To reveal the main factors involved in the development of the silk textile industry in developing countries, this study compared the industries of Laos and Nepal. In Laos, a private silk textile industry comprising sericulture, silk reeling, and silk weaving was launched in 1993 by a rural development program. The industry has thrived since then. In the 2000s, receiving a boost from government policy, it has become strategically important to poverty eradication and economic growth. The silk textile industry in Laos has thus ensured its security. In Nepal, in contrast, the government controlled the silk industry until 2009, focusing mainly on sericulture and silk reeling. But it accorded no importance to silk weaving for the development of the overall industry. There is no national policy on silk textiles, and the private sector has received little encouragement to develop the industry. These differences between Laos and Nepal reveal important factors involved in the development of the silk textile industry in developing countries.
We gamma-irradiated silk fibroin fibers at a dose of 25 kGy and measured the changes in their tensile properties and hue. Irradiation reduced both the breaking strength and the elongation at breakage by up to 10%, and yellowed the fibers, but the degree of crystallinity was almost unchanged.
We analyzed the characteristics of recent production in the silk weaving industry in Yonezawa following the Great East Japan Earthquake of 2011, and the management of successor companies, to support the revival of the industry. We interviewed representatives of the Yonezawa City Office, three weaving companies, and six successors. The fiber industry remains a local industry. The main silk products continue to be made, but shipments have been decreasing. The successors are trying to sell their silk products, but the earthquake has interrupted physical distribution and hindered the maintenance of looms. We suggest that the weaving cooperatives create a region-independent weaving production area, and that they urgently reestablish the loom repair system.
To define ways to revive the demand for Japanese clothing production, we interviewed representatives of nishijin weaving cooperatives and an obi weaving company. The demand for Japanese clothing, especially kimono and obi for women, decreased gradually from 1975 to 2011. Obi weavers have shifted to the small-scale production of a variety of items, and competition among them has become keen in recent years. We offer three ways to revitalize the Japanese clothing sector: to change the way of thinking about Japanese clothing from a commodity to artistic goods which are made with care and hard work; for weavers and traders to cooperate; and to strengthen sales promotion by nishijin weaving cooperatives.
During the Nara period, in the 8th century CE, demand for the high-class nishiki, aya, ra, and ryomen silks for government and religious purposes was small compared with the demand for general silks, but demand for kanhata was strong. Little high-class silk was given as diplomatic gifts to foreign countries. Some was used as ornamentation in inner Buddhist temples, and for monks’ costumes, sutras, and sutra bags. Kanhata was much used for making sutras, particularly in the latter half of the Nara period. Small amounts of nishiki, aya, ra, haku, and gauze silks were woven into ashiginu.
We analyzed the transformation to higher-value silk products after World War II from the aspects of product mix, price, and quality. Silk production shifted in favor of higher-value products until the 1970s, and the average price of silk products increased faster than commodity prices until then, but more slowly thereafter, with distinct volatility. The average silk yarn content of silk products decreased substantially during the 1970s, implying a decline in quality in terms of traditional criteria. The transformation to higher-value silk products was not necessarily accompanied by increases in price and quality, and some production areas could maintain price increases despite substantial volatility in average market prices.
To optimize a method for dissolving whole silkworm cocoon proteins, we pretreated cocoons with 70% ethanol and different concentrations of lithium bromide (LiBr) in solubilizing solution. Pretreatment with 70% ethanol improved the dissolution of the proteins in 9 M LiBr solution. LiBr solution at concentrations of 7.5 to 9.5 M buffered with 0.1 M Tris·HCl at pH 9.0 could dissolve whole proteins efficiently. The efficiency of dissolution was the same among different cocoons.