Analysis of some comfort and structural properties of cotton/spandex plain and 1×1 rib knitted fabrics

Spandex is increasingly used in either every course or alternating courses of knitted fabrics to impart a greater level of stretch and form stability than that can be achieved with cotton alone. The incorporation of spandex to the fabric structure effects many of the fabric properties. In this study, 100% cotton, half-plated and full-plated, plain and rib fabrics which are very commonly used in underwear and outerwear clothing are investigated for physical, dimensional, geometrical, and some comfort properties and compared to each other. Several conclusions could be obtained such as the wicking heights of the plain fabrics were higher than those of the 1×1 rib fabrics. Transfer wicking ratios of the half-plated fabrics were the highest, whereas the transfer wicking ratios of the full-plated fabrics were the lowest. Extension under constant load and residual deformation ratios decreased with the addition of spandex and the increase in spandex content. Plain fabrics generally performed better than 1×1 rib fabrics in terms of residual deformation ratios.     

Investigation of the fastness properties and color values of cotton fabrics knitted from ring spun and Sirospun® yarns

Sirospun yarn production is a new approach to produce two‐folded and twisted yarns. This method integrates the spinning and folding action in a single step. Therefore, it may have some important advantages such as simplicity of the process, lower production costs, lower investment, space saving, etc. The purpose of the study is to compare the color fastness and colorimetric properties of sirospun yarn, single and two‐folded ring spun yarns produced by same cotton fiber blend. Therefore, three reactive dyes were applied at 1% omf (on mass of fabric) depth of shade to the single jersey fabrics which are produced by sirospun yarn, single and two‐folded ring spun yarns at three different counts. The examination of color coordinates of undyed and dyed samples on CIELAB color space shows that undyed sirospun fabrics show slightly higher whiteness than both undyed single and two‐folded ring fabrics for all three yarn counts. Also, the color strength values of the samples are determined as slightly different for all three dyes. The experimental studies show that sirospun yarns have no disadvantages with respect to conventional folded and twisted yarns when their fastness properties were compared.     

Influence and comparison of emerging techniques of yarn manufacturing on physical–mechanical properties of polyester-/cotton-blended yarns and their woven fabrics

Abstract

In this study, the physical–mechanical properties of ring spun, ring compact, rotor and air-vortex yarns were investigated. The study was carried with yarn having linear densities of 24.4 tex and 36.7 tex, which were then converted to woven fabrics. The ring spun yarns have higher values of strength but also with higher strength irregularities. Extra-ordinarily low hairiness was observed in air-vortex yarns due to its unique yarn formation technique. The deviation rate (DR) of yarns have correlation with the mass spectrogram of respective yarns obtained from USTER Tester 5. Rotor and air-vortex yarns exhibited higher coefficient of friction. The woven fabrics made from ring spun yarns exhibited higher tensile and tear strength with higher elongation at break. The fabrics made from air-vortex yarns have very good pilling grade due to less protruding fibres on their surface and good structural integrity.     

Ring frame process parameters and fabric comfort. Part I – low-stress mechanical properties of fabrics

Influence of ring frame process parameters, namely twist multiplier of yarn, spindle speed and ring frame draft, on some of the yarn characteristics has been studied. The low-stress mechanical characteristics of woven and knitted fabrics made out of these yarns have also been reported in the present paper. Yarn packing factor, which is directly related with the yarn diameter, has direct impact on fabric comfort related characteristics. All the studied ring frame process parameters, i.e. yarn twist, ring frame draft and spindle speed, have inverse effect on the yarn diameter, which means the yarn diameter reduces with the increase in one of the process parameters by keeping the other two parameters constant. The impact of draft on reduction in yarn diameter is found to be higher as compare to other two parameters. All these ring frame process parameters have significant impact on other yarn parameters also. The increase in yarn twist, spindle speed and draft result in increase in flexural rigidity, unevenness and imperfections of yarn and decrease in yarn hairiness. All the low-stress mechanical properties, i.e. tensile, shear, bending, compression and surface, of both woven and knitted are affected by the above ring frame parameters. The thickness of fabrics changes with the yarn compactness, i.e. with the reduction in yarn diameter. The study revealed that by changing the above ring frame process parameters, it is possible to manipulate the fabric handle characteristics without changing the fabric constructional parameters.     

