Abstract

Almost all the domestic aerosol products use hydrocarbon propellants (i.e., butane and propane) in which a high flash vaporisation provides a good atomisation. However, according to the 2015 United Nations Climate Change Conference agreed in Paris and COP 26, Glasgow, UK, these propellants have the adverse climatic effects due to the level of VOC’s (Volatile Organic Compound) which can lead to greenhouse gases. The agreement has given an im-petus to industry to significantly reduce these harmful gases by 2030. Therefore, an alternative energy is required to replace the corresponding hydrocarbon compositions by utilising safer propellant such as compressed gas (i.e., Nitrogen or air). Although the energy of the compressed gas is about 700 times lower than the hydrocarbon propellants, thus spray pattern is not constant through life of the can and as the product is evacuating, the particle size will increase rapidly, and discharge rate will drop sharply. This causes a huge drop out and wetness which is not acceptable for consumers. This article describes the new valving arrangement, called here ‘EcoValve’ that utilises inert gases propellants and ‘bubbly flow’ concept. The valve designed on the bases of two-fluid atomisation and uses all liquid hairspray products that have either solvent or non-solvent compositions. The major challenge of this change is to be able to provide equivalent exothermic energy as in LPG (Liquified Petroleum Gas) via the inert gases to assist good atomisation through the valving system. Furthermore, LPG propellant causes flash vaporisation, thus providing consistent discharge rate and droplet size with adequate wetness and spray dropout through the pack life., The so-called EcoValve and the matching actuators that presented in this artical uses inert gas propellant such as Nitrogen with and without solvent products of different leading brands. Constant discharge rates through life of the can, ranging from 0.4g/s up to 1g/s were obtained with particle size of 40μm and 60μm, depending on the application. Moreover, the wetness and dropout of the corresponding sprays were characterised and also highlighted. In addition, all results, where appropriate, compared with conventional domestic aerosol valve_product using LPG. The new ‘EcoValve’ for domestic aerosol products has fully been piloted and being commercialized.

Keywords:Aerosol; Domestic; Two fluid; Particle size; Discharge rate; VOC; Compressed gas; Atomisation; Hair spray; Solvent