Modacrylic Fibers Research Articles

Evaluation of the performance properties of modacrylic-cotton blended underwear fabrics manufactured for firefighters

In this study, the mechanical, comfort and flame-retardant properties of different knitted fabric structures containing modacrylic fibers with different blend ratios were investigated. Single jersey, rib, pique, three-thread fleece and interlock fabrics were produced with modacrylic/cotton blended yarns and evaluated comparatively. In order to understand the effect of antistatic fiber content on the investigated properties, two fabrics with antistatic fiber were produced. Since modacrylic fibers have moderate abrasion resistance, pilling resistances of the fabrics are not excellent. Due to the knitted fabrics having a soft and flexible structure, their fabric stiffness and bursting strength are quite high. It has been determined that water vapor resistances of all fabrics are satisfactory and the moisture management properties of the S1 (60% modacrylic, 40% cotton) and R1 (60% modacrylic, 40% cotton) fabrics are excellent. All the fabrics passed the flame-retardancy tests and it is sufficient that the modacrylic ratio is between 50% and 60% according to the fabric structure. Results also showed that 2% antistatic fiber content had no effect on the mechanical, thermal comfort and flame-retardancy properties. Since the air permeability, water vapor resistance and moisture management properties of S1 and R1 specimens are good enough, it is recommended to use one of them according to different temperature conditions. Evaluation of modacrylic fiber blended fabrics in different knitting types in terms of mechanical strength, thermal comfort and flame resistance properties together constitutes the originality of the work. Thus, it was possible to evaluate the effect of different knitting types and contents on all tests.

Quality of Fine Yarns from Modacrylic/Polyacrylate/Lyocell Blends Intended for Affordable Flame-Resistant Underwear.

Flammability testing of undergarments is a topic that is often overlooked and rarely on the list of textiles to be tested for fire safety. However, it is particularly important for professionals exposed to fire risk to investigate the flammability of underwear as its direct contact with the skin can be critical to the extent and degree of skin burns. This research focuses on the suitability of affordable blends of 55 wt.% modacrylic, 15 wt.% polyacrylate, and 30 wt.% lyocell fibres that have the potential to be used for flame-resistant underwear. The influence of modacrylic fibre linear density (standard and microfibres), ring spinning processes (conventional, Sirospun, and compact), and knitted structure (plain, 2:1 rib, 2:1 tuck rib, single pique, and triple tuck) on their properties required for thermal comfort in high-temperature environments was investigated. Scanning electron and optical microscopy, FT-IR spectroscopy, mechanical testing, moisture regain, water sorption, wettability, absorption, DSC, TGA, and flammability were tested to assess the desired suitability. The wetting time (5-14.6 s) and water absorption time (4.6-21.4 s) of the knitted fabrics have shown excellent ability to transport and absorb water compared to the knitted fabrics created from a conventional blend of 65% modacrylic and 35% cotton fibres. The afterflame and afterglow times of less than 2 s met the criteria for non-flammability of the knitted fabrics according to the limited flame spread test method. The results show that the investigated blends have the potential to be used for affordable flame-retardant and thermally comfortable knitted fabrics for underwear.

Thermal, mechanical and comfort performance of various modacrylic fibre blended fabric

In this study, various blended fabrics of modacrylic fibre with flame retardant (FR) viscose, and Nylon 66 have been manufactured and studied for their thermal, mechanical and comfort properties for workers of oil & gas industry. The ring spinning system is used to manufacture three sets of yarns. In the first set, three yarns are produced using only modacrylic, only FR viscose, and only Nylon 66 fibres. The second set of yarns is made using blends of FR viscose and modacrylic. These fibres are blended in three different ratios of 30:70, 50:50 and 70:30 for making yarns. The third set is made out of tertiary blends of FR viscose, nylon 66 and modacrylic. These are blended in two different ratios of 30:20:50 and 50:20:30 respectively. Fabric samples have been produced out of these yarns and evaluated for their flame, thermal and mechanical properties after 5 and 50 washes. The radiant heat transfer index and convective heat transfer index of blends of modacrylic fibre are found in the range 12 - 13.5 s and 5.0 - 5.7 s respectively. Multivariate test analysis has been applied to find out the effect of different fibre blends on various flame and thermal properties. The study shows that flame and thermal resistant properties are influenced by fibre blending ratio.

