Method and apparatus for repairing a blanket

Abstract

The application provides a repairing method and device for a rubber blanket, which comprises the following steps: firstly heating the rubber layer of the screened rubber blanket to 50-70 DEG C and controlling the heating time to be 5-10 minutes, so as to enhance the activity of the molecular chain in the rubber layer, soften and recover the rubber elasticity; firstly cooling the rubber blanket and then firstly stretching the rubber blanket, so as to determine the initial state of the whole rubber blanket after the elasticity recovery; secondly heating and secondly stretching the rubber layer, the supporting layer and the reinforcing layer of the rubber blanket in the initial state, so as to stretch the rubber layer into a plane; and cutting the edge part of the rubber blanket after the second stretching, so as to obtain the final rubber blanket which can be used, thereby converting the abandoned rubber blanket into the qualified rubber blanket which can be continuously used, and reducing the cost of enterprises.

Description

Technical Field

[0001] The present application relates to the field of printing technology, and in particular to a method and device for repairing a rubber blanket. Background Art

[0002] A rubber blanket is an essential consumable in the offset printing process, primarily used to transfer the image from the printing plate to the substrate. Its structure typically consists of an outer rubber layer, an intermediate support layer, and a reinforcement layer, and it exhibits excellent elasticity, pressure resistance, and durability. During the printing process, the rubber blanket applies uniform pressure to the image area to achieve ink transfer. Its surface flatness directly determines the precision and quality of the print. Therefore, the rubber blanket must maintain stable physical properties and surface morphology over long periods of use to meet the requirements of high-precision printing.

[0003] After long-term, high-pressure use, blankets often develop unevenness such as ripples and dents due to aging, uneven stress, or wear on the rubber surface, affecting print quality. To address this issue, the common approach is to simply replace the uneven blanket or trim the uneven portion, then reuse the remaining portion for processing or specific printing needs.

[0004] During the printing process, the pressure on the blanket varies, and the duration of that pressure varies. Therefore, among all blankets with uneven printing surfaces, some may suffer irreversible damage due to excessive pressure on the rubber surface, while others may be reversible due to less pressure. Conventional solutions for blanket unevenness typically involve replacing or cutting the blanket, which undoubtedly increases blanket consumables and production costs. Summary of the Invention

[0005] In view of this, it is necessary to provide a method and device for repairing a rubber blanket that can repair the rubber blanket to reduce the production cost of the enterprise.

[0006] An embodiment of the present application provides a method for repairing a blanket, which is used to restore the elasticity of a blanket having a rebound elasticity greater than 85%, comprising the following steps:

[0007] Providing a rubber blanket damaged by offset printing, wherein the rubber blanket comprises at least a rubber layer, a support layer and a reinforcement layer that are sequentially bonded together;

[0008] Detect and select rubber blankets with a rubber layer resilience greater than 85%;

[0009] The rubber layer on the screened blanket is heated to 50-70°C for the first time, and the heating time is controlled to be 5-10 minutes;

[0010] The blanket after the first heating is cooled to 20° C.-30° C. for a first time for 5-8 minutes, and the rubber layer in the blanket after the first cooling is stretched at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5% for a first time;

[0011] The rubber blanket after the first stretching is heated for a second time to 80-100° C., and the heating time is controlled to be 10-15 minutes. The rubber layer, the support layer and the reinforcement layer in the second heated rubber blanket are stretched together for a second time at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10%.

[0012] The rubber blanket after the second stretching is cooled to room temperature for the second time, and the edge of the rubber blanket after the second stretching is cut.

[0013] In at least one embodiment of the present application, the step of “detecting and screening out rubber blankets having a rubber layer resilience greater than 85%” further includes the following steps:

[0014] Scrub the rubber layer with a brush to remove paper fibers from the rubber layer;

[0015] Spray 30℃-40℃ cleaning liquid on the rubber layer to soften and clean the ink on the rubber layer.

[0016] In at least one embodiment of the present application, the step of “heating the rubber layer on the screened blanket to 50° C.-70° C. for the first time and controlling the heating time to 5-10 minutes” specifically includes the steps of:

[0017] providing a heating device;

[0018] facing or pressing the heating device onto the rubber layer of the blanket;

[0019] The temperature of the heating device is adjusted to 50° C.-70° C., and the opening time of the heating device is adjusted to 5-10 minutes to heat only the softened rubber layer.

