**4.1 Subjective evaluation of fabric handle**

Subjective assessment treats fabric hand as a psychological reaction obtained from the sense of touch (Bakar, 2004). Traditionally, in the textile and clothing industries, the assessment of the fabric handle is carried out subjectively by individual judges. The judgements strongly rely on personnel criteria (Yick et al., 1995).

Figure 5 shows the change in thickness with pressure for a soft fabric together with the recovery in thickness as the pressure is removed. The steep initial slope of the curve makes it very difficult to measure thickness with any accuracy as a small change in pressure in this region causes a large change in measured thickness. Thickness at zero pressure always has to be obtained by extrapolation of the curve, as a positive pressure is needed to bring any

It is evident from studies on the subjective evaluation of fabric handle that warm-cool feeling of a fabric very often makes an important contribution to the perception of its over-all handle and quality in the context of a given end use (Bishop, 1996). Alambeta instrument developed by Hes can be used for measuring the warm-cool feeling (Bishop, 1996; Özçelik et al., 2008; Mazzuchetti et al., 2008; Hes, 2004). This feeling, which is generated when fabric initially contacts the skin, is related to the heat flow between the skin and the contacted object. Rough fabric surface reduces the area of contact appreciably, and a smoother surface increases the area of contact and the heat flow, thereby creates a cooler feeling. The correlation between transient heat flux and the warm/cool feeling was investigated by several researchers (Barker, 2002; as cited in Rees, 1941; as cited in Hollies et al., 1953; as cited in Kawabata et al. ,1985). It has been reported that transient heat flux significantly affects clothing comfort in next-to-skin

Prickle is a rather negative attribute associated particularly with fabrics containing a proportion of coarse animal fibres, having diameters of about 30 µm or more. When evaluating the handle and quality of wool containing fabrics, there has been obtained good correlation and therefore prickle characteristics of the fabrics should also be taken into consideration in objective handle measurements (Bishop, 1996). Although the luster and fuzzes of the fabric surface are not generally included in objective handle measurements, since the appearance of fabrics make an important contribution to consumers` garment preferences, the measurement of these properties should also be of interest in handle evaluation. The fabric noise and odour are not redundant in the subjective evaluation of

Fabric handle according to fabric sound has been investigated in recent days. Fabric sound in the forms of sound spectra through Fast Fourier Transform analysis was analyzed (Mitsuo, 2006; as cited in Yi & Cho, 2000). Level pressure of total sound, level range and frequency differences of fabric sound were compared to mechanical parameters measured by KES system (Mitsuo, 2006; as cited Cho et al., 2001, 2005). The physiological responses evoked by friction sounds of warp knitted fabrics to that of electroencephalog, the ratio of

Subjective assessment treats fabric hand as a psychological reaction obtained from the sense of touch (Bakar, 2004). Traditionally, in the textile and clothing industries, the assessment of the fabric handle is carried out subjectively by individual judges. The judgements strongly

textiles but these properties can be useful to evaluate fabric handle (Mitsuo, 2006).

measuring instrument into contact with the fabric surface (Saville, 1999).

**3.5 Other fabric properties related to sensorial comfort** 

fabrics (Barker, 2002; as cited in Kawabata et al., 1985).

high to low frequency were also studied (Mitsuo, 2006).

**4. Sensorial comfort of fabrics** 

**4.1 Subjective evaluation of fabric handle** 

rely on personnel criteria (Yick et al., 1995).

When a person runs their finger across the surface of a fabric, a complex multi-sensory, emotional and cognitive experience takes place. A memory is stirred, an emotion, feeling and association is evoked and a decision is made, an impression becomes embossed in the mind. Decisions and motivations are based on anticipated reality of preference, personality, emotion and moods, for audience or non-audience participation (Moody et al., 2001).

