Blow Molding & Hollow Plastic Products worked example

Bottle Weight Variation with nominal bottle weight of 130 g: a worked example in blow molding & hollow plastic products

This scenario runs the bottle weight variation calculation on the strong side: nominal bottle weight of 130 g, with every other input held at its documented default. a blow molding team needs to quantify how measured bottle weight variation scales across a run or sample

The inputs for this scenario

  • Nominal bottle weight: 130 g (raised for this scenario; the documented default is 52)
  • Measured weight variation share: 0.04 fraction (unchanged)
  • Bottles represented (production run): 10,000 bottles (unchanged)
  • Unit conversion multiplier: 1 x (unchanged)

Working through the calculation

  • Applying the documented formula (Bottle weight variation per represented unit = nominal bottle weight × measured weight variation share) to the inputs above produces each figure below.
  • At this operating point the engine returns 45,500 g or lb for total bottle weight variation exposure, the number this scenario is built around.
  • At this operating point the engine returns 45,500 g or lb for weight variation before conversion.
  • At this operating point the engine returns 1 x for unit conversion multiplier.
  • At this operating point the engine returns 4.55 g or lb for bottle weight variation per represented unit.

How this compares with the baseline

  • Against the tool's baseline example, where nominal bottle weight sits at 52 g and the headline result is 18,200 g or lb, this scenario comes in 150% above the baseline at 45,500 g or lb.
  • Use it when validating a new parison program, qualifying a regrind blend, or quantifying the resin cost of letting weight tolerance widen on a long production run. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Total bottle weight variation exposure: 45,500 g or lb (headline result)
  • Weight variation before conversion: 45,500 g or lb
  • Unit conversion multiplier: 1 x
  • Bottle weight variation per represented unit: 4.55 g or lb

Run it with your numbers

  • Every input above is editable in the live Bottle Weight Variation calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.