TIG Welding, Plasma Welding, Or Laser Welding for Washing Machine Inner Drums?

Among the core components of a washing machine, the welding quality of the inner drum directly affects the equipment's stability, service life, and operational noise. As a key process for connecting various parts of the inner drum, the selection of welding technology must balance multiple factors such as efficiency, precision, and cost. Currently, the mainstream technologies in the field of washing machine inner drum welding include TIG welding, plasma welding, and laser welding. Each has unique characteristics and significantly different application scenarios. This article will detailedly analyze the principles, advantages, disadvantages, and industry application status of these three technologies.

I. TIG Welding: A Cost-Effective and Efficient Basic Choice

TIG (Tungsten Inert Gas) welding is a welding technology developed based on the principle of ordinary arc welding. Its core lies in using argon gas to protect the metal welding material. A high current melts the welding material on the base material to form a molten pool, achieving a metallurgical bond between the welded metal and the welding material. During the welding process, argon gas continuously sprays from the nozzle, isolating the molten pool from air oxidation and ensuring welding quality.

Technical Characteristics and Application Scenarios

The prominent advantage of TIG welding lies in the balance between efficiency and cost. By matching the current with the torch moving speed, its welding speed can reach up to 4500mm/min, meeting medium to high production capacity requirements. Meanwhile, compared with the other two welding methods, the total investment in TIG welding equipment is the lowest, making it particularly suitable for cost-sensitive production lines.

However, this technology has obvious limitations: the heat-affected zone  during welding is relatively large, resulting in high deformation and residual stress of the welded joint, which may affect the roundness and operational stability of the inner drum. In addition, welding spatter and slag adhesion are prone to occur during the process, and tungsten electrode wear can flatten the electrode tip, increasing the difficulty of arc striking. Regular grinding or replacement of the tungsten electrode is required (maintenance is needed after approximately every 150 welded products), leading to a relatively high maintenance frequency.

In practical applications, due to its low-cost，TIG welding is widely used in the production of economical washing machine inner drums where deformation requirements are not strict. Some production lines of enterprises such as Qingdao Hisense and Haier adopt this technology.

II. Plasma Welding: A Mid-Range Choice with Balanced Performance

Plasma welding uses a plasma arc as the heat source. The arc heats and dissociates gas, which is compressed when passing through a water-cooled nozzle at high speed to form a plasma arc with higher energy density and dissociation degree, achieving precise fusion of materials.

Technical Characteristics and Application Scenarios

The core advantages of plasma welding lie in arc stability and penetration. Its plasma arc is cylindrical with a diffusion angle of only about 5 degrees. Even if the arc length fluctuates, the heating area of the base material does not change significantly, and it is less sensitive to changes in working distance. Meanwhile, by optimizing process parameters, welds with uniform root penetration and smooth, neat surfaces can be achieved, with welding quality superior to TIG welding.

However, this technology has higher requirements for incoming material quality: it requires better surface cleanliness and fewer burrs on inner drum components, and higher precision control of equipment splicing gaps. In terms of maintenance, although the tungsten electrode wear cycle is longer (maintenance is needed after approximately every 1500 products), the copper nozzle is prone to wear due to spatter and slag, requiring regular replacement.

With balanced performance, plasma welding is suitable for production lines that have certain requirements for welding quality but have a budget lower than that for laser welding. Enterprises such as Hefei Meiling, Whirlpool have successfully applied this technology in the production of washing machine inner drums, improving product reliability while ensuring cost-effectiveness.

III. Laser Welding: A High-End Solution with High Precision and Low Deformation

Laser welding uses a focused high-energy laser beam as the heat source to achieve precise welding through the heat generated by bombarding the welded parts, making it one of the most precise welding technologies currently available.

Technical Characteristics and Application Scenarios

The biggest highlight of laser welding is "high efficiency + precision". Its welding speed can reach up to 5000mm/min, ranking first among the three technologies. More importantly, the laser beam energy is concentrated, which can minimize the heat input, resulting in an extremely small range of metallographic changes in the heat-affected zone and minimal deformation caused by heat conduction. This can maximize the dimensional accuracy and structural stability of the inner drum, with the optimal weld smoothness.

However, the shortcomings of this technology lie in cost and thresholds: the one-time investment in equipment is significantly higher than that of TIG and plasma welding, and additional cleaning equipment needs to be configured to meet the surface cleanliness requirements of incoming materials. Meanwhile, the control precision requirements for component splicing gaps are higher than those for plasma welding, posing greater challenges to the overall process level of the production line.

Laser welding is suitable for the production of high-end washing machine inner drums, especially products with strict requirements for operational noise and service life. Enterprises such as Gree have applied it in actual production, improving the core competitiveness of products through high-precision welding.

IV. Result comparison of these 3 welding methods

TIG welding

Plasma welding

Laser welding

V. Technical Comparison and Industry Development Trends

The core differences between the three welding technologies can be summarized as follows: In terms of efficiency, laser welding (5000mm/min) is slightly higher than TIG welding (4500mm/min), with plasma welding in the middle. In terms of precision and deformation, laser welding has the smallest heat-affected zone (approximately 1.5mm) and the lowest deformation, while TIG welding has the largest heat-affected zone (approximately 4.5mm) and the most significant deformation. In terms of cost, TIG welding has the lowest equipment investment, and laser welding has the highest. In terms of maintenance frequency, TIG welding requires the most frequent electrode grinding, followed by plasma welding, and laser welding has relatively low maintenance needs.

In industry applications, enterprises usually select technologies based on product positioning, production capacity requirements, and cost budgets: economical production lines prefer TIG welding, mid-range products tend to use plasma welding, and high-end models mostly adopt laser welding. With the improvement of consumers' requirements for washing machine performance and the development of automation technology, the application proportion of high-precision technologies such as laser welding is gradually expanding.

Wuxi IDO Technology, by focusing on technological innovation in thin sheet metal precision stamping, welding, and forming, have developed fully automatic inner drum welding production lines (covering laser, plasma, and TIG), promoting the development of washing machine inner drum welding towards "more precise, more efficient, and more automated" directions, and providing strong support for industry technological upgrading. In conclusion, the selection of welding technology for washing machine inner drums needs to comprehensively consider multiple factors, and the continuous innovation and application of technologies will continuously drive the washing machine industry towards higher quality.