Polymer & Plastics · Calculate & Specify
Masterbatch Let-Down Ratio (LDR) Calculator
Enter the active content of the masterbatch and the loading you need in the finished part. The calculator returns the let-down ratio, the masterbatch percentage and the resin balance, so a grade change can be dosed correctly on the first batch instead of the third.
LDR-1A
Let-Down Ratio
MMB = ( CFinal / CMB ) × MTotal | MVirgin = MTotal − MMB
kg
%
%
Masterbatch required
20
kg
Virgin polymer backfill
480
kg
Effective LDR
4%
AllZone · Engineering
Use this when
- A customer specifies a TiO₂, pigment or filler level in the part, not in the masterbatch.
- You are switching to a masterbatch with a different active content and need the new dosage.
- You are weighing a mix-bag by hand and need the kg of each component per batch.
How the number is produced
- Masterbatch % = target active in part ÷ active content of the masterbatch.
- Let-down ratio = 100 ÷ masterbatch %, expressed as 1 : N.
- Polymer matrix = 100 % minus every dosed component, so the recipe always closes at 100 %.
Materials for this job
- Masterbatch — white, colour, additive, desiccantThe grades you dose against the ratio this tool returns.
- Mineral fillers, pigments & reinforcementCalcium carbonate, talc and TiO₂ in powder and masterbatch form.
- Polymer & plastics raw materialsResins, fillers, masterbatch and additives in one catalogue.
Engineering aid only. Validate against your own instrumented trial, the polymer datasheet and the applicable ASTM / ISO method before locking a process window or a specification.
Related knowledge & tools
- White masterbatch vs direct titanium dioxideDecide what the active content in your dosage actually is.
- Carrier selection for colour masterbatchWhy the same ratio behaves differently on another carrier.
- Mineral powder or filler masterbatchChoose the dosing form before you fix the ratio.
- All Polymer & Plastics toolsCalculate, diagnose and specify in one place.
- Polymer & Plastics KnowledgeSolve a problem, choose and compare, learn, calculate.
- Production & formulation engineering matrixThe full shop-floor suite, including SEC and screen-pack ΔP.
- Allzone Knowledge CenterSearch by problem, industry or material.