A surface coating reprofiling system and method for a calender roll

Abstract

The present application relates to the field of calender, in particular to a surface coating reconstruction system and method of calender roll, the system integrates an industrial robot, and is equipped with two functional C type mechanical arms: coating C type mechanical arm and stripping C type mechanical arm. Among them, the coating C type mechanical arm is equipped with atmospheric plasma torch, precision slit coating head, LED-UV curing lamp head array, and is used for preparation of new coating; the stripping C type mechanical arm is equipped with: laser scribing unit, blowing stripping unit, mechanical traction unit, and is used for removal of old coating. The embodiment of the present application can quickly and completely strip the old coating, avoids chemical solvent or mechanical damage, creates an ideal substrate for subsequent coating reconstruction, and can generate a jointless, uniform thickness, strong bonding coating, which has better reliability and service life than traditional isolation film, and significantly shortens the equipment downtime.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of calendering machines, in particular to a surface coating reconstruction system of a calendering roll.

[0002] The present application also relates to a surface coating reconstruction method performed by the surface coating reconstruction system. BACKGROUND

[0003] Calendering is a key process for producing films or sheets with specific thickness and surface quality by extruding and stretching high molecular materials (such as rubber and plastic) in the gap between two or more counter-rotating rolls.

[0004] In some high-demand application scenarios, for example, the vulcanization system of addition-type fluorosilicone rubber relies on platinum catalyst, which is extremely susceptible to reaction with active metal ions precipitated from the surface of the calendering machine metal roll, resulting in catalyst "poisoning" failure, which can cause incomplete curing of the rubber compound, resulting in serious quality defects such as gel particles, surface pitting, uneven thickness, and ultimately leading to product scrap.

[0005] To solve this technical problem, the existing technology mainly adopts the scheme of pasting a separation film: a layer of PTFE tape is pasted on the surface of the ordinary metal roll to achieve physical isolation of the rubber compound. Although this scheme solves the problem of catalyst poisoning to some extent, it has significant defects such as easy damage to the separation film, impact on product quality at the joint, frequent replacement and maintenance, dependence on manual operation, and low production efficiency. SUMMARY

[0006] The present application aims to provide a surface coating reconstruction system and method for calendering rolls, which aims to solve the problems of poor reliability and low maintenance efficiency of the isolation layer of the calendering roll in the prior art, and to realize an automatic, efficient, and high-quality technical solution for in-service coating preparation and updating.

[0007] To solve the above technical problems, the present application specifically provides the following technical solutions:

[0008] A surface coating reconstruction system for calendering rolls, comprising an industrial robot, and a coating C-type mechanical arm and a stripping C-type mechanical arm carried by the industrial robot;

[0009] The coating C-type mechanical arm is equipped with:

[0010] a large atmospheric plasma torch for cleaning and activating the surface of the calendering roll;

[0011] a precision slot coating head for coating liquid resin in the form of a uniform liquid film on the surface of the calendering roll;

[0012] an array of LED-UV curing lamp heads for curing the liquid film to form a coating;

[0013] The stripping C-type mechanical arm is equipped with:

[0014] a laser scribing unit for scribing a starting cut on the coating layer;

[0015] a blowing stripping unit for injecting high-pressure gas under the starting cut to lift the edge of the coating layer;

[0016] a mechanical traction unit for completely stripping and winding the coating layer at a speed strictly synchronized with the linear speed of the rotating roll after the edge of the coating layer is lifted.

[0017] Further, the atmospheric plasma torch includes a large-area plasma generator, a gas delivery system, and a spray head, and the industrial robot is used to control the relative position and movement trajectory of the spray head of the plasma torch and the surface of the calender roll.

[0018] Further, the power of the plasma generator ranges from 200 to 1000 W, and the frequency ranges from 15 to 40 kHz, and the gas delivery system delivers compressed air to the spray head at a flow rate of 10-50 L / min.

[0019] Further, the slot coating head is connected to the coating C-type mechanical arm through a radial movement device, so as to control the gap between the slot coating head and the surface of the calender roll to be 20-200 microns.

[0020] Further, the wavelength emitted by the LED-UV curing lamp head array matches the absorption wavelength of the photoinitiator in the liquid resin, the peak irradiance of the LED-UV curing lamp head array is 1-10 W / cm², and the exposure time is 0.1-2 seconds.

