High temperature resistant liquid silicone rubber composite longitudinal rubber roller

Abstract

This invention discloses a high-temperature resistant liquid silicone composite longitudinal stretching roller, relating to the technical field of film stretching equipment. It includes a longitudinal stretching roller body, the interior and exterior of which are respectively composed of a metal roller core and a heat-resistant silicone layer. Between the metal roller core and the heat-resistant silicone layer, a heat-regulating layer and a pressure self-compensating layer are sequentially arranged from the inside to the outside. The heat-regulating layer consists of metal rings evenly spaced around the outside of the metal roller core. The pressure self-compensating layer consists of continuously arranged annular hydraulic bladders and elastic energy storage bladders evenly distributed in the middle of the annular hydraulic bladders. This high-temperature resistant liquid silicone composite longitudinal stretching roller, with its internal cooling medium channel in the roller core, phase change heat transfer and axial superconducting heat conduction of the heat-regulating layer, hydraulic-elastic synergistic compensation of the pressure self-compensating layer, and high-temperature wear-resistant and anti-stick design of the surface heat-resistant silicone layer, collectively solves the problems of insufficient high-temperature resistance, large temperature difference on the roller surface, and uneven axial pressure in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of film stretching equipment technology, specifically to a high-temperature resistant liquid silicone composite longitudinal stretching roller. Background Technology

[0002] The longitudinal stretching machine (MDO) is a core piece of equipment in the production process of thin films, lithium battery separators, and polymer functional films. The stretching section is a crucial station for the entire production line, determining the mechanical properties of the film. It primarily uses multiple sets of rollers to perform high-temperature longitudinal stretching and shaping of the film material, directly determining the thickness uniformity, surface smoothness, tensile strength, and yield of the finished film. Under actual high-temperature longitudinal stretching conditions, the rollers at the MDO stretching station must operate in a high-temperature environment for extended periods, simultaneously undertaking the functions of continuous and uniform stretching of the film material, bonding support, and shaping constraint. These conditions place stringent requirements on the rollers: they must achieve stable operation under high-temperature conditions while ensuring a uniform temperature field on the roller surface and consistent axial direction of the roller body. Applying pressure evenly achieves uniform stretching of the film material, surface anti-sticking, and anti-scratch during transport, thereby stabilizing and controlling the consistency of film thickness, improving the tensile strength and flatness of the film material, and effectively reducing production defects such as film breakage, wrinkles, thickness deviation, and surface defects during high-temperature and high-speed operation. Currently, longitudinal stretching rollers mostly adopt a structure of liquid silicone coating a metal roller core. Liquid silicone rollers are mainly used in film processing processes such as casting, calendering, coating, and lamination. Traditional liquid silicone rollers mainly consist of a roller body and a silicone sleeve covering the roller body. However, during use, the roller body is heated by circulating heat transfer oil, which has problems such as lag in temperature control and poor uniformity.

[0003] To address the aforementioned deficiencies, existing technology (Chinese patent publication number CN117103655A, published on 2023-11-24) describes a longitudinal tension roller with a wear-resistant and anti-stick coating for a film production line. This roller uses a fan-shaped disc to separate the suction components (first guide tube, second guide tube, and arc-shaped tube) from the heating component (oil storage tube). Before contacting the film, the longitudinal tension roller is heated by the oil storage tube, thus providing the film with the heat required for stretching upon contact and preventing heat loss. By controlling the intermittent compression of the elastic frame by the pressure plate, the heat between the longitudinal tension roller and the oil storage tube, and between the elastic frame and the longitudinal tension roller, is transferred back and forth through the longitudinal tension roller's through-hole. This effectively heats the through-hole and ensures that ambient temperature gas enters only from the groove of the lower first mounting plate, while hot gas exits only from the groove of the upper first mounting plate to preheat the film. This ensures that the film at the through-hole receives the same amount of heat as the rest of the film, guaranteeing uniform stretching.

