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1.
To develop reusable incontinence products, blend nonwovens of hollow viscose rayon (HVR) and super absorbent fibers (SAFs) were prepared using a needle-punching process and their liquid handling properties, such as the fluid absorption capacity, fluid retention capacity, fluid absorption under load, moisture evaporation rate, and repeated water absorption were investigated. As the SAF content in the HVR/SAF blend nonwovens was increased, the fluid absorption capacity, fluid retention capacity, and fluid absorption under load increased, whereas the moisture evaporation rate decreased. SAF had a more significant effect on fluid retention than fluid absorption. In the case of HVR/SAF(8/2) and HVR/SAF(7/3), more than 100 % of the fluid absorption capacity was retained even after 5 cycles of repeated water absorption tests. Overall, the HVR/SAF blend nonwovens are good candidates for reusable incontinence products. 相似文献
2.
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. 相似文献
3.
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. 相似文献
4.
Fabrication of long and discontinuous natural fiber reinforced polypropylene biocomposites and their mechanical properties 总被引：1，自引：0，他引：1
Natural fiber reinforced polypropylene (PP) biocomposites were fabricated by blending long-and-discontinuous (LD) natural
fibers (NF) with LD PP fibers. Firstly, random fiber mats were prepared by mixing NFs and PP fibers using a carding process.
Then, heat and pressure were applied to the mats, such that the PP fibers dispersed in the mats melted and flowed out, resulting
in the formation of consolidated sheets upon subsequent cooling. The effect of the fiber volume fraction on the mechanical
properties of the bio-composites was scrutinized by carrying out tensile and flexural tests and observing the interface between
the fiber and matrix. It was observed that the natural LD fiber content needs to be maintained at less than the nominal fiber
fraction of 40 % by weight for the composites fabricated using the current method, which is quite low compared to that of
continuous or short fiber reinforced composites. The limited fiber fraction can be explained by the void content in the biocomposites,
which may be caused by the non-uniform packing or the deficiency of the matrix PP fibers. 相似文献
5.
Raw Jute was modified by acetylation process with acetic anhydride using N-bromosuccinimide (NBS) as a catalyst in a solvent free system which was found to be effective catalyst. The reaction parameters were optimized which were found to be time 1 h, temperature 120 °C, catalyst concentration 2 %, and solid to liquid ratio 1:20. The product so formed was characterized by FT-IR and TG and its degree of acetylation was also evaluated. The extent of acetylation was measured by weight percent gain (WPG). Acetylation resulted in significant increase in hydrophobic properties of the jute fiber. The oil sorption capacity of the acetylated jute was higher than that of the commercial synthetic oil sorbents such as polypropylene fibers as well as raw jute. Therefore, these oil sorption-active materials which are also biodegradable can be used to substitute non-biodegradable synthetic materials in oil spill cleanup. 相似文献
6.
A novel biodegradable material derived from thermoplastic potato starch was prepared with intended uses in high moisture environments where its high water sorption characteristics are beneficial, such as wound dressing, transdermal patches or food packaging. A modified composite was prepared for this purpose by reactive extrusion whereby potato starch and 2.5-25% (w/w) sisal cellulose fibers were compounded together in the presence of 2.7% (w/w) sodium trimetaphosphate. The fibers were included to increase the wet strength of the material. A low degree of substitution (0.088-0.113) was sought by bound phosphate groups with anionic character in order to overcome a reduction in moisture absorption capacity resulting from fiber incorporation, yet being insufficient to cause embrittlement via crosslinking. The results showed the approach has sufficient merit to minimize the influence of the hydrophobic fibers on the water absorption capacity of the starch material but adhering to so low of a degree of substitution could not fully prevent a reduction. The results also suggested that the fibers may have participated in the crosslinking reaction. 相似文献
7.
8.
As a widely applied polymer, hydrophilic modification of polypropylene (PP) has been an important research field. Forcespinning? uses centrifugal force to fabricate nanofibers rather than electrostatic force as in conventional electrospinning. The absence of electric fields provides a board opportunity for low dielectric materials and the utilization of centrifugal forces significantly increases the yield compared to electrospinning. Hydrophilic nonwovens from isotactic polypropylene (iPP) melt blended with amphihilic surfactant TWEEN20 and TWEEN60 were obtained by Forcespinning?. The factors were investigated by SEM and DSC, which determined fiber diameter distribution and crystallinity. The meshes showed continuous homogeneity along the length of the fiber when the system was employed at 225 °C and the rotational speed at 14,000 rpm. Blending with surfactants bearing ethoxylate groups led to increased oxygen content of the meshes surface as confirmed by ATR-FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). XPS results indicated preferential distribution of additives on surfaces. The forcespun meshes exhibited excellent hygroscopicity even when the load of TWEEN20 was 10 %. 相似文献
9.
