• Journal of Sericultural and Entomological Science
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• v.22 no.2
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• pp.22-23
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• 1981

The international raw silk grade classification method has been amended for several times since it has been created in 1932. S쳐h rather periodical changes have been raised as problems not because of it was created by scientifical research background or academical base but because of rather commercial aspect. This paper is, however, discussed by throughful academical aspect regardless raw silk sailers or buyers commercial interest. After carring a theoretical approach with thoroughful investigation on this matter, this paper happened to compare the current raw silk grade classification method against the developed theoretical silk grade classification method, which they happened to be much different each other. (omitted)

• Journal of Sericultural and Entomological Science
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• v.3
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• pp.61-67
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• 1963

This report is prepared to find how the filament of cocoon bave size deviation relates with the raw silk made by them which are intensively cultured in this country. Three recommended hybrid varieties and two varieties under working at Suwon Sericultural Experiment Station were selected as specimens. The cocoons were reeled as an individual filament of every fifty meters long skein with a wrap reel to weigh the denier and to investigate the relationship of the above statement so that it may be used for the quality estimation before processing it into raw silk. The conclusions obtained are as follows. (1) The variation of Pk${\times}$Sn was found as best cocoon for 21 denier raw silk use, but the number of cocoon to make the denier has to be eight which might cause more labor cost. (2) Baektoo-Kumkang and Myohiang-Chongchon were found as economical varieties for 21 denier use. (3) Seulak-Soyang is a proper variety for the use of 14 or 28 denier silk use. (4) Myohiang-Chongchon did not confirm a good property from the aspect of denier deviation. (5) It was found that there was a fairly strong corelationship between the mean cocoon bave size deviation as indicated by Ono's report. (6) Three graphs were prepared to estimate the cocoon quality before processing into various sizes of raw silk using the mean cocoon bave size and the raw silk size to be prepared. (7) Mean time, the graph which is able to estimate the expectable grade of the raw silk size deviation was designed for the practical use. (8) The expectable grade of the varieties used in this report were found as following data. Notice (A......cocoon number to make raw silk (B......total cocoon bave size deviation (C......expectable silk grade (9) The result of the work concerning the expectable denier deviation on 21 denier silk was the same with the statistical actual testing result as 1.25 D while the distribution showed farther necessity of improvement in technically.

• Textile Coloration and Finishing
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• v.22 no.4
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• pp.349-355
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• 2010

To investigate the half-degumming of raw silk, the degumming was carried out with soap or sodium carbonate or sodium bicarbonate and some mixed agents at $80^{\circ}C$ for 15 and 30 minutes. With soap of 20~25%o.w.f. degumming losses were about 7~12%. Degumming losses with sodium carbonate of 2~5%o.w.f. were about 6~15%. And about 6~12% wright losses were observed in the degumming with sodium bicarbonate of 20~30%o.w.f. In the degumming with the mixed degumming agents of soap and sodium carbonate, degumming losses were 9~15% with 5%o.w.f. soap and 2~5%o.w.f. sodium carbonate. Sodium carbonate was more effective on the removal of sericin from raw silk than soap. During drying generally half degummed silk yarns stuck together to result in harsh and hard lumps by the adhesion and solidification of the residue sericin of partially degummed silk. Sodium hydrosulfite in degumming agent effectively protected the adhesion of half degummed silk yarns.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.1
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• pp.19-24
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• 2014

Silk has always been one of the most favored textile materials. Fully degummed silk fiber (i.e., silk fibers without sericin) shows better luster than raw silk fiber (with sericin); it is also softer. On the other hand, raw silk fiber feels cooler because of the presence of sericin, making it useful as a textile for the summer season. Recently, partially degummed silk has attracted researchers' attention because it provides better luster, feel, and dyeing properties. However, the partial degumming of silk is very difficult because it results in inhomogeneously degummed fiber. In the present study, silk yarns were degummed with surfactant aqueous solutions and the effects of each surfactant on the degumming ratio, crystallinity, and homogeneity of the degummed silk yarn were examined. The degumming ratio and crystallinity index of silk yarn varied depending on the type of surfactant. On the whole, anionic surfactants resulted in higher degumming ratios and better homogeneity than nonionic surfactants.

• Journal of Sericultural and Entomological Science
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• v.46 no.1
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• pp.32-37
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• 2004

Gayageum and Geomungo are the traditional stringed music instrument in Korea. These strings are usually made of raw silk. This study was carried out to investigate the optimum condition for silk string producing method using several kind of silk and setting temperature of silk string. If the ply of strings and twisting condition were same, tenacity and elongation of every silk strings were similar, in spite of silk strings prepared by physically different raw silk. On the other hand, in setting treatment of twisted string, it was disclosed that the proper setting temperature of silk strings were 11$0^{\circ}C$ for 20 min.

• Journal of Sericultural and Entomological Science
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• v.17 no.1
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• pp.69-74
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• 1975

This report was aimed to examine the status of raw silk quality and to come up with means of the good quality silk production by use of the statistical quality control method. The results obtained are as follow ： 1) The raw silk quality of size 20/22 denier was found to be 2A grade during the last five years. 2) In order to level up the silk grade, the better quality control is required especially in the average evenness and cleanness. 3) It was found that winding brakes and elongation of silk threads have been versed gradually through the period. 4) Larger variation was observed in cleanness control chart, but low evenness have stayed with in the desirable control range.

