Sigg Switzerland AG is a Swiss manufacturing company with its headquarters in Frauenfeld. Sigg bottles are bottles designed and manufactured in Switzerland from aluminum and polypropylene or in China from stainless steel and glass. The company is famous because of the iconic shape its classic bottle and numerous designs which have led to its addition to the permanent design collection of the New York Museum of Modern Art. History The company was founded in Biel in 1908 by Ferdinand Sigg und Xavier Küng under the name Küng, Sigg & Cie. and produced kitchenware, bottles and electrical appliances from aluminum. In 1916 the company moved to Frauenfeld and changed the name to SIGG Aluminiumfabrik. Since 1998, the company has concentrated on the manufacture of bottles. According to market research, the company name is known by 70 percent of people in German-speaking countries. Through the 1980s Sigg manufactured impact-extruded aluminum bottles for stove fuel storage and transport, popular with mountaineers, hikers and campers. The fuel bottles superficially resemble the water bottles, but lack the special linings of the latter. Now the company doesn't manufacture fuel bottles anymore. On February 5, 2016, the Chinese company Haers Vacuum Containers announced it acquired the bottle manufacturer for 16.1 million Swiss franc ($16.02 million). Interchangeability All Sigg bottles use the same diameter head and thread system, which results in interchangeability of bottles and caps. Different cap styles exist, such as a normal screw on cap with loop, caps with glow-in-the-dark markers, sports-bottle caps and caps with added protection from dust. Aluminum bottles The aluminum bottles are made by an extruding press which forms an aluminum puck into a cylinder in a single movement after which it is pressed into one of several possible bottle sizes. A separate threading ring is inserted and secured. Once the bottle has been formed, it is cleaned and the interior is sprayed with a food-compatible stove enamel which is heated while the outside is coated and heat bonded with powder paint. Aluminum bottles are resistant to shocks and disformations, are lightweight, and protect the contents from light. The interior coating is flexible and is unlikely to break or crack during deformations. Sigg bottles have been determined by Backpacker magazine to be the "world's toughest water bottle" when they fired golf balls at the water bottles with a 100-pound cannon. The bottle with its internal liner and secure cap allow for carbonated