin paper and the adjustable guide roller.

[0013] Preferably, a three-roller two-roll hot rolling mill is used to hot-roll the aramid thick paper, with a hot rolling temperature of 250-300° C. and a line pressure of 110-220 N / mm.

[0014] Preferably, the aramid thick paper on the unwinding stand is passed through the first lap roller, passed over the second lap roller near the entrance of the hot rolling mill conveying chamber, and then the aramid thick paper is passed between the third hot roller and the second hot roller, and then between the second hot roller and the first hot roller, and then passed out of the first hot roller and passed between two fixed rollers, and finally passed through multiple lap rollers and wound on the surface of the winding roller. The stiffness and flatness of the surface of the aramid thick paper after hot rolling are observed, and the surface flatness of the aramid thick paper after hot rolling without adding guide rollers is used as a reference standard, and compared with the surface flatness of the aramid thick paper after hot rolling with the guide rollers added.

[0015] Preferably, aramid thick paper of the same specification is selected, and the aramid thick paper is passed through the first lap roller, and passed over the second lap roller near the inlet of the hot rolling mill conveying chamber, and then the aramid thick paper is passed between the third hot roller and the second hot roller, and then between the second hot roller and the first hot roller, and then passed out of the first hot roller and passed between the two fixed rollers. Two upper and lower height-adjustable guide rollers are provided between the hot rolling mill and the winding frame. The height of the guide roller is adjusted to be below the height of the fixed roller. The hot-rolled aramid thick paper is passed from the surface of the upper guide roller, and finally passed through multiple lap rollers and wound on the surface of the winding roller. The stiffness and flatness of the surface of the aramid thick paper after hot rolling are observed. As the thickness of the thick paper increases, the slight deformation of the paper surface also decreases. The height of the guide roller is adjusted to be below the height of the fixed roller to reduce the contact area between the aramid thick paper and the adjustable guide roller.

[0016] Preferably, the guide roller is adjusted to be divided into an upper roller and a lower roller, and the height of the upper roller and the lower roller is adjusted by a lifting device. The height of the guide roller is adjusted multiple times to change the contact area between the guide roller and the hot-rolled aramid paper. The flatness of the aramid paper surface under different contact areas is observed and recorded, and the optimal contact area between the guide roller and the aramid thin paper after hot rolling and the aramid thick paper after hot rolling is found respectively.

[0017] The beneficial effects of the present invention are as follows:

[0018] In the present invention, a pair of guide rollers capable of upward and downward displacement and multi-angle adjustment are added to the middle section of the winder after the aramid paper is hot-rolled to thread the paper, and aramid papers of different thicknesses are hot-rolled respectively. The contact area between the thin aramid paper and the guide rollers is changed by adjusting the guide rollers, and the contact area between the thick aramid paper and the guide rollers is changed. Comparative tests have shown that adding a pair of guide rollers to thread the aramid paper of different thicknesses in the middle section of the winder after the hot rolling has a great influence on the stretching and smoothing of the paper, and the slight deformation of the paper surface of the thin aramid paper is greater than that of the thick aramid paper. The contact area with the adjustable guide rollers is as large as possible, so that the surface of the thin aramid paper after hot rolling is more stretched and smoothed. The slight deformation of the paper surface of the thick paper decreases with increasing thickness, and the contact area with the adjustable guide rollers is as small as possible, so that the surface of the thick aramid paper after hot rolling is more stretched and smoothed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic diagram of hot rolling and unwinding of aramid paper according to the present invention;

[0020] FIG2 is a schematic diagram of the aramid tissue paper of the present invention being wound and unwound through adjustable guide rollers;

[0021] FIG3 is a schematic diagram of the aramid thick paper of the present invention being wound and unwound through adjustable guide rollers. Implementation Method

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0023] As shown in FIG1 to FIG3, an embodiment of the present invention provides a method for preparing high-performance aramid paper to make the paper surface stretch and flat after hot rolling, comprising the following steps:

