The Development of the Polyester Tire

Abstract

The introduction of a polyester cord tire to the motoring public in early 1962 repre sented a research and development breakthrough on a goal that has intrigued tire com panies for a decade. This paper describes the following steps in developing a new tire cord fabric deter mining the primary need for a new fiber, programming a fiber study, evaluating cord physical properties, optimizing fabric design, developing maximum performance ad hesive, undertaking tire testing, developing new technology where necessary, conducting volume testing, and finally, adopting in production. In addition to describing the development of the polyester tire, this paper outlines a new concept to predict the potential of a fiber for tire cord usage. This mathematical relationship, called "tire fabric efficiency," rotates (i) the quantity of fabric required in a tire, based on measureable physical properties; (ii) the cost of the fabric; and (iii) the quantity and cost of rubber required in a tire as affected by the fabric characteristies. In relation to this latter factor, it is proposed that a high specific gravity is desirable in a tire cord since it results in rubber savings. It is concluded that polyester represents the ultimate in tire fabric for some time to come because of its outstanding performance and customer acceptance combined with its excellent efficiency and economic potential.