[0004] The prior art (Chinese patent announcement number CN113752444B, announcement date 2025-02-25) describes a zero-temperature difference spiral flow channel heat exchange roller for a longitudinal drawing machine. It features a connecting seat fixed to the outer surface of a return pipe, and a liquid inlet connector movably connected to the outer surface of the connecting seat. A sealing ring is fitted at the junction of the liquid inlet connector and the connecting seat. The sealing ring abuts against an umbrella-shaped sealing clamp fixed to the connecting seat, ensuring a tight seal between the liquid inlet connector and the connecting seat. The abutment of the umbrella-shaped sealing clamp ensures that the sealing ring remains firmly against the liquid inlet connector and the connecting seat, preventing... Wear of the sealing ring affects the sealing performance between the inlet connector and the connecting seat. To improve dynamic sealing, spiral blades are evenly fixed on the return pipe, with the thickness of the spiral blades increasing from the drain pipe towards the through hole. This makes the water flow towards the through hole more aggressive, increasing the flow rate and carrying away more heat. The heat loss during water flow causes the roller surface temperature to approach zero. Combined with the heat insulation of the heat-conducting cylinder, the uniformity of heat exchange is further improved. At the same time, the thickest part of the heat-conducting cylinder is exactly opposite to the thickest part of the spiral blade, which perfectly compensates for the weight difference between the upper and lower ends of the exchange roller, ensuring the dynamic balance of the exchange roller.

[0005] The above solutions rely on the complex mechanical circulation of gas pumped by the elastic frame during use, resulting in low heat transfer efficiency and poor reliability. Alternatively, a variable cross-section spiral flow channel can be used to compensate for temperature differences, but this is only applicable to metal heating rollers and the heat uniformity is limited by fixed design conditions. Furthermore, it cannot compensate for any form of uneven local pressure caused by roller roundness error, thermal expansion deformation, and film transverse thickness fluctuations. The contact pressure distribution problem between the longitudinal stretching roller and the steel roller directly affects the film stretching uniformity and product quality. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature resistant liquid silicone composite longitudinal stretching roller to solve the problems mentioned in the background art. These problems include the lack of an efficient, passive, and suitable heat equalization method for silicone-coated rollers, and the inability to compensate for local pressure unevenness caused by roller roundness error, thermal expansion deformation, and film transverse thickness fluctuation. The contact pressure distribution problem between the longitudinal stretching roller and the steel roller directly affects the film stretching uniformity and product quality.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature resistant liquid silicone composite longitudinal tension roller, comprising a longitudinal tension roller body, wherein the interior and exterior of the longitudinal tension roller body are respectively composed of a metal roller core and a heat-resistant silicone layer, and a heat equalization layer and a pressure self-compensation layer are sequentially arranged from the inside to the outside between the metal roller core and the heat-resistant silicone layer.

[0008] The metal roller core is a hollow shaft with a cooling medium flow channel extending spirally along the axial direction inside. The heat equalization layer is a metal collar sleeved at equal intervals outside the metal roller core. It has a closed annular heat equalization cavity inside, which is filled with a phase change heat transfer working fluid and has a capillary liquid wick structure. A heat insulation ring is provided at the gap of the metal collar. The pressure self-compensation layer consists of annular hydraulic bladders arranged continuously along the axial direction and elastic energy storage bladders distributed at equal intervals in the middle of the annular hydraulic bladders. Adjacent annular hydraulic bladders are connected by a throttling tube.

[0009] Furthermore, the left and right sides of the cooling medium flow channel are respectively provided with a cooling medium inlet and an outlet, and the cooling medium inlet and outlet flanges and bearing mounting journals are welded to the outside of the cooling medium flow channel inlet and outlet.

[0010] Furthermore, a heat-conducting sheet is fixed on the inner wall of the heat-uniformation cavity of the metal collar, and a capillary liquid-absorbing core structure is integrally provided on the heat-conducting sheet to form an annular heat-uniformation plate. The capillary liquid-absorbing core structure is formed by sintering metal powder, and the heat-uniformation cavity is filled with water.

[0011] Furthermore, the metal collar is divided into multiple independent heat-equalizing units by the heat-insulating ring, and the heat-insulating ring is made of polytetrafluoroethylene or polyimide.

[0012] Furthermore, an axial heat superconducting system is provided on the outside of the heat homogenizing layer. The axial heat superconducting system includes axial heat superconducting tubes that are embedded at equal angles in the grooves of the outer wall of the heat homogenizing layer. The axial heat superconducting tubes penetrate multiple heat homogenizing units along the axial direction and are connected at the heat insulation ring between adjacent heat homogenizing units by expanded graphite flexible seals.

