There is a lack of consensus on methods for cotton dust measurement in the textile industry, and techniques vary between countries-relying mostly on cumbersome, traditional approaches. We undertook ...comparisons of standard, gravimetric methods with low-cost optical particle counters for personal and area dust measurements in textile mills in Pakistan.
We included male textile workers from the weaving sections of seven cotton mills in Karachi. We used the Institute of Occupational Medicine (IOM) sampler with a Casella Apex 2 standard pump and the Purple Air (PA-II-SD) for measuring personal exposures to inhalable airborne particles (n = 31). We used the Dylos DC1700 particle counter, in addition to the two above, for area-level measurements (n = 29).
There were no significant correlations between the IOM and PA for personal dust measurements using the original (r = -0.15, P = 0.4) or log-transformed data (r = -0.32, P = 0.07). Similarly, there were no significant correlations when comparing the IOM with either of the particle counters (PA and Dylos) for area dust measurements, using the original (r = -0.07, P = 0.7; r = 0.10, P = 0.6) or log-transformed data (r = -0.09, P = 0.6; r = 0.07, P = 0.7).
Our findings show a lack of correlation between the gravimetric method and the use of particle counters in both personal and area measurements of cotton dust, precluding their use for measuring occupational exposures to airborne dust in textile mills. There continues to be a need to develop low-cost instruments to help textile industries in low- and middle-income countries to perform cotton dust exposure assessment.
Abstract A collaborative study on Raman spectroscopy and microspectrophotometry (MSP) was carried out by members of the ENFSI (European Network of Forensic Science Institutes) European Fibres Group ...(EFG) on different dyed cotton fabrics. The detection limits of the two methods were tested on two cotton sets with a dye concentration ranging from 0.5 to 0.005% (w/w). This survey shows that it is possible to detect the presence of dye in fibres with concentrations below that detectable by the traditional methods of light microscopy and microspectrophotometry (MSP). The MSP detection limit for the dyes used in this study was found to be a concentration of 0.5% (w/w). At this concentration, the fibres appear colourless with light microscopy. Raman spectroscopy clearly shows a higher potential to detect concentrations of dyes as low as 0.05% for the yellow dye RY145 and 0.005% for the blue dye RB221. This detection limit was found to depend both on the chemical composition of the dye itself and on the analytical conditions, particularly the laser wavelength. Furthermore, analysis of binary mixtures of dyes showed that while the minor dye was detected at 1.5% (w/w) (30% of the total dye concentration) using microspectrophotometry, it was detected at a level as low as 0.05% (w/w) (10% of the total dye concentration) using Raman spectroscopy. This work also highlights the importance of a flexible Raman instrument equipped with several lasers at different wavelengths for the analysis of dyed fibres. The operator and the set up of the analytical conditions are also of prime importance in order to obtain high quality spectra. Changing the laser wavelength is important to detect different dyes in a mixture.
In this study, dimensional and some physical properties of plain (single jersey) and lacoste knitted fabrics made from 50/50 modal/combed cotton blended yarns (tex 21 and 15) were investigated. ...Twelve weft knitted fabrics were produced with two different structures and three different densities (loose, medium, tight). For physical properties, the fabric weight per unit area, fabric thickness, bursting strength, air permeability and dimensional stability were evaluated. We focused on the dimensional stability properties of outwear knitted fabrics. The total dimensional change of the fabric’s dimensions and structural properties were measured and evaluated after ten washing cycles and then flat dried. The results show that the weight per unit area, thickness, air permeability and dimensional stability values are independent of the yarn linear density, fabric structure and fabric density. Statistically evaluated using Design Expert Analysis of variance (ANOVA) software 6.06., test results show that dimensional stability is mostly effective for the bursting strength, air permeability and fabric weight per unit area.
The purpose of this study was to evaluate the effect of selective oxidation on the surface properties of cotton cellulose fibres. Four different methods to evaluate the accessibility, nature and ...content of ionisable acidic groups (charge) in the fibres were applied: potentiometric and conductometric titrations, polyelectrolyte adsorption and X-ray photoelectron spectroscopy (XPS). The results from this combination of methods show that two processes take place when the oxidation method is applied: elimination of low molecular mass non-cellulosic compounds and formation of new acidic groups in the cellulose chains. Which of these processes is predominating depends on oxidation time, but the first one is initially more important. Polyelectrolyte adsorption and XPS show that the surface concentration of acidic groups is considerably lower than the bulk concentration, i.e. during oxidation the content of carboxyl groups in the surface region decreases, while it increases in amorphous regions. The decrease is due to the dissolution of low molecular weight compounds; the increase is due to the formation of new acidic groups. The use of titration methods in combination with XPS appears to be a very useful tool for identification of the formation and distribution of ionic groups in cotton fibres and their surfaces.
This paper reports the fabrication of natural, biodegradable, disposable and low cost clothing with antibacterial activity. Chitosan has been successfully immobilized on woven cotton with the help of ...natural rubber latex. The water contact angle studies reveal increased hydrophilicity of the samples with increase in chitosan concentration. The as prepared materials exhibited excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Due to the electrostatic interaction between chitosan and bacterial surface, the chitosan immobilized samples exhibited clear inhibition zones. This study invokes the possibility of fabrication of medical textiles with antibacterial properties by simple processing of woven cotton materials.
Silver nanoparticles were synthesised on the modified cotton fibres using an in situ method. Acrylic acid was grafted on the surface of cotton using plasma technology as a means to enhance the ...loading efficiency of nanoparticles. The loading efficiency of silver nanoparticles into the cotton fabric was examined by an atomic absorption spectrometer. The surface of the fibres was characterised by low-voltage scanning electron microscopy and attenuated total reflection-Fourier transform infrared spectrometry. The cotton fabrics loaded with Ag nanoparticles were examined by thermogravimetric analysis. In addition, the antibacterial activity of loaded samples was determined according to the AATCC test method 147-2004. Grafting of acrylic acid on cotton fibre leads to increase in the loading efficiency of silver nanoparticles and this sample showed the highest antibacterial activity.
Wide-angle X-ray scattering (WAXS) recordings were carried out on raw Dharwar cotton fibres available in Karnataka. Using this data and employing linked atom least squares (LALS) method, we report ...here the molecular and crystal structure of these cotton fibres. Employing structural data, we have computed elastic moduli tensor components of these fibres. From these investigations, it turns out that the intrinsic strains present in the fibre arise due to hydrogen bonds and not covalent bonds, which is a significant result.
Facile synthesis of ZnO hollow fibres Su, B T; Wang, K; Zuo, X W ...
Bulletin of materials science,
12/2007, Letnik:
30, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In this paper, cotton fibres were used as bio-template to successfully synthesize new ceramic materials, ZnO hollow fibres and in an effort to explore the synthesis condition, and simplify the ...synthesis procedure. In this synthesis, a direct thermal decomposition of zinc acetate dihydrate coated on the surface of cotton fibres was explored. The wall porosity of the ZnO hollow fibres was controlled by changing the concentration of zinc acetate aqueous solution.
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