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SUPERVISOR
سیدمجید مرتضوی درچه (استاد راهنما) شادپور ملک پور (استاد راهنما) سیدمنصور بیدکی (استاد مشاور)
 
STUDENT
Mohammad Khajeh mehrizi
محمد خواجه مهریزی

FACULTY - DEPARTMENT

دانشکده مهندسی نساجی
DEGREE
Doctor of Philosophy (PhD)
YEAR
1385
Camouflage is usually used to disrupt an outline by merging it with the surroundings, making a target harder to spot, or to confuse an observer as to its nature. Some modern camouflage addresses visibility in the near infrared as well as visible light, for concealment from image intensification devices (night vision). Finding the best camouflage design for various environmental zones is one of the main problems in achieving the highest matching level between background and object. To reproduce a camouflage pattern on textile material for use as a covering substrate or a garment dyeing and printing techniques have been employed to apply special colorants to the substrate. Reflectance behavior of colorants in both visible (Vis) and near Infrared (NIR) regions of electromagnetic wavelengths are vital parameters that upon tuning in specific manner can guarantee a successful Vis-NIR camouflage on a textile substrate. In the present research, individual colors of a camouflage garment containing brown, olive green and khaki shades designed for use in desert zones of Iran was used as the reference and the objective of this research was defined in a way to find suitable colorants for matching the camouflage shades for camouflage in both visible and NIR regions. Cotton/Nylon fabric was used as the main substrate and printing technique was employed as the method for the application of camouflage colorants onto the substrate. Contrary to most documents recommending vat dyes for Vis-NIR camouflage on textiles, we found special pigments with much more suitability for this purpose. Additive was added to the standard pigment printing recipe to tune the reflectance level of each colorant in Vis-NIR regions. Additives including micro and nano TiO2 as opacifying agents and nano Carbon black (CB) and micro Carbon active (CA) as light absorbing agents with various concentrations were used in pigment printing formulations. Pigment Green B, Black P-NG, Brown R and Yellow FG were used for matching the camouflage colors where different concentrations of nano and micro TiO2 (0.25-1 g/kg) and CB (0.01-0.25 g/kg) and CA (0.15-0.50 g/kg) were added to each printing pastes. Printed formulae on cotton/nylon samples were dried in a laboratory stenter for 3 min at 100oc and were fixed for 5 min at 140oC. Finally, samples was washed by cold water and air dried. Reflective behavior of each sample was obtained using a UV-Vis-NIR reflectance spectrophotometer and wash, light, rubbing and perspiration fastnesses of each sample along with the air permeability and the contact angle of water with substrates surface were measured. From the reflectance graphs of brown, olive and khaki samples it was obtained that adding nano and micro TiO2 to the printing pastes could reduce reflectance value of all printed samples compared to the reflectance values of printed sample containing no TiO2. Light scattering capacity of TiO2 particles present in printed layer could lessen the amount of incident light penetrating into the layer decreasing the amount of light reaching the substrate itself to bounce back towards the detector lowering the total reflection level of TiO2 containing samples. TiO2 reflectance reducing role can be used as a tuning method to decrease reflectance value of pigment printed areas to match the desired Vis-NIR reference values in concentration range between 0.75-1 g/kg in pigment printing formulation. Particles of CB and CA could also be employed as additives to lower reflectance level of printed samples based on their light absorbing performance both in visible and NIR regions. Mie theory could be successfully used in order to justify the role of TiO2 particles in camouflage pigment printing procedures. Also, there is another probability that printed fabrics is opaque, so Mie theory couldn’t predict reflectance behavior of the samples.
صنایع نظامی در کشورهای مختلف از استتار البسه و تجهیزات نظامی جهت بالا بردن امنیت استفاده نموده اند. یکی از مسائل مهم در این ارتباط، یافتن طرح های استتاری مناسب برای مناطق زیست محیطی مختلف جهت ایجاد حداکثر هماهنگی میان زمینه و جسم می باشد. ابتدا نمودار انعکاسی فام های قهوه ای، سبز زیتونی و خاکی موجود در لباس های نظامی مناطق بیابانی ایران به دست آمد و با استفاده از رنگدانه های انتخابی نمونه های همانند با آنها تهیه گردید. همانندی مذکور میان نمونه ها و فامهای استتاری مرجع در دو ناحیه مرئی و مادون قرمز نزدیک (NIR) و با استفاده از روش چاپ پارچه با مخلوط رنگدانه ها به انجام رسید. نتایج حاصل از بررسی نمودارهای انعکاسی بدست آمده از نمونه های قهوه ای، سبز زیتونی و خاکی نشان می دهد که افزایش غلظت دی اکسید تیتانیوم در ابعاد نانو و میکرو به محتوای رنگدانه ای چاپ نمونه های فوق، باعث کاهش میزان انعکاس سطوح چاپ شده نسبت به نمونه چاپ شده فاقد دی اکسید تیتانیوم در نواحی Vis-NIRمی شود.

ارتقاء امنیت وب با وف بومی