EuroWire May 2018

Technical Article

Fire performance results with Sepiolite Masterbatch Thanks to the structural properties of Sepiolite, homogeneous dispersion and easy incorporation of the Masterbatch, a much stronger and more consistent char layer in the compound under fire (see Figure 6 ) can be found. To prove this, two standard Masterbatches with different common polymers have been tested under fire. HFFR compound with ATH and Delta Master EV-00168 with 40 per cent Adins Clay and 60 per cent EVA Table 1 shows a standard EVA-based HFFR formulation (left column), compared with

one adding the Sepiolite Masterbatch whilst reducing both EVA and some ATH (right column). The result of the cone calorimeter tests at 50 kw/m 2 of radiation and at 25mm of distance demonstrates a drop in the peak heat release rate, a reduction in the area and a delay and reduction in the second peak (see Figure 7 ). HFFR compound with natural MDH and Delta Master EV-00168 with 40 per cent Adins Clay and 60 per cent EVA Table 2 shows a standard EVA-based HFFR compound with natural milled MDH, compared with one that adds the Sepiolite Masterbatch whilst reducing both EVA and some MDH.

When applying the cone calorimeter tests, there is again a significant reduction in the maximum of heat release rate along with a notable delay in the peak, a significant improvement attributable to the synergist effect (see Figure 8 ). PVC flame-retardant with ATO and Delta Master EV-00167 with 30 per cent Adins Clay In this case, one common PVC formulation with ATO is compared with one in which the ATO content has been removed and substituted with a standard Sepiolite Masterbatch (see Table 3 ). What this comparison intends to prove is that the Sepiolite Masterbatch offers a suitable substitute to ATO, providing similar results in terms of both smoke density and heat release (see Figure 9 ).

▼ ▼ Figure 7 : Sepiolite behaviour in standard ATH compound

▼ ▼ Figure 8 : Sepiolite behaviour in standard MDH compound

▼ ▼ Figure 9-1 : Sepiolite behaviour in standard ATO PVC compound. Smoke density

▼ ▼ Figure 9-2 : Sepiolite behaviour in standard ATO PVC compound. HRR

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May 2018