Galalith
Galalith (artificial horn, milk stone; UK Erinoid ) is an old commercial name for a thermosetting casein - plastic , which in 1897 by Wilhelm Krische and Adolf Spitteler was developed.
History and Applications
The use of milk protein casein as a raw material for plastics is older. In 1531, the “artificial horn” was made by the Benedictine monk Wolfgang Seidel in Bavaria on the basis of a recipe from the Swiss merchant Bartholomäus Schobinger , and the Lilienthal brothers used it to manufacture building blocks in the 19th century.
The Galalith was invented when the Hanoverian printer Wilhelm Krische received an order for white, non-flammable school boards and wanted to cover cardboard with casein. Since these did not want to stick together, he called in the chemist Spitteler. This was unsuccessful for the original project, but a new plastic was discovered. The German (and other) patent to Krische and Spitteler was granted in 1897.
The first button from Galalith was manufactured in 1902 by the Gompertz & Meinrath company, which was then "groundbreaking for the entire button industry in all countries".
Around 1900 Krische and Spitteler sold the German and French patents because they could not finance further industrial development. The driving force was Krische Carl Kunth's brother-in-law. The German patents went to the Vereinigte Gummiwaren-Fabrik Harburg-Wien, the French to a company near Paris, which gave up in 1904. The Harburg company bought back the patents and founded the International Galalith Society Hoff u. Co. AG (IGG) in Harburg with the first general director Carl Kunth. Large sums of money were invested, among other things one promised an alternative for the easily combustible celluloid. Initially, the Krische and Spitteler wet process was used (casein felled by adding rennet or hydrochloric acid, casein was released by adding alkalis, adding colors and other substances, repeated precipitation with acid, dehydration under pressure and cold pressing, hardening in Formaldehyde bath, drying), from 1910 the more economical drying process (processing of ground casein mass, thermoplastic processes, formaldehyde bath, drying). The original patents expired in 1912. Due to the great success, a new factory was built in the Harburg seaport in 1908 and expanded in 1911/12. In 1913, 1500 tons of Galalith were produced per year, up to 1917 mainly through casein imports from abroad (Argentina, New Zealand, and until the outbreak of war France) to 2500 tons.
At the beginning of the 20th century, galalith production became more and more important, and it was used for simple applications such as buttons, belt buckles or cutlery handles. In 1913, for example, 6% of the total amount of milk in the German Empire was used to make Galalith. From the 1920s it was also used in the form of jewelry and was - also through the influence of the Bauhaus and the Wiener Werkstätte - combined with chrome elements and Bakelite at that time . Even today, jewelry made of Galalith is still made and in demand.
When the patents expired in 1912, the dry process was predominantly used and companies were founded in England, the USA (Erinoid, 1914) and France (Lactolites). The generic term was internationally casein formaldehyde plastics (CSF).
In the 1930s, Galalith was also used - with little success - in the electrical industry as insulation, especially for weapon systems. At that time, it was not possible to produce as thick a layer as was required, since uncrosslinked casein remained during production, which reduced the shelf life.
After the First World War, the IGG expanded its range to include phenoplasts (Kerit) and was one of the largest plastics producers in Germany. After most of the production facilities were destroyed in World War II, they were taken over by Harburger Gummiwerke Phoenix AG in 1959 (and in 2004 by Continental AG). Galalith production at Phoenix ceased in 1978.
From the Second World War until around 1980, Galalith was still mainly produced in Great Britain, France, Australia and New Zealand, but production declined significantly as competing petrochemical products were significantly cheaper and less brittle. Due to the increasingly restricted handling of formaldehyde, production was almost completely stopped.
Nowadays, Galalith is only used in niches such as B. with capos , knitting needles, fountain pens or picks .
Manufacturing
Galalith is made from casein and formaldehyde by crosslinking the protein chains via methylene groups with elimination of water . The ground raw casein is moistened with water, mixed with fillers, color solutions and other additives and plasticized by heat and pressure. Semi-finished products such as pipes, rods or just plates and blocks are then produced using special presses. These are hardened by being placed in formaldehyde baths and dried in warm air. The result is a non-combustible material with favorable toughness properties and a warm color. Synthetic horn can be thermoformed between 100 ° C and 120 ° C and then easily machined . The property of its high water absorption capacity, however, severely limits its use.
literature
- Otto Krätz : Stone made of milk. The rise and fall of the Galalith. In: Chemistry in Our Time . 38. 2004, 133-137; doi : 10.1002 / ciuz.200490023 .
- Günter Lattermann: Who invented it? Adolf Spitteler and the invention of the galalith, Ferrum. News from the Iron Library, Georg Fischer AG Foundation, Volume 89, 2017, pp. 26–34
Web links
- Casein formaldehyde on materialarchiv.ch, accessed on March 21, 2017.
- Buttons and combs made of milk. Welt.de, June 8, 2007.
- Early documents and newspaper articles on Erinoid Ltd. in the press kit 20th Century of the ZBW - Leibniz Information Center for Economics .
Individual evidence
- ↑ Galalith at design20.eu
- ↑ From artificial horn made of cheese to plastic semiconductor presse.com, June 14, 2014, print June 15, 2014, accessed August 10, 2016.
- ↑ For hobby alchemists: Instructions for the production of artificial cattle horn Deutsches Kunststoffmuseum, accessed August 10, 2016. - Picture of a bell button from 1910, turned from patterned colored artificial horn.
- ↑ Heinz Lauenroth (Ed.): Hanover. Face of a lively city , Hanover; Berlin: Verlag Dr. Buhrbanck & Co. KG, 1955, pp. 160, 187
- ↑ a b c d Oliver Türk: Material use of renewable raw materials . 1st edition. Springer Vieweg, Wiesbaden 2014, ISBN 978-3-8348-1763-1 , p. 130-133 .
- ^ Silvia Glaser: Galalith. In: Historical plastics in the Germanic National Museum. Verlag des Germanisches Nationalmuseums, Nuremberg 2008, ISBN 978-3-936688-37-5 , pp. 11-12.
- ^ Karlheinz Biederbick: Plastics. 4th edition, Vogel-Verlag, 1977, ISBN 3-8023-0010-6 , p. 172.