Creep of carbonated plastic beverage bottles

Long‐term performance of carbonated plastic beverage bottles depends on a number of critical factors. Testing to predict the effects of these factors is expensive and time‐consuming. Many of these factors are interdependent. The presence of more than one critical factor in a given test makes the analysis of data difficult. The separation and prediction of the contribution of any one factor to long‐term performance is complex even for the single composition studied, a rubber‐modified high acrylonitrile resin. In addition to superior gas barrier properties, the container should exhibit a high degree of creep resistance. Visible manifestations of creep are reflected in gross dimensional changes of the bottle and consequent loss in carbonation. The purpose of this paper is to examine creep deformation of the bottle and its implications on bottle performance. Various factors contributing to the creep are also briefly analyzed. Since the ultimate goal is to predict creep, the merits of relevant short‐term tests in this context are discussed. Finally, the data from short‐term tests are compared with creep data obtained on bottles that were subjected to long‐term tests.