Cutting wire market has broad application prospects

As a clean and inexhaustible energy source, solar power has gained increasing attention across industries. Solar cells are primarily made from non-toxic crystalline silicon, with monocrystalline and polycrystalline silicon cells being known for their high efficiency, long lifespan, and stability. However, the cost of these materials remains relatively high. With advancements in semiconductor manufacturing technology, the cost of silicon wafers has gradually decreased. Yet, the cost of cutting silicon wafers—essential for producing solar cells—still accounts for over 30% of the total production cost. This makes cutting wires and steel wire rods key components in the photovoltaic supply chain.

In China, the development of cutting steel wire is still in its early stages. Despite challenges such as economic pressures and industry competition, the photovoltaic sector is undergoing restructuring. As the industry stabilizes, there's hope that China will see significant growth in its "spring" cutting wire and wire rod sectors. Improvements in wire rod quality suggest that domestic products may soon replace imported ones in the photovoltaic industry.

Cutting wires have promising applications, especially in the global solar PV industry. China is a major producer of photovoltaic modules, and crystal silicon cutting is a critical process in this supply chain. According to data, 1 MW of crystalline silicon solar panels requires about 12 tons of silicon, and each ton needs 0.7 tons of cutting wire. Given the high cost of silicon wafers (around $60/kg), precision in the cutting process is essential. The wire diameter, speed, and cutting area must be carefully controlled to ensure uniform thickness and prevent breakage during slicing. As a result, cutting wires must meet strict specifications, typically ranging from 0.07mm to 0.2mm, with high tensile and fatigue strength.

Bekaert was one of the first companies to enter the cutting wire market, once holding a monopoly. In China, several companies are now involved in this field, including Zhenjiang Resistance Wire and Changzhou Fandeng, which have expanded into cutting steel wire production. (For more details on domestic manufacturers, please refer to the attached table.)

The production of cutting wires is complex and has a low yield rate. Additionally, there are strict compensation rules between wire manufacturers and silicon wafer producers. If a wire breaks during slicing, the manufacturer not only compensates for the lost wire but also covers damages caused by broken wafers. This adds to the overall cost, with prices ranging from 9 to 12 yuan per meter, or approximately 10 yuan per ton.

Cutting wires come in two main types: copper-plated and diamond-coated. Copper-plated wires are cost-effective but require frequent replacement due to lower efficiency and higher fluid consumption. Diamond-coated wires, on the other hand, offer better efficiency, reusability, and no need for cutting fluids, though they are more expensive. While diamond wires are popular in Japan, they are still emerging in the Chinese market.

With strong market demand and high profitability, the quality of cutting wire rods is under pressure to improve. Although many Chinese steel mills have developed cutting wire rods, there is still a gap compared to imported alternatives. High-carbon wire rods with 0.85-0.9% carbon content are commonly used, similar to those for cords. However, since cutting wires are used as single filaments rather than in bundles, stricter requirements apply regarding inclusion, stripe structure, and crystal organization. Only a few global manufacturers, such as Sasset, Nippon Steel, and Kobe Steel, can consistently produce high-quality cutting wire rods.

Several Chinese steel companies, including Baosteel, Wuhan Iron & Steel, and Anshan Steel, are now developing cutting wire rods. Some have even established dedicated production lines for cutting steel wire. Baosteel’s wire rods have been tested in pilot batches, showing potential for future use.

Japanese manufacturers employ meticulous control over raw materials, additives, and production processes. While Chinese steel mills follow similar guidelines, implementation often falls short. This is an area where domestic companies need to focus on improvement.

Despite challenges, opportunities remain. The Chinese government continues to support clean energy, with policies like the “Twelfth Five-Year Plan” promoting solar energy. The introduction of grid-connected tariffs in 2011 marked a milestone for domestic solar adoption. As processing costs decrease and the industry becomes more standardized, the cost of solar power generation is expected to drop, paving the way for broader adoption in China.