The subjective hand is the result of touch sensation and therefore is dependent on the mechanisms of human tactile sensations. The somatic senses are those nervous system mechanisms by which sensory information is collected from within body. The somatic senses are classified to the three groups:


It is then clear that subjective hand sensing is the combination of various receptors responsible for feeling of texture, pressure, stretching, thermal feedback, dynamic deformation and vibration and from the sum of their complex responses humans can perceive and discriminate between the textiles (Militky& Bajzík, 1997).

In the subjective assessment process of textiles, fabric hand is understood as a result of psychological reaction through the sense of touch. There are variations in how individuals actually feel textiles because people do not have the same sensory perception of identical occurrences. Affecting aspects can be grouped in sociological factors and the physiological factors.

The other main factors affecting the subjective handle evaluation can be defined as; the judges, the criteria of judgement, assessment conditions, assessment technique, the method of ranking and scaling the assessment, analysis of the results (Mahar et al., 1990; as cited in Brand, 1964; Bishop, 1996). Gender, age, education and cultural backgrounds are potential influencing factors. Female individuals in general respond more delicately and sensitively than male individuals and therefore have a finer assessment of a specific parameter (Mäkinen et al., 2005; as cited in Kweon et al., 2004; as cited in Dillon et al., 2000).

Since the services of expert judges are not widely available for research activities, generally students, laboratory assistants and other consumer groups work as panelists. Such panels should be capable of making consistent judgements of textile attributes and due to the high variability of these panelists compared to the expert judges, larger panel sizes should be preferred, at around 25-30 persons (Bishop, 1996).

In order to ensure the reliability of subjective assessments, it is critical to choose the right expressions for the description of a fabric handle parameter (Mäkinen et al., 2005). There are different sensory attributes identified by numerous authors. These are grouped as given in Table 1 (Hu, 2008). The words "thickness," "thinness," "softness," "stiffness," "slippery," "roughness," "tightness," "fullness" and "pliable" are mostly used expressions to describe the feel of a fabric (Sülar & Okur, 2007).

Generally, in order to evaluate the handle of the fabric, fingers are slid on the surface of the fabric, compressed between the thumb and sign finger. The fingers containing more than

Sensorial Comfort of Textile Materials 247

The assessment conditions of subjective handle evaluation are critically important. Different skin hydrations of individuals affect notably the feel of a textile. A higher moisture level on

The evaluation is carried out in three different conditions: sight only, touch only and sight and touch together. During the assessment, in order to prevent the effect of colour and appearance on the assessments, wooden boxes with holes on the facing sides, through which the hands can easily go, can be used. Fabric samples are placed in these boxes prior to assessments. This helps the jury to assess the fabric without seeing it (Sülar &Okur, 2008b). The first attempts of ranking and scaling the assessment methods in hand evaluation of textiles in an organized and quantitative manner were published as early as 1926 and have continued up to the present time and two basic procedures of subjective hand evaluation is

a. Direct method - is based on principle of sorting of individual textiles to defined subjective grade in ordinal scale (e.g., 0 - very poor, 1 - sufficient, 5 - very good, 6 -

b. Comparative method - is based on sorting of textiles according to subjective criterion of evaluation (e.g., ordering from textiles with the most pleasant hand to textiles with the worst hand) (Bakar, 2004). If the number of samples is high, the second approach can be

It is preferable to use a paired comparison technique during assessment, the so-called bipolar pairs of sensory attributes, such as "thin/thick" or "soft/harsh" (Mahar et al., 1990; as cited in Brand, 1964). For the same reason, fabric hand attributes are measured on specific scales thus avoiding the intrinsic weakness of descriptive terminology. In case of using bipolar descriptors in the assessment of the handle, control fabrics are better to be used for the training of the panel members. Control fabrics are chosen according to the related objective properties. The test results for objective properties that are related to sensory attributes were sorted in ascending order for each parameter. The fabrics with minimum, maximum and medium values are determined and used for the initial tests for the selection

It is crucially important to convert the subjective assessment results to the numerical values for finding a relationship between objective measurements to analyze statistical evaluation.

