Application of air-bubble cushioning to improve the shock absorption performance of type I industrial helmets

•Shock absorption performance of industrial helmets were improved using air bubble.•Type I drop impact tests were performed according to ANSI Z89.1 standard.•The air bubble cushioning effects on the helmets' shock absorption were analyzed.•Air bubble cushioning increases helmets’ shock absorption for large impact forces.•The air bubble shock reduction may also be used for other types of helmets.