• 한국산업보건학회지
• /
• 제15권3호
• /
• pp.221-231
• /
• 2005

In this study, occupational exposures to man-made mineral fibers (MMMFs) including glass wool, rock wool, and continuous glass filament fibers were determined and evaluated on the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV). A total of 171 personal samples collected from 4 glass wool fiber, 2 rock wool fibers, 4 continuous filament glass fiber products manufacturing and a glass fiber and rock wool insulations using industries, and determined respirable fibers concentrations using the National Institute for Occupational Safety and Health (NIOSH) Method 7400, "B counting rule. The fiber concentrations of samples from workers installing thermal insulations in a MMMF using industry showed the highest value: geometric mean (GM) = 0.73 f/cc and maximum = 2.9 f/cc, 70% of them were above the TLV, 1 f/cc. Workers' exposure level (GM= 0.032 f/cc) in the rock wool manufacturing industries was significantly higher than those of glass wool (GM=0.012 f/cc) and continuous filament glass fibers (GM=0.010 f/cc) manufacturing industries (p<0.01). No samples were more than the TLV in the MMMF manufacturing industries. There was a significant difference among companies in airborne fiber levels.

• Composites Research
• /
• 제19권6호
• /
• pp.32-37
• /
• 2006

본 논문은 두 가지 암석인 국내 광물로부터 무기질 연속섬유 제조과정을 요약한 것이다. 두 가지 광물인 현무암과 맥반석으로부터 용융 방법으로 연속섬유를 생산하였다. 제조방법은 유리화된 재료를 노즐이 하나인 백금과 로듐 합금 도가니인 부싱에 넣어 섬유방사가 가능한 온도로 가열하였다. 유리화된 현무암은 어떤 첨가물도 없이 연속섬유 제작에 적합하였으나 맥반석은 산화붕소의 첨가가 연속섬유 방사를 가능하도록 하였다.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1998년도 봄 학술발표회 논문집
• /
• pp.111-115
• /
• 1998

Fiber spinning is a continuous deformation process by which material is converted into a fiber. The melt spinning process was analyzed mainly by employing an asymptotic method of the so-called thin filament equations which formulates dynamics of spinning process by averaging over the cross-section of filament the set of fundamental equations. The method gives the approximate results for commonly used circular fiber spinning.(omitted)

• Composites Research
• /
• 제23권3호
• /
• pp.43-49
• /
• 2010

제주도 표선리 현무암 원광을 이용하여 연속 방사에 의해 현무암 섬유를 제조하였다. 먼저 현무암의 용융특성을 확인하기 위하여 현무암 원광을 백금도가니에 넣고 $1550^{\circ}C$로 용융시킨 후, 물속에서 급냉하였다. 냉각한 후 X-선 회절, 열팽창, 고온 점도, 고온 전기전도도와 고온 현미경을 측정 분석하여 연속방사 조건을 조사하였다. 연속 섬유를 제조하기 위한 최적의 방사 온도와 고온 점도는 각각 $1264^{\circ}C$와 $10^{2.8}$ poise이었다. 제조된 방사 섬유의 특성은 인장강도, 전자현미경 관찰, 내열시험 등으로 확인하였다. 부싱 온도 $1240^{\circ}C$와 와인더 속도 4600rpm의 방사 조건에서 제조된 섬유의 인장 강도는 3660MPa을 나타내었다.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2000년도 추계학술발표대회 논문집
• /
• pp.203-207
• /
• 2000

Filament Winding Process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And now well established as a versatile method for storage tanks and pipe for the chemical and other industries . In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture , The results obtained from experiments were compared with the theoretical values obtained by the rule of mixtures. And the purpose of this paper is the suggestion of an appropriate test method for the evaluation of tensile properties of filament wound structures .The tensile strength of a ring specimen tested by the dress disk test showed better agreement with the theoretical values than of a ring specimen tested by the split disk test because the stress concentration in edges of a split disk test fixture is more severe than that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권2호
• /
• pp.139-145
• /
• 1998