Study on dyeing and fastness properties of wool–polyester blend fabrics using novel mono azo-naphthalimide dyes

The objective of the research reported in this paper was to investigate the determinants of textile-export performance by using data for major textile-exporting countries. Gross exports and net exports were the two measures of export performance. Multiple-regression analysis was used to investigate the relationship between export performance and a country's resource endowments (physical capital, technological capital, human capital) and industry characteristics (unit labor costs, domestic-apparel production). Cross-section data for 1970, 1975, 1980, and 1985 were used in the analysis. Major findings indicated that countries with more physical capital were more likely to be gross or net textile exporters, whereas countries with higher levels of human capital and more domestic-apparel production were less likely to be gross or net textile exporters. The impact of technological capital varied according to whether a country was a gross or net textile exporter.     

Comparison of the properties of Ring,Solo, and Siro core‐spun yarns

In this research, core‐spun yarns with an acrylic sheath fiber and a nylon flat core have been produced on the Ring, SIRO, and Solo spinning systems and the effects of some factors were investigated. The studied factors consist of filament pre‐tension (i.e. 1, 7/5, 10, 15, 50, and 100 g), spinning system (Ring, SIRO, and Solo), and feed position of the core filament in the strands of sheath fibers (six types of feed positions). Also, their physical and mechanical properties, including strength, elongation percentage, abrasion resistance, percentage of coefficient of variation (CV%), and hairiness, were all investigated. Finally, in each stage, the best case was determined. The results show that the quality of the core‐spun yarns produced by the SIRO spinning system is better than that of the Ring and Solo core‐spun yarns.     

Effect of the particle size of fluorocarbon‐based finishing agents on fastness and color properties of 100% cotton knitted fabrics

This study examines the effect of the particle size of fluorocarbon‐based water‐oil‐soil‐repellent finishing agents on color fastness and colorimetric properties by experimental analyses. Therefore, two finishing agents with different particle sizes were applied to red‐dyed and blue‐dyed knitted fabric samples of single jersey and rib‐structured knits, produced from 100% cotton yarns. The results show that smaller particle size causes less color change for all washings (0, 1 and 5), both of the dyes and the fabric structures (single jersey and rib). Also, it is observed that smaller particle size positively affects the rub fastness results.     

Preparation of microencapsulated carbon microspheres coated by magnesium hydroxide/polyethylene terephthalate flame–retardant functional fibers and its flame retardant properties

In order to improve the compatibility between the flame retardants of carbon microspheres coated by magnesium hydroxide (MH@CMSs) and the PET matrix and improve the spinnability of the masterbatch, MH@CMSs have been microencapsulated by PET to obtain microencapsulated carbon microspheres coated by magnesium hydroxide flame retardants – MMH@CMSs.Morphologies and structures of MMH@CMSs have been studied by scanning electron microscope (SEM), transmission electron microscopy (TEM), and FTIR, which showed that an organic shell layer of PET as capsule wall was coated on the surface of MH@CMSs. A series of MMH@CMSs/PET fibers with different MMH@CMSs contents were successfully prepared through the melt-spinning method. The morphology and structure of MMH@CMSs/PET fibers were characterized by SEM and FTIR. The flame retardancy of MMH@CMSs/PET fibers was determined via limiting oxygen index (LOI) test and cone calorimeter. Results showed that the MMH@CMSs/PET fibers possessed optimum flame retardancy when the MMH@CMSs content is 0.6 wt.%, at which the LOI reached a maximum of 25.8, and the pk-HRR, total heat release, and total smoke release were reduced by 27.4, 20, and 13.6%, compared with pure PET fibers, respectively. Moreover, the flame-retardant mechanism was studied by thermogravimetric analysis, thermogravimetric analysis-infrared spectrometry, and the SEM of the residue char, which disclosed that MMH@CMSs enhanced the thermal stability of PET fibers, and promoted PET fibers to form a dense and continuous protective char layer that effectively blocked heat transfer and combustible gas release.     

