water blocking yarn

Water Blocking Yarn, also known as Water Swellable Yarn, is a high-performance water-blocking material widely used in modern cable manufacturing. It combines high-strength industrial polyester (or nylon) filaments with superabsorbent polymers (SAP) and specialized adhesives. When exposed to water, the yarn rapidly absorbs moisture and expands to form a dense gel that effectively seals cable interstices, preventing longitudinal water penetration along the cable core.