Rubber blanket repairing method and device

Abstract

According to the rubber blanket repairing method and device, the rubber layer of the screened rubber blanket is heated to 50-70 DEG C for the first time, and the heating time is controlled to be 5-10 minutes, so that the activity of molecular chains in the rubber layer is enhanced, and the rubber elasticity is softened and restored. And cooling the rubber blanket for the first time and then stretching the rubber blanket for the first time so as to determine the initial state of the whole rubber blanket after the elasticity is recovered. The rubber layer, the supporting layer and the reinforcing layer in the rubber blanket are heated for the second time and stretched for the second time in the initial state, so that the rubber layer is stretched into a plane. And the edge part of the rubber blanket which is stretched for the second time is cut to obtain the final rubber blanket which can be used, so that the waste rubber blanket is converted into the qualified rubber blanket which can be continuously used, and the cost of an enterprise is reduced.

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] The rubber blanket is an essential and key consumable in the offset printing process. It is mainly used to transfer the image on the printing plate to the surface of the substrate. Its structure is usually composed of an outer rubber layer, an intermediate support layer and a reinforcement layer. It has good elasticity, pressure resistance and durability. During the printing process, the rubber blanket completes the ink transfer by applying uniform pressure to the image area. Its surface flatness directly determines the accuracy and quality of printing. Therefore, the rubber blanket needs to maintain stable physical properties and surface morphology during long-term use to meet the requirements of high-precision printing.

[0003] After long-term high-pressure use, the rubber blanket often has unevenness such as ripples and depressions due to aging, uneven force or wear of the rubber layer surface, which affects the printing quality. In order to solve this problem, the usual practice is to directly replace the uneven rubber blanket, or remove the uneven part of the rubber blanket by cutting, and then use the remaining part after cutting for processing or for specific printing needs.

[0004] During the printing process, the pressure on the rubber blanket varies, and the duration of the pressure is different. Therefore, among all the rubber blankets with uneven printing surfaces, some of them are irreversibly damaged because the pressure on their rubber surface exceeds the limit, but some of them are within the reversible range because the pressure is smaller. In the prior art, when the problem of unevenness of the rubber blanket occurs, the rubber blanket is always replaced or cut, which undoubtedly increases the consumables of the rubber blanket and increases the production cost of the enterprise. Summary of the invention

[0005] In view of this, it is necessary to provide a method and device for repairing a rubber blanket, which 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 rubber blanket, which is used to restore the elasticity of a rubber blanket having a rebound elasticity greater than 85%, and comprises 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 which are sequentially bonded and connected;

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

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

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

[0011] The rubber blanket after the first stretching is heated for the second time to 80°C-100°C, and the heating time is controlled to be 10-15 minutes, and the rubber layer, the support layer and the reinforcement layer in the rubber blanket after the second heating are stretched for the second time at a stretching speed of 8-10 mm / s and a stretching range 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 with 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 rubber 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 rubber 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, so as 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, and controlling the time to be 5-8 minutes, and stretching the rubber layer in the blanket after the first cooling for a first time at a stretching speed of 5-8 mm / s and a stretching amplitude of 2%-5%" includes the steps of:

[0022] Let the rubber blanket, which has been heated for the first time, stand for 2-5 minutes;

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

[0024] The rubber layer of the rubber 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 rubber blanket after the first stretching to 80°C-100°C for a second time, and controlling the heating time to be 10-15 minutes, and stretching the rubber layer, the support layer and the reinforcing layer in the rubber blanket after the second heating together for a second time at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10%" includes the steps of:

[0026] Within 10-15 minutes, the rubber blanket after the first stretching is placed in a heating device and heated to 80°C-100°C to heat and soften the rubber layer, the support layer and the reinforcement layer at the same time;

[0027] A clamping device is used to clamp the rubber layer and the opposite sides of the reinforcing layer at the same time, and the rubber layer, the supporting layer and the reinforcing layer are stretched at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% to straighten the rubber layer, the supporting layer and the reinforcing layer at the same time.

