Compared to vulcanized rubber, uncured rubber has
relatively few uses. It is used for cements; for adhesive, insulating, and
friction tapes; and for crepe rubber used in insulating blankets and footwear.
Vulcanized rubber, on the other hand, has numerous applications. Resistance to
abrasion makes softer kinds of rubber valuable for the treads of vehicle tires
and conveyor belts, and makes hard rubber valuable for pump housings and piping
used in the handling of abrasive sludge.
The flexibility of rubber is often used in hose,
tires, and rollers for a wide variety of devices ranging from domestic clothes
wringers to printing presses; its elasticity makes it suitable for various kinds
of shock absorbers and for specialized machinery mountings designed to reduce
vibration. Being relatively impermeable to gases, rubber is useful in the
manufacture of articles such as air hoses, balloons, balls, and cushions. The
resistance of rubber to water and to the action of most fluid chemicals has led
to its use in rainwear, diving gear, and chemical and medicinal tubing, and as a
lining for storage tanks, processing equipment, and railroad tank cars. Because
of their electrical resistance, soft rubber goods are used as insulation and for
protective gloves, shoes, and blankets; hard rubber is used for articles such as
telephone housings, parts for radio sets, meters, and other electrical
instruments. The coefficient of friction of rubber, which is high on dry
surfaces and low on wet surfaces, leads to the use of rubber both for
power-transmission belting and for water-lubricated bearings in deep-well pumps.