EFFECT OF FINISHES ON FABRIC DRAPE

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2 EFFECT OF FINISHES ON FABRIC DRAPE 8.1 lntroductlon 8.2 Materials 8.3 Methods 8.4 Results and Discussion Scoured material Mercerised material Bleached material Dyed material Effect of washing on fabric drape Comparison of Fabric Drape in Dry and wet state 8.3 Conclusions

3 EFFECT OF FINISHES ON FABRIC DRAPE 8.1 INTRODUCTION Newly constructed fabrics as they come from mill are called 'gray goods', which consists of unfinished goods (fabrics). These unfinished goods pass through various finishing processes to make it suitable for its intended end use namely clothing. Finishing may change the appearance of the fabric, its hand (feel), its senriceability, and its durability. For the present study cotton dress material was selected as cotton is described as 'King of Fibres'. For hot country like India, cotton fabrics are preferable for clothing purpose. Cotton does not intrinsically have the body and suppleness required for good drapeablity. Finishing treatment on the cotton can enhance the property of fabric drape. 8.2 MATERIALS used. For applying finishing treatment a loom state cotton dress material was

4 8.3 METHODS The fabric drape measurement was taken by the use of Cusick drapemeter. After every step of finishing process on cotton fabric, the drape coefficient was determined for analyses. 8.4 RESULT AND DISCUSSION Effect of Flnlshlng Process on Fabric Drape Before any treatment was applied to the loom state fabric the initial drape coefficient was determined after every finish, and the drape was determined and the result was recorded. Gray goods had very high drape coefficient, which implies poor drapeabliity. This is due to the fact that unfinished product contains many impurities like dirt, wax, etc., which entangle between the fibres and obstructs the bending property of the fabric which in turn has poor drape Scoured Materials The process of scouring partially removes higher order dirt particles, like grease, cotton lint, and etc., thereby slightly improving the drapeability of fabric. This is clearly evident in the Table 8.1 and in the Fig 8.1. The scouring process removes the wax which in turn improves the bending quality of the fabric and on other hand its stiffness is slightly reduced.

5 Table 8.1 Drape Coefficient and Drape distance ratio for Finishing Treatment Applied on Loom State Cotton fabric - - S. No Finishing Treatment Drape Coefficient ("/.) Drape distance ratio 1 Gray fabric Scoured Mercerised Bleached

6 Figure 8.1 Effect of Finishing Treatment on the fabric Drape

7 Mwcdsexl Material The process of mercerization improves the physical structure of cotton. The caustic soda treatment causes the flat twisted, ribbon like, cotton fibre to swell into a round shape and to contract in length. This treatment improves the creasing property of cotton and also its strength. From the present study it is clearly seen that it also improves the drape coefficient of the fabric Bleached Materlal It is understood from the term 'bleaching', that it whitens the material. The treatment improves the drape coefficient of the fabric. Bleached material had better drapeablility than the previous processes Dyeing The mercerization process improves the dye uptake of cotton. Its affinity to vat and direct dye is more. For the present study two types of dyes were selected namely direct and vat dye. The drape coefficient between these two dyed materials were studied and found that vat dyed material had better drapeability than the direct dyed material. The reason for vat dyed fabric had better fabric drape this is because the vat dyeing process is not as simple as direct dyeing process. The chemicals involved in this process improve the handling property of the cotton thereby improving the drape quality of the fabric. The finishing process changes the thread density thereby influencing the mechanical properties of the fabric. The dyeing process reduces the interactions and the internal forces, thereby increasing the crimp of the fabric.

8 Thus, the influence of crimp has put forth the present result that is the finishing process improves the drape coefficient of the fabric Effect of Washing on Fabric drape As the garments are frequently washed, the effect of laundry on fabric drape was determined. Each sample was given 30 consecutive washes. It was found that all the five samples exhibited the same trend in the fabric drape. After the first wash there was an increase in the fabric drape coefficient for all fabrics. This may be due to the shrinkage of the material, which might have led to the fabric structural changes. After the second wash there was a decrease in the trend of fabric drape. Though the trend is the same but each fabric behaved in a different manner. This is shown in the Table 8.2 and fig 8.2 Cotton fabric showed a sudden drop in the fabric drape, This may be due to the removal of stiffening agent in the consecutive washes. After the 15' wash there was an increase in the drape behaviour, this is due to the shrinkage in cotton fabric. Similarly, the fabric Sample 1 also behaved in the same manner but the increase in the drape was noted after the 20" washes as the fabric has a very close weave structure (twill). Fabric Sample 2 also almost had the same trend that of the first sample, though it is a blended fabric. This is due to the fabric structure, which causes this trend. On the other hand the fabric sample 4 and 5 showed almost a negligible difference in the drape after the srn wash. A close look at the Figure 8.2 one can see that he fabric Sample 5

9 Table 8.2 Washing and Drape Coeff lclent

10 Figure 8.2 Effect of Washing on Fabric Drape l ' l s l ' l ' l - ~ ' ~ d No.of Washes

11 showed slight increase in the drape after 15" wash. This is due to the blend where cotton is present which has the inherent shrinkage property Comparison of Fabric Drape In Dry and wet &ate The fabrics were sprinkled with water and blotted to remove the excess moisture on the surface of the fabric. This experiment was done as a model of a fabric that has absorbed perspiration. As clothes when attired absorb perspiration, and the effect of perspiration was taken into consideration for the present study. It was found that fabric in wet state had higher drapeability than in its dry state. This is due to the weight gained by the fabric due to moisture content, which in turn increase the drapeability. Fig 8.3 and table 8.3 represents it. The close look at the figure, it can be noted that fabric Sample 5 has the highest drop in drape coefficient in wet state the second comes the Sample 1 and 2 this is because these two are of 100 /~ cotton fabric which is a hydrophilic fibre. The fabric Sample 4 does not have much difference because it is of 100% polyester, which is hydrophobic in nature. The absorbency power of the fabric directly affects the fabric drape in the wet stat

12 Table 8.3 Comparison of Fabrlc Drape in Wet and Dry State

13 Fig 8.3 Drape Coefficient of Fabrics (Dry& Wet State) Sample

14 9, CONCLUSIONS The conclusions are as follows: 1. Every finishing treatment applied to the cotton fabric- scouring, Mercerisation, bleaching enhanced the drapeability of the fabric. 2. Vat dyed material had better drape coefficient than the direct dyed material. 3. After first wash all the fabrics exhibited an increase in drape coefficient. Later, from the second wash, there was a decreasing trend in the drape coefficient. 4. Drape coefficient of the fabric in the wet state had decreased considerably when compared to dry state.