[0020] In at least one embodiment of the present application, the heating device is a heating roller or a hot air blower.

[0021] In at least one embodiment of the present application, the step of "cooling the blanket after the first heating to 20° C.-30° C. for a first time for 5-8 minutes, and stretching the rubber layer of the blanket after the first cooling at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5% for a first time" includes the steps of:

[0022] Let the blanket, after the first heating, stand for 2-5 minutes;

[0023] Cooling the blanket after standing still within 3 minutes to obtain a first state of the blanket after cooling;

[0024] The rubber layer of the blanket in the first state is stretched at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5%.

[0025] In at least one embodiment of the present application, the step of “heating the blanket after the first stretching to 80° C.-100° C. for a second time, controlling the heating time to 10-15 minutes, and jointly stretching the rubber layer, the support layer, and the reinforcing layer of the blanket after the second heating at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% for a second time” includes the steps of:

[0026] Within 10-15 minutes, place the first stretched blanket in a heating device and heat it to 80-100°C to heat and soften the rubber layer, support layer, and reinforcement layer simultaneously;

[0027] A clamping device is used to simultaneously clamp the rubber layer and the opposite sides of the reinforcement layer, and simultaneously stretch the rubber layer, the support layer and the reinforcement layer at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10%, so as to straighten the rubber layer, the support layer and the reinforcement layer at the same time.

[0028] In at least one embodiment of the present application, the step of “cooling the blanket after the second stretching to room temperature for a second time and cutting the edge portion of the blanket after the second stretching” includes the steps of:

[0029] Filling the edge of the blanket after the second cooling with adhesive and performing hot pressing operation;

[0030] Cut the cracked part of the edge of the rubber blanket after hot pressing.

[0031] In at least one embodiment of the present application, the step of “cutting the cracked portion of the edge of the blanket after hot pressing” further includes the following steps:

[0032] The resilience of the cut rubber blanket is tested to select qualified rubber blankets.

[0033] A rubber blanket repair device, wherein during the rubber blanket repair process, the rubber blanket repair method according to any one of claims 1 to 8 is applied, comprising:

[0034] A screening mechanism for screening out rubber blankets with a rebound resilience greater than 85%;

[0035] A fixing mechanism for fixing the screened rubber cloth;

[0036] a temperature control mechanism for performing a first heating, a first cooling, a second heating, and a second cooling on the fixed rubber blanket;

[0037] a stretching mechanism, for performing a first stretching on the blanket after the first cooling, and for performing a second stretching on the blanket after the second heating;

[0038] The cutting mechanism is used for cutting the edge of the rubber blanket after the second stretching.

[0039] In at least one embodiment of the present application, the rubber blanket repairing device further includes a hot pressing mechanism, which is used to perform hot pressing on the edges of the cut rubber blanket.

[0040] This application has at least the following beneficial effects:

[0041] This application involves heating the rubber layer of a selected blanket to a temperature of 50°C-70°C for a controlled heating time of 5-10 minutes to enhance the mobility of the molecular chains in the rubber layer, thereby softening and restoring the rubber elasticity. After a first cooling step, the rubber layer is stretched for a first time to determine the initial state of the entire blanket after elastic recovery. In this initial state, the rubber layer, support layer, and reinforcement layer of the blanket are heated and stretched a second time to stretch the rubber layer into a flat surface. The edges of the blanket after the second stretching step are trimmed to obtain a final, usable blanket, thereby converting discarded blankets into qualified, reusable blankets and reducing costs for the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flowchart of a rubber blanket repair method in Example 1 of the present application. DETAILED DESCRIPTION

[0043] The embodiments of the present application will be described below in conjunction with 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.

[0044] It should be noted that when a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "back", and similar expressions used herein are for illustrative purposes only.

[0045] The following embodiments of the present application are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0046] To facilitate understanding of the technical solution of this application, the rubber blanket involved in this application is widely used in the offset printing process and is the main contact medium between the printing press and the paper. Its main function is to transfer ink from the printing plate to the paper to ensure print quality.

