Galalith

DPN ( artificial horn, milk stone; UK Erinoid ) is an old trade name for a casein plastic, which was developed in 1897 by Wilhelm and Adolf Krische Spitteler.

DPN produced from casein and formaldehyde by polycondensation. The ground Rohcasein is moistened with water, mixed with fillers, color solutions and other additives and plasticized by heat and pressure. By special presses then arise semifinished products, such as pipes, rods or just plates and blocks. These are cured by soaking in formaldehyde baths and dried in warm air. The result is a non-combustible material with low toughness and a warm tone. Art Horn may be between 100 and 120 ° C hot-formed and are subsequently processed easily machined. The property to its high water absorption capacity restricts its use again a strong. DPN was prepared to about the mid-1930s in large quantities in Germany and first inter alia, for the manufacture of buttons, jewelery and cutlery handles used, and later also for the insulation of electrical equipment, in particular weapons systems.

After the end of World War II Galalith lost by developing new, fully synthetic plastics gradually in importance, because these were, first, in their cheaper raw materials ( oil instead of milk ) and secondly less crumbly than DPN. Due to its material properties Galalith still leads a niche at about knitting needles or picks.