Dyneema line (Dyneema is a registered trademark of Dutch company DSM, with the generic name ultra-high molecular weight polyethylene fiber, abbreviated as UHMWPE) is one of the strongest fiber materials known to mankind. Its specific strength is 15 times that of steel wire, 8 times that of ordinary nylon, and 1.5 times that of aramid fiber (Kevlar), while its density is only 0.97g/cm³ (lighter than water), making it the preferred material for high-end fishing line and industrial safety ropes. Dyneema fiber used for braiding is typically divided into three grades: SK65 (standard grade, strength about 32cN/dtex, modulus about 950cN/dtex, suitable for ordinary fishing line), SK75 (high-performance grade, strength about 36cN/dtex, modulus about 1160cN/dtex, suitable for high-strength fishing line and light industrial ropes), and SK99 (ultra-high performance grade, strength about 42cN/dtex, modulus about 1580cN/dtex, suitable for deep-sea fishing and aerospace applications). The price differences between different grades are substantial—SK65 is about 80-120 yuan/kg, SK75 is about 150-220 yuan/kg, and SK99 is about 400-600 yuan/kg. Enterprises need to make reasonable trade-offs based on the positioning of end products when selecting materials.