Blow Molding & Hollow Plastic Products worked example

Parison Weight with programmed parison weight per cavity of 160 g: a worked example

This scenario runs the parison weight calculation on the strong side: programmed parison weight per cavity of 160 g, with every other input held at its documented default. an extrusion blow molding line needs to check parison resin charge for a bottle, container, duct, reservoir, or hollow part before running

The inputs for this scenario

  • Programmed parison weight per cavity: 160 g (raised for this scenario; the documented default is 62)
  • Active mold cavities: 4 cavities (unchanged)
  • Flash and trim allowance multiplier: 1.12 x (unchanged)
  • Unit conversion multiplier: 1 x (unchanged)

Working through the calculation

  • Applying the documented formula (Parison weight across active cavities = programmed parison weight per cavity × active mold cavities) to the inputs above produces each figure below.
  • At this operating point the engine returns 717 g or lb for total parison resin charge, the number this scenario is built around.
  • At this operating point the engine returns 717 g or lb for parison charge before conversion.
  • At this operating point the engine returns 1 x for unit conversion multiplier.
  • At this operating point the engine returns 640 g or lb for parison weight across active cavities.

How this compares with the baseline

  • Against the tool's baseline example, where programmed parison weight per cavity sits at 62 g and the headline result is 278 g or lb, this scenario comes in 158% above the baseline at 717 g or lb.
  • Use it when commissioning a new mold, validating a part weight against a print, or estimating resin draw for quoting and material ordering. 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 parison resin charge: 717 g or lb (headline result)
  • Parison charge before conversion: 717 g or lb
  • Unit conversion multiplier: 1 x
  • Parison weight across active cavities: 640 g or lb

Run it with your numbers

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

Last reviewed 2026-05-12.