A new inflator technology has been developed in order to better fulfil major customer specifications: mass, packaging and performances. This new inflator is made of a highly flexible structure and presents a long linear shape. Ratio length/diameter can be from 30 to 300, compared to 2 to 6 for any standard inflator technology. This typical characteristic gives two main advantages to the customer: flexibility makes easy the inflator integration in any module or car environment, and the long linear shape makes gas diffusion more efficient by locating propellant combustion where inflation is needed. Composite propellant production by continuous extrusion process has been well experienced by Autoliv Inflator for more than ten years now and has been used to design a new propellant shape family that fits the flexible inflator inside design. The propellant composition developed for this flexible inflator achieves the most advanced composite propellant level in terms of gas yield and low combustion residue amount. Inflator total performance is more related to inflator length than to inflator volume like in standard technology. More advantages are related to flexibility and linear characteristics: - reduced mass for the inflator and the module, - more efficient inflator packaging inside the module, - lower amount of interface features as the inflator can be implemented directly inside the bag. Hybrid technology has also been developed by connecting a pressure vessel to the pyrotechnical flexible inflator. In all cases, standard initiator technology and electrical connection interface are used. Head Protection Side Airbag modules are the first application to be currently designed with flexible inflator. In that case, the flexibility and the long continuous diffusion are major advantages compared to today inflator technology and should allow to enhance the inflation efficiency of such modules. For the covering abstract see ITRD E126782.
Abstract