Synthetic resins and their raw materials: A survey of the types and uses of synthetic resins, the organization of the industry, and the trade in resins and raw materials, with particular references to factors essential to tariff consideration. Under the general provisions of section 332, title III, part II, Tariff act of 1930.United States Tariff Commission
Science
Synthetic resins and their raw materials: A survey of the types and uses of synthetic resins, the organization of the industry, and the trade in resins and raw materials, with particular references to factors essential to tariff consideration. Under the general provisions of section 332, title III, part II, Tariff act of 1930.
United States Tariff Commission
Gums and resins industry; Plastics
Polystyrene resin is a clear, colorless, highly thermoplastic molding
material with high insulating property, moisture resistance, inertness,
dimensional stability, and impact strength. It can be molded directly
by heat and pressure, and the molded articles are remarkably resistant
to discoloration by light. Polystyrene has a dielectric constant of
2.6, a power factor of 0.02 percent, and is equivalent to fused quartz
as an electrical insulator of low dielectric loss. Films of 0.002 inch
thickness have a dielectric strength of more than 2,000 volts per mil
thickness, which is better than that of any other available synthetic
resin and even better than that of shellac. The tensile strength of
the resin is 5,500 to 7,000 pounds per square inch, and its impact
resistance remains unchanged at temperatures as low as minus 70° C. It
transmits all wave lengths of light down to 3,000 Angstrom units.
Polystyrene is adapted to large scale production of transparent,
translucent, and opaque moldings in a wide variety of colors. It is
easily molded by injection processes, softening at about 150° F. and is
molded at 300° to 375° F., under 3,000 to 30,000 pounds pressure per
square inch. As much as 40 percent filler may be used without seriously
affecting the tensile strength, although the filler does affect the
dielectric properties. Since the resin is thermoplastic there is no waste
in the molding operation; scrap material may be reground and used again.
The unusual properties of these polystyrene resins should give them
widespread applications when the cost is low enough to make them
competitive with other materials. Potentially large volume outlets are
in radio frequency insulation; in dentures because of the strength, low
specific gravity, ease of coloring, and absence of odor and taste of the
material; in electrical parts for submarine and aircraft storage battery
cases and separators; and for the manufacture of glass eyes.
Other possible applications of polystyrene resins are in metal lacquers
and in light colored enamels. Their toughness and light color, together
with their solubility in cheap solvents, suggest their use for these
purposes. Such lacquers are said to be quick-drying, resistant to water,
and moderately so to acids and alkalies.
Production in the United States.
For a number of years, the Naugatuck Chemical Division of the United
States Rubber Co. produced small quantities of polystyrene resins, which
were marketed under the trade name Victron when for general purposes and
under the trade name Marvelyn when for use in dentures. Little progress
was made because of high costs and failure to produce a water-white
product. The sales price was between $1.50 and $2 per pound. Early
in 1937 the Naugatuck Chemical Division transferred its patents on
polystyrene resins to the Carbide and Carbon Chemicals Corporation.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account