1 … 5 … 10 thinnest … medium … thickest 1 … 5 … 10 softest … medium … stiffest 1 … 5 … 10 smoothest … medium … rougest 1 … 5 … 10 proper … medium … most proper

the skin makes it more sensitive to the sense of touch (Mäkinen et al., 2005).

proposed as follows: (Bakar, 2004; as cited in Howorth,1964):

considered rather time consuming (Sülar & Okur, 2007).

Therefore, using these types of ranking scale is preferable (Table 3).

Table 3. Handle components and the rating scale (Sülar & Okur, 2008a)

of the control fabrics (Sülar & Okur, 2007).

excellent).

250 sensors per cm2 are the crucial important organs determining the fabric quality (Bensaid et al., 2006). Tightening of the fabric between fingers gives idea about thickness, bulkiness, compressibility, thermal absorptivity and surface properties of the fabrics, whereas slipping of the fingers on the surface of the fabrics with a pressure renders about structure and elongation of the fabrics (Aliouche & Viallier, 2000).


Table 1. Sensory attributes of fabrics

There are generally four handle methods for the evaluation of fabric handle, as shown in Figure 6. The multiple finger pinch and the touch-stroke are the most relevant ones.

However, using just the index finger has also proved acceptable. Evaluated properties of the fabrics by these handle techniques are given in Table 2 (Moody et al., 2001; as cited in Dillon & Moody, 2000).

Fig. 6. Handle techniques (1. Touch stroke, 2.Rotating cupped, 3.Multiple finger, 4.Two handed rotation) (Moody et al., 2001)


Table 2. Properties evaluated by different handle techniques (Moody et al., 2001)

250 sensors per cm2 are the crucial important organs determining the fabric quality (Bensaid et al., 2006). Tightening of the fabric between fingers gives idea about thickness, bulkiness, compressibility, thermal absorptivity and surface properties of the fabrics, whereas slipping of the fingers on the surface of the fabrics with a pressure renders about structure and

Stiffness/crispness/pliability/flexibility/limpness Anti-drape/spread/fullness Softness/harshness/hardness Tensile deformation/

There are generally four handle methods for the evaluation of fabric handle, as shown in

However, using just the index finger has also proved acceptable. Evaluated properties of the fabrics by these handle techniques are given in Table 2 (Moody et al., 2001; as cited in Dillon

Figure 6. The multiple finger pinch and the touch-stroke are the most relevant ones.

Fig. 6. Handle techniques (1. Touch stroke, 2.Rotating cupped, 3.Multiple finger, 4.Two

**Handle Technique Properties Evaluated**  1 Touch-stroke Surface quality (texture), temperature <sup>2</sup>Rotating cupped action Stiffness, weight, temperature, comfort,

overall texture, creasing

stretch (force-feedback)

Texture, stiffness, temperature, fabric structure, both sides of a fabric, friction,

Thickness/bulkiness/sheerness/thinness Compressibility Weight/heaviness/lightness Snugness/loosenes Warmth/coolness/coldness (thermal characteristics) Clinginess/flowing Dampness/dryness/wetness/clamminess Quietness/noisiness

bending/surface friction/sheer

Smoothness/fineness/silkiness

elongation of the fabrics (Aliouche & Viallier, 2000).

Prickliness/scratchiness/roughness/coarseness/itch

iness/tickliness/stickiness/

Table 1. Sensory attributes of fabrics

handed rotation) (Moody et al., 2001)

and 1 or 2 fingers)

Multiple finger pinch: Rotating between the fingers action with one hand (thumb

4 Two handed rotation action Stretch, sheerness

Table 2. Properties evaluated by different handle techniques (Moody et al., 2001)

Looseness/tightness

& Moody, 2000).

3

The assessment conditions of subjective handle evaluation are critically important. Different skin hydrations of individuals affect notably the feel of a textile. A higher moisture level on the skin makes it more sensitive to the sense of touch (Mäkinen et al., 2005).

