Autoliv Asp, Incorporated

Roger Bradford

Ivan V Mendenhall

Brett Hussey

Gary K Lund

Thomas Cronin

Methods for making a pressed monolithic gas generant for an inflatable restraint device (for example, an airbag system for a vehicle) are provided. The methods include admixing a gas generant material with a ballistic performance modifier to form a mixture. The mixture is granulated. Then, a pressed monolithic gas generant grain is formed by applying pressure to the granulated mixture, where the grain has an actual density of at least about 95% of the maximum theoretical density. The pressure may be applied in a controlled manner to both side of the gas generant material in a die cavity, and removing formed grain from die cavity while maintaining some pressure to both sides of the grain, thereby further improving various pyrotechnic properties. The methods of the disclosure provide pyrotechnic compositions that are economical to manufacture, have improved burn rate, combustion profile, effluent quality, strength, durability, and integrity of the grain, while having a consistent shape between different production lots.

Methods of manufacturing monolithic generant grains

Compositions and methods relating to gas generants used in inflatable restraint systems. The gas generant grains formed via spray drying techniques of the present disclosure provide superior performance, including high burn rates and high gas yields. Further, processing of the gas generant grain products can be streamlined. Such gas generants include by way of non-limiting example, guanidine nitrate, basic copper nitrate, and a secondary oxidizer, such as potassium perchlorate.

High performance gas generating compositions

A gas generant for an inflatable restraint device (for example, an airbag system for a vehicle) is a monolithic compressed solid that has a linear burn rate of greater than or equal to about 1.6 inches per second at a pressure of about 3,000 pounds per square inch. The gas generant can be in the form of an annular disk having a plurality of apertures. The gas generant may be substantially free of binder and may have a low initial surface area which progressively increases during burning. The gas generant provides a gas generation profile that improves restraint of vehicle occupants, including those occupants that are out-of-position. Additionally, the shaped gas generant decreases occupant exposure to toxic effluent combustion products and solid respirable particulates.

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Malad, ID, United States of America

Roger Bradford