Manufacturing method of ultra-wide PS plate

Abstract

The invention discloses a method for manufacturing an ultra-wide PS plate, which comprises the following steps of: smelting an aluminum ingot in the range of 700-760 DEG C, and adding an aluminum-titanium alloy in the smelting process to control the titanium content to be 0.005-0.016%; gas and impurities are removed through two times of argon refining, and the refined molten aluminum is transferred into a heat preservation furnace at the temperature of 720-740 DEG C for heat preservation; the molten aluminum enters a cast-rolling area after being subjected to tubular filtration, and a cast-rolling coil with the thickness being 6.3-6.9 mm is formed under the conditions that the temperature is 692-696 DEG C and the cast-rolling speed is 860-900 mm / min; by adding titanium wires at different points and controlling multi-layer temperature, the uniform distribution of the titanium element is ensured; then multi-pass cold rolling and timed standing cooling are carried out, and the thickness is controlled to be 0.8-1.1 mm; and finally, the high-quality PS plate base material is obtained through foil rolling, edge cutting, stretching, weak base cleaning and other processes, according to the method, through fine process control, black strip defects are effectively reduced, and the surface quality and the yield of the PS plate base material are improved.

Description

Technical Field

[0001] The invention relates to a method for manufacturing an ultra-wide PS plate. Background Art

[0002] PS plate is a key material widely used in printing plate making. It is usually made of aluminum-based material. Its surface is pre-coated with photosensitization and can form an image after exposure. With the development of computer typesetting and high-precision printing technology, higher requirements are placed on the surface quality, flatness and organizational structure of the PS plate substrate. However, in the existing PS plate production process, especially in the manufacture of ultra-wide PS plates, there are many difficult-to-solve technical problems, resulting in high production costs and low yields, affecting the competitiveness of the products in the market.

[0003] Among them, the black stripe defect is a prominent problem in PS plate production. Black stripes are usually difficult to detect on the surface of the material and often only appear after acid and alkali cleaning or electrolysis. This defect is caused by the uneven microstructure inside the PS plate substrate, especially in the process of adding and distributing titanium elements. If the titanium element is not fully dissolved or evenly distributed, it is very easy to form aggregates in the aluminum matrix, which leads to black stripes. This defect not only affects the quality of the finished product, but also brings additional costs to the customer in the subsequent processing process, such as increased electrolyte consumption and labor costs, and may even lead to customer claims, causing greater economic losses to manufacturers. Therefore, how to effectively control the addition amount and distribution uniformity of titanium elements to eliminate black stripe defects is a technical problem that needs to be solved urgently.

[0004] In addition, in the existing production process, the temperature and tension control accuracy of key steps such as casting, cold rolling, and foil rolling is not high, which can easily lead to defects such as uneven surface roughness and edge cracks in the finished product. The traditional flow channel heating method usually relies on manual torch heating, which not only has uneven temperature control, but also causes local overheating and even damages the flow channel equipment, increasing the equipment maintenance cost and affecting the stability and efficiency of production.

[0005] Therefore, those skilled in the art need a method for manufacturing an ultra-wide PS plate, which can reduce black stripe defects and other surface defects and improve product yield through refined titanium element control, precise temperature and tension regulation. Summary of the invention

[0006] The purpose of the present invention is to solve the above shortcomings of the prior art and provide a method for manufacturing an ultra-wide PS plate, which reduces the probability of black stripe defects on the PS plate through refined process steps. The following is a specific solution:

[0007] A method for manufacturing an ultra-wide PS plate comprises the following steps: smelting aluminum ingots within a range of 700 to 760°C, adding aluminum-titanium alloy during the smelting process to make the titanium content in the product between 0.005% and 0.016%, removing gas and impurities through two argon refinings, each refining time is 15 to 25 minutes, each refining pressure is 0.2 to 0.5 MPa, after refining, transferring the aluminum liquid to a heat preservation furnace controlled at a temperature of 720 to 740°C for heat preservation; filtering the aluminum liquid through a tubular filter and then flowing it into a casting and rolling zone, controlling the temperature of the casting and rolling zone A cast-rolled coil with a thickness of 6.3 to 6.9 mm is formed at 692 to 696° C. and a casting speed of 860 to 900 mm / min; titanium wire with a temperature range of 720 to 740° C. is added to the cast-rolled coil, and the titanium wire is added at the starting point and the end of the flow channel respectively; multiple cold rolling passes are performed to reduce the thickness to 0.8 to 1.1 mm, and the coil is cooled for 8 to 10 hours between every three cold rolling passes; the semi-finished aluminum strip after cold rolling is trimmed; the strip after trimming is foil rolled; the foil rolled strip is trimmed, stretched and weakly cleaned.

