How much does a stretch film rewinding machine produce?

Monthly capacity at a glance

Theoretical gross output per month on one 8-hour shift a day, with the roll length that gives each machine its highest output:

How the figures are calculated

• Working time: one 8-hour shift a day, 22 or 26 working days a month.
• Speed: the speed shown for each machine in the tables below.
• Cycle time: the time to wind one roll plus the machine's automatic roll change.
• Jumbo rolls: 6,000 m each (12,000 m on the SP-1400), with one minute per jumbo roll change.
• Roll weights (gross, including the core):
• 200 m roll: 2 kg (core 0.4 kg)
• 1500 m roll: 16.5 kg (core 1.5 kg)
• SP-1400, 600 m pre-stretched roll: 2.1 kg (core 0.36 kg); 4000 m roll: 13.1 kg (core 1.5 kg, calculated)
• CR-1700, coreless roll of about 1300 m: 14 kg, all of it film (length estimated)

Hourly output

Excluding jumbo roll changes:

Monthly output by roll length

Including jumbo roll changes, one 8-hour shift a day:

The figures are for one machine; each SR-1500 or SM-1300 L produces the amounts shown.

What changes the real figure

The tables are averages calculated under fixed assumptions. In a real plant, output can be noticeably higher or lower:

• Shifts and working hours: the figures are for one 8-hour shift. In theory, two shifts double the output and three shifts triple it.
• Working days: 22 or 26 days a month, minus holidays and planned shutdowns.
• Running speed: the calculation uses top speed. Very thin, soft or very clingy films, or jumbo rolls of uneven quality, often have to run slower.
• Roll length: every roll needs a change cycle, so short rolls spend a larger share of the time changing: the SM-1300 2S PRO produces about 503 kg an hour with 200 m rolls but about 901 kg with 1500 m rolls.
• Film thickness and width: tonnes depend on the weight of each metre. Thicker or wider film gives more tonnes for the same metres; pre-stretched film is very thin, which is why the SP-1400 produces many metres but fewer tonnes. See roll length and weight.
• Jumbo rolls: the calculation assumes 6,000 m jumbo rolls and a one-minute change; shorter jumbo rolls or slower changes reduce output.
• Stoppages: breakdowns, maintenance, cleaning, film breaks, breaks, loading cores and packing finished rolls are not included.
• Product changes: switching roll length, width, core or film type, or setting up slitting, takes time.
• Operator experience: a trained operator keeps the machine running with fewer and shorter stops.
• Cores: gross weights include the paper core (1.5 kg of a 16.5 kg roll of 1500 m); the CR-1700's coreless rolls are all film.