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

[0029] Fill the edge of the rubber blanket after the second cooling with adhesive and perform hot pressing operation;

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

[0031] In at least one embodiment of the present application, the step of “cutting the cracked portion of the edge of the rubber 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 repairing device, in the process of repairing the rubber blanket, uses the rubber blanket repairing method according to any one of claims 1 to 8, comprising:

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

[0035] A fixing mechanism, used for fixing the rubber cloth after screening;

[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, used for performing a first stretching on the rubber blanket after the first cooling, and for performing a second stretching on the rubber 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 comprises a heat pressing mechanism, and the heat pressing mechanism is used to perform heat pressing on the edges of the cut rubber blanket.

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

[0041] The present application heats the rubber layer of the screened rubber blanket to 50°C-70°C for the first time, and controls the heating time to 5-10 minutes to enhance the activity of the molecular chains in the rubber layer to soften and restore the rubber elasticity. After the first cooling, the rubber blanket is stretched for the first time to determine the initial state of the entire rubber blanket after the elasticity is restored. The rubber layer, the support layer and the reinforcement layer in the rubber blanket are heated and stretched for the second time in the initial state to stretch the rubber layer into a plane. The edge of the rubber blanket after the second stretching is cut to obtain the final rubber blanket that can be used, thereby converting the discarded rubber blanket into a qualified rubber blanket that can continue to be used, so as to reduce the cost of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flowchart of a rubber blanket repair method in Embodiment 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 may be directly connected to the other component or there may be a central component at the same time. When a component is considered to be "located on" another component, it may be directly located on the other component or there may be a central component at the same time. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "back", and similar expressions used herein are for illustrative purposes only.

[0045] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0046] In order to facilitate understanding of the technical solution of the present application, the rubber blanket involved in the present 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 the printing quality.

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

[0048] More specifically, the rubber blanket generally includes at least a rubber layer, a support layer and a reinforcement layer. The rubber layer is usually synthetic rubber (such as styrene-butadiene rubber, chloroprene rubber) or natural rubber, etc. The rubber layer is the surface layer of the rubber blanket, which is in direct contact with the printing plate and paper. In the offset printing process, the main function of the rubber layer is to transfer the ink on the printing plate to the paper evenly. 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, which is located between the rubber layer and the reinforcement layer to provide the necessary bearing capacity. Its main function is to withstand the mechanical pressure exerted on the rubber blanket during the offset printing process, and to keep the shape of the rubber blanket stable and avoid deformation. The reinforcement layer is usually a high-strength polymer or other reinforcing fiber material, such as polyester, nylon or glass fiber, etc. Its main function is to provide the tensile strength and wear resistance of the rubber blanket, and ensure 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 printing function 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 and form uneven areas such as concave 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 cause the problem of increased costs, and because part of the rubber blanket is only slightly damaged when it is replaced, its rubber layer is in a reversible state. Therefore, when all the rubber blankets are replaced in large quantities, it will undoubtedly increase the cost of the company. Based on this, a method for repairing a rubber blanket is proposed, in order to repair part of the reversible rubber blanket to reduce costs, so this application is proposed.

[0050] Embodiment 1

[0051] See also Figure 1 The first embodiment of the present invention 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 comprises 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 which are sequentially bonded and connected.

[0053] S20: Detect and select 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-linked structure and can quickly return to their original state after external force. If the resilience is lower than 85%, it means that its elastic recovery ability is 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 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 a specific embodiment, the method for testing the resilience of the rubber blanket is as follows: first, take a rubber blanket sample, the size of which should meet the standard (e.g., 10 cm x 10 cm). Then, place the sample in a compressor, compress it under a specified pressure, and release the pressure to measure the time it takes to recover to the original thickness. Finally, the resilience of the rubber blanket is calculated by the formula: "Resilience = Recovery Thickness / Maximum Compressed Thickness", and 85% resilience is used as the screening cutoff point.

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

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

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

[0059] It should be noted that during the offset printing process, some paper fibers, ink residues and other impurities often adhere to the surface of the rubber blanket. The role of brushing is to remove these tiny impurities through physical friction to prevent them from affecting the quality and surface flatness of the rubber layer in subsequent repair operations. If the paper fibers on the surface of the rubber layer are not removed, uneven stress distribution may occur during the subsequent heating and stretching process, resulting in poor recovery of the rubber layer in local areas or new surface damage. Therefore, the brushing process helps to improve the uniformity and quality of the repair.

