ON- POLYMERS - ezio martuscelli

Celluloid films for applications in the field of cinematography and photography were used until the
early 1950s. Since that only films in cellulose triacetate were used for the above applications.
Tapes produced by BASF ( 1934 ) consisting of a foil of cellulose acetate as carrier material, coated
with a lacquer of iron oxide as magnetic pigment and cellulose acetate as binder were used in the
field of magnetic recording following the development of the first magnetophone machine, in 1930,
by the Allgemeine Elektrizitatsgesellschaft [AEG] in Berlin ( see figure 20 ).
Since 1970 flexible films, still more stable than those in cellulose triacetate, and not fire hazard,
made in polyester ( polyethylene terephtalate-PET ) started to be widely used for gelatin coated
films for movie and photos applications [34].
From what above reported it emerges the intercompetition between plastics, process that historically
followed that of substitution of traditional materials with plastics [2,3,25].
FIGURE 20: Early magnetic tape
in flexible plastic films ( see text ).
v) Evidences of substitution of wood and metals with plastics in different application sectors
Of great interest as far as the industrial design is concerned was the substitution of wood material
with plastics in the manufacturing of cabinets for radio. An example of this interesting case is
shown in figure 21 where is documented the replacing of wood with bakelite [35,36].
Plastics were also used in the production of furniture parts, previously made in wood, obtained by
injection molded ( see figure 22 ) [6].
An example of application of plastics in the field of electrical instuments in substitution of metals is
reported in figure 23 [8].
Th reproduction of the one of the first experimental car body totally in thermoformed acrylonitrilebutadiene-styrene
made in 1970 is shown in figure 24 . This model pre-announced the future
application of plastics in the car body industry [9].
vi) Early plastic applications in the field of toys and jewelry
Early exemplaries of toys manufactured in celluloid are reported in figure 25 [37].
Plastics will be more and more used in such an application giving rise to an industrial sector highly
relevant from economic and social pont of view.
At the begining materials such as wood, ceramics and paper-pulp and others were substituted by
plastics.