Synthesis of fluorescent cationic coumarin dyes with rigid molecular structures to improve lightfastness and their related modacrylic dyed fibers

In this study, three novel cationic, fluorescent, coumarin dyes (6a, 6b and 6c) with rigid molecular structures were synthesized and characterized by spectroscopic studies. The photochemical behavior (UV light) of these dyes was studied in ethanol and DMF solvents. Compared to that of a commercial dye (basic yellow-40), the synthesized dyes exhibited good photostability in these solvents. A dyeing experiment was performed on modacrylic fibers with these dyes using a traditional cationic dyeing process. The effect of pH on the absorption spectra and dye bath exhaustion were also studied. The dyeing results showed that all the dyes exhibited obvious fluorescence effects. Based on the luminance factor (β), and photostability behavior, the synthesized dyes can hopefully be applied in high-visibility, fluorescent, yellow warning textiles with improved lightfastness.

Evaluation of Infrared Absorption on Thermal Properties of Modified Modacrylic Fibers

A novel modacrylic fiber with the capability to absorb ∼80% of all infrared radiation was evaluated for use in personal thermal comfort applications. Using an infrared (IR) imaging camera to monitor optical changes over time and heat flux measurements, it was concluded that this altered modacrylic fiber possesses both a unique thermal signature as well as increased heat flux compared to 100% cotton. A design of experiments (DOE) was conducted to determine if blending this material with other fibers would result in a fabric with a higher thermal conductivity. It was observed that blends of nylon and the altered modacrylic tended to have the highest conductivity and would provide a cooling effect if used in a garment.

Properties of Modacrylic Fibers Prepared from Poly(acrylonitrile-co-vinylchloride)—Experimental and Theoretical Studies on Coagulation and Diffusion during Wet Spinning

In this study, we investigated the changes in the morphology, crystal structure, and mechanical properties of poly(acrylonitrile- co-vinylchloride) under various spinning conditions such as distance and concentration of coagulation bath and draw ratio. In addition, the diffusion rate of the solvent from the fiber during coagulation was studied to investigate the correlation between the properties of spun fiber and coagulation conditions. The mechanical properties and the crystal orientation were improved with the draw ratio at a constant concentration of the coagulation bath. Micro voids were decreased with increased initial dimethyl sulfoxide (DMSO) concentration in the coagulation bath at a constant temperature. In addition, the correlation between the spun fiber and its spinning conditions during the coagulation process was determined, leading to optimal spinning conditions.

Flame-Retardant and Wear Comfort Properties of Modacrylic/FR-Rayon/Anti-static PET Blend Yarns and Their Woven Fabrics for Clothing

This study examined the flame retardant, anti-static, and wear comfort properties of woven fabrics from two types of yarns composed of modacrylic, FR-rayon, cotton, and anti-static PET fibers. The FR-rayon-blended modacrylic fabric mixed with anti-static PET fibers exhibited better flame-retardant and anti-static properties than those of the cotton-blended modacrylic fabric. In addition, the absorption and drying properties of the FR-rayon-blended modacrylic fabric were superior to those of the cotton-blended modacrylic fabric. The thermal conductivity of the FR-rayon-blended fabric was lower than that of the cotton-blended one, whereas the water vapor permeability was slightly higher than that of the cotton-blended one. These wear comfort properties of the FR-rayon-blended fabric were attributed to the micro-pores and longer fiber length of the FR-rayon fibers, as well as their yarn and fabric structural parameters. This study suggests that FR-rayon-blended modacrylic fabric has better flame-retardant and anti-static properties in both twill and rip weaves with good warmth keepability, and higher water and vapor transmission properties than cotton-blended one. In addition, the FR-rayon-blended modacrylic clothing exhibited a better wear comfort feel than the cotton-blended one due to the lower microclimate humidity. This means that FR-rayon-blended modacrylic fabric makes it more comfortable to wear than cotton-blended one.