[0047] Specifically, rubber blanket, also known as printing rubber blanket, is a soft material designed specifically for offset printing. Its main function is to serve as a printing substrate, come into direct contact with ink and transfer ink to paper.

[0048] More specifically, a rubber blanket generally includes at least a rubber layer, a support layer, and a reinforcement layer. The rubber layer is usually made of synthetic rubber (such as styrene-butadiene rubber, chloroprene rubber) or natural rubber. The rubber layer is the surface layer of the rubber blanket and is in direct contact with the printing plate and paper. During the offset printing process, the main function of the rubber layer is to evenly transfer the ink from the printing plate to the paper. The elasticity and wear resistance of this layer determine the ink transfer efficiency of the rubber blanket. The support layer is usually made of fiber fabric, non-woven fabric, polyester fiber, or other composite materials. It is located between the rubber layer and the reinforcement layer and provides the necessary load-bearing capacity. Its main function is to withstand the mechanical pressure exerted on the rubber blanket during the offset printing process and maintain the shape of the rubber blanket to prevent deformation. The reinforcement layer is usually made of high-strength polymer or other reinforcing fiber materials such as polyester, nylon, or glass fiber. Its main function is to provide the rubber blanket with tensile strength and wear resistance, ensuring the long-term stable operation of the rubber blanket during the offset printing process.

[0049] Since the core part of the rubber blanket that plays the most important role in printing is the rubber layer structure, and the rubber layer is a soft material that is repeatedly crushed by high temperature and high pressure during the long-term printing process, it will cause local deformation of the rubber layer during long-term use, forming uneven areas such as concave areas on its printing surface, thereby affecting its normal printing process. In the prior art, when the printing surface of the rubber blanket is uneven, the rubber blanket is usually replaced to achieve the expected printing effect. For companies that do a lot of offset printing, replacing rubber blankets in large quantities will undoubtedly increase costs. Moreover, since some rubber blankets are only slightly damaged when they are replaced, their rubber layers are in a reversible state. Therefore, when all rubber blankets are replaced in large quantities, it will undoubtedly increase the cost of the company. Based on this, a method for repairing rubber blankets is proposed, in order to repair partially reversible rubber blankets to reduce costs, and therefore this application is proposed.

[0050] Example 1

[0051] See also Figure 1 The first embodiment provides a method for repairing a rubber blanket, which is used to restore the elasticity of a rubber blanket having a rebound elasticity greater than 85%, and specifically includes the following steps:

[0052] S10: Providing a rubber blanket damaged by offset printing, wherein the rubber blanket comprises at least a rubber layer, a support layer, and a reinforcement layer that are sequentially bonded together.

[0053] S20: Detecting and selecting rubber blankets with a rubber layer resilience greater than 85%.

[0054] It should be noted that the rubber blanket is subjected to a lot of pressure, friction and aging during the offset printing process, so it will gradually lose its original elasticity during use, and resilience refers to the ability of the material to return to its original shape after being compressed. When the resilience of the rubber blanket is greater than 85%, it means that the molecular chains in the rubber layer still have a strong cross-linking structure and can quickly return to their original shape after being acted upon by external force. If the resilience is lower than 85%, it means that its elastic recovery ability has been greatly reduced, and there may be problems such as aging and hardening, and it cannot be fully restored to the ideal state through subsequent repair operations. And when the resilience is lower than 85%, the cost of restoring the elasticity is high, and its recovery effect is poor. Therefore, this application selects 85% as the critical point based on enterprise cost considerations to screen out rubber blankets that are easy to recover and have good recovery effects.

[0055] Furthermore, in one specific embodiment, the method for testing the resilience of a blanket is as follows: First, a blanket sample of standard dimensions (e.g., 10 cm x 10 cm) is taken. The sample is then placed in a compressor, compressed at a specified pressure, and the pressure is released to measure the time it takes to return to its original thickness. Finally, the blanket's resilience is calculated using the formula: "Resilience = Recovery Thickness / Maximum Compressed Thickness," with a resilience of 85% being the cutoff point for screening.

