纤维的鉴别方法

一、手感摸测法 织物的手感常能为它的纤维成份提供良好的线索。然而,经过整理、变形、不同等级的纤维常会改变手感。将织物放在拇指和食指之间摩擦,就可判定其温暖性、弹性、光滑度和干爽性。一般地说,主要的纤维比较如下: 聚丙烯腈 手感凉快、有弹性、光滑和干爽。 棉布 手感凉快、无弹性、柔软和干爽。 玻璃纤维 手感温暖、硬挺、光滑和干爽。 亚麻布 手感凉快,坚韧、硬挺和干爽。 尼纶 手感凉快、有弹性、光滑和滑溜。     

针织物手感风格的量化评价与检测实践

量化评价织物手感风格对于研究和改善织物手感有重要意义。本文采用法宝仪对不同柔软整理的针织物手感进行了量化评价,测定了样品的韧度、软度和滑度等特征值。试验表明,针织物手感的量化评价具有可行性,与主观评价结果有较好的一致性,而相对手感值更能反映样品之间的手感差异。     

湿法水刺可分散材料手感风格评价

为探究湿法成网水力缠结可分散材料的手感客观参数对其综合手感的影响,利用手感软度分析仪对湿法水刺可分散材料进行手感客观测定,根据主观评价求得的均值作为手感风格综合评价依据,利用逐步回归模型对手感客观参数进行系统筛选。结果表明:与材料手感主观评价值关系密切的客观参数为:柔软度、平滑度和硬挺度,且主观评价值与柔软度、平滑度呈负相关,与硬挺度呈正相关。同时主观评价值与柔软度、平滑度和硬挺度的偏相关系数分别为-0.970,-0.854和-0.808。可为开发高品质手感的湿法水刺可分散材料提供参考。     

织物手感值计算式

本文转载自手感计量、标准化研究委员会的“研究委员会技术报告57号”。随着标准试样标准化的进展,现在已经能够用手感值的具体数值来表达手感感觉强弱。在这个基础上能够分析手感值和力学量的关系,而且也重新研究决定了男用西服料好坏的综合手感值的计算式,有关这些已经     

涤纶织物手感风格的量化表征

为探索法宝仪在织物手感风格量化表征中的可行性,采用法宝仪测试了不同条件下涤纶织物的手感风格值,并对测试结果可靠性进行分析。选取4种不同类型的柔软剂以不同质量浓度处理涤纶织物,调湿后用于法宝仪测试,并与主观手感结果进行对比。结果表明,法宝仪可以实现柔软整理后涤纶织物手感风格的量化表征,所测手感特征值可量化展现不同种类、不同质量浓度柔软剂处理后涤纶织物的韧度、软度、滑度以及相对手感值的变化,相对手感值排序结果与主观评价结果有较好的一致性。     

制丝用水与生丝色泽手感的关系及制丝用水标准

制丝用水水质对生丝色泽、手感影响较大。故制丝用水水质不仅要注重有利于解舒和降低消耗,还应有利于生丝的色泽和手感,使所制生丝达到丝色白淡、光泽明亮、手感软滑的要求。现就水质与生丝色泽、手感的关系及制丝用水标准问题进行探讨。     

声学分析测定织物手感

与织物的视觉外观相同,织物的手感也是消费者购买纺织品的评价指标。影响织物手感的因素很多：纤维、纱线及其表面结构和后处理。测定纺织品特定手感性能的目的是用客观数值的方式表征其手感特点。介绍了一个可以定量描述织物手感特点和柔软性的测试系统,该测试系统是在声学分析的基础上进行测试的。     

织物手感评价方法的特点

简要回顾了织物手感评价的测试方法和手感信息的提取，详细分析了现有手感信息提取方法的特点和存在的缺陷，指出了织物手感今后的主要研究方向。     

根据机织物的机械性质预测织物手感

纺织工业的基本要素是纤维、纱线、织物和整理。在这些领域中的任一方面发生较重要的工艺进展时,其结果就会有新产品引入服装或家俱市场上去,首先试用的品质评定之一是织物手感。评定织物手感的一种途径是测量物理手感参数。它假设手感现象是机械性能的结果,如果选择适当的物理参数,则手感现象完全可以由织物的机械性质来表示。这种概念具有一定的优点,它用组成的力学参数表示织物手感,因而避免了在纯粹主观评定中     

