using the draftometer for ring spinning improvements c.d ...€¦ · – uster tester cv%,...
TRANSCRIPT
![Page 1: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/1.jpg)
Measurement and Control of Drafting Forces: Using the Draftometer for Ring Spinning
Improvements
C.D. DelhomUSDA‐Agricultural Research Service
Cotton Structure and QualityNew Orleans, LA USA
![Page 2: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/2.jpg)
Draftometer?
• Measures drafting forces• Used to determine critical draft
– Critical Draft?• Draft at which the fiber strand becomes highly unstable• Also known as “stick‐slip”
• ITT work concluded that break draft should be set 10% below critical draft– In lieu of changing break draft, roving twist can be adjusted to move critical draft at a given break draft
![Page 3: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/3.jpg)
Draftometer
Schematic from “Short Staple Manufacturing” McCreight, et al
![Page 4: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/4.jpg)
![Page 5: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/5.jpg)
Critical Draft• Factors known to impact critical draft:
– Roving size– Twist– Tension
• Unknown factors:– Fiber quality
• Length• Fineness• Surface characteristics?
– Convolutions?– Frictional properties?
![Page 6: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/6.jpg)
Critical Draft
‐0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
30 130 230 330 430 530 630
Failed
Passed
![Page 7: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/7.jpg)
Motivation• Properly constructed roving produces more uniform yarns with decreased ends down
• Break Draft can be difficult to change– Gearing/roll spacing on spinning frame– Draft distribution concerns
• What is appropriate roving twist?
• Draftometer is sensitive and time consuming
![Page 8: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/8.jpg)
Previous Work
• Mill trials have shown occasional inconsistencies in draftometer results between replications of lots
• What role do fiber properties play in determining drafting forces?
![Page 9: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/9.jpg)
Method• Full bale quantities were carded and drawn• Draftometer used to determine optimum twist level for 1.0 hank roving draft for each cotton– 7 twist levels of roving to be produced for each cotton
1. Use twist gear for optimum twist level2. Critical Twist gear +1 tooth3. +2 teeth4. +3 teeth5. Critical Twist gear ‐1 tooth6. ‐2 teeth7. ‐3 teeth
![Page 10: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/10.jpg)
Method
• 3 doffs of Ne 30/1 with 3.8 TM @ 16,000 rpm• Ends down recorded
– Quantity, position and type of ends down
• Yarn Quality – Uster Tester CV%, Tenacity, Classimat
![Page 11: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/11.jpg)
Draftometer Results
Cotton Twist Gear Twist Multiple
1 38 1.33
2 32 1.58
3 31 1.63
4 38 1.33
5 38 1.33
tpi = TM *(Roving Hank)1/2
Twist gear as determined by Draftometer: Critical draft – 10%Break Draft fixed at 1.31
![Page 12: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/12.jpg)
Hard Ends
0
100
200
300
400
500
600
700
‐3 teeth ‐2 teeth ‐1 tooth CriticalDraft
+1 tooth +2 teeth +3 teeth
Ends Dow
n pe
r 1000 spindle ho
urs
Twist Setting
Cotton 1
Cotton 2
Cotton 3
Cotton 4
Cotton 5
Less Roving Twist
![Page 13: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/13.jpg)
Yarn Uniformity
14
15
16
17
18
19
20
21
22
23
‐3 teeth ‐2 teeth ‐1 tooth CriticalDraft
+1 tooth +2 teeth +3 teeth
CV(%
)
Twist Setting
Cotton 1
Cotton 2
Cotton 3
Cotton 4
Cotton 5
Less Roving Twist
![Page 14: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/14.jpg)
Yarn Strength
5
7
9
11
13
15
17
19
‐3 teeth ‐2 teeth ‐1 tooth CriticalDraft
+1 tooth +2 teeth +3 teeth
Tena
city (cN/tex)
Twist Setting
Cotton 1
Cotton 2
Cotton 3
Cotton 4
Cotton 5
Less Roving Twist
![Page 15: Using the Draftometer for Ring Spinning Improvements C.D ...€¦ · – Uster Tester CV%, Tenacity, Classimat. Draftometer Results Cotton TwistGear Twist Multiple 138 1.33 232 1.58](https://reader036.vdocument.in/reader036/viewer/2022062416/61046f774491c679b605ecda/html5/thumbnails/15.jpg)
Conclusions• Further work is needed to asses the ‐10% recommendation
• Differences between front and back roving frame positions do exist due to tension
• Role of tension changes with package size needs to be examined
• No clear fiber property /drafting force interaction understood at this time
• More work is needed!