Surface coating reconstruction system and method for calendering roller

Abstract

The invention relates to the field of calendaring machines, in particular to a surface coating reconstruction system and method for a calendaring roller, and the system integrates an industrial robot and is equipped with two functional C-shaped mechanical arms, namely a coating C-shaped mechanical arm and a stripping C-shaped mechanical arm. Wherein the coating C-shaped mechanical arm carries an atmosphere plasma torch, a precise slit coating head and an LED-UV curing lamp holder array and is used for preparing a new coating; the stripping C-shaped mechanical arm carries a laser scribing unit, a blowing stripping unit and a mechanical traction unit and is used for removing an old coating. According to the embodiment of the invention, an old coating can be rapidly and completely stripped, chemical solvent or mechanical damage is avoided, an ideal substrate is created for subsequent coating reconstruction, a seamless coating with uniform thickness and strong binding force can be generated, the reliability and the service life of the coating are superior to those of a traditional isolating membrane, and the downtime of equipment is remarkably shortened.

Description

Technical Field

[0001] This invention relates to the field of calendering mills, and more specifically to a surface coating reconstruction system for calendering rolls.

[0002] The present invention also relates to a surface coating reconstruction method performed by a surface coating reconstruction system. Background Technology

[0003] Calendering is a key process that involves extruding and stretching polymer materials (such as rubber and plastic) between two or more counter-rotating rollers to produce films or sheets with specific thicknesses and surface qualities.

[0004] In some demanding applications, such as the vulcanization system of addition-cure fluorosilicone rubber, which relies on platinum catalysts, these catalysts are highly susceptible to reacting with active metal ions precipitated on the surface of the calender's metal rollers. This can lead to catalyst "poisoning" and failure, resulting in incomplete curing of the rubber compound and serious quality defects such as gel particles, surface pitting, and uneven thickness, ultimately leading to product scrap.

[0005] To address this technical challenge, existing technologies primarily employ a membrane-adhesive method: a layer of PTFE tape is adhered to the surface of a standard metal roller to physically isolate the catalyst. While this method alleviates catalyst poisoning to some extent, it suffers from significant drawbacks, including easy damage to the membrane, impact on product quality at seams, frequent replacement and maintenance requiring manual operation, and low production efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a surface coating reconstruction system and method for calendering rolls, aiming to solve the problems of poor reliability and low maintenance efficiency of the isolation layer of calendering rolls in the prior art, and to achieve an automated, efficient and high-quality technical solution for in-service coating preparation and renewal.

[0007] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A surface coating reconstruction system for calendering rolls includes an industrial robot and its carried coating C-arm and peeling C-arm; The coated C-shaped robotic arm is equipped with: An atmospheric plasma torch is used to clean and activate the surface of the calender rolls; A precision slit coating head is used to coat liquid resin onto the surface of the calendering roll in the form of a uniform liquid film. An array of LED-UV curing lamp heads is used to cure the liquid film to form a coating; The C-shaped robotic arm for stripping is equipped with: A laser scribing unit is used to scribble an initial cut on the coating; An air-blowing peeling unit is used to inject high-pressure gas below the initial cut to lift the edge of the coating; A mechanical traction unit is used to completely peel off and wind the coating at a speed strictly synchronized with the rotational linear speed of the calendering roll after the edge of the coating is lifted.

[0008] Furthermore, the atmospheric plasma torch includes a large-format plasma generator, a gas delivery system, and a nozzle, and the industrial robot is used to control the relative position and movement trajectory of the nozzle of the plasma torch with respect to the surface of the calendering roll.

[0009] Furthermore, the power range of the plasma generator is 200-1000W, the frequency is 15-40kHz, and the gas delivery system delivers compressed air to the jet head at a flow rate of 10-50L / min.

[0010] Furthermore, the slit coating head is connected to the coating C-shaped robotic arm via a radial movement device, thereby controlling the gap between the slit coating head and the calender roller surface to be 20-200 micrometers.

[0011] Furthermore, the wavelength emitted by the LED-UV curing lamp array matches the absorption wavelength of the photoinitiator in the liquid resin, and the peak irradiance of the LED-UV curing lamp array is 1-10 W / cm², with an exposure time of 0.1-2 seconds.