[0008] Using cold rolling work rolls with nanoscale surface coatings, controlling the roll crown and roughness, and applying constant tension during the cold rolling process can reduce the impact of internal stress generated during the rolling process on the plate shape and improve the dimensional accuracy of the strip after cold rolling. The strip is parked and cooled naturally after every three cold rolling passes to release the residual stress inside the strip during the rolling process, ensuring that the strip has a stable structure and good flatness after cold rolling.

[0009] Furthermore, the smelting step includes smelting aluminum ingots at a temperature of 760°C, adding aluminum-titanium alloy during the smelting process to make the titanium content in the product 0.016%, removing gases and impurities through two argon refinings, each refining time is 20 minutes, each refining pressure is 0.3MPa, and after refining, the molten aluminum is transferred to a holding furnace controlled at a temperature of 735°C for insulation; argon refining is used to remove gases and impurities to obtain high-purity aluminum liquid, effectively avoiding the formation of pores and inclusions in the cast and rolled coils, thereby improving the surface quality of the PS substrate, and precise control of the titanium content can avoid black stripe defects caused by the aggregation of titanium elements in the aluminum liquid, and the refined aluminum liquid is kept in the range of 735°C to ensure that the temperature of the aluminum liquid is uniform, thereby providing a stable temperature bar for subsequent casting and rolling operations.

[0010] Furthermore, the titanium wire adding step includes adding titanium wire at a temperature of 730°C, and the titanium wire supply device includes a drive motor with digital control and a left-right swing frequency adjustment system, wherein the left-right swing frequency is automatically adjusted according to the flow channel temperature and the aluminum liquid flow rate to ensure the uniformity of the titanium wire melting.

[0011] Furthermore, the casting step includes filtering the molten aluminum through a tubular filter and then flowing it into the casting zone, controlling the temperature of the casting zone at 696° C., and forming a cast coil with a thickness of 6.6 mm at a casting speed of 900 mm / min.

[0012] Furthermore, the cold rolling step uses a cold rolling work roll with a nanoscale surface coating, whose convexity is between +0.02 and 0.04 mm, and its roughness is controlled to 0.2 to 0.7 μm by fine-tuning, and is parked for 10 hours for natural cooling after every three cold rolling passes. During the parking process, a constant tension of 0.001 MPa is applied to the aluminum strip.

[0013] Furthermore, the semi-finished product trimming of the cold-rolled aluminum strip further includes applying 5% to 10% additional tension to both sides of the strip through an automatic tension control system during trimming. The automatic tension control system is set to apply precise lateral tension during the trimming process, so that both sides of the aluminum strip after trimming are smooth, reducing the occurrence of edge defects, thereby improving the product yield. Applying additional tension to both sides of the strip during trimming can reduce deformation of the strip during the trimming process, so that the strip can maintain higher stability during the subsequent foil rolling process.

[0014] Furthermore, a two-pass continuous rolling method is adopted in the foil rolling step, wherein the rolling speed of each pass is automatically adjusted between 500 and 700 m / min according to the strip temperature feedback signal, the convexity of the working roll is +0.05 to 0.08 mm, and the convexity of the supporting roll is +0.03 to 0.06 mm. The relative position between the supporting roll and the working roll is adjusted by an online micron-level vibration control system to ensure that the plate shape is controlled within the range of -12 to 20I. The relative position between the supporting roll and the working roll is adjusted by the micron-level vibration control system to ensure that the plate shape is controlled within the range of -12 to 20I, effectively avoiding uneven defects in the final product. The vibration control system minimizes the vibration during the rolling process, avoids roller surface wear, ensures long-term stable operation of the roller, and helps to improve production efficiency and reduce maintenance costs.

