Rapid Prediction of Polyester Magnetic Tape Playability Using Water Contact Angles

摘要

The playability and degradation of polyester magnetic media has been an ongoing concern for audio curators, technicians, and hobbyists for decades. As these collections continue to age, users increasingly desire to transfer their contents. However, such a task can be daunting. The necessity of triaging collections for preservation is clear: institutions with large collections may not know the current condition of any given tape, and individual users may have limited equipment and remediation tools available at any given time. This report presents a new, rapid, non-technical tool for evaluating the playability and physical surface of polyester magnetic tapes without needing to place them on playback equipment or use expensive technical instrumentation. Water contact angle, using a small micro-liter sized droplet, was found to accurately predict the physical playback condition of the vast majority of tapes from a sampling of test tapes from the Library of Congress testing labs. This tool provides an appealingly simple and powerful method to directly probe a tape's physical surface. Results could frequently be interpreted by eye, without needing technical processing equipment or software. Total costs for testing equipment were found to be less than $100 USD, allowing for access to a wide range of users.