The relationship between cross-sectional shapes and FTIR profiles in synthetic wig fibers and their discriminating abilities — An evidential value perspective

Wig fragments or fibers may occasionally be recognized as potential physical evidence during criminal investigations. While analytical methods traditionally adopted for the examination of textile fibers are utilized for the characterizations and comparisons of wig specimens, it is essential to understand in deeper detail the valuable contribution of features of these non-routine evidentiary materials as well as the relationship of the gathered analytical data. This study explores the dependence between the microscopic features of cross-sectional shapes and the polymer type gathered by Fourier transform infrared (FTIR) spectroscopy. The discriminating power of the two methods of cross-sectioning and FTIR spectroscopy was also investigated. Forty-one synthetic wigs varying in both quality and price were collected: twenty-three brown, twelve blondes and six black samples. The collected samples were observed using light microscopy methods (bright field illumination and polarized light), before obtaining cross-sections using the Joliff method and analyze them using FTIR spectroscopy. The forty-one samples were divided into ten groups based on one or more of the ten types of cross-sectional shapes that were observed. The majority of encountered cross-sectional shapes were defined as horseshoe, dog bone and lobular. Infrared spectroscopy confirmed modacrylic to be the most prevalent fiber type. Blends of modacrylic and polyvinyl chloride fibers were also observed as well as polypropylene wig samples. The Goodman and Kruskal lambda statistical test was used and showed that the cross-sectional shape and infrared profile were related. From an evidentiary value perspective, this finding has implications when addressing questions about a common source between questioned wig specimens and a wig reference sample.

Modacrylic anion-exchange fibers for Cr(VI) removal from chromium-plating rinse water in batch and flow-through column experiments

ABSTRACTThe aim of this study was to investigate Cr(VI) removal from chromium-plating rinse water using modacrylic anion-exchange fibers (KaracaronTM KC31). Batch experiments were performed with synthetic Cr(VI) solutions to characterize the KC31 fibers in Cr(VI) removal. Cr(VI) removal by the fibers was affected by solution pH; the Cr(VI) removal capacity was the highest at pH 2 and decreased gradually with a pH increase from 2 to 12. In regeneration and reuse experiments, the Cr(VI) removal capacity remained above 37.0 mg g−1 over five adsorption–desorption cycles, demonstrating that the fibers could be successfully regenerated with NaCl solution and reused. The maximum Cr(VI) removal capacity was determined to be 250.3 mg g−1 from the Langmuir model. In Fourier-transform infrared spectra, a Cr = O peak newly appeared at 897 cm−1 after Cr(VI) removal, whereas a Cr–O peak was detected at 772 cm−1 due to the association of Cr(VI) ions with ion-exchange sites. X-ray photoelectron spectroscopy analyses demonstrated that Cr(VI) was partially reduced to Cr(III) after the ion exchange on the surfaces of the fibers. Batch experiments with chromium-plating rinse water (Cr(VI) concentration = 1178.8 mg L−1) showed that the fibers had a Cr(VI) removal capacity of 28.1–186.4 mg g−1 under the given conditions (fiber dose = 1–10 g L−1). Column experiments (column length = 10 cm, inner diameter = 2.5 cm) were conducted to examine Cr(VI) removal from chromium-plating rinse water by the fibers under flow-through column conditions. The Cr(VI) removal capacities for the fibers at flow rates of 0.5 and 1.0 mL min−1 were 214.8 and 171.5 mg g−1, respectively. This study demonstrates that KC31 fibers are effective in the removal of Cr(VI) ions from chromium-plating rinse water.

Thermochemical Approach for Screening of Alternative Metal Oxides as a Flame Retardant of Modacrylic Fiber

AbstractIn the view of the exploring novel flame retardants for polymers, modacrylic fibers, which consist of acrylonitrile and vinylidene dichloride, containing metal oxide have been investigated by thermogravimetric–mass spectrometry (TG-MS) analysis. It was found that, among the examined oxides, germanium and antimony oxides formed the corresponding volatile chlorides through the reactions of oxides with hydrogen chloride formed during thermal decomposition of the polymer. The results have been discussed in the framework of thermochemistry. Based on the equilibrium calculation of the polymer–oxide mixture, the predominance diagrams of the M-O-Cl systems (M = Sb and Ge) show that the chlorides are the most stable phases at 573 K, at which temperature the major decomposition of the polymer starts. These results suggest that GeO2 would be a possible candidate of a flame retardant for chlorinated polymers. However, combustion experiments revealed an insufficient performance of the oxide. The inductively coupled plasma with atomic emission spectroscopy (ICP-AES) analysis showed the reactivity of GeO2 for HCl was inferior to that of Sb2O3, and X-ray fluorescence spectrometer (XRF) analysis of the solid thermal decomposition products showed that the evaporation of germanium was less intense than that of the conventional antimony system. This result is presumably due to the smaller rate of the chlorination of GeO2 than that of Sb2O3.