[0015] Furthermore, the straightening step includes online trimming, stretching and weak alkali cleaning, wherein during the stretching process, a tension with an elongation controlled between 0.2% and 0.5% is applied, and during the weak alkali cleaning, the pH value of the cleaning solution is controlled between 8 and 10. The appropriate elongation applied during the straightening process can straighten the plate shape and ensure the flatness of the strip when it is wound into a finished product. The weak alkali cleaning can effectively remove oil stains and fine particles during the rolling process, keep the surface of the strip clean, and meet the high surface quality requirements of the PS plate.

[0016] Beneficial effects: The present invention effectively reduces the probability of occurrence of black stripe defects in PS plates through refined process steps, and improves the surface quality and yield rate of products; by strictly controlling the titanium content and temperature in the smelting stage, the distribution of titanium in the aluminum matrix is ​​more uniform, avoiding the phenomenon of titanium element aggregation in the aluminum liquid to form black stripes. At the same time, multi-level temperature monitoring and titanium wire point addition process are introduced in the casting and rolling process, so that the titanium wire can be fully dissolved and flow evenly with the aluminum liquid, further reducing the risk of black stripe defects; in the cold rolling and trimming process, by applying precise tension control, it is ensured that the strip maintains flatness and stability during processing, avoiding surface defects caused by uneven stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a process for manufacturing an ultra-wide PS plate;

[0018] Figure 2 It is a schematic diagram of the position of the titanium wire device, wherein 1 is the flow channel, 2 is the titanium wire device at the starting point, and 3 is the titanium wire device at the end. DETAILED DESCRIPTION

[0019] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0020] Please see Figure 1 A method for manufacturing an ultra-wide PS plate comprises the following steps: smelting aluminum ingots in the range of 700 to 760°C, adding aluminum-titanium alloy during the smelting process to make the titanium content in the product between 0.005% and 0.016%, removing gas and impurities through two argon refinings, each refining time is 15 to 25 minutes, each refining pressure is 0.2 to 0.5 MPa, after refining, transferring the aluminum liquid to a holding furnace controlled at a temperature of 720 to 740°C for holding; filtering the aluminum liquid through a tubular filter and then flowing it into a casting and rolling zone, controlling the temperature of the casting and rolling zone The temperature is 692-696°C and the casting speed is 860-900 mm / min to form a cast-rolled coil with a thickness of 6.3-6.9 mm; titanium wires with a temperature range of 720-740°C are added to the cast-rolled coil, and the titanium wires are added at the starting point and the end of the flow channel respectively; multiple cold rolling is performed to reduce the thickness to 0.8-1.1 mm, and the aluminum strip is parked for cooling for 8-10 hours between every three cold rolling passes; the semi-finished aluminum strip after cold rolling is trimmed; the strip after trimming is foil rolled; the foil rolled strip is trimmed, stretched and weakly cleaned.

[0021] The smelting step includes smelting aluminum ingots at a temperature of 760°C, adding aluminum-titanium alloy during the smelting process to make the titanium content in the product 0.016%, and removing gases and impurities through two argon refinings, each refining time is 20 minutes, each refining pressure is 0.3MPa, and after refining, the molten aluminum is transferred to a holding furnace controlled at a temperature of 735°C for insulation.

[0022] The titanium wire adding step includes adding the titanium wire at a temperature of 730°C.

[0023] The casting and rolling step includes filtering the molten aluminum through a tubular filter and then flowing it into the casting and rolling zone, controlling the temperature of the casting and rolling zone at 696° C., and forming a cast and rolling coil with a thickness of 6.6 mm at a casting and rolling speed of 900 mm / min.

[0024] The cold rolling step uses a cold rolling work roll with a nanoscale surface coating, whose convexity is between +0.02 and 0.04 mm. Its roughness is controlled to 0.2 to 0.7 μm through fine-tuning, and it is parked for 10 hours for natural cooling after every three cold rolling passes. During the parking process, a constant tension of 0.001 MPa is applied to the aluminum strip.

