This thermosetting plastic material is made from melamine and formaldehyde. From thermosetting plastics, alkyds and melamine resins are better than phenolic resins. See also AT-10 resin, melamine resin. Porcelain or melamine containers are used for display. Cyanic acid polymerizes to cyanuric acid, which condenses with the liberated ammonia forming melamine. Stones can also be made from Melamine resin. Cyanuric acid can be produced by hydrolysis of crude or waste melamine followed by crystallization. In 1938 melamine thermosetting resin was developed by American Cyanamid Company. It has been considered to be more toxic than either melamine or cyanuric acid alone. Urea melamine resins offer water resistance with more melamine offering higher resistance. Lignin, naphthalene, and melamine sulfonate superplasticisers are organic polymers. Mengniu was among those named for having powdered milk samples which tested positive for melamine. Heinz recalled cases of baby cereal in Hong Kong after discovering they contained melamine. Graphitic carbon nitride can be made by polymerization of cyanamide, dicyandiamide or melamine. The slurry is further concentrated and crystallized to yield melamine.