Structure and Material of Spinnerets for Wet Spinning and Their Performance

On a chemical fiber production line, the spinneret performs the most critical transformation: turning liquid into fiber. In essence, it is a precision-machined nozzle that extrudes a metered amount of spinning solution or melt through extremely fine holes. These tiny streams then pass through cooling air or a coagulation bath, where they solidify into the filament fibers we ultimately see.

To maintain stable production, a spinneret rarely works alone. It is typically assembled together with components such as distribution plates and filter media. The precision of the spinneret itself directly determines the quality of the finished filaments and is closely tied to a plant’s operating costs.

Different spinning methods require very different spinneret designs. In industry, they are generally divided into three main categories.

Melt spinning spinnerets are usually designed as circular plates, often referred to as spinneret plates. Because melt spinning processes high-temperature polymers, these plates are commonly made from heat-resistant stainless steel. Their structure is relatively simple, which makes both machining and maintenance comparatively convenient.

Wet and dry spinning spinnerets, by contrast, face far more demanding conditions. Wet spinning in particular involves complex chemical solvents, so the spinneret must offer exceptional corrosion resistance and extremely high machining precision. As a result, the manufacturing difficulty is significantly higher.

For many years, wet spinning spinnerets relied on gold-platinum alloys to ensure stability in highly corrosive environments. Although these precious metals offer excellent performance, their extremely high cost has pushed the industry to search for more economical alternatives.

Tantalum, a rare metal, has emerged as one of the main competitors to gold-platinum alloys thanks to its strong chemical stability and good machinability. It is significantly less expensive and also performs well in terms of electrical conductivity and corrosion resistance.

Despite its potential, tantalum’s relatively low hardness limits its large-scale adoption. Pure tantalum typically has a hardness of only about 100–120 HV. Under prolonged high-pressure operation, this can allow the spinneret holes to undergo slight deformation.

In real production environments, this material limitation can trigger a chain reaction. After a period of use, the frequency of spinneret hole blockage tends to increase, while filament defects and off-grade products also rise. Because these issues often lead to more frequent, unplanned spinneret replacements, many factories still remain cautious when adopting tantalum spinnerets.

Understanding these material characteristics and structural differences is fundamental to optimizing spinning processes and balancing product quality with production cost.