[0013] Furthermore, the axial thermal superconductor is provided with a gradient capillary structure inside, and the capillary pore size of the gradient capillary structure gradually decreases from the middle of the axial thermal superconductor to both ends, and the gradient capillary structure has the same composition as the capillary liquid absorption core structure.

[0014] Furthermore, the annular hydraulic bladder is formed by an inner rigid wall and an outer elastic diaphragm. The annular hydraulic bladder is filled with silicone oil. The inner rigid wall is fixed to the outer surface of the heat-uniforming layer. The outer elastic diaphragm is a fluorosilicone rubber sheet.

[0015] Furthermore, the elastomeric energy storage bladder contains a sleeve and a rod, which are connected and fitted together, and an energy storage spring is provided within the space where the sleeve and rod are fitted together.

[0016] Furthermore, the outer surface of the heat homogenizing layer and the inner wall of the pressure self-compensating layer are both plasma-treated and coated with a silane coupling agent primer layer.

[0017] Furthermore, the heat-resistant silicone layer is coated on the outer surface of the pressure self-compensating layer. The heat-resistant silicone layer is composed of addition-type liquid silicone rubber doped with composite heat-resistant filler and release agent. The composite heat-resistant filler is a mixture of iron oxide, cerium oxide and hexagonal boron nitride. The release agent is trifluoropropylmethylcyclotrisiloxane homopolymer. The heat-resistant silicone layer contains irreversible thermochromic particles.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This high-temperature resistant liquid silicone composite longitudinal stretching roller, during use, utilizes a four-layer structure working synergistically: a metal roller core for temperature control, a heat equalization layer with phase change and superconducting heat equalization, a pressure self-compensation layer with hydraulic and elastic synergistic compensation, and a heat-resistant silicone layer for high-temperature anti-sticking and wear resistance. This structure addresses the shortcomings of existing technologies, such as low heat transfer efficiency, large temperature difference, and uneven pressure. It is adapted to the requirements of the high-temperature longitudinal stretching core station, achieving a comprehensive effect of uniform film stretching, anti-sticking and anti-scratch, uniform film thickness, improved strength and flatness, and reduced film breakage rate. This significantly improves the production yield and stability of high-end functional film materials.

[0020] 1. Furthermore, by equally spaced metal rings with built-in phase change heat homogenizing chambers and capillary liquid absorption core structures on the outside of the metal roller core, and in conjunction with heat insulation rings at the gaps, passive phase change self-homogenization of circumferential temperature is achieved. At the same time, the axial heat superconducting pipe embedded in the outer wall of the heat homogenizing layer and its internal gradient capillary structure force the working fluid to flow back axially, effectively compensating for the axial heat conduction blockage caused by the heat insulation ring, making the axial and circumferential temperature distribution of the entire roller highly uniform, and eliminating the temperature lag and gradient problems of traditional heating rollers.

[0021] 2. Furthermore, the annular hydraulic bladder, formed by an inner rigid wall and an outer elastic diaphragm, is filled with silicone oil. Adjacent bladders are connected by a throttling tube. When the local pressure increases, the silicone oil slowly flows to the low-pressure area, achieving pressure redistribution. Combined with the elastomeric energy storage bladders and their built-in energy storage springs evenly distributed in the middle of the bladder, pressure pulsation can be quickly suppressed. This hydraulic elastic coupling structure can passively compensate for pressure unevenness caused by roundness error, thermal deformation, and film thickness fluctuation without external control, avoiding film scratches, slippage, or uneven stretching.

[0022] 3. Furthermore, the heat-resistant silicone layer is composed of addition-type liquid silicone rubber doped with iron oxide, cerium oxide and hexagonal boron nitride composite heat-resistant filler and trifluoropropylmethylcyclotrisiloxane homopolymer release agent. The composite filler inhibits the high-temperature oxidative degradation of silicone rubber, hexagonal boron nitride improves heat diffusion and reduces friction, and the release agent forms a low surface energy anti-stick layer to prevent film adhesion. Irreversible thermochromic particles provide a visual thermal history indication, thus comprehensively extending the high-temperature service life of the rubber roller.