Thermal,mechanical and water adsorption properties of corn starch–carboxymethylcellulose/methylcellulose biodegradable films

The objective of this study was to investigate the effect of the addition of methylcellulose and carboxymethylcellulose on the thermal, mechanical and water adsorption properties of starch-based films plasticized with glycerol or polyethylene glycol (PEG). Mechanical tests showed that as the methylcellulose and carboxymethylcellulose proportion increased, starch films became more resistant to break, resulting in higher TS values. Besides there has been a positive effect on the elasticity of starch films realized by a considerable increase in E% values. Depending on the plasticizer type, either single or dual glass transitions were seen in DSC thermograms. One glass transition temperature was observed for films plasticized with glycerol, on the contrary, dual glass transitions were detected for PEG plasticized films. This behavior was attributed to the phase separation of the PEG. In addition, the presence of an endothermic peak in the thermograms of PEG plasticized films was taken as another indicator of the phase separation. As a result, it was suggested that PEG was not as compatible as glycerol with the composite polysaccharide matrix and plasticizer type was the main factor that shaped the thermal profiles of the film samples. Water adsorption isotherm data showed that samples displayed nonlinear sorption profile which is typical for hydrophilic films. In all films tested, equilibrium moisture contents, increased almost linearly up to a a_w of 0.65–0.85, beyond where a sharp increase was noted. Adsorption data was adequately fitted by BET and GAB models. Eventually, it can be concluded that film forming properties of starch can be improved by incorporation of methylcellulose and carboxymethylcellulose to the polymer matrix.     

Properties of an αs-casein-rich casein fraction: Influence of dialysis on surface properties,miscibility, and micelle formation

In this study, the surface tension, miscibility, and particle size distribution of a solution containing an α_s-casein (CN)-rich CN fraction (54 wt % α_s-CN, 32 wt % β-CN, and 15 wt % κ-CN) were determined at pH 6.6. The nondialyzed CN fraction was compared with a dialyzed one. In the nondialyzed sample, every charge on the protein was compensated by 0.3 charges coming from counterions, whereas in the dialyzed sample, only 0.2 charges could be assigned to each charge on the protein. This relation was determined by calculating the charges at the proteins, taking the measured mineral content into account. The surface tension was measured as a function of the protein concentration by the du Noüy ring method at room temperature. Results indicated alterations in the surface properties after reduction of counterions. The equilibrium surface tension above the critical micelle concentration increased from 40.1 × 10⁻³ to 45 × 10⁻³ N/m, the critical micelle concentration increased from 0.9 × 10⁻⁴ to 2 × 10⁻³ mol/L, and the minimal area occupied per molecule at the surface increased from 2.4 × 10⁻¹⁸ to 4.6 × 10⁻¹⁸ m². Cloud points were determined by measuring the absorbance of CN solutions as a function of the temperature. The cloud points were found to be concentration dependent and had a minimum at 0.2 wt % at 34°C for nondialyzed CN and at 0.25 wt % at 28°C for dialyzed CN, again demonstrating the influence of counterion reduction. Below the cloud point, a micellar phase was found to exist. The hydrodynamic diameter of the micelles were characterized by dynamic light scattering in both auto- and cross-correlation mode. However, no influence of reduction in counterions could be observed, possibly due to the fact that dynamic light scattering is not a suitable method for this type of system. The presence of self-assembled structures was verified by freeze-fracture electron microscopy. The observed differences between dialyzed and nondialyzed samples were explained by changes in the counterion cloud surrounding the proteins. Consequently, the electrostatic interactions between as well as within the CN are altered by dialysis, which, in turn, affects the behavior at the surface as well as the properties in the solution.     

Effects of γ-irradiation on Listeria monocytogenes population,colour, texture and sensory properties of Feta cheese during cold storage

Feta, a white brine cheese, was produced and contaminated with Listeria monocytogenes. Contamination occurred either at the beginning (pre-process contamination) or at the end of Feta manufacturing (post-process contamination). In the first case the milk was contaminated with 10³ cfu/ml, and 2 months later, in the final product, the L. monocytogenes population was approximately 10⁵ cfu/g. In the second case, the brine (NaCl, 7% w/v), in which the Feta was packaged, was contaminated with 10³ cfu/ml. Contaminated Feta samples were vacuum-packaged and exposed to irradiation doses of 1.0, 2.5 and 4.7 kGy and stored at 4 °C for a month. In the pre-process contaminated samples none of the irradiation doses eliminated L. monocytogenes; however the highest dose reduced the viable population to a level which is in compliance with EC regulations. In the post-process contamination, the 2.5 kGy and 4.7 kGy doses reduced L. monocytogenes counts below the detection limit. Irradiation had no effect on the texture of Feta. Irradiation at 4.7 kGy increased Feta's redness and decreased its yellowness and lightness. Sensorial analyses showed that at the 4.7 kGy dose, the aroma profile of Feta was temporarily affected, since it was restored after 30 days of cold storage.     

