Improved manufacturing process for vehicle wheel RIMS with precise width control

Abstract

The present disclosure provides an improved process for manufacturing vehicle wheel rims with controlled rim width and enhanced dimensional precision. The process starts by coiling a metal strip and welding the ends to form a continuous hoop, followed by trimming, re-rounding, and sanding for a smooth profile. Flaring and forming operations using hydraulic presses shape the flange, while well base spinning reduces thickness and volumetrically increases width. Sequential roll forming operations include an initial step to partially shape the tyre seat and gutter, followed by a final roll forming step for precise dimensioning. Precision machining of the gutter end controls rim width variation within -0.5mm to +0.5mm. The process concludes with diameter adjustment, valve slot piercing, and marking for traceability. This method achieves material savings of up to 2.5 kg, reduces production costs, and enhances tire fitment quality, providing substantial advantages over conventional rim manufacturing methods.

Description

IMPROVED MANUFACTURING PROCESS FOR VEHICLEWHEEL RIMS WITH PRECISE WIDTH CONTROLFIELD

[0001] The present disclosure relates to the field of vehicle wheel rim manufacturing, focusing on an improved process aimed at precise control of rim width, enhancing the accuracy and consistency of the final product.BACKGROUND AND PRIOR ART

[0002] Vehicle wheel rim manufacturing involves a variety of well-established methods, particularly for commercial vehicle rims, where the production has predominantly relied on the Cold Press Spun Rim (CPSR) process. Although widely adopted, certain conventional methods, including CPSR, often encounter challenges in achieving consistent rim width. Variations in rim width can adversely affect the fitment, performance, and safety of the final product. The CPSR method combines both press forming and roll forming steps, which may introduce dimensional inconsistencies during the manufacturing process.

[0003] Typically, the CPSR process begins with coiling a metal strip, followed by preparatory steps such as flattening the ends for butt-welding. Flash butt welding is performed to join the coiled ends into a continuous band, and excess material (flash) is trimmed off. The flattened section is re-rounded, and edge clipping is conducted to ensure uniformity. Any residual flash is sanded away, followed by pre-formation and flaring of the gutter using a hydraulic press. The flange is then formed, and the gutter undergoes roll forming to achieve the final dimensions.

[0004] One notable challenge in the conventional CPSR process is the high pressure required during gutter formation, often necessitating hydraulic presses with capacities up to 2000T. This significant pressure can lead to uneven materialdistribution, dimensional inconsistencies, and increased wear on equipment, resulting in operational inefficiencies and higher energy consumption.

[0005] In subsequent stages, the thickness at the well region of the rim is reduced through a well base spinning process, which volumetrically increases the width of the rim. The tire seat region is rolled to meet the specified drawing dimensions, and the rim undergoes a contraction step to achieve the correct overall diameter. However, maintaining precise dimensional control throughout these stages remains a significant challenge.

[0006] A key drawback of the existing CPSR process is that the well base spinning step is performed after the gutter has been fully formed. This sequencing often results in substantial variations in rim width, highlighting a lack of control and precision. Additionally, the combined use of press forming and roll forming, along with the high-pressure requirements for gutter formation, adds complexity and prolongs production time, increasing costs and energy consumption. The inability to manage rim width variation until after gutter formation leads to material wastage and inefficient resource utilization, adversely impacting production efficiency and sustainability.

[0007] Therefore, there is a need for an improved manufacturing process that effectively addresses the issues of rim width variation and enhances control and precision throughout the production stages. The present disclosure introduces such a process, designed to minimize rim width variation, reduce material usage, and lower production costs. By overcoming the limitations of the conventional CPSR process, the disclosed method significantly enhances product quality, consistency, and overall manufacturing efficiency, offering a more sustainable and cost-effective solution.OBJECTS

[0008] Some of the objects of the present disclosure are described herein below:

[0009] An object of the present disclosure is to provide minimized rim width variation compared to the existing methods, significantly improving product consistency.

[0010] Another object of the present disclosure is to achieve an overall weight reduction of the wheel rim and the material used, thereby contributing to greater vehicle efficiency.