[0023] 4. Furthermore, after plasma activation treatment, the outer surface of the heat-uniform layer and the inner wall of the pressure self-compensation layer are coated with a silane coupling agent primer layer, which forms a transition interface with chemical covalent bonds between the metal collar, heat insulation ring, hydraulic bladder and heat-resistant silicone layer. Compared with physical coating, this bonding method has higher shear strength and heat aging stability, ensuring that the functional layers do not delaminate or slip under high temperature operation and mechanical extrusion, and ensuring the long-term reliable operation of the entire roll. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the longitudinal tension rubber roller of the present invention;

[0025] Figure 2 This is a schematic diagram of the side cross-section structure of the present invention;

[0026] Figure 3 This is an exploded structural diagram of the longitudinal tension rubber roller of the present invention;

[0027] Figure 4 This is a schematic diagram of the cross-sectional structure of the heat homogenization layer of the present invention;

[0028] Figure 5 This is a schematic diagram of the partial explosion structure of the metal collar and heat insulation ring of the present invention;

[0029] Figure 6 This is a schematic diagram of the internal cross-sectional structure of the heat equalization cavity of the present invention;

[0030] Figure 7 This is a schematic diagram of the axial thermal superconductor structure of the present invention.

[0031] Figure 8 This is a front view schematic diagram of the pressure self-compensation layer structure of the present invention;

[0032] Figure 9 This is a top view of the overall cross-sectional structure of the pressure self-compensating layer of the present invention;

[0033] Figure 10 This is a schematic cross-sectional view of the internal structure of the elastomer energy storage bag of the present invention.

[0034] In the diagram: 1. Longitudinal tension roller body; 101. Metal roller core; 2. Heat equalization layer; 201. Metal collar; 202. Heat insulation ring; 203. Heat equalization cavity; 204. Heat-conducting plate; 205. Capillary liquid absorption core structure; 206. Axial heat superconducting pipe; 207. Gradient capillary structure; 3. Pressure self-compensation layer; 301. Annular hydraulic bladder; 3011. Inner ring rigid wall; 3012. Elastic diaphragm; 302. Throttling tube; 303. Elastomer energy storage bladder; 304. Sleeve; 305. Sleeve rod; 306. Energy storage spring; 4. Heat-resistant silicone layer; 5. Cooling medium flow channel. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] This invention provides a high-temperature resistant liquid silicone composite longitudinal tension roller, comprising a longitudinal tension roller body 1. The interior and exterior of the longitudinal tension roller body 1 are respectively composed of a metal roller core 101 and a heat-resistant silicone layer 4. A heat-regulating layer 2 and a pressure self-compensating layer 3 are sequentially arranged from the inside to the outside between the metal roller core 101 and the heat-resistant silicone layer 4. The metal roller core 101 is a hollow shaft with internally arranged cooling medium channels 5 extending spirally along the axial direction. The heat-regulating layer 2 is an evenly spaced layer sleeved on the outside of the metal roller core 101. The metal collar 201 has a closed annular heat-equalizing cavity 203 inside. The heat-equalizing cavity 203 is filled with a phase change heat transfer working fluid and has a capillary liquid absorption core structure 205. A heat insulation ring 202 is provided at the gap of the metal collar 201. The pressure self-compensation layer 3 is composed of annular hydraulic bladders 301 arranged continuously along the axial direction and elastic energy storage bladders 303 distributed at equal intervals in the middle of the annular hydraulic bladders 301. Adjacent annular hydraulic bladders 301 are connected by a throttling pipe 302.

[0037] refer to Figure 3 - Figure 10 As shown, the overall working principle of the scheme is as follows: basic temperature regulation is achieved through the spiral cooling medium flow channel 5 inside the metal roller core 101; high-precision passive heat equalization in the circumferential and axial directions is achieved through the phase change heat equalization cavity 203 of the metal collar 201 in the heat equalization layer 2 and the axial heat superconductor 206; adaptive balance of contact pressure is achieved through the annular hydraulic bladder 301 and the elastomer energy storage bladder 303 in the pressure self-compensation layer 3; and a stable coating and anti-stick surface at high temperatures is provided through the heat-resistant silicone layer 4. The layers are firmly bonded to each other through plasma treatment and silane coupling agent base layer, which synergistically solves the pain points of insufficient high temperature resistance, large roller surface temperature difference, and uneven axial pressure in the existing technology, adapts to high temperature longitudinal stretching conditions, and achieves uniform film stretching, anti-sticking and anti-scratch, uniform film thickness, improved strength and flatness, and reduced film breakage.

