Appearance Retention - Moisture Absorbency Moisture...

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Unformatted text preview: Moisture Absorbency Moisture Absorbency We did a simple moisture absorbency test on 5 fabrics in class. If you missed class and want to do this, I have fabric swatches for you. Appearance Retention Appearance Retention Evaluating sewn product appearance following use, care, and weather exposure Refurbishing Textiles Refurbishing Textiles Removal of soil and stains and restoration of appearance Most common are laundering and dry cleaning Dry Cleaning & Laundry Institute, Intl. is a major source of information on refurbishing. (www.ifi.org) They run a textile testing facility They collect information from member drycleaners and launderers They issue reports alerting members to problems – see posted at your dry cleaners Components of Laundering and Dry Components of Laundering and Dry Cleaning Solvent (water or dry cleaning solvents) Often heat Mechanical action/agitation Pressing, blocking, other post cleaning refurbishment Potential refurbishment problems Potential refurbishment problems Change in dimensions and shape Change of appearance through wrinkling, soiling and staining, change of color, loss of finish, change in component parts Subjective Assessment Subjective Assessment Many aspects of appearance retention are assessed using visual evaluation to assign a grade Trained observers, often 3, rate specimens under strictly specified viewing conditions, often light, distance, viewing angle Viewing protocol for rating samples Standards and Replicas Standards and Replicas Specimens are compared to Numbered sets of standard photographs or plastic replica standards with scales from 1 (very poor) to 5 (ideal appearance) Half grades are acceptable Grades from multiple viewers would be averaged Visually Evaluated Properties Visually Evaluated Properties Wrinkle recovery Smoothness after washing Crease retention (pant legs) Seam smoothness Edge wear of flocked fabrics Soil and stain removal Fading Color transfer Dimensional Change During Dimensional Change During Refurbishment Fabrics may change dimensions Can be caused by shrinking growing skewing Agitation, moisture, and heat in washing Agitation and heat in tumble drying Steaming and pressing Relaxation shrinkage Relaxation shrinkage Relaxation of stresses created during weaving or knitting, such as stretching onto a warp, or tentering during printing and finishing Immersion in water, without agitation, can precipitate relaxation Most shrinkage occurs with the first washing – manufacturer preshrinking/compressive shrinking eliminates. Small amount may occur with subsequent launderings Warp yarns typically relax more, explaining shrinkage in length of your jeans Knits shorten and widen when tension pulling loops in the lengthwise direction is removed Fiber and fabric properties affecting Fiber and fabric properties affecting relaxation shrinkage Hydrophilic fibers High yarn twist Unbalanced weaves High fabric count Progressive shrinkage Progressive shrinkage Shrinkage continuing through successive launderings Caused by agitation and water immersion Agitation when wet overcomes frictional forces between fibers, allowing them to move. They extend easily when wet, then retract and entangle when dry Fibers with low wet modulus susceptible: wool, rayon, sot cottons Growth Growth Knits often widen as they decrease in length Some fibers with low wet strength and high elongation extend if line dried, as this causes stretching Thermal shrinkage Thermal shrinkage Thermoplastic fibers can re­shape when exposed to heat, such as hot tumble drying, or ironing Most susceptible are those with low melting points: acetate and olefin Skewness Skewness Same skewness you examined in the fabric inspection lab. Caused by uneven tensions in weaving, or twisting stresses during weft knitting Most susceptible: t­shirts, sweatshirts, twill pants and jeans Testing for dimensional change Testing for dimensional change Measuring length and width before and after cleaning, then calculating percent dimensional change, either negative for shrinkage, or positive for growth Test methods exist for home and commercial laundering, dry cleaning, skewness change, and thread shrinkage (a factor in seam puckering) ASTM performance specifications for ASTM performance specifications for dimensional change after laundering Product Maximum dimensional change, % Men’s and boys woven 3 bathrobes Women’s and girls’ 2.5 woven robes and nightgowns Cotton blankets 5 Bath towels Dishcloths 10 15 ...
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This note was uploaded on 12/25/2009 for the course FSAD 4320 taught by Professor Kozen during the Fall '09 term at Cornell University (Engineering School).

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