[0021] Further, 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 the axis direction parallel to the calender roll; and the two-dimensional galvanometer scanning head is used to eliminate the circumferential movement distance of the calender roll and the laser during the rotation of the calender roll.

[0022] Further, the blowing stripping unit includes at least one high-pressure gas nozzle, the nozzle of the high-pressure gas nozzle is directed towards the starting cut, and is adjusted by a rotary driver to form an acute angle with the roll surface.

[0023] Further, the mechanical traction unit comprises a winding roller and a floating shell; the floating shell is arranged outside the winding roller, and a cylindrical gap is formed between the two; one side of the floating shell is provided with an opening, the opening extends a guide plate, the guide plate is close to the calender roller, and the guide plate is used to guide the coating into the gap after the coating edge is lifted; the two ends of the floating shell are connected with the stripping C-shaped mechanical arm through elastic spring sheets or universal joints to enable the floating shell to radially self-adaptively float, so that the gap between the floating shell and the winding roller can accommodate the coating gradually wound on the winding roller.

[0024] A surface coating reconstruction method performed by a surface coating reconstruction system, comprising the following steps:

[0025] Moving the stripping C-shaped mechanical arm to the side of the calender roller;

[0026] Starting the laser scribing unit to scribe a starting incision on the coating;

[0027] Starting the blowing stripping unit to inject high-pressure gas below the starting incision to lift the coating edge;

[0028] Starting the mechanical traction unit to strip the existing coating from the surface of the calender roller;

[0029] Moving the coating C-shaped mechanical arm to the side of the calender roller;

[0030] Starting the atmospheric plasma torch to clean and activate the surface of the calender roller;

[0031] Starting the precision slot coating head to coat the liquid resin at a flow rate synchronized with the rotational linear speed of the calender roller;

[0032] Starting the LED-UV curing lamp head array to cure the liquid film.

[0033] Further, the liquid resin comprises the following components in mass fraction:

[0034] Ultraviolet light-curable polyurethane acrylate: 60-75 parts;

[0035] Micron-sized polytetrafluoroethylene powder: 15-25 parts;

[0036] Photoinitiator: 1-3 parts;

[0037] Silicone-modified acrylate: 5-10 parts.

[0038] The present application has the following beneficial effects compared with the prior art:

[0039] The embodiment of the present application adopts a series of precise processes such as plasma pretreatment, slit coating and UV in-situ curing, can form a functional coating layer without joint, with high uniformity in thickness and good combination with the roller base, has higher reliability and service life than the traditional pasted isolation film, significantly shortens the equipment downtime maintenance time, and improves the operation efficiency of the overall production line.

[0040] The embodiment of the present application realizes rapid and complete peeling of the old coating layer through the synergistic effect of laser scribing, high-pressure gas and mechanical traction, avoids damage to the roller body caused by chemical solvents or mechanical polishing, and creates ideal substrate conditions for the next coating reconstruction.

[0041] The embodiment of the present application realizes the flexible switching of the system between different rollers of the multi-roller calender through the modular C-shaped mechanical arm design, and adapts to the roller maintenance requirements of different sizes and positions. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only exemplary, and other implementation drawings can be obtained according to the provided drawings without creative labor for those skilled in the art.

[0043] Figure 1 It is a perspective view of the coating C-shaped mechanical arm of the embodiment of the present application;

[0044] Figure 2 It is a sectional view of the working condition of the coating C-shaped mechanical arm of the embodiment of the present application;

[0045] Figure 3 It is a perspective view of the peeling C-shaped mechanical arm of the embodiment of the present application;

[0046] Figure 4 It is a sectional view of the working condition of the peeling C-shaped mechanical arm of the embodiment of the present application;

[0047] The numbers in the figures respectively represent as follows:

[0048] 1-coating C-shaped mechanical arm; 11-plasma generator; 12-gas delivery system; 13-jet head; 14-precision slit coating head; 15-radial movement device; 16-LED-UV curing lamp head array; 2-peeling C-shaped mechanical arm; 21-two-dimensional galvanometer scanning head; 22-linear driver; 23-high-pressure gas nozzle; 24-rotary driver; 25-winding roller; 26-floating shell; 27-guide plate; 28-elastic spring; 3-calender roller; 31-coating layer. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0050] With reference to the embodiments, the present application provides a surface coating reconstruction system of a calender roll, which comprises an industrial robot, a coating C-type mechanical arm 1 and a stripping C-type mechanical arm 2.