[0056] Furthermore, after step S20, the following steps are further included:

[0057] S21: scrubbing the rubber layer with a brush to remove paper fibers on the rubber layer;

[0058] S22 sprays a cleaning liquid at 30° C. to 40° C. on the rubber layer to soften and clean the ink on the rubber layer.

[0059] It's important to note that during the offset printing process, paper fibers, ink residue, and other impurities often cling to the rubber blanket's surface. Brushing removes these tiny impurities through physical friction, preventing them from affecting the quality and surface smoothness of the rubber layer during subsequent repair operations. Failure to remove paper fibers from the rubber layer's surface can lead to uneven stress distribution during subsequent heating and stretching, resulting in poor localized rubber layer recovery or new surface damage. Therefore, brushing helps improve the uniformity and quality of the repair.

[0060] Furthermore, during the offset printing process, ink residue often forms on the rubber blanket surface. Ink is often complex, containing oily and resinous components. These components can solidify over time and adhere to the rubber surface, making them difficult to remove. Using a cleaning solution at 30°C-40°C effectively softens the ink, reducing its adhesion to the rubber layer and making the removal process more efficient.

[0061] In one embodiment, the cleaning solution is a mixture of hot water or warm water and an organic solvent (such as an alcohol solvent, a ketone solvent, or a lipid solvent).

[0062] S30: heating the rubber layer on the screened blanket to 50° C.-70° C. for the first time, and controlling the heating time to be 5-10 minutes.

[0063] It's important to note that rubber materials (such as the rubber layer in a blanket) possess unique thermophysical properties. Rubber is an elastic material, and its molecular chains are in a certain "glassy" or "rubbery" state at room temperature, meaning they can deform to a certain extent under external forces. However, over time and due to stress during use, the rubber chains can crosslink and harden, reducing their elasticity, making them more fragile and uneven.

[0064] Furthermore, when rubber is heated, its molecular chains begin to move, uncrosslinking the previously rigid, rigid chains and regaining fluidity, resulting in a softening effect. Heating the rubber returns to its original elastic state, restoring its flexibility and resilience. However, if the temperature is too high or the heating time is too long, the rubber layer may become excessively fluid, lose its shape, or even decompose.

[0065] Therefore, based on the above description, the applicant conducted experiments with heating temperatures ranging from 30°C to 130°C, with temperature nodes increasing by 10°C, and heating times of 1 minute, 5 minutes, and 10 minutes as experimental data points, and obtained the following experimental data:

[0066]

[0067]

[0068]

[0069] The above data indicates that within the temperature range of 50°C-70°C and a heating time of 5-10 minutes, the rubber blanket's resilience recovers to over 90%, which is within the acceptable elasticity range for offset printing. Therefore, this application sets the initial heating temperature at 50°C-70°C and the heating time at 5-10 minutes to soften and restore the rubber layer's resilience.

[0070] Furthermore, in a specific embodiment, step S30 specifically includes the following steps:

[0071] S31: providing a heating device;

[0072] S32: facing or pressing the heating device on the rubber layer of the blanket;

[0073] S33: Adjusting the temperature of the heating device to 50° C.-70° C. and adjusting the on-time of the heating device to 5-10 minutes to heat only the softened rubber layer.

[0074] It should be noted that due to the material properties of the rubber layer, the support layer and the reinforcement layer, the molecular structure within the support layer and the reinforcement layer is relatively stable. This application sets the heating device directly opposite the rubber layer to heat only the rubber layer, thereby avoiding heat waste and saving resources caused by increased heat.

[0075] In a specific embodiment, the heating device is a heating roller or a hot air blower.

[0076] S40: Cooling the blanket after the first heating to 20° C.-30° C. for a first time for 5-8 minutes, and stretching the rubber layer of the blanket after the first cooling at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5%.

[0077] It should be noted that cooling can help release the internal stress generated by the increased molecular chain movement during heating. After cooling to 20°C-30°C, the rubber molecular chains gradually stop excessive movement and stabilize their morphology, allowing the molecular chains to return to a relatively balanced thermal state. This prevents excessive softening without affecting elasticity and enhances the stretching effect.

