Announcement was made
at Lafayette, Indiana in 1927 of physical and chemical processes by which
natural materials of the earth could be reconstituted into true, homogenous
stone. After first introducing this new material, "ROSTONE", in the
building field in the early 1930's, applications were developed for its use
in electrical insulation moldings. These moldings, characterized by the
inherent heat resistance and dimensional stability of the synthetic stone
reaction, were given the name, "ROSITE". In 1937 Rosite entered the field
as a new kind of arc-proof, non-carbonizing material which could be molded
accurately to complex shapes.
completely inorganic compositions, basically inert and inflammable, other
specialized organic and inorganic bonded materials have been added to the
Rosite line. Certain of these materials provide actual "arc-quenching" and
improved interruptive capacity. Through this capability and the minimizing
of required clearances for protection against tracking, physical reduction
in size for a number of electrical devices has been accomplished.
For more than twenty
years, Rostone Corporation has continued in the development of Rosite and
has specialized in the manufacture of custom moldings of the material for
high temperature applications and for those requiring freedom from tracking
when exposed to high intensity arcs or arc promoting conditions.
Rosite inorganics —
with improved mechanical strength and superior dimensional accuracy as
compared with fired materials -- and with inherent high temperature
resistance, dimensional stability, and inertness -- have been especially
successful in resistors, thermostats, and for other applications at high
temperature. Ability to be molded with metal inserts also increased
Rosite's suitability for such applications.
In 1957 a significant addition to the Rosite line came into being with the
development of hot-molded, non-tracking, arc-quenching materials. These
materials make it possible to offer increased mechanical and dielectric
strength, over cold-molding, and can lead to refinement in section with
consequent size reduction. Moldability of these materials is excellent,
which results in economy and efficiency in production.
materials were originally developed for electrical applications, the
material research and development at Rostone has continued at a rapid pace
since 1957. There are now new Rosite compositions available which exhibit
such properties as wear resistance, corrosion resistance and low shrinkage.
Each of these has lead to applications in markets heretofore untouched by
Through our years of
experience as custom molders, the Rostone Corporation has developed an
Engineering Staff trained to (1) formulate special compositions for molding
and (2) assist in the development of mechanical designs to achieve moldings
with optimum characteristics.
To keep pace with the demand for plastics, the Rostone Corporation maintains
two modern well-equipped plants located in the Midwest, a plant in Canada,
and an active affiliate in England.
Author Unknown 1971