[0024] Sp1: Select aramid paper of different thicknesses and classify the aramid paper into thin paper and thick paper;

[0025] Sp2: Hot-rolling the aramid tissue paper, observing and recording the surface smoothness of the hot-rolled aramid tissue paper; then, installing two guide rollers with adjustable upper and lower heights between the hot rolling mill and the winding frame, selecting aramid tissue paper of the same thickness for hot rolling, and placing the hot-rolled aramid tissue paper in contact with the guide rollers, observing and recording the surface smoothness of the hot-rolled aramid tissue paper, and finally comparing the surface smoothness of the aramid tissue paper after the two hot rolling processes;

[0026] Sp3: Hot-roll the aramid thick paper, observe and record the surface flatness of the hot-rolled aramid thick paper; then, two guide rollers with adjustable upper and lower heights are installed between the hot rolling mill and the winding frame, and aramid thick paper of the same thickness is selected for hot rolling. The hot-rolled aramid thick paper is brought into contact with the guide rollers, and the surface flatness of the hot-rolled aramid thick paper is observed and recorded. Finally, the surface flatness of the aramid thick paper after the two hot rolling processes is compared.

[0027] Thin paper has a thickness of 0.04mm-0.08mm and a basis weight of 24.5g / ㎡-63g / ㎡, while thick paper has a thickness of 0.13mm-0.38mm and a basis weight of 115g / ㎡-360g / ㎡. Aramid paper of varying thicknesses, after hot rolling, has a significant impact on its smoothness and flatness if a pair of guide rollers are added to the middle section of the winder to thread the paper. To address this issue, the present invention tested aramid paper of varying thicknesses and compared the test results to determine the effect of guide rollers on the smoothness and flatness of the paper surface after hot rolling.

[0028] A three-roller two-roll hot rolling mill is used to hot-roll the aramid thin paper, with a hot rolling temperature of 200-250°C and a line pressure of 55-110N / mm.

[0029] The aramid tissue paper on the unwinding stand was passed over the first lap roller and then over the second lap roller near the entrance of the hot rolling mill. The aramid tissue paper then passed between the third and second hot rollers, then between the second and first hot rollers, then out of the first hot roller and between two fixed rollers. Finally, it passed through multiple lap rollers and was wrapped around the winding roller. The stiffness and flatness of the aramid tissue paper after hot rolling were observed. The surface flatness of the aramid tissue paper after hot rolling without the guide roller was used as a reference standard and compared with the surface flatness of the aramid tissue paper after hot rolling with the guide roller added.

[0030] Select aramid thin paper of the same specification, pass the aramid thin paper through the first lap roller, pass over the second lap roller near the entrance of the hot rolling mill conveying chamber, then pass the aramid thin paper between the third hot roller and the second hot roller, then pass between the second hot roller and the first hot roller, then pass out of the first hot roller and pass between the two fixed rollers. There are two upper and lower height-adjustable guide rollers between the hot rolling mill and the winding frame. Adjust the height of the guide roller to above the height of the fixed roller, and then pass the hot-rolled aramid thin paper from the surface of the upper guide roller. Insert the paper, pass through the bottom of the upper guide roller and exit from the bottom of the lower guide roller, and finally pass through multiple lap rollers to be wound on the surface of the winder roller. Observe the stiffness and flatness of the surface of the aramid thin paper after hot rolling. The slight deformation of the paper surface of thin paper is greater than that of thick paper, so the contact area with the adjustable guide roller should be as large as possible. Adjust the guide roller height to above the fixed roller height to increase the contact area between the aramid thin paper and the adjustable guide roller. Observe the stiffness and flatness of the surfaces of two rolls of aramid thin paper of the same thickness and specification. The surface of the aramid thin paper in contact with the adjustable guide roller is more stretched and flat.

[0031] A three-roller two-roll hot rolling mill is used to hot roll the aramid thick paper, with a hot rolling temperature of 250-300°C and a line pressure of 110-220N / mm.

