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

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

Age Variety Moisture (%) pH Wax (%) Conductivity Glucose(%) (years)(location) (  -1 cm-1) 0FM832(T) PM2200(T) DP491(G) PHY355(M) PM11218(M) Mean 6.97 a 6.88 a 0.47 a 800 a 0.15 a 2 FM832(T) PM2200(T) DP491(G) PHY355(M) PM11218(M) Mean 6.59 b 6.36 a 0.41 a 768 a 0.04 b Chemical Properties as a Function of Warehouse Storage

Age Variety Length (cm) Strength Unif (%) Rd +b (years) (location) (g/tex) 0 FM832(T) PM2200(T) DP491(G) PHY355(M) PM11218(M) Mean 2.82 a a a a 9.07 a 2 FM832(T) PM2200(T) DP491(G) PHY355(M) PM11218(M) Mean 2.87 a a a a b HVI Properties as a Function of Warehouse Storage

Age Variety Opening Strength Elong (%) Thicks Thins (years) (location) Waste (%) (g/tex) 0 FM832(T) PM2200(T) DP491(G) PHY355(M) PM11218(M) Mean 1.57 a a 7.12 a 616 a 119 a 2 FM832(T) PM2200(T) DP491(G) PHY355(M) PM11218(M) Mean 1.91 a b 6.78 a 579 a 110 a Yarn Properties as a Function of Warehouse Storage

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?

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!

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 a a Treatment17.68 b a *Mann-Whitney rank sum test; P=< 0.001

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 a a Treatment20.24 b a *Mann-Whitney rank sum test; P=< 0.05

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

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) 70C, vacuum-dry, recondition B2) 70C, vacuum-dry, recondition

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 a a A2 (w glucose)15.71 b b *t- test P=< ; 3% increase from A1 to A2

Results-Heat 2 Ring-spun bobbins room temperature (B1) 2 Ring-spun bobbins 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 a a B2 (70 C)13.38 b a *t- test P=< ; 5% decrease from B1 to B2

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

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

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