[0012] Furthermore, the laser scribing unit includes a laser, a two-dimensional galvanometer scanning head, and a linear driver; the linear driver is used to drive the laser to move along a direction parallel to the axis of the calendering roll; the two-dimensional galvanometer scanning head is used to eliminate the circumferential movement distance between the calendering roll and the laser during the rotation of the calendering roll.

[0013] Furthermore, the air-blowing stripping unit includes at least one high-pressure gas nozzle, the nozzle orifice of which faces the starting cut and is adjusted by a rotary driver to form an acute angle with the roller surface.

[0014] Furthermore, the mechanical traction unit includes a take-up roller and a floating cover; the floating cover is disposed on the outside of the take-up roller, and a cylindrical gap is formed between them; an opening is provided on one side of the floating cover, and a guide plate extends from the opening, the guide plate being close to the calendering roller, the guide plate being used to guide the coating into the gap after the coating edge is lifted; the two ends of the floating cover are connected to the peeling C-shaped robotic arm by elastic springs or universal joints so that it can float radially adaptively, so that the gap between the floating cover and the take-up roller can accommodate the coating gradually wound on the take-up roller.

[0015] A surface coating reconstruction method performed by a surface coating reconstruction system includes the following steps: Move the stripping C-shaped robotic arm to the side of the calendering roll; The laser scribing unit is activated to scribble an initial cut on the coating. The air-blowing peeling unit is activated to inject high-pressure gas below the initial cut to lift the edge of the coating. The mechanical traction unit is activated to peel the existing coating off the surface of the calendering roll; Move the coating C-shaped robotic arm to the side of the calendering roll; The atmospheric plasma torch is activated to clean and activate the surface of the calendering rolls; The precision slit coating head is activated to coat the liquid resin at a flow rate synchronized with the linear speed of the calendering roller rotation; The LED-UV curing lamp array is activated to cure the liquid film.

[0016] Furthermore, the liquid resin comprises the following components in parts by weight: UV-curable polyurethane acrylate: 60-75 parts; Micron-sized polytetrafluoroethylene powder: 15-25 parts; Photoinitiator: 1-3 parts; Organosilicon-modified acrylate: 5-10 parts.

[0017] The advantages of this invention compared to the prior art are as follows: The embodiments of the present invention employ a series of precision processes such as plasma pretreatment, slot coating, and UV in-situ curing to form a seamless, uniformly thick, and well-bonded functional coating that adheres well to the roller substrate. Its reliability and service life are superior to traditional adhesive release films, significantly reducing equipment downtime and maintenance time and improving the overall operating efficiency of the production line.

[0018] The embodiments of the present invention achieve rapid and complete peeling of the old coating through the synergistic effect of laser scribing, high-pressure gas and mechanical traction, avoiding damage to the roller body caused by chemical solvents or mechanical grinding, and creating ideal substrate conditions for the next coating reconstruction.

[0019] The embodiments of the present invention, through a modular C-shaped robotic arm design, enable the system to flexibly switch between different rollers of a multi-roll calender, adapting to the maintenance needs of rollers of different sizes and positions. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0021] Figure 1 This is a perspective view of the coated C-shaped robotic arm according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the working state of the coated C-shaped robotic arm according to an embodiment of the present invention; Figure 3 This is a perspective view of the peeling C-shaped robotic arm according to an embodiment of the present invention; Figure 4 This is a cross-sectional view of the working state of the peeling C-shaped robotic arm according to an embodiment of the present invention; The labels in the diagram represent the following: 1-Coating C-type robotic arm; 11-Plasma generator; 12-Gas delivery system; 13-Injector head; 14-Precision slit coating head; 15-Radial movement device; 16-LED-UV curing lamp array; 2-Peeling C-type robotic arm; 21-Two-dimensional galvanometer scanning head; 22-Linear actuator; 23-High-pressure gas nozzle; 24-Rotary actuator; 25-Take-up roller; 26-Floating cover; 27-Guide plate; 28-Elastic spring; 3-Caulking roller; 31-Coating. Detailed Implementation

[0022] 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.

[0023] Referring to the embodiments, the present invention provides a surface coating reconstruction system for calendering rolls, which includes an industrial robot, a coating C-shaped robotic arm 1 and a peeling C-shaped robotic arm 2.

