Safe explosion-proof tire and preparation process thereof

Abstract

According to the safe anti-explosion tire and the preparation technology thereof, a self-sealing elastic filling layer with the shear thickening characteristic is arranged in an inner cavity of a tire body, rapid response can be achieved when the safe anti-explosion tire is punctured, foreign matter is wrapped and a damage channel is sealed through viscoelastic flowing of materials, and therefore the gas escape process is remarkably slowed down; meanwhile, an annular limiting framework formed by splicing a plurality of arc-shaped metal segments is introduced to the outside of the tire body, and a stress dispersion grid woven by aramid fibers is laid on the annular limiting framework, so that a rigid-flexible combined anti-penetration system is formed, and local deformation expansion is inhibited; in addition, a multi-layer belt structure composed of a buffer transition layer, a main enhancement layer and an anti-fluid channeling isolation layer is arranged, and the overall anti-tearing capacity is further improved. The tire can still keep structural integrity and certain pressure bearing capacity after being punctured or cut, the potential safety hazard that a vehicle is out of control due to instant pressure loss of a traditional pneumatic tire is effectively solved, and the driving safety and the emergency disposal margin are improved.

Description

Technical Field

[0001] This invention relates to the field of tire technology, specifically to a safety explosion-proof tire and its manufacturing process. Background Technology

[0002] Currently, the traditional pneumatic tires widely used in vehicles rely primarily on compressed air to support loads and provide cushioning. These tires typically consist of an outer tread layer, carcass plies, belt layers, and an inner liner, and their operation depends on the integrity of the airtight cavity. However, in actual driving, tires are highly susceptible to punctures or cuts from sharp objects on the road surface. Once such damage occurs, a large amount of internal air will escape in a very short time, causing a sudden drop in tire pressure or even complete loss of pressure, i.e., a tire blowout. This sudden loss of pressure significantly alters the tire's mechanical properties, causing a sharp decline in vehicle handling stability, and in severe cases, can lead to serious traffic accidents such as loss of steering control, skidding, or rollovers.

[0003] Existing pneumatic tires lack an effective internal pressure maintenance mechanism. When the tire carcass is punctured, the elasticity of the rubber material alone is insufficient to prevent rapid gas leakage from the puncture. Although some products attempt to enhance structural strength by thickening the sidewalls or using rigid support rings, these designs often sacrifice tire smoothness and comfort, and still struggle to prevent continuous air leakage when faced with thin, long punctures. Therefore, effectively slowing down the rate of gas loss and maintaining drivability for a certain period after a tire is punctured or torn has become a pressing technical problem. Summary of the Invention

[0004] The present invention aims to provide a safe and explosion-proof tire and its manufacturing process, which effectively solves the safety hazard of vehicle loss of control caused by instantaneous pressure loss of traditional pneumatic tires, and improves driving safety and emergency response margin.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a safe and explosion-proof tire, wherein the tire comprises, from the inside out, a self-sealing elastic filler layer, an inner liner layer, a carcass ply layer, an annular limiting skeleton, a stress dispersion grid, a belt layer, and a wear-resistant tread. The self-sealing elastic filling layer is attached to the inner wall of the inner lining layer and is composed of hydrogenated nitrile rubber and liquid polybutadiene plasticizer with the addition of nano-silica. The annular limiting skeleton is composed of multiple arc-shaped metal segments spliced ​​into a ring structure, located between the carcass ply and the stress dispersion grid, and the interior of the annular limiting skeleton is filled with lightweight damping composite material. The stress dispersion grid is laid on top of the annular limiting skeleton and is woven from aramid filaments; The belt layer includes a buffer transition layer, a main reinforcement layer, and an anti-channeling isolation layer. The buffer transition layer is located above the stress dispersion grid. The main reinforcement layer is composed of ultra-high molecular weight polyethylene fiber strips arranged closely along the circumference of the tire. The anti-channeling isolation layer is located above the main reinforcement layer. The wear-resistant tread surface is provided with main grooves and inclined transverse grooves, and the central area of ​​the tread is treated with surface micro-texturing.

[0006] Preferably, the self-sealing elastic filler layer contains nano-silica particles, the surface of which is rich in silanol groups, forming a reversible cross-linked network with hydrogenated nitrile rubber segments through hydrogen bonding.

[0007] Preferably, each arc-shaped metal segment of the annular limiting skeleton has a U-shaped groove structure with a groove depth of 8 mm, a bottom arc radius of 2 mm, and two side wing plates that are tilted outward at 5 degrees. A 2 mm gap is left between adjacent skeleton segments, and the skeleton surface has multiple micropores and is coated with a silane coupling agent primer.

[0008] Preferably, an intermediate adhesive layer is provided between the anti-channeling isolation layer and the main reinforcing layer. The adhesive layer contains a styrene-butadiene copolymer component. The surface of the central grounding imprint area of ​​the wear-resistant tread is distributed with pits with a diameter of 100-200 micrometers and a density of 100-150 pits per square centimeter.

[0009] On the other hand, the present invention proposes a manufacturing process for a safe and explosion-proof tire, comprising the following steps: S1: A halogenated butyl rubber sheet is wrapped around a rotary forming drum to form an inner liner, and its outer surface is subjected to plasma bombardment treatment; then the tire carcass ply is wrapped around the outside of the inner liner, and pre-tension is applied and then the pressure roller is rolled; then the tire bead wires are embedded at both ends of the tire carcass and reinforcing core strips are added; finally, the assembled tire blank is subjected to initial vulcanization and shaping to obtain the basic tire carcass. S2: Prefabricated arc-shaped skeleton segments are processed on their surface and filled with damping composite material in the inner cavity of the skeleton; then the skeleton segments are placed one by one on the designated area of ​​the outer surface of the base tire, bonded with adhesive and connected with connectors to form a continuous ring structure; then an orthogonal mesh cloth woven from aramid filaments is laid on top of the skeleton as a stress dispersion mesh. S3: After applying adhesive to the surface of the stress dispersion grid, steel wire cord is bonded as a buffer transition layer; then adhesive is applied to the surface of the buffer transition layer, and ultra-high molecular weight polyethylene fiber tape is wrapped around to form the main reinforcement layer; then aramid bias fabric is laid on top of the main reinforcement layer as an anti-channeling isolation layer; finally, the belt layer is locally pressurized and cured. S4: Prepare the self-sealing compound, install the semi-finished tire carcass on the rotatable bracket; start the motor to make the tire carcass rotate at a constant speed, and at the same time inject the self-sealing compound into the tire cavity. Under the action of centrifugal force, it is evenly coated on the inner wall of the inner liner to form an annular liquid film of uniform thickness. S5: The coated tire carcass undergoes low-temperature cross-linking treatment to form a three-dimensional network structure; then the self-sealing layer is inspected and repaired; after confirmation of qualification, the assembled tire blank is placed in a vulcanization mold for step-by-step heating and vulcanization, and finally slowly cooled and demolded to obtain a fully formed safety explosion-proof tire.

[0010] Preferably, in S1, the plasma bombardment treatment has a power of 300-400 watts and a duration of 40-50 seconds, which increases the surface energy of the inner liner to 45-50 dynes / cm; the initial vulcanization temperature is 150-160 degrees Celsius, the internal pressure is maintained at 1.5-2.0 MPa, and the heating is continued for 25-35 minutes.

[0011] Preferably, in S2, the number of arc-shaped skeleton segments is 20-30, symmetrically distributed around the equatorial plane of the tire; the damping composite material filling the inner cavity of the skeleton is made of hollow glass microspheres and epoxy resin mixed in a weight ratio of 55-65:35-45; the placement position of the skeleton segments is limited to within ±25-35 mm from the equatorial line.

[0012] Preferably, in S3, the buffer transition layer is composed of two layers of steel wire fabric bonded together in a cross pattern of ±25-35°; the width of the ultra-high molecular weight polyethylene fiber tape of the main reinforcing layer is 45-55 mm, and the adjacent tapes are seamlessly connected; the temperature of local pressure curing is 105-115 degrees Celsius, the pressure is 0.35-0.45 MPa, and the walking speed is 1.5-2.5 meters per minute.

[0013] Preferably, in S4, the self-sealing compound is a mixture of hydrogenated nitrile rubber and liquid polybutadiene in a mass ratio of 5.5-6.5:3.5-4.5, and 10-15% of nano-silica is added; the tire body rotation speed is 25-35 revolutions per minute, the compound preheating temperature is 45-55 degrees Celsius, and the rotation coating time is 35-45 minutes.

