The yarn to be used on warp knitting machines is wound on cylindrical elements, called warp beams, provided with two lateral flanges.

The preparation of warp beams (i.e. warping) is performed upstream to the knitting stage (picture 125). A

Picture 125 - Layout of a direct warping system

The single threads are unwound from packages or cops placed on a creel (A), and then conveyed through a reed (B) while special eyelets keep them separated. Thereafter, they pass through two toothed reeds (C) monitored by a photoelectric instrument (D) that detects the presence of broken filaments or detached fibres.

The system also incorporates an oiling system (E) and a buffer device (F) for the yarn which stores the warp when the beam is counter-rotated to find a broken filament.

The threads pass through a ionising apparatus (G) which eliminates electrostatic charges, then through a reduction reed (H). Finally, the warp threads are wound on the warp beam (L): in this last stage, the threads run very close to one another in overlapping layers of uniform density and tension prior to being wound onto the beam.

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