Synthetic fibers are generally produced with circular cross sectional shapes. Other cross sectional shaped fibers such as trilobal, triangular, hollow and pentagonal fibers are also produced to improve some properties of fibers and fabrics such as lustre, handle, wicking rate, strength, stiffness and bulkiness. In this research we aimed to investigate compressional behaviours of fabrics knitted from polypropylene fibers having three different cross sectional shapes; namely circular, trilobal and triangular. Morphological, structural and mechanical properties of produced fibers were evaluated by using scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry and tensile tester, respectively. In terms of structural and mechanical properties, no significant differences were found related to fiber cross sectional shapes. Then, plain knitted farbrics were produced and compressional properties of these fabrics were investigated. Fabrics knitted from trilobal fibers showed the highest compressibility properties and it is followed by fabrics which are produced from triangular and circular fibers. 相似文献
10.
Needle-punched nonwovens are widely used in industrial fields. However, they are limited to some applications such as high-efficiency filters, high-performance synthetic leathers, and high-absorption wipes because of their low surface area and large pore size. In this study, needle-punched nonwovens composed of Copolyethylene terephthalate (Co-PET)/Polyamide (PA) sea-island bicomponent fibers were treated in NaOH solution with various conditions for preparing nonwovens composed of ultra-fine fibers. The effect of NaOH concentration and treatment temperature on the structural factors and physical properties of nonwovens was investigated. The morphological structures of Co-PET and PA components were analyzed by scanning electron microscope. After alkali treatment, fiber diameter was significantly reduced from 23.65 to 3.95 μm, specific surface area of nonwovens increased more than five times, calculated and experimental mean pore diameter decreased by 83.6 % and 20.8 %, respectively. By increasing NaOH concentration and treatment temperature, pore diameter was reduced, thereby decreasing the air permeability of nonwovens. Meanwhile, tensile strength increased and tearing strength decreased as NaOH concentration and treatment temperature were increased in both machine and cross direction, respectively. The treatment temperature of alkali treatment was significantly influenced by the physical properties of nonwovens. 相似文献
11.
Needle-punched webs for wet cleaning wipes were produced using a dry-laid method of web- forming. Fibrous webs with a different content of hydrophilic viscose and hydrophobic polyester fibers, as well as webs made from 100 % polyester fibers, were utilized during this study. The webs were compared in terms of their water absorption capacity on the basis of their basic construction parameters, such as fiber fineness, raw material (e.g. fiber density), and web density. The higher water absorption capacity of the viscose/polyester-blended needle-punched webs was achieved at higher content of viscose fibers which coincide with the higher fiber density, finer fibers, and lower web density. A prediction model regarding water absorption capacity of viscose/polyester needle-punched webs was developed on the basis of the mentioned construction parameters and a non-deterministic modelling method, e.g. genetic algorithms, and could provide a guideline for the engineering of nonwoven webs in order to fit the desired water absorption capacity. 相似文献
12.
Following the previous studies regarding blue and yellow dyes, a series of new red dyes having different length of alkyl substituents
on the same chromophore were synthesized in order to dye unmodified polypropylene fiber. The affinity of the dyes onto unmodified
polypropylene fiber was increased with the increase of the length of alkyl substituents. Therefore, the longest hexyl-substituted
dye showed very deep shade of dyeing with K/S value of around 30 at maximum absorption wavelength. Within the range below 2 % o.w.f., the exhaustion (%) showed more than
80 %. The color fastnesses to washing, rubbing, and light of the dyeings were also improved greater for the dyes having longer
alkyl substituents than the shorter ones. Since color hue of the dyes exhibited very strong red, they could be considered
to be used as the primary red color dyes for unmodified polypropylene fibers. 相似文献
13.
The application of Electrostatic Force Microscopy (EFM) was studied in analyzing the corona-charged polypropylene fiber. Electrostatic
force gradient images were obtained from the phase shifts with the varied bias voltages applied to the EFM cantilever by the
noncontact scans. A mathematical expression to model the EFM phase shifts as a function of the applied tip bias voltages was
introduced. EFM analysis was used to test the hypothesis that the solvent-induced efficiency deterioration of electret filter
media originates from charge deterioration. EFM investigation produced evidence that exposure to isopropanol in the liquid
phase affected the electrostatic charges on fibers. Exposure to organic solvents in liquid phase is thought to increase chain
and charge mobility in polypropylene fibers, thereby reducing the electrostatic charge and the particle capture ability. 相似文献
14.
The dyeing properties of hydrophobic polypropylene fibers using cationic dyes were investigated to improve dyeability by electron
beam irradiation and sulfonic acid incorporation. The color strength of polypropylene fibers after irradiation was examined
according to the dyeing conditions including the pH of the dyebath, absorbed doses, and the introduction of a functional group
to the fiber substrate. The best dyeing result was obtained when polypropylene fibers incorporated by sulfonic acid group
after electron beam irradiation were dyed with cationic dyes at alkaline conditions and 30∼75 kGy irradiation ranges. 相似文献
15.
