Recycled Filament Blend Calculator

What this tool calculates

Turn a target spool batch into weighed recycled polymer, virgin polymer, and additive amounts before the hopper is loaded.

Formula and method

Required input = target usable mass ÷ (1 − process loss). Additive = required input × additive share. Polymer input is the remainder; recycled polymer = polymer input × recycled share; virgin polymer is the balance.

When to use it

Use this when weighing a repeatable test batch from clean, correctly identified regrind plus compatible virgin polymer and a supplier-specified masterbatch or additive.

Worked example

For 1 kg of usable filament, 40% recycled polymer, 2% additive, and 8% expected loss, load about 1.087 kg total: 0.426 kg recycled polymer, 0.639 kg virgin polymer, and 0.022 kg additive.

Assumptions and limitations

All percentages are by mass. Recycled and virgin streams are compatible grades, and the entered loss is your measured planning assumption. The calculator does not decide polymer compatibility, safe additive loading, drying conditions, or mechanical-property retention. Follow material and equipment documentation.

Common mistake

Do not treat an additive percentage as part of the recycled/virgin polymer ratio; this tool separates the additive from the polymer portion.