Abstract: Polyetherimide foam materials, articles that include these foam materials and methods of making these foam materials and articles. The foam extrusion process uses selected blowing agents, equipment design and processing conditions to produce continuously extruded foam with a substantially uniform cell size in a lower density PEI foam, such as 25 to 50 g/L or a higher density PEI foam, such as 120 to 300 g/L. Due to the greater densities that can be produced as well as the characteristics inherent in polyetherimide articles, the resulting foam materials are suitable for a much broader range of applications.

Abstract: A continuous process of making polyetherimide foam materials and articles that include these foam materials. The continuous process is a foam extrusion process that uses selected blowing agents, equipment design and processing conditions to continuously produce extruded foam with a substantially uniform cell size in a wide range of cell densities. Subsequent heating may be used in certain embodiments to remove any residual components from the foam, such as any blowing agents or nucleating agents. Due to the greater densities as well as the characteristics inherent in polyetherimide articles, the resulting foam materials are suitable for a much broader range of applications. The continuous process provides a more cost effective product while also avoiding the use of Freon and/or other agents potentially harmful to the environment.

Abstract: Flame resistant low density foam articles are provided. The foam article is preferably a foam board or a molded expandable foam bead comprised of a thermoplastic resin having adhered thereto a flame-resistance-conferring material serving as a surface flame-resistant barrier in the nature of a thermoplastic or thermosetting coating or laminate or in the nature of a foil, such as aluminum foil.