[0011] Yet another object of the present disclosure is to enhance the overall quality and performance of the wheels by reducing dimensional variation and increasing manufacturing precision.

[0012] Still another object of the present disclosure is to provide a substantial reduction in process costs and energy consumption, thus improving the economic viability of the manufacturing process.

[0013] Yet another object of the present disclosure is to utilize roll forming operations exclusively for gutter formation, ensuring consistent structural integrity throughout the process.

[0014] Still another object of the present disclosure is to implement well base spinning before gutter formation, enhancing machining precision and control.

[0015] The other objects and advantages of the present disclosure will be apparent from the following description when read in conjunction with the accompanying drawings, which are incorporated for illustration of preferred embodiments of the present disclosure and are not intended to limit the scope thereof.SUMMARY

[0016] In view of the foregoing, embodiments herein provide an improved process for manufacturing vehicle wheel rims with precise rim width control.

[0017] In accordance with an embodiment, the present disclosure relates to an improved process for manufacturing vehicle wheel rims that may offer enhancedcontrol over rim width and improved dimensional precision. The process can involve coiling a metal strip to form a cylindrical band, followed by welding the ends to create a continuous hoop. The welded band may undergo steps such as trimming, re-rounding, edge clipping, and sanding to achieve a uniform profile.

[0018] One aspect of the process may include flaring one end of the hoop outwardly using a hydraulic press, with an applied force ranging from 500T to 600T. Further, expansion of the hoop may enable forming a well base. A subsequent forming operation using a press force of 1500T to 2000T may define a precise flange. The well base spinning operation may then be performed to reduce the thickness at the well base, increasing the width volumetrically and optimizing material distribution.

[0019] Another feature of the process can involve precision machining of the gutter end to remove excess material, which may help in controlling the rim width variation within a range of -0.5mm to +0.5mm. This step can contribute to improved dimensional accuracy and reduced need for post-production adjustments.

[0020] The process may further include an initial roll forming operation (RF1) with a force range of 20T to 80T, partially shaping the tyre seat and gutter regions. This can be followed by a second roll forming operation (RF2), applying a force ranging from 50T to 100T to finalize the shape of these regions. The use of controlled rolling forces may help in achieving precise dimensions and minimizing residual stress.

[0021] Additionally, the process can incorporate a contraction step to adjust the rim diameter by 0.5% to 2%, ensuring compliance with specified design requirements. The final steps may include valve slot piercing and the application of identification markings for traceability. The process can achieve significantreductions in material usage, improved fitment quality, and enhanced overall performance of the wheel rim.

[0022] The disclosed process may address common issues associated with conventional methods, such as rim wobble and excessive rim width variations, while offering potential cost savings and improved manufacturing efficiency. By utilizing efficient material usage and simplified equipment requirements, the process can deliver a more consistent, high-quality wheel rim with reduced production and energy costs.

[0023] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.BRIEF DESCRIPTION OF DRAWINGS

[0024] The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.

[0025] Fig. 1 illustrates a wheel rim from prior art, manufactured using the existing CPSR process, showing significant variation in rim width with less precise control;

[0026] Fig. 2 illustrates a sectional view of the initial stage of the process for manufacturing a vehicle wheel rim, focusing on the coiling and preparation of the metal strip, according to an embodiment herein;

[0027] Fig. 3 illustrates the flange flare band expansion process of a wheel rim, where the flange is flared, and the band is expanded to the required size for spinning using a hydraulic press, according to an embodiment herein;

[0028] Fig. 4 illustrates the flange forming process of the wheel rim, where the flange is formed using a hydraulic press, according to an embodiment herein;

[0029] Fig. 5 illustrates a well base spinning process, wherein the thickness at the well region is reduced, and the rim width is increased volumetrically, according to an embodiment herein;

[0030] Fig. 6 illustrates the gutter end machining process of the wheel rim, where rim width variation is minimized, according to an embodiment herein;

[0031] Fig. 7 illustrates the first roll forming operation in the tyre seat region and gutter portion, according to an embodiment herein;