[0060] Furthermore, during the offset printing process, ink often remains on the surface of the rubber blanket. The composition of the ink is usually complex, containing oily substances and resin components, which may solidify over time and adhere to the surface of the rubber layer, making it difficult to remove. Using a cleaning solution at 30℃-40℃ can effectively soften the ink and reduce the adhesion between the ink and the rubber layer, making the removal process more efficient.

[0061] In a specific 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 rubber blanket to 50° C.-70° C. for the first time, and controlling the heating time to be 5-10 minutes.

[0063] It should be noted that rubber materials (such as the rubber layer in the rubber blanket) have unique thermophysical properties. Rubber is an elastic material, and its molecular chains are in a certain "glass state" or "rubber state" at room temperature, that is, the molecular chains can undergo certain deformation under the action of external forces. However, as time goes by and the pressure during use, the rubber molecular chains will undergo cross-linking and hardening, resulting in reduced elasticity, becoming more fragile and uneven.

[0064] Furthermore, when the rubber is heated, the molecular chains begin to move, and the originally cross-linked and rigid molecular chains begin to de-crosslink and restore fluidity, which appears to soften. By heating, the rubber will return to its original elastic state, restoring elasticity and flexibility. If the heating temperature is too high or the heating time is too long, the rubber layer may flow excessively, lose its shape, or even cause decomposition.

[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 time nodes as experimental data points, and obtained the following experimental data:

[0066]

[0067]

[0068]

[0069] From the above data, it can be seen that within the temperature range of "50℃-70℃" and the heating time range of 5-10 minutes, the elasticity of the rubber blanket can be restored to more than 90%, which is an acceptable elasticity range for offset printing. Therefore, the present application sets the first heating temperature to 50℃-70℃ and the heating time to 5-10 minutes to soften and restore the elasticity of the rubber layer.

[0070] Further, in a specific embodiment, step S30 specifically includes the steps of:

[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 opening time of the heating device to 5-10 minutes, so as 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. The present application sets the heating device directly opposite to the rubber layer to heat only the rubber layer, thereby avoiding heat waste and saving resource waste caused by increasing 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 in the blanket after the first cooling at a stretching speed of 5-8 mm / s and a stretching range of 2%-5%.

[0077] It should be noted that cooling can help release the internal stress of rubber caused by increased molecular chain movement during heating. After cooling to 20℃-30℃, the rubber molecular chain gradually stops excessive movement and the shape tends to be stable, allowing the molecular chain to return to a relatively balanced thermal motion state, avoiding excessive softening without affecting elasticity and enhancing the stretching effect.

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

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

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

[0081] S43: stretching the rubber layer of the rubber 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 first heating, the molecular chains of the rubber layer become active due to the increase in temperature, and stress may accumulate in different areas. By standing still, the rubber layer can gradually release its internal stress at high temperature to avoid stress concentration in subsequent operations that may cause cracks or deformation. During the heating process, temperature differences may occur in different areas of the rubber layer. The standing time (2-5 minutes) helps to homogenize the temperature through heat diffusion, making the motion state of the molecular chains consistent, providing a stable basis for subsequent cooling operations. Specifically, according to Fourier's law of heat conduction: (where T is temperature; t is time; α is diffusion coefficient) It can be seen that the longer the standing time t is, the more uniform the temperature distribution T will be. Therefore, when the blanket is allowed to stand for 2-5 minutes after the first heating, the heat components in the blanket can be evenly distributed in various parts of the rubber layer. Preferably, the specific standing time depends on the mixed components of the rubber layer in the blanket.

[0083] Furthermore, by cooling the rubber blanket quickly within 3 minutes after standing for 2-5 minutes, the rubber layer after the first heating can be quickly fixed in a state of initial elastic recovery, while avoiding excessive relaxation or deformation of the molecular chain movement due to slow cooling. At this time, the elastic modulus of the rubber is stable, and the molecular chain morphology is more regular, so that the subsequent stretching can distribute the stress more evenly.