• Journal of Sericultural and Entomological Science
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• v.7
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• pp.65-74
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• 1967

This work has been carried out to find the fundamental reasons of raw silk size nonuniformity by studying with the physical nature and its bave formation through the worm spinnerate with anatomical device. Mean time, the uniformity improving method is also attached to this paper after throughfall theoretical study. 1. According to the anatomical study of the silkworm spinnerate, the physical form decides the fiber cross section and also spinns more finner size as the spinning is continued collaborating with the muscle pressure and decrease of liquid silk in the silk gland. 2. The bave size deviation of the Korean cocoons have shown a little difference among the varieties, but, they are conclued as 0.58 denier in average which caused some size deviation of the raw silk inevitably. 3. The raw silk nonuniformity increases when the cocoon have size is not suitable with the proposed raw silk size. 4. The nonuniformity is also increased very much during the filature process in case of poor technical work, but even if we do our best, the best result is found as 30 percent improvement which is still worser than the natural cocoon size deviation. 5. It is required to be careful for the selection of silkworm variety in order to improve the nonuniformity of raw silk so that the bave size be suitable for the proposed silk. 6. The definite size silk reeling method could made better uniform silk, 20 percent at least, than the definite cocoon number silk reeling method. 7. A newly developed denier(21d) gauge was applied for the multiends type silk reeling machine which is widely used in Korea, and the result of the method showed 1.30 denier size deviation, but, in case of no use of it was 1.57 denier size deviation, that is, it could improve two grades more than the normal reeling method.

• Journal of Sericultural and Entomological Science
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• v.13 no.2
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• pp.155-160
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• 1971

This experiment was carried out to investigate the cocoon reeling condiditions required to technical balance work on the automatic silk reeling machine. The results obtained were as follows. 1) Reasonable reeling velocity with regard to raw silk yield and to reeling efficiency varied according to cocoon reelability. It was observed to be about 150m/min on good reelability cocoon (850m of nonbreaking bave length), about 120m/min on medium reelability cocoon (650m of nonbreaking bave length) and from 90m/min to 120m/min on bad reelability cocoon (500m of nonbreaking bave length) 2) Low temperature drying of cocoon (T$_3$) improved the reelability of cocoon, but increased the reeling accidance with deteriorating the quality of raw silk more than the control(T$_1$) or high temperature drying of cocoon (T$_2$). No significant difference was observed in its raw silk yield and silk by-product with regard to cocoon drying temperature. 3) Incomplete drying of cocoon (T$_3$) improved the reelability of cocoon, but increased the reeling accidance with deteriorating the quality of raw silk more than the control(T$_1$) or over drying of cocoon(T$_2$). No significant difference was observed in its raw silk yield and silk by-product with regard to cocoon drying degree. It was cocoon drying condition of cocoon was the control(T$_1$) or high temperature(T$_2$) rather than low temperature (T$_3$) in cocoon drying process. Control (T$_1$) or over drying of cocoon (T$_2$) was adequate rather than incomplete drying of cocoon (T$_3$) for the improvement of the quality of raw silk on the automatic silk reeling process. 4) It was found that the reasonable cooking condition of cocoon was optimum cooking with 4$0^{\circ}C$ of reeling temperature or incomplete cooking with 45$^{\circ}C$ of the reeling temperature in the automatic silk reeling of the domestic cocoon.

• International Journal of Industrial Entomology and Biomaterials
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• v.41 no.1
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• pp.1-5
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• 2020

Tumor necrosis factor-α (TNFα) is a representative marker for inflammation. Silk sericin is known as mild TNFα inducer. The purpose of this study was to compare the level of TNFα among different fractions of silk sericin. Silk sericin was extracted from cocoon and separated it by molecular weight. Each fraction was applied to RAW264.7 cells. The level of TNFα was evaluated by western blot and ELISA assay. In results, the level of TNFα was increased as time-dependent manner. Higher molecular weight fraction of sericin induced higher amount of TNFα than lower molecular weight fraction. In conclusion, different molecular weight fraction of sericin induced TNFα differently.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.74-78
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• 1986

The experiments were carried out to investigate the effect of humidity on the cocoon quality, and 4, 000 lots of cocoon pruduced fot five years in Chin yang, Ha dong, Keo chang, San chung of Kyeong nam, and Sun san, Sang ju, Young poong, An dong of Kyeong buk were analyzed. The results were summarized as follows ; 1. The reelability ration, the bave length, and raw silk ration were decreased with increasing the humidity in mounting time, and it was remarkably observed when the relative humidity was over 80%. 2. With increasing the reelability ration, the bave length, and raw silk ration were increased, and the longer the bave lenger the bave length was the higher raw silk ration obtained. 3. The average reelability ration for five years in autumn-rearing period was higher than that in spring-rearing period, but the bave length and raw silk ratio was on the contrary from the above. 4. The reelability ration of cocoon produced in the mountainous area was higher than that in the field area but the shorter the bave length, the raw silk ration had no significant difference between those.