[0078] Specifically, step S40 includes the following steps:

[0079] S41: Let the blanket after the first heating stand for 2-5 minutes;

[0080] S42: Cooling the blanket after standing still within 3 minutes to obtain a first state of the blanket after cooling;

[0081] S43: stretching the rubber layer of the blanket in the first state at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5%.

[0082] It should be noted that after the initial heating, the molecular chains in the rubber layer become active due to the increased temperature, potentially accumulating stress in different areas. By allowing the rubber layer to rest at high temperatures, the internal stress is gradually released, preventing stress concentration from causing cracks or deformation during subsequent operations. Temperature differences may occur in different areas of the rubber layer during the heating process. A rest period (2-5 minutes) helps to even out the temperature through thermal diffusion, making the molecular chains move more uniformly, thus providing a stable foundation for subsequent cooling operations. Specifically, according to Fourier's law of heat conduction: (where T is temperature; t is time; and α is the diffusion coefficient.) It can be seen that the longer the resting time t, the more uniform the temperature distribution T. Thus, after the initial heating of the blanket, the heat components within the blanket can be evenly distributed throughout the rubber layer during the 2-5 minute resting period. Preferably, the specific resting time depends on the composition of the rubber layer within the blanket.

[0083] Furthermore, by allowing the rubber blanket to rest for 2-5 minutes and then rapidly cooling it within 3 minutes, the rubber layer, after the initial heating, can be quickly fixed in its initial elastic state, while avoiding excessive relaxation or deformation of the molecular chains caused by slow cooling. Furthermore, the elastic modulus of the rubber is now stable, and the molecular chain morphology is more regular, allowing for more even stress distribution during subsequent stretching.

[0084] Furthermore, there are three stretching stages in the rubber material during the stretching process, as follows:

[0085] Elastic deformation stage: The molecular chain is stretched under the action of external force, but it is still in a reversible state. The strain is usually below 10%-15%;

[0086] Plastic deformation stage: external force causes irreversible deformation of the molecular chain, and the strain usually exceeds 15%-20%;

[0087] Fracture stage: The external force exceeds the ultimate strength of the material, the molecular chain breaks, and the strain is generally greater than 50%-200% (depending on the type of material).

[0088] In this application, the stretching range of 2%-5% is far below the elastic limit of 10%-15%, and falls within the range of fully elastic deformation. This means that the molecular chain can fully recover after stretching without causing plastic deformation or permanent damage. The specific derivation is as follows:

[0089] The stress-strain relationship of rubber materials can be expressed in the nonlinear form of Hooke's law, that is:

[0090] σ = E*ε; (σ is stress; E is the elastic modulus of the rubber layer; ε is strain, i.e., stretching amplitude).

[0091] For most rubber materials, the elastic modulus E is usually between 1 and 5 MPa. When the strain ε is controlled between 2% and 5%, the corresponding stress σ can be obtained as 0.02-0.25 MPa according to the above formula. The corresponding stress is much lower than the yield point of rubber (usually above 0.5 MPa), thus ensuring that the molecular chain is in an elastic deformation state and does not enter the plastic region.

[0092] Furthermore, according to the strain rate formula of rubber (where v is the stretching speed; L0 is the length of the rubber layer; Assume that the length of the rubber layer is 100 mm, then the strain rate of the rubber layer can be obtained. The optimal elasticity range of rubber materials known to those skilled in the art is 0.01 / s-0.1 / s.

[0093] Furthermore, the applicant conducted experiments on a 100 mm rubber blanket within the first cooling temperature range by adjusting the stretching amplitude and strain rate, and obtained the following experimental data:

[0094]

[0095] In summary, when the rubber blanket is stretched for the first time using the aforementioned stretching speed and stretching amplitude, good elastic deformation can be achieved while avoiding stress concentration caused by too high a speed or efficiency reduction caused by too slow a speed.

[0096] In one specific embodiment, the clamping mechanism simultaneously clamps and stretches the rubber layer, support layer, and reinforcement layer. The stretching speed and amplitude are well within the stretching range of the support and reinforcement layers, and are not further detailed here. Specifically, during the initial heating process, only the rubber layer is heated. Due to the thermal expansion and contraction of the rubber layer, the rubber layer expands and bends the entire blanket. The clamping mechanism simultaneously clamps and stretches the rubber layer, support layer, and reinforcement layer into a straight line, facilitating subsequent operations.

