EuroWire July 2022

Technical Article

• Estane ZHF 90AT8H NAT 02 • Estane ZHF 90AM9 NAT 01 • Estane ZHF 95AP7 NAT 01

Time to Peak Heat Release (second)

3.3.2 Results Compared to other Estane HNHFR grades, Estane ZHF 90AM9 NAT 01 shows improved cone calorimetry properties like THR, PHR and MARHE (see Graphs 1 to 3 ), which contributes to its excellent cable flame test performance. This new grade is only surpassed by Estane ZHF 95AP7 NAT 01, the highest halogen-free flame-retardant TPU in the market, which complies with cable bundle flame tests. The lower the heat release rate and peak heat release, the slower combustion of surrounding materials in case of fire, and thus reduction of the flame spread throughout and increasing escape time. Estane ZHF 90AM9 NAT 01 shows evidence of a good solid crust formation, which is apparent when looking at its mass loss rate ( Graph 5 ), which is second best after Estane ZHF 95AP7 NAT 01. In Graphs 1 to 5 you can see peak heat release (PHR), total heat release (THR), maximum average rate of heat release (MARHE), time to PHR and total mass loss rate (TMLR) of several NHFR Estane grades vs Estane ZHF 90AM9 NAT 01. Figures 1 to 4 represent type of char formation of Estane NHFR grades, with Estane ZHF 90AM9 NAT 01 among others, after cone calorimetry testing.

Estane® ZHF 58202 NAT 02

Estane® ZHF 90AT8H NAT 02

Estane® ZHF 90AM9 NAT 02

Estane® ZHF 95AP7 NAT 01

Estane® ZHF 90AT2 NAT 055

Graph 4 : Time to peak heat release comparison

Total Mass Loss Rate (G/m 2 )

Estane® ZHF 58202 NAT 02

Estane® ZHF 90AT8H NAT 02

Estane® ZHF 90AM9 NAT 02

Estane® ZHF 95AP7 NAT 01

Estane® ZHF 90AT2 NAT 055

Graph 5 : Total mass loss rate comparison

Peak Heat Release PHR (kW/m 2 )

Figure 1 : Estane ZHF 90AT8H NAT 02

Figure 2 : Estane ZHF 90AT2 NAT 055

Peak Heat Release Rate PHRe

Estane® ZHF 58202 NAT 02

Estane® ZHF 90AT8H NAT 02

Estane® ZHF 90AM9 NAT 02

Estane® ZHF 95AP7 NAT 01

Estane® ZHF 90AT2 NAT 055

Graph 1 : Peak heat release comparison

Total Heat Release THR (MJ/m 2 )

Figure 3 : Estane ZHF 90AM9 NAT 01

Figure 4 : Estane ZHF 95AP7 NAT 01

3.4 UL heat and ISO 6277 hydrolytic stability, and VDE 282 accelerated ageing testing Estane ZHF 90AM9 NAT 01 is UL 105°C and VDE 282 compliant. Also, after the stringent automotive hot humidity test – according to ISO 6722 – good property retention is achieved indicating excellent hydrolytic stability of the compound, as can be observed in the following tests performed (all ageing tests were performed on 1mm extruded strips). 3.4.1 UL 105°C ageing test Table 4 summarises the outcome of the tests. The following requirements need to be met to qualify for UL 105°C temperature rating.

Estane® ZHF 58202 NAT 02

Estane® ZHF 90AT8H NAT 02

Estane® ZHF 90AM9 NAT 02

Estane® ZHF 95AP7 NAT 01

Estane® ZHF 90AT2 NAT 055

Graph 2 : Total heat release comparison

Maximum Average Rate of Heat Release (kW/m 2 )

Initial mechanical values: • Minimum tensile strength: 17.2 MPa • Minimum elongation: 450 per cent

After 168 hours heat ageing @ 136°C: • Minimum tensile strength: 35 per cent of initial value • Minimum elongation: 85 per cent of initial value

Estane® ZHF 58202 NAT 02

Estane® ZHF 90AT8H NAT 02

Estane® ZHF 95AP7 NAT 01

Estane® ZHF 90AT2 NAT 055

Estane® ZHF 90AM9 NAT 02

Graph 3 : MARHE comparison

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July 2022