Pneumatic LDPE Shock Absorbers for the Protection of the Human Head Against Impact

The problem of protecting the head from mechanical impact injuries has been known since ancient times. Currently, there is a great deal of interest in individual means of transport such as traditional and electric bicycles, electric scooters, segways, etc. The rise in popularity of electric scooters is particularly evident in urban and suburban areas. The specialist literature provides information on accidents involving users of individual means of transport, including users of relatively new electric scooters. The literature also contains several studies on head protection for people who need to use personal protective equipment, such as industrial safety helmets. Despite the ever-increasing number of new technical solutions used in the production of protective helmets in the broad sense, the problem of effective protection against the risk of head injury in an accident remains relevant. The article presents the results of impact tests on pneumatic shock absorbers made of LDPE, which provide conceptual protection for the head and possibly other parts of the body or fragile objects against the effects of impact loads. The absorbers presented can also be used in several different safety features, e.g., car headliners. The mechanical properties of the LDPE absorbers were compared with those of the EPS100 polystyrene, which is used in popular bicycle and motorcycle helmets as an impact energy dissipating element. The research methodology can be an interesting proposition for researchers dealing with the issues of impacts and diagnostics of materials and structures that dissipate impact energy. LDPE pneumatic absorbers, while maintaining controlled air flow, are a viable alternative to EPS100 polystyrene foam. The research carried out, using analytical relationships, allowed the following objectives to be achieved: (1) experimental tests of impact absorbers, (2) processing the results by using approximation functions, (3) preparation of dynamic characteristics, and (4) evaluation of the protective effectiveness of pneumatic and polystyrene absorbers.