METHOD FOR ASSESSING COLOR FASTNESS OF A TEXTILE MATERIAL AGAINST THE ACTION OF WEATHER AND LIGHT FACTORS Russian patent published in 2023 - IPC G01N17/00 

FIELD: textile industry.

SUBSTANCE: invention is intended to assess the colour fastness of a textile material to the action of weather and light factors. Prepared samples of dyed textile material are fixed on the shielding surface of the stand. Samples are affected by natural light and weather factors due to exposure in the open air with simultaneous measurement, registration and integration of energy Q of total, direct and scattered solar radiation in MJ/m² received in the area of location of samples of coloured material. Kinetic dependence ΣQ=ƒ(t) of received radiation energy during the exposure time t is plotted. Periodically, after 1-3 months, spectrometric tests are carried out to change the colour of the dyed textile material relative to the standard in form of a sample not exposed to light-weather factors. To do this, a spectrophotometer operating in the CIE-Lab system measures the achromatic parameter L, the lightness of the colour, which determines the indicator D of the darkness of the colour and its change during weather exposure according to the dependence Di = 100^*-Li, where 100^* is the lightness of an ideal white colour. Percentage of maintaining the darkness of the colour of the sample k_D is calculated according to the formula k_D = 100% · D_i/D₀ = 100% · (100*-L_i)/(100* - L₀) where L₀ and L_i are initial and current lightness of colouring of samples, L₀=0^*+L₀, Li=0^*+Li, where 0^* is the lightness of ideal black colour; D₀ and D_i are the initial and the current darkening of the colour after exposure, D₀=100^*-L₀, Di=100^*-Li. Make up the kinetic dependence k_D=ƒ(t), which is used to judge the preservation of colour. Graphs are used to superimpose kinetic dependence k_D=ƒ(t) with kinetic dependence ΣQ=ƒ(t) of the radiation energy received during the exposure time t, placing the origin of coordinates and the current values of t at the same points and reflecting the relationship between the loss of darkness k_D and the amount of energy received ΣQ. Next the graph ΣQ=ƒ(t) is used to determine the exposure time point corresponding to the energy of total solar radiation in the area of the samples in the amount of 2500 MJ/m². The 2500 MJ/m² is projected onto graph k_D=ƒ(t) until intersection to determine the opacity retention coefficient k_D, which quantitatively characterizes the colour strength of the textile material against the action of light and weather factors.

EFFECT: reliability and objectivity of assessment of the colour strength of the textile material against the action of light and weather factors.

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