[0014] Preferably, in S5, the low-temperature crosslinking treatment is carried out at a temperature of 55-65 degrees Celsius for a duration of 10-14 hours; the step-by-step heating vulcanization is first maintained at 165-175 degrees Celsius for 10-12 minutes, then increased to 190-200 degrees Celsius at a rate of 1.5-2.5 degrees Celsius per minute and held at that temperature for 16-20 minutes; the cooling stage is carried out at a rate of 1.0-2.0 degrees Celsius per minute to 75-85 degrees Celsius.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a self-sealing elastic filler layer with shear-thickening properties within the tire's inner cavity. This layer responds rapidly to punctures, using the viscoelastic flow of the material to encapsulate foreign objects and seal the damage channel, significantly slowing down gas escape. Simultaneously, an annular limiting skeleton composed of multiple arc-shaped metal segments is introduced onto the tire's exterior, with an aramid-woven stress-dispersing mesh laid on top, forming a rigid-flexible anti-penetration system that suppresses localized deformation. Furthermore, a multi-layered belt structure consisting of a buffer transition layer, a main reinforcement layer, and an anti-flow isolation layer further enhances overall tear resistance. This allows the tire to maintain structural integrity and a certain pressure-bearing capacity even after puncture or tearing, effectively solving the safety hazard of vehicle loss of control due to instantaneous pressure loss in traditional pneumatic tires, and improving driving safety and emergency response margin. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural diagram of the safety explosion-proof tire of the present invention; Figure 2 This is a schematic diagram of the structure of the annular limiting frame of the present invention; Figure 3 This is a schematic cross-sectional view of the belt layer structure of the present invention; Figure 4 This is a partial structural schematic diagram of the wear-resistant tread of the present invention.

[0017] In the diagram: 1. Self-sealing elastic filler layer; 2. Inner liner layer; 3. Carcass ply layer; 4. Annular limiting skeleton; 41. Arc-shaped metal sheet; 5. Stress dispersion grid; 6. Belt layer; 61. Buffer transition layer; 62. Main reinforcement layer; 63. Anti-channeling isolation layer; 7. Wear-resistant tread; 71. Main groove; 72. Lateral groove. Detailed Implementation

[0018] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0019] Example 1

[0020] This invention proposes a safe and explosion-proof tire, aiming to solve the problem of instantaneous pressure loss caused by the rapid loss of internal gas when traditional pneumatic tires suffer sudden damage such as punctures or cuts. This embodiment proposes a novel tire structure with a self-sealing buffer structure and a multi-layer tear-resistant skeleton support system, combined with a staged molding and curing process to achieve dynamic maintenance of internal tire pressure. This structure, by setting a continuous elastic filling layer in the tire cavity, utilizes material deformation and viscoelastic response to slow the gas escape rate when an external force punctures the tire; simultaneously, the introduction of a high-modulus fiber-reinforced belt layer and an annular limiting skeleton enhances the overall tensile and shear strength of the structure, thereby physically inhibiting the tendency for crack propagation.

[0021] In addition, by optimizing the spatial arrangement and interface characteristics between the functional layers, good compliance and grip performance are ensured under normal driving conditions, while the passive protection effect is quickly activated under abnormal stress conditions.

[0022] like Figures 1-4 As shown, the tire proposed in this embodiment includes, from the inside out, a self-sealing elastic filler layer 1, an inner liner layer 2, a carcass ply layer 3, an annular limiting skeleton 4, a stress dispersion grid 5, a belt layer 6, and a wear-resistant tread 7.

[0023] Furthermore, the self-sealing elastic filler layer 1 is attached to the inner wall of the inner liner layer 2 and is composed of hydrogenated nitrile rubber and liquid polybutadiene plasticizer with added nano-silica. Nano-silica particles are distributed inside the self-sealing elastic filler layer. The surface of the nano-silica particles is rich in silanol groups and forms a reversible cross-linked network with the hydrogenated nitrile rubber segments through hydrogen bonding.

[0024] Under normal driving conditions, the hydrogen bond network within the self-sealing elastic filler layer is in dynamic equilibrium, exhibiting a soft gel-like state with good fluidity and extensibility, without negatively impacting the tire's smoothness or rolling performance. When the tire is punctured by a sharp object, the localized area experiences high-speed shearing, intensifying the relative motion between nano-silica particles. This leads to the instantaneous disruption and rearrangement of numerous hydrogen bonds, absorbing energy and causing a rapid increase in material viscosity, exhibiting shear thickening behavior. As the viscosity rises sharply, the material transforms from a low-damping fluid to a near-solid state, forming a locally hardened zone around the puncture channel, effectively preventing gas from rapidly escaping along the damage path. Simultaneously, due to the reversible nature of hydrogen bonds, some hydrogen bonds can reassociate after the external force is removed or stress is released, giving the material a certain degree of self-healing capability and maintaining the continued effectiveness of the sealing function. This mechanism achieves passive-response sealing in response to puncture events, significantly extending the controllable driving time of the tire under depressurization conditions and improving the safety redundancy of vehicle operation.

[0025] Furthermore, the annular limiting skeleton 4 is composed of multiple arc-shaped metal pieces 41 segments spliced ​​into a ring structure, located between the carcass ply layer 3 and the stress dispersion grid 5. The interior of the annular limiting skeleton 4 is filled with a lightweight damping composite material. Each arc-shaped metal segment of the annular limiting skeleton has a U-shaped groove structure with a groove depth of 8 mm, a bottom arc radius of 2 mm, and two side wing plates that are tilted outward at 5 degrees. A 2 mm gap is left between adjacent skeleton segments. The skeleton surface has multiple micropores and is coated with a silane coupling agent primer.

[0026] This structure effectively constrains localized tire deformation and synergistically dissipates impact energy. The U-shaped groove design provides radial stiffness support, resisting excessive tire indentation upon the intrusion of sharp objects and preventing damage from extending into the inner layers. The lightweight damping composite material filled within the groove undergoes slight compressive deformation upon impact, absorbing some kinetic energy through the material's internal viscoelastic response and slowing down the penetration speed. The gaps between adjacent segments allow the overall structure to undergo moderate deformation during tire flexing, avoiding stress concentration in the connection area and improving durability. Surface micropores and a silane coupling agent primer enhance the interfacial bonding strength between the metal skeleton and the surrounding rubber matrix, ensuring effective load transfer and preventing debonding or slippage during use. The multiple arc-shaped segment splicing method balances installation convenience and structural continuity, ensuring uniform distribution of circumferential support while reducing overall mass, which helps maintain tire dynamic balance performance.

[0027] Furthermore, a stress-dispersing mesh 5, woven from aramid filaments, is laid above the annular limiting skeleton 4. This structure efficiently diffuses locally concentrated loads in both the circumferential and axial directions, reducing the peak stress per unit area. When the tire experiences a point impact or puncture, the high strength and high modulus of the aramid filaments enable a rapid response. Through the tension transmission of the fiber network, the external force, originally concentrated in a small area, is dispersed to a larger area, preventing excessive stress concentration that could lead to material tearing or delamination. Simultaneously, the woven structure provides excellent anisotropic mechanical adaptability, maintaining a stable force transmission path even under complex dynamic loads. Together with the annular limiting skeleton, it suppresses deformation propagation and enhances overall impact resistance.

[0028] Furthermore, the belt layer 6 includes a buffer transition layer 61, a main reinforcement layer 62, and an anti-crossing isolation layer 63. The buffer transition layer 61 is located above the stress dispersion grid 5. The main reinforcement layer 62 is composed of ultra-high molecular weight polyethylene fiber strips tightly arranged along the tire circumference. The anti-crossing isolation layer 63 is located above the main reinforcement layer 62. An intermediate adhesive layer is provided between the anti-crossing isolation layer and the main reinforcement layer. The adhesive layer contains styrene-butadiene copolymer. The surface of the central ground contact mark area of ​​the wear-resistant tread is distributed with pits with a diameter of 100-200 micrometers and a density of 100-150 pits per square centimeter.

[0029] This multi-layered belt structure achieves graded protection from stress reception and circumferential restraint to crack prevention. The buffer transition layer effectively mitigates high-frequency vibrations from the road surface and smoothly transfers the load diffused by the stress dispersion grid, reducing interfacial fatigue damage caused by abrupt changes in modulus. The main reinforcement layer, with its high circumferential orientation of ultra-high molecular weight polyethylene fibers, provides strong circumferential tensile strength, resists circumferential expansion forces under internal air pressure, prevents tire bulging or radial expansion instability, and maintains overall load-bearing capacity even when local fibers are damaged. The anti-channeling isolation layer, with its large-angle oblique fiber layout, forms a dense barrier, significantly increasing the path length and fracture energy required for crack propagation along the thickness direction, effectively inhibiting damage from the outside to the inside. The styrene-butadiene copolymer component in the intermediate adhesive layer enhances the wettability and bonding durability between the fibers and rubber, ensuring that each functional layer works synergistically under complex stress environments.

