Photodegradation of the Holly Kaaba Cover Fabric by the Environmental Conditions in Mekka

Khaled Ebrahim Elnagar, Ferial Mahmoud Tera


Samples of the holly Kaaba jacquard silk cover fabric were exposed directly to the prevailing environmental conditions at Mekka city in the Kingdom of Saudi Arabia (KSA) through whole one year and at different successive periods. Thus the incident solar energy (ISE) values and the accompanied amount of UV radiation were evaluated for the whole exposure periods, together with average maximum temperature and relative humidity values, and also, the total amount of sunny hours. The produced photophading was assessed by following the changes in the physical and mechanical properties. Thus, losses of tensile strength and elongation percent, together with the change in drape, stiffness, weight/cm2 and the thickness were assessed and discussed. Moreover, the change in the colour parameters: brightness (L), red-green component (a), yellow-blue component (b) and all over colour change (∆E), and colour strength expressed as (k/s) besides the light fastness ratings were also examined. It was concluded that, the prevailing severe environmental conditions together with the air pollution at that urban site had contributed greatly to the observed degradation of all the examined properties of the holly Kaaba silk cover fabric. Maximum loss was observed at summer time and during the pilgrim period.

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