Question 1

What is an isocyanate index calculator?

Accepted Answer

An isocyanate index calculator calculates the required isocyanate quantity needed to reach a target NCO index in a polyurethane foam formulation.

Question 2

What does an NCO index of 100 mean?

Accepted Answer

An NCO index of 100 means the isocyanate equivalents are theoretically balanced with the reactive hydrogen equivalents from polyols, water and other active hydrogen components.

Question 3

Can this NCO index calculator be used for TDI and MDI?

Accepted Answer

Yes. The calculator uses the entered NCO percentage to calculate isocyanate equivalent weight, so it can be used for common TDI, MDI and p-MDI grades when the correct %NCO value is entered.

Question 4

Why is water included in the PU foam isocyanate calculation?

Accepted Answer

Water reacts with isocyanate and consumes NCO groups while producing carbon dioxide for chemical blowing, so water must be included in polyurethane foam index calculations.

Question 5

When should I use the TDI calculator instead?

Accepted Answer

Use the dedicated TDI calculator when the calculation is only for TDI-based flexible polyurethane foam. Use this isocyanate index calculator for broader NCO index calculations covering TDI, MDI, p-MDI or custom isocyanate %NCO values.

Isocyanate Index Calculator

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