[0024] An industrial robot (not shown in the figure) serves as an execution platform, capable of selectively grasping the coating C-arm 1 or the peeling C-arm 2 via a quick-change device at its end, and precisely moving it to the side of the calendering roll 3 to be processed on the calendering machine.

[0025] This design allows the coating and peeling functions to be reused on the same industrial robot in a time-sharing manner, optimizing equipment layout and cost.

[0026] The coating C-type robotic arm 1 is an execution unit that integrates all the functions required for coating 31 preparation.

[0027] refer to Figure 1 and Figure 2 The coating C-type robotic arm 1 is equipped with a roller surface pretreatment module for cleaning and activating the surface of the calendering roller 3; a liquid resin coating module for uniformly coating the functional liquid resin onto the roller surface; and an online curing module for rapidly curing the liquid film.

[0028] The peeling C-arm 2 is an execution unit specifically designed to remove the old coating 31.

[0029] refer to Figure 3 and Figure 4 The C-shaped robotic arm 2 is equipped with a coating 31 peeling module, which can efficiently and completely peel the cured coating 31 from the surface of the calendering roller 3.

[0030] To ensure good wettability and adhesion of the liquid resin to the surface of the metal roller, atmospheric pressure glow discharge technology is preferred for the roller surface pretreatment module.

[0031] refer to Figure 2 The roller surface pretreatment module includes an atmospheric plasma torch.

[0032] The atmospheric plasma torch consists of a large-format plasma generator 11, a gas delivery system 12, and a nozzle 13. During operation, an industrial robot controls the nozzle 13 of the atmospheric plasma torch to maintain a set distance (e.g., 5-15 mm) from the surface of the calendering roll 3, and performs scanning motion along the axial and circumferential directions of the roll, thereby treating the entire surface of the roll.

[0033] Specifically, the power range of the plasma generator 11 can be set to 200-1000W, and the frequency to 15-40kHz. The gas delivery system 12 delivers the working gas (usually clean, dry compressed air) to the nozzle 13 at a flow rate of 10-50L / min to generate low-temperature plasma. This plasma can effectively remove organic contaminants from the roller surface and introduce oxygen-containing polar groups, thereby significantly improving the surface's hydrophilicity and activity.

[0034] The core of the liquid resin coating module is a slit coating head, which is supported and positioned by a radial movement device 15 (e.g., a precision linear slide driven by a stepper motor). The function of the radial movement device 15 is to precisely control the gap between the outlet of the slit coating head and the surface of the calendering roller 3. The gap is typically set between 20 and 200 micrometers, which is a key process parameter for forming a thin and uniform liquid film.

[0035] To achieve precise control of the coating thickness 31, the liquid resin coating module also includes a high-precision metering pump (not shown, such as a servo gear pump).

[0036] The metering pump draws liquid resin from the storage tank and delivers it to the slot coating head at a stable flow rate. Furthermore, the feed flow rate of the metering pump and the rotational linear speed of the calendering roller 3 at the coating position are precisely synchronized by the central controller to ensure a constant amount of resin coated per unit area, thereby guaranteeing the uniformity of the final coating thickness 31.

[0037] The online curing module is used to rapidly cure the liquid film coated on the surface of the roller. The module preferably includes an LED-UV curing lamp array 16.

[0038] The LED-UV curing lamp array 16 emits ultraviolet light of a specific wavelength, which matches the absorption wavelength of the photoinitiator in the liquid resin formulation (e.g., 365nm, 395nm, etc.) to achieve efficient energy utilization and curing reaction.

[0039] To ensure that the liquid film can be completely cured during the short period of rotation of the calendering roller 3, the LED-UV curing lamp array 16 is designed to have a high irradiance, with a peak irradiance of 1-10 W / cm² on the roller surface.

[0040] By adjusting the distance between the lamp array and the roller surface, as well as the rotation speed of the roller, the exposure time can be controlled within the range of 0.1-2 seconds to ensure that the coating 31 is fully cured and forms stable physicochemical properties.

[0041] The coating 31 stripping module is designed to completely remove old or damaged coating 31 without damaging the calender roll 3 substrate.

[0042] refer to Figure 4 The coating 31 peeling module integrates three working units: a laser scribing unit, an air-blowing peeling unit, and a mechanical traction unit.

