Design of Bumpers for Impact Resistant Gloves

Abstract

Hand injuries, due to impact, are common workplace injuries. Many work gloves afford impact protection through design of add-on components known as bumpers. Glove design criteria are complex (e.g., limitations from human factors, dexterity, use case, hand size variability) and commercial bumpers exhibit a wide variation in their geometry, placement, colour, and material of construction. In addition, manufacturers aim to meet or exceed standards for glove testing and rating (e.g., cut, abrasion, puncture, chemical, and impact resistance). Polymeric bumper materials simultaneously meet many design criteria (e.g., low stiffness for dexterity, manufacturing into complex geometries, high volume production, and high energy absorption on a mass basis); however, current knowledge gaps of how polymer material properties and dimensions reduce the transmitted force of impacts provided motivation for this work. Drop testing was performed using the ANSI/ISEA 138-2019 impact standard as a guideline. Due to the multitude of variables involved, no single ideal design or material was identified. Nonetheless, insights from this work include: 1) different materials, and their local thickness and dimensions, have potential to reduce transmitted force and should be further explored; 2) a characteristic length scale (associated with the standard impact testing apparatus) was identified and produced a transition in material behaviour resulting in a dip in transmitted force; 3) the testing locations of the impact standard, when contrasted against injury statistics, should be revisited against high frequency injury locations for greater potential protection. The findings of this work culminate in a preliminary design for a prototype for future testing.