Comfort characteristics of fabrics made of compact yarns

Comfort is one of the most important aspects of clothing. Thermal comfort is related to fabric’s ability to maintain skin temperature and allow transfer of perspiration produced from the body. Properties like thermal resistance, air permeability, water vapor permeability, and liquid water permeability are suggested as critical for thermal comfort of clothed body. In this study the fabrics developed from the EliTe compact yarns are compared with the fabrics made from normal yarns. The thickness of the fabrics made from EliTe® compact yarns is also slightly less than the fabrics made from normal yarns. Fabrics made from EliTe® compact yarns have shown greater air permeability as compared to the fabrics made from normal yarns. It is observed that, thermal resistivity values of the fabrics developed from EliTe® compact yarns are lower than the fabrics made from normal yarns indicating they are cooler fabrics compared to normal fabrics. Fabrics developed from the EliTe® compact yarns have shown slightly higher values of MVTR (moisture vapor transmission rate) as compared to the fabrics made from the normal yarns. The wicking characteristic of fabrics developed from EliTe® compact yarns was slightly higher than the fabrics developed from normal yarns.     

Bending behavior of coated yarns

Cotton yarns were coated with a polymer solution to hold surface fibers to the yarn body, which caused fiber-fly generation during knitting process. The physical property of the coated yarn, especially a bending rigidity was investigated in order to evaluate the performance of the coated yarn during knitting. SEM images showing the surface condition of the coated yarn demonstrated that the thickness of a coating material increased as the concentration of the coating solution increased. The results of the bending rigidity measured using KES-FB2 system showed that the bending rigidity of the coated yarn increased as the concentration of the coating solution increased. The results also revealed the possibility that yarn coated with a low amount of coating material should be employed for further research of reducing fiber-fly generation during knitting process.     

Study on splicing performance of different types of staple yarns

The present paper reports the detailed study on the splicing behavior of viscose staple fiber yarns made from ring, rotor, friction and air-jet spinning technologies. The linear density of all the yearns was kept constant at 29.5 tex. The splicing parameters like splicing pressure and duration of the splicing were taken as variables. Three levels of splicing pressure at constant splicing duration and three levels of splicing durations at constant splicing pressure were considered. Splices were introduced at all these levels for the four different technologies. These splices were tested for their tensile properties and the properties of splices were evaluated in terms of retained splice strength (RSS) and splice break ratio (SBR). The splice photographs were taken and splices were analyzed for their structure and for diameter profile along the length of the splice.     

不同氮水平下杂交油菜的矿质营养研究

１９９４年和１９９５年在田间不同施氮水平条件下,对杂交油菜品种黄杂１号和秦油２号氮、磷、钾、钙、镁、铁、锌和锰的吸收、积累和分布进行了研究。结果指出,不同施氮水平条件下随生育期进展植株氮、磷、钾浓度的变化均表现为由高到低趋势。不同生育期植株氮、钾浓度和生育前期的植株磷浓度随施氮量的增加而增加,生育后期的植株磷浓度却随施氮量的增加表现为降低趋势。在生育后期植株各器官的氮、磷养份向籽粒的迁移性较强,而钾的迁移性则相对稳定。钙在果壳的浓度最高,在主茎和果中所占的比例最大,而在种子中的浓度和所占比例最小。铁在根系中的浓度和所占比例最大,而种子的浓度和所占比例最小;镁、锌和锰均是在种子中的浓度和所占比例最大。     

Effects of twisting parameters on characteristics of rotor-spun composite yarns with spandex

Spandex fibers have superior stretch and elastic recovery ability. Composite yarns containing spandex are frequently used to manufacture elastic textile products and accessories. We have developed a composite yarn spinning system that produces different kinds of composite yarns containing spandex on a modified open-end rotor spinning frame. By changing the twisting parameter of composite yarns, we studied the structure and properties of rotor-spun composite yarns with spandex. The results indicate that the twisting parameter has great influence on the structure and properties of rotor-spun composite yarns with spandex. The linear density of spandex filament has influence on the properties of composite yarns too. In comparison with normal rotor-spun yarn, the appearance of composite yarns is clearer, the structure is much tighter, and the properties are improved.     

Comparative study on the characteristics of knitted fabrics made of vortex-spun viscose yarns

Murata vortex spinning system is based on the air jet spinning system. The vast majority of previous works deal with the properties of vortex spun (VS) yarn and the spinning system. In this study, we investigated knitted fabrics from VS yarn in comparison with fabrics from ring (RS), compact (CS) and open-end rotor (OES) spun yarns made from viscose. The effect of yarn spinning system on dimensional and physical properties of knitted fabrics was explained with specific attention to fabrics from VS yarn. Shrinkage of fabrics from VS yarn has the lowest at widthwise direction, while having the highest at lengthwise direction. It is shown that the order of fabric spirality and twist liveliness for yarns from different spinning systems are quite similar. However, relation between loop shape factor and angle of spirality is inconsistent. Angle of spirality of fabrics from VS yarn is higher than fabrics from OES yarn, but lower than that of others. The bursting strength of fabrics from VS yarn is lower than that of those from RS and CS yarns and higher than that of those from OES yarn. From this study, it is also evident that fabrics from VS yarn have the lowest pilling tendency and highest resistance to abrasion.     

