This paper focuses on flat glass molding technology and summarizes the introduction of seven molding processes between the early 1900s and 1981. These are then divided into four systems. Next, explanations are provided of the types of technology introduced up to 1981 and how they competed, segregated, and eventually discarded. In addition, changes to flat glass molding technology are examined from the perspective of innovation theory, and factors that result in technology segregation are discussed.