[0051] The industrial robot (not shown in the figure) serves as an execution platform, and can selectively grab the coating C-type mechanical arm 1 or the stripping C-type mechanical arm 2 through a quick-change device at the tail end thereof, and accurately move the same to the side of the calender roll 3 to be processed on the calender.

[0052] This design enables the coating and stripping functions to time-share the same industrial robot, thereby optimizing the equipment layout and cost.

[0053] The coating C-type mechanical arm 1 is an execution unit integrating all functions required for preparation of a coating 31.

[0054] Referring to Figure 1 and Figure 2 , the coating C-type mechanical arm 1 is provided with a roll surface pretreatment module for cleaning and activating the surface of the calender roll 3, a liquid resin coating module for uniformly coating a functional liquid resin on the roll surface, and an online curing module for rapidly curing the liquid film into a shape.

[0055] The stripping C-type mechanical arm 2 is an execution unit specially used for removing the old coating 31.

[0056] Referring to Figure 3 and Figure 4 , the stripping C-type mechanical arm 2 is provided with a coating 31 stripping module capable of efficiently and completely stripping the cured coating 31 from the surface of the calender roll 3.

[0057] In order to ensure that the liquid resin has good wettability and adhesion on the surface of the metal roll, the roll surface pretreatment module preferably adopts an atmospheric pressure glow discharge technology.

[0058] Referring to Figure 2 , the roll surface pretreatment module comprises an atmospheric plasma torch.

[0059] The atmospheric plasma torch is composed of a large-area plasma generator 11, a gas delivery system 12 and a spray head 13; in operation, the industrial robot controls the spray head 13 of the atmospheric plasma torch to maintain a set distance (e.g. 5-15 mm) from the surface of the calender roll 3 and to perform scanning motion along the axial and circumferential direction of the roll, thereby treating the entire roll surface.

[0060] Specifically, the power range of the plasma generator 11 can be set to 200-1000 W, and the frequency is 15-40 kHz. The gas delivery system 12 delivers the working gas (usually clean and dry compressed air) to the spray head 13 at a flow rate of 10-50 L / min to generate low-temperature plasma. This plasma can effectively remove organic contaminants on the roll surface and introduce oxygen-containing polar groups, thereby significantly improving the hydrophilicity and activity of the surface.

[0061] The core of the liquid resin coating module is a slit coating head, which is supported and positioned by a radial moving device 15 (e.g. a precision linear slide driven by a stepper motor), which precisely controls the gap between the outlet of the slit coating head and the surface of the calender roll 3. The gap is usually set to be in the range of 20-200 microns, which is a key process parameter for forming a thin and uniform liquid film.

[0062] In order to achieve precise control of the thickness of the coating 31, the liquid resin coating module further includes a high-precision metering pump (not shown, e.g. a servo gear pump).

[0063] The metering pump draws liquid resin from the storage tank and delivers it to the slit coating head at a stable flow rate. The feed flow rate of the metering pump is precisely synchronized with the linear speed of the rotating calender roll 3 at the coating position through the central controller, ensuring that the amount of resin coated per unit area is constant, thereby ensuring the uniformity of the final coating 31 thickness.

[0064] The online curing module is used to quickly cure the liquid film coated on the roll surface, and the module preferably includes an LED-UV curing lamp head array 16.

[0065] The LED-UV curing lamp head array 16 emits ultraviolet light of a specific wavelength that matches the absorption wavelength of the photoinitiator in the liquid resin formulation (e.g. 365 nm, 395 nm, etc.), to achieve high energy utilization and curing reaction efficiency.

[0066] In order to ensure that the liquid film can be completely cured within the short time of the rotation of the calender roll 3, the LED-UV curing lamp head array 16 is designed to have a high irradiance, with a peak irradiance on the roll surface of 1-10 W / cm².

