A study on coarse Hanji yarn manufacturing and properties of the Hanji fabric

Hanji (Korean traditional paper) yarn displays excellent humidity control, air permeability, and absorbency as well as pleasantness to the touch due to its structural characteristics, and thus, it has been developed as a new eco-friendly fibrous materials. In this study, Hanji, having a basis weight of 8 and 10 g/m², was prepared using mulberry fibers. The prepared Hanji was cut into Hanji tape of 5–10 mm in width using a rotary slitter and then the tape was twisted to manufacture Hanji yarn. To ensure a uniform twist of Hanji yarn and a smooth twisting process, a water supply system was designed to provide water directly at the twisting zone. At a fixed spindle speed, the feeding speed of the delivery roller was varied to provide different twist numbers for the Hanji yarn. The Hanji yarn manufactured with water treatment has higher tensile properties and a softer touch than the Hanji yarn prepared without water treatment. The Hanji yarns have count numbers of 7–11 Ne and tensile strengths of 1.0–1.2 gf/d. Moreover, the fabric from Hanji yarn shows an excellent color fastness of 4.0 grade, staining of 4–5 to washing, and 4–5 grade to dry cleaning.     

Evaluation of bamboo charcoal/stainless steel/TPU composite woven fabrics

Composite woven fabric satisfies what people require. Bamboo charcoal (BC) has been identified as a multifunctional material that has far-infrared ray, anions, deodorization and etc. BC fibers and yarns were made of bamboo charcoal powders and have further become a pervasive materials used in textile industry. In this study, cotton yarns, stainless steel/cotton (SS/C) complex yarn, bamboo charcoal/cotton (BC/C) complex yarns were woven into the plain, twill and Dobby composite woven fabrics. The warp yarn was composed of cotton yarns, and the weft yarn was made up of BC/C and SS/C complex yarns with a picking ratio of 1:1 and 3:1. Thermoplastic polyurethanes (TPU) film was then attached to the composite woven fabrics, forming the BC/SS/TPU composite woven fabrics. Tests of electromagnetic shielding effectiveness (EMSE), far-infrared emissivity, anions, water resistance, and water vapor permeability measured the single-layer, two-layer and four-layer composite woven fabrics, obtaining a far-infrared emissivity of 0.95 by 39.8 counts per minute, an anion count of 149 amount/cc, an EMSE of −11.87 dB under frequency of 900 MHz, a surface resistivity of 8×10⁻⁶ Ω/square, a water resistance of −8219 mmH₂O, and water vapor permeability of 989 g/m²·h and 319 g/m²·24 h in accordance with JIS L 1099 A1 and ASTM E96 BW.     

Ramie (Boehmeria nivea (L.) Gaud.) and Spanish Broom (Spartium junceum L.) fibres for composite materials: agronomical aspects,morphology and mechanical properties

The agronomic characteristics of Ramie and Spanish Broom were investigated for seven years in the pedoclimatic conditions of Central Italy. The chemical, physical and mechanical properties of these fibres were also examined in order to evaluate the feasibility to use them in composite materials. Results demonstrate that Ramie grown in the temperate environment can be harvested three times a year. The yield of green Ramie plants per annum was almost 10 000 g m⁻². The fresh Ramie plant is composed, by weight, of 30% green leaves and 70% green stems. The yield dry fibre is almost 3% of the green stems, giving a total yield of 200 g m⁻². Spanish Broom can reach a fresh biomass yield of 4000 g m⁻² per annum, represented by 53% of long slender terete green branches which constitutes the economic products. The dry yield per annum was about 1800 g m⁻² with a dry branchlets yield of 900 g m⁻². Ramie and Spanish Broom cortical fibres are multiple elementary fibres (ultimates) arranged in bundles. In Ramie, the elementary fibres are bound by gums and pectins, while in Spanish Broom they are bound together by lignin. Both species showed a thick secondary cell wall indicating a high cellulose content. Ramie ultimate fibres are flattened and irregular in shape, while those of Spanish Broom are more regular in shape. The diameter of the ultimates varies from 10 to 25 μm in Ramie, while the Spanish Broom ultimates ranges from 5 to 10 μm; the diameter of the whole bundle is about 50 μm for both species. Ramie fibre showed a content of lignin, pentosans and extractives lower than Spanish Broom. Both fibres had a high content of cellulose which, on the base of X-ray analysis, was evaluated to be in excess of 70%. Ramie and Spanish Broom fibres had tensile strength of 950 MPa and 700 MPa, respectively. The elastic moduli were ≈65 and ≈20 GPa, respectively, which well compare with the modulus of E-glass fibres (70–90 GPa). The strength of the fibre-matrix interface was measured using the single filament fragmentation technique and an epoxy resin as the polymer matrix. Values for carbon and glass fibres in the same resin were also measured for comparison. The interface strength for the vegetable fibres was higher than that of carbon and glass, likely due to a mechanical lock mechanism. These values confirm both fibres as potential replacement for man made fibres in composite materials.     