[0032] The aramid thick paper on the unwinding stand passes through the first lap roller and passes over the second lap roller near the entrance of the hot rolling mill conveying chamber. The aramid thick paper then passes between the third hot roller and the second hot roller, then between the second hot roller and the first hot roller, then out of the first hot roller and between two fixed rollers, and finally passes through multiple lap rollers and is wound on the surface of the winding roller. The stiffness and flatness of the surface of the aramid thick paper after hot rolling are observed. The surface flatness of the aramid thick paper after hot rolling without adding guide rollers is used as a reference standard and compared with the surface flatness of the aramid thick paper after hot rolling with the guide rollers added.

[0033] Select aramid thick paper of the same specification, pass the aramid thick paper through the first lap roller, pass over the second lap roller near the entrance of the hot rolling mill conveying chamber, then pass the aramid thick paper through the third hot roller and the second hot roller, then pass through the second hot roller and the first hot roller, then pass out of the first hot roller and pass through the two fixed rollers. Two upper and lower height-adjustable guide rollers are provided between the hot rolling mill and the winding frame. Adjust the height of the guide roller and adjust the guide roller height to below the height of the fixed roller. Pass the hot-rolled aramid thick paper from the surface of the upper guide roller and finally pass through multiple lap rollers to be wound on the surface of the winding roller. Observe the stiffness and flatness of the surface of the aramid thick paper after hot rolling. As the thickness of the thick paper increases, the slight deformation of the paper surface also decreases. Adjust the guide roller height to below the height of the fixed roller to reduce the contact area between the aramid thick paper and the adjustable guide roller. Observe the stiffness and flatness of the surfaces of two rolls of aramid thick paper of the same thickness and specification. The surface of the aramid thick paper in contact with the adjustable guide roller is more stretched and flat.

[0034] The adjustable guide roller is divided into an upper roller and a lower roller. The height of the upper roller and the lower roller is adjusted by the lifting device. The height of the guide roller is adjusted multiple times to change the contact area between the guide roller and the hot-rolled aramid paper. The flatness of the aramid paper surface under different contact areas is observed and recorded, and the optimal contact area between the guide roller and the aramid thin paper after hot rolling and the aramid thick paper after hot rolling is found respectively.

[0035] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0036] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-performance aramid paper to make the paper surface stretch and flat after hot rolling, characterized in that: The following steps are involved: Sp1: Select aramid paper of different thicknesses and divide the aramid paper into thin paper and thick paper; Sp2: hot rolling the aramid thin paper, observing and recording the surface flatness of the hot-rolled aramid thin paper; then, two guide rollers with adjustable upper and lower heights are arranged between the hot rolling mill and the winding frame, aramid thin paper of the same thickness is selected for hot rolling, and the hot-rolled aramid thin paper is brought into contact with the guide rollers, and the surface flatness of the hot-rolled aramid thin paper is observed and recorded, and finally the surface flatness of the aramid thin paper after the two hot rollings is compared; Sp3: Hot-roll the aramid thick paper, observe and record the surface flatness of the hot-rolled aramid thick paper; then, two upper and lower height-adjustable guide rollers are set between the hot rolling mill and the winding frame, and aramid thick paper of the same thickness is selected for hot rolling. The hot-rolled aramid thick paper is brought into contact with the guide rollers, and the surface flatness of the hot-rolled aramid thick paper is observed and recorded. Finally, the surface flatness of the aramid thick paper after the two hot rollings is compared.

2. The method for preparing aramid paper to make the paper surface stretch and flat after hot rolling according to claim 1, characterized in that: The thickness of thin paper is 0.04mm-0.08mm, and the basis weight is 24.5g / ㎡-63g / ㎡. The thickness of thick paper is 0.13mm-0.38mm, and the basis weight is 115g / ㎡-360g / ㎡.

