Research On Influence Of Ancient Silk's Tint And Trait Under Physical Action

The main purpose of this dissertation is to research on the aging influence of silk textile cultural relic under physical action, to seek after environmental parameters of protecting silk textile cultural relic through experimental study. This dissertation studies the trait of silk textile cultural relic and protection technique of silk textile cultural relic, and research change of tint and character of silk textile cultural relic under temperature, humidity and light irradiation action through indexing documents, collate and summarize on existing research findings. The emphasis is study change law of silk's tint under visible light exposure action through simulation aging experiment. A sort of textile light ageing laboratory apparatus is invented for progress correlative experimental investigation. Using the laboratory apparatus take out ten narrow ranges from visible light to process illumination aging experiment for recent silkworm silk textile. The change complexion of silk's tint and character is researched under each narrow ranges visible light irradiation. The dissertation also research the change complexion of silk's tint and character under flash lamp light irradiation through aging experiment of flash lamp irradiation recent silkworm silk textile, and explore some methods to avoid damage of flash lamp light irradiation for silk textile cultural relic. The optimal physical environment parameter of exhibiting and preservation of silk textile cultural relic is obtained through systematic study of physical environment procreant influence for silk textile. The stress research content of this dissertation is light irradiation environment of exhibiting and preservation of silk textile cultural relic. The brief and content of this thesis are introduced as following:1. We invented a kind of light ageing experimental equipment that can be used for textile light ageing experiment with sub wave bands in visible light bands.It is very difficult all the while that find a way into textile light ageing experiment in visible light bands, especially, because there isn't appropriate experimental conditions, furthermore, the light ageing experiment in visible light bands needs great effort and time, and the effect of visible light ageing experiment is very ill defined, so that, we can not find a way into light ageing experiment with sub wave bands in visible light bands. Now, we make use of visible light narrow-band filter take out narrow-band visible light lamp-house from continuous spectrum of ordinary incandescent lamp, and use the narrow band lamp-house doing light ageing experiment of textiles, the experiment of sub wave bands light ageing in visible light bands can come true finally. If only narrow-band filter required bands is made according to experimental demand, we can obtain the narrow-band lamp house in visible light bands, then we can use the narrow-band lamp house find a way into the experiment of sub wave bands light ageing in visible light bands for textile materials. The experiment indicate some bands where the effect of light ageing is inconspicuous for tint silk surface, the experiment indicate tint ageing situations of different bands visible light action for tint silk surface too, it provides some reference for making and selecting lamp house in textile museum.2. The humidity is an important source that change silk's tint, the vegetable dyeing silk discolor easily in wet state, and the color fading of different color silk is different.A lot of experiment makes sure the tint of the vegetable dyeing silk is very stabilization when the relative humidity is within 20%～40%. Every color silk all have heavy color fading when the relative humidity preponderates over 60%. In the higher humidity condition, white silk appear yellowing, light color silk appear darkening, deep color silk appear brighten, the brilliance of silk fabric is reduced and the color is changed to murky gray. However, the over dried condition can make silk fabric season crack and embattlement, therefore, the best relative humidity condition of preserving color silk cultural relic is within 55%～60%.Every color silk culture relic has itself color hold facility in same wet condition. The blue silk, white silk and black silk have rather strong color hold facility, so they color approach actual when them come up out of land. The red silk, yellow silk and brown silk have rather weak color hold facility, so they color away from actual when them come up out of land.The frequency changing humidity can bring frequency expand and shrink of silk fiber, and destroy silk fiber texture, and reduce silk fiber strength, and bring silk fiber rupture, and conduce silk textile damage. Therefore, the humidity in museum room must change slowly; the relative humidity changing within one day must less than 5%.This dissertation research wet condition creative affect for silk textile aging through hydrolyze aging experiment of vegetable dyeing mulberry silk cloth. The changing rule of dyeing silk's color is discovered through analysis experiment of the vegetable dyeing mulberry silk long-term immersion in deionized water. The experimental result can serve as reference for determining preserving environmental parameter of color silk textile relic. 