Saturday, November 29, 2008

Textiles toys

As all of us knows textile has already cross its barriers from traditional apparels to various other fields such as geotech, agritech, industrial application, autotech and sporttech. A lot of books and papers are available on such an application. But apart from these advanced high tech applications textile from ancient times have been used for non apparel applications. One of such application is use of textiles in preparing toys.

Various toys made up from textile materials have been made from the years ago. Today the market for such textile toys is tremendous. In the year 2005-06, the total toy industry was $2.2 billion globally toy industry growing at five per cent. Moreover China is a major player and forms about 70 per cent of the total global toy market.

Typical textile toys are various animal shaped toys, designed pillows, etc are made up of stuff polyfoam beads with outer cloth material of spandex, polyester, etc. These textile toys are easily available in the retail shops and on internet shopping sites with a good variety.

Tuesday, November 25, 2008

softeners

A Softener is a chemical that alters the fabric hand making it more pleasing to the touch. The more pleasing feel is a combination of a smooth sensation, characteristic of silk, and of the material being less stiff. The softened fabric is fluffier and has better drape. Drape is the ability of a fabric to follow the contours of an object. In addition to aesthetics (drape and silkiness), softeners improve abrasion resistance, increase tearing strength, reduce sewing thread breakage and reduce needle cutting when the garment is sewn.
The application of softening substances turns a hard and brittle fabric into a soft, pleasant textile with which the buyer can expect a high degree of wearing comfort and wearing properties.

Chemistry of Softeners
The continual proliferation of textile softeners can be attributed to their molecular diversity, performance versatility and the multiplicity of fibres, blends and application processes. Based on polarity or ionic nature, softeners are categorised into four basic types:
1) Nonionic softeners.
Mono – di - glycerides
Glycol esters
Stearamides
2) Cationic softeners
Fatty amidoamine acid salts
Quaternary fatty amidoamines
Quaternary tertiary amines
Quaternary imidazolines.
Gemini Surfactants (Bis-Quaternary Ammonium Salt)
3) Anionic softeners
Sulfated triglycerides
Sulfated fatty alcohols
Anionically emulsied glycerides
4) Amphoteric softeners
Imidazoline carboxylate salts
Imidazoline sulfonate salts
5) Special softeners
Polyethylene emulsions
Silicone emulsions
Author: Mukesh R.

Tuesday, November 11, 2008

phase change materials

Phase change material PCM are thermal storage materials and are use to regulate temperature fluctuations. PCM means incarporating microcapsules into textie structure to store energy and it happens when they change from solid to liquid and dessipiate it when they get changed from liquid to solid.
PCM material : the constituting microcapsules of paraffin, waxes with various phase change temerature depending on carbon number enclosed are of diameter 1-30micro meter.

Author : Miss Supriya Mazge, (SGGSIE&T, Nanded)

Monday, November 3, 2008

Methylene Blue Absorption

Bleaching is the most important process in textile wet processing which gives white goods. Methylene blue absorption is one of the several methods to estimate the bleaching efficiency.

The absorption of methylene blue by cellulose derivative is generally due to the -COOH groups present in oxycellulose formed by alkaline oxidation (due to bleaching agent) but it may also be due to mineral acids which have been dried into cellulose and are not easily washed out.
The method depends upon treating the sample with a methylene blue solution of known strength and buffered to a known pH and determining the concentration of the methylene blue in the solution either by titration with naphthol yellow or by colorimetric method.

Procedure by titration method

A sample of 2.5 gm weight is placed in test tube or small flask. 15cc of methylene blue is added from burette. The titration is carried out at room temperature. 10cc of solution is withdrawn and titrated with naphthol yellow S. The ethylene blue absorbed by sample is calculated in milimoles per 100gm of dry sample.

Colorants

Traditionally, colorants have been classified into dyes and pigments which are being used in the process of coloring materials. Coloration is a physical process whereby we apply dyes to textiles or incorporate pigments into paints, inks and plastics by dispersion.

But today, we can no longer limit colorants to conventional dyes and pigments.

Color means an effect perceived by an observer and determined by the interaction of the three components of light source, object and observer.

Chromatic colorants have selective absorption and scattering of light which vary with the wavelength. So they can selectively modify the spectral power distribution of light falling on them. Achromatic colorants such as black and grey are spectrally non-selective absorbers while white pigments are spectrally non-selective scatterers.

In short, for our understanding, we can say, colorant is a substance that is used to impart colour to objects. But at the same time, the general classification into dyes as soluble and pigments as insoluble, does not hold any ground in recent years.


Why?

If the colorant has an affinity for the substrate (textile, paper etc.) and will become a part of the colored material without the need of an intermediate binder, we consider such a colorant to be a dye. Dyes, whether, direct, vat, disperse, solvent-soluble or any other type, are dyes because a binder is not required to hold them on the material being colored.

On the other hand, the pigment does require a binder so that it is fixed to the substrate as it does not have affinity to the substrate. A pigment applied to a surface without a binder will not adhere to the surface.

Author: Sambhaji Chopdekar, Institute of Chemical Technology, Mumbai.
Source: Billmeyer and Saltzman’s PRINCIPLES OF COLOR TECHNOLOGY (Third Edition) by Roy S.Berns, A John Wiley and Sons Co., USA (2000)