织物柔软度和手感的检测与改善

<正>1面料的手感对服装来说,面料的手感是非常重要的性能。对消费者来说,购买服装的考量因素,除了尺寸、款式、设计和颜色之外,服装的手感也是一个决定性因素,因为它决定了服装的穿着舒适度。在过去的100多年中,人们对面料手感的定义进行了很多的研究,其中最主要的是Howorth和Oliver的研究,他们评价了精纺羊毛织物的手感。采用多因素分析法,他们发现面料的手感主要取决于以下几个方面:     

Photocatalytic oxidation of gaseous 2-chloroethyl ethyl sulfide over TiO2

Photocatalytic oxidation of gaseous 2-chloroethyl ethyl sulfide (2-CEES, ClCH2CH2SCH2CH3) over TiO2 illuminated with UV light and maintained at 25 or 80 degrees C in air has been investigated. 2-CEES was found to suffer progressive oxidation to yield ethylene (CH2CH2), chloroethylene (ClCHCH2), ethanol (CH3CH2OH), acetaldehyde (CH3C(O)H), chloroacetaldehyde (ClCH2C(O)H), diethyl disulfide (CH3CH2S2CH2CH3), 2-chloroethyl ethyl disulfide (ClCH2CH2S2CH2CH3), and bis(2-chloroethyl) disulfide (ClCH2CH2S2CH2CH2Cl) as the main primary intermediates, and water (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), surface sulfate ions (SO4(2-)), and hydrogen chloride (HCl) as the final products. Trace concentrations of gaseous 2-chloroethanol (ClCH2CH2OH), ethanesulfonyl chloride (CH3CH2SO2Cl), ethyl thioacetate (CH3CH2SC(O)CH3), and considerable amounts of acetic acid (CH3C(O)OH), crotonaldehyde (CH3CHCHC(O)H), methyl acetate (CH3C(O)OCH3), and methyl formate (CH3OC(O)H) were also detected in the gas phase during the photooxidation conducted at 80 degrees C. Increase in temperature from 25 to 80 degrees C accelerates formation of gaseous ethanol, acetaldehyde, chloroacetaldehyde, diethyl disulfide, 2-chloroethyl ethyl disulfide, and bis(2-chloroethyl) disulfide but suppresses ethylene and chloroethylene production at initial stages of the process. Some aspects of the possible reaction mechanism leading to this wide array of intermediates and final products are discussed.     

Solar photolysis of CH2I2, CH2ICl, and CH2IBr in water, saltwater, and seawater

Ultraviolet-visible absorption spectroscopy and purge-and-trap GC-MS were used to determine the rates and products of the photodissociation of low concentrations of CH2I2, CH2IBr, and CH2ICl in water, saltwater (0.5 M NaCl), and seawater in natural sunlight. Photoproducts of these reactions include iodide (I-) and, in salt- and seawater environments, CH2XCl (where X = Cl, Br, or I). Thus, CH2ICl was produced during CH2I2 photolysis (with a molar yield of 35 +/- 20%), CH2BrCl from CH2IBr photolysis, and CH2Cl2 from CH2ICl photolysis (in lower yields of 6-10%). Formation of these chlorine-atom-substituted products may be via direct reaction of Cl- with either (A) the isopolyhalomethane photoisomer or associated ion pair (e.g., CH2I+-I-) or (B) the initially produced CH2I. photofragment. Estimated quantum yields for photodissociation were 0.62 +/- 0.09, 0.17 +/- 0.03, and 0.26 +/- 0.06 for CH2I2, CH2IBr, and CH2ICl, respectively, in 0.5 M NaCl, with only small differences from these values in water and seawater. The much higher quantum yield of CH2I2 photolysis compared to CH2IBr and CH2ICl photolysis may be explained by the higher yield of the isodiiodomethane photoisomer of CH2I2, resulting in reduced geminate recombination of the initially produced radical photofragments back to the parent molecule. We use a radiative transfer model with measured absorption cross-sections in saltwater to calculate seasonal values of CH2I2, CH2IBr, and CH2ICl photodissociation in surface seawater at midlatitudes (50 degrees N) and show that a significant proportion of CH2ICl in surface seawater may arise from CH2I2 photodecomposition. We also suggest that surface seawater photolysis of CH2I2 over an 8 h period may contribute up to approximately 10% of the surface seawater I- levels, with implications for the increased deposition of O3 to the surface ocean.     

