Gregory A. Campbell, Ph.D., is Chief Technical Officer at Castle Associates, Jonesport, ME. He was previously professor and departmental chair of chemical engineeering at Clarkson University, NY. He formerly directed a research group at GM Research and managed polymer fabrication at Mobil Chemical Research. He is a Fellow and former Extrusion Board Member of the Society of Plastics Engineers (SPE)
Mark Spalding, Ph.D., is a Fellow in the Materials&Parts Processing Group at The Dow Chemical Company, where he has worked since 1985. He has held a number of technical positions in Corporate R&D, Polystyrene R&D, Plastics R&D, and INCLOSIA* Solutions. He is a Fellow and an Honored Service Member of the Society of Plastics Engineers.