[0097] In another embodiment, the rubber layer, the support layer, and the reinforcement layer are separated by tearing their edges. The support layer and the reinforcement layer are fixed by a fixing device, and the rubber layer is clamped by a clamping device and stretched at the aforementioned stretching amplitude and stretching speed to straighten the rubber layer.

[0098] In summary, after the blanket is cooled to 20-30°C for the first time, the time is controlled to be 5-8 minutes, and the rubber layer in the first cooled blanket is stretched at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5% for the first time, the molecular chain can be gradually stretched and restored to elasticity, and the risk of fracture caused by stress concentration can be avoided.

[0099] S50: The first stretched blanket is heated to 80-100°C for the second time, and the heating time is controlled to be 10-15 minutes, and the rubber layer, the support layer and the reinforcing layer in the second heated blanket are stretched at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% for the second time;

[0100] It should be noted that after the first heating, the first cooling and the first stretching, because the materials of the rubber layer, the support layer and the reinforcing layer are different, the deformation amounts are different, so after the first stretching, the deformation amounts of the rubber layer, the support layer and the reinforcing layer are different, which will cause the uneven problem of the surface of the elastic recovery blanket after the first stretching, thereby affecting the normal offset printing quality. Based on this, the first stretched blanket is heated for the second time in this step S50, and the heating time is limited and the stretching speed and the stretching amplitude of the second stretching are limited, so that the rubber layer, the support layer and the reinforcing layer are stretched at the same time to make the printing surface of the rubber layer a flat plane.

[0101] Step S50 specifically includes:

[0102] S51: The first stretched blanket is placed in the heating device and heated to 80-100°C within 10-15 minutes to simultaneously heat and soften the rubber layer, the support layer and the reinforcing layer;

[0103] S52: The opposite sides of the rubber layer and the reinforcing layer are clamped at the same time using the clamping device, and the rubber layer, the support layer and the reinforcing layer are stretched at the same time at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% to simultaneously straighten the rubber layer, the support layer and the reinforcing layer.

[0104] It should be noted that, first of all, from the deduction above, the glass transition temperature Tg of the rubber layer is usually lower than 0°C. At 80°C-100°C, the molecular chain activity is enhanced, but there will be no excessive flow, ensuring the recovery of elastic deformation properties. As for the support layer (such as polyester) and the reinforcement layer (such as fabric), their thermal deformation points are usually between 70°C and 120°C. This temperature range is sufficient to relax their molecular structure, which is conducive to subsequent stretching and morphological correction (the thermal deformation points of polyester and fabric are common knowledge, and the size will not be elaborated on). This application sets a temperature in the range of 80°C-100°C for the second heating, which will soften the rubber layer, support layer and reinforcement layer at the same time, without causing thermal aging or molecular chain breakage due to heating, thereby maintaining the integrity and performance of the material.

[0105] Furthermore, from the stress-strain formula of Hooke's law mentioned above, it can be seen that at 80°C-100°C, the elastic modulus E decreases, and the molecular chains have a higher degree of freedom of movement, ensuring uniform stress distribution during stretching. Moreover, the above temperature can soften the rubber layer, support layer, and reinforcement layer at the same time, so that they can be stretched into a plane at the same time, thereby avoiding the problem of uneven surface of the rubber layer due to the different deformation amounts of the rubber layer, support layer, and reinforcement layer after the first stretching. To verify the above viewpoint, the applicant conducted experiments on the temperature, stretching speed, and stretching amplitude of the second heating and obtained the following experimental data:

[0106]

[0107] The experimental data above indicates that a temperature range of 80°C to 100°C is ideal, fully softening the rubber, support, and reinforcement layers, releasing internal stress and creating favorable conditions for stretching. Furthermore, a speed of 8-10 mm / s and a 5%-10% amplitude ensure synchronized deformation of the multilayer structure, restoring flatness and enhancing overall elasticity while avoiding permanent deformation and delamination.

[0108] S60: Cooling the blanket after the second stretching to room temperature for the second time, and cutting the edge of the blanket after the second stretching.