Formation of methyl nitrite and methyl nitrate during plasma treatment of diesel exhaust

FTIR spectroscopy was used to identify CH3ONO and CH3ONO2 as products of the nonthermal plasma treatment of simulated diesel exhaust. This is the first observation of CH3ONO formation in such systems. The yield of CH3ONO relativeto CH3ONO2 scaled linearly with the average [NO]/ [NO2] ratio in the system. A plot of [CH3ONO]/[CH3ONO2] versus [NO]/[NO2] gives a slope of 1.81 +/- 0.30. This result is indistinguishable from the literature value of the rate constant ratio k(CH3O + NO)/k(CH3O + NO2) = (2.6 x 10(-11))/ (1.5 x 10(-11)) = 1.73 +/- 0.37. The experimental observations suggest that reactions of CH3O radicals with NO and NO2 are the sources of CH3ONO and CH3ONO2 in such systems. The linear relationship between the yields of CH3ONO and CH3ONO2 provides a means of estimating the yield of these compounds during nonthermal plasma treatment of diesel exhaust.     

OH radical-initiated reaction of 3-hexene-2,5-dione: formation of methylglyoxal

3-Hexene-2,5-dione [CH3C(O)CH=CHC(O)CH3] and other unsaturated 1,4-dicarbonyls are formed from the atmospheric photooxidations of aromatic hydrocarbons. We have reinvestigated the formation of methylglyoxal from the gas-phase reaction of OH radicals with 3-hexene-2,5-dione in the presence of NO at room temperature and atmospheric pressure of air using in situ Fourier transform infrared spectroscopy. No evidence for the formation of methylglyoxal was obtained, with the IR spectra showing that methylglyoxal is, at most, a minor reaction product with a molar formation yield of <10% (and more likely <1%). This confirms our earlier study (Tuazon et al. Environ. Sci. Technol. 1985, 19, 265) and suggests that the CH3C(O)CH(OH)CHO and CH3C(O)CH(OH)CH(ONO2)C(O)CH3 observed by Bethel et al. (Environ. Sci. Technol. 2001, 35, 4477) are the major first-generation reaction products.     

The photolysis of dihalomethanes in surface seawater

Laboratory experiments were carried out with different types of natural and artificial seawaterto study the aqueous degradation kinetics of the photolabile compounds CH2I2, CH2Brl, and CH2ClI. Irradiation studies were carried out with a 1-kW Xe lamp, optically filtered to simulate the solar spectrum at the earth's surface. Halocarbon concentrations in the samples were analyzed by purge-and-trap gas chromatography/mass spectrometry. Generally, the compounds studied were found to follow first-order removal kinetics on irradiation. However, in the case of CH2I2, deviations from first-order removal occurred after a few minutes of irradiation, probably indicating radical recombination. Photolytic lifetimes varied from 12 min for CH2I2 to 13 h for CH2ClI in natural surface seawater at 15 degrees C and an irradiation intensity corresponding to overhead sun (solar zenith angle = 0 degrees). Photolysis of CH212 in artificial and natural seawater generated CH2CII with a yield of 25-30%, suggesting that this reaction is an important source of marine CH2ClI. Dark-incubations of CH2I2 for up to one week showed that this compound does not undergo nucleophilic attack by chloride, indicating that photolysis is the main abiotic degradation mechanism of CH2I2 in seawater.     