The influence of water jet pressure settings on the structure and absorbency of spunlace nonwoven

Nowadays, the use of nonwovens as absorbent products is increasing. One of the most important methods for the nonwoven production is spunlace. This research evaluates the effect of spunlace nonwoven structures in wicking, water retention, water vapor permeability and porosity structural parameter of nonwoven. Carded webs from polyester fibers and viscous fibers of four different basis weights (35, 40, 45, and 50 g/m²) were hydroentangled using three different water jet pressures (50, 60, and 70 bar). To study the effect of these variables on the structure of nonwovens and absorbency related properties, sample’s characteristics such as thickness and mass density were measured. An electrical resistance technique was used to study the liquid penetration into nonwovens. The results showed that with increasing water jet pressure, mass density increased and other parameters like thickness, water retention, water vapor permeability and capillary pore size decreased. Also, it was observed with increasing basis weight, the sample thickness increased. On the other hand, with increasing weight, the amount of water retention, water vapor permeability and porosity structural parameter of nonwoven were reduced. The wicking characteristic of nonwovens using the least jet pressure and weight was the best of all the samples.     

An efficient,simple and facile strategy to synthesize Polypropylene-g-(acrylic acid-co-acrylamide) nonwovens by suspension grafting polymerization and melt-blown technique

An efficient, simple and facile process, i.e., suspension grafting polymerization combined with melt-blown technique, was employed to synthesize Polypropylene-g-(acrylic acid-co-acrylamide) nonwoven fabrics [PP-g-(AA-co-AM) nonwovens]. In this study, the grafting mechanism and the effect of synthesis parameters on grafting percentage (GP) were investigated. The as-synthesized products were characterized by melt flow rate (MFR), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), water contact angle (WCA) and thermalgravimetric analysis (TGA). Besides, the uptake properties of metal ions (i.e., Ba²⁺, Cu²⁺, Ni²⁺, Mg²⁺, Al3+, Ca²⁺) on the PP-g-(AA-co-AM) nonwovens in dynamic condition were studied. Results of FTIR showed that AA and AM were successfully grafted onto the PP surface. The decrease in WCAs of the grafted nonwovens with the increasing GP indicated that (AA-co-AM) side chains existed as the hydrophilic component. TGA results revealed that no significant change in thermal stability was found in grafted PP samples. The synthesis experiments showed that the highest GP was obtained at grafting time 3 h, water 3 ml/g, xylene 15 wt%, benzoyl peroxide 0.5 wt%, AA, AM 30 wt% and AA: AM 1:1, with a GP of 16.7 %, and a grafting efficiency of 67 %. However, MFR measurement and SEM image demonstrated that PP-g-(AA-co-AM) nonwovens with the highest GP showed almost no mechanical strength existed between filaments resulting in the occurrence of deformation and contraction of nonwovens, and breaking up into small pieces. Comprehensively, the optimal GP was 8.7 %, and the corresponding PP-g-(AA-co-AM) nonwovens exhibited higher metal ions uptake capacity than pristine PP nonwovens in the dynamic adsorption process.     