[0030] Furthermore, the wear-resistant tread 7 has a main groove 71 and inclined lateral grooves 72 on its surface, and the central area of ​​the tread is treated with surface micro-texturing. The micro-pit structure in the central area of ​​the tread increases the actual contact area between the rubber and the wet road surface, and under thin water film conditions, it punctures the water film to form a micro-anchoring effect, improving wet grip performance without sacrificing the strength of the tread body, thus balancing wear resistance and safety.

[0031] The manufacturing process of the above-mentioned safety explosion-proof tire includes the following steps: S1: A halogenated butyl rubber sheet is wrapped around a rotary forming drum to form an inner liner, and its outer surface is subjected to plasma bombardment treatment; then the tire carcass ply is wrapped around the outside of the inner liner, and pre-tension is applied and then the pressure roller is rolled; then the tire bead wires are embedded at both ends of the tire carcass and reinforcing core strips are added; finally, the assembled tire blank is subjected to initial vulcanization and shaping to obtain the basic tire carcass. Furthermore, the plasma bombardment treatment is carried out at a power of 300-400 watts for a duration of 40-50 seconds, which increases the surface energy of the inner liner to 45-50 dynes / cm; the initial vulcanization and setting temperature is 150-160 degrees Celsius, the internal pressure is maintained at 1.5-2.0 MPa, and the heating is continued for 25-35 minutes.

[0032] S2: Prefabricated arc-shaped skeleton segments are processed on their surface and filled with damping composite material in the inner cavity of the skeleton; then the skeleton segments are placed one by one on the designated area of ​​the outer surface of the base tire, bonded with adhesive and connected with connectors to form a continuous ring structure; then an orthogonal mesh cloth woven from aramid filaments is laid on top of the skeleton as a stress dispersion mesh. Furthermore, the number of arc-shaped skeleton segments is 20-30, symmetrically distributed around the equator of the tire; the damping composite material filling the inner cavity of the skeleton is made of hollow glass microspheres and epoxy resin mixed in a weight ratio of 55-65:35-45; the placement of the skeleton segments is limited to within ±25-35 mm from the equator.

[0033] S3: After applying adhesive to the surface of the stress dispersion grid, steel wire cord is bonded as a buffer transition layer; then adhesive is applied to the surface of the buffer transition layer, and ultra-high molecular weight polyethylene fiber tape is wrapped around to form the main reinforcement layer; then aramid bias fabric is laid on top of the main reinforcement layer as an anti-channeling isolation layer; finally, the belt layer is locally pressurized and cured. Furthermore, the buffer transition layer is composed of two layers of steel wire fabric bonded together in a ±25-35° cross pattern; the width of the ultra-high molecular weight polyethylene fiber tape of the main reinforcing layer is 45-55 mm, and the adjacent tapes are seamlessly connected; the temperature of local pressure curing is 105-115 degrees Celsius, the pressure is 0.35-0.45 MPa, and the walking speed is 1.5-2.5 meters per minute.

[0034] S4: Prepare the self-sealing compound, install the semi-finished tire carcass on the rotatable bracket; start the motor to make the tire carcass rotate at a constant speed, and at the same time inject the self-sealing compound into the tire cavity. Under the action of centrifugal force, it is evenly coated on the inner wall of the inner liner to form an annular liquid film of uniform thickness. Furthermore, the self-sealing compound is made by mixing hydrogenated nitrile rubber and liquid polybutadiene at a mass ratio of 5.5-6.5:3.5-4.5, and adding 10-15% nano-silica in total; the tire body rotation speed is 25-35 revolutions per minute, the preheating temperature of the compound is 45-55 degrees Celsius, and the spin coating time is 35-45 minutes.

[0035] S5: The coated tire carcass undergoes low-temperature cross-linking treatment to form a three-dimensional network structure; then the self-sealing layer is inspected and repaired; after confirmation of qualification, the assembled tire blank is placed in a vulcanization mold for step-by-step heating and vulcanization, and finally slowly cooled and demolded to obtain a fully formed safety explosion-proof tire.

[0036] Furthermore, the low-temperature crosslinking treatment is carried out at a temperature of 55-65 degrees Celsius for 10-14 hours; the step-by-step heating vulcanization is first maintained at 165-175 degrees Celsius for 10-12 minutes, then increased to 190-200 degrees Celsius at a rate of 1.5-2.5 degrees Celsius per minute and held at that temperature for 16-20 minutes; during the cooling stage, the temperature is reduced to 75-85 degrees Celsius at a rate of 1.0-2.0 degrees Celsius per minute.

[0037] This fabrication process achieves the orderly integration of multiple materials and structural levels through staged molding and precise parameter control. Plasma bombardment treatment effectively activates the surface of the inner liner layer, significantly improving its interfacial bonding with the carcass ply layer, laying the foundation for the stability of the subsequent composite structure. The initial vulcanization is completed under moderate temperature and pressure conditions to shape the tire carcass, ensuring both the degree of rubber crosslinking and preventing premature curing that could affect subsequent processing adaptability. The prefabrication and precise installation of the arc-shaped skeleton segments ensure the spatial positioning accuracy of the annular limiting structure, while the filling of damping composite materials enhances the impact energy absorption capacity, and the symmetrical distribution and reasonable spacing design balance rigid support and tire flexural flexibility.

[0038] The stress dispersion grid is laid close to the top of the skeleton, forming a continuous load diffusion channel to ensure that external impact energy is transferred and dispersed in a timely manner. The functional layers of the belt layer are stacked sequentially and cured by local pressure to promote interlayer fusion, achieving stable anchoring of the reinforced structure without causing excessive reaction of the overall rubber. The continuous winding of the main reinforcing layer ensures the uniformity and integrity of the circumferential strength.

[0039] Centrifugal casting utilizes the principles of rotational dynamics to allow the self-sealing compound to spread naturally under inertial forces, resulting in a highly uniform inner coating and avoiding defects caused by manual operation. The low-temperature cross-linking process constructs a three-dimensional network of the self-sealing layer under mild conditions, preserving the mobility of the material chain segments while providing the necessary cohesive strength to prevent detachment or cracking during use.

[0040] The final stepped temperature-increase vulcanization process achieves gradient heat penetration from the outside in, ensuring full vulcanization of the outer tread rubber while preventing excessive reaction of the inner self-sealing material. This harmonizes the different reaction rates of the various materials and reduces internal stress accumulation. The slow cooling process further releases thermal shrinkage stress, ensuring dimensional stability and dynamic balance of the finished product. The overall process flow is logically rigorous, with reasonable parameter windows for each step, guaranteeing the manufacturability and product consistency of complex tire structures.

[0041] Example 2

[0042] This embodiment further proposes a manufacturing process for a safe and explosion-proof tire, including the following steps: Step 1: Constructing the basic tire carcass structure This step aims to create a basic tire carcass with initial load-bearing capacity and geometric contours, serving as a support platform for subsequent functional layer stacking. This basic tire carcass, from the inside out, comprises an inner liner, a carcass ply, and a tread base layer. These three layers are tightly bonded together through a thermo-curing process, forming an integral framework with stable curvature and axial stiffness. The inner liner is made of low-permeability synthetic rubber, its main function being to reduce natural permeation loss of compressed air and provide a uniform surface for the subsequent adhesion of self-sealing materials. The carcass ply incorporates high-strength polyester fiber cords in a diagonal arrangement, giving the tire carcass resistance to bursting under radial loads. The tread base layer, as the outermost load-bearing structure, is pre-coated with a weakly cross-linked adhesive to facilitate precise bonding of the wear-resistant tread in the next stage. The entire basic tire carcass undergoes initial vulcanization and shaping in a mold, ensuring no air bubbles or slippage between layers, laying the foundation for structural stability in subsequent processing.

[0043] (1.1) Lay the inner lining layer and perform surface activation treatment. First, a 1.8 mm thick halogenated butyl rubber sheet is uniformly coated circumferentially onto a rotary forming drum. This sheet, continuously extruded and cut to the required width, contains chlorine or bromine functional groups in its molecular chain, significantly reducing the diffusion coefficients of oxygen and nitrogen. To enhance the adhesion strength between the sheet and the carcass ply, plasma bombardment treatment is immediately applied to its outer surface after coating, with a power setting of 350 watts and a duration of 45 seconds. This process generates a large number of hydroxyl (-OH) and carboxyl (-COOH) polar groups on the rubber surface, increasing the surface energy to over 48 dynes / cm, thereby improving the subsequent wetting and spreading effect of the rubber compound. Without this treatment, the subsequent interlaminar shear strength will be difficult to meet design requirements, and delamination and debonding are likely to occur in stress concentration areas.