Production and reproduction of Fleckvieh,Brown Swiss,and 2 strains of Holstein-Friesian cows in a pasture-based,seasonal-calving dairy system

The first objective of this study was to compare the productive and reproductive performance of Holstein-Friesian (CH HF), Fleckvieh (CH FV), and Brown Swiss (CH BS) cows of Swiss origin with New Zealand Holstein-Friesian (NZ HF) cows in pasture-based compact-calving systems; NZ HF cows were chosen as the reference population for such grazing systems. The second objective was to analyze the relationships within and between breeds regarding reproductive performance, milk yield, and body condition score (BCS) dynamics. On 15 commercial Swiss farms, NZ HF cows were paired with Swiss cows over 3 yr. Overall, the study involved 259 complete lactations from 134 cows: 131 from 58 NZ HF, 40 from 24 CH HF, 43 from 27 CH FV, and 45 from 25 CH BS cows. All production parameters were affected by cow breed. Milk and energy-corrected milk yield over 270 d of lactation differed by 1,000 kg between the 2 extreme groups; CH HF having the highest yield and CH BS the lowest. The NZ HF cows had the greatest milk fat and protein concentrations over the lactation and exhibited the highest lactation persistency. Body weight differed by 90 kg between extreme groups; NZ HF and CH BS being the lightest and CH HF and CH FV the heaviest. As a result, the 2 HF strains achieved the highest milk production efficiency (270-d energy-corrected milk/body weight^0.75). Although less efficient at milk production, CH FV had a high 21-d submission rate (86%) and a high conception rate within 2 inseminations (89%), achieving high pregnancy rates within the first 3 and 6 wk of the breeding period (65 and 81%, respectively). Conversely, poorer reproductive performance was recorded for CH HF cows, with NZ HF and CH BS being intermediate. Both BCS at nadir and at 100 d postpartum had a positive effect on the 6-wk pregnancy rate, even when breed was included in the model. The BCS at 100 d of lactation also positively affected first service conception rate. In conclusion, despite their high milk production efficiency, even in low-input systems, CH HF were not suited to pasture-based seasonal-calving production systems due to poor reproductive performance. On the contrary, CH FV fulfilled the compact-calving reproduction objectives and deserve further consideration in seasonal calving systems, despite their lower milk production potential.     

Temperature effects on the removal of potential HFC replacements, CF3CH2CH2OH and CF3(CH2)2CH2OH, initiated by OH radicals

The gas-phase kinetic coefficients of OH radicals with two primary fluorinated alcohols, CF(3)CH(2)CH(2)OH (k(1)) and CF(3)(CH(2))(2)CH(2)OH (k(2)), potential replacements of hydrofluorocarbons (HFCs), are reported here as a function of temperature (T = 263-358 K) for the first time. k(1) and k(2) (together referred as k(i)) were measured under pseudo-first-order conditions with respect to the initial OH concentration using the pulsed laser photolysis/laser induced fluorescence technique. The observed temperature dependence of k(i) (in cm(3) molecule(-1) s(-1)) is described by the following Arrhenius expressions: k(1)(T) = (2.82 ± 1.28) × 10(-12) exp{-(302 ± 139)/T} cm(3) molecule(-1) s(-1) and k(2)(T) = (1.20 ± 0.73) × 10(-11) exp{-(425 ± 188)/T} cm(3) molecule(-1) s(-1).The uncertainties in the Arrhenius parameters are at a 95% confidence level (± 2σ). Uncertainties in k(i)(T) include both statistical and systematic errors. Activation energies were (2.5 ± 1.2) kJ/mol and (3.6 ± 1.6) kJ/mol for the OH-reaction with CF(3)CH(2)CH(2)OH and CF(3)(CH(2))(2)CH(2)OH, respectively. The global lifetime (τ) at 275 K for CF(3)CH(2)CH(2)OH and CF(3)(CH(2))(2)CH(2)OH due to the OH-reaction was estimated to be ca. 2 weeks and 5 days, respectively. The reported Arrhenius parameters can be used in 3D models that take into account the geographical region and season of emissions for estimating a matrix of instantaneous lifetimes. As a consequence of the substitution of the -CH(3) group by a -CH(2)OH group in HFCs, such as CF(3)CH(2)CH(3) and CF(3)(CH(2))(2)CH(3), the tropospheric lifetime with respect to the OH reaction is significantly shorter and, since their radiative forcing is similar, global warming potentials of CF(3)CH(2)CH(2)OH and CF(3)(CH(2))(2)CH(2)OH are negligible. Therefore, CF(3)CH(2)CH(2)OH and CF(3)(CH(2))(2)CH(2)OH seem to be suitable alternatives to HFCs.     