Filament winding method is widely used for composite fabrications using low viscosity liquid for-mation and processing asymmetrical structures of pressure vessel pipe rocket motor case etc. The filament winding method is affected by several parameters such as pot life of process time viscosi-ty of resin filament winding temperature and schedules curing condition and post curing condi-tion of resin. To develope high functional composite materials the rotation(5, 15, 20, 30rpm) of the winding machine was controlled by D.C motor. And the wiper to give proper tension was equipped between strand and resin bath. The resin is hooked by the design wiper. The adequate cure schedule was found by DSC. NOL ring test is carried out to investigate the basic physical properties such as design technology. The void contents in filament winding is generally higher than that of the prepreg laminated plate. These high contents of void can make a crack in resin in spite of low deformation. These problem was solved by giving tension in processing. To improve the characteristics of fiber volume fraction void contents resin/fiber bonding the winding speedc is changed under constant tension. It was found that resin impregnation was not different from in fiber contents void contents at the range of 0.5~1kg tension but it was found that resin was not impregnated at the above of 1.5kg tension. In burst test a pure PE liner was failed at a nozzle part under the $14kg/\textrm{cm}^2$ pressure but a pressure vessel of CNG was failed at a cylinder part under the $200kg/\textrm{cm}^2$ pressure.

• 한국산업보건학회지
• /
• 제15권3호
• /
• pp.213-220
• /
• 2005

Penetration and health effect of fibers was related with their diameters and length. The purpose of this study is to characterize and compare the diameter and length of airborne man-made mineral fibers(MMMF) or synthetic vitreous fibers in the related industries. The average fiber length of the continuous filament glass, rock wool, refractory ceramic, and glass wool fibers production industries approximately 27, 28, 35, $50-105{\mu}m$. Airborne glass fibers were longest in all the type of MMMFs. The average diameters of airborne fibers generated from refractory ceramic, rock wool, glass wool, continuous filament glass fibers production industries were approximately 1.0, 1.6, 1.5-4 and $10{\mu}m$, respectively. The percentages of respirable fibers(<$3{\mu}m$) were 94% for RCFs, 73% for rock wool fibers, 61.0% for glass fibers, and 1.6% for filament glass fibers. The length of glass fibers were the longest in all types of fibers, and length of the others were similar. The refractory ceramic fibers were smallest in diameters and highest in fraction of respirable fibers.

• Journal of Advanced Marine Engineering and Technology
• /
• 제25권1호
• /
• pp.87-94
• /
• 2001

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And now it is well established as a versatile method for storage tanks and pipe for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture. The results obtained from experiments were compared with the theoretical values obtained by the rule of mixture. And the purpose of this paper is to suggest an appropriate test method for the evaluation of tensile properties of filament wound structures. The tensile strength of a ring specimens tested by the dress disk test showed better agreement with the theoretical values than of a ring specimen tested by the split disk test because the stress concentration in edges of s split disk test fixture is more severe than the that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
• /
• pp.15-20
• /
• 2000

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And it is now well established as a versatile method for storage tanks and pipe for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture. The results obtained from experiments were compared with the theoretical values obtained by the rule of mixtures in composites . And the purpose of this paper is the suggestion of an appropriate test method for the evaluation of tensile properties of filament wound structures. The tensile strength of a ring specimen tested by the dress disk test showed better agreement with the theoretical values than that of a ring specimen tested by the split disk test because the stress concentration in edges of a split disk test fixture is more severe than that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제21권1호
• /
• pp.145-150
• /
• 2010

The regenerated silk fibroin with various molecular weights (MW) was prepared by different dissolution condition and the effect of coagulant on the wet spinnability of the various MW silk fibroin solutions dissolved in formic acid was investigated by the observation of wet spun filament in coagulant and the measurement of maximum draw ratio. The observation on the wet spun filament in coagulation bath revealed that good fibers without bead were formed in a high MW and a very high MW silk fibroin samples. In contrast, beads were observed in the silk fibroin sample with medium MW. The maximum draw ratio of wet spun silk fibroin filament decreased with MW reduction. The decrease of maximum draw ratio in isopropanol, acetone, DMF and THF was remarkably higher than that in methanol and ethanol, indicating that the coagulant type strongly influenced the wet spinnability. The two simple evaluation methods used in this study showed complementary information for wet spinnability: (a) The observation of filament in coagulant was effective to check a continuous fiber formation and a bead formation, and (b) the maximum draw ratio measurement was useful to examine the post drawing ability related to molecular orientation.