[0025] The semi-finished product trimming of the cold-rolled aluminum strip further includes applying 5% to 10% additional tension to both sides of the strip through an automatic tension control system during trimming.

[0026] A two-pass continuous rolling method is adopted in the foil rolling step, wherein the rolling speed of each pass is automatically adjusted between 500 and 700 m / min according to the strip temperature feedback signal, the convexity of the working roll is +0.05 to 0.08 mm, and the convexity of the supporting roll is +0.03 to 0.06 mm. The relative position between the supporting roll and the working roll is adjusted by an online micron-level vibration control system to ensure that the plate shape is controlled within the range of -12 to 20I.

[0027] The straightening step includes online trimming, stretching and weak alkali cleaning, wherein during the stretching process, a tension with an elongation controlled between 0.2% and 0.5% is applied, and during the weak alkali cleaning, the pH value of the cleaning solution is controlled between 8 and 10.

[0028] For the purpose of greater clarity, the invention is described in detail through the following examples.

[0029] In a specific embodiment, the components and mass percentages of the PS plate are: Si 0.02-0.06%, Fe 0.2-0.45%, Cu 0.010-0.02%, Mn≤0.02%, Zn≤0.01%, Ti≤0.016%, and the balance is Al.

[0030] In a specific embodiment, the steps start with melting the aluminum ingot in a melting furnace, the highest melting aluminum water temperature is ≤760°C, the melting furnace temperature is 1050°C, the melting time is ≤12 hours, and appropriate aluminum-titanium alloy is added to the melting furnace to ensure that its titanium content is about 0.005-0.016%; the holding furnace temperature is 720-740°C, the degassing box is 710-740°C, tubular filtration is used, the front box temperature is controlled at 692-696°C, and the titanium wire point temperature monitoring is added. After multiple tests In summary, the final titanium wire point temperature is best controlled between 720-726℃; the melting furnace and the holding furnace are used for degassing and deslagging twice with refining agent, each refining time is 15-25min, argon refining is used, and the refining pressure is 0.2-0.5mpa; the length of the casting and rolling zone is 45-55mm, and the casting and rolling speed is 860-900mm / min, and the cast-rolled coil is about 6.3-6.9mm; the intermediate segregation grade required for the cast-rolled coil is A grade, and the grain size is level one.

[0031] In a specific embodiment, the main defect of the PS plate is that there are black stripes on the aluminum plate after electrolysis. The black stripes are analyzed by EDS electron microscope, and the main component is the aggregation of titanium elements. The main countermeasure to solve the aggregation of titanium elements is to reduce the addition of titanium elements on the one hand, and to fully melt the titanium wire on the other hand; reducing the titanium element mainly controls the addition amount, but the addition amount cannot be too small, otherwise it will lead to coarse grains. Therefore, through field test data collection, it is concluded that the addition amount of titanium elements is controlled between 0.01-0.016%, and the temperature of the front box is reduced to prevent coarse grains; after the temperature of the titanium wire point is monitored, the black stripe curling and the non-black stripe curling are compared. By comparison, the data are as follows: the average temperature of the titanium wire point of the black strip coil is 712.1℃, and the standard deviation is 7.2; the average temperature of the titanium wire point of the non-black strip coil is 720.8℃, and the standard deviation is 5.3. It can be seen that the average temperature of the black strip coil is lower than the average temperature of the titanium wire point, and the temperature difference of the black strip coil fluctuates relatively greatly; the original titanium wire point temperature control process requirement is: 715±10℃, and the process is now adjusted to 720~740℃; in addition, the temperature fluctuation of the titanium wire point is ensured to be within the minimum range; the titanium wire joining point flow channel is insulated with a special customized cover plate throughout the process, and a handle is designed on the cover plate. When cleaning the flow channel, the cover plate is removed by the handle and covered with insulation cotton for insulation;

