ELECTROSPUN NANOFIBERS PREPARED BY TWO METHODS: IN SITU EMULSION POLYMERIZED PVA/NANOTIO2 AND MIXING OF FUNCTIONAL-PVA WITH NANOTIO2

Noora Ristolainen*, Pirjo Heikkilä**, Ali Harlin**, and Jukka Seppälä*
*Helsinki University of Technology, Laboratory of Polymer Technology, Espoo, Finland,
**Tampere University of Technology, Institute of Fibre Materials Science, Tampere, Finland

Poly(vinyl alcohol)/nano-sized titanium dioxide (PVA/nanoTiO2) water dispersions were electrospun in order to prepare networks of polymer composite nanofiber for coating applications. In particular, the effect of the functionalization of the polymer matrix, coating of the filler particles, and the preparation method of the polymer dispersions on the nanoparticle distribution along the resulting fibers were studied. The dispersions were prepared using two different techniques: batch in situ emulsion polymerization and mixing methods. Differently coated hydrophilic nanoTiO2 particles were used on one hand, and on the other, pure PVA and carboxyl- and silanol-functionalized PVAs were used. Dispersion properties were assessed by measuring viscosity and estimating the degree of homogeneity before electrospinning. The structure of the electrospun fibers was studied using scanning electron microscopy and elemental analysis. It was observed that the dispersion properties differed substantially depending on the types of polymer and filler particles used. Electrospinning succeeded in forming continuous fibers instead of separate droplets with all except one type of PVA/nanoTiO2 dispersions. It was confirmed that the resulting fibers and droplets contained nanoTiO2 particles. For the in situ polymerized dispersions the filler distribution in the resulting fibers was strongly influenced by the nanoparticle coating. In the mixing method, the resulting nanoparticle distribution was affected primarily by the polymer type used, and the role of the nanoparticle coating was not important.

Date Added: 2008-06-30
Date Added: 2008-06-30

THE INFLUENCE OF THE WEAVE AND THE METHOD OF STITCHING ON SELECTED MECHANICAL PROPERTIES OF WOVEN DOUBLE FABRICS

Elsayed A. ELNASHAR*, Polona D. DUBROVSKI**
*Faculty of Specific Education, Kafer Elsheikh, Tanta University, Egypt,
**Faculty of Mechanical Engineering, Maribor, Slovenia

This paper reports the influence of the weave and the method of stitching on the mechanical properties of double woven fabrics. Double fabrics have a more complex construction, which is altered not only by type of weave, yarn fineness, and thread density in comparison with single fabrics, but also by the method of stitching. The main goal of our research was to find out if the type of weave and method of stitching have a statistically important effect on selected mechanical properties of woven double fabrics, such as breaking strength, breaking elongation, tearing strength, wrinkle recovery and fabric stiffness, in order to extend the knowledge of double fabric construction. The testing samples were made from 100% cotton fabrics.

Date Added: 2008-06-30
Date Added: 2008-06-30

EXPERIMENTAL STUDY OF CAPILLARY RISE IN FABRICS USING AN ELECTRICAL RESISTANCE TECHNIQUE

Mohamed HAMDAOUI*,**, Faten FAYALA*,**, Patrick PERRÉ*** and Sassi BEN NASRALLAH*
*Laboratoire d'Etudes des Systemes Thermiques et Energétiques, Ecole Nationale d'Ingénieurs de Monastir, Tunisia
**Département de Génie Textile, Ecole Nationale d'Ingénieurs de Monastir, Tunisia
***Laboratoire d'Etudes et Recherche sur le Matériau Bois L.E.R.Ma.B., ENGREF, Nancy CEDEX, France

An electrical method has been used to study capillary rise in fabrics. This method is based on the measure of the electrical resistance and leads to the determination of time-space water content evolution. The obtained results allowed us to deduce the capillary pressure curve of the fabrics and the flow velocity.

