What are the commonly used terms in polyurethane foaming?

Cold cure

1.Cold cure is a foaming process used for seats that produces high resilience (HR) foam.

2.Mold temperature is usually 50–70°C; the polyether molecular weight ranges from 2500 to 6500; ISO can be TDI, TM, or MDI.

3.This process is efficient and energy-saving, and is widely used.

4.Our production uses the cold cure process.

Pump capacity

1.Used to evaluate the stability of metering pump flow output.

2.Current method: set a flow rate, fire 35 continuous shots, weigh each one, calculate capacity, and determine if repair or replacement is needed.

3.Check pump capacity every three months.

Pump linearity

1.Indicates the correlation between pump speed and output.

2.Select 5 speeds, test flow at each, and plot results; a straight line indicates good linearity.

3.Our metering pumps usually achieve over 99% linearity; normal flow should stay within linear output range.

NBT

1.Short for new blending technology.

2.Traditional blending mixes one ISO with one POL; only the ratio and shot weight can be adjusted.

3.NBT mixes one ISO with two or three POLs (requires inverter).

4.Allows adjusting water content, solid content, index, and shot weight—providing more flexibility.

TPR

1.Short for timed pressure release, also known as venting or pre-degassing.

TPR typically starts 90–120 seconds after mold closure, lasting about 2 seconds.

2.Venting too early softens foam and causes tearing; too late causes stiffness and shrinkage after demolding.

Initial shot

1.Normal pouring starts with ISO and POLY nozzles opening at the same time.

2.If not synchronized, unreacted material exits, leading to poor foam.

3.If polyether exits first: sticky raw material appears.

4.If ISO exits first: foam becomes brittle or partially collapsed.

5.In special cases, initial pour areas may feel soft—also due to initial shot timing.

Foam index (Index)

1.Index of 100 means stoichiometric ISO/POL reaction.

2.Index = actual ISO use / theoretical ISO × 100; seat foams typically range from 90–105.

3.Higher index = harder foam.

4.Index >105: foam becomes fragile.

5.Index <85: foam shows closed-cell shrinkage.