The parts work in harmony for selection of hooks
The individual inherently flame retardant fabric manufacturers of harnesses makes it possible to time the shed differently for each weaving cycle if desired.Innovations In Jacquard Shedding SystemsUntil the 1980s, the mechanical jacquard systems were most commonly found in industrial settings and they still exist today in developing countries.
In general, early shed is not desired because of the dragging force of the weft in crossed warp yarns, which causes abrasion and weakening of the warp and weft yarns.When weaving is resumed, the motor initially has to overcome the inertia of the machine’s heavy moving parts, and the machine’s set speed is not reached immediately.
The parts work in harmony for selection of hooks, and hence warp yarns, to be raised or lowered for each shed according to the weave design that is registered on the punch pattern cards. Such settings require mechanical adjustment of the pile harnesses in traditional dobby shedding.
For instance, in weaving fabrics with a mixture of weft yarns — some containing spandex and others without — the shed timing for the former requires early shed to bind these yarns before the beat-up event so they are secured and bound to prevent the spandex yarn from retracting back and causing major fabric defects.