[0084] Furthermore, there are three stretching stages in the stretching process of rubber materials, 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 lower than the elastic limit of 10%-15%, which belongs to the range of complete elastic deformation. This means that the molecular chain can fully recover after stretching without 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, namely:

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

[0091] For most rubber materials, the elastic modulus E is usually 1-5MPa. When the strain ε is controlled at 2%-5%, the corresponding stress σ=0.02-0.25MPa can be obtained according to the above formula. The corresponding stress is much lower than the yield point of rubber (usually above 0.5MPa), so it can be ensured that the molecular chain is in an elastic deformation state and will 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; It is known that when the stretching speed v = 5-8mm / s, assuming that the length of the rubber layer is 100mm, the strain rate of the rubber layer can be obtained. The optimal elastic 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 to obtain the following experimental data:

[0094]

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

[0096] In a specific embodiment, the clamping mechanism simultaneously clamps and stretches the rubber layer, the support layer and the reinforcement layer, and the stretching speed and amplitude are completely within the stretching range of the support layer and the reinforcement layer, which will not be repeated here. Specifically, since only the rubber layer is heated during the first heating, and due to the thermal expansion and contraction of the rubber layer, the rubber layer will expand and make the entire rubber sheet in a curved state. When the clamping mechanism clamps and stretches together, the rubber layer, the support layer and the reinforcement layer can all be stretched to form a straight material for subsequent operations.

[0097] In another specific embodiment, the rubber layer, the support layer and the reinforcement layer are separated by tearing the edge portions of the rubber layer, the support layer and the reinforcement layer. 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 above-mentioned stretching amplitude and stretching speed to straighten the rubber layer.

[0098] In summary, after the rubber blanket is cooled to 20℃-30℃ for the first time and the time is controlled to be 5-8 minutes, and the rubber layer in the rubber blanket after the first cooling is stretched for the first time at a stretching speed of 5-8mm / s and a stretching amplitude of 2%-5%, it can ensure that the molecular chains gradually stretch and restore elasticity while avoiding the risk of breakage caused by stress concentration.

[0099] S50: heating the rubber blanket after the first stretching to 80° C.-100° C. for a second time, and controlling the heating time to be 10-15 minutes, and stretching the rubber layer, the support layer and the reinforcement layer in the rubber blanket after the second heating together at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% for a second time;

[0100] It should be noted that after the first heating, the first cooling and the first stretching, the rubber layer, the support layer and the reinforcement layer are made of different materials and have different deformations. Therefore, after the first stretching, the rubber layer, the support layer and the reinforcement layer have different deformations, which will cause the elastic recovery rubber layer surface to be uneven after the first stretching, thereby affecting the normal offset printing quality. Based on this, this step S50 heats the rubber blanket after the first stretching for the second time, and limits the above heating time and the stretching speed and stretching amplitude of the second stretching, so that the rubber layer, the support layer and the reinforcement layer are stretched at the same time so that the printing surface of the rubber layer is a flat plane.

[0101] Step S50 specifically includes:

[0102] S51: within 10-15 minutes, placing the rubber blanket after the first stretching in a heating device and heating it to 80° C.-100° C., so as to heat and soften the rubber layer, the support layer and the reinforcement layer at the same time;

[0103] S52: Using a clamping device to clamp the rubber layer and the opposite sides of the reinforcing layer at the same time, and simultaneously stretching the rubber layer, the supporting layer and the reinforcing 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 supporting layer and the reinforcing layer at the same time.