Marija Vukcevic Biljana Pejic Mila Lausevic Ivana Pajic-Lijakovic Mirjana Kostic 《Fibers and Polymers》2014,15(4):687-697
Short hemp fibers, acquired as a waste from textile industry, were used as an efficient biosorbent for removal of zinc ions from polluted water. In order to obtain the material with better sorption properties, short hemp fibers were subjected to oxidative and alkali treatment. The following factors that may influence the sorption properties of short hemp fibers were examined: fiber structure and morphology were characterized by iodine sorption, water retention and scanning electron microscopy, while specific surface area was determined by BET method. Additionally, the amount of carboxyl groups was determined by calcium-acetate method, and the point of zero charge of the short hemp fibers samples was determined by the solid addition method. Biosorption of zinc ions was evaluated through the total uptake capacity, equilibrium and kinetic data. Obtained data were analyzed by nonlinear Langmuir and Freundlich isotherms, as well as pseudo-first and pseudo-second order kinetic models, and the best fitting model was chosen using Akaike information criterion. Chemical modification, used in this work, leads to structural and morphological changes of short hemp fibers, and improvement of their sorption properties. It was found that sorption properties of short hemp fibers are predominantly influenced by surface acidity and the amount of functional groups, while fiber structure and specific surface area have a secondary role in the biosorption of zinc ions. Akakike information criterion values showed that biosorption of zinc ions on all tested hemp fiber samples obey the pseudo-second order adsorption kinetics, while experimental isotherm data fit better with Langmuir model. Biosorption of zinc ions on the hemp fibers is a predominantly chemical process, which mainly follows the mechanism of ion exchange on acidic functional groups, and occurs through the fast surface adsorption, intraparticle diffusion and final equilibrium stage. 相似文献
16.
As PET (Polyester) fiber has better heat resistance than PVC fiber or modacryl fiber, it has been used as wig fiber for human hair alternatives. However, PET is heavier and has higher specific gravity than human hair, and therefore the authors attempted to make lighter wig fiber by blending PP (polypropylene) into PET by mixing the PET/PP blend with a compatibilizer, a ethylene-acrylic ester-GMA(EAG) component grafted material, to overcome poor compatibilities of PET and PP. The thermal properties of the PET/PP blend mixed with EAG were measured using DSC, and the results showed that EAG affected melting point and crystallization temperature of the blend polymer. As blend ratio of PP increased, specific gravity of blend fiber reduced and thermal shrinkage rate increased. Blend ratio of PP was greater for shorter lengths of initial curl, although curl loosening increased as time elapsed. 相似文献
17.
Amirhossein Esfandiari 《Fibers and Polymers》2008,9(1):48-54
A systematic and statistical approach to evaluate and predict the properties of random discontinuous natural fiber reinforced
composites. Different composites based on polypropylene and reinforced with natural fibers have been made and their mechanical
properties are measured together with the distribution of the fiber size and the fiber diameter. The values obtained have
been related to the theoretical predictions, using a combination of the Griffith theory for the effective properties of the
natural fibers and the Halpin-Tsai equation for the elastic modulus of the composites. The relationships between experimental
results and theoretical predictions are statistically analyzed using a probability density function estimation approach based
on neural networks. The results show a more accurate expected value with respect to the traditional statistical function estimation
approach. In order to point out the particular features of natural fibers, the same proposed method is also applied to PP-glass
fiber composites. 相似文献
18.
Dispersion and separation of fiber bundles into individual fibers, requires exposing them to a shear stress field to overcome
inter-fiber frictional forces. To this end, fiber-mixing tanks are usually used to enhance shear and agitation in water and
help the dispersion process. The required time and necessary agitation to separate and disperse fibers depend on fibers’ characteristics.
It is well known that excessive agitation will give rise to the formation of rope defects in the output because of the high-energy
vortices and optimizing the break up time is important in wet-lay process. In this work, experimental and numerical studies
were done to investigate the effects of fiber characteristics on their dispersion in water for wet-laid nonwoven. The effective
forces were analyzed using a one-way modeling of fiber behaviors in a stirred mixing tank. Results show that when the fiber
diameter is increased, the required time for breaking up of fiber bundles and clumps is increased. The effects of fiber types
on fibers break up and dispersing time, were also investigated. In the experimental work, an on-line vision system was designed
to observe the dispersion behavior of polyester fibers. The effects of fiber length and fineness on the created defects (i.e.
logs and ropes) in dispersion process, as well as on the dispersion speed, were studied. The results confirm that defects
are increased by rising fiber length and fineness. It is also shown that increasing fiber length and fineness, decreases the
required time for fiber clumps to be opened and reach a maximum number of individual fibers. On the other hand, when fiber
length and fineness is increased, the dispersion speed increases. 相似文献
19.
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. 相似文献
20.
Yosuke Kadomae Yasuhide Maruyama Masataka Sugimoto Takashi Taniguchi Kiyohito Koyama 《Fibers and Polymers》2009,10(3):275-279
Electrospun atactic polypropylene (PP) fibers are thicker than those obtained from isotactic PP, although the viscosity of
molten PPs is almost same. Thus we focused on the effect of tacticity of PP on fiber diameters. The PP samples with various
tacticity were prepared by changing the blend ratio of isotactic PP and atactic PP. Melt-electrospinning is performed by using
blended samples, and then electrospun fibers were observed by scanning electron microscope to evaluate fiber diameter of obtained
fibers. It is clear that the diameter of electrospun PP fibers decreases as high tacticity content of PP increases. This result
suggests that tacticity of samples is an important factor to control the electrospun fiber diameter. 相似文献