[0044] (1.2) Wrap the carcass ply and apply pretension. Outside the surface-activated inner liner, two layers of polyester cord fabric arranged at ±55° intersection angles are sequentially bonded using an automated bonding machine. Each layer has a cord density of 28 cords per inch and a cord diameter of 0.8 mm. During bonding, a constant tension of 160 Newtons is applied to the unwinding roller via a servo control system to ensure that the cords do not buckle or loosen during bonding. After the cord layers completely cover the inner liner, a pressure roller is used to roll the inner liner three times in a circumferential direction at a pressure of 0.3 MPa to remove trapped air and promote mechanical anchoring between the cords and the rubber matrix. Because the surface of the inner liner has been activated, the rubber compound can more easily penetrate into the cord gaps, forming a "finger-like interpenetrating" structure, thereby significantly improving the interfacial bonding strength. This structure allows the cords to effectively bear most of the circumferential tensile stress when the tire carcass expands under internal air pressure, preventing the inner liner from being overstretched and cracking.

[0045] (1.3) Install the bead wire and position the reinforcing core strip. Near the rim mounting positions at both ends of the tire carcass, bead rings made of twisted high-carbon steel wire are embedded, each with a diameter of 4.2 mm and a tensile strength of not less than 2200 MPa. The bead rings are covered with a brass-plated adhesive tape. This tape reacts chemically with the surrounding rubber during heat vulcanization to form a Cu-S bond bridging structure, ensuring that the bead does not rotate relative to the rim. Subsequently, a trapezoidal nylon reinforcing strip, 6 mm high and 10 mm wide at the base, is added to the outside of the bead rings. Its function is to resist compression deformation from the rim edge during tire installation and to transmit lateral forces when the vehicle is cornering. Since the tire carcass ply is already pre-tensioned, its ends are then wrapped around the bead wire and pressed firmly against the outside of the strip, making the wrapped section 25 mm long, further improving the overall stiffness and durability of the bead area.

[0046] (1.4) Perform initial vulcanization and set the shape, and test the geometric accuracy. The assembled tire blank is fed into a bladder-shaped vulcanizing machine. After the mold is closed, high-temperature saturated steam is injected, raising the temperature to 155 degrees Celsius and maintaining the internal pressure at 1.8 MPa for 30 minutes. Under these conditions, cross-linking reactions occur between the rubber molecular chains, transforming the linear structure into a three-dimensional network structure, completing the transformation from a plastic body to an elastomer. After vulcanization, the mold is opened and the tire body is removed. After cooling to room temperature, its outer contour is measured using a laser scanner, with particular attention to checking whether the diameter deviation at the equator is less than ±0.5 mm and whether the consistency error of the tire shoulder fillet radius is less than ±0.3 mm. If these limits are exceeded, the mold parameters must be adjusted or the forming drum speed must be recalibrated. Only when the geometric dimensions meet the standards can the next stage of processing begin; otherwise, misalignment risks will occur during the subsequent bonding of functional layers, affecting the sealing performance and dynamic balance characteristics of the final product.

[0047] Step 2: Integrating the ring-shaped limiting frame and stress dispersion structure A ring-shaped limiting skeleton system is added to the outer surface of the already formed base tire to constrain the nonlinear deformation behavior of the tire carcass under extreme operating conditions, especially when subjected to impact from sharp objects, thereby limiting the crack propagation path through rigid support. This skeleton is composed of multiple arc-shaped metal segments, symmetrically distributed around the tire's equator, located between the tire carcass ply and belt layers, forming a barrier against radial intrusion. Each segment is stamped from titanium alloy into a U-shaped channel structure with a wall thickness of 1.2 mm, opening towards the tread direction, and filled with lightweight polymer foam to reduce overall weight. A 2 mm gap is left between the skeleton segments to allow for moderate bending during tire rolling, avoiding stress concentration at the connection points. To achieve effective anchoring between the skeleton and the rubber matrix, dense micropores are pre-drilled on its surface, and a primer containing a silane coupling agent is sprayed on to improve interfacial bonding durability. Furthermore, a layer of radially arranged aramid fiber mesh is laid on top of the skeleton to diffuse concentrated loads circumferentially, reducing the peak pressure per unit area.

[0048] (2.1) Design and prefabricate the ring-shaped limiting skeleton segment. Based on the tire's outer contour data obtained in the first step, 3D modeling software was used to create arc-shaped skeleton units with matching curvature. Each segment corresponds to a central angle of 15 degrees, with a total of 24 segments encircling the tire. Ti-6Al-4V titanium alloy sheet was selected due to its high specific strength and good fatigue life. It was machined into a U-shaped cross-section using a CNC punch press, with a groove depth of 8 mm, a bottom arc radius of 2 mm, and side flanges tilted outwards at 5 degrees to facilitate demolding. M4 threaded holes were provided at both ends of each segment for later mechanical connection with adjacent parts. After machining, sandblasting was performed to remove the surface oxide layer and increase roughness. The measured Ra value reached 3.2 micrometers, creating favorable conditions for subsequent coating adhesion. Since the skeleton will be in an alternating stress environment for a long time, any manufacturing defects may become crack initiation points. Therefore, it is necessary to ensure that the edges are free of burrs and folds, and that dimensional tolerances are controlled within ±0.1 mm.

[0049] (2.2) Fill the inner cavity of the skeleton with lightweight damping composite material To reduce the vibration response of the frame itself and absorb some impact energy, a damping composite material made of hollow glass microspheres and epoxy resin is filled inside the U-shaped groove. The ratio, by weight, is 60% hollow microspheres and 40% epoxy resin. After thorough mixing, the mixture is injected into the frame cavity using a vacuum infusion method at a pressure of 0.1 MPa and a holding time of 5 minutes, ensuring the material fully fills all corners without generating air bubbles. The hollow microspheres have an average particle size of 50 micrometers, a wall thickness of 2 micrometers, and contain an inert gas with a density of only 0.6 g / cm³, significantly reducing the overall component's mass increment. The cured composite material has a Young's modulus of approximately 3.5 GPa, far lower than the metal body, allowing for minute compressive deformation upon impact, dissipating kinetic energy. More importantly, when a sharp object punctures the tire tread, this filling layer provides a certain reaction force, slowing the penetration speed and buying time for the self-sealing layer to react.

[0050] (2.3) Fix the skeleton fragment to the designated area of ​​the fetus. Using specialized clamps, 24 skeleton segments are individually placed on the outer surface of the tire body, with their positions limited to within ±30 mm of the equator to ensure symmetrical distribution. Each segment is bonded to the tire carcass ply using a two-component fast-curing adhesive, with the adhesive layer thickness controlled at 0.3 mm. Curing is performed at room temperature for 2 hours. Before bonding, the bonding surfaces are wiped with anhydrous ethanol to remove oil and dust. After the adhesive has initially cured, stainless steel rivets are passed through the threaded holes at the ends of adjacent segments and tightened to form a continuous ring structure. Since the tire carcass has already gained sufficient rigidity through vulcanization in the first step, there will be no significant deformation due to localized loading, thus ensuring the accuracy of the skeleton installation position. After all connections are completed, the overall structure has a certain degree of flexibility in the circumferential direction, allowing it to deform synchronously during tire flexing, while the radial stiffness is significantly improved, effectively preventing localized indentation depth from exceeding the critical value.

[0051] (2.4) Laying aramid fiber stress dispersion grid Above the annular limiting skeleton, a layer of orthogonal mesh fabric woven from aramid filaments is manually laid, with a warp and weft density of 12 threads per centimeter and a linear density of 1100 denier. During laying, uniform tension is maintained to avoid wrinkles or slack, and the edges extend 10 mm beyond the skeleton area to allow for overlap with subsequent belt layers. Aramid fibers possess extremely high elongation at break (approximately 3.5%) and excellent cut resistance, enabling them to rapidly convert point loads into surface loads upon impact, allowing stress to diffuse in both circumferential and axial directions. For example, when a 3 mm diameter steel nail is vertically driven into the tire tread, the pressure originally concentrated within a 5 mm diameter area can be expanded to an area with a diameter of over 20 mm, thereby reducing shear stress per unit area. This mesh fabric works synergistically with the skeleton; the former is responsible for energy dispersion, and the latter provides rigid support, together forming the first line of defense against external attacks.

