celluloid
As celluloid (also celluloid ) refers to a group of synthetic compounds, consisting of cellulose nitrate and camphor are prepared. Celluloid is believed to be the first thermoplastic . It's easy to melt and shape. Celluloid made it possible for the first time to mass-produce imitations of luxury items from natural products such as ivory , amber , coral , lapis lazuli , ebony , horny substance , tortoiseshell or mother-of-pearl (die-casting technology).
Manufacturing
Celluloid is made by mixing cellulose nitrate with camphor . Camphor is used here as a plasticizer for the cellulose nitrate.
History and Development
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The first celluloid was produced by Alexander Parkes in 1856 , but he did not manage to use his invention ( Parkesine ). The name celluloid originated from the trademark "Celluloïd" registered in 1870 by the Celluloid Manufacturing Company , which manufactured the celluloids that were protected by the patents of John Wesley Hyatt . Hyatt had been looking for an inexpensive substitute for the ivory used in billiard balls , developing a process where heat and pressure made it easier to manufacture. In 1878 he bought Parkesine's patent for Parkesine .
In the late 1880s, celluloids were developed as a clear support for photographic films . Both Hannibal Goodwin (1887) and the Eastman Company (1888) received patents for a celluloid film . Goodwin and the investors to whom he later sold his patents won patent infringement proceedings against the Eastman Kodak Company in 1898 .
Before the First World War, around 12,700,000 kg of celluloid were produced annually in Germany.
On January 1, 1951, film factories around the world officially ceased manufacturing raw celluloid film. It was not until the mid-1950s that stocks were sold out, and it was only when the material was banned as a highly flammable hazardous substance in more and more individual countries that it also disappeared from movie theaters.
In a dry environment, the water content of celluloid film gradually decreases. Over time, the substance takes on an explosive character and can ignite spontaneously. For this reason, nitrocellulose films , for example in the Federal Film Archive , may only be stored under special safety precautions.
use
With the development of celluloid film, the cornerstone for photographic film was laid in today's understanding of the widespread roll film and 35mm film , which now competed with the photographic plate and ultimately led to the development of cinema films .
Marked As early as 1869, Daniel Spill, a partner of Alexander Parkes, the plastic Xylonite (an evolution of Parkesine ) to be suitable for it, "Gears and Friction Wheels" ( gears and friction wheels ) and "Bearings for Machinery" ( plain bearings manufacture).
Celluloids were widely used as thermoplastics in the 19th and first half of the 20th century. Combs, knife handles, ballpoint pen housings, glasses frames and toys were made from this material. However, it was highly flammable and weathered, which is why it has been replaced by cellulose acetate plastics and, since 1950, more and more by PET .
A celluloid ring holds the firing pin spring in chemical-mechanical long-term detonators (colloquially "acid detonators ", although actually no acid is contained). When the bomb is dropped, a spindle is screwed into the detonator through a previously unsecured wind turbine, which destroys a glass ampoule with acetone there . The acetone then dissolves the celluloid and the release balls are pressed into the soft celluloid by the spring force, removing the firing pin spring lock. The detonation delay with long-term detonators can be varied between 2 and 144 hours using different acetone concentrations and different numbers of layers of celluloid rings. A large number of the bomb duds, which are still dangerous today, are equipped with such detonators, which for various reasons did not trigger the detonation even after the desired time delay.
A typical celluloid contains about 70 to 80 parts of nitrocellulose , nitrated to 11% nitrogen, 30 parts of camphor , 0 to 14 parts of dye, 1 to 5 parts of ethanol and other stabilizers and additives that make the plastic more durable and flame-resistant.
In the musical instrument industry, celluloid still plays a role as a material for picks and foils in drum construction. The surrounds of high-quality musical instruments (bindings) are still made from celluloid.
Table tennis balls were traditionally made from celluloid. In order to achieve a material that is not classified as dangerous and whose raw materials are sufficiently permanently available worldwide, the ball manufacturers and the ITTF agreed in 2014, after a few years of research and development, on the so-called plastic ball . (Apparently nobody reveals which plastic it is actually made of.) While only plastic balls were quickly used in competitions at the federal level, celluloid balls were used for a long time at the regional level due to their higher resistance.
Celluloid is still used as a barrel material for very high-quality pens and fountain pens , as the haptic properties of celluloid have so far not been achieved with other plastics.
Smoke bomb
If celluloid is reacted at low temperature without an open flame, strong smoke develops, similar to military smoke grenades . A large number of building instructions are circulating on the Internet, mostly based on shredded table tennis balls.
literature
- Hans-Josef Endres, Andrea Siebert-Raths: Technical biopolymers. Hanser-Verlag, Munich 2009. ISBN 978-3-446-41683-3 .
- FM Feldhaus: celluloid. With eight illustrations based on original photographs . In: Reclams Universum 26.2 (1910), pp. 939-943.
- Silvia Glaser: Historical plastics in the Germanic National Museum . Verlag des Germanisches Nationalmuseums , Nuremberg 2008, ISBN 978-3-936688-37-5
Web links
Individual evidence
- ↑ Clément L., Rivière C., Bratring K .: The cellulose The cellulose compounds and their technical application . Springer Berlin Heidelberg, Berlin, Heidelberg 1923, ISBN 978-3-662-28859-7 , pp. 104 .
- ^ University of Bayreuth, Didactics of Chemistry; Version of August 22, 2011 ( Memento of November 28, 2012 in the Internet Archive )
- ↑ Federal Archives, information about nitrocellulose film ( Memento from February 19, 2014 in the Internet Archive )
- ↑ Stephen Fenichell: "Plastic - The Making of a Synthetic Century", ISBN 0-88730-732-9 , quoted from Ullrich Höltkemeier: Fit, also for Extreme , in: Konstruktionspraxis Spezial Antriebstechnik, April 2013.
- ^ Silvia Glaser: Celluloid . In: Historical plastics in the Germanic National Museum . Verlag des Germanisches Nationalmuseums, Nuremberg 2008, ISBN 978-3-936688-37-5 , pp. 12-14.
- ↑ Hans Fremken (BDFWT): Long-term detonators ( Memento from January 16, 2014 in the Internet Archive ) (PDF; 529 kB).
- ↑ Video: 100 Ping Pong Ball Smoke Bomb on YouTube , July 23, 2008.