Apparatus and method for forming melt-formed inorganic fibres
Apparatus and methods for forming melt-formed fibres and melt-formed biosoluble fibers are disclosed. The apparatus comprises a spinning head comprising one or more rotors; a plurality of nozzles or slots disposed around at least part of the one or more rotors; a conveyor; and a barrier between the spinning head and the conveyor.
1. A mass of melt-formed biosoluble fibres having an overall composition in weight percent of:
SiO 2 : 62-68%;
CaO: 26-32%;
MgO: 3-7%; and
Others: less than 1%,
the melt-formed biosoluble fibres having a length weighted arithmetic mean diameter less than 2 μm and comprising fibres of a length greater than 10 cm, the mass having a shot content of shot having a dimension greater than 45 μm of less than 35 wt %, and capable of being formed by entanglement into a blanket having:
a density of 128 kg·m −3 ;
a thickness of 25 mm; and
a tensile strength greater than 50 kPa from a blanket sample of 230±5 mm×75±2 mm and clamped at each end with an unclamped span of 150±5 mm, wherein the mass of melt-formed biosoluble fibers is a non-deshotted mass of melt-formed biosoluble fibers having a mass of more than 100 grams.
2. The mass of melt-formed biosoluble fibers of claim 1 , the mass having the shot content of shot having a dimension greater than 45 μm of greater than 28 wt %.
3. The mass of melt-formed biosoluble fibers of claim 1 , wherein the length of the melt-formed biosoluble fibres is greater than 20 cm.
4. The mass of melt-formed biosoluble fibers of claim 1 , wherein the length of the melt-formed biosoluble fibres is greater than 30 cm.
5. A mass of melt-formed biosoluble fibres having an overall composition in weight percent of:
SiO 2 : 70-80%;
CaO+MgO: 18-25%; and
Other: less than 3%
the melt-formed biosoluble fibres having a length weighted arithmetic mean diameter less than 2 μm and comprising fibres of a length greater than 10 cm, the mass having a shot content of shot having a dimension greater than 45 μm of less than 35 wt %, and capable of being formed by entanglement into a blanket having:
a density of 128 kg·m −3 ;
a thickness of 25 mm;
a tensile strength greater than 50 kPa from a blanket sample of 230±5 mm×75±2 mm and clamped at each end with an unclamped span of 150±5 mm; and
having a thermal conductivity at 1000° C. of less than or equal to 0.26 W·m −1 ·K −1 ,
wherein the mass of melt-formed biosoluble fibers is a non-deshotted mass of melt-formed biosoluble fibers having a mass of more than 100 grams.
6. The mass of melt-formed biosoluble fibers of claim 5 , the mass having the shot content of shot having a dimension greater than 45 μm of greater than or equal to 33.24 wt %.
7. The mass of melt-formed biosoluble fibers of claim 5 , wherein the length of the melt-formed biosoluble fibres is greater than 20 cm.
8. The mass of melt-formed biosoluble fibers of claim 5 , wherein the length of the melt-formed biosoluble fibres is greater than 30 cm.
9. A mass of melt-formed biosoluble fibres having an overall composition in weight percent of:
SiO 2
73-74.5%;
CaO
22.2-26%;
MgO
0.4-0.8%;
Al 2 O 3
0.9-1.4%;
and
K 2 O
0.5-0.8%,
the melt-formed biosoluble fibres having a length weighted arithmetic mean diameter less than 2 μm and comprising fibres of a length greater than 10 cm, the mass having a shot content of shot having a dimension greater than 45 μm of less than 35 wt %, and capable of being formed by entanglement into a blanket having:
a density of 128 kg·m −3 ;
a thickness of 25 mm;
a tensile strength greater than 50 kPa from a blanket sample of 230±5 mm×75±2 mm and clamped at each end with an unclamped span of 150±5 mm; and
having a thermal conductivity at 1000° C. of less than or equal to 0.26 W·m −1 ·K −1 ,
wherein the mass of melt-formed biosoluble fibers is a non-deshotted mass of melt-formed biosoluble fibers having a mass of more than 100 grams.
10. The mass of melt-formed biosoluble fibers of claim 9 , wherein the length of the melt-formed biosoluble fibres is greater than 20 cm.
11. The mass of melt-formed biosoluble fibers of claim 9 , wherein the length of the melt-formed biosoluble fibres is greater than 30 cm.
12. A blanket of melt-formed biosoluble fibres formed by entanglement of the mass of melt-formed biosoluble fibre as claimed in claim 1 .
13. The blanket of claim 12 having a density in the range 58 to 182 kg·m −3 and having a tensile strength to density ratio of greater than 0.39 kPa/(kg·m −3 ).