What do tomatoes and tape have in common? They can both react with the atmosphere causing chemical changes to occur.
Once picked from the vine, a tomato can be stored at room temperature for a number of days before beginning to rot. It lasts longer in low humidity environments, fewer days in high humidity environments. Higher humidity will hasten the chemical reactions that cause fruit to decay. Low humidity will slow those chemical reactions, as will cooling by refrigeration. Though a lot less tasty, temperature’s heat energy and moisture humidity levels are also major change agents for the chemical components in magnetic tape.
Unlike fruit however, a very common dysfunction of magnetic tape, generally known as Sticky Shed Syndrome, is the result of a natural chemical process known as hydrolysis, which interestingly, can offer the option of a naturally occurring inverse reaction known as reverse hydrolysis. Magnetic tapes generally produced after 1970 consists of 3 laboratory produced chemical components and 2 naturally occurring components. Each of the 5 components has different properties, with different sensitivities to atmospheric reactants such as temperature and humidity. Understanding the chemical properties of the components is key to understanding what unwanted changes are occurring. One important sensitivity is hygroscopic moisture absorption. When a weak component such as the typical urethane binder used for the Carbon Black back coating absorbs water and combines with organic carbon (black) particles, the hydrolysis reaction produces new sticky chemical by-products that then react negatively upon the exposed surface of the magnetic oxide coating one layer up in the reel pack.
What are the new by-products, why do these reactions occur, and is it reversible? Chemical science holds the answers to the complete recovery of existing sticky magnetic tapes and how to manufacture long lasting recording tape free of sticky shed problems. An explanation by chemical science, lab work, microscopic pictures, and before and after results are provided to attain the high goal of high level restoration and preservation of magnetic tape for a very long time. High levels of mechanical and magnetic performance can only occur by first solving the chemical issues.