[0038] Specifically, the left and right sides of the cooling medium flow channel 5 are respectively provided with a cooling medium inlet and an outlet, and the external of the cooling medium inlet and outlet of the cooling medium flow channel 5 is welded with cooling medium inlet and outlet flanges and bearing mounting journals.

[0039] refer to Figure 1 - Figure 2As shown, in this scheme, high-temperature longitudinal stretching is not achieved by relying on external heat supply, but by actively regulating the temperature through the spiral cooling medium channel 5 inside the metal roller core 101. Under high-temperature longitudinal stretching conditions, the rubber roller itself passively receives heat conducted from the high-temperature film. In this process, the rubber roller plays the roles of support, stretching, and heat conduction / temperature control. The function of the cooling medium channel 5 is to remove excess heat to prevent overheating, rather than supplying heat. During operation, the external cooling medium, such as water or heat transfer oil, flows in from the inlet, flows axially along the spiral channel 5, and then exits from the outlet. The spiral channel structure increases the contact path and heat exchange area between the medium and the inner wall of the roller core, which can remove the heat conducted to the longitudinal stretching rubber roller body 1 by film stretching, preventing the metal roller core 101 from overheating. This cooling method is active heat exchange, constituting the first stage of temperature regulation of the longitudinal stretching rubber roller body 1.

[0040] Example 1 discloses a heat uniform distribution mechanism, referencing Figure 3 - Figure 7 As shown, the specific structure is as follows: a heat-conducting plate 204 is fixed on the inner wall of the heat-uniformation cavity 203 of the metal collar 201, and a capillary liquid-absorbing core structure 205 is integrally provided on the heat-conducting plate 204 to form an annular heat-uniformation plate. The capillary liquid-absorbing core structure 205 is formed by sintering metal powder, and the heat-uniformation cavity 203 is filled with water. The metal collar 201 is divided into multiple independent heat-uniformation units by the heat insulation ring 202, and the heat insulation ring 202 is made of polytetrafluoroethylene or polyimide.

[0041] refer to Figure 3 - Figure 7As shown, each metal collar 201 has a closed annular heat-uniforming cavity 203 formed inside by electrical discharge machining or precision casting. A heat-conducting plate 204 is fixed to the inner wall of the heat-uniforming cavity 203 by brazing or integral sintering. A capillary wick structure 205 is formed on the heat-conducting plate 204 through a metal powder sintering process, constituting an annular heat-uniforming plate. After vacuuming, the heat-uniforming cavity 203 is filled with a phase-change heat transfer medium, such as water. When the temperature of the rubber roller locally rises, such as in the area in contact with the high-temperature film, the medium in the heat-uniforming cavity 203 absorbs heat and vaporizes. The vapor rapidly diffuses into the low-temperature region within the cavity, condenses, and releases heat. The condensed liquid flows back to the heating zone through the capillary force of the capillary wick structure 205, forming a passive phase-change cycle of evaporation, condensation, and reflux. This process requires no external energy and can achieve rapid uniformization of circumferential and local temperatures within milliseconds. (The text also mentions a heat insulation ring, but this seems unrelated to the heat-uniforming cavity 201.) 202 is made of polytetrafluoroethylene or polyimide material by molding or machining. During assembly, it is pressed into the gap between adjacent metal rings 201. Its low thermal conductivity can block the direct conduction of heat between adjacent heat equalization units and prevent the temperature gradient distribution caused by the axial heat conduction of the metal roller core 101. As a continuous metal component, the metal roller core 101 has a high axial thermal conductivity. When there is a temperature difference in the axial direction of the rubber roller, for example, due to the uneven transverse temperature of the film or the different contact states between the roller surface and the film, heat will be conducted along the axial direction of the metal roller core 101. However, due to the uneven distribution of heat source, the axial heat conduction of the metal roller core 101 alone cannot achieve temperature uniformity. Instead, it may form a temperature gradient distribution along the axial direction, that is, the temperature changes gradient along the axial direction, so that each metal ring 201 can independently achieve its circumferential heat equalization function.

