SPECIALIZATION OF VALMIERA HIGH SILICA GLASS FIBRE FABRIC
SPECIALIZATION OF VALMIERA HIGH SILICA GLASS FIBRE FABRIC:
- The characteristics of High Silica fabric are defined by the Low Smoke Emission,
High Melting Point, Drapability, Water repellence, versatility and fireproof.
- Valmiera uses a special E- Glass fabric with over 76% Silica & Aluminum Oxide (Al2O3) - 3.5 +/-
0.5% in it for the production of High Silica fabric. A soft acid is used to leach the fabric. The
leeching is also done to obtain just about 95-96% Silica content in the fabric.
- Most other manufacturers use a normal E - Glass fabric with about 55% Silica content and
leach it using a strong acid like Hydrochloric Acid ( HCl) to obtain a 98%+ Silica rich fabric. This
strong acid attack weakens the fabric, thereby reducing the tensile strength to a large extent.
A microscopic study of the silica fibre strand also shows a very rough surface after the acid
action on the yarn surface. A very high temperature resistance is also not possible and fabric
is seen to be brittle to a large extent.
- The Aluminum Oxide has higher melting temperature 660º C and is a very soft and
ductile metal. This enhances the temperature resistance of the fabric itself and also
renders the fabric very soft (absolutely non brittle). The temperature resistance of
Valmeira’s High Silica fabric is therefore 1100º C minimum.
- The soft acid leaching results in high tensile strength of the Valmiera's High Silica fabric.
The value of the tensile strength is almost double higher to compare with the
conventional 99% silica fabric.
- The other major advantage is the low shrinkage factor of just about 1.5% with
Valmiera's High Silica fabric compared to the shrinkage of standard of Silica Fabric
which is not less than 7%.
- The Combination of silica (SiO2) and Aluminum acid (Al2O3) has rendered the fabric more