[0104] It should be noted that, first of all, from the derivation 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 performance. For the support layer (such as polyester) and the reinforcement layer (such as fabric), their thermal deformation points are usually 70°C-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). This application sets the 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, and will not cause 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 above, it can be seen that at 80℃-100℃, the elastic modulus E decreases, and the molecular chain has a higher degree of freedom of movement, ensuring uniform stress distribution during stretching. And the above temperature can soften the rubber layer, the support layer and the reinforcement layer at the same time, so that they can be stretched into a plane at the same time, so as to avoid the problem of uneven surface of the rubber layer due to different deformation amounts of the rubber layer, the support layer and the reinforcement layer after the first stretching. In order 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 above experimental data show that the ideal temperature range is 80℃-100℃, which can fully soften the rubber layer, support layer and reinforcement layer, release internal stress, and create good conditions for stretching operations. The speed of 8-10mm / s and the amplitude of 5%-10% ensure the synchronization of the deformation of the multi-layer structure, restore flatness and enhance overall elasticity, while avoiding permanent deformation and delamination problems.

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

[0109] It should be noted that in the above steps, after the rubber blanket is heated for the first time, cooled for the first time, stretched for the first time, heated for the second time, and stretched for the second time, the rubber blanket can recover its elasticity during normal use, and the rubber layer is now a flat surface. The second cooling to room temperature fixes the flat shape of the rubber blanket after two stretchings, thereby avoiding deformation or elastic loss due to subsequent temperature fluctuations. At this time, the support layer and the reinforcement layer are fixed in their coordinated stretched state through the cooling process, and together with the rubber layer, they form a highly stable whole.

[0110] Furthermore, in the above operation, since the elastic deformations of the rubber layer, the support layer and the reinforcing layer are different, the rubber blanket is prone to delamination or cracking at the outer edge due to the difference in elastic deformation in the overall layered structure of the rubber blanket. In this step, the delamination and cracking of the edge of the rubber blanket are eliminated by cutting the edge after the second heating.

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

[0112] S61: filling the edge of the rubber 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 heat 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 also 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, which will not be repeated here.

[0118] In the first embodiment of the present invention, the rubber layer of the screened rubber blanket is heated to 50°C-70°C for the first time, and the heating time is controlled to be 5-10 minutes to enhance the activity of the molecular chains in the rubber layer to soften and restore the rubber elasticity. After the first cooling, the rubber blanket is stretched for the first time to determine the initial state of the entire rubber blanket after the elasticity is restored. In the initial state, the rubber layer, the support layer and the reinforcement layer in the rubber blanket are heated and stretched for the second time to stretch the rubber layer into a plane. The edge part of the rubber blanket after the second stretching is cut to obtain the final rubber blanket that can be used, thereby converting the discarded rubber blanket into a qualified rubber blanket that can continue to be used, so as to reduce the cost of the enterprise.

[0119] Embodiment 2

[0120] The second embodiment provides a rubber blanket repairing device, and in the process of repairing the rubber blanket, the rubber blanket repairing method as described in the first embodiment is applied, which specifically includes:

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

[0122] A fixing mechanism, used for fixing the rubber cloth after screening;

[0123] A temperature control mechanism for performing a first heating, a first cooling, a second heating, and a second cooling on the fixed rubber blanket;

[0124] A stretching mechanism, used for performing a first stretching on the rubber blanket after the first cooling, and for performing a second stretching on the rubber blanket after the second heating;

[0125] The cutting mechanism is used for cutting the edge of the rubber blanket after the second stretching.

[0126] In a specific embodiment, a software system for monitoring data is used when the rubber blanket is tested for resilience in the second embodiment (this is a prior art and will not be described in detail here), and the screening mechanism is a mechanical equipment structure connected to the testing equipment to import good products into the fixing mechanism through the screening mechanism for operation. The fixing mechanism is a structure of an existing frame plus a clamping block, which is used to fix the rubber blanket when the screening mechanism imports the rubber blanket. The temperature control mechanism is a heating or cooling structure arranged under the frame of the fixing mechanism, which can be specifically a combination of a heating roller, a hot air blower and a refrigerator (this specific structure is an existing structure and will not be described in detail here). The stretching mechanism is a stretching structure arranged at both ends of the frame, which is used to clamp and stretch the rubber blanket. The cutting mechanism is a cutting tool suspended above the frame.

[0127] Furthermore, in order to ensure the yield rate of the repaired blanket, the blanket repair device further comprises a heat pressing mechanism, which is used to heat press the edges of the cut blanket. It should be noted that the heat pressing mechanism is arranged above the frame and is used to heat press the edges of the cut blanket.