Characterization of quinoa protein–chitosan blend edible films

Quinoa protein/chitosan films were obtained by solution casting of blends of quinoa protein extract (PE) and chitosan (CH). Films from a PE/CH blend were characterized by FTIR, X-ray diffraction, thermal analysis, and SEM. The tensile mechanical, barrier, and sorption properties of the films were also evaluated. The blend of PE with CH yielded mechanically resistant films without the use of a plasticizer. The film had large elongation at break, and its water barrier properties showed that they were more hydrophilic than CH film. The thickness and water-vapor permeability of PE/CH (v/v) 1/1 blend film increased significantly compared to pure CH films. CH films are translucent in appearance and yellowish in blend with PE. By blending anionic PE with cationic CH an interaction between biopolymers was established with different physicochemical properties from those of pure CH. Drying and sorption properties show significant differences between PE/CH blend film and CH film. The structural properties determined by XRD, FTIR and TGA showed a clear interaction between quinoa proteins and CH, forming a new material with enhanced mechanical properties.     

Comparing effects of α‐ vs. β‐chitosan coating and emulsion coatings on egg quality during room temperature storage

Effects of α‐ and β‐chitosan (CH), soybean oil (SO) and their emulsions (CH:SO = 2:3) as coating materials on selected internal quality and sensory properties of eggs were evaluated during 5 weeks storage at 25 °C. After 3 weeks of storage, α‐ and β‐CH‐coated eggs changed to B grade, while SO‐ and emulsion‐coated eggs preserved grade A quality. Weight loss of eggs coated with SO and CH:SO emulsions was <2.0% vs. 5.3–5.8% for noncoated and CH‐coated eggs after 5 weeks of storage. β‐CH (0.9%) maintained lower weight loss of eggs than α‐CH (1.2%) only at 1‐week storage. Albumen pH of eggs coated with SO and CH:SO emulsions decreased progressively throughout storage. Eggs coated with β‐CH:SO emulsion and SO were significantly glossier than noncoated eggs. Consumers indicated positive purchase intent (69.17–76.67%) for all coated eggs. Overall, α‐CH:SO and β‐CH:SO emulsions extended egg shelf life by at least 3 weeks during room temperature storage.     

Chitosan and Protein Coatings Affect Yield, Moisture Loss, and Lipid Oxidation of Pink Salmon (Oncorhynchus gorbuscha) Fillets During Frozen Storage

The effects of chitosan (CH1 = 1% and CH2 = 2% solution), egg albumin (EA), soy protein concentrate (SPC), pink salmon protein powder (PSP), and arrowtooth flounder protein powder (AFP) as edible coatings on quality of skinless pink salmon fillets were evaluated during 3 mo frozen storage. Coating with 2% chitosan (CH2) resulted in significantly higher yield than coating with PSP and AFP. The thaw yield of salmon fillets coated with CH2 was higher than those of the control and fillets coated with AFP. The noncoated, CH1‐, and CH2‐coated fillets had similar drip loss (0.4% to 1.2%), which was lower than those observed for PSP‐ and AFP‐coated fillets. All fillet samples had similar cook yield (84.2% to 88.8%). The fillet coated with CH1, CH2, SPC, and EA had significantly higher (P < 0.05) moisture content after thawing than the control noncoated fillets. Coating with CH1 and CH2 was effective in reducing about 50% relative moisture loss compared with the control noncoated fillets. Chitosan (CH1 and CH2) and SPC delayed lipid oxidation. There were no significant (P > 0.05) effects of coating on a*, b*, and whiteness values for cooked fillets after 3 mo frozen storage.