[0032] Fig. 8 illustrates the second roll forming operation in the tyre seat region and gutter portion, according to an embodiment herein;

[0033] Fig. 9 illustrates a flow chart detailing the key steps of the manufacturing process, according to an embodiment herein; and

[0034] Fig. 10 illustrates a side view of a vehicle wheel rim, showing enhanced control over width variation, demonstrating a key aspect of the present process innovation, according to an embodiment herein.LIST OF NUMERALS100 - Sectional view of the wheel rim showing the rim width variation from the top rim to the bottom rim (Prior art).201 - Metal strip used for coiling301 - Wheel rim302 - Flange flare401 - Flange portion501 - Well base region601 - Guter end machining701 - Pre-forming guter801 - Flange edge802 - Guter portion900 - Flow chart of the method of manufacturing the wheel rims1000 - Final sectional view of the wheel rim showing the minimized rim width variation achieved by the disclosed processDETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be constmed as limiting the scope of the embodiments herein.

[0036] Fig. 1 illustrates awheel rim 100 manufactured using a conventional Cold Press Spun Rim (CPSR) process, highlighting the typical issues observed in the prior art, particularly rim width variation. The CPSR process generally involves coiling a metal strip, followed by but-welding, trimming excess flash, and shaping the rim using high-pressure hydraulic presses. Despite these steps, the process frequently results in significant rim width inconsistencies, as shown in Fig. 1. These variations can impact the precision, fitment, and performance of the final product, underscoring the need for a more controlled manufacturing process.

[0037] As mentioned above, there is a need for a manufacturing method for vehicle wheel rims that effectively eliminates rim width variation, therebyimproving precision and control. In particular, there is a need for an improved process that effectively minimizes rim width variation and enhances control and precision. This improved process should facilitate significant reductions in material usage, production time, and energy consumption, ultimately lowering production costs. The embodiments herein achieve this by providing an improved process should enhance product quality, consistency, and overall manufacturing efficiency, making it a more sustainable and cost-effective option. Referring now to the drawings, FIGS. 2 through 10, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.

[0038] Fig. 2 illustrates a sectional view 200 of a metal strip fixed onto a machining tool for the coiling process, according to an embodiment. In this step, a metal strip is coiled into a cylindrical shape to form a coil band. The ends of the coiled band are aligned and flattened to create smooth surfaces in preparation for welding. Tack welding is performed to temporarily secure the flattened ends together before proceeding with the main welding operation. Flash butt welding is used to join the aligned ends, resulting in a continuous and strong hoop. Excess flash material is removed from the welded joint through a trimming operation, which helps maintain a uniform profile. The formed hoop undergoes a re-rounding process to restore the cylindrical shape, followed by edge clipping to eliminate any remaining flash material along the edges. The final finishing step involves sanding the welded region to achieve a smooth and even surface, ensuring uniformity and preparing the hoop for subsequent forming processes. The described steps may be adjusted or varied based on specific design requirements and the capabilities of the tooling equipment used.

[0039] Fig. 3 illustrates a sectional view 300 of the flange flare band expansion process of a wheel rim, according to an embodiment. In this step, one end of the hoop is expanded outwardly through a flaring operation to form a flared end. The flaring is executed using a hydraulic press applying a force ranging from 500T to 600T. This flaring operation increases the diameter of the hoop, creating the flared end, and simultaneously expands the band to form a well base. The described process may be adjusted or modified based on specific design requirements and tooling capabilities.

[0040] Fig. 4 illustrates a sectional view 400 of the flange forming process of the wheel rim, according to an embodiment. This stage involves the shaping of the flared end through the application of force using a hydraulic press. The hydraulic press, with a force capacity ranging from 1500T to 2000T, is employed to form the flange, defining the final shape and dimensional profile required for the wheel rim. The described process may be adapted or modified depending on specific design requirements and the specifications of the wheel rim.

[0041] Fig. 5 illustrates a sectional view 500 of the well base spinning process, according to an embodiment. In this stage, the spinning operation is performed specifically at the well base region of the hoop. The spinning process involves the application of rotational force, which reduces the thickness of the material at the well base. This reduction in thickness leads to a volumetric expansion of the well base, effectively increasing the width of the wheel rim.

