Mismatch between jar opening demands and wrist torque strength of consumers in Iran

Abstract

This study evaluated the potential mismatch between vacuum-sealed jar opening demands and wrist torque strength of 758 (384 males and 374 females) participants aged 5-74 years in Iran. Wrist ulnar/radial (U/R) torque strength of participants and required torque for opening the existing jars (with 2 different sizes - 65 mm and 85 mm diameter lids) were measured using a digital angle torque adaptor and then compared together to identify any potential mismatch between them. The mismatch percentages were defined as the number of participants whose maximal wrist U/R torque strength were lower than the minimum required torque strength for opening the vacuum-sealed jars. Minimum required torque strength for opening the existing 65 mm and 85 mm vacuum-sealed jars were 4.1 Nm and 6.6 Nm, respectively (range = 4.1 Nm to 10.2 Nm). A considerable mismatch (range = 25%-100%) was found between the required torque strength for opening the existing jars and the wrist U/R torque strength of the study population, particularly for females and those aged 5-9 years. A torque limit of 1.8 Nm was proposed for opening jars for the entire population.

Keywords: Force; Openability; Package design; Packaging; Twisting.