[0128] It should be noted that the rubber blanket repairing device proposed in the second embodiment completely applies the rubber blanket repairing method in the first embodiment. Therefore, the technical effect produced by the second embodiment is completely consistent with that of the first embodiment and will not be repeated here.

[0129] The above is only an implementation method of the present application. It should be pointed out that a person skilled in the art can make improvements without departing from the inventive concept of the present application, but these improvements are within the scope of protection 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 at least comprises a rubber layer, a support layer and a reinforcement layer which are sequentially bonded and connected; Detect and select rubber blankets with rubber layer resilience greater than 85%; The rubber layer on the screened rubber blanket is heated to 50°C-70°C for the first time, and the heating time is controlled to be 5-10 minutes; The rubber blanket after the first heating is cooled to 20°C-30°C for a first time, and the time is controlled to be 5-8 minutes, and the rubber layer in the rubber blanket after the first cooling is stretched for the first time at a stretching speed of 5-8 mm / s and a stretching range of 2%-5%; The rubber blanket after the first stretching is heated for the second time to 80°C-100°C, and the heating time is controlled to be 10-15 minutes, and the rubber layer, the support layer and the reinforcement layer in the rubber blanket after the second heating are stretched for the second time at a stretching speed of 8-10 mm / s and a stretching range 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 rubber blanket according to claim 1, characterized in that: The step of "detecting and selecting rubber blankets with a rubber layer resilience greater than 85%" also includes the following steps: Brush 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 rubber blanket according to claim 1, characterized in that: The step of "heating the rubber layer on the screened rubber 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 rubber 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, so as to heat only the softened rubber layer.

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

5. The method for repairing a rubber blanket according to claim 1, characterized in that: The step of "cooling the rubber blanket after the first heating to 20° C.-30° C. for a first time and controlling the time to be 5-8 minutes, and stretching the rubber layer in the rubber 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 rubber blanket, which has been heated for the first time, stand for 2-5 minutes; Cooling the rubber blanket after standing still within 3 minutes to obtain a first state of the rubber blanket after cooling; The rubber layer of the rubber 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 rubber blanket according to claim 1, characterized in that: The step of "heating the rubber blanket after the first stretching to 80°C-100°C for the second time, controlling the heating time to 10-15 minutes, and stretching the rubber layer, the support layer and the reinforcing layer in the rubber blanket after the second heating together at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% for the second time" includes the steps of: Within 10-15 minutes, the rubber blanket after the first stretching is placed in a heating device and heated to 80°C-100°C to heat and soften the rubber layer, the support layer and the reinforcement layer at the same time; A clamping device is used to clamp the rubber layer and the opposite sides of the reinforcing layer at the same time, and the rubber layer, the supporting layer and the reinforcing layer are stretched at a stretching speed of 8-10 mm / s and a stretching amplitude of 5%-10% to straighten the rubber layer, the supporting layer and the reinforcing layer at the same time.

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

8. The method for repairing a rubber blanket according to claim 7, characterized in that: The step of "cutting the cracked portion of the edge of the rubber blanket after heat pressing" also includes the following steps: The resilience of the cut rubber blanket is tested to select qualified rubber blankets.

9. A rubber blanket repairing device, wherein during the rubber blanket repairing process, the rubber blanket repairing method according to any one of claims 1 to 8 is applied, characterized in that: include: A screening mechanism for screening out rubber cloths with a resilience greater than 85%; A fixing mechanism, used for fixing the rubber cloth after screening; A temperature control mechanism for performing a first heating, a first cooling, a second heating, and a second cooling on the fixed rubber blanket; A stretching mechanism, used for performing a first stretching on the rubber blanket after the first cooling, and for performing a second stretching on the rubber blanket after the second heating; The cutting mechanism is used for cutting the edge of the rubber blanket after the second stretching.

10. The rubber blanket repairing device according to claim 9, characterized in that: The rubber blanket repairing device further comprises a heat pressing mechanism, and the heat pressing mechanism is used for heat pressing the edge of the cut rubber blanket.

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