Differenze tra le versioni di "Galalith"

Versione attuale delle 00:07, 15 ott 2020

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Galalite/en

@@ Riga 1: / Riga 1: @@
-<includeonly>[[Galalith]]</includeonly><noinclude>Galalith</noinclude> is a <includeonly>material</includeonly><noinclude>[[material]]</noinclude> invented in 1897<ref>by Adolph Spitteler and Wilhelm Krische, who then patented it in 1899, see the relevant [http://en.wikipedia.org/wiki/Galalite entry] on Wikipedia.</ref> created from the formaldehyde treatment of casein (the milk protein), so much so that it is often simplistically called [[casein]], although such an indication is not absolutely correct because hardened casein does not have the chemical and mechanical resistance characteristics of galalith, whose name derives from the union of the Greek words ''gala'' (milk) and ''lithos'' (stone).
+#REDIRECT[[Galalite/en]]
-The material is produced by a process in which casein is kneaded and colored and then processed to produce sheets, bars or slabs; these are then treated by immersion in a diluted solution of formaldehyde that causes, with a very slow reaction, the progressive hardening. Finally the material obtained is dried and then can be processed. The production process is therefore very slow (for thicknesses of 2.5 cm it may take up to one year of immersion), moreover, even if the galalite sheets can be hot bent, mould production is not possible, which makes the processing of the material more complex.
+[[Category:Glossary]]
+[[Category:Technology]]
-One of the most important characteristics of this material is instead the ease of coloring, which allows you to create endless variations and imitate different materials, so that it was also called artificial horn. The coloring in fact, in addition to the mixing of colors in the production phase, can be obtained, thanks to the high porosity of the material, in a second phase by immersing the galalith in coloring baths to obtain the absorption of pigments. The new material had a great diffusion in the production of buttons, where it is still used today, and for the substitution of ivory in the piano keys cover.
-Galalith was used in the production of fountain pens by some companies around the '20s, when the research for materials that could replace the [[hard rubber]] began. In particular [[Sheaffer]] used it for some models produced for a very short time, which, because of the problems they had, were reused as pens for temporary replacement. [[Parker]] adopted galalith for the production of the fountain pens of the series called [[Ivorine]], even if the most extensive use was probably made by [[Conway Stewart]] for the production of some of his most original colored pens.
-However, galalith was not very successful and was quickly abandoned with the advent of [[celluloid]]. Its porosity in fact makes it strongly hygroscopic, with the tendency to expand with humidity, which leads to problems of mechanical stability. Even worse, again for this characteristic, its resistance to ink, which tends to produce permanent stains. In addition, immersion in water (even for just a few hours) involves an expansion (up to 10%) and a softening of the material, with destructive consequences as a subsequent drying it will lose its original shape. Finally, with time the material tends to present cracks (usually they occur for long exposure to light and are believed to be caused by changes in moisture) that are only apparently superficial and can not be removed.
-For all these reasons, with the exception of [[Conway Stewart]] who continued to produce pens in this material until the 1930s, in the mid 1920s galalith was totally abandoned in favor of [[celluloid]], which, combined with the fragility of the material that makes them difficult to preserve, has meant that pens made with it, in particular [[Sheaffer]] and [[Parker]], are very rare.
-<noincludes>
-== Notes ==
-<references/>
-== External References ==
-* [https://web.archive.org/web/20080219044750/http://www.pentrace.net/penbase/Data_Returns/full_article.asp?ID=264] First article on galalith
-* [https://web.archive.org/web/20070814110812/http://www.pentrace.net/penbase/Data_Returns/full_article.asp?ID=276] Second article on galalith
-* [https://web.archive.org/web/20130616220311/http://www.pentrace.net/penbase/Data_Returns/full_article.asp?id=279] Third article on galalith
-* [https://web.archive.org/web/20130616221302/http://www.pentrace.net/penbase/Data_Returns/full_article.asp?id=296] Fourth article on galalith
-[[Category:Glossary]]]
 [[Category:Materials]]
-</Noinclude>

Differenze tra le versioni di "Galalith"

Versione attuale delle 00:07, 15 ott 2020

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