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

Publication Date


Document Type


Student Type


Degree Name

Packaging Science(MS)

Department, Program, or Center

Packaging Science (CAST)


Karen L. Proctor

Advisor/Committee Member

Thomas Kausch

Advisor/Committee Member

Daniel Goodwin


Physical copy available from RIT's Wallace Library at TS198.3.P5 M67 2005


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