Date Added: 2008-06-30
Date Added: 2008-06-30

EXTRACTION OF NATURAL DYES FROM AFRICAN MARIGOLD FLOWER (TAGETES EREECTA L) FOR TEXTILE COLORATION

D. Jothi
Textile Engineering Department, Bahir Dar University, Bahir Dar, Ethiopia

African marigold [Tagetes erecta L.], a major source of carotenoids and Lutin, is grown as a cut flower and a garden flower, in addition to being grown for its medicinal values. Marigold flowers [Tagetes], which are yellow to orange red in colour, are a rich source of lutein, a carotenoid pigment. Nowadays, Lutein is becoming an increasingly popular active ingredient used in the Food Industry and Textile coloration. This pigment has acquired greater significance because of its excellent colour value. Although marigold flower extract has been used in veterinary feeds, the potential use of marigold as a natural textile colorant has not been exploited to its full extent. This is due to the lack of information on its safety, stability, and compatibility in textile coloration. In this study, an experiment was conducted to study the use of an extract isolated from marigold as a natural dye. The dye potential of the extract was evaluated by dyeing, using the flower, in 100 % cotton and silk fabrics under normal dyeing conditions. Studies of the dyeability, wash fastness, light fastness, and colour hue were undertaken. The, L,a and 'b' of materials dyed using the extract were studied with the use of Computer Colour Matching software. The surface colour was not affected by washing, and the quality of the flower was maintained even washing at 60o C for 30 minutes. Studies have indicated that the change of some of the colors have been noticed after washing with soap. Most of the metal salts exhibited the highest K/S values, due to their ability to form coordination complexes with the dye molecules. These findings reveal that the extract of Marigold flower can be used for coloration of !00 % cotton, silk, and wool fabrics. This article deals with the chemistry, processing, and stability of the pigment and its applications in textile coloration.

Date Added: 2008-06-30
Date Added: 2008-06-30

EFFECT OF WATER HARDNESS ON ACID DYEING WITH SILK

KAN Chi-wai
Institute of Textiles and Clothing,
The Hong Kong Polytechnic University,
Hung Hom, Kowloon, Hong Kong, China

In this paper, the effect of water hardness, expressed in CaCO3 equivalent, on the dyeing of silk with acid dye under acid, alkaline and isoelectric point dyeing conditions was studied by the zeta potential method. Under acid conditions and in the presence of the calcium ion, the positive zeta potential of silk was found to decrease with a reduction in the dye adsorption. Such a phenomenon might be due to the presence of cation, which increases the dyeing potential barrier at the interface between the fibre and dye solution. This would result in a higher resistance of dye anions passing through the interface. Under alkaline conditions, the zeta potential on silk was negative and resulted in a strong potential barrier for the dye anions. The presence of the calcium ion would result in a decrease in the absolute value of zeta potential of silk fibre, with an overall increase in dye absorption. Under the isoelectric point, the zeta potential of silk fibre was found to be near zero and dye adsorption was not influenced by the cations. These results demonstrate that the calcium ion could produce a strong electrolytic effect on dyeing, even under very low concentrations.

Date Added: 2008-06-30
Date Added: 2008-06-30

PATENT STATISTICS ON THE WORLD TEXTILE INDUSTRY AND A LOOK AT GERMANY'S POSITION

Jan Hausding, Chokri Cherif
Institute of Textile and Clothing Technology
Technische Universität Dresden, Dresden, Germany

Some studies suggest that the number of patent applications can be used as an indicator to quantify the potential for innovation of industry sectors such as the textile industry. This paper shows the distribution of worldwide economic power and patent applications between 1978 and 2004 in the textile and textile machinery industry based on the example of for Germany. The number of patent applications from the textile sector is compared to that of other industries. Subsequently, the patent statistics are broken down into individual enterprises with outstanding numbers of applications, as well as to individual countries and branches within the textile industry.

Date Added: 2008-06-30
Date Added: 2008-06-30
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