3. The key factors of silk and silk's color aging effect under visible light irradiation are illumination, irradiation time, energy destroy of short-wavelength light and heating destroy of long wavelength light.3.1 There are several wave bands in visible light that cause faintish aging affect on silk's surface.The different wavelengths visible light cause different aging effect on silk's surface when light irradiation keeps same environmental condition. There are different wave bands that cause faintish aging affect on silk's surface for different color silk cloth.3.2 The ambient temperature and humidity have some effect for irradiate aging of silk's surface color.The status of silk's surface irradiate aging not only relate with light intensity, light wavelength and illumination time but also relate with ambient temperature and humidity. The temperature brings speedup action for silk's surface irradiate aging, the color difference of silk's surface there will be a certain extent enlargement along with temperature rise. 3.3 The intensity of light source cause very important effect for silk cloth color aging.There is relatively large color difference when the luminance is relatively large; the longer wavelengths light cause relatively severe aging due to heating action of longer wavelengths light induce tint change of dye and silk. There is relatively small color difference when the luminance is relatively small; the main aging effect is energy destroy of short-wavelength light. The effect that short-wavelength light produce color difference for every colors sample is greater than the effect of long-wavelength light when light irradiation keeps same environmental condition.3.4 The status of silk's surface irradiate aging relate with light wavelength directly.The silk's surface aging phenomenon that different wavelength light cause is differ, the different color silk's aging effect that same wavelength light cause is differ also, they have different aging mechanism of action. The heating action of longer wavelengths light results in silk fiber dryness, thin down and character decline. The energy action of short-wavelength light results in silk fiber surface shatter.3.5 The main factors of influence light irradiation aging effect include silk's color, dye particles on silk's surface and defects on silk's surface.The color difference of some color silk sample in visible light struck aging experiment relate with color kind, dye particles distribution on silk's surface, tuft and pollutants impurity on silk's surface. The light irradiation result in dye particles distribution, tuft and pollutants impurity change color and carbonization, and form itself into point of decalescence, and transfer heat to silk fiber farther destroy silk fiber. The visible light action on dye particles can cause its color change thereby cause silk color change.3.6 The destructive effect of light irradiation for silk's color and character relate with many factors.The factors of influence silk light irradiation sensitivity include silk's color kind, dye's character, dye mordant and light reflecting characteristics of silk's surface. In this research experiment, the yellow silk sample, brown silk sample and red silk sample discolor easily under light irradiation action; the light aging action of white silk sample is least. The light irradiation has greater destructive for silk fiber of black silk sample, red silk sample and brown silk sample.3.7 The infrared ray in flash lamp light is main destructive factor for silk cloth under flash lamp light irradiation action.The heating action of infrared ray in flashlight spectrum is main factor that can cause white silk turn yellow and dye silk discolors, it also is arch criminal that destroy silk fiber.The experiment finds color aging causations of six kinds silk sample under flash lamp light irradiation, and finds factors of influence silk's surface light aging that include spectral component of flashlight, silk's surfacing, dye particle, tuft, dirt particle and silk's color. This dissertation also brings forward some measures to avoid damage of flash lamp light irradiation.4. The light irradiation environment of silk cultural relic4.1 The illumination control of exhibiting environment of silk cultural relicThe ambient light illumination should be within 30～501ux in exhibition region of silk cultural relic. The ultraviolet relative content of illuminated light sources should be less than 75μW/lumen in exhibition region of silk cultural relic.4.2 The light irradiation control of silk relicThe illumination of silk cultural relic surface should be less than 501ux, and the amount of exposure should be less than 150000lux·h per year. The exhibition region of silk cultural relic should be used infrared sensing device to control switch of illumination lamp and avoid often-open illumination system. The uniformity ratio of illumination should be less than 0.7 on cultural relic exhibition surface. The uniformity of illumination should be less than 0.5 between borders upon region.4.3 Avoid light ray direct projection on culture relic surface The incidence angle of light ray should be larger than 45 degree. This incidence angle is propitious to protection cultural relic as well as propitious viewer sight.