Etex / Siniat Type X Patents: High-Temperature Core Behaviour
Fire-rated boards live or die in the second dehydration. The patent record explains why.
A Type X board passes ASTM E119 not because the core does not dehydrate — it dehydrates twice — but because the second dehydration is delayed and the core retains structural integrity through it. Etex / Siniat patents from the early 2010s describe vermiculite and chopped glass fiber loadings that hold the core together after the chemically bound water has left.
The chemistry is unforgiving. Too little fiber and the core spalls under the second dehydration; too much and slurry rheology breaks. Vermiculite expansion is temperature-history dependent. Run the kiln hot during commissioning and you have already burned half your fire rating before the truck leaves the yard.
We supply chopped E-glass at 13 µm, sized specifically for gypsum slurry interaction. The size chemistry matters: silane-coupled fiber bonds into the dihydrate; unsized fiber rolls in the slurry and creates surface defects on the formed board.