All fibres having a practically unlimited or infinite length are called filaments. Filament fibres are continuous (long) fibre. It may be natural like silk or synthetic like Nylon. Filament fibres measured in yards or meters. Silk, in filament form, is reeled from cocoons. Human-made fibres of chemical composition, liquid nature is forced through spinnerets, hardened and produced into continuous filament strands of a determined length.
When filament fibres cut into staple fibres, large spinnerets with many openings used. The filament fibres grouped into a bundle referred to as tow and then cut into the desired staple length. Line or low human-made fibres manufactured in continuous strands of any desired length. The tows cut into staple lengths or flocks based on specific end-use. See Staple fibre and Microstructure fibre.