T-T INDICATING SYSTEMS
Abstract
The original concept of developing T-T (time-temperature) indicating systems which can be related to product deterioration has been established and proven for several possible systems. The approach was that both useful life of a storage item and the amount of oxygen permeating a plastic film are exponential functions of temperature. By inclosing a suitable oxygen-reacting chemical system in a plastic pouch, the amount of reaction which occurs depends upon the amount of oxygen permeating the film which in turn is effectively controlled by time and temperature. The concept feasibility has been explored and proven through studies of the following four oxidizable chemical systems: The redox dye system, using an anthraquinone-zinc solution, has proven capable of conveying written messages to indicate the end of the useful life of a storage item; The inorganic system, through the color change in two stages of FeCl2- H3PO4 solution can also be used to convey information; Both anthraquinone-zinc and FeCl2-H3PO4 systems have been shown to be stable to light and heat; and The enzyme and rubber sheet systems also could be adopted for indicating time and temperature; however, their practical applications are limited to special situations. These studies have shown that the basic design concept provides excellent versatility.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1970
- Accession Number
- AD0713542
Entities
People
- J. D. Loconti
- K. H. Hu
Organizations
- United States Army Soldier Systems Center