[0109] It should be noted that in the aforementioned steps, after the blanket undergoes the first heating, first cooling, first stretching, second heating, and second stretching, the blanket regains its normal elasticity, and the rubber layer now forms a flat surface. The second cooling to room temperature stabilizes the flat shape formed by the two stretchings, preventing deformation or elasticity loss due to subsequent temperature fluctuations. Furthermore, the support layer and reinforcement layer are stabilized in their coordinated stretched state through the cooling process, forming a highly stable whole with the rubber layer.

[0110] Furthermore, due to the different elastic deformations between the rubber layer, the support layer, and the reinforcing layer during the above-mentioned operation, the blanket is susceptible to delamination or cracking at the outermost edges of the blanket due to the differences in elastic deformation. This step eliminates delamination and cracking at the edges of the blanket by trimming the edges after the second heating.

[0111] Specifically, step S60 includes the following steps:

[0112] S61: Filling the edge of the blanket after the second cooling with adhesive and performing hot pressing operation;

[0113] S62: Cutting the cracked portion of the edge of the rubber blanket after hot pressing.

[0114] It should be noted that in step S61 and step S62, adhesive is filled in the edge of the rubber blanket and hot-pressed to re-bond and hot-press the rubber layer, the support layer and the reinforcement layer to ensure the integrity of the rubber blanket.

[0115] Furthermore, after step S62, the following steps are further included:

[0116] S63: Testing the resilience of the cut rubber blanket to select qualified rubber blankets.

[0117] It should be noted that step S63 tests the resilience of the cut blanket to ensure the yield rate of the repaired blanket. The specific resilience testing method is the same as the resilience testing method described above and will not be repeated here.

[0118] In this embodiment, the rubber layer of the selected rubber blanket is heated to 50°C-70°C for a first time, and the heating time is controlled to 5-10 minutes to enhance the mobility of the molecular chains in the rubber layer, thereby softening and restoring the rubber elasticity. After the rubber blanket is cooled for a first time, it is stretched for a first time to determine the initial state of the entire rubber blanket after elastic recovery. In this initial state, the rubber layer, support layer, and reinforcement layer of the rubber blanket are heated and stretched for a second time to stretch the rubber layer into a flat surface. The edges of the rubber blanket after the second stretching are trimmed to obtain a final usable rubber blanket, thereby converting discarded rubber blankets into qualified rubber blankets that can be continued in use, thereby reducing the company's costs.

[0119] Example 2

[0120] The second embodiment provides a rubber blanket repair device, and during the rubber blanket repair process, the rubber blanket repair method described in the first embodiment is applied, specifically including:

[0121] A screening mechanism for screening out rubber blankets with a rebound resilience greater than 85%;

[0122] A fixing mechanism is configured to fix the screened rubber blanket;

[0123] A temperature control mechanism is configured to perform first heating, first cooling, second heating and second cooling on the fixed rubber blanket;

[0124] A stretching mechanism is configured to perform first stretching on the first cooled rubber blanket and second stretching on the second heated rubber blanket;

[0125] A cutting mechanism is configured to cut the edge of the second stretched rubber blanket.

[0126] In a specific embodiment, the software system for monitoring data is used for the resilience detection of the rubber blanket in the second embodiment (which is prior art and will not be described here). The screening mechanism is a mechanical device structure connected to the detection equipment to guide the good products through the screening mechanism to the fixing mechanism for operation. The fixing mechanism is a structure of the existing rack plus clamping block, which is used to fix the rubber blanket when the screening mechanism guides the rubber blanket. The temperature control mechanism is a heating or cooling structure arranged under the rack of the fixing mechanism, which can be a combination of heating rollers, air heaters and refrigerators (the specific structure is prior art and will not be described here). The stretching mechanism is a stretching structure arranged at both ends of the rack to clamp and stretch the rubber blanket. The cutting mechanism is a cutting tool suspended above the rack.

[0127] Further, in order to ensure the yield of the repaired rubber blanket, the repairing device of the rubber blanket further comprises a hot pressing mechanism configured to perform edge hot pressing on the cut rubber blanket. It should be noted that the hot pressing mechanism is arranged above the rack and is used to perform edge hot pressing on the cut rubber blanket.