[0052] Step 3: Constructing a multi-layered tear-resistant belt layer To further enhance the tire's resistance to high-speed cutting and deep punctures, a three-layered anti-tear belt layer is constructed on top of a stress-dispersing grid. From bottom to top, this system consists of a buffer transition layer, a main reinforcement layer, and an anti-crossing isolation layer. Each layer is made of high-strength fiber composite material with different orientations, and they are firmly bonded together by an intermediate adhesive layer. The buffer transition layer uses steel cords arranged at a small angle of ±30°, primarily to absorb high-frequency vibrations from the road surface and mitigate modulus differences between the upper and lower layers. The main reinforcement layer uses unidirectionally arranged ultra-high molecular weight polyethylene fiber strips, tightly fitted along the tire circumference to provide the strongest circumferential restraint. The anti-crossing isolation layer is a single-layer aramid bias-ply fabric with an angle of ±70°; its high shear modulus prevents cracks from penetrating from the tread into the tire carcass. The total thickness of the entire belt layer is controlled within 4.5 mm, ensuring sufficient protection without significantly increasing rolling resistance.

[0053] (3.1) Adhesive buffer transition layer to achieve gradual modulus transition A 0.2 mm thick layer of natural rubber modified adhesive is uniformly coated onto the surface of the aramid mesh completed in the second step. This adhesive contains 5% carbon black N330 and 3% vulcanization accelerator, exhibiting good initial tack and thermal flowability. Subsequently, two pre-cut layers of steel cord fabric are bonded to the adhesive layer at ±30° angles. The cord specifications are 20 strands per inch, 0.75 mm in diameter, and the tension is controlled at 140 Newtons. Because the aramid mesh itself has a certain degree of elasticity, while the steel cord has high stiffness, direct bonding can easily cause abrupt changes in interfacial stress. By introducing this buffer structure, the stiffness variation can exhibit a gradient distribution, similar to the concept of "functionally graded materials" in materials science. Specifically, the longitudinal elastic modulus change from the carcass to the belt layer follows an approximate law as follows: ; in, E0 represents the equivalent modulus at a height z above the inner surface of the tire, E1 is the modulus of the inner liner (approximately 5 MPa), h is the total thickness of the belt layer, and the exponent n is 2.5, indicating that the modulus increases non-linearly with height. This distribution helps reduce the tendency for interlayer delamination, especially under the huge torque generated during rapid acceleration or emergency braking, while still maintaining structural integrity.

[0054] (3.2) Laying the main reinforcement layer to enhance the circumferential constraint capability After applying a thin layer of adhesive to the surface of the buffer transition layer, a continuous winding process is used to tightly arrange 50 mm wide ultra-high molecular weight polyethylene fiber strips along the tire circumference, with seamless connections between adjacent strips, achieving a total coverage of 100%. This fiber strip undergoes a special impregnation treatment, containing a styrene-butadiene copolymer impregnating agent, ensuring good compatibility with the surrounding rubber. Due to its highly oriented molecular chains, its tensile strength reaches 3.5 GPa, and its density is only 0.97 g / cm³, far superior to traditional steel wire materials. The main function of this layer is to provide strong circumferential tensile force under the internal pressure of the tire, preventing the tire body from bulging due to excessive circumferential stress. According to the thin-walled cylinder theory, the circumferential stress generated by the internal air pressure p on the tire wall... Represented as: ; Where r is the tire's inner radius and t is the effective sidewall thickness. When p = 250 kPa, r = 0.3 m, and t = 0.012 m, the calculated values ​​are... Megapascals. The tensile strength provided by the main reinforcing layer far exceeds this value. Even if some fibers break, the remaining fibers can still withstand the required stress, demonstrating good damage tolerance characteristics.

[0055] (3.3) Install an anti-flow isolation layer to block the crack propagation path. A 1.0 mm thick layer of aramid bias-ply fabric is laid on top of the main reinforcing layer at an angle of ±70°, i.e., tilted 70 degrees relative to the tire circumference. This angle is chosen based on fracture mechanics analysis. When cracks propagate radially, they frequently cross the fiber direction, requiring additional energy each time to cut the fibers or disrupt the interfacial bonds, thus significantly slowing down crack propagation. Experiments show that this structure can reduce the crack propagation rate by approximately 60% compared to isotropic materials. Furthermore, this layer also acts as an insulator, preventing external moisture or contaminants from seeping in through tread cracks and spreading along the interlayer interfaces into the tire carcass, causing more widespread structural degradation. Since the main reinforcing layer in the previous step is a unidirectional structure lacking lateral strength, the addition of this layer forms a truly two-dimensional reinforcement system, improving overall impact resistance and stability.

[0056] (3.4) Local pressure curing of the belt layer To ensure a tight bond between the multi-layered belt structure and prevent slippage or bubbling during subsequent processing, a programmable hot press roller is used to apply pressure zone by zone after all layers are stacked. The hot pressing temperature is set at 110 degrees Celsius, the pressure at 0.4 MPa, and the travel speed at 2 meters per minute, with two round trips. This temperature is below the threshold for complete rubber vulcanization but sufficient to activate the active ingredients in the adhesive, promoting molecular chain diffusion and the formation of cross-linking points. The pressure serves to expel residual air and force each fiber layer to fully contact the rubber compound, reducing interfacial porosity. After pressing, the belt is allowed to cool to room temperature. At this point, the belt layers have formed a dense whole, and its interlaminar shear strength has been tested to reach over 1.8 MPa, sufficient to withstand the complex stress environment in subsequent molding processes.

[0057] Step 4: Prepare and integrate a self-sealing elastic filler layer Addressing the core issue of rapid gas leakage after a tire puncture, this step involves constructing a self-sealing elastic filler layer with viscoelastic properties on the inner surface of the tire's internal cavity. Under normal conditions, this material exists as a soft gel with low modulus and high ductility, not affecting the tire's normal rolling performance. However, upon localized puncture, the material rapidly flows around the damaged channel and encapsulates the foreign object, forming a temporary seal to prevent large-scale gas escape. This filler layer, 3.0 mm thick, is a blend of hydrogenated nitrile butadiene rubber (HNBR) and liquid polybutadiene plasticizer, supplemented with nano-silica as a reinforcing filler, giving it shear-thickening behavior—that is, a significant increase in viscosity with increasing external force rate, which is beneficial for handling high-speed penetration events. The filler layer is uniformly coated onto the inner wall of the inner liner using a centrifugal casting process, and then subjected to low-temperature cross-linking treatment to form a stable network.

[0058] (4.1) Formulate a self-sealing adhesive with shear thickening properties Hydrogenated nitrile butadiene rubber (NBR) with an acrylonitrile content of 38% and a hydrogenation degree greater than 95% was selected as the matrix material, exhibiting excellent oil resistance and temperature stability. It was mixed with hydroxyl-terminated liquid polybutadiene (PPT) with a molecular weight of 2000 at a mass ratio of 6:4 and kneaded in a Banbury mixer at 80°C for 20 minutes to allow the plasticizer to fully swell within the rubber network. Subsequently, 12% of precipitated nano-silica (specific surface area 200 m² / g) was added, and kneading continued for 10 minutes to ensure uniform particle dispersion. The nanoparticles, rich in silanol groups, can form hydrogen bonds with rubber segments, maintaining material flowability under static conditions. However, when high-speed shear is applied externally, the hydrogen bonds between particles break and rearrange, causing a sudden increase in system viscosity, exhibiting typical shear thickening behavior. Its apparent viscosity... With shear rate The relationship can be approximated by the Herschel-Bulkley model: ; in, For shear stress, Let be the yield stress (approximately 80 Pa), K be the consistency coefficient, and n be the flow index (here, n < 1, indicating a pseudoplastic fluid). When Exceeding a certain threshold (e.g., 1000s) -1 ), It can rapidly increase from 1,000 centipoise to over 100,000 centipoise, which is equivalent to changing from a liquid to a near-solid state, thus effectively sealing the slender channels formed by high-speed puncture.

[0059] (4.2) Uniform coating of the inner cavity is achieved by using centrifugal casting process. The prepared self-sealing adhesive is preheated to 50 degrees Celsius to reduce its initial viscosity and facilitate flow. The semi-finished tire carcass, completed in step three, is then mounted on a rotatable support, sealed at one end and connected to a supply pipe at the other. The motor is started, causing the tire carcass to rotate uniformly around a horizontal axis at 30 revolutions per minute, while the adhesive is slowly injected into the tire cavity via a metering pump. Under centrifugal force, the adhesive is thrown outwards along the inner wall, forming a uniform annular liquid film. Due to the constantly changing directions of gravity and centrifugal force, the liquid undergoes multiple spreading and leveling processes during rotation, eventually achieving a uniform distribution. After injection, rotation continues for 40 minutes until the surface ripples completely disappear, at which point rotation is stopped. The measured maximum deviation of the inner wall adhesive layer thickness does not exceed ±0.3 mm, meeting design requirements. Compared to manual scraping or spraying, this method better ensures the uniformity of large-area coating, avoiding localized thinning or accumulation.

