Blowroom & Carding
A can is a buffer. Its size sets the doffing labour and whether the drawframe creel starves.
— min
How long one can lasts at this delivery rate
Can capacity uses the full cylindrical working volume; a real can has a spring base or a fixed bottom plate and the sliver does not fill the extreme corners, so measured capacity runs a few per cent below the geometric figure. Packing density should be measured by weighing a full can rather than taken from a catalogue, since it depends on coiler setting and sliver tension as much as on the fibre. The doffing loss assumes the card stops for the change; automatic can changers overlap the change with running and reduce this to near zero, in which case the interval still matters for labour but not for output. Total draft is nominal, and it takes no account of fibre orientation or of the licker-in and flat waste that leave between feed and delivery - use the card production tool for the waste-corrected output.
Card Sliver Draft, Can Capacity & Change Interval — free, with the formula and a worked example, at Textile School.