The 73rd Glass Problem Conference is organized according to the following themes: Glass Melting, Melting, Raw Materials, Batching, and Recycling, Coatings, Strengthening, and Other Topics, Refractories, and Process Control & Modeling

This issue contains a collection of papers presented at the 72nd Conference on Glass Problems at The Ohio State University, Columbus, Ohio. Topics covered include glass melting; refractories; process control; legislation safety, and emissions; recycling and batch wetting.

The 81st Conference on Glass Problems (GPC) was organized by the Kazuo Inamori School of Engineering, The New York State College of Ceramics, Alfred University, Alfred, NY 14802 and The Glass Manufacturing Industry Council (GMIC), Westerville, OH 43082. The Program Director was S. K. Sundaram, Inamori Professor of Materials Science and Engineering, Kazuo Inamori School of Engineering, The New York State College of Ceramics, Alfred University, Alfred, NY 14802. The Conference Director was Bob Lipetz, Executive Director, Glass Manufacturing Industry Council (GMIC), Westerville, OH 43082. The GPC Advisory Board (AB) included the Program Director, the Conference Director, and several industry representatives. The Board assembled the technical program. Donna Banks of the GMIC coordinated the events and provided support. Due to world-wide COVID-19 pandemic, the conference was a virtual event. It started with a full-day plenary session followed by technical sessions.