CTE 4443 Exam 2 02 21 2013 Things she discussed today in class 4 2 13 WHAT IS DURABILITY It is not a test it is a category of tests KNOW TYPES OF FRICTION TESTING WHAT IS IT WHAT IS PILLING WHY IT HAPPENS AND WHAT FABRICS DOES IT HAPPEN TO ABRASION AND THE DIFFERENT KINDS FLAT ABRASION HOW TO DISTINGUISH SNAGGING WHAT THEY ALL ARE KNITS ARE MORE PRONE TO SNAGGING DON T WORRY ABOUT STRENGTH HOW IS COMFORT DEFINED CAN BE DEFINED BE SOMETHING PHYSICAL OR PSYCHOLOGICAL AND NEED TO HAVE HARMONY TO BE COMFORTABLE DURABILITY MORE IT FAILED COMFORT CONDUCTION CONVECTION MOISTURE WATER REPELLENCY WATER RESISTANCE WATER PROOF HAND REQUIREMENT AND WHY WE DO TESTING FOR FLAMMABILITY FLAMMABILITY COMBUSTION COLOR COLOR FASTNESS CROCKING EVALUATION PROCESS GREY SCALE IS USED TO DETERMINE WHAT CHANGE IN COLOR COLOR CHANGE WHICH TEST DO YOU WANT THE LOWEST NUMBER DIMENSIONAL CHANGE COLORFASTNESS TO LAUNDRY Durability Something that is related to the serviceability wear Things that happen during the wearing process Friction things rubbing together Friction testing describes the resistance to relative motion between two objects in physical contact with each other Usually involves testing for snagging pilling abrasion Testing is assessed as a measure of loss of some part of the material or change in appearance Sometimes assessed by weighing the fabric or visual comparison Pilling results when fibers end or other fiber debris is broken away from surface and becomes entangled with fibers that are still attached to material It is evaluated by using visual comparison between specimen and 5 point photographic rating scale 5 is the best rating no pilling 1 is very severe pilling the accepted level for most apparel is 3 5 Pilling propensity the extent and ease of pilling the likelihood of something happening Pilling resistance resistance to formation of pills on a textile surface Pilling testing evaluates the fabric s resistance to abrasion You will be using the Random Tumble Pilling Tester Abrasion damage caused to a fabric as a result of rubbing against a surface or other material Flat abrasion flat object is rubbed against a flat material this is what we used in lab Flex abrasion the material is bent or flexed during rubbing Edge abrasion material is folded back on itself and rubbed Some retailers establish their own internal performance standards as a tool to provide merchandise acceptable to their customers that may be more stringent than others Snagging Often occurs as fabrics come in contact with rough surfaces or undergo the rubbing process associated with abrasion in actual wear Spun and filament yarns are both prone to snagging Strength resistance to deformation or breakage caused by application of a force one of most common reasons named for testing textiles Tensile strength max resistance of material deformation in a tensile test carried to rupture Bursting strength measures the amount of force required to burst the fabric used on nonwovens and knit force is applied a steel ball or rubber diaphragm is forced through fabric under pressure Seam strength the maximum resistance to rupture at the juncture formed by stitching together two or more adjacent to the stitch line determines optimum sewing conditions stitches stitch type sewing thread Tearing strength a measure of a materials resistance to the continuation of a tear materials must resist the forces of tension folding puncture A fabric which tears easily is usually regarded as inferior Water Repellent fabrics resist penetration by water but are not completely waterproof Waterproof no water can penetrate the fabric Water droplets cannot penetrate some are coated with plastic or rubber Absorbency depends on the same properties fibers yarn fabric finishes your fabric is considered absorbent if it absorbs in 5 seconds or less some fabrics don t need a finish if they have high twist to be repellant Hydrophilic vs hydrophobic Spectral reflectance curve a plot of reflectance vs light wavelength When you can no longer see any reflectance your fabric is considered to have absorbed the water droplet this is why we did the water droplets on the fabric by the window in lab Static electricity usually caused when certain materials are rubbed against each other like wool on plastic or the soles of your shoes on the carpet The process causes electrons to be pulled from the surface of one material and relocated on the surface of the other material Combustion a chemical process in which oxidation produces heat energy Limiting oxygen index the amount of oxygen required to support the combustion of a fiber normal 19 21 Cellulosic 17 20 Wool 25 2 Manufactured 18 20 6 Fibers with LOI above 21 self extinguish Flame resistance the property of material whereby flaming combustion is prevented terminated or inhibited following application of a source of ignition FIRE TRIANGLE In order to have a fire you must have these three elements O2 Fuel Heat Flame retardant finishes work by blocking one leg of the fire triangle usually blocking the oxygen Flammable Fabrics Act Passed in 1953 banned the use and sale of highly flammable materials for clothing Amended in 1967 included carpets draperies bedding and upholstery Consumer Product Safety Commission CPSC they are responsible for recalls on many products regulated by the consumer product safety commission Textile fires result from 1 Mattresses bedding 2 Upholstered furniture 3 Clothing 4 Curtains drapes 5 Carpets rugs 1 cause of textile fires in homes is from smoking in bed Semi durable will withstand a limited number of launderings or cleanings Durable must withstand laundering or other cleaning throughout the expected life of Flame retardant Nondurable water soluble the material Topical added after material is made Solution added in solution when fiber is manufactured More expensive must bond with other chemicals Hand the tactile sensation or impressions that arise when materials are touched squeezed rubbed or otherwise handled Drape occurs when only part of the fabric is directly supported and gravity produces deformation in the unsupported portion there is no standard Some fabrics are known to have no drape jeans have no drape What affects drapability Fiber content fiber structure and yarn structure Heat Transfer phase change heat transfer occurs when an object changes its physical state Liquid to vapor Solid to liquid Vapor to liquid Solid to vapor or gas Normal internal body temp is 98 6F Normal skin temp is 91 92F