[0067] By adjusting the distance between the lamp head array and the surface of the roller and the rotation speed of the roller, the exposure time can be controlled in the range of 0.1-2 seconds, ensuring that the coating 31 is sufficiently cured to form stable physical and chemical properties.

[0068] The coating 31 stripping module is designed to completely remove the old or damaged coating 31 without damaging the base of the calender roller 3.

[0069] Reference Figure 4 The coating 31 stripping module integrates three units that work together, namely: a laser scribing unit, a blowing stripping unit, and a mechanical traction unit.

[0070] The function of the laser scribing unit is to make a starting cut on the coating 31 to be stripped. 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 responsible for driving the entire laser head (including the laser and the galvanometer) to move along the direction parallel to the axis of the calender roller 3, and the calender roller 3 is rotating during the scribing process.

[0071] In order to scribe a straight line segment on the rotating curved surface as a starting cut, which is parallel to the axis of the roller, the two-dimensional galvanometer scanning head 21 will perform dynamic compensation scanning, and the scanning motion is used to eliminate the circumferential movement distance of the calender roller 3 and the laser during the rotation of the calender roller 3. By precisely controlling the laser power, scanning speed, and focusing position, it can be ensured that the cut only penetrates the thickness of the coating 31 without damaging the roller base.

[0072] After the laser scribing unit forms the starting cut, the downstream blowing stripping unit begins to work. The blowing stripping unit includes at least one high-pressure gas nozzle 23, the nozzle is directed towards the starting cut, and is adjusted by a rotary driver 24 to form an acute angle with the surface of the roller. The nozzle injects high-pressure gas (e.g., 0.3-0.8 MPa compressed air) below the starting cut, and the gas expands rapidly at the interface between the coating 31 and the roller, forming an air cushion, and the generated stripping force lifts the edge of the coating 31 from the surface of the roller, preparing for the subsequent mechanical traction.

[0073] When the edge of the coating 31 is lifted, the mechanical traction unit intervenes to completely strip the coating 31 from the surface of the roller and wind it up for recycling. The mechanical traction unit includes a winding roller 25 driven by a motor and a floating shell 26 fitted outside, forming a cylindrical gap between the winding roller 25 and the floating shell 26. On one side of the floating shell 26, an opening is provided, and a guide plate 27 extends from the opening.

[0074] When working, the guide plate 27 is positioned close to the calender roller 3, and after 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 winding roller 25 and the floating shell 26, and then the winding roller 25 starts to rotate, with the linear speed strictly synchronized with the linear speed of the rotation of the calender roller 3, so as to continuously pull and wind the coating 31 on the winding roller 25.

[0075] With the increase of the thickness of the wound coating 31, the design of the floating shell 26 enables it to adaptively float radially, that is, it can be away from the center of the winding roller 25 within a certain range, and this feature enables the gap between the floating roller and the winding roller 25 to dynamically increase, thereby being able to accommodate the coating 31 gradually wound on the winding roller 25, ensuring the smooth progress of the entire stripping process.

[0076] The floating shell 26 can have various ways to make itself have the floating performance, for example, the two ends of the floating shell 26 are connected to the stripping C-shaped mechanical arm 2 through two elastic spring sheets 28 or two universal joints, so that the floating shell 26 can float up and down to a certain extent.

[0077] In an embodiment for calendering of addition type fluorosilicone rubber, the resin can be composed of the following components in mass parts:

[0078] Main resin: ultraviolet light curing type polyurethane acrylate (PUA), 60-75 parts;

[0079] Functional filler: polytetrafluoroethylene (PTFE) micro powder, 15-25 parts;

[0080] Photoinitiator: 1173 or TPO, 1-3 parts;

[0081] Adhesion promoter / stripping aid: silicone-modified acrylate, 5-10 parts.

[0082] Among them, the PUA provides the required flexibility and wear resistance of the coating 31; the PTFE micro powder reduces the surface energy of the coating 31, providing good isolation and anti-adhesion properties; the silicone-modified acrylate improves the adhesion of the coating 31 to the metal substrate while also enabling the coating 31 to maintain a certain toughness and integrity during stripping, facilitating the whole piece to be stripped.

[0083] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements are also regarded as falling within the protection scope of the embodiments of the present application.

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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