Analysis Of The Aging Properties Of Plant Dyestuff And Its Dyed Fabrics

China has a long history.A large number of artifacts which show China's splendid ancient civilization,especially the dyed fabrics,have been found in succession since the early 20^th century.Many artifacts will age,fade and distort after unearthing,so the study of how to protect the ancient dyes and dyed fabrics from aging is significant.In order to provide basis and data for the protection of unearthed artifacts,this paper tested and characterized the aging behaviors of ancient dyes and dyed fabrics.The silk and flax fabrics were dyed by turmeric which is the representative botanical dye.The aging rules of the botanical dye and dyed fabrics were investigated and discussed through the accelerated aging tests.Aging samples of turmeric,dyed silk and flax fabrics were prepared after thermal,hygrothermal and ultraviolet aging tests.Their aging behaviors and mechanisms were discussed through the methods of spectrophotometry,infrared spectroscopy,scanning electron microscopy, and tensile property test.The results showed that:(1) The dye on the fabric decayed more seriously than dye powder under thermal and ultraviolet conditions,but the results were opposite under hygrothermal condition.(2) The curcumin which is the main component of turmeric decayed with time after aging.In the same time,the aging degree under hygrothermal condition was greater than that under thermal and ultraviolet conditions.(3) Dyed fabrics showed fading phenomenon after aging,and the fading extent under hygrothermal and ultraviolet conditions was more severe than that under thermal condition.Fiber surface was injured in different degrees.(4) The mechanical properties of silk and flax fabrics decreased after aging,and the descending speed of mechanical properties of silk fabrics was faster than that of flax fabrics under all aging conditions.In order to guarantee that the experiment will carry on smoothly,an ultraviolet aging device was designed.The prominent peak position of the ultraviolet lamp is at 340nm.Temperature precision is±0.5℃,and humidity precision is±5%RH.This device can satisfy thermal,humid and ultraviolet aging tests.