[0060] (4.3) Perform low-temperature cross-linking treatment to form a three-dimensional network structure To ensure the self-sealing layer possesses the necessary cohesive strength to prevent it from detaching during rolling, moderate cross-linking is required. The coated substrate is placed in an oven and heated at 60°C for 12 hours, during which nitrogen gas is introduced for protection against oxidation. A bismaleimide derivative is used as the cross-linking agent, added at 1.5% of the total rubber composition. Its active groups at both ends can undergo Michael addition reactions with the double bonds or amino groups on the HNBR segments, gradually constructing a three-dimensional network. The purpose of low-temperature, long-duration treatment is to avoid violent reactions that could cause volume shrinkage or bubble formation. The final cross-linking density is approximately 0.08 mol / m³, corresponding to a gel content of over 92%. At this point, the material retains high segmental mobility, macroscopically exhibiting a soft elastomer with an elongation of up to 800%, but it responds rapidly to rapid disturbances and produces a localized hardening effect.

[0061] (4.4) Inspect the integrity of the self-sealing layer and repair defective areas. After cross-linking is completed, a comprehensive visual inspection and infrared thermal imaging scan of the self-sealing layer are performed to identify defects such as missed coating, pores, or impurities. For small defects with a diameter of less than 5 mm, manual filling is carried out using the same formula of repair adhesive, and local heating to 50 degrees Celsius with a hot air gun is used to promote fusion. For large uneven areas, the original coating must be removed and the casting process must be repeated. Qualified products should meet the following conditions: the adhesive layer is continuous and uninterrupted on any cross-section, the thickness is within the range of 3.0 ± 0.3 mm, and it can spontaneously seal holes with a diameter of no more than 6 mm in a simulated puncture test. Only by passing this test can the self-sealing function be reliably established, and then proceed to the final vulcanization and assembly stage.

[0062] Step 5: Install wear-resistant tread and construct drainage guide groove structure On the outer side of the tire carcass, which has already integrated multi-layer reinforcement and self-sealing functions, the final wear-resistant tread is bonded together, and a groove system with directional drainage function is simultaneously processed. This tread is made of high-silica tread rubber, possessing excellent wet grip and wear resistance. Its formula contains 70 parts silica (based on 100 parts rubber), and chemical bonding with the rubber matrix is ​​achieved through a silane coupling agent, thereby reducing rolling resistance and improving adhesion on icy and snowy roads. The tread profile is optimized according to the vehicle's axle load distribution, with a slightly convex central area to reduce peak ground pressure and extend service life. Simultaneously, a crisscrossing network of grooves is cut into the tread surface. The main grooves are 8.5 mm deep and 6 mm wide, extending continuously along the circumference for rapid drainage of water in the forward direction; the lateral grooves are arranged at a 30-degree angle, forming a spiral drainage path to enhance lateral water film breaking capacity. The entire tread is firmly bonded to the underlying belt layer through thermoforming, ensuring no delamination or edge lifting occurs during high-speed driving.

[0063] (5.1) Prepare high-silica tread compound and perform preforming extrusion Based on the self-sealing layer structure constructed in step four, a tread material that is both wear-resistant and has good adhesion needs to be matched to its exterior. A solution-polymerized styrene-butadiene rubber (SSBR) and natural rubber blend system was selected in a ratio of 7:3. The SSBR molecular chain contains vinyl side groups, which is beneficial for interaction with fillers. The mixed rubber was put into an internal mixer, and highly dispersible precipitated silica (specific surface area 180 m² / g), vulcanizing agent, accelerator, and silane coupling agent bis[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) were added sequentially. The total addition amount was 70 g of silica and 8 g of TESPT per 100 g of raw rubber. The mixing temperature was controlled below 140 degrees Celsius to prevent filler agglomeration. After a three-stage mixing process, a uniformly dispersed tread masterbatch was obtained. The masterbatch was then fed into a screw extruder with a die shape corresponding to the equatorial profile of the tire, and continuously extruded into annular strips with a constant cross-section. The width was slightly larger than the final tread requirement to facilitate subsequent trimming. Maintain a stable extrusion speed during the preforming process to avoid uneven thickness caused by flow fluctuations, which would affect the dynamic balance characteristics.

[0064] (5.2) Heat-press the tread strips onto the surface of the belt layer. The annular tread strip obtained in step 5 (5.1) is hoisted above the semi-finished tire body and precisely fitted into the outer edge of the belt layer using an automatic centering device. It is then moved into a hot press molding machine with raised grooves on the inner wall of the mold corresponding to the target groove layout. After closing the mold, a pressure of 0.6 MPa is applied, and heat-conducting oil at 130 degrees Celsius is introduced for 15 minutes. Under these conditions, the tread compound softens and flows, fully filling the mold cavity, and undergoes physical penetration and partial cross-linking reaction with the lower anti-flow isolation layer, forming a strong and tough interface. Since the belt layer laid in step 3 provides sufficient rigid support, the tread will not collapse locally under pressure, ensuring the groove forming accuracy. After hot pressing, the mold is opened and the tread is removed. At this point, the tread is initially shaped but not yet fully vulcanized, still possessing a certain degree of machinability, facilitating the next stage of precision cutting.

[0065] (5.3) Laser engrave the main groove and set the spiral drainage path. To achieve efficient drainage, a high-power fiber laser is used to perform non-contact grooving on the tire tread surface. The laser wavelength is 1064 nanometers, the pulse frequency is 100 kHz, the single pulse energy is 0.5 millijoules, and the scanning speed is 8 meters per second. First, four equidistant straight main grooves are cut along the tire circumference, with a depth controlled at 8.5 mm and a rounded bottom with a radius of 1.2 mm to reduce stress concentration. Then, transverse grooves are machined, with an angle of 30 degrees to the circumference and a spacing of 40 mm, forming an alternating left-hand and right-hand spiral structure. This layout allows the grooves to act like propellers, pushing water from the contact area to both sides as the vehicle rolls forward, significantly reducing the risk of hydroplaning. The advantages of laser processing are that it involves no mechanical contact, avoiding rubber tearing or burr problems that may occur with traditional milling, and the groove geometry parameters can be flexibly adjusted through programming to adapt to the needs of different application scenarios.

[0066] (5.4) Perform surface micro-texturing treatment on the grounding imprint area. To further enhance wet grip performance, a surface micro-texturing treatment was implemented in the central contact patch area of ​​the tire tread. Using a micro-blasting device, alumina particles with an average diameter of 50 micrometers were sprayed at a pressure of 0.2 MPa onto a specific area of ​​the tread, covering the middle 60% of the tire's contact patch length. This process created numerous pits with a diameter of approximately 100-200 micrometers on the tread surface, with a density of approximately 120 pits per square centimeter. These microstructures form "micro-anchoring points" between the tire and the road surface, effectively piercing the water film, especially under thin water conditions, increasing the actual contact area between the rubber and asphalt. The frictional force expression is derived from the Archard wear model: ; in, For friction, Let W be the coefficient of friction, W be the normal load, H be the material hardness, and A be the coefficient of friction. r This represents the actual contact area. Through micro-texturing, A r Compared to smooth surfaces, the performance is improved by approximately 40%, and it can maintain a high level even in the presence of lubricating media. Value. This treatment is limited to non-groove areas, does not affect overall drainage efficiency, and avoids excessively weakening the tread structure strength.

[0067] Step 6: Perform final overall vulcanization and three-dimensional shaping. After all functional layers have been assembled, the entire tire undergoes a final high-temperature, high-pressure vulcanization process to ensure complete cross-linking of all rubber components, forming a unified elastic network structure. This process not only determines the tire's final mechanical properties but also plays a decisive role in its geometric accuracy, dynamic balance, and durability. Vulcanization is carried out in a specialized drum mold, where the inner wall precisely replicates the target tread pattern, including main grooves, lateral grooves, and micro-texture details. By precisely controlling the temperature gradient and pressure distribution, heat is ensured to be evenly conducted from the outside in, avoiding excessive differences in vulcanization levels between the inner and outer layers that could lead to residual stress accumulation. After vulcanization, the tire is slowly cooled to reduce deformation caused by thermal shrinkage and ensure the dimensional stability of the finished product.

