Assessment of Fabric Hand (II)Assessment of Fabric Hand (II)Data Analysis on fabric hand valueData Analysis on fabric hand value

Dr. Jimmy LamDr. Jimmy Lam

Institute of Textiles & ClothingInstitute of Textiles & Clothing

Learning ObjectivesLearning Objectives

Subjective Hand Assessments on wool/wool Subjective Hand Assessments on wool/wool blend fabrics and cotton/cotton blend fabrics.blend fabrics and cotton/cotton blend fabrics.

The relationships between primary hand values The relationships between primary hand values and total hand value on hand assessments.and total hand value on hand assessments.

Subjective Assessment of HandSubjective Assessment of HandWool/Wool Blend fabricsWool/Wool Blend fabrics

Based on the criteria of hand assessment as discussed Based on the criteria of hand assessment as discussed in previous section, a total of ten wool/wool blend in previous section, a total of ten wool/wool blend fabrics are used to conduct the subjective hand fabrics are used to conduct the subjective hand assessments in Hong Kong.assessments in Hong Kong.

The fabric weight ranges from 150 g/mThe fabric weight ranges from 150 g/m2 to 242 g/m to 242 g/m2, , with material of pure wool and wool/polyester blend with material of pure wool and wool/polyester blend fabrics.fabrics.

The surveyed fabric samples are shown in Table 2.9 The surveyed fabric samples are shown in Table 2.9 and the average primary hand value and total hand and the average primary hand value and total hand value (THV) of these ten fabrics assessed by the panel value (THV) of these ten fabrics assessed by the panel of twenty-eight judges are shown in Table 2.10of twenty-eight judges are shown in Table 2.10

Research Questions Research Questions Table 2.10 shows the survey results from twenty-eight judges on ten Table 2.10 shows the survey results from twenty-eight judges on ten

wool/wool blend samples on fabric hand assessment.wool/wool blend samples on fabric hand assessment. What can you tell from these Primary Hand Values and Total Hand What can you tell from these Primary Hand Values and Total Hand

Value ?Value ? Are there any relationship between Primary Hand Values and Total Are there any relationship between Primary Hand Values and Total

Hand Value?Hand Value? If there is, which one plays a significant role to explain the total hand If there is, which one plays a significant role to explain the total hand

value of these ten fabric samples?value of these ten fabric samples? Are there any variations between these twenty-eight judges on fabric Are there any variations between these twenty-eight judges on fabric

hand values assessment?hand values assessment? The results from these survey (expert judges) can it be simulated by The results from these survey (expert judges) can it be simulated by

a set of testing instruments? If so, objective measurement can be a set of testing instruments? If so, objective measurement can be done on fabric hand.done on fabric hand.

Correlation Matrix (1)Correlation Matrix (1)Primary Hand Values & Total Hand ValuePrimary Hand Values & Total Hand Value

To access the relationship between the fabric total hand To access the relationship between the fabric total hand value (THV) and the primary hand values of these ten value (THV) and the primary hand values of these ten wool and wool blend fabrics for men’s winter suitings, wool and wool blend fabrics for men’s winter suitings, a correlation analysis was carried out with the results a correlation analysis was carried out with the results shown in Table 2.11shown in Table 2.11

The results shown that THV is positively correlated The results shown that THV is positively correlated with fabric smoothness with R=0.84, but negatively with fabric smoothness with R=0.84, but negatively correlated with fabric stiffness with R=-0.82.correlated with fabric stiffness with R=-0.82.

This means that the primary hand value of smoothness This means that the primary hand value of smoothness of these ten wool/wool blend fabrics as assessed by the of these ten wool/wool blend fabrics as assessed by the judges make a significant positive contribution to the judges make a significant positive contribution to the fabric total hand value.fabric total hand value.

