The purpose of this study is to develop a specification for closure torques that can be used on a production line. The specification must assure that torque will remain adequate to effect a leak free seal while resulting in an ultimate removal that can be achieved by the consumer without difficulty. The challenging aspect of this study is the complexity introduced by using two closure colorants, two distinctly different product formulations, and a capping mechanism that operates at a variable speed of up to three hundred bottles per minute. The research and testing involves dimensional evaluation of bottles and closures, line testing at low, medium, and high production speeds with wet and dry bottle finishes, and five minute, twenty-four hour, seven day, and thirty day removal torque testing. Several conclusions are drawn from the study. First, the bottle finishes must be kept free of product on the filling line. Second, torque decay decreases with time throughout the thirty day period. Third, the two colorants used for the closures do not affect the dimensions or torque values. Finally, the specified removal torque ranges used for production must be associated with the line speed at the time of application.
Library of Congress Subject Headings
Package goods industry--Production control; Assembly-line methods--Production control; Production engineering
Department, Program, or Center
Manufacturing and Mechanical Engineering Technology (CAST)
Brown, Curtis, "A study to determine the optimum closure torque specification for a variable speed packaging line" (1994). Thesis. Rochester Institute of Technology. Accessed from
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