Safely and Efficiently Prepare Environmental-Friendly Gas Generator with High Gas Production Performance

Excellent gas generation and boost rate, low residue rate, and low burning temperature, as well as stable combustion, have always been the key performance of gas generators in the effective functioning of automotive airbag systems. Under the conditions of material properties, formulation, and charge structure being determined, how to safely prepare gas generators with closely contacting component interfaces has become a necessary problem to solve. In this study, vacuum freeze-drying technology was used to prepare KNO3/5 aminotetrazole (5-AT) and KNO3/nitroguanidine (NQ) gas generators. The whole process effectively avoids high temperature and thus ensures operational safety. Compared to physically and mechanically mixed agents, the agents prepared through freeze-drying exhibit stable combustion, with a nearly doubled combustion speed and a reduction of nearly 100°C in combustion temperature. The residual rates of KNO3/5-AT and KNO3/NQ after combustion prepared through freeze-drying are 2.55% and 3.30%, respectively, indicating a more complete combustion process. The maximum combustion pressures reach 97.18 MPa and 88.15 MPa, respectively, with a significant increase in the maximum pressure rise rate. Consequently, the prepared gas generators demonstrate enormous potential in automotive airbag systems.