Packs per roll: account for repeat length, lanes and waste

The purchasing question

Roll length alone does not determine pack count. Each machine repeat advances a length of web and may produce several packs across it. The approved production layout, rather than a finished pouch dimension chosen by intuition, determines repeat and lane count.

Calculation method

Theoretical complete repeats = floor(usable roll length ÷ repeat length). Multiply complete repeats by packs produced per repeat. With a waste rate on gross input, first estimate usable length from the gross reel length and then count complete repeats. Include startup and known splice losses on a consistent basis.

Worked example

A 5,000 m reel and a 250 mm repeat provide 20,000 complete nominal repeats. With two packs per repeat, nominal output is 40,000 packs. An illustrative 4% gross-length loss leaves 4,800 m and 38,400 packs. At a reel price of €768, material cost is €20 per thousand accepted packs.

This is a material-yield estimate, not a machine-speed prediction. Lane changes, registration issues and actual rejected units may change output. Reconcile the planned count with reel consumption and accepted-pack records after the run.

Checks before using the result

• Enter repeat length in the selected unit.
• Count packs per machine repeat, including all approved lanes.
• Do not count a fractional final repeat as a finished pack.

Common questions