[0042] Furthermore, an axial superconducting heat pipe system is provided on the outside of the heat homogenizing layer 2. The axial superconducting heat pipe system includes an axial superconducting heat pipe 206 that is embedded at equal angles in the groove of the outer wall of the heat homogenizing layer 2. The axial superconducting heat pipe 206 passes through multiple heat homogenizing units along the axial direction and is connected by an expanded graphite flexible seal at the heat insulation ring 202 between adjacent heat homogenizing units. The interior of the axial superconducting heat pipe 206 is provided with a gradient capillary structure 207, and the capillary pore size of the gradient capillary structure 207 gradually decreases from the middle of the axial superconducting heat pipe 206 to both ends. The gradient capillary structure 207 has the same structure as the capillary liquid absorption core structure 205.

[0043] refer to Figure 3 - Figure 7As shown, an axially extending groove is machined on the outer wall of the heat homogenizing layer 2 by CNC milling. An axial heat superconducting pipe 206 is embedded in the groove at equal angles. The axial heat superconducting pipe 206 penetrates multiple heat homogenizing units, and is sealed at the position where it passes through the heat insulation ring 202 using an expanded graphite flexible seal. The interior of the axial heat superconducting pipe 206 is prepared with a gradient capillary structure 207 by gradient powder sintering process. The capillary pore size gradually decreases from the middle of the pipe to both ends. When a temperature difference occurs axially on the rubber roller, the working fluid inside the axial heat superconducting pipe 206 is at a high temperature. Vaporization occurs at the high-temperature end, and the vapor diffuses and condenses along the tube towards the low-temperature end. The liquid refluxes through the gradient capillary structure 207. According to the basic principles of capillary mechanics, the smaller the capillary pore size, the greater the capillary force. As the capillary pore size gradually decreases from the middle to both ends, the resulting capillary force gradually increases, effectively overcoming gravity and vapor flow resistance, achieving directional and rapid reflux of the working fluid. Based on this, combined with the circumferential phase change heat equalization chamber 203 to achieve circumferential temperature uniformity, the entire roller achieves a highly uniform temperature distribution in both the circumferential and axial dimensions, thus strengthening… To compensate for the axial temperature difference, this structure compensates for the axial thermal blockage caused by the heat insulation ring 202, resulting in a highly uniform axial temperature distribution across the entire roller. This application does not rely on the solid-state heat conduction of the metal roller core to achieve axial temperature uniformity, but rather on the synergistic effect of two mechanisms: the heat insulation ring 202 blocks direct solid-state heat conduction between adjacent metal rings 201, preventing a stepped temperature distribution caused by uneven axial heat conduction of the metal roller core 101 itself, allowing each metal ring 201 to independently achieve its circumferential heat uniformity function; the axial heat superconductor 206... Its function is to actively compensate for axial temperature difference. The internal working fluid vaporizes at the high temperature end and diffuses and condenses at the low temperature end. The liquid flows back through the gradient capillary structure 207, thereby realizing the forced transfer and redistribution of axial heat. The heat insulation ring 202 blocks the passive and uneven solid heat conduction path, while the axial heat superconductor 206 establishes an active and controllable phase change heat transfer path. The heat insulation ring 202 eliminates the temperature interference caused by the uneven solid heat conduction of the metal roller core 101, while the axial heat superconductor 206 achieves axial temperature uniformity efficiently through phase change heat transfer.

[0044] Example 2:

[0045] Based on Embodiment 1, a pressure self-compensation mechanism is also disclosed; please refer to [reference needed]. Figure 2 - Figure 3 and Figure 8 - Figure 10Its specific structure is as follows: The annular hydraulic bladder 301 is formed by an inner ring rigid wall 3011 and an outer elastic diaphragm 3012. The annular hydraulic bladder 301 is filled with silicone oil. The inner ring rigid wall 3011 is fixed to the outer surface of the heat equalization layer 2. The outer elastic diaphragm 3012 is a fluorosilicone rubber sheet. The elastic energy storage bladder 303 has a sleeve 304 and a sleeve rod 305 inside, and the sleeve 304 and the sleeve rod 305 are sleeved and connected. An energy storage spring 306 is provided in the space where the sleeve 304 and the sleeve rod 305 are sleeved.