Preparation and characterization of melt-spun PVC filament yarns

Polyvinyl chloride (PVC) fibers were melt-spun to prepare mono and multifilament yarns. To find optimum spinning and drawing conditions, various parameters such as spinning temperature, spinneret diameter, drawing temperature, and drawing ratio were examined. From the observation of the spinnability under various conditions, we found that the optimum conditions were as following: the extrusion temperature and die temperature were 175–180°C and 185–190°C, and the drawing temperature and drawing ratio were 85–95°C and 3.4, respectively. Under these conditions, the spinneret diameter could be reduced to the minimum value, 0.5 mm. Spun PVC filament yarns were subjected to the different yarn texturing process of stuffing box and pin false-twist method. The PVC yarn fabric was prepared by the knitting of textured yarns. Finally, the anion-emission and antibiotic properties of the knitted PVC fabrics were precisely evaluated.     

Effects of bleaching and dyeing on the quality of alpaca tops and yarns

This paper reports the effects of bleaching of alpaca tops and dyeing of bleached alpaca tops/yarns on the quality of tops and yarns. A dark brown alpaca top was bleached with hydrogen peroxide. Two bleaching methods were tried for effectiveness of color removal. A portion of each bleached top was dyed after bleaching. Color parameters were examined for unbleached, bleached and bleached/dyed tops, these tops were then converted into yarns of different twist levels and counts using a worsted spinning system. Some of the bleached yarn from each bleaching method was dyed in a package dye vat to compare the difference of top dyeing versus yarn package dyeing on yarn quality. Fiber diameter, yarn strength, yarn evenness, yarn hairiness and fiber degradation were tested to examine the effects of bleaching and dyeing on these properties at top and yarn stages. A processing route for bleaching and dyeing alpaca fiber was recommended.     

A theoretical investigation on the generation of strength in staple yarns

In this article, an attempt has been made to explain the failure mechanism of spun yarns. The mechanism includes the aspects of generation and distribution of forces on a fibre under the tensile loading of a yarn, the free body diagram of forces, the conditions for gripping and slipping of a fibre, and the initiation, propagation, and ultimate yarn rupture in its weakest link. A simple mathematical model for the tenacity of spun yarns has been proposed. The model is based on the translation of fibre bundle tenacity into the yarn tenacity.     

Theoretic analysis on the manufacture of blended yarn by one spinneret

The possibility of producing blended yarn by using one spinneret is analyzed theoretically, especially the formation of differences in linear density and shrinkage between the monofils. Under the same spinning pressure, the die-spinning nozzles with different diameters are used to produce the differences in the flow of the melt. According to the hagen-poseuille equation for streamline flow in cylinder pipe, the volumetric flow rate and the mean melt speed of die-spinning nozzles increase with the increase of diameters. Under the conditions that the winding speeds are the same, so that the effective draw ratios decrease with the increase of the die-spinning nozzles diameters. Then, the filament formed through the die-spinning nozzle with large diameter is coarse and have a low birefringence. On the contrary, the filament formed through the die-spinning nozzle with small diameter is fine and have a high birefringence. The differences between the filament in structure and property could be acquired by one spinneret.     

不同玉米杂交种抗旱性比较研究

利用生产上应用的32个常规玉米品种,在可移动防雨棚内进行玉米抗旱性比较试验。试验设干旱胁迫(全生育期内灌水量100 mm)和正常灌水(灌水量300 mm)两种处理,测定雌雄开花间隔时间(ASI)、卷叶度(LRI)、离体叶片失水速率(RWL)等与玉米抗旱性有关的11个鉴定指标。结果表明,筛选出与抗旱性显著相关的鉴定指标9个,采用模糊隶属函数法对这9个鉴定指标和7个抗旱指标进行综合性评价,最终筛选出8个抗旱品种和19个较抗旱品种。     

Lodging-related morphological traits of hybrid rice in a tropical irrigated ecosystem

Hybrid rice (Oryza sativa L.) has been proven to be effective in increasing yield potential, but lodging often limits its yield in high-yielding environments. This study was conducted to determine genotypic variation in lodging resistance and lodging-related morphological traits among hybrid and non-hybrid check varieties, and to identify the key morphological traits associated with lodging resistance. Lodging behavior of 16 rice genotypes, including 12 hybrids and four inbreds, was studied at the International Rice Research Institute farm during the 2004 wet season (WS) and 2005 dry season (DS). Grain yield and visual score of lodging were determined at maturity. Lodging-related morphological traits were measured at 30 days after flowering. Large genotypic differences in lodging-related morphological traits were observed. Among these traits, dry weight per unit length, breaking resistance, and lodging index (bending moment/breaking resistance × 100) of lower internodes were significantly correlated with visual score of lodging. Several hybrids demonstrated high lodging resistance although their average plant height was over 120 cm. The lodging-related morphological traits and visual score of lodging in these hybrids were comparable with those of the non-hybrid check varieties with strong lodging resistance. These results suggest that increases in dry weight per unit length and breaking resistance of lower internodes are primary targets for reducing lodging index, thus improving overall lodging resistance of hybrid rice in a breeding program.     