Correlation Matrix between THV and Primary Hand Values

Correlation Matrix (2)Correlation Matrix (2)

For the fabric primary hand value of stiffness, the For the fabric primary hand value of stiffness, the result means that the smaller is the stiffness, the higher result means that the smaller is the stiffness, the higher is the total hand value as assessed by the judges.is the total hand value as assessed by the judges.

The relationships of THV to fabric smoothness and The relationships of THV to fabric smoothness and stiffness is shown in Figure 2.1 and 2.2 respectively.stiffness is shown in Figure 2.1 and 2.2 respectively.

It should be noted that the primary hand value of It should be noted that the primary hand value of softness as assessed by the judges, does not play any softness as assessed by the judges, does not play any significant role in determining the fabric total hand significant role in determining the fabric total hand value, with correlation coefficient of R=-0.11.value, with correlation coefficient of R=-0.11.

SummarySummary In summary, the judges in favour a large fabric primary hand value of In summary, the judges in favour a large fabric primary hand value of

smoothness to contribute directly to the fabric total hand value for smoothness to contribute directly to the fabric total hand value for these ten wool/wool blend winter suiting fabrics.these ten wool/wool blend winter suiting fabrics.

For the primary hand value of fabric stiffness, the lower is its value, For the primary hand value of fabric stiffness, the lower is its value, the higher is the total hand value for these ten wool/wool blend the higher is the total hand value for these ten wool/wool blend fabrics.fabrics.

This is true as the quality of the high grade wool suitings is normally This is true as the quality of the high grade wool suitings is normally determined by fabric smoothness and fabric stiffness plays a negative determined by fabric smoothness and fabric stiffness plays a negative role in determining the fabric quality.role in determining the fabric quality.

However, it is interesting to note that the judges do not agree on the However, it is interesting to note that the judges do not agree on the contribution of the primary hand value of softness to the total hand contribution of the primary hand value of softness to the total hand value of these wool/wool blend fabrics when considered for use as value of these wool/wool blend fabrics when considered for use as men’s winter suiting materials.men’s winter suiting materials.

Subjective Assessment of Hand for Subjective Assessment of Hand for Cotton/cotton blend fabricsCotton/cotton blend fabrics

Hand assessment on Cotton denim Hand assessment on Cotton denim fabricfabric

Another set of ten cotton/cotton blend fabrics was selected to Another set of ten cotton/cotton blend fabrics was selected to conduct the subjective hand assessment.conduct the subjective hand assessment.

These ten medium to heavy weight cotton fabrics are mainly These ten medium to heavy weight cotton fabrics are mainly used for trousers or denim and the fabric weight ranges from used for trousers or denim and the fabric weight ranges from 199 g/m2 to 500 g/m2.199 g/m2 to 500 g/m2.

The fabric structure is twill and the fibre composition is pure The fabric structure is twill and the fibre composition is pure cotton with some of fabrics using Lycra as a weft yarn to cotton with some of fabrics using Lycra as a weft yarn to increase the fabric extensibility.increase the fabric extensibility.

The cotton fabric characteristics are shown in Table 2.15. The The cotton fabric characteristics are shown in Table 2.15. The average primary hand values and total hand values of these ten average primary hand values and total hand values of these ten fabrics are shown in Table 2.16.fabrics are shown in Table 2.16.

Research Questions for cotton Research Questions for cotton denim fabricsdenim fabrics

Similar to wool/wool bend fabrics, what conclusion can Similar to wool/wool bend fabrics, what conclusion can you draw from Table 2.16?you draw from Table 2.16?

Are there any relationships between primary hand Are there any relationships between primary hand values and total hand value for these ten medium to values and total hand value for these ten medium to heavy weight denim fabrics?heavy weight denim fabrics?

If so, which one plays a significant role to explain the If so, which one plays a significant role to explain the fabric total hand value?fabric total hand value?

What are the difference between the primary hand What are the difference between the primary hand values and total hand value obtained from these cotton values and total hand value obtained from these cotton fabric to wool fabrics?fabric to wool fabrics?