Flame retardancy in fabric consisting of cellulosic fiber and modacrylic fiber containing fine‐grained MoO3 particles

SummaryFlame retardancy of fabrics consisting of modacrylic fiber containing with various dispersed metal compounds and cellulosic fiber has been investigated by means of flame test (ISO15025 procedure A) and limiting oxygen index (LOI). It has been found that excellent flame retardancy is achieved by fine‐grained MoO3 particles. The afterflame time in flame test and the LOI value are improved with decreasing particle size of MoO3. The flame retardancy of MoO3 (particle size; 0.1 µm) is comparable to that of Sb2O3. On the other hand, significant improvement in flame retardancy is not observed for other metal compounds although some metal oxides and a hydroxide in the present study are known as flame retardant or smoke suppressing agent in halogen containing polymer in previous studies. In order to clarify the mechanism of the observed flame retardancy by the addition of fine‐grained MoO3, we have carried out X‐ray fluorescence spectrometry (XRF) measurement of the fabric specimen after the flame test and thermogravimetric analysis (TGA) of various types of samples. These analytical data indicated that MoO3 works as halogen synergist in solid phase and the char of modacrylic fiber formed by addition of MoO3 suppresses decomposition of the cotton blended in the fabric in the range of the ignition temperature. Copyright © 2015 John Wiley & Sons, Ltd.

Innovative Fire- and Heat-Protective Knit Fabrics and Individual Protective Aids

The properties of fire- and heat-protective knit fabrics and individual protective aids, such as underand winter-wears, helmet liners, helmet guards, gloves, socks, etc., are studied. Knit fabrics and individual protective aids are developed using blended yarn comprised of fire-resistant modacrylic fibre Protex (55%) and cotton fibre (45%) and fire-resistant meta-aramid yarn. The special properties of the articles are studied at Scientific and Production Limited Liability Company Armokom-Tsentr with due regard for their performance conditions with respect to such parameters as resistance to open flame, heat insulating capacity, heat resistance, etc. It is demonstrated that the under- and winter-wears are resistant to open flame (no inflammation, residual burning, or smoldering, but destruction of the fabric is noticed). In terms of heat insulating capacity, these clothes meet the technical specifications in conformity with heat insulation standard GOST (Russian State Standard) 29104.14. Helmet liners and helmet guards are resistant to open flame (no inflammation, residual burning, or smoldering, but destruction of the fabric is noticed). The heat insulating capacity of these articles meets technical specifications. The performance properties of fire- and heat-protective gloves conform to GOST 12.4,246 and of socks, to GOST 8541. The gloves are resistant to open flame and are not destroyed, which make them usable without additional protection. The socks developed are resistant to open flame, have high heat insulating capacity, and are comfortable to use.

Vpliv dodanih vlaken MAC in MTF v mešanici na mehanske lastnosti prstanske preje za varovalne tekstilije

Vpliv dodanih vlaken MAC in MTF v mešanici na mehanske lastnosti prstanske preje za varovalne tekstilije

A Simple Solubility Tests for the Discrimination of Acrylic and Modacrylic Fibers

In a crime scene investigation, single fibers play an important role as significant trace physical evidence. Acrylic fibers are frequently encountered in forensic analysis. Currently, acrylic and modacrylic are not discriminated clearly in Japan. Only results of FT-IR, some of acrylics were difficult to separate clearly to acrylic and modacrylic fibers. Solubility test is primitive but convenient useful method, and Japan Industrial Standards (JIS) recommends FT-IR and solubility test to distinguish acrylic and modacrylic fibers. But recommended JIS dissolving test using 100% N,N-dimethylformamide (DMF) as a solvent, some acrylics could not be discriminated. In this report, we used DMF and ethanol (90:10, v/v) solvent. The JIS method could not discriminate 6 acrylics in 60 acrylics; hence, DMF and ethanol (90:10, v/v) solvent discriminated 59 of the 60 fibers (43 acrylic and 16 modacrylic fibers) clearly, but only one modacrylic fiber incorrectly identified as acrylic.

