Polymer composite materials offer engineers the opportunity to design the material as well as the part. Integrating material, part and process design becomes increasingly important as composite materials move from highly specialized uses to the broader durable goods markets. To address these challenges, we are designing and implementing several knowledge-based systems to deal with various aspects of composite design. It is important to realize that these knowledge-based problem solving systems must be integrated with each other as well as with other information systems that might be available to the design engineer. This paper presents a model for a distributed computing environment that integrates problem solving systems, product data exchange models and databases, for the support of design problem solving. The integration architecture is composed of three layers: distributed databases at the core, an intermediate domain specific layer and an outer problem solving layer. The specific focus is on design applications that use polymer composite materials.