3. The method for preparing high-performance aramid paper by making the paper surface stretch and flat after hot rolling according to claim 1, characterized in that: A three-roller two-roll hot rolling mill is used to hot roll the aramid thin paper, the hot rolling temperature is 200-250°C, and the line pressure is 55-110N / mm.

4. The method for preparing aramid paper to make the paper surface stretch and flat after hot rolling according to claim 3, characterized in that: The aramid thin paper on the unwinding stand passes through the first lap roller, passes over the second lap roller near the entrance of the hot rolling mill conveying chamber, and then passes between the third hot roller and the second hot roller, and then passes between the second hot roller and the first hot roller, then passes out of the first hot roller and passes between two fixed rollers, and finally passes through multiple lap rollers and is wound on the surface of the winding roller. The stiffness and flatness of the surface of the aramid thin paper after hot rolling are observed.

5. The method for preparing aramid paper to make the paper surface stretch and flat after hot rolling according to claim 4, characterized in that: Select aramid thin paper of the same specification, pass the aramid thin paper through the first lap roller, pass over the second lap roller near the entrance of the hot rolling mill conveying chamber, then pass the aramid thin paper between the third hot roller and the second hot roller, then pass between the second hot roller and the first hot roller, then pass out of the first hot roller and pass between the two fixed rollers. Two upper and lower height-adjustable guide rollers are arranged between the hot rolling mill and the winding frame. The height of the guide roller is adjusted to be above the height of the fixed roller. The hot-rolled aramid thin paper is passed from the surface of the upper guide roller, passed through the bottom of the upper guide roller and passed out from the bottom of the lower guide roller, and finally passed through multiple lap rollers and wound on the surface of the winding roller. The stiffness and flatness of the surface of the hot-rolled aramid thin paper are observed.

6. The method for preparing high-performance aramid paper to make the paper surface stretch and flat after hot rolling according to claim 1, characterized in that: A three-roller two-roll hot rolling mill is used to hot roll the aramid thick paper, the hot rolling temperature is 250-300℃, and the line pressure is 110-220N / mm.

7. The method for preparing aramid paper to make the paper surface stretch and flat after hot rolling according to claim 6, characterized in that: The aramid thick paper on the unwinding stand passes through the first lap roller, passes over the second lap roller near the entrance of the hot rolling mill conveying chamber, and then passes between the third hot roller and the second hot roller, and then passes between the second hot roller and the first hot roller, then passes out of the first hot roller and passes between the two fixed rollers, and finally passes through multiple lap rollers and is wound on the surface of the winding roller. Observe the stiffness and flatness of the surface of the aramid thick paper after hot rolling.

8. The method for preparing aramid paper to make the paper surface stretch and flat after hot rolling according to claim 7, characterized in that: Select aramid thick paper of the same specification, pass the aramid thick paper through the first lap roller, pass over the second lap roller near the entrance of the hot rolling mill conveying chamber, then pass the aramid thick paper between the third hot roller and the second hot roller, then pass between the second hot roller and the first hot roller, then pass out of the first hot roller and pass between the two fixed rollers. Two upper and lower height-adjustable guide rollers are provided between the hot rolling mill and the winding frame. Adjust the height of the guide roller to below the height of the fixed roller, pass the hot-rolled aramid thick paper from the surface of the upper guide roller, and finally pass through multiple lap rollers and wrap around the surface of the winding roller, and observe the stiffness and flatness of the surface of the hot-rolled aramid thick paper.

9. The method for preparing aramid paper to make the paper surface stretch and smooth after hot rolling according to claim 1, characterized in that: The adjustable guide roller is divided into an upper roller and a lower roller. The height of the upper roller and the lower roller is adjusted by a lifting device. The height of the guide roller is adjusted multiple times to change the contact area between the guide roller and the hot-rolled aramid paper. The flatness of the aramid paper surface under different contact areas is observed and recorded, and the optimal contact area between the guide roller and the aramid thin paper after hot rolling and the aramid thick paper after hot rolling is found out.

Images