[0046] refer to Figure 2 - Figure 3 and Figure 8 - Figure 10 As shown, each annular hydraulic bladder 301 is formed by an inner rigid wall 3011 and an outer elastic diaphragm 3012. The inner rigid wall 3011 is made of metal sheet rolled and welded or precision cast and then fixed to the outer surface of the heat equalization layer 2. The outer elastic diaphragm 3012 is made of fluorosilicone rubber by compression molding, which has good high temperature resistance and elasticity. The bladder is filled with silicone oil. When the rubber roller and the steel roller are pressed together, if the contact pressure increases at a certain point due to the roundness error of the rubber roller, thermal expansion deformation, or lateral thickness fluctuation of the diaphragm, the annular hydraulic bladder 301 at that point will be squeezed and deformed. The internal silicone oil will slowly flow to the adjacent low-pressure bladder through the throttling pipe 302 to achieve pressure redistribution and equalization. The throttling effect of the throttling pipe 302 can suppress To mitigate sudden pressure changes and provide a damping effect, the elastomer energy storage bladder 303 contains a sleeve 304 and a sleeve rod 305, which are precision machined and connected together. An energy storage spring 306 is installed within the sleeve space. After being fully encapsulated, the entire structure is assembled at equal intervals between the annular hydraulic bladders 301. When the system pressure fluctuates, the energy storage spring 306 inside the energy storage bladder 303 is compressed or released, storing or releasing elastic potential energy, which plays a role in smoothing pressure pulsations and maintaining steady-state pressure. This structure enables the pressure self-compensation layer 3 to have both slow pressure equalization capability through silicone oil flow and rapid pressure buffering capability. The energy storage spring 306 ensures that the contact pressure between the roller surface and the film is highly uniform along the axial and circumferential directions.

[0047] Furthermore, the outer surface of the heat homogenizing layer 2 and the inner wall of the pressure self-compensation layer 3 are both plasma treated and coated with a silane coupling agent primer layer.

[0048] Before assembly, the outer surface of the heat-uniforming layer 2 and the inner wall of the pressure self-compensating layer 3 are both subjected to plasma surface treatment using an atmospheric plasma spray gun to remove oil stains, increase surface energy, and introduce polar groups. Subsequently, a silane coupling agent primer layer is applied by spraying or dipping. The plasma treatment changes the surface from hydrophobic to hydrophilic. One end of the silane coupling agent forms a chemical bond with the activated metal or silicone rubber surface, and the other end undergoes a cross-linking reaction with the material of the adjacent layer, thereby significantly improving the interlayer bonding strength and thermal matching, and preventing delamination or relative sliding during high-temperature operation.

[0049] Example 3:

[0050] Based on Example 2, a heat-resistant silicone layer is also disclosed; please refer to [reference needed]. Figure 1 - Figure 2 Its specific structure is as follows: The heat-resistant silicone layer 4 is wrapped around the outer surface of the pressure self-compensating layer 3. The heat-resistant silicone layer 4 is composed of addition-type liquid silicone rubber doped with composite heat-resistant filler and release agent. The composite heat-resistant filler is a mixture of iron oxide, cerium oxide and hexagonal boron nitride. The release agent is trifluoropropylmethylcyclotrisiloxane homopolymer. The heat-resistant silicone layer 4 contains irreversible thermochromic particles.

[0051] refer to Figure 1 - Figure 2 As shown, the heat-resistant silicone layer 4 is coated onto the outer surface of the pressure self-compensating layer 3 using a liquid silicone injection molding process. The material is an addition-type liquid silicone rubber containing composite heat-resistant fillers, a mixture of iron oxide, cerium oxide, and hexagonal boron nitride, release agents, trifluoropropylmethylcyclotrisiloxane homopolymer, and irreversible thermochromic particles. After mixing, the mixture is degassed under vacuum, injected into a mold using a screw injection machine, and then heated for vulcanization. The composite heat-resistant fillers inhibit the side-chain oxidative degradation and main-chain rearrangement of the silicone rubber at high temperatures, improving thermal stability. The release agents reduce surface energy, giving the roller surface anti-stick properties and preventing film adhesion at high temperatures. The thermochromic particles undergo irreversible color changes after exceeding a set temperature, providing a visual indication of whether the roller surface has experienced a heat history and assisting in equipment maintenance.