[0043] The function of the laser scribing unit is to create a starting cut on the coating 31 to be peeled off. The laser scribing unit includes a laser (e.g., a fiber laser or a semiconductor laser), a two-dimensional galvanometer scanning head 21, and a linear driver 22. The linear driver 22 is responsible for driving the entire laser head (including the laser and the galvanometer) to move along the axis parallel to the calendering roller 3. During the scribing process, the calendering roller 3 is rotating.

[0044] In order to draw a straight line segment parallel to the roller axis on the rotating curved surface as the starting cut, the two-dimensional galvanometer scanning head 21 will perform dynamic compensation scanning. Its scanning motion is used to eliminate the circumferential movement distance between the calendering roller 3 and the laser during the rotation of the calendering roller 3. By precisely controlling the laser power, scanning speed and focusing position, it can be ensured that the cut only cuts through the thickness of the coating 31 without damaging the roller substrate.

[0045] After the laser scribing unit forms the initial cut, the downstream air-blowing peeling unit begins to operate. The air-blowing peeling unit includes at least one high-pressure gas nozzle 23, whose nozzle faces the initial cut and is adjusted by a rotary driver 24 to form an acute angle with the roller surface. The nozzle injects high-pressure gas (e.g., compressed air at 0.3-0.8 MPa) below the initial cut. The gas expands rapidly at the interface between the coating 31 and the roller, forming an air cushion. The resulting peeling force lifts the edge of the coating 31 from the roller surface, preparing for subsequent mechanical traction.

[0046] Once the edge of coating 31 is lifted, the mechanical traction unit intervenes to completely peel coating 31 off the roller surface and rewind it. The mechanical traction unit includes a take-up roller 25 driven by a motor and a floating cover 26 fitted outside. A cylindrical gap is formed between the floating cover 26 and the take-up roller 25. An opening is provided on one side of the floating cover 26, and a guide plate 27 extends from the opening.

[0047] During operation, the guide plate 27 is positioned close to the calendering roller 3. When the edge of the coating 31 is lifted by the high-pressure gas, it is first captured by the guide plate 27 and guided into the gap between the take-up roller 25 and the floating cover 26. Subsequently, the take-up roller 25 begins to rotate, and its linear speed is strictly synchronized with the rotational linear speed of the calendering roller 3, thereby continuously pulling and winding the coating 31 onto the take-up roller 25.

[0048] As the thickness of the wound coating 31 increases, the design of the floating cover 26 allows it to float radially adaptively, meaning it can move away from the center of the take-up roller 25 within a certain range. This characteristic allows the gap between the floating roller and the take-up roller 25 to increase dynamically, thereby accommodating the coating 31 that is gradually wound onto the take-up roller 25 and ensuring the smooth progress of the entire peeling process.

[0049] The floating cover 26 can be made to float in a variety of ways. For example, the two ends of the floating cover 26 are connected to the peeling C-shaped robotic arm 2 through two elastic springs 28 or two universal joints, so that the floating cover 26 can float up and down to a certain extent.

[0050] In one embodiment for addition-cure fluorosilicone rubber calendering, the resin may be composed of the following components in parts by mass: Main resin: UV-curable polyurethane acrylate (PUA), 60-75 parts; Functional filler: Polytetrafluoroethylene (PTFE) micro powder, 15-25 parts; Photoinitiator: 1173 or TPO, 1-3 parts; Adhesion promoter / peeling aid: silicone-modified acrylate, 5-10 parts.

[0051] Among them, PUA provides the flexibility and abrasion resistance required for coating 31; PTFE micro powder reduces the surface energy of coating 31, providing good isolation and anti-adhesion properties; silicone-modified acrylate enhances the adhesion of coating 31 to the metal substrate, while also enabling coating 31 to maintain a certain toughness and integrity during peeling, making it easy to peel off in whole pieces.

[0052] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered as falling within the scope of protection of the embodiments of the present invention.