Optimum heat treatment conditions for PAN-based oxidized electrospun nonwovens

In this study, the polyacrylonitrile (PAN)-based precursor was produced by electrospinning for the fabrication of oxidized nanofiber nonwovens. The parameters adopted for the oxidation process were chosen from the thermal analysis results obtained using DSC and TGA. The oxidation temperatures of 270, 300, and 330 oC were selected for heating times of 30, 50, and 70 min at three levels of tension. The variations in yield rate, breaking strength, shrinkage and stiffness of the oxidized PAN-based electrospun nonwovens were examined in this article. The results indicate that the physical properties of electrospun nonwovens were affected by the oxidation conditions. In addition, the limit oxygen index (LOI) was found to increase with increasing heat treatment temperature and time. In addition, the optimum oxidation condition was found to be heating temperature of 300 °C for a duration of 70 min. Under this condition, high-quality PAN-based oxidized electrospun nonwovens were produced with aromatization index (AI) of 62 % and LOI of 44 %.     

不同培肥措施对玉米生长发育及产量的影响

采用半量秸秆还田、全量秸秆还田、农家肥30 m3/hm2、农家肥60 m3/hm2、半量秸秆还田+农家肥30m3/hm2和当地常规施肥方式(对照)处理,研究不同培肥措施对玉米生长发育及产量的影响。结果表明,株高、植株基部周长、单株叶面积和棒三叶叶面积均以农家肥60 m3/hm2处理最高;出苗率以农家肥30 m3/hm2处理最高,全量秸秆还田处理最低;经济产量增加幅度依次为半量秸秆还田+农家肥30 m3/hm2>农家肥60 m3/hm2>农家肥30 m3/hm2>半量秸秆还田>全量秸秆还田。     

PAN-based carbon nanofiber absorbents prepared using electrospinning

This study takes polyacrylonitrile (PAN) as a raw material for PAN-based nanofiber nonwoven prepared using electrospinning. First we construct a thermal-stable process for the fabrication of oxidized nanofiber nonwovens as the precursor. A semi-open high-temperature erect furnace is then used with steam as the activator, through carbonization and activation processes to prepare carbon nanofiber absorbents continuously. The experiment varies the production rate and activator flow rate to prepare carbon nanofiber absorbents. Experimental results show that carbon nanofiber adsorbents are primarily made up of micropores and mesopores, averaging under 20 Å. Given a production rate of 10–20 cm/min with a matching activator feed rate of 120 ml/min, the specific surface area can reach about 1000 m²/g, producing an adsorption ratio of carbon tetrachloride over 200 %.     

Transport properties of layered fabric systems based on electrospun nanofibers

Layered fabric systems with electrospun polyurethane fiber web layered on spunbonded nonwoven were developed to examine the feasibility of developing protective textile materials as barriers to liquid penetration using electrospinning. Barrier performance was evaluated for layered fabric systems, using pesticide mixtures that represent a range of surface tension and viscosity. Air permeability and water vapor transmission were assessed as indications of thermal comfort performance. Protection performance and air/moisture vapor transport properties were compared for layered fabric systems and existing materials for personal protective equipment (PPE). Layered fabric systems with electrospun nanofiber web showed barrier performance in the range between microporous materials and nonwovens used for protective clothing. Layered fabric structures with the web area density of 1.0 and 2.0 g/m² exhibited air permeability higher than most PPE materials currently in use; moisture vapor transport was in a range comparable to nonwovens and typical woven work clothing fabrics. Comparisons of layered fabric systems and currently available PPE materials indicate that barrier/transport properties that may not be attainable with existing PPE materials could be achieved from layered fabric systems with electrospun nanofibrous web.     

