**5.4 Loom efficiency and warp and weft tension variations of PET fabrics**

### **5.4.1 Omega and Picanol rapier looms**

Table 20 shows the efficiency and stop number of 2 rapier weaving looms (Omega and Picanol) during weaving PET fabric. Fig.28 shows warp tension according to the warp position on the 2 kinds of rapier looms.


Table 20. Efficiency and stop number of weaving loom during the test

As seen in Table 20, efficiency showed same value as 92% both Picanol and Omega looms, respectively. It is shown that warp breakage of Omega loom was much higher than that of Picanol loom. On the other hand, weft breakage of Omega was less than that of Picanol. The reason why is due to high warp tension of Omega loom and high weft tension of Picanol loom as shown in Fig.28 and 31. As shown in Fig.28, the warp tension according to the full width of Omega loom was much higher than that of Picanol. And the warp tensions of

Fig. 27. The fabric thickness according to the various looms.

**5.4.1 Omega and Picanol rapier looms** 

position on the 2 kinds of rapier looms.

(%)

Loom RPM EFF

Division

OMEGA

PICANOL-GTX

**5.4 Loom efficiency and warp and weft tension variations of PET fabrics** 

Table 20 shows the efficiency and stop number of 2 rapier weaving looms (Omega and Picanol) during weaving PET fabric. Fig.28 shows warp tension according to the warp

470 95.62 2.8 2.8 2.8 8.4 33.3 33.3

465 73.74 39 4 27 70 55.7 5.7 461 98.57 0 0 2 2 0 0 465 97.18 3 0 3 6 50.0 0 461 85.26 0 24 14 38 0 63.2

472 96.85 9.7 2.8 - 12.5 77.6 22.4

466 95.85 3 6 1 10 30.0 60.0 470 94.62 3 2 1 6 50.0 33.3 469 89.44 2 22 2 26 7.7 84.6 461 83.64 2 33 1 36 5.6 91.7

As seen in Table 20, efficiency showed same value as 92% both Picanol and Omega looms, respectively. It is shown that warp breakage of Omega loom was much higher than that of Picanol loom. On the other hand, weft breakage of Omega was less than that of Picanol. The reason why is due to high warp tension of Omega loom and high weft tension of Picanol loom as shown in Fig.28 and 31. As shown in Fig.28, the warp tension according to the full width of Omega loom was much higher than that of Picanol. And the warp tensions of

Average 464.4 92.07 8.8 6 9.6 24.4 36.1 24.6

Average 467.6 92.08 3.4 13 1 17.4 19.5 74.7

Table 20. Efficiency and stop number of weaving loom during the test

Stop number of loom Stop (%) Remark Warp Weft Other Total Warp Weft

WP: 75D

WP: 75D

center parts of the loom were higher than those of both edges of fabric. It is explained that the filling yarn in the middle was held firm and tightly stretched by both sides, as it has to be beaten into the warp ends, in the edge zones, the filling can relax a little from the selvedge, the extent of relax is dependent on the filling insertion system, temples and the selvedge clap, as a result, the filling is woven in a little less firmly in the middle than at the selvedges, this means that they must bind more firmly in the center than at the edges, however the length of all the warp ends coming from the warp beam are practically the same length, those in the middle must elongated more. And it is shown that the average warp tension on center area of the Omega loom is 40~45gf and 35~40gf for Picanol loom, on edge part of the Omega loom is 30~35gf, 25~30gf for Picanol loom, so Omega loom shows 15~20gf higher tension than that of Picanol loom. In addition, high tension variation on edge part of Omega loom is shown, on the other hand tension variation on center part of Picanol loom is also shown. Fig. 29 shows real warp tension variations of Omega and Picanol looms, respectively. It is shown that Omega's warp yarn tension is much higher than that of Picanol. And 4 successive peaks and one high peak are shown both Omega and Picanol looms.

Fig. 28. Warp tension according to the warp position.

Fig. 29. The graph of warp yarn tension of OMEGA and Picanol rapier looms.

The Physical Properties of Woven Fabrics

Loom RPM Efficiency

O m ega Vam atex

10

L 1 L 5 L 1 0 L 1 5 L 2 0 L 2 5 L 3 0

Fig. 32. Warp tension according to warp position

L 3 5 L 4 0

Fig. 33. The variation of warp yarn tension of rapier looms.

L 4 5 L 5 0 L 5 5 L 6 0

four or five successive peaks and one high peak were shown in the Fig. 33.