The evaluation is carried out in three different conditions: sight only, touch only and sight and touch together. During the assessment, in order to prevent the effect of colour and appearance on the assessments, wooden boxes with holes on the facing sides, through which the hands can easily go, can be used. Fabric samples are placed in these boxes prior to assessments. This helps the jury to assess the fabric without seeing it (Sülar &Okur, 2008b).

The first attempts of ranking and scaling the assessment methods in hand evaluation of textiles in an organized and quantitative manner were published as early as 1926 and have continued up to the present time and two basic procedures of subjective hand evaluation is proposed as follows: (Bakar, 2004; as cited in Howorth,1964):


It is preferable to use a paired comparison technique during assessment, the so-called bipolar pairs of sensory attributes, such as "thin/thick" or "soft/harsh" (Mahar et al., 1990; as cited in Brand, 1964). For the same reason, fabric hand attributes are measured on specific scales thus avoiding the intrinsic weakness of descriptive terminology. In case of using bipolar descriptors in the assessment of the handle, control fabrics are better to be used for the training of the panel members. Control fabrics are chosen according to the related objective properties. The test results for objective properties that are related to sensory attributes were sorted in ascending order for each parameter. The fabrics with minimum, maximum and medium values are determined and used for the initial tests for the selection of the control fabrics (Sülar & Okur, 2007).

It is crucially important to convert the subjective assessment results to the numerical values for finding a relationship between objective measurements to analyze statistical evaluation. Therefore, using these types of ranking scale is preferable (Table 3).


Table 3. Handle components and the rating scale (Sülar & Okur, 2008a)

Sensorial Comfort of Textile Materials 249

organized by Professor Kawabata. In this fabric objective measurement method, scientific principles are applied to the instrumental measurement and fabric low stress mechanical and surface properties such as fabric extension, shear, bending, compression, surface friction and roughness are measured. The fabric handle is calculated from measurements of these properties. Empirical equations for calculating primary hand values and total hand values were put forward by Kawabata and Niwa (Mäkinen et al., 2005; as cited in Kawabata, 1980;

The process of the subjective evaluation according to Kawabata can be given as follows

"primary hand"

The first part of Kawabata`s work was to find the important aspects of handle and the contribution of each to the overall rating of the fabric. For each category such as stiffness, smoothness, etc. were identified and the title of primary hand values were give. The original Japanese terms of these primary hand definitions together with English meanings are given in Table 4. The primary hand values are combined to give an overall rating for the fabric categories such as man's summer suiting, man's winter suiting, lady's thin dress, and man's dress short and knitted fabrics for undershirts. The conversion of the primary hand values is done by using a translation equation for a particular fabric category determined empirically. This total hand value is rated on a five point scale, where five is the best rating (Kawabata,

The second stage of Kawabata`s work was to produce a set of instruments with which to measure the appropriate fabric properties and then to correlate these measurements with the subjective assessment of handle. The aim was that the system would then enable any

The Kawabata Evaluation System for Fabric (KES-F) which has been widely used since the 1970's consists of four specialized instruments: FB1 for tensile and shearing, FB2 for bending, FB3 for compression and FB4 for surface friction and variation. A total of 16 parameters are measured at low levels of force (Table 5). The measurements are intended to

operator to measure reproducibility the total hand value of a fabric (Saville, 1999).

simulate the fabric deformations found in use (Hu, 2008; Chen et al., 2001).

Fig. 7. Measuring principles of the KES system

 Summarized expressions → about fabric characters by Overall

→judgement of fabric quality

as cited in Shishoo, 2000).

Detection of fabric basic mechanical properties such as bending, stiffness, etc.

Physiological sensing data processing in man's brain

(Bona, 1994):

Touch of fabric by hand

1980).

This subjective hand evaluation system requires years of experience and can obviously be influenced by the personal preferences of the assessor as mentioned before. A fabric may be felt light, soft, mellow, smooth, crisp, heavy, harsh, rough, furry, fuzzy or downy soft. So there is a need to replace the subjective assessment of fabrics by experts with an objective machine-based system which will give consistent and reproducible results (Hu, 2008).
