Wash-and-wear performance

From the standpoint of use in textiles, cotton is rated excellent for hand (general feel, softness, drape), pilling resistance, and stability to repeated launderings. Cotton is rated good for abrasion resistance, strength, wash and wear performance, and wrinkle resistance. Resisiance to sunlight is rated only fair. Pressed-erease retention is rated poor. Safe-ironing temperature for most coiton fabrics is 425°F (2I9°C>. 

Flax fabrics (linen) have an excellent hand, fair abrasion resistance, fair pilling resistance, good stability to repeated launderings, fair sunlight resistance, excellent colorfastness. veiy poor wash and wear performance, and poor wrinkle resistance. 

Monsanto wash and wear standards Standard samples or photographs for wash and wear performance (standard one is worst and five is best smoothness) A fabric is finished, washed, dried in a standard manner and compared subjectively for appearance with a series of five standard samples, using a panel for the test sample with illumination at an angle of indication with the plane of fabric of 10-15 . 

The high-performance rayons overcome this disadvantage. The HWM fiber has cotton like mechanical properties and a caustic resistance that allows mercerization. It is compatible in blends with all grades of cotton where it adds strength, improved luster and appearance, and a softer hand. In blends with nylon, polyester, acrylics, and triacetate, it has good strength retention after resination, and the blended fabrics have superior wash-and-wear performance and resistance to pilling. 

Wear protective gloves, laboratory coat, and goggles. Perform all operations in the fume hood. Dissolve the dinitrosopiperazine (300 pg) in 50 mL of 3 M sulfuric acid (8.5 mL of concentrated sulfuric acid slowly added to 41.5 mL of cold water). Add potassium permanganate (2.4 g), swirl until dissolved, and allow to stand at room temperature for at least 8 hours. If necessary, add additional potassium permanganate to maintain the purple color of the solution. Neutralize the solution by cautiously adding 10% aqueous sodium hydroxide solution, and then add, while stirring, a saturated solution of sodium bisulfite (approximately 10 g of sodium bisulfite per 35 mL of water) until a colorless solution is formed. Wash into the drain with water.4. 

Sample Solution (Caution Perform this procedure in a fume hood, and wear safety glasses.) Transfer 1 g of sample, accurately weighed, into a large test tube. Add 1 mL of nitric acid. Place the test tube in a rack in a boiling water bath. As soon as the rusty tint is gone, add 1 mL of 30% hydrogen peroxide dropwise to avoid a vigorous reaction, and wait for bubbles to form. Stir with an acid-washed plastic spatula if necessary. Remove the test tube from the water bath, and let it cool. Transfer the solution into a 10-mL volumetric flask, and dilute to volume with Butanol-Nitric Acid Solution, and mix. Use this solution for analysis. 

Students should wear safety goggles when performing dissections, heating, or while using acids and bases. Hair should always be tied back and objects should never be placed in the mouth. Food should not be consumed while in the laboratory. Hands should always be washed before and after laboratory experiments. In case of an accident, eye washes and showers should be used for eye contamination or a chemical spill that covers the student s body. Small chemical spills should only be contained and cleaned by the teacher. 

Bromine is a hazardous chemical that may cause serious chemical burns. Do not breathe its vapors or allow it to come into contact with the skin. Perform all operations involving the transfer of solutions of bromine at a hood and wear latex gloves when handling bromine or solutions of it. If you get bromine on your skin, immediately wash the affected area with soap and warm water and soak the skin in 0.6 Msodium thiosulfate solution, for up to 3 hr if the burn is particularly serious. 

Tencel AlOO was launched in 1998 and has proved to be very popular and effective at extending the range of applications for Tencel fibres. It is particularly beneficial for jersey knit applications because of its excellent colouration, attractive aesthetics and good wash/wear performance. The warm touch of jersey fabrics made from AlOO complement the cooler touch of peach skin fabrics made from standard lyocell. 

Because dimethyl sulfate looks like water, operations are preferably not performed when water is present, eg, wet floors or rain. Any spills or leaks should not be left unattended they should be contained, and mnoff to sewers should be avoided. Minor spills should be flooded with water to dilute and hydroly2e the dimethyl sulfate. The area should then be covered with a dilute (2—5 wt %) caustic solution or a dilute (2—5 wt %) ammonia solution, or soda ash may be sprinkled over the neat liquid and the mix wetted with a gende spray of water. The neutrafi2ing agent should remain on the affected area for 24 h and then should be washed away. Only personnel wearing protective equipment should perform these operations. The product bulletins should be consulted for procedures to be followed for more severe spills. Concentrated ammonia should not be used with neat dimethyl sulfate because explosions have resulted after their contact (128). 

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