L 7 0 L 8 0 L 9 0

W arp position (cm )

As shown in Table 21 and Fig. 32, efficiency shows 97.45% and 99.57%, respectively. The warp tensions according to the full width of Omega loom were higher than those of Vamatex. And it was shown that the warp tension of center part of the loom was higher than those of both edges parts of the loom. Fig. 33 shows one cycle warp yarn tension variation of 2 types of rapier looms. As shown in Fig. 33, warp yarn tension distribution in Omega was ranged from 50gf to 60gf, but ranged from 40gf to 60gf for the Vamatex. And

(a) Omega (b) Vamatex

R 8 0 R 7 0 R 6 0 R 5 5

R 5 0 R 4 5 R 4 0 R 3 5 R 3 0

R 2 5 R 2 0 R 1 5 R 1 0 R 5

R 1

20

30

W

arp

tensio n (g f)

40

50

60

70

80

90

(%)

Table 21. Efficiency and stop number of weaving loom for the test

for Emotional Garment According to the Weaving Loom Characteristics 81

Omega 466 97.45 13 3 0 16 81.2 18.8 Vamatex 423 99.57 3 0 0 3 100 0

Stop number of loom Stop (%) Warp Weft Other Total Warp Weft

Fig. 30 shows the shed amount and warp tension of each 10 heald frames at the center part of the loom both Picanol and Omega looms, respectively. As shown in Fig.30, shed amounts both Picanol and Omega looms were increased from front heald to back one even though warp tension of each heald is almost same, but very slowly increased. That means that there is some relationship between shed movement and warp yarn tension on the each heald frame, and it is needed for clean shedding. Fig. 31 shows weft yarn tension variation of Omega and Picanol, respectively. As shown in Fig. 31, weft yarn tension of Picanol was higher than that of Omega. And it was shown that Picanol has distinct 2 peaks but Omega has unstable and subtle 4 or 5 peaks.

Fig. 30. Relation between warp yarn tension and amount of shed.

Fig. 31. The graph of weft yarn tension of Omega and Picanol rapier looms.

#### **5.4.2 Omega and Vamatex rapier looms**

Table 21 shows the efficiency and stop number of two rapier looms (Omega and Vamatex). Fig. 32 shows warp tension according to the warp position on the Omega and Vamatex looms.

Fig. 30 shows the shed amount and warp tension of each 10 heald frames at the center part of the loom both Picanol and Omega looms, respectively. As shown in Fig.30, shed amounts both Picanol and Omega looms were increased from front heald to back one even though warp tension of each heald is almost same, but very slowly increased. That means that there is some relationship between shed movement and warp yarn tension on the each heald frame, and it is needed for clean shedding. Fig. 31 shows weft yarn tension variation of Omega and Picanol, respectively. As shown in Fig. 31, weft yarn tension of Picanol was higher than that of Omega. And it was shown that Picanol has distinct 2 peaks but Omega

has unstable and subtle 4 or 5 peaks.

Fig. 30. Relation between warp yarn tension and amount of shed.

(a) Omega (b) Picanol

Table 21 shows the efficiency and stop number of two rapier looms (Omega and Vamatex). Fig. 32 shows warp tension according to the warp position on the Omega and Vamatex

Fig. 31. The graph of weft yarn tension of Omega and Picanol rapier looms.

**5.4.2 Omega and Vamatex rapier looms** 

looms.


Table 21. Efficiency and stop number of weaving loom for the test

Fig. 32. Warp tension according to warp position

As shown in Table 21 and Fig. 32, efficiency shows 97.45% and 99.57%, respectively. The warp tensions according to the full width of Omega loom were higher than those of Vamatex. And it was shown that the warp tension of center part of the loom was higher than those of both edges parts of the loom. Fig. 33 shows one cycle warp yarn tension variation of 2 types of rapier looms. As shown in Fig. 33, warp yarn tension distribution in Omega was ranged from 50gf to 60gf, but ranged from 40gf to 60gf for the Vamatex. And four or five successive peaks and one high peak were shown in the Fig. 33.

Fig. 33. The variation of warp yarn tension of rapier looms.