[0032] In a specific embodiment, please see Figure 2In order to ensure that the titanium wire can be added evenly, the original titanium wire device is increased to two titanium wire devices. The purpose of this is to prevent titanium deposition. One is added at the beginning of the flow channel, and the other is added at the end of the flow channel in two times; the amount added each time is different, but the total amount is guaranteed to be the same; ALTI5B1 is added at the titanium wire adding point 1, and ALTI5B0.2 is added at the titanium wire point 2. The second addition of ALTI5B0.2 is mainly to reduce the addition of B elements, etc. ALTI5B0.2 has the characteristics of relatively low oxidation content and less aggregation, which prevents the pollution of B impurities in the quality of aluminum melt. Double titanium wires are added; the titanium wire device is improved. The titanium wire device consists of a titanium wire bracket, a driving motor, a titanium wire guide tube, a titanium wire left and right swing device, etc. The titanium wire left and right swing device is mainly used to prevent titanium wire deposition and increase fluidity; the titanium wire moves evenly under the fixed frequency drive of the driving motor, and a titanium wire left and right swing device is set at the place where the titanium wire enters the flow channel, so that the titanium wire can melt quickly and flow with the aluminum liquid.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for manufacturing an ultra-wide PS plate, characterized in that: The following steps are involved: Aluminum ingots are melted in the range of 700-760°C, aluminum-titanium alloy is added during the melting process, so that the titanium content in the product is between 0.005% and 0.016%, and gas and impurities are removed by two argon refinings, each refining time is 15-25 minutes, and each refining pressure is 0.2-0.5MPa. After refining, the molten aluminum is transferred to a holding furnace controlled at a temperature of 720-740°C for insulation; the molten aluminum is filtered through a tubular filter and then flows into the casting and rolling area, and the temperature of the casting and rolling area is controlled at 692-696°C. A cast-rolled coil with a thickness of 6.3 to 6.9 mm is formed at a casting speed of 860 to 900 mm / min; titanium wires with a temperature range of 720 to 740°C are added to the cast-rolled coil, and the titanium wires are added at the starting point and the end of the flow channel respectively; multiple cold rolling passes are performed to reduce the thickness to 0.8 to 1.1 mm, and the coil is cooled for 8 to 10 hours between every three cold rolling passes; the semi-finished aluminum strip after cold rolling is trimmed; the strip after trimming is foil rolled; the foil rolled strip is trimmed, stretched and weakly cleaned.

2. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The smelting step includes smelting aluminum ingots at a temperature of 760°C, adding aluminum-titanium alloy during the smelting process to make the titanium content in the product 0.016%, removing gas and impurities through two argon refinings, each refining time is 20 minutes, each refining pressure is 0.3MPa, and after refining, the molten aluminum is transferred to a holding furnace controlled at a temperature of 735°C for insulation.

3. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The titanium wire adding step includes adding titanium wire at a temperature of 730°C.

4. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The casting step includes filtering aluminum liquid through a tubular filter and then flowing it into a casting zone, controlling the temperature of the casting zone at 696° C., and forming a cast coil with a thickness of 6.6 mm at a casting speed of 900 mm / min.

5. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The cold rolling step uses a cold rolling work roll with a nano-scale surface coating, whose convexity is between +0.02 and 0.04 mm, and its roughness is controlled to 0.2 to 0.7 μm by fine-tuning. After every three cold rolling passes, the roll is parked for 10 hours for natural cooling, and a constant tension of 0.001 MPa is applied to the aluminum strip during the parking process.

6. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The semi-finished product trimming of the cold-rolled aluminum strip further includes applying 5% to 10% additional tension to both sides of the strip through an automatic tension control system during trimming.

7. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The foil rolling step adopts a two-pass continuous rolling method, wherein the rolling speed of each pass is automatically adjusted between 500 and 700 m / min according to the strip temperature feedback signal, the crown of the working roll is +0.05 to 0.08 mm, and the crown of the backup roll is +0.03 to 0.06 mm. The relative position between the backup roll and the working roll is adjusted by an online micron-level vibration control system to ensure that the plate shape is controlled within the range of -12 to 20I.

8. The method for manufacturing an ultra-wide PS plate according to claim 1, characterized in that: The straightening step includes online trimming, stretching and weak alkali cleaning, wherein during the stretching process, a tension with an elongation controlled between 0.2% and 0.5% is applied, and during the weak alkali cleaning, the pH value of the cleaning solution is controlled between 8 and 10.

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