[0042] The well base spinning operation contributes to optimized material distribution, resulting in a lighter wheel rim while preserving structural strength. By achieving a uniform thickness and width through this process, the well base spinning helps enhance the balance and fitment quality of the wheel rim. Thedescribed spinning process may be adapted or modified based on specific design requirements and the material properties used in the wheel rim construction.

[0043] Fig. 6 illustrates a sectional view 600 of the gutter end machining process of the wheel rim, according to an embodiment. This stage involves precision machining performed specifically at the gutter end of the rim. The machining operation focuses on removing excess material from the gutter region to achieve a consistent and uniform rim profile. The process addresses residual width variations that may have been introduced during the well base spinning stage, effectively minimizing these variations. The controlled removal of material through this step reduces the rim width variation to a range of -0.5mm to +0.5mm, significantly improving upon the typical variation of up to 8mm observed in conventional methods. By achieving this level of precision, the machining operation enhances the dimensional accuracy and fitment quality of the wheel rim. Additionally, the process contributes to material efficiency, resulting in a reduction of up to 1 kg in the finished product’s weight and an overall raw material savings of up to 2.5 kg. Key parameters influencing this process may include the depth of cut, feed rate, tool material, and the application of coolant. These parameters may be adjusted based on specific design requirements and the properties of the rim material to optimize performance and ensure the desired surface finish.

[0044] Fig. 7 illustrates a sectional view 700 of the first roll forming operation (RF1) in the tyre seat region and gutter portion, according to an embodiment. In this stage, partial rolling is applied to shape the tyre seat region and initiate the formation of the gutter. The first roll forming operation serves as a preliminary shaping step, directing controlled material flow and helping to reduce residual stress in these critical areas. By performing partial rolling at this stage, the process sets the foundation for the subsequent final roll forming operation, allowing the rim toachieve near-final dimensions while minimizing potential distortions. The controlled deformation in RF 1 contributes to a smoother transition between the tyre seat and gutter regions, ensuring uniform material distribution and enhancing the structural integrity of the wheel rim. The roll forming in this step is executed using a roll former applying a force ranging from 20T to 80T. The applied force may be adjusted based on specific design requirements, the thickness of the rim material, and the desired final profile. This preliminary roll forming operation optimizes the shaping of the tyre seat and gutter, preparing the rim for precise dimensioning in the subsequent forming processes..

[0045] Fig. 8 illustrates a sectional view 800 of the second roll forming operation (RF2) in the tyre seat region and gutter portion, according to an embodiment. In this stage, the second roll forming operation finalizes the shaping of the tyre seat region and completes the full formation of the gutter. The precise application of force during RF2 corrects any residual variations that may have remained from the initial roll forming step (RF1), ensuring that the tyre seat region and gutter achieve the exact dimensions specified in the design. This operation is critical for establishing the final contour of these regions, enhancing the fitment accuracy and structural integrity of the wheel rim. The second roll forming operation is performed using a roll former with a force capacity ranging from 50T to 100T. The applied force may be varied based on the material properties of the wheel rim and specific design requirements. By employing controlled deformation during this step, RF2 ensures a smooth and consistent surface finish, minimizes dimensional deviations, and prepares the rim for final processing steps, such as diameter adjustment and surface finishing. The described parameters for RF2 may be adapted or modified based on specific manufacturing conditions and the desired final profile of the rim.

[0046] Referring to Fig. 9, a flowchart (900) illustrates a comprehensive process for manufacturing a vehicle wheel rim with precise rim width control, according toan embodiment. This process addresses the limitations of prior art methods and introduces innovative steps that enhance dimensional accuracy, reduce rim width variation, and optimize material usage.

[0047] The process begins with Step 901, where a metal strip is coiled onto a machining tool to form a cylindrical shape. The coiling step ensures that the strip maintains uniform tension throughout its length, providing a consistent base for the subsequent operations. Following this, the ends of the coiled strip are flattened, creating smooth surfaces that facilitate a strong and defect-free weld joint in the next step.