[0068] (6.1) Place the assembled tire blank into a precision vulcanizing mold and seal and pressurize it. The completed tire blank from step five is carefully placed into a metal vulcanizing mold preheated to 170 degrees Celsius. The mold consists of upper and lower mold plates and a central bladder, which is secured by a hydraulic locking mechanism after closing. High-pressure saturated steam is injected into the bladder, raising the pressure to 2.0 MPa, ensuring the inner wall of the tire adheres tightly to the inner side of the tread and transmitting pressure to the interfaces of each layer. An electric heating belt surrounds the outside of the mold to maintain a constant temperature. Due to the good pre-forming achieved in previous steps, the gap between the tire blank and the mold cavity is extremely small at this point, typically not exceeding 1 mm, which facilitates uniform pressure transmission. After sealing, the timing program is started, and the vulcanization cycle officially begins. The key to this stage is preventing air from accumulating between layers or at the root of the grooves. Therefore, a brief venting process is incorporated into the initial pressurization phase—that is, the pressure is first increased to 1.5 MPa, maintained for 30 seconds, then briefly depressurized, and then repressurized to the working pressure, repeated twice to expel any trapped gases.

[0069] (6.2) Set a stepped heating curve to achieve uniform crosslinking. To avoid uneven vulcanization or thermal stress cracking caused by excessive internal and external temperature differences, a staged heating strategy is adopted. Initially, the mold temperature is maintained at 170 degrees Celsius for 10 minutes to allow heat to penetrate towards the center of the tire carcass. Subsequently, the temperature is gradually increased to 195 degrees Celsius at a rate of 2 degrees Celsius per minute until the set value is reached and maintained at this temperature for 18 minutes. This temperature range corresponds to the optimal reactivity window of the vulcanization system, promoting the synergistic effect of sulfur and accelerators to form a polysulfide cross-linked network. Estimated using the Arrhenius equation, the vulcanization reaction rate approximately doubles for every 10 degrees Celsius increase in temperature. ; Where k is the reaction rate constant, E a Let K be the activation energy (approximately 80 kJ / mol), R be the gas constant, and T be the absolute temperature. When T increases from 443 K to 468 K, k increases by nearly 1.9 times, indicating that the later high-temperature stage can accelerate the deep cross-linking process. Stepwise heating can ensure that the outer layer does not become sulfurized while ensuring that the inner layer is fully vulcanized, thus achieving consistent overall performance.

[0070] (6.3) Monitor the degree of vulcanization and determine the time of endpoint arrival. During vulcanization, built-in sensors monitor capsule pressure and mold temperature in real time, and a portable vulcanizer collects torque change data of the edge rubber compound. When the rubber transitions from a plastic to an elastic state, its shear modulus increases significantly, reflected in the vulcanization curve as a stabilizing torque value. The optimal vulcanization time is defined as the time required for the torque to rise to 95% of its maximum value. Once this point is confirmed, heating is immediately stopped, and preparation for the cooling stage begins. Prematurely ending vulcanization results in insufficient crosslinking density, affecting heat aging resistance; excessive vulcanization causes the rubber to become brittle, reducing fatigue resistance. Therefore, accurately determining the endpoint is crucial for ensuring product quality. In this embodiment, based on multiple parameters, the optimal vulcanization time is approximately 28 minutes.

[0071] (6.4) Implement slow cooling demolding to reduce residual stress accumulation. After vulcanization, the heating source is turned off, and the cooling water circulation system is turned on to reduce the mold temperature from 195 degrees Celsius to below 80 degrees Celsius at a rate of 1.5 degrees Celsius per minute. Slow cooling allows the rubber network sufficient time to relax during shrinkage, preventing tensile stress or warping caused by excessively rapid local cooling. Once the temperature has dropped to a safe range, the bladder pressure is released, the mold is opened, and the finished tire is removed. At this point, the tire has a complete structure: from the inside out, it consists of a self-sealing elastic filler layer, an inner liner layer, a carcass ply layer, an annular retaining skeleton, a stress-dispersing mesh, a buffer transition layer, a main reinforcement layer, an anti-slippage isolation layer, and the outermost wear-resistant tread. All layers are tightly bonded, with no obvious signs of interface slippage, a clear overall outline, and a full tread pattern, meeting design requirements.

[0072] Step 7: Conduct dynamic equilibrium calibration and structural integrity verification Although vulcanized tires have a basic shape and structure, they may still have uneven mass distribution or local defects, affecting stability during high-speed operation. Therefore, dynamic balancing testing and correction are necessary to ensure the balance of inertial forces during rotation. Simultaneously, non-destructive testing is used to check for internal voids, delamination, or foreign object inclusions to confirm structural integrity. Only tires that pass both inspections can proceed to the final assembly process.

[0073] (7.1) Measure the mass eccentricity on the dynamic balancing machine and record the data. The finished product obtained in step six is ​​installed on a high-precision dynamic balancing test bench, filled with standard air pressure of 250 kPa, and rotated at a speed of 600 revolutions per minute to simulate actual driving conditions. The equipment collects radial and axial vibration signals through vibration sensors, decomposes them into main harmonic components through Fourier transform, and identifies the magnitude and phase angle of the imbalance. A sample was found to have a mass eccentricity of 18 g·cm on the equatorial plane, located at a counterclockwise angle of 45 degrees. This value exceeds the allowable threshold (12 g·cm), indicating that counterweight adjustment is required. The measurement results are automatically stored in the production database as a basis for subsequent traceability.

[0074] (7.2) Attach counterweights to light-weight locations to eliminate rotational vibration. Based on the imbalance parameters obtained in the previous step, a customized counterweight is attached to the rim contact area of ​​the corresponding phase. A lead-tin alloy material with a density of 9.8 g / cm³ is used; the counterweight is an arc-shaped sheet with a thickness of 2 mm and is fixed with high-strength pressure-sensitive adhesive. The bonding surfaces are cleaned before attachment to remove grease and dust. In this example, a 9-gram counterweight is used, installed at a 45-degree clockwise angle (i.e., lightly touching the opposite side), which theoretically can counteract the original eccentricity. The test bench is restarted for re-inspection, and the remaining imbalance is measured to have decreased to 6 g / cm³, within the acceptable range. The counterweight layout follows the principle of minimum usage to avoid additional weight affecting fuel economy.

[0075] (7.3) Use ultrasonic testing to detect the quality of internal interlayer bonding. To further confirm structural reliability, a comprehensive scan of the tire carcass was performed using pulse-echo ultrasonic testing. The probe frequency was 5 MHz, the coupling agent was glycerol, and the scanning step size was 5 mm, covering the entire area from the tire shoulder to the center of the tread. Under normal circumstances, ultrasound waves are reflected at the interfaces between layers, forming a regular echo sequence; if delamination or air bubbles are present, additional reflection peaks or acoustic shadowing areas will appear. The test revealed a tiny delamination near the equator, approximately 15 square millimeters in area, with a depth between the main reinforcing layer and the anti-channeling isolation layer. This area was marked as the area to be repaired. No abnormalities were found in the remaining areas, indicating that most interlayer bonding was good.

[0076] (7.4) Perform local hot pressing repair on the defective area and inspect it again. For the detected delamination area, a handheld infrared heater was used to locally heat the area to 120 degrees Celsius for 5 minutes, softening the rubber near the interface. A static pressure of 0.3 MPa was then applied and held for 10 minutes to promote re-bonding of the two layers. After cooling, ultrasonic testing was performed again; the original abnormal signal disappeared, and the echo spectrum returned to normal. A dynamic balancing test was then conducted after the repair, confirming that performance was unaffected. This treatment restored the overall structural integrity of the tire, meeting delivery standards.

[0077] Step 8: Packaging and protective layer and final inspection before delivery To prevent surface contamination or mechanical damage during transportation and storage, a peelable protective coating is sprayed onto the outer surface of the tire, followed by a final functional check. This coating dries to form a transparent film that dissolves in water without affecting normal use. Simultaneously, product identification, specifications, and customer order information are verified to ensure traceability. The final inspection covers multiple indicators, including appearance quality, dimensional tolerances, airtightness, and packaging standards; only after all standards are met can the tire be stored or shipped.

[0078] (8.1) Apply a hydrolyzable protective film to isolate external pollution. A polyvinyl alcohol (PVA) aqueous solution with a concentration of 8% was selected as the protective coating, with a small amount of defoamer and wetting agent added to improve its workability. The coating was evenly atomized and sprayed onto the tire tread and sidewall surfaces using an automatic spray gun, with a thickness controlled at approximately 0.1 mm. The PVA molecular chain contains a large number of hydroxyl groups, which can form a dense hydrogen bond network after drying, effectively blocking dust, oil, and UV rays. More importantly, this film layer can be completely dissolved within 10 minutes after immersion in water, eliminating the need for manual removal and greatly simplifying the process for end users. The spraying environment should be kept clean with a relative humidity below 60% to prevent the coating from absorbing moisture and wrinkling.

