August-Wilhelm Siekmann, 81, chairman of the influential German kitchen manufacturer SieMatic Corp., died Aug. 29 after a brief but serious illness. In 1955 at the age of 32 he took over management of SieMatic Möbelwerke in Löhne, Germany, a company founded by his father. Later, he became known as the company's patriarch. Today SieMatic exports to more than 50 countries worldwide.