Designing of Half-Masks of Filtering Respirators

Abstract

Introduction. Diseases of the respiratory system head the list of occupational diseases. They are caused by pollution of the working zone air with harmful aerodispersed particles, use of improper individual respiratory protective devices.
Problem Statement. The efficiency of filtering respirators depends on two components: time of protective effect and insulating properties of half-masks. This requires conducting relevant research in order to design the half-masks which allow providing high insulating properties.
Purpose. Improvement of protective effect of filtering respirators by improving their design with respect to anthropometric peculiarities of workers’ faces.
Materials and Methods. To develop the surface of a half-mask, the equation of free energy of a bent optional plate was used, which is outlined with a two-dimensional spline-surface, its unknown coefficients are defined by the method of proportional parts based on the data of three dimensional coordinates of the key points of anthropometric facial features.
Results. Regularities of forming the surface of half-masks were defined based on the data of three dimensional coordinates of the key points of anthropometric facial features. A method was developed for measuring the temperature of obturator surface with a thermal imagery device based on output signal processing, which allows carrying out on-line control of areas where gaps occur along the obturation line as well as defining deterioration of insulating properties of a dust mask and estimating its protection factor.
Conclusion. The algorithm of half-mask design was developed with respect to the results of 3D scanning of faces, digital models of head developing as well as half-masks surface and obturator construction associated with them. The reasonable parameters of filtering box, size of ioutlet for providing the minimum pressure difference and regular dust distribution on filtering surface were determined.