[0079] (8.2) Verify the accuracy of product identification and batch code. Inspect the molded product nameplate at a designated location on the tire sidewall to confirm it includes the following information: specifications (e.g., 205 / 55R16), load index (91V), speed rating, production date code, factory number, and certification mark. Use a barcode scanner to read batch data from the embedded RFID tag and compare it with the MES system records to verify that the material source and process parameters match. Any discrepancies are considered defective and must be returned for rework. Clear and complete labeling is fundamental to achieving full lifecycle management and facilitates subsequent quality tracking and recall management.

[0080] (8.3) Conduct an airtightness test to verify the long-term pressure holding capacity. The tire is mounted on a sealing test fixture, inflated with 300 kPa nitrogen, and immersed in a water tank for 30 minutes, observing for continuous air bubbles. If no visible leakage is found, the pressure is maintained for 24 hours, with pressure values ​​recorded hourly. The average pressure drop rate is calculated and should be less than 5 kPa / day. This test simulates sealing performance under long-term parking conditions, ensuring the effectiveness of the barrier system formed by the self-sealing layer and the inner liner. Passing the test indicates that the tire has the ability to withstand slow punctures and natural seepage, and can maintain a sufficient driving distance after damage.

[0081] (8.4) Perform final visual inspection and complete standardized packaging. Quality inspectors visually inspect the tire against standard samples for uniform color, clear tread pattern, neat edges, and the presence of scratches, dents, or other surface defects. Qualified tires are wrapped in PE plastic bags, sealed at both ends, and placed on a dedicated pallet, with cardboard padding between each layer to prevent friction. The outer box is labeled with the product model, quantity, weight, and storage / transport markings such as "This Side Up" and "Keep Dry." After packaging, an outbound document is generated, and a quality report is uploaded to the cloud server, completing the entire manufacturing process. At this point, a new type of tire combining explosion-proof performance and driving safety is officially manufactured and ready for market use.

[0082] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A safety run-flat tire characterized by, The tire comprises, from inside to outside, a self-sealing elastic filling layer, an inner liner, a carcass ply, an annular limiting framework, a stress dispersion grid, a belt layer, and a wear-resistant tread; The self-sealing elastic filling layer is attached to the inner wall of the inner liner and is composed of hydrogenated nitrile rubber blended with liquid polybutadiene plasticizer and added with nano-silicon dioxide; The annular limiting framework is formed by splicing a plurality of arc-shaped metal segments into a ring structure and is located between the carcass ply and the stress dispersion grid, and the inside of the annular limiting framework is filled with light-weight damping composite material; The stress dispersion grid is laid on the annular limiting framework and is woven from aramid filaments; The belt layer comprises a cushioning transition layer, a main reinforcing layer, and a flow-channeling prevention isolation layer, the cushioning transition layer is located above the stress dispersion grid, the main reinforcing layer is composed of super-high molecular weight polyethylene fiber belts arranged closely along the circumferential direction of the tire, and the flow-channeling prevention isolation layer is located above the main reinforcing layer; The wear-resistant tread is provided with main grooves and inclined transverse grooves on the surface, and the central area of the tread is subjected to surface micro-texturing treatment.

2. A safety run-flat tire according to claim 1, wherein The self-sealing elastic filling layer is internally distributed with nano-silicon dioxide particles, the surface of the nano-silicon dioxide particles is rich in silicon hydroxyl groups, and the silicon hydroxyl groups form a reversible cross-linking network with hydrogenated nitrile rubber segments through hydrogen bonding.

3. A safety run-flat tire according to claim 1, wherein Each arc-shaped metal segment of the annular limiting framework has a U-shaped groove structure, the groove depth is 8 mm, the bottom circular arc radius is 2 mm, the two side wings are inclined outward by 5 degrees, a gap of 2 mm is left between adjacent framework segments, a plurality of micropores are formed on the surface of the framework, and a silane coupling agent primer is coated on the micropores.

4. The safety run-flat tire of claim 1, wherein, An intermediate adhesive layer is arranged between the flow-channeling prevention isolation layer and the main reinforcing layer, the adhesive layer contains a styrene-butadiene copolymer component, the central ground footprint area of the wear-resistant tread is distributed with dimples with a diameter of 100-200 microns, and the density is 100-150 per square centimeter.

5. A process for the preparation of the safety run-flat tire according to any one of claims 1-4, characterized in that, The method comprises the following steps: S1: wrapping a halogenated butyl rubber sheet on a rotating forming drum to form an inner liner, and performing plasma bombardment treatment on the outer surface of the inner liner; Then, a carcass ply is wound on the outer part of the inner liner, and a pressure roller is rolled after applying a pre-tightening force; Subsequently, bead wires are embedded at both ends of the carcass, and a reinforcing core strip is installed; finally, the assembled tire blank is subjected to primary vulcanization and shaping to obtain a basic carcass; S2: pre-preparing arc-shaped framework segments, filling damping composite material in the inner cavity of the framework segments after surface treatment, then placing the framework segments one by one on the designated area of the outer surface of the basic carcass, bonding by using an adhesive, and forming a continuous ring structure by using a connecting piece; then, laying an orthogonal grid cloth woven from aramid filaments on the framework as a stress dispersion grid; S3: after applying glue on the surface of the stress dispersion grid, attaching a steel cord ply as a cushioning transition layer; Then, coating adhesive on the surface of the cushioning transition layer, winding super-high molecular weight polyethylene fiber belts to form a main reinforcing layer; laying aramid bias cloth as a flow-channeling prevention isolation layer on the main reinforcing layer; finally, locally pressurizing and curing the belt layer; S4: preparing a self-sealing glue, and installing a semi-finished carcass on a rotatable support; The motor is started to rotate the tire body at a constant speed, and the self-sealing rubber compound is injected into the tire cavity, and is uniformly coated on the inner wall of the inner liner under the action of centrifugal force to form an annular liquid film with uniform thickness. S5: The tire body after coating is subjected to low-temperature crosslinking treatment to form a three-dimensional network structure; then the self-sealing layer is inspected and repaired; after confirmation of qualification, the assembled tire blank is placed into a curing mold for stepwise temperature increase vulcanization, and finally slow cooling and demolding to obtain a complete and shaped safety anti-blast tire.

6. The process of claim 5, wherein, In S1, the power of the plasma bombardment treatment is 300-400 watts for 40-50 seconds to increase the surface energy of the inner liner to 45-50 dynes / cm; the temperature of the primary vulcanization shaping is 150-160 degrees Celsius, the internal pressure is maintained at 1.5-2.0 MPa, and the heating is continued for 25-35 minutes.

7. The process of claim 5, wherein, In S2, the number of arc-shaped skeleton segments is 20-30, which are symmetrically distributed around the equatorial plane of the tire; the damping composite material filled in the skeleton cavity is mixed by hollow glass beads and epoxy resin in a weight ratio of 55-65:35-45; the skeleton segment placement position is limited within ±25-35 mm from the equator line.

8. The process of claim 5, wherein, In S3, the buffer transition layer is formed by two layers of steel cord in a ±25-35° cross manner; the width of the ultra-high molecular weight polyethylene fiber belt of the main reinforcing layer is 45-55 mm, and there is seamless joint between adjacent belt strips; the temperature of the local pressure curing is 105-115 degrees Celsius, the pressure is 0.35-0.45 MPa, and the walking speed is 1.5-2.5 meters per minute.

9. The process of claim 5, wherein, In S4, the self-sealing rubber compound is mixed by hydrogenated nitrile rubber and liquid polybutadiene in a mass ratio of 5.5-6.5:3.5-4.5, and 10-15% of nano silicon dioxide is added; the tire body rotation speed is 25-35 revolutions per minute, the rubber compound preheating temperature is 45-55 degrees Celsius, and the rotation coating time is 35-45 minutes.

10. The process of claim 5, wherein, In S5, the low-temperature crosslinking treatment temperature is 55-65 degrees Celsius, and the duration is 10-14 hours; the stepwise temperature increase vulcanization is first maintained at 165-175 degrees Celsius for 10-12 minutes, then increased to 190-200 degrees Celsius at a rate of 1.5-2.5 degrees Celsius per minute and kept constant for 16-20 minutes; the cooling stage is cooled at a rate of 1.0-2.0 degrees Celsius per minute to 75-85 degrees Celsius.

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