Establishment of quantification methods for novel polypropylene/polyamide 6-based bicomponent fibre in textile binary mixtures

The aim of this study was the establishment of quantification methods for binary mixtures containing a novel polypropylene/polyamide 6-based bicomponent fibre, for which a new generic fibre name has been requested to the European Commission. Application of such methods is requested by EU legislation to enable market surveillance of the compulsorycomposition labelling of textile products. Evaluating the key parameters for quantification, results showed that the b coefficient for the novel fibre (mass loss due to normal pre-treatment) is equal to 0%. In agreement with the members of the European Network of National Experts on Textile Labelling, the value of 1.00% was established as its agreed allowance (moisture regain in standard atmosphere), on the basis of the experimental value of 0.54%. Among the dissolution methods described in Directive 96/73/EC, the new fibre was insoluble in ten, for which the d correction factors (mass loss of the insoluble component) were evaluated. Three of them were additionally validated through an EU collaborative trial according to ISO 5725:1994. The ten established d correction factors were in the range of 1.00–1.01, revealing complete insolubility or up to 1% solubility of the novel fibre in the dissolution reagents. Based on this study, laboratories now have at their disposal methods to quantify the new fibre in binary mixtures with polyester, elastomultiester, polyamide, chlorofibres, certain acrylic and modacrylic fibres, acetate, triacetate, polylactide, certain cellulose fibres and certain protein fibres.

Acid–base properties of ion exchangers: V. Synthesis and properties of ion exchangers on the base of modacrylic polyacrylonitrile–vinylchloride fibers

Weak base polyfunctional fibrous anion exchangers, containing small amount of carboxylic acid groups were obtained on the base of industrial modacrylic fibers Kanecaron (40% acrylonitrile, 60% vinylchloride) (Kaneka Ltd., Japan) by their reacting with aqueous solutions of diethylenetriamine (DETA). The sample obtained at optimal condition (DETA concentration 70–80%, process time 2–7 h, temperature 95 °С) have anion exchange capacity 3–5 meq/g and water uptake 0.3–0.4 gH 2O/g. Their chemical stability in different media has been studied. On the base of studies of their ion exchange capacity, elemental analysis, potentiometric titration and IR spectra the structure of these ion exchangers has been clarified. Predominant reaction of the modification is substitution of the Cl atoms by nitrogen in DETA molecules with formation of tertiary and secondary amino groups. All three atoms of nitrogen react and the ratio of incoming N atoms and outgoing Cl atoms is close to one.

Conductive ceramic coating on polyacrylonitrile–vinyl chloride (modacrylic) discontinuous fibers via electroless deposition

Lead dioxide has electrical conductivity that is comparable to that of some of the metals. As a result like copper and nickel, lead dioxide can be deposited on non-conducting materials like polymers and ceramics using spontaneous and low cost deposition technique such as electroless deposition. This paper deals with development of conductive modacrylic fibers by coating them with lead dioxide via electroless deposition. The fibers so obtained will be used as additive in the lead-acid battery to improve its life and specific energy.

Radiant Protective and Transport Properties of Fabrics Used by Wildland Firefighters

The radiant protective performance, thermal resistance, air permeability, and moisture evaporation of a series of fabrics made from aramid, modacrylic, polyimide, and fire resistant cotton fibers are evaluated in the laboratory. The radiant protective performance of single-layer fabrics is affected by the structure, weight, thickness, and materials, consistent with the thermal protective performance of fabrics previously discussed. A fabric's transport properties, which are closely associated with comfort performance, can be reflected by a combination of its air permeability, thermal resistance, and moisture evaporation, which are also governed by the same structural factors. Thus, it is our intention to explore the relationship between fabric structures and both radiant protective and transport properties so that we can provide the necessary information for selecting appropriate fabrics for firefighter's uniforms.

Is it a modacrylic fibre?

This study describes the characteristics of modacrylic fibres and includes over 80 samples (previous and current) representing 15 trade names. Fibre morphology was examined using brightfield microscopy. Signs of elongation were determined using polarised light microscopy. Fibre cross sections were also examined. The generic class of fibre was divided into sub groups using polymer composition as determined by FTIR-microscopy. Microscopically, some modacrylic fibres cannot be distinguished from acrylic fibres. Others display unusual optical and morphological features which are a strong indication of their generic class. The infrared spectra provide information about the co-monomer, termonomers added to produced dye sites, the presence of solvent residue, dyes, and additives, e.g. flame retardant material. The infrared spectra should always be recorded before and after any thin layer chromatographic examination of the dye, otherwise peaks attributable to dyes, which may be a valuable comparative feature in casework will be lost.

Flat-like acrylic and modacrylic fibres

Flat-like acrylic and modacrylic fibres