Special Glasses

SPECIAL GLASSES

 

P808 (BLUE)

P808 glass combines the features of the 608 (former poly glass) and the 808.
P808 is characterised by an extremely low surface roughness and by excellent non-stick properties. The extreme smoothness of its surface is better than what can be achieved with any other type of glass or mirror-polished metal.

Its use is recommended for polymerization reactors where the problem of the formation of deposits and incrustation is frequently encountered on the walls of the vessel and its internal components or accessories. Glasses, by their very nature, have surfaces that are chemically inert, electrically saturated and hence have little tendency to form bonds with the polymer.

In the P808 glass, these non-stick and repulsion properties of the surface have been further enhanced.

Polymerizers lined with P808 are well-known for their high rates of production and for the assurance of an unvarying quality of polymer. Freedom from sticking of the polymer permits heat exchange performance and production cycle times to be maintained constant. A Shut-down for cleaning is eliminated or drastically reduced.

A surface roughness Ra of 0.03 µm maximum is guaranteed for reactors of even large capacity.

DURAVIT 258; DURAVIT 259; DURAVIT 255

Duravit 258 (blue), Duravit 259 (white) Duravit 255 (light blue) are particularly suited for coating agitators, baffles, thermowells, protection rings and all the small accessories that are generally mounted on glass-lined reactors using 808, 809 and 805 for their lining.

Duravit 258, ..9 and ..5 are vitreous glasses with a high chemical resistance with suitably balanced pre-stressing to provide a higher resistance to chipping or spalling at convex surfaces with small radii.

The compression strength of a glass coating is considerably higher than its tensile strength. For this reason, the composition of a glass coating is formulated in a way that after application the layer of glass is pre-stressed.

This gives rise to a resultant force, radial to the surface, that becomes greater as the radius of curvature becomes smaller. At concave surfaces, the force makes the coating adhere better to the underlying steel base. At convex surfaces, on the other hand, the coating tends to become detached. The balanced pre-stressing of Duravit 258, 259 and 255 reduces the radial component and prevents chipping or spalling even on very convex surfaces.