Indoor air quality has become an important for our health and safety matter. All manufacturing processes generate aerosols; the nature and level of this generation vary depending on processes and process step. Epidemiological researches show that metallic dust produced during manufacturing processes in form of fine or ultrafine particles represent significant risk to the health and safety. The health risks range from simple irritation to respiratory bronchitis, asthma and cancer. Consequently, the regulatory agencies of health and safety are urging manufacturers to reduce ultrafine particles and metal dusts. To control and improve the air quality of workplaces, it is important to characterize and determine the behavior of ultrafine particles generated during machining processes.
The main objective of this thesis is to investigate and develop an effective technique for measuring the concentration of manufacturing ultrafine particles rather than the toxicity of these particles. A precise measurement of ultrafine particles will help to develop better correlations between toxicity, nature, shape and size of ultrafine particles and finally acquire ways to predict and limit the harmful particles emission. In this work a method for sampling and substrates preparation adapted for manufacturing ultrafine particles has been developed to obtain relevant information about the emitted particles (concentration, chemical composition, agglomeration degree and shape). A correction methodology of raw data was carried out to improve the measurement. Then this method was applied to the evaluation of manufacturing processes according to the materials, tools and machining strategies.
The results obtained show that the ultrafine particle generation is strongly influenced by material properties and tool geometry. Thus, controlling the material properties and tool geometry implies a reduction the ultrafine particles emission. It is also show that during high speed machining, the emission of metallic particles decreases with the increase of cutting speed. This result is very encouraging from a practical standpoint. It is thus possible to machine parts at very high speeds, which ensures high productivity and limited harmful metallic particles emission.
| Date | 10 May 2012 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Victor Songmene (Supervisor) |
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Djebara, A. (Author),
Songmene (Supervisor),
10 May 2012Student thesis: Doctoral thesis › Doctorate in Engineering: Engineering