Claims

1. A surface coating reconstruction system for calendering rolls, characterized in that, Including industrial robots, and their carried coating C-arms (1) and peeling C-arms (2); The coated C-shaped robotic arm (1) is equipped with: An atmospheric plasma torch is used to clean and activate the surface of the calender roll (3); A precision slit coating head (14) is used to coat the surface of the calendering roll (3) with liquid resin in the form of a uniform liquid film; An LED-UV curing lamp array (16) is used to cure the liquid film to form a coating (31). The stripping C-shaped robotic arm (2) is equipped with: A laser scribing unit is used to scribble an initial cut on the coating (31); A blow-off stripping unit is used to inject high-pressure gas below the initial cut to lift the edge of the coating (31); A mechanical traction unit is used to completely peel off and roll up the coating (31) after the edge of the coating (31) is lifted, at a speed strictly synchronized with the rotational linear speed of the calendering roll (3).

2. The surface coating reconstruction system according to claim 1, characterized in that, The atmospheric plasma torch includes a large-format plasma generator (11), a gas delivery system (12), and a nozzle (13). The industrial robot is used to control the relative position and movement trajectory of the nozzle (13) of the plasma torch with respect to the surface of the calendering roller (3).

3. The surface coating reconstruction system according to claim 2, characterized in that, The plasma generator (11) has a power range of 200-1000W and a frequency of 15-40kHz. The gas delivery system (12) delivers compressed air to the nozzle (13) at a flow rate of 10-50L / min.

4. The surface coating reconstruction system according to claim 1, characterized in that, The slit coating head is connected to the coating C-shaped robotic arm (1) via a radial moving device (15), thereby controlling the gap between the slit coating head and the surface of the calendering roller (3) to be 20-200 micrometers.

5. The surface coating reconstruction system according to claim 1, characterized in that, The wavelength emitted by the LED-UV curing lamp array (16) matches the absorption wavelength of the photoinitiator in the liquid resin. The peak irradiance of the LED-UV curing lamp array (16) is 1-10 W / cm², and the exposure time is 0.1-2 seconds.

6. The surface coating reconstruction system according to claim 1, characterized in that, The laser scribing unit includes a laser, a two-dimensional galvanometer scanning head (21), and a linear driver (22); the linear driver (22) is used to drive the laser to move along the axis parallel to the calendering roller (3); the two-dimensional galvanometer scanning head (21) is used to eliminate the circumferential movement distance between the calendering roller (3) and the laser during the rotation of the calendering roller (3).

7. The surface coating reconstruction system according to claim 1, characterized in that, The air-blowing stripping unit includes at least one high-pressure gas nozzle (23) with its nozzle orifice facing the starting cut and adjusted by a rotary driver (24) to form an acute angle with the roller surface.

8. The surface coating reconstruction system according to claim 1, characterized in that, The mechanical traction unit includes a take-up roller (25) and a floating cover (26); the floating cover (26) is disposed on the outside of the take-up roller (25), and a cylindrical gap is formed between them; an opening is provided on one side of the floating cover (26), and a guide plate (27) extends from the opening. The guide plate (27) is close to the calendering roller (3), and the guide plate (27) is used to guide the coating (31) into the gap after the edge of the coating (31) is lifted; the two ends of the floating cover (26) are connected to the peeling C-shaped robotic arm (2) by elastic springs (28) or universal joints so that it can float radially adaptively, so that the gap between the floating cover (26) and the take-up roller (25) can accommodate the coating (31) gradually wound on the take-up roller (25).

9. A surface coating reconstruction method performed by the surface coating reconstruction system according to any one of claims 1-8, characterized in that, Includes the following steps: Move the stripping C-shaped robotic arm (2) to the side of the calendering roller (3); The laser scribing unit is activated to scribble an initial cut on the coating (31); The air-blowing stripping unit is activated to inject high-pressure gas below the initial cut to lift the edge of the coating (31); The mechanical traction unit is activated to peel off the existing coating (31) from the surface of the calendering roll (3); Move the coating C-shaped robotic arm (1) to the side of the calendering roller (3); The atmospheric plasma torch is activated to clean and activate the surface of the calendering roll (3); Start the precision slit coating head (14) to coat the liquid resin at a flow rate synchronized with the rotational linear speed of the calendering roller (3); The LED-UV curing lamp array (16) is activated to cure the liquid film.

10. The surface coating reconstruction method according to claim 9, characterized in that, The liquid resin comprises the following components in parts by weight: UV-curable polyurethane acrylate: 60-75 parts; Micron-sized polytetrafluoroethylene powder: 15-25 parts; Photoinitiator: 1-3 parts; Organosilicon-modified acrylate: 5-10 parts.

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