Effects of high hydrostatic pressure on microstructure,physicochemical properties and in vitro digestibility of oat starch/β-glucan mixtures

Oats do not contain gluten protein, and oat dough structure is formed mainly through the hydrogen bonding of starch and β-glucan. As a non-thermal processing technology, high hydrostatic pressure (HHP) is mainly used to modify starch and protein in food processing. This study investigated the effects of HHP treatment on the morphological, structural, thermal, pasting and in vitro digestion properties of oat starch/β-glucan mixtures. Results showed that β-glucan interconnects with amylose through hydrogen bonding and has a protective effect on the crystalline region of oat starch. Effect of HHP treatment on the crystal structure of mixture system goes through crystal structure perfection stage, crystallisation disintegration and gelatinisation stage. After 300–400 MPa treatment, the changes in particle surface were not obvious, the phase transition temperature, the ΔH_gel and the PT of mixtures increased, while the particle size, viscosity and BD values decreased. After 500–600 MPa treatment, mixtures were completely gelatinised, most of the particles swelled and deformed, the particle size increased significantly. The principal component analysis results show that the complexes were distributed in the same region with similar properties after the 300–400 MPa and 500–600 MPa treatments, respectively.     

Optimization of hydroxypropylmethylcellulose,yeast β-glucan,and whey protein levels based on physical properties of gluten-free rice bread using response surface methodology

Response surface methodology (RSM) was used to analyze effects of hydroxypropylmethylcellulose (HPMC), yeast β-glucan, and whey protein isolate (WPI) on physical properties of gluten-free bread baked from formulas based on rice starch. A Box–Behnken design with three independent variables (HPMC, yeast β-glucan, and WPI) and three levels was used to develop models for the different responses (physical properties). Individual contour plots of the different responses produced from the models were compared to the corresponding reference wheat bread data and were superimposed to locate gluten-free bread formulations that met the wheat bread standards for spread ratio, specific volume, hardness, cohesiveness, chewiness, and crumb color L∗ value. The optimal formulation, determined from the data, contained 4.35 g/100 g HPMC, 1 g/100 g β-glucan, and 0.37 g/100 g WPI, rice starch basis. Predicted values of the optimized bread were experimentally tested and compared with the experimental wheat bread data. A good agreement among these data was observed. Moreover, the optimized rice starch bread was found to be acceptable according to the results of sensory analysis.     

Two flavanone compounds from litchi (Litchi chinensis Sonn.) seeds,one previously unreported,and appraisal of their α-glucosidase inhibitory activities

Using a bioactivity-guided method, a new and a previously reported flavanone glycoside were isolated from 50% ethanol extract of litchi (Litchi chinensis Sonn.) seeds. Column chromatography using macroporous resin, silica gel and Sephadex LH-20 was applied during the isolation, and the method of PMP derivatisation was performed to investigate the component sugar of the compounds. The structures of the compounds were elucidated by ¹H, ¹³C, and 2D NMR (HMQC, HMBC) spectroscopy and HR-ESIMS. Compound 1 was identified as (2R)-naringenin-7-O-(3-O-α-l-rhamnopyranosyl-β-d-glucopyranoside), a new, natural product that had been synthesised previously. Compound 2 was (2S)-pinocembrin-7-O-(6-O-α-l-rhamnopyranosyl-β-d-glucopyranoside). The two isolated compounds showed activity in the α-glucosidase inhibition assay.     

The effects of MgSO4, d-glucono-δ-lactone (GDL), sucrose,and urea on gelation properties of pectic polysaccharide from soy hull

The monosaccharide composition of pectic polysaccharide extracted from soy hull under assistance of microwave was firstly analyzed. Soy hull pectic polysaccharide (SHPP) mainly contains galactose, xylose, galacturonic acid, arabinose, glucose and rhamnose with a molar ratio of 4.7:2.5:1.5:3.8:3.2:3.0. The gelation properties of SHPP as a function of Mg²⁺, GDL, sucrose, and urea concentration were then systematically studied. Mg²⁺ can induce the gelation of SHPP but low concentration Mg²⁺ require more time to cross-linking SHPP molecular chains. GDL can strengthen the elasticity of SHPP/Mg²⁺ gel, while sucrose can also strengthen the network through hydrophobic interaction, however 30 wt% sucrose can weaken the SHPP/Mg²⁺ gel network. 2 mol/L urea can collapse the gel network formed by 3 wt% GDL with 0.1 mol/L Mg²⁺, which suggests that the junction zone of SHPP/GDL/Mg²⁺ system is formed through hydrogen bonding.     