[0048] In Step 902, the flattened ends of the strip are temporarily joined using tack welding, followed by flash butt welding. Flash butt welding is selected for its ability to create a robust, seamless joint, minimizing the risk of defects at the weld seam. Excess flash material generated during welding is trimmed to maintain a uniform profde. The welded band is then subjected to re-rounding, restoring its cylindrical shape. Edge clipping follows, ensuring consistency along the entire circumference of the rim. Any residual flash material at the butt joint is removed through a sanding operation, achieving a smooth surface finish.

[0049] Step 903 involves the flange flare operation. A hydraulic press with a force capacity ranging from 500T to 600T is used to expand the flange edge outwardly, achieving the required size for the subsequent spinning operation. The flaring establishes the initial profile of the rim, allowing precise control in later stages of forming. The flange is then shaped using a hydraulic press with a force range of 1500T to 2000T. This shaping step is critical for ensuring the structural integrity and dimensional accuracy of the flange portion, which plays a key role in the overall fitment of the wheel rim.

[0050] In Step 904, the well base spinning process is performed. This step focuses on reducing the material thickness at the well region of the rim, leading toa volumetric increase in the width of the rim. The well base spinning is executed before the formation of the gutter, minimizing material stress and establishing a stable foundation that facilitates better control over rim width variations. This operation optimizes the distribution of material, enhancing the structural stability of the rim.

[0051] Step 905 introduces precision machining at the gutter end. This critical step involves removing excess material from the gutter region to address residual width variations left from the previous stages. The machining operation reduces the rim width variation to a controlled range of -0.5mm to +0.5mm, a significant improvement over the variations of up to 10mm observed in prior art methods. Additionally, the gutter end machining contributes to substantial material savings, achieving a weight reduction of 0.5 kg to 1 kg in the finished product and an overall raw material savings of 2.0 kg to 2.5 kg.

[0052] The process proceeds with Step 906, where the first roll forming operation (RF1) is conducted. This step uses a roll former applying a force in the range of 20T to 80T to partially shape the tyre seat region and the gutter portion. RF1 directs controlled material flow, reducing residual stress and preparing the tyre seat and gutter areas for the final shaping. The initial rolling ensures that these critical areas achieve near-final dimensions, minimizing potential distortions.

[0053] In Step 907, the second roll forming operation (RF2) is carried out. This final roll forming step applies a force capacity ranging from 50T to 100T, fully shaping the tyre seat region and gutter to their precise design specifications. The use of controlled force during RF2 corrects any remaining dimensional variations from RF1, ensuring that the final profile meets the required design standards. This step is essential for achieving the desired surface finish and maintaining consistent dimensions across the entire rim profile.

[0054] The process concludes with Step 908, involving diameter adjustment through a shrinking or contraction operation. This step fine-tunes the overall diameter of the rim, reducing it by 0.5% to 2% as needed to meet the specified design requirements. Following the diameter adjustment, the valve slot is pierced to create the necessary opening for the valve stem. Identification markings are then applied for quality control and traceability. A final precision machining operation is performed on the gutter profile, refining the shape to meet exact design specifications. This final step enhances the fitment of the rim, reduces wobble, and contributes to improved overall performance.

[0055] Fig. 10 illustrates a side view of a vehicle wheel rim, showcasing the precise control over rim width achieved through the improved manufacturing process, he figure highlights two key dimensions of the wheel rim: the top rim width (W) and the bottom rim width (X), representing the widths measured at distinct sections along the rim profile. The process ensures that the difference between the top width (W) and the bottom width (X), defined as (W - X), is maintained consistently within a tight range of -0.5mm to +0.5mm. This precise control of rim width variation contributes to a uniform and consistent profile across the entire rim circumference, enhancing the overall dimensional accuracy.