[0128] It should be noted that the repairing device of the rubber blanket proposed in the second embodiment completely applies the repairing method of the rubber blanket in the first embodiment, so the technical effects of the second embodiment are completely consistent with those of the first embodiment, which will not be described here.

[0129] The above only describes the embodiments of the present application, and it should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present application, but these all belong to the protection scope of the present application.

Claims

1. A method for repairing a rubber blanket, for restoring the elasticity of a rubber blanket having a rebound elasticity greater than 85%, characterized in that: The steps include: Providing a rubber blanket damaged by offset printing, wherein the rubber blanket comprises at least a rubber layer, a support layer and a reinforcement layer that are sequentially bonded together; Detect and select rubber blankets with a rubber layer resilience greater than 85%; The rubber layer on the screened blanket is heated to 50-70°C for the first time, and the heating time is controlled to be 5-10 minutes; The blanket after the first heating is cooled to 20° C.-30° C. for a first time for 5-8 minutes, and the rubber layer in the blanket after the first cooling is stretched at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5% for a first time; The rubber blanket after the first stretching is heated for a second time to 80-100° C., and the heating time is controlled to be 10-15 minutes. The rubber layer, the support layer and the reinforcement layer in the second heated rubber blanket are stretched together for a second time at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10%. The rubber blanket after the second stretching is cooled to room temperature for the second time, and the edge of the rubber blanket after the second stretching is cut.

2. The method for repairing a blanket according to claim 1, wherein: The step of "detecting and screening out rubber blankets with a rubber layer resilience greater than 85%" further includes the following steps: Scrub the rubber layer with a brush to remove paper fibers from the rubber layer; Spray 30℃-40℃ cleaning liquid on the rubber layer to soften and clean the ink on the rubber layer.

3. The method for repairing a blanket according to claim 1, wherein: The step of "heating the rubber layer on the screened blanket to 50° C.-70° C. for the first time and controlling the heating time to be 5-10 minutes" specifically includes the following steps: providing a heating device; facing or pressing the heating device onto the rubber layer of the blanket; The temperature of the heating device is adjusted to 50° C.-70° C., and the opening time of the heating device is adjusted to 5-10 minutes to heat only the softened rubber layer.

4. The method for repairing a blanket according to claim 3, wherein: The heating device is a heating roller or a hot air blower.

5. The method for repairing a blanket according to claim 1, wherein: The step of "cooling the blanket after the first heating to 20° C.-30° C. for a first time for 5-8 minutes, and stretching the rubber layer of the blanket after the first cooling at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5% for a first time" includes the steps of: Let the blanket, after the first heating, stand for 2-5 minutes; Cooling the blanket after standing still within 3 minutes to obtain a first state of the blanket after cooling; The rubber layer of the blanket in the first state is stretched at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5%.

6. The method for repairing a blanket according to claim 1, wherein: The step of "heating the blanket after the first stretching for a second time to 80° C.-100° C. and controlling the heating time to be 10-15 minutes, and jointly stretching the rubber layer, the support layer and the reinforcing layer of the blanket after the second heating for a second time at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10%" includes the steps of: Within 10-15 minutes, place the first stretched blanket in a heating device and heat it to 80-100°C to heat and soften the rubber layer, support layer, and reinforcement layer simultaneously; A clamping device is used to simultaneously clamp the rubber layer and the opposite sides of the reinforcement layer, and simultaneously stretch the rubber layer, the support layer and the reinforcement layer at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10%, so as to straighten the rubber layer, the support layer and the reinforcement layer at the same time.

7. The method for repairing a blanket according to claim 1, wherein: The step of "cooling the rubber blanket after the second stretching to room temperature for a second time and cutting the edge of the rubber blanket after the second stretching" includes the steps of: Filling the edge of the blanket after the second cooling with adhesive and performing hot pressing operation; Cut the cracked part of the edge of the rubber blanket after hot pressing.

8. The method for repairing a blanket according to claim 7, wherein: The step of "cutting the cracked portion of the edge of the rubber blanket after hot pressing" further includes the step of testing the resilience of the cut rubber blanket to screen out qualified rubber blankets.

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