Study on melt-blown processing,web structure of polypropylene nonwovens and its BTX adsorption

Petroleum hydrocarbons can have adverse impacts on the environment and human health especially when they exist in the form of emulsion and aqueous solution. Nonwovens prepared by melt-blown method are a potential candidate for the removal of petroleum hydrocarbons. In this study, the processing-structure-oil sorption relationships of the PP (polypropylene) melt-blown nonwovens were investigated. Besides, the kinetics and mechanism of toluene sorption in simulated fire-fighting wastewater on the optimized prepared PP melt-blown nonwovens were studied at the static and dynamic conditions. The results showed that the web structure can be effectively controlled by adjusting the hot air temperature, metering pump speed and distance of collector to die to obtain an average fiber diameter of 3.0-10.5 μm, surface area of 0.5-1.5 m²/g and porosity of 71.0-99.0 %. The sorption capacity for pure BTX medium increased with the decreasing fiber diameter and increasing porosity. The pseudo-second-order kinetic model better fitted the experimental data to describe the sorption of emulsified and dissolved form of toluene at static and dynamic conditions. The toluene sorption can be a combination of adsorption and capillarity, the contribution of which was about 1:14.     

Manufacturing and analyses of wet-laid nonwoven consisting of carboxymethyl cellulose fibers

Carboxymethyl cellulose (CMC) is a cellulose derivative having water-soluble property, biodegradability, and biocompatibility. It has been used in various medical applications as forms of gel, film, membrane, or powder. In this study, composite CMC nonwovens were produced, by a wet-laid nonwoven process, to improve the wet strength of carboxymethyl cellulose nonwovens. Followed by preparing the CMC fibers from cotton fiber, the composite CMC nonwovens composed of CMC fibers and PE/PP bicomponent fibers were manufactured by using 85/15 % v/v of ethanol/water solution as a dispersion medium. Structural analyses of CMC fibers, such as XRD, TGA, FT-IR, and degree of substitution indicated that CMC fibers were successfully produced. The wet strength of CMC nonwoven was dramatically increased by blending with the PE/PP fibers without sacrificing the key properties for wound dressing materials such as liquid absorption, gel blocking and liquid retention. It is expected that the composite CMC nonwovens will be a good candidate for wound dressing materials for mild exudate condition.     

Mechanical and physical properties of puncture-resistance plank made of recycled selvages

Glass woven fabric interlayered nonwovens composed of Nylon 6 staple fibers, recycled Kevlar fibers, and low-T_m polyester fibers are prepared into the glass-interlayer plank. Afterwards, their tensile strength, bursting strength, quasistatic and dynamic puncture resistances are evaluated by changing low-T_m polyester and Kevlar fibers mass fractions. The results show that when comprising 30 wt% of low-T_m polyester fibers and 20 wt% of Kevlar fibers, the composite plank yields the maximum tensile strength, bursting strength, quasi-static and dynamic puncture resistances. The double planks arranged in cross direction have higher quasi-static and dynamic puncture resistances than those oriented in parallel direction. According to stereoscope observations, the quasi-static and dynamic puncture resistances of glass-interlayer plank have different fracture mechanism for resisting against spike penetration. In addition, the bursting strength is proportional to quasistatic puncture resistance.     

Evaluation of the protein quality of rice supplemented with bean or crayfish in rats

Weanling male rats (45–60 g) were used to compare the supplemental effects to rice protein of bean or crayfish protein. Rats were fed various combinations of rice plus bean (B) or crayfish (C) to provide 1.6 g N/100 g of the daily diet for 28-day growth studies and a 7-day N balance period. Five different diets were fed. Six rats were assigned to each diet on the basis of body weight. Combinations of R:B of 80:20 and of R:C of 80:20 produced food intake, weight gain, PER, N intake, digested and retained N; and liver weight values that were comparable. However, increasing C to 30% of the dietary protein led to reduced value for food intake, weight gain, PER, N intake, digested and retained N, BV, NPU, and liver weight when compared with values obtained when B was increased to 30% (P<0.05). The results appear to indicate that, above a certain level of supplementation, brown bean protein is superior to crayfish as a supplement to rice protein.     

SEASONAL PATTERNS OF DIGESTIBLE ORGANIC MATTER AND PROTEIN PRODUCTION FROM GRASSES IN THE NORTH PENNINES

The seasonal pattern of digestible organic matter (DOM) and crude-protein production of Lolium perenne, Cynosurus cristatus, Anthoxanthum odoratum, Festuca ovina and Agrostis stolonifera cut to 3 cm at 6-week intervals was studied at five sites ranging from 49 to 303 m above sea level in north-west Lancashire for the years 1969–70. DOM production declined from 482 g/m² on the lowest site to 220 g/m² on the highest; similarly protein production declined from 142 g/m² to 73 g/m². Small but significant differences in the percentage of crude protein occurred only ia 1970, whereas DOM as a percentage of DM in the various species differed considerably between sites in both years. The significance of the results and the seasonal fluctuations in production are discussed.     