[0056] The ability to maintain the rim width difference within the range of - 0.5mm to +0.5mm signifies a substantial improvement over conventional manufacturing methods, such as the Cold Press Spun Rim (CPSR) process. In traditional processes, rim width variations can extend up to 10mm, leading to significant inconsistencies in the rim profile. The enhanced control provided by the improved process minimizes these variations, directly addressing common issues like rim wobble, which often arise from uneven material distribution during forming. By effectively reducing rim wobble, the process enhances the fitment accuracy of the wheel rim, ensuring proper seating of the tire. This improvementnot only reduces the risk of defects during tire installation but also contributes to better performance, improved safety, and extended service life of the wheel rim and tire assembly.

[0057] A main advantage of the present disclosure is the precise control of rim width variation within -0.5mm to +0.5mm, a significant improvement over the 10mm variations seen in conventional methods. This accuracy reduces issues like rim wobble, enhancing tire fitment and overall performance.

[0058] Another advantage is the reduction in material usage, with savings of up to 2.5 kg due to efficient removal of excess material from the gutter region. This leads to lower raw material consumption without sacrificing the structural integrity of the wheel rim.

[0059] The process effectively addresses residual variations from well base spinning by precision machining the gutter end, resulting in a cleaner, more accurate final product with minimal need for post-production corrections.

[0060] The use of a 2000T hydraulic press for flaring and a 50T roll former for initial rolling reduces equipment complexity, cuts maintenance costs, and optimizes the forming process for precise shaping.

[0061] The improved process also reduces production and energy costs by up to 50%, due to streamlined material usage and efficient machinery, making it a more cost-effective and sustainable manufacturing solution.

[0062] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purposeof description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

We Claim:

1. A process for manufacturing a vehicle wheel rim with controlled rim width and enhanced dimensional precision, the process comprising: coiling a metal strip to form a coil band; welding the ends of the coiled band to form a hoop; flaring one end of the hoop outwardly to form a flared end and expanding the hoop to create a well base; forming the flared end using a hydraulic press to define a flange; spinning at the well base of the hoop to reduce the thickness and increase the width of the well base by volumetric expansion; roll forming the opposite end of the hoop to define a tyre seat region and a gutter region of the wheel rim; machining the gutter end to reduce and control the variation in wheel rim width, refine the wheel rim profile, and enhance dimensional accuracy; wherein the wheel rim width variation across the circumference is controlled within a range of -0.5mm to +0.5mm, resulting in a uniform rim profile and improved fitment quality.

2. The process as claimed in claim 1, wherein the flaring is performed using a hydraulic press with a force ranging from 500T to 600T, and the forming of the flared end is performed with a force ranging from 1500T to 2000T.

3. The process as claimed in claim 1, wherein the spinning at the well base of the hoop is performed at a rotational speed ranging from 200 RPM to 500 RPM, and reduces the thickness of the well base by 10% to 20%, resulting in an increased width through volumetric expansion.

4. The process as claimed in claim 1, wherein the roll forming includes an initial roll forming step to partially shape the tyre seat region and the gutterregion, and a final roll forming step to fully define the tyre seat region and the gutter region.

5. The process as claimed in claim 4, wherein the initial roll forming step is performed using a roll former with a force range of 20T to 80T.

6. The process as claimed in claim 1, wherein the machining of the gutter end: enables to remove excess material from the gutter region to reduce rim width variation; achieves a weight reduction ranging from 0.5 kg to 3.5 kg; and improves the surface finish of the rim profile, enhancing dimensional accuracy and reducing the need for post-production adjustments.

7. The process as claimed in Claim 1, further comprising a step of adjusting the rim diameter through a contraction process, wherein the contraction reduces the overall diameter by 0.5% to 2%, ensuring the final rim dimensions meet the specified design requirements.

8. The process as claimed in Claim 1, further comprising a step of piercing a valve slot and applying identification markings on the rim, ensuring proper positioning of the valve slot and enhancing traceability of the wheel rim.

9. The process as claimed in Claim 1, further comprising: flattening the ends of the coiled band to create smooth surfaces for welding; and tack welding the flattened ends to temporarily secure them before performing the welding step.

10. The process as claimed in Claim 1, further comprising: re -rounding the welded band to restore its cylindrical shape; clipping the edges to remove any remaining flash material; and sanding the welded region to achieve a uniform surface finish.

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