Correlation Matrix for cotton/cotton Correlation Matrix for cotton/cotton blend fabricsblend fabrics

Results of cotton fabricsResults of cotton fabrics Table 2.17 shows that the THV has a strong positive Table 2.17 shows that the THV has a strong positive

correlated with fabric smoothness with R=+0.96, but correlated with fabric smoothness with R=+0.96, but negatively correlated with fabric stiffness with R=-0.95.negatively correlated with fabric stiffness with R=-0.95.

This means that the twenty-eight judges agree on the fabric This means that the twenty-eight judges agree on the fabric smoothness as one of the key positive factors contributing to smoothness as one of the key positive factors contributing to the total hand value for these ten cotton fabrics for denim the total hand value for these ten cotton fabrics for denim trousers.trousers.

For the primary hand value of stiffness, the lower is its For the primary hand value of stiffness, the lower is its value, the higher is the total hand value.value, the higher is the total hand value.

This latter result shows that the judges do not favour fabric This latter result shows that the judges do not favour fabric stiffness from the viewpoint of fabric hand.stiffness from the viewpoint of fabric hand.

Results: Cotton Fabrics (1)Results: Cotton Fabrics (1)

The two results for the primary hand values of fabric smoothness The two results for the primary hand values of fabric smoothness and stiffness contribute to THV for cotton fabric are in the same and stiffness contribute to THV for cotton fabric are in the same sense as for wool/wool blend fabrics for men’s winter suitings.sense as for wool/wool blend fabrics for men’s winter suitings.

There is a weak positive correlation between THV and primary There is a weak positive correlation between THV and primary hand value of softness for these ten cotton/cotton blend fabrics, hand value of softness for these ten cotton/cotton blend fabrics, with correlation coefficient of R=+0.42.with correlation coefficient of R=+0.42.

These judges have difficulty in determining whether the fabric These judges have difficulty in determining whether the fabric softness contributes to the fabric total hand value.softness contributes to the fabric total hand value.

Although fabric softness shows a weak positive correlation with Although fabric softness shows a weak positive correlation with THV for these cotton fabrics, the judges are not sure if the effect THV for these cotton fabrics, the judges are not sure if the effect on softness will play a significant part in explaining the fabric on softness will play a significant part in explaining the fabric total hand value.total hand value.

Results: Cotton Fabrics (2)Results: Cotton Fabrics (2)

It is interesting to note that the judges maybe in slightly It is interesting to note that the judges maybe in slightly better agreement on fabric softness for these ten better agreement on fabric softness for these ten cotton/cotton blend fabrics (for denim trousers) than for cotton/cotton blend fabrics (for denim trousers) than for wool/wool blend winter suiting fabrics.wool/wool blend winter suiting fabrics.

The correlation coefficient between fabric softness and THV The correlation coefficient between fabric softness and THV for cotton/cotton blend fabrics is +0.42 and for wool/wool for cotton/cotton blend fabrics is +0.42 and for wool/wool blend fabrics is only -0.11.blend fabrics is only -0.11.

The judges appear to have more difficulty in determining the The judges appear to have more difficulty in determining the effect of fabric softness on THV for wool/wool blend fabrics effect of fabric softness on THV for wool/wool blend fabrics than for cotton fabrics.than for cotton fabrics.

DiscussionDiscussion

What conclusion you can draw from the hand What conclusion you can draw from the hand assessment between wool and cotton fabrics in this assessment between wool and cotton fabrics in this study?study?

What are the relationships between primary hand What are the relationships between primary hand values and total hand value on these survey?values and total hand value on these survey?

Is it possible to draw a generalization on fabric hand Is it possible to draw a generalization on fabric hand value on wool and cotton fabric?value on wool and cotton fabric?

Is it possible to simulate the knowledge of expert Is it possible to simulate the knowledge of expert judgements on a simple set of testing instruments ?judgements on a simple set of testing instruments ?