Photocatalytic degradation of formaldehyde by silk mask paper loading nanometer titanium dioxide

Silk mask paper with different adsorbability was prepared by changing the beating degree of silk pulp and the basis weight of silk paper, and photocatalytic silk mask paper was prepared by loading nanometer titanium dioxide (nano-TiO₂) on the silk mask paper, then degradation of formaldehyde by silk mask paper loading nano-TiO₂ under daylight lamps and ultraviolet lamps were investigated, respectively. Results showed that silk mask paper could adsorb formaldehyde and had higher adsorption efficiency in the initial stage, and the adsorption/desorption equilibrium could be basically achieved in 60 minutes. The adsorption capacity of silk mask paper made from silk pulp with beating degree of 45 ^oSR was relatively low, and it increased with the increase of beating degree, but there was little change in adsorption when the beating degree of silk pulp exceeded 65 ^oSR. Under daylight lamps, 26.61 %, 31.42 % and 38.21 % of formaldehyde could be degraded in 180 minutes by silk mask paper loading 1 wt%, 3 wt% and 5 wt% nano-TiO₂, respectively. However, under ultraviolet (UV) lamps, 46.23 %, 55.47 % and 66.38 % of formaldehyde could be degraded within the same time, respectively. More formaldehyde could be degraded by photocatalytic silk mask paper under UV lamps than under daylight lamps, and the more the load of nano-TiO₂ on the silk mask paper, the higher the degradation rate of formaldehyde within the same time.     

Three-layer composite filter media containing electrospun polyimide nanofibers for the removal of fine particles

Polyimide (P84) nanofibers of 200-500 nm were deposited uniformly on needle punched aramid felt with basis weight of 260-350 g/m² by optimized electrospinning. High temperature adhesive was then electro-sprayed on the nanofiber side deliberately to bind a thin protective layer made of temperature-resistant non-wovens. The three layer structure was afterwards enforced by hot pressing to form composite filter media. The application of the adhesive was tailored not to affect the permeability of the substrate felt while exerting adhesion strength of over 1000 kPa for the media to be suitable for flue gas dust treatment under 240 ºC. When 0.3-10 μm NaCl aerosols were used as the simulated dusts, it was found that even a small amount of P84 nanofibers could obviously elevate the filtration efficiency. The composite showed 100 % removal efficiency of particles equal and greater than 2.0 μm, and 99.5 % for particles 1.0-2.0 μm in diameter.     

Effect of mercerization on mechanical, thermal and degradation characteristics of jute fabric-reinforced polypropylene composites

Jute fabric reinforced polypropylene composites were fabricated by compression molding technique. Fiber content in the composites was optimized at 45 % by weight of fiber by evaluating the mechanical parameters such as tensile strength, tensile modulus, bending strength, bending modulus. Surface treatment of jute fabrics was carried out by mercerizing jute fabrics with aqueous solutions of NaOH (5, 10 and 20 %) at different soaking times (30, 60 and 90 mins) and temperatures (0, 30 and 70 °C). The effect of mercerization on weight and dimension of jute fabrics was studied. Mechanical properties of mercerized jute-PP composites were measured and found highest at 20 % NaOH at 0 °C for 60 min soaking time. Thermal analytical data from thermogravimetric and differential thermal analysis showed that mercerized jute-PP composite achieved higher thermal stability compared to PP, jute fabrics and control composite. Degradation characteristics of the composites were studied in soil, water and simulated weathering conditions. Water uptake of the composites was also investigated.     

