Baydur 641 IBS is a rigid polyurethane structural foam system used in the reaction injection molding (RIM) process. This system is supplied as two reactive liquid components and is typically used with a blowing paste purchased separately. Component A is a polymeric diphenylmethane diisocyanate (PMDI). Component B is a formulated polyol system containing no CFC- or HCFC-blowing additives. The blowing paste is Baydur PU-1731.

The Baydur 641 IBS system is used in the industrial and medical equipment markets for applications requiring dimensional stability and excellent surface finish, such as, rollers for photographic and X-ray film processing equipment. As with any product, use of Baydur 641 IBS system in a given application must be tested (including field testing, etc.) in advance by the user to determine suitability.