Toluene diisocyanate, referred to as TDI. This is a liquid material used to produce flexible polyurethane foam. Covestro has been producing TDI in Domagan for 55 years and has now produced 3 million tons.
The TDI plant in the Domagen Chemical Park alone is sufficient to produce 200,000 mattresses per day. But high-tech materials can not only ensure the dream of sleeping. Most products enter the automotive industry to make car seats. The special isocyanate also leads the fashion trend: as a shoulder pad or bra cup, it can create a delicate figure.
"The production of TDI is one of our priorities at Domagen. At the same time, the TDI plant is a milestone in terms of efficiency and environmental compatibility. With state-of-the-art plant technology, we An important raw material that can produce flexible foam in a resource-efficient and environmentally friendly manner. "
55-year history of TDI production
The success story of the Dormagen factory began in 1964, west of where it is today. TDI output has steadily increased from 24,000 tons / year to 75,000 tons / year. In 2014, a 300,000-ton / year world-scale TDI plant was put into operation and put into production in Ostwerk. It fits very well into the structure of the local plant: the starting product, toluenediamine (TDA), comes from a neighboring plant. The Domagen plant also produces raw materials such as toluene, hydrogen and nitric acid.
Dr. Andreas Rausch, head of the Domagen TDI plant, explained: "The new plant is one of the three TDI production bases in the world, and the other two are located in the south of China and Baytown in the United States. Technology, and the technical knowledge of the employees of the old factory ensured the continuity of production. In its predecessor business, GPP technology (vapor phase phosgenation) was developed in 2004. Compared with the traditional liquid phosgenation to date, its consumption of Solvent is reduced by 80% and energy consumption is reduced by 60%.
Another feature is that the transportation company responsible for TDI storage, loading and transportation remains the same at Westwerk. TDI enters the company's storage tanks through a pipeline, which is then filled and shipped to the customer. They produce flexible foams suitable for various applications.
How is foam made of TDI?
Foam is formed by adding polyol, which is combined with TDI in the polyaddition reaction. The mixing ratio varies depending on the type of the polyol and the nature of the foam. The addition of water produces gaseous carbon dioxide in the reaction, which no longer escapes from the viscous material and forms bubbles. Increased the volume many times.
The application of TDI is diversified and constantly developed, and its basic concept has a history of more than 70 years. Otto Bayer, the inventor of polyurethane chemistry, was already looking for raw materials for fully synthetic fibers similar to nylon in the late 1930s. A failed attempt in 1941 produced a completely blistering swelling. This is the birth of the bubble!