Preparation and Characterization of A Semi-interpenetrating Network Alkaline Anion Exchange Membrane

A series of semi-interpenetrating network (semi-IPN) anion exchange membranes (QCS/St-G_8-2-8, Quaternized chitosan/styrene-[maleic alkylene group diethyl bis (octyl dimethyl chloro/bromide), abbreviated as G_8-2-8] were prepared via in-situ polymerization by Styrene (St) and G_8-2-8 in QCS casting solution. During the process of in-situ polymerization, linear block polymers (St-G_8-2-8) of Styrene and G_8-2-8 was constructed, then was mixed with QCS casting solution, followed crosslinking the QCS by glutaraldehyde (GA). With the increasing content of linear block polymer, water uptake and swelling ratio of the composite membrane decreased; This kind of linear structure makes an order arrangement of quaternary ammonium groups which improves the OH? migration efficiency. At 70 °C, the M-30 composite membrane performs a high OH? conductivity of 8.20×10^-2 S·cm^-1, the methanol permeability is 3.23×10^-6 cm^-2·s^-1 which is still lower than Nafion 115 of 2.42×10^-6 cm^-2·s^-1, but M-30 shows a higher selectivity of 25.3 than Nafion 115 of 11.6. Furthermore, the membranes exhibited excellent thermal stability (≥150 °C), the tensile strength of the composite membrane is in the range of 14-25 MPa and elongation at break is in the range of 16-37 % at room temperature, as well as superior chemical stability in 1.0 M KOH solution for 250 h.     

Physical Quality and Carotene Content of Solar-Dried Green Leafy and Yellow Succulent Vegetables

The effects of vegetable type, vegetable dimensions, and solar drier load on dehydration rate; and texture, color, water activity, and carotene content of solar-dried carrots, sweet potatoes, and collard greens were studied. Mean dehydration rates (moisture loss,%/hr) for solar dried loads of 430 g/m² and 715 g/m² were 3.3 ± 0.30% and 3.8 ± 0.20% for carrots and sweet potatoes, respectively. Loads of 360 g/m² and 465 g/m² of collard greens had dehydration rates of 6.3 ± 0.10% moisture loss per hr. The results showed that vegetable type accounted for significant differences (p < 0.01) in dehydration rate, and beta-carotene content. Vegetable dimensions affected (p < 0.05) water activity. Solar drier load affected water activity (p < 0.01), and hue angle (p < 0.05). Beta-carotene contents (dry basis) of dehydrated carrot, sweet potato, and collard treatments were 10.9–17.4%, 7.6–9.8%, and 11.9–21.5%, respectively. Among the carrot treatments, the 5-mm thick slices packed at a load of 715 g/m² contained the highest beta-carotene (17.4%, dry basis) and vitamin A activity (362 IU/g, dry basis), and good physical properties. For collard greens, the 2-cm and 3-cm wide strips packed at 360 g/m² loads had the best combinations of high beta-carotene (21.5% and 17.2%, dry basis, respectively), vitamin A activity (357.2 and 293.1 IU/g, dry basis, respectively), and optimal color, texture, and water activity. Beta-carotene losses due to solar dehydration were 48.9–67.5%, 4.0–5.8%, and 1.9–19.8% (dry basis) in carrots, sweet potato and collard greens, respectively.     

Fabrication of oxidized sodium carboxymethylcellulose from viscose fibers and their viscosity behaviors

The oxidized sodium carboxymethylcellulose (O-CMC) fibers have been successfully synthesized via the oxidation-etherification method. Subsequently, the O-CMC fibers are characterized by Fourier transform infrared (FT-IR), ¹³C nuclear magnetic resonance (¹³C-NMR) and X-ray diffraction (XRD). In addition, the viscosity behaviors of the O-CMC aqueous solution have been investigated at five temperatures (25, 30, 40, 50 and 60 °C), six concentrations (30, 35, 40, 45, 50 and 60 kg/m³) and four shear rates (6, 12, 30 and 60 rpm). The results show that the viscosity of the O-CMC aqueous solution increases with increasing concentrations and decreases with increasing temperature. The viscosity of the O-CMC aqueous solution is found to exhibit a dilatant behavior. The dissolution rate in water of the O-CMC fibers is faster than that of the carboxymethylcellulose (CMC) fibers. It could be used as novel absorbable hemostatic fibers in surgery.