Knitting Utilities
The motor is a third of the load. The suction and the air are the rest.
— kWh/kg
Total electrical load divided by net production
Power inputs should be measured load rather than nameplate rating; motors on circular knitting machines typically run well below rating and using the plate overstates the total by twenty per cent or more. The calculation treats load as constant while running and counts no standby consumption during stops, so a machine with poor availability will show a better specific energy here than it achieves in practice. Compressed air is converted at a specific generation figure that assumes a reasonably maintained 7 bar system; a leaky or badly controlled system is substantially worse and the figure should be taken from the compressor house rather than assumed. Auxiliary services shared between several machines - central suction, hall humidification, lighting - must be apportioned before they are entered, and hall air conditioning is excluded entirely although on a humidity-controlled floor it can rival the machines' own consumption. Production is derived from knitting geometry at the greige state, before any finishing weight change.
Circular Knitting Specific Energy, Cost per Kilogram & Carbon — free, with the formula and a worked example, at Textile School.