The Physical Properties of Woven Fabrics

for Emotional Garment According to the Weaving Loom Characteristics 83

(a) Omega (b) Vamatex

Fig. 36 shows the diagram of relative fabric mechanical properties between Picanol and Omega looms. It is shown that the tensile properties in the warp direction of the fabrics woven by Omega loom were higher than those of woven by Picanol loom, the same phenomena in bending properties were shown, which seems to be due to the higher warp tension of the Omega than Picanol loom. But that tendency was not shown in the weft direction. That phenomena shows that warp yarn tension during weaving on Omega loom affects fabric tensile and bending properties, on the other hand, weft yarn tension on Picanol loom does not affect so much. Contrary to the tensile and bending properties, the shear properties of the fabrics in the warp direction woven by Picanol loom was higher than that of woven by Omega loom, but, in the weft direction, the fabric shear properties woven by Omega loom was much higher than that of Picanol loom. And there was no difference of the compression properties between fabrics woven by Picanol and Omega looms. This result demonstrates that shear deformation of fabrics was combined with deformation of warp and weft yarns, high warp yarn tension during weaving on the Omega loom makes low shear rigidity and shear friction of the fabrics in the warp direction, and high weft yarn tension during weaving on the Picanol loom makes low shear rigidity and shear friction of

(a) warp direction (b) weft direction Fig. 36. The diagram of relative fabric mechanical properties between Picanol and Omera

Fig. 35. The variation of weft yarn tension of 2 rapier looms.

**5.5.1 Comparison between Picanol and Omega** 

the fabrics in the weft direction.

looms.( Picanol: shadow(100%), — : Omega)

**5.5 Fabric physical properties according to the rapier looms** 


Table 22 and Fig.34 show the shed amount and warp tension of each 10 heald frames at the center of the loom both Omega and Vamatex.

Table 22. The shedding amount and warp tension of the test weaving looms

Fig. 34. Relation between warp yarn tension and shed amount.

It is shown that shed amount was increased from 1st heald to 10th one, and warp yarn tension was proportional to the shed amount.

Table 23 shows weft yarn tension and end break of weft yarn on the 2 kinds of looms.

Fig. 35 shows one cycle weft yarn tension variation of the Omega and Vamatex looms.


Table 23. Weft tension and end break of weft on the two looms.

As shown in Table 23, maximum weft yarn tension was 81gf in Omega and 81.3gf in Vamatex, but end break of Omega was 3 and zero for Vamatex. The reason why seems to be due to high weft yarn tension fluctuation in Omega loom which is shown in Fig. 35. As shown in Fig.35, weft yarn tension variation of Vamatex was much more stable and lower compared to Omega loom.

Table 22 and Fig.34 show the shed amount and warp tension of each 10 heald frames at the

Loom 1 2 3 4 5 6 7 8 9 10

VAMATEX Shed amount (mm) 63 68 74 79 83 88 93 98 103 108

Table 22. The shedding amount and warp tension of the test weaving looms

<sup>79</sup> <sup>80</sup>

57 57

<sup>87</sup> <sup>84</sup> <sup>82</sup>

<sup>83</sup> <sup>79</sup>

shed amount (mm) 70 74 78 82 84 87 93 98 97 98 warp tension (gf) 72 71 76 79 80 71 71 78 80 85

Warp tension (gf) 48 51 49 57 57 65 61 66 64 69

93

<sup>66</sup> <sup>65</sup>

61

88

1 2 3 4 5 6 7 8 9 10 H ea ld fra m e

It is shown that shed amount was increased from 1st heald to 10th one, and warp yarn

Loom RPM Max. weft tension Number of end break

As shown in Table 23, maximum weft yarn tension was 81gf in Omega and 81.3gf in Vamatex, but end break of Omega was 3 and zero for Vamatex. The reason why seems to be due to high weft yarn tension fluctuation in Omega loom which is shown in Fig. 35. As shown in Fig.35, weft yarn tension variation of Vamatex was much more stable and lower

Table 23 shows weft yarn tension and end break of weft yarn on the 2 kinds of looms. Fig. 35 shows one cycle weft yarn tension variation of the Omega and Vamatex looms.

Omega-Panter 466 81.0 3 Vamatex 423 81.3 0

71 71

93

98 97 98

64

98

<sup>78</sup> <sup>80</sup>

103

108

0

20

40

W a rp

tensio n (g)

60

80

100

85

69

center of the loom both Omega and Vamatex.

OMEGA -Panter

Heald

78

76

O M E G A S hed am o unt V A M A TE X S hed am o unt O M E G A W arp tensio n V A M A TE X W arp tensio n

74

Fig. 34. Relation between warp yarn tension and shed amount.

Table 23. Weft tension and end break of weft on the two looms.

74

<sup>49</sup> <sup>51</sup> <sup>48</sup>

<sup>72</sup> <sup>71</sup>

68

tension was proportional to the shed amount.

70

0

compared to Omega loom.

20

40

S hed a m o unt (cm )

60

80

100

120

140

160

63

Fig. 35. The variation of weft yarn tension of 2 rapier looms.
