CELLULOID OBJECTS: THEIR CHEMISTRY AND PRESERVATION
JULIE A. REILLY
1 A HISTORY OF CELLULOSE NITRATE PLASTICS
MANY INSTITUTIONS find that their collections include objects made from early plastics, but little information is available to inform collections management and conservation decisions with regard to these objects. Although there is a fair amount of information available concerning cellulose nitrate conservation materials and film products, there is relatively little published material concerning objects made from cellulose nitrate. In an effort to address this problem, the following information has been compiled concerning the history, composition, manufacture, and deterioration of celluloid objects.
1.2 HISTORICAL SIGNIFICANCE
The impetus for the synthesis, refinement, and manufacture of celluloid was a great rise in the demand for ivory, tortoise shell, and horn objects while the supply of these materials was fixed and the cost high. The search for an imitation of ivory and other natural materials was prompted by fears that the wildlife populations of the world were being rapidly decimated (Friedel 1977, 69).
Celluloid was manufactured commercially in England as early as 1866, when the Parkesine Co. was established by A. Parkes (Kaufman 1963, 119). The company was liquidated in 1868, but the manufacture of celluloid has continued to the present. In the United States, celluloid manufacture began in 1870 with the formation by J.W. Hyatt of the Albany Dental Plate Co. (later the Celluloid Manufacturing Co., which became part of the Celanese Corp.) (Kaufman 1963, 38). The use of the word “celluloid” to describe these plastics was patented by J. W. Hyatt. Most celluloid objects were made between 1846 and 1950. (See table 1 for a history of celluloid invention and usage.)
TABLE 1 Chronology of Cellulose Nitrate-Related Events
Celluloid was first marketed as an imitation ivory used to make small personal objects. Eventually celluloid was used to make an astounding variety of objects (see table 2). However, as Robert Friedel writes: “For the first twenty years that celluloid was on the market, the identification of the material as an imitation substance was paramount in its uses and public description of them (Friedel 1977, 175).”
TABLE 2 Uses of Celluloid
Friedel writes that by the turn of the century celluloid was no longer stereotyped as an imitative material but was valued for its unique qualities in photographic and cinematographic applications:
The large scale adoption of celluloid in photography revolutionized that medium, made another medium, cinematography, technically feasible for the first time, and gave celluloid its most significant breakthrough from imitation. The widespread use of celluloid in photography, and in other areas, drew attention to the material's faults as well as to its uses. This was most clearly demonstrated by the concern over the substance's flammability. Hence came a search for substitutes for celluloid. [Another] … important but unexpected role played by celluloid was as a model of a plastic material—both of what such a material could be and of what it should not be. One of the greatest achievements of celluloid was to provide, by both its virtues and its shortcomings, many of the central themes to be taken up by the seekers of new materials in the 20th century. Celluloid became one of the most important measures by which plastic materials were judged…. As the new plastics … began to emerge …, celluloid began to diminish in importance but not before it had demonstrated the possibilities of an entire class of new substances (Friedel 1977, 205–206).
By the 1950s celluloid was commercially manufactured only to make lacquers and coatings, adhesives, and some textile fibers. Small batches of celluloid are custom made today for replacement parts for musical instruments and other historic objects (Lundberg 1983). Celluloid has many brand names (table 3). Most are obsolete but are often used indiscriminately by those who deal with historic plastics.
TABLE 3 Brand Names of Cellulose Nitrate Products
Much early work was done by chemists and inventors on the characteristics and chemistry of celluloid. Although celluloid led researchers into the realm of polymer science, due to its rapid decline and substitution by new polymers, it has never been studied extensively with the theoretical and instrumental tools available to scientists today. Thus we have a spotty and incomplete understanding of celluloid and its chemical nature.