Filamentkiud

Filamentkiud, or filament fibers, are long, continuous fibers with a high length-to-diameter ratio. They can be natural, such as silk filaments produced by silkworms, or synthetic, formed by extrusion of polymers like polyester or nylon. Filament fibers may be monofilament (a single continuous filament) or multifilament (a bundle of many filaments). A further distinction is filaments in tow, which is a loose bundle used to produce staple fibers by cutting.

Manufacturing methods depend on the polymer. Thermoplastic polymers are typically produced by melt-spinning, where molten polymer is forced through a spinneret and solidified. Solutions can be used in dry spinning or wet spinning for polymers that do not melt cleanly. Natural silk filaments are spun by the silkworm and harvested as continuous threads. Multifilament yarns can be further drawn, twisted, or textured to adjust strength, elasticity, and handle.

Filament fibers have distinctive properties. They generally offer high tensile strength and modulus per cross-section, a smooth surface, and good luster. They tend to have low or moderate moisture regain depending on the material and can be highly durable. Their performance is influenced by drawing, finishing, and any surface treatments. Some filaments are heat- or chemical-sensitive, requiring appropriate processing conditions.

Applications of filamentkiud include high-sheen fabrics such as satin and tulle, technical textiles and composites where reinforcement is needed, fishing lines and sewing threads, and cordage. They are often used alone or as components in blends with staple fibers to balance texture, warmth, and performance.