Study on characteristics of compact yarns under dynamic state

The dynamic testing conditions simulate actual manufacturing conditions more closely than static testing. In most cases, as results from dynamic tests differ significantly from static tests, dynamic tests are more relevant from the point of view of processing of yarn. The yarns are in motion when they are running on different machines during the production process viz. weaving; knitting etc. Compact ring spun yarns have created a fundamental change how the industry views the ring spinning. The new technology compact yarns such as EliTe® yarns need to be compared with the normal doubled yarns in a dynamic way. This study involves dynamic testing of the EliTe® compact yarns and normal ring spun doubled yarns using CTT (Constant Tension Transport) machine, a versatile test instrument to measure the yarn properties such as dynamic breaking strength, elongation, abrasion, lint, yarn faults (thick, thin places, neps), hairiness etc. EliTe® compact yarns showed higher breaking strength, more elongation, with lesser yarn faults and hairiness, less abrasiveness and less lint generating tendencies during the dynamic testing as compared to the normal ring spun doubled yarns.     

亚种间杂交水稻低结实率的生理原因分析

比较了亚种间杂交稻"W6154S×培C3111"、品种间杂交稻"W6154S×特青"和常规稻"特青"的籽粒灌浆过程中生理活性变化和结实率情况.结果表明所有供试组合(品种)的强势粒对弱势粒都具有较强的抑制作用,表现在灌浆初期弱势粒的细胞色素氧化酶活性低丽IAA氧化酶活性高,直至强势粒灌浆接近完成时,弱势粒的细胞色素氧化酶活性升高、IAA氧化酶活性降低.尤其是亚种间杂交水稻的强势粒对弱势粒的抑制作用最强,导致弱势粒灌浆不充实成为秕粒,甚至发育停止成为受精空粒.亚种间杂交稻的秕粒率、受精空粒率和未受精率分别为16.86%,15.55%和6.55%,而品种间杂交稻和常规稻上述三种比率分别为12.29%,3.03%,4.70%和6.75%,2.88%,5.09%.     

Study on the wicking property of polyester filament yarns

In this paper, the capillary rise method was applied to evaluate the wicking property of polyester filament yarns. Effects of twist, monofil cross sectional shape and texturing on the wicking height were discussed in details. The results indicated that with the increase of twist level, the wicking height ascends until reaching the maximum height, and then descends. It is also observed that under the same twist level, the wicking height of the five-leaf low-stretch yarn is the largest among all those three kinds of yarns, and then is that of the conventional low-stretch yarn. The wicking height of the parallel-drawn yarn is the smallest.     

利用谷子品种间除草剂抗性差异实现谷子免间苗技术研究

抗除草剂谷子品种与不抗除草剂谷子品种按照不同比例混合在春谷区进行生产配比试验。结果表明：按谷子播种量7．5kg／hm。标准,抗除草剂与不抗除草剂品种配比在1：1．2-1．6之间。经除草剂处理谷苗数量能够满足平地种植要求,配比在1：1．8～2．0之间能够满足坡苗数要求。     

甘蓝型双低油菜三系杂交种豫油4号的选育

豫油4号是利用细胞质雄性不育技术育成的甘蓝型双低油菜“三系”杂交种,突出表现为高产、优质、早熟、抗病等。在1993～1995年河南省油菜区试中,三年综评居第一位,平均单产2593．5kg／hm2,比同类型（双低）对照豫油2号增产26．7％,1994～1995年河南省生产试验中比秦油2号增产10．8％。抗病毒病,耐菌核病,早熟性好,全生育期231d。芥酸含量为0．241％,硫甙含量21．31μmol／g,含油量高达41．21％。     

杂交夏大豆制种必备的几个因素分析

杂交优势的利用是大幅度提高大豆产量的有效途径。杂交制种产量过低是制约杂交大豆推广的瓶颈。杂交大豆生产受种植区域、杂交亲本、气象条件和栽培措施四大因素的影响,只有同时满足各种条件,才能获得较好的制种效果。     

杂交油菜湘杂油1号的高产分析

1999至2000年对湖南省范围内湘杂油1号高产示范典型田块的油菜样量、产量结构和栽培措施进行了统计分析,结果表明,湘杂油1号产量达3000－3958．9kg/hm^2的产量结构为角果5250－6750万个／hm^2,每角20粒以上,千粒重4g以上,植株高度185－198cm,一次分枝数和二次分枝数各10个左右。     

大豆杂交种杂交豆1号选育报告

杂交豆1号是利用"三系"法生产的大豆杂交种,也是世界上第一个通过正式审定的、可商业化应用的大豆杂交种.不育系为JLCMS9A,恢复系为吉恢1号.杂交豆1号丰产性好,抗病性较强,品质优良.两年区试平均比对照品种吉林30增产21.9%,生产试验比对照增产20.8%.人工接种鉴定结果表明抗大豆花叶病毒病.籽粒脂肪含量21.09%,蛋白质含量39.19%.该品种适于吉林省中晚熟区种植.