Effects of β-κ-casein (CSN2-CSN3) haplotypes, β-lactoglobulin (BLG) genotypes, and detailed protein composition on coagulation properties of individual milk of Simmental cows

The aim of this study was to investigate the effects of CSN2-CSN3 (β-κ-casein) haplotypes, BLG (β-lactoglobulin) genotypes, content of milk protein fractions, and protein composition on coagulation properties of milk (MCP). Rennet coagulation time (RCT) and curd firmness (a₃₀) were measured using a computerized renneting meter, and the contents of major milk protein fractions were quantified by reversed-phase HPLC in individual milk samples of 2,167 Simmental cows. Cow genotypes at CSN2, CSN3, and BLG were ascertained by reversed-phase HPLC, and CSN2-CSN3 haplotype probabilities were estimated for each cow. Phenotypes for MCP were regressed on CSN2-CSN3 haplotype probabilities using linear models that also included the effects of herd-test-day, parity, days in milk, pH, somatic cell score, renneting meter sensor, sire of the cow, BLG genotype, and content of major protein fractions or, alternatively, protein composition. When the statistical model did not account for protein fraction contents or protein composition, haplotypes carrying CSN3 B were associated with shorter RCT and greater a₃₀ compared with those carrying CSN3 A. Haplotypes carrying CSN2 B had the effect of decreasing RCT and increasing a₃₀ relative to haplotype A²A. When effects of protein fractions content or protein composition were added to the model, no difference across haplotypes due to CSN3 and CSN2 alleles was observed for MCP, with the exception of the effect of CSN2 B on RCT, which remained markedly favorable. Hence, the effect of CSN3 B on MCP is related to a variation in protein composition caused by the allele-specific expression of κ-casein, rather than to a direct role of the protein variant on the coagulation process. In addition, the favorable effect exerted by CSN2 B on a₃₀ was caused by the increased β-casein content in milk. Conversely, CSN2 B is likely to exert a direct genetic effect on RCT, which does not depend upon variation of β-casein content associated with CSN2 B. Increased RCT was observed for milk yielded by BLG BB cows, even when models accounted for protein composition. Rennet clotting time was favorably affected by κ-casein content and percentage of κ-casein to total casein, whereas a₃₀ increased when contents and percentages of β-CN and κ-CN increased. Changes of milk protein composition and allele frequency at casein and whey protein genes affect variation of MCP.     

Comparative study on the physicochemical properties of κ-carrageenan extracted from Kappaphycus alvarezii (doty) doty ex Silva in Tawau,Sabah, Malaysia and commercial κ-carrageenans

κ-Carrageenan is a linear, sulphated polysaccharide that is widely used in the food industry as a gelling agent due to its lack of toxicity and biocompatibility. In this study, the physicochemical properties of κ-carrageenan (TA150) derived from Kappaphycus alvarezii (formerly Eucheuma cottonii) in Tawau, Sabah were investigated and compared to commercial κ-carrageenan (SeaKem CM611, Gelcarin GP812, Gelcarin GP911 NF, and Grindsted^® carrageenan CL220). TA150 exhibited the lowest lightness but highest yellowness, with L^∗ and b^∗ values reported as 82.69 and 17.16, respectively. The rupture strength of κ-carrageenan increased significantly with increasing concentration (p < 0.05). The water losses from κ-carrageenan gel increased with increasing storage times. TA150 lost the most water within 10 days of storage time. The water-holding capacity (WHC) of κ-carrageenan gel was reported to be excellent (>90%) under all storage temperatures (25 °C, 4 °C and −18 °C). The moisture content, ash, acid-insoluble matter, and sulphate levels of κ-carrageenan samples were reported as 3.65–11.41%, 17.75–33.18%, 0.22–3.74%, and 12.00–19.71%, respectively. These samples were low in fat, protein, and crude fibre contents. The potassium content in κ-carrageenan was highest in Gelcarin GP812 (100.42 g/kg), followed by Grindsted^® carrageenan CL220 (61.92 g/kg), TA150 (54.60 g/kg), Gelcarin GP911 NF (40.90 g/kg) and SeaKem CM611 (15.76 g/kg). No heavy metals were detected in TA150 and the other commercial κ-carrageenan samples except for lead. However, the concentration of lead detected in the κ-carrageenan samples fell within the acceptable ranges (<5 mg/kg) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).