Two different case studies were examined to determine how different liner structures or plastic additives affect torque degradation. The first case study examined how torque is affected with and without the use of a zinc stearate plastic additive. The second case study examined how torque retention differs between a synthetic liner and a pulp board backed liner structure. Both torque studies provided a starting point for the application torque range for use in production. The torque studies were used to outline the necessary application torque so that the child resistant closures obtain and maintain the proper torque level over time through to the end user. The torque testing was also used to prove torque equivalency within each of the package systems for both case studies.
Library of Congress Subject Headings
Plastics in packaging--Research; Polymers--Mechanical properties--Research; Child-resistant packaging; Torque; Polypropylene
Department, Program, or Center
Packaging Science (CAST)
Karen L. Proctor
Moszak, David Garrett, "Torque Retention with Polypropylene Bottles" (2005). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus