1. The Effect of Fiber Surface Sugar Content on Yarn Properties Gary R Gamble USDA-ARS-CQRS Clemson, SC

2. Introduction  Replicate bales of cotton studied both before warehouse storage (0 years) and after warehouse storage (2years)  Chemical properties: moisture, surface salts (conductivity), glucose, pH  HVI properties  Yarn properties

3. Age Variety Moisture (%) pH Wax (%) Conductivity Glucose(%) (years)(location) (  -1 cm-1) 0FM832(T) 7.20 6.12 0.65 1025 0.28 PM2200(T) 6.93 6.37 0.57 967 0.17 DP491(G) 6.80 6.75 0.38 692 0.16 PHY355(M) 6.83 6.91 0.44 717 0.09 PM11218(M) 7.10 8.24 0.29 600 0.05 Mean 6.97 a 6.88 a 0.47 a 800 a 0.15 a 2 FM832(T) 6.50 5.71 0.67 900 0.07 PM2200(T) 6.62 6.10 0.46 920 0.05 DP491(G) 6.63 6.33 0.36 680 0.05 PHY355(M) 6.61 6.36 0.28 720 0.03 PM11218(M) 6.60 7.30 0.27 620 0.01 Mean 6.59 b 6.36 a 0.41 a 768 a 0.04 b Chemical Properties as a Function of Warehouse Storage

4. Age Variety Length (cm) Strength Unif (%) Rd +b (years) (location) (g/tex) 0 FM832(T) 3.00 29.74 80.28 78.38 9.59 PM2200(T) 2.79 27.75 81.19 80.41 9.25 DP491(G) 2.87 30.59 80.25 77.34 8.20 PHY355(M) 2.82 29.31 82.00 74.00 8.57 PM11218(M) 2.67 26.26 81.88 74.19 9.72 Mean 2.82 a 28.73 a 81.12 a 76.86 a 9.07 a 2 FM832(T) 3.07 29.40 81.50 74.60 13.60 PM2200(T) 2.82 27.67 83.04 77.99 12.03 DP491(G) 2.90 30.80 81.70 76.75 11.10 PHY355(M) 2.87 28.90 82.10 74.20 10.00 PM11218(M) 2.64 26.00 82.00 74.97 11.34 Mean 2.87 a 28.55 a 82.07 a 75.70 a 11.61 b HVI Properties as a Function of Warehouse Storage

5. Age Variety Opening Strength Elong (%) Thicks Thins (years) (location) Waste (%) (g/tex) 0 FM832(T) 1.14 18.78 7.23 712 21 PM2200(T) 0.96 17.16 7.74 611 66 DP491(G) 2.78 18.25 6.87 684 129 PHY355(M) 1.73 17.00 7.41 587 192 PM11218(M) 1.24 16.50 6.33 487 189 Mean 1.57 a 17.54 a 7.12 a 616 a 119 a 2 FM832(T) 1.39 17.57 6.78 535 57 PM2200(T) 1.21 15.55 7.35 670 123 DP491(G) 3.41 17.03 6.52 657 102 PHY355(M) 1.94 15.54 7.07 555 132 PM11218(M) 1.60 14.95 6.17 482 138 Mean 1.91 a 16.13 b 6.78 a 579 a 110 a Yarn Properties as a Function of Warehouse Storage

6. Observations  8% Yarn strength decrease associated with moisture, glucose and (possible) wax decreases due to heat and microbial growth  Decrease in yarn strength accompanied by +b increase, but no change in HVI strength  Is yarn strength correlated with surface chemical (glucose, wax) properties?

7. Controlled Experiment to Test Correlation of Glucose with Yarn Strength  Spray glucose onto cotton stored in bale form for > 2 years  Spin control cotton and sprayed cotton into 22/1’s yarn via miniature ring spinning  Spin control cotton and sprayed cotton into 20/1’s yarn via full scale (50 lb lot) ring spinning  WARNING: DO NOT TRY THIS AT HOME!

8. Results: Mini-Spinning 100g untreated (control) 100g sprayed with 0.1%(w/w) glucose in water (Treatment) 22/1’s ring yarn on miniature spinning 200 yarn breaks Strength(g/tex)*CV%Elong.(%) Control16.98 a7.654.94 a Treatment17.68 b9.454.96 a *Mann-Whitney rank sum test; P=< 0.001

9. Results: Pilot Spinning 50 lb sprayed with water (control) 50 lb sprayed with 0.1%(w/w) glucose in water (Treatment) 20/1’s ring yarn on pilot spinning 1000 yarn breaks Strength(g/tex)*CV%Elong.(%) Control19.66 a8.106.12 a Treatment20.24 b8.155.70 a *Mann-Whitney rank sum test; P=< 0.05

10. Conclusions  Application of glucose to aged cotton results in a ~3-4% increase in yarn strength  Strength increase observed is not sufficient to explain 8% loss upon ageing of cotton in bale form

11. Pre-spun Yarns Pre-spun Yarns  20/1’s yarns wound from same roving and ring spinning spindles  Yarns treated by: A1) soak in H 2 O:benzoate, freeze-dry, recondition A1) soak in H 2 O:benzoate, freeze-dry, recondition A2) soak in H 2 O:glucose:benzoate, freeze- dry, recondition A2) soak in H 2 O:glucose:benzoate, freeze- dry, recondition B1) vacuum-dry, recondition B1) vacuum-dry, recondition B2) heat @ 70C, vacuum-dry, recondition B2) heat @ 70C, vacuum-dry, recondition

12. Results-Glucose 2 Ring-spun bobbins treated w. water:benzoate (A1) 2 Ring-spun bobbins treated w. water:glucose:benzoate (A2) 20/1’s ring yarn on pilot spinning 200 yarn breaks Strength(g/tex)*CV%Elong.(%) A1 (w/o glucose)15.20 a7.716.40 a A2 (w glucose)15.71 b8.156.82 b *t- test P=< 0.001 ; 3% increase from A1 to A2

13. Results-Heat 2 Ring-spun bobbins treated @ room temperature (B1) 2 Ring-spun bobbins treated @ 70C (B2)* *HVI values on raw cotton control vs treated at 70C are not significantly different except for +b 20/1’s ring yarn on pilot spinning 200 yarn breaks Strength(g/tex)*CV%Elong.(%) B1 (no heat)14.04 a6.905.74 a B2 (70 C)13.38 b8.455.84 a *t- test P=< 0.001 ; 5% decrease from B1 to B2

14. Comparison of Gas Chromatograms of Heat Volatile Components Of New and Aged Cottons

15. Conclusions  Surface sugars and waxes are correlated with yarn strength  Aged cottons exhibit decreased sugars and loss of wax constituents: resulting loss in yarn strength  Field weathering poses the same implication via heat and rain effects  Other than +b, no HVI indicators

16. Conclusions  The observed changes appear to be irreversible in practical terms  Measurement of wax constituent ratios may be a potential method for indicating yarn performance-subject of ongoing work Thank you