Textile Chemistry

Assignment 03

Submitted by: Nalaka Sampath Submitted to: Sir, Ariyasiri Nandasena

Comment on the statement “Evaluation of

softness on fabric is more subjective”

and

Give various types of softness and mention

their properties.

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Subjective evaluation of softness on fabric

When we talk about the textile industry, it’s important to know what the qualities

of textile materials are or garment product should be achieved before they go to the

market. There would be many or few unique qualities to the fabrics, which the

customers are looking for their desires. In some times those products are not be able to

fulfill the necessity according the costumer’s requirements. In this case, while the

producing of garment and other textile materials, its required qualities and other

properties are achieved by some kind of treatments called, textile finishing.

Comfort of a fabric is one of the most important

thing, which is achieved by during the textile finishing. Actually this finishing process for

develop the quality and give a high value to the textile materials. While upgrading the

quality of a fabric, its added softening process also..

Softness are for give a soft feel to hand of fabric. Softness on

fabric can be measured by some technical process. But measuring this softness on

fabric is not as easy as giving soft finish on it. (There are some mathematical

calculations and equipment to measure softness). In this case the most common

method is used for measure softness of fabric, is “subjective evaluation”. Even though it

has some parameters to measure softness by human sense, it would be varied

according to the evaluator’s desires. That’s why this topic has taken as “Evaluation of

softness on fabric is most subjective.”

Before we talk about softness on fabric, it’s important to know what the things

which resultants to fabric softness are. For an example, if take “X” and “Y” two

evaluators and “A” and “B” two fabrics, X can feel more softening effect/ hand property

and fabric surface’s smoothness on “A” fabric. This can be depended on his likeness

and his privet desires. But those things in Y aren’t as same as in X. These two people

have two difference likenesses. That’s why Y choses B fabric which can give him more

softness than from A fabric.

So here we can see, it’s important to know which the things resultant to fabric

softness are and important to understand what are the ways can be used to give

softness and identify them.

The ways of textile material have built up: The main two methods of making fabric -

knitting and weaving- directly resultant to softness on fabric. Optimizing (increasing and

decreasing some qualities of structure in knitting and weaving to get more softness on

fabric) fabric to the high value of comfort, is the best way to have soft finish on a fabric.

As we discussed earlier, these method (knitting or weaving and the technique have

used) can be caused to a person to feel difference softness on fabrics. This is a one

proof to conform the evaluation of softness on fabric more subjective.

The mechanical finish has done on fabric: Softness not only can be given to a

fabric by the way of it has made out. It can be developed after the producing also. The

finish which is given mechanically –calendaring the fabric, brushing or peaching on

fabric- can be affected to someone to feel more comfort than from another type of fabric

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which is subjected to difference mechanical processes of softening. As we discussed

before the way of feels softness on fabric to person to person, as the same type of

softness on fabric can be varied according to the way of softening effect have gave out

and machineries have used. So this softening effect also supports to total effect of

softness on fabric and it also vary softening feel.

Dyes and chemicals have used: colour of fabric also can be caused to someone to feel it’s

giving more comfort to him. Actually this is a psychological thing, which feels some

colours giving more softness than others. When a fabric is made out from those colors,

it’s psychologically tempting to feel softness on fabric. This thing can be varied to

person to person to feel softness according the colour of fabric has made out. And the

chemicals also effects in same way. Some softening chemical like silicon softness,

anionic\cationic softness and others can be gave out varying softening feel to the

evaluators based on the chemicals it has used.

Above mentioned softening effects can be sensed to evaluator from difference

values and it’s difficult to give an actual percentage or a value to the softness on fabric

by a subjective evaluation. The evaluators panel used to evaluate the fabric hand, they

take some average value according to their parameters. But this is also not the actual

value of softness, but base on evaluators evaluation.

Finally if we take these above mentioned things together, simply we can

understand what the subjective evaluation is. As this evaluating method is depended on

hand on fabric, it varies evaluator to evaluator according to his likeness and mostly on

his senses. That’s why the evaluation on fabric is more subjective.

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Cationic softness: These are recommended for all types of fibre, and can be also applied with

exhaustion process in acid environment (pH 4-5). And they form bonds with the cationic group on the surface of the fibre generally with negative electric potential.

The simplest cationic are the primary, secondary and tertiary mono‐amines and their salts, formed by neutralization of the amines with acetic acid. These are quite water soluble, give good softening properties and are easy to make. As cationic softeners have positive charge they are affected to cotton or synthetic fabric. Properties of cationic softener

Compatible with most resin finishes. Tendency to change the shade. Affects the fastness of certain dyestuffs. Causes discoloration on white fabrics. Very soft, silky hand to fabric.

Anionic softness:

Anionic softening agent can be used as a processing agent for rayon filament

yarn and staple fiber to impart a soft handle. These are available in the form of off‐white thick paste, creamish viscous paste. Being anionic in character, they are compatible with direct dyes, optical whitening agents, starches, resins, blueing agents, etc and they are stable to hard water, dilute alkalies and dilute acids. They may be applied on cotton, viscose rayon, acetate rayon, silk and nylon yarns to produce soft and supple finishes. Properties of anionic softness

Strong antistatic effects. compatible with dyes and bleach baths Poor washing fastness. Fabric gets a lofty handle.

Amphoteric softness: Amphoteric softness can be made out of cationic, anionic or non-ionic. Its depending upon the pH of the aqueous solution. They have fewer ecological problems than similar cationic products. Betaine and the amine oxide type are the used compound for these. Amphoteric surfactants offer an excellent degree of lubrication, and wetting action and provide a protective colloid for silk and wool. These softness are comparatively expensive and some of them are not heat stable and hence cannot use at elevated temperature.

Properties of Amphoteric softener

Low permanence to washing.

High antistatic effect.

Excellent degree of lubrication.

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Silicone softeners: These are insoluble in water, and therefore must be applied on fabrics after dissolution in organic solvents, or in the form of disperse products. They provide very high softeners, special unique hand. They feature quite good fastness to washing. There are two types of silicon softness. • Micro emulsion

• Macro emulsion

Micro emulsion It’s particle size is less than 40 nm. Because of that, it is clear in

appearance and looks like water. As this softness containing smallest molecules, they can penetrate into fires inside also. So this softness can give inner softness to fabrics.

Macro emulsion

Macro emulsion has bigger molecular than micro emulsion and its

particle size is in the range between 150‐250 nm. Because of that macro emulsion is milky in appearance. These emulsions cannot be penetrated into fibres inside, as its molecular size is large. So it gives surface softness as it covers the fiber surface.

Properties of silicon softness Durable wash fast finishing effects. Abrasion resistance. Crease recovery. High sew ability. Very soft, smooth. Supple handle.

Polyethylene softness: Polyethylene is a non‐ionic softener which is formulated to achieve bulky, bouncy

and elastomeric finish. It can be used for cotton, polyester/cotton fabrics. It has a very

good hand feeling and anti‐static properties. Because of its low‐yellowing specific character, it is very suitable for garment processing of blue and white jeans. These softness are can be applied at neutral pH. Properties of polyethylene softness

No influence on dyeing fastness. Does not irritate human skin. Very good handle and soft feeling. Provides bulky and heavy feel. Does not cause fabric yellowing.

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