[0052] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0053] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-temperature resistant liquid silicone composite longitudinal tension roller, comprising a longitudinal tension roller body (1), wherein the interior and exterior of the longitudinal tension roller body (1) are respectively composed of a metal roller core (101) and a heat-resistant silicone layer (4), and a heat-uniform layer (2) and a pressure self-compensation layer (3) are sequentially arranged from the inside to the outside between the metal roller core (101) and the heat-resistant silicone layer (4). Its features are: The metal roller core (101) is a hollow shaft with a cooling medium flow channel (5) extending spirally along the axial direction inside. The heat equalization layer (2) is a metal collar (201) that is equally spaced around the outside of the metal roller core (101). It has a closed annular heat equalization cavity (203) inside. The heat equalization cavity (203) is filled with a phase change heat transfer medium and has a capillary liquid absorption core structure (205). A heat insulation ring (202) is provided at the gap of the metal collar (201). The pressure self-compensation layer (3) is composed of annular hydraulic bladders (301) arranged continuously along the axial direction and elastic energy storage bladders (303) that are equally spaced in the middle of the annular hydraulic bladders (301). Adjacent annular hydraulic bladders (301) are connected by a throttling tube (302).

2. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 1, characterized in that: The cooling medium flow channel (5) is provided with a cooling medium inlet and an outlet on the left and right sides respectively, and the cooling medium inlet and outlet flanges and bearing mounting journals are welded to the outside of the cooling medium flow channel (5).

3. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 1, characterized in that: A heat-conducting plate (204) is fixed on the inner wall of the heat-uniforming cavity (203) of the metal collar (201), and a capillary liquid-absorbing core structure (205) is integrally provided on the heat-conducting plate (204) to form an annular heat-uniforming plate. The capillary liquid-absorbing core structure (205) is formed by sintering metal powder, and the heat-uniforming cavity (203) is filled with water.

4. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 3, characterized in that: The metal collar (201) is divided into multiple independent heat-equalizing units by the heat insulation ring (202), and the heat insulation ring (202) is made of polytetrafluoroethylene or polyimide.

5. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 4, characterized in that: An axial heat superconducting system is also provided outside the heat homogenizing layer (2). The axial heat superconducting system includes an axial heat superconducting tube (206) that is embedded at an equal angle in the groove of the outer wall of the heat homogenizing layer (2). The axial heat superconducting tube (206) passes through multiple heat homogenizing units along the axial direction and is connected by an expanded graphite flexible seal at the heat insulation ring (202) between adjacent heat homogenizing units.

6. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 5, characterized in that: The axial thermal superconductor (206) is provided with a gradient capillary structure (207) inside, and the capillary pore size of the gradient capillary structure (207) gradually decreases from the middle to both ends of the axial thermal superconductor (206), and the gradient capillary structure (207) has the same structure as the capillary liquid absorption core structure (205).

7. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 1, characterized in that: The annular hydraulic bladder (301) is formed by an inner rigid wall (3011) and an outer elastic diaphragm (3012). The annular hydraulic bladder (301) is filled with silicone oil. The inner rigid wall (3011) is fixed to the outer surface of the heat equalization layer (2). The outer elastic diaphragm (3012) is a fluorosilicone rubber sheet.

8. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 7, characterized in that: The elastomeric energy storage bladder (303) has a sleeve (304) and a rod (305) inside, and the sleeve (304) and the rod (305) are sleeved and connected, and an energy storage spring (306) is provided in the sleeve space of the sleeve (304) and the rod (305).

9. The high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 1, characterized in that: The outer surface of the heat-uniforming layer (2) and the inner wall of the pressure self-compensation layer (3) are both treated with plasma and coated with a silane coupling agent primer layer.

10. A high-temperature resistant liquid silicone composite longitudinal tension roller according to claim 1, characterized in that: The heat-resistant silicone layer (4) is wrapped around the outer surface of the pressure self-compensating layer (3). The heat-resistant silicone layer (4) is composed of addition-type liquid silicone rubber doped with composite heat-resistant filler and release agent. The composite heat-resistant filler is a mixture of iron oxide, cerium oxide and hexagonal boron nitride. The release agent is trifluoropropylmethylcyclotrisiloxane homopolymer. The heat-resistant silicone layer (4) contains irreversible thermochromic particles.

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