• Macromolecular Research
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• 제17권6호
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• pp.378-387
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• 2009

This research compared three methods for producing and processing nanocomposite polypropylene filament yarns with permanent antimicrobial efficiency. The three methods used to mix antimicrobial agents based on silver nano particles with PP were as follows: 1) mixing of PP powder and inorganic nanocomposite filler with the appropriate concentration using a twin-screw extruder and preparing granules, 2) method 1 with a singlerather than twin-screw extruder, and 3) producing the masterbatch by a twin-screw extruder and blending it with PP in the melt spinning process. All pure polypropylene samples and other combined samples had an acceptable spinnability at the spinning temperature of $240^{\circ}C$ and take-up speed of 2,000 m/min. After producing as-spun filament yarns by a pilot plant, melt spinning machine, the samples were drawn, textured and finally weft knitted. The physical and structural properties (e.g., linear density, tenacity, breaking elongation, initial modulus, rupture work, shrinkage and crystallinity) of the as-spun and drawn yarns with constant and variable draw ratios (the variable draw ratio was used to gain a constant breaking elongation of 50%) were investigated and compared, while DSC, SEM and FTIR techniques were used to characterize the samples. Finally, the antibacterial efficiency of the knitted samples was evaluated. The experimental results revealed that the crystallinity reduction of the as-spun yarn obtained from method 1 (5%) was more than that of method 2 (3%), while the crystallinity of the modified as-spun yarns obtained with method 3 remained unchanged compared to pure yarn. However, the drawing procedure compensated for this difference. By applying methods 2 and 3, the drawing generally improved the tenacity and modulus of the modified fibers, whereas method 1 degraded the constant draw ratio. Although the biostatic efficiency of the nanocomposite yarns was excellent with all three methods, the modified fabrics obtained from methods 1 and 2 showed a higher bioactivity.

• 한국염색가공학회지
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• 제35권3호
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• pp.169-178
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• 2023

The extended use of polyester nowadays has increased the amount of waste polyester (PET) released into the environment. Although these materials don't directly harm living things or the ecosystem, their inability to biodegrade remains one of the major global threats, driving up the amount of solid waste made up of PET. Environmental concerns have approved an increasing interest in recycled PET however the production of recycled PET with sufficient mechanical properties is still a challenge. Recycled Polyester (rPET) yarns are inexpensive and have the potential to acquire better mechanical characteristics through physical treatments, particularly by using technically simple method like uniaxial drawing. This study inspected the drawn behavior of virgin PET yarns and rPET yarns under various drawing parameters by first analyzing the initial material characteristics of both yarn. The impact of stretching on mechanical and morphological properties was also investigated. The results showed that virgin PET has better properties than rPET yarn; however, mechanical properties resembling virgin PET are achieved after optimizing the draw ratio.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2001년도 가을 학술발표회 논문집
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• pp.83-86
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• 2001

Seed coat fragments (SCF's) are small portions of seed coat that have been broken from the cotton seeds during ginning, a mechanical process that separates the cotton lint from the seed： Seed coat fragments have drawn attention because they are one of the major imperfections that affect the appearance and quality of cotton yarn and fabrics [1,2]. (omitted)

• 한국염색가공학회지
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• 제9권4호
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• pp.7-19
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• 1997

The purpose of the study was to investigate the shrinkage and creep behavior of PET filaments which were prepared at various spinning speeds(3,300, 4,000, 5,000, 6,000, and 7,000m/min) and anneal($120^{\circ}$, 30min & $150^{\circ}$, 40min). In order to determine the shrinkage and creep behavior with the crystallinity change, PET filaments were treated with low(12$0^{\circ}C$, 30min) and high($150^{\circ}$, 40min) temperature conditions with hot air dryer under the constant tension. The results of the study were as follows: as the spinning speed increased, the degree of shrinkage and elongation of the sample treated by wet condition decreased. The sample with 0.01g/d of load under various spinning speeds showed shrinkage behavior and highest shrinkage ratio at $76^{\circ}$ which was Tg of PET. The degree of shrinkage and elongation of the treated sample was less than those of the untreated sample by wet treatment. Especially, there was less degree of shrinkage and elongation of the sample treated by higher temperature condition. In 3,300m/min of spinning speed the draw ratio of undrawn yarn of a mixture of a-axis orientation and c-axis orientation was 2.0, which is similar to the value of the traditional drawn yarn. Finally, there was a big range of shrinkage and elongation by wet treatment in 3,300 m/min of spinning speed.

• Composites Research
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• 제12권2호
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• pp.91-100
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• 1999

고상공정법(SSP)에 의한 고강도폴리에틸렌(HSPE) 섬유의 제조는 초고분자량 폴리에틸렌 분말의 압출과 연신으로 용매를 사용하지 않고 제조된다. 고상공정으로 제조된 고강도 PE 테이프사의 특성을 분석한 결과, 고강도 PE 테이프사는 여신비의 증가에 따라 인장강도가 증가하였고, 파단면에서 fibril 분리현상이 많이 생겼다. 고강도 PE 테이프사의 표면을 산소플리즈마로 처리하여, 표면에너지를 측정하였고, 수지와 계면결합력을 분석한 결과, 100W와 5분간의 플라즈마 처리에서 가장 높은 계면결합력을 나타내었다. 고강도 PE 테이프사 강화복합재료의 물성을 겔방사법으로 제조된 고강도 PE 섬유강화 복합재료의 물성과 비교하여 고찰하였다.

• 복식문화연구
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• 제16권3호
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• pp.425-431
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• 2008

The purpose of this study was to observe the changes of skirt length of knitted flare skirts when the seamless test garments were made which had been having full shape while being knitted and to change and amend the challenges in advance when those were knitted. For this study, I made 6 kinds of knitted test garments of wool 100% yarn with seamless knitting machine, which differed from each other by skirt angles ($90^{\circ},\;180^{\circ}$) and gauges (7G, 12G, 15G), and then I measured deflection changes of their length for 2 weeks. Findings and conclusions drawn from this study were as follows: First, the side seam line of full shape hecame somewhat longer than center. Second, 7G and $180^{\circ}$ knitted flare skirt showed the biggest length deflection changes. Third, there was no difference at rear waist deflection changes between front pattern and rear. Fourth, it was difficult to control the tensions of right and left strings as to the knitting directions.