ME3251: Analysis of Stain Resistant Shirt

ME3251: Analysis of Stain Resistant ShirtTan Yu Feng A0097455R

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Stain resistant shirts, or hydrophobic shirts are made of materials that repel both water and dirt. Pouring water, ketchup, or coloured liquid and they simply roll off the fabric. The technology behind this involves changing the nature of surfaces, emulating the hydrophobic properties of the lotus leaf.1Key Material PropertiesLightComfortDurableFlexibleStain ResistantMaterialKey PropertiesPolyesterHydrophobic, low water-absorbency, good durabilitySilicaWater-resistant

What are we looking for in a stain resistant shirt?Polyester: Naturally derived from coal, water, air and petroleum. Polyester is hydrophobic in nature and repels water.Silica: A form of silicon dioxide that is hydrophobic and makes up the shirt at the molecular level using nanotechnology.The polyester fabric forms layers with many silica particles and repells liquid molecules.They roll off due to a lack of attraction, forming a 150 sphere and superhydrophobic surface. Superhydrophobic surfaces have contact angles which exceed 150 and roll-off angle less than 10, also known as the Lotus effect.

2Testing StandardsMaterialDescriptionTesting StandardPolyesterTensile propertiesISO 2062:1993PolyesterResistance to water penetrationEN 20811PolyesterSurface wetting resistanceLVS EN 24920PolyesterSurface contact angleSessile Drop MethodPolyesterAir permeabilityLVS EN ISO 9237:2001SilicaWater repellencyAATCC-22SilicaHydrostatic head pressureAATCC-127

Tensile PropertiesDetermination of single-end breaking force and elongation at break

Resistance to Water PenetrationSubject a specimen to steadily increasing pressure of water on one face until penetration occurs. The hydrostatic head supported by a fabric is a measure of the resistance to the passage of water through the fabric

Surface wetting resistanceSpray test method for determining the resistance of any fabric. A specified volume of distilled water is sprayed on a test specimen mounted on a ring, placed at 45 degree angle so that the centre of specimen is below the spray nozzle. Spray rating determined by comparing the appearance of the specimen with descriptive standards and photographs

Surface contact angle (Sessile Drop Method)By placing a droplet of liquid with known surface energy, the shape of the drop, specifically the contact angle, and the known surface energy of the liquid are the parameters which can be used to calculate the surface energy of the solid sample.

Air PermeabilityInfluence on human heat-exchange processes in clothes.

Water RepellencyMeasures the resistance of fabrics to wetting by water. Water is sprayed against the taut surface of a test specimen under controlled conditions produces a wetted pattern whose size depends on the relative repellency of the fabric. Evaluation is accomplished by comparing the wetted pattern with pictures on a standard chart.

Hydrostatic Head PressureMeasures the resistance of a fabric to the penetration of water under hydrostatic pressure. Water resistance depends on the repellency of the fibers and yarns. 3

ResourcesLow heat from sunlightEmissionsNILResourcesPolyester, SilicaEnergy for material forming and moldingEmissionsCO2,SO2Excess cutoffs (recycled)ResourcesPetroleum for polymerizationFertilizers and PesticideWaterEthanol and ammonia for synthesis of silica nanoparticlesEmissionsCO2,SO2Release of excess nanoparticles to environmentResourcesSpace in landfillEnergy for transportationEmissionsWaste to landfillMaterials (recycled)MaterialManufacturingTransportationUseDisposalMaterial efficiency10222Energy efficiency22221Carbon efficiency21442MaterialManufacturingTransportationUseDisposalMaterial efficiency43243Energy efficiency43324Carbon efficiency42443CottonPolyester

For material production, petroleum is needed for polymerization of polyester Ethanol and ammonia are needed for the synthesis of silica nanoparticlesThe stain resistant t-shirt does not require plenty of washes and can be reworn constantly, they only require sunlight to kill bacteria Taking into account that the polyester shirts are stain resistant and therefore require less wash, this makes polyester the preferred choice over cotton. While polyester is hydrophobic and stain resistant, silica is also selected due to its water-repelling properties and therefore making the shirt more stain resistant. 4Alternative MaterialsPolypropyleneWidely used for furniture and long-sleeve shirtsEasily dyedDurable and flexibleResistant to moisturePolyurethaneUsed for man-made leathers, sports clothing and undergarmentsDurable and flexibleWaterproof properties

PETPPPURTensile Strength (psi)7,000-23,0004,500-18,5006,500-33,000Flexural Modulus350,000-3,000,000210,000-1,500,000230,000-2,000,000Chemical ResistanceFair to GoodExcellentGoodRelative Cost$$$$-$$$$$$$$Alternative materials include polypropylene and polyurethane, both are also widely used in the textile industrypolyester is selected as the primary material due to its reasonable cost and high durability and flexibility. These are important properties for a shirt for comfort and to withstand wear and tear. Also, it does not absorb moisture which is an important property for the stain resistant shirt. 5

Public Health Concerns

Instead of NeverWet, the shirt is made from hydrophobic nanotechnology rather than sprayed on and coated with chemicals, making it a healthier choice. Moreover, this means that it lasts longer than other sprayed-on stain resistant shirts. 6Works Cited[1] Sumitra, "Australian Inventors Create Hydrophobic T-SHirt That Repels Water and Dirt," 7 August 2014. [Online]. Available: http://www.odditycentral.com/news/australian-inventors-create-hydrophobic-t-shirt-that-repels-water-and-dirt.html.[2] "Comfortable Stain-resistant Fabric," [Online]. Available: http://www.teijin.com/rd/technology/dastop/. [Accessed 2015].[3] K. M. Krapp, "How Products Are Made," 2006. [Online]. Available: http://www.madehow.com/Volume-2/Polyester.html. [Accessed 2015].[4] T. Hornyak, "Laugh at spills and sweat with this Silic stain-proof nanotech T-shirt," 13 December 2013. [Online]. Available: http://www.cnet.com/news/laugh-at-spills-sweat-with-silic-stain-proof-nanotech-t-shirt/.[5] Z. A. M. A. T. Tanveer Hussain, "Materials and Methods," Prediction of tensile Strength of polyester/cotton blended woven fabrics, vol. 35, p. 243, 2010.

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ResourcesLow heat from sunlightEmissionsNILResourcesPolyester, SilicaEnergy for material forming and moldingEmissionsCO2,SO2Excess cutoffs (recycled)ResourcesPetroleum for polymerizationFertilizers and PesticideWaterEthanol and ammonia for synthesis of silica nanoparticlesEmissionsCO2,SO2Release of excess nanoparticles to environmentResourcesSpace in landfillEnergy for transportationEmissionsWaste to landfillMaterials (recycled)For material production, petroleum is needed for polymerization of polyester Ethanol and ammonia are needed for the synthesis of silica nanoparticlesThe stain resistant t-shirt does not require plenty of washes and can be reworn constantly, they only require sunlight to kill bacteria

9MaterialManufacturingTransportationUseDisposalMaterial efficiency10222Energy efficiency22221Carbon efficiency21442MaterialManufacturingTransportationUseDisposalMaterial efficiency43243Energy efficiency43324Carbon efficiency42443CottonPolyester

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