Welcome to our lecture on evaluating and understanding textile performance this is part one performance and serviceability in this lecture we'll explore four key areas first durability properties including abrasion resistance pilling strength flexibility cohesiveness and elongation these determine how well a textile withstands wear stress and maintains its Integrity over time next is Comfort including absorbency wicking static electricity thermal retention and skin Comfort these properties affect how a textile interacts with heat air and moisture contributing to overall comfort then we'll look at appearance and retention properties which include resiliency compressibility dimensional stability mildew and insect resistance as well as thermoplasticity these ensure that the textile retains its look and feel through use and care and finally we'll look at safety properties including flammability chemical reactivity and environmental resistance these are crucial for ensuring that textiles do not pose hazards and that they withstand environmental factors and ultimately understanding these properties is going to help in choosing the right materials for various applications ensuring that the textiles meet performance standards so first we're going to talk about durability properties these include abrasion resistance pilling strength or tenacity flexibility cohesiveness and elongation and we'll go through each of these one at a time to understand their impact on fabric performance abrasion is a fiber's ability to resist wear from rubbing which includes peeling or thinning of fabric eventually creating a hole we often see this kind of abrasion where Fabrics rub together so for example the inner thigh on a pair of pants or if you carry a bag or a wallet in the same spot against your garment abrasion resistance contributes to fabric durability and there's four types of fabric abrasion the first is flat abrasion and this can be seen where you rub Fabrics against a surface and a hole develops in the clothing so for example if you fall and wear a hole into the knee of your pants that would be an example of flat abrasion or in the example of torn or ripped jeans the clothing company abrs the jeans for you another example of flat abrasion is on the inner thighs of pants like in this picture where there's a small hole that's been worn from abrasion in the inner thighs of these genes next is Edge abrasion and as the name suggest Edge abrasion occurs along the Hem of a garment or the edge of a garment this is where you have abrasion on maybe a cuff a collar or a hem anything that's along the edge of that garment and so it occurs when it rubs against something else it starts to abaid so for examp example it could be the Hem of a cuff or the edge of a pair of pants that are dragging too much along the ground and so the part of the fabric or the Garment that is on the edge is what starts to wear away and this is what we call Edge abrasion next is flex abrasion Flex abrasion happens in something that is moving or bending frequently like in a pair of shoes so if you have a pair of shoes that are bending in the same spot over and over they can start to crack crease or wear away and this happens in shoes that are made of either leather or Fabric and it doesn't have to be shoes it can be anything that bends so it can happen in a pair of pants at the knee or the elbow of a sweater anywhere where the fabric is bending over and over and starts to wear will start to abaid next is pilling pilling is a type of abrasion where fiber ends break and come to the surface and they form tiny little balls of fluff on the fabric surface you can see these tiny fluff balls forming in this knitted Fab fabric here in this image these are actually groups of short or broken fibers and they make the fabric look worn typically cotton pills will fall off the Fabric's surface this is because cotton is a staple fiber with short fibers that fall off easily you can also assist in this process you can get little trimmers that you can shave off the pills on the fabric whereas polyester pills or cotton polyester pills any synthetic blend will use usually stay stuck on the fabric this is because the fibers are long and they don't break off fully and they stick to the fabric more easily so strong fibers will show pilling and weaker fibers pills will eventually fall off a Fabric's durability relates to its tenacity or its strength this is a fiber's ability to withstand stress tensile strength measured in pounds per inch or tenacity measured in per denier is the force needed to break a fiber some fibers are very strong like fiberglass and polyester whereas others are weak like acetate and rayon fiber tenacity can differ between wet and dry Fabrics as well for example cotton is stronger when it's wet but rayon is much weaker when it's wet both strength and abrasion resistance contribute to durability tenacity is measured in several ways in including breaking strength so this is when you're pulling the fabric tearing strength this is ripping and bursting strength this is rupturing or breaking right through the fabric the strongest fibers are nylon and silk whereas some of the weakest fibers are wool and rayon breaking strength is the application of a longitudinal pulling Force to determine the breaking strength which is how much force it takes before it breaks in this image you can see see a weight has been added to the fabric on both sides and as that force is pulled down or pushed down the fabric will eventually tear that point where it tears is the breaking strength tearing strength is the application of a lateral pulling Force at a cut or a small tear in the fabric to determine the tearing strength which is how much force it takes before you can tear it into two pieces and then burst strength is the application of a distending force so this is a force perpendicular to the Fabric's surface and the point where it breaks is the point where we determine the bursting strength essentially you're punching through the fabric flexibility is really important in textiles it's the ability to bend repeatedly without breaking so it's related to the stiffness of the fiber but this does affect the drape of the fabric and ultimately its durability so for example a glass fiber or fiberglass is strong but it has no flexibility so it can be brittle cohesiveness is the ability of fibers to cling together during spinning and resist raveling and slippage cotton fibers are very cohesive but manufactured synthetic filament fibers are not those manufactured fibers don't stick well together so we're going to look at an example here of kok versus cotton so kpo fibers which are obtained from the seed pods of a kpo tree are naturally buoyant and their lightweight and they're often used as a stuffing material however they're not very cohesive kpo lacks the surface structure and length to cling together effectively during spinning and so this makes it less suitable for creating strong durable Yarns or Fabrics whereas cotton fibers on the other hand are highly cohesive their surface structure includes natural twists and a slightly rough texture which helps them cling together during spinning Cotton's cohesiveness makes it ideal for producing strong durable Yarns and fabrics the cohesiveness of cotton fibers contributes significantly to their ability to be spun into fine smooth threads that hold together well enhancing the durability and quality of the finished textile product so understanding the cohesiveness of different fibers helps in selecting the right material for specific applications and ensures that the end product meets the desired performance standards elongation is the stretching of a fiber under a tensile force indicating the amount of strength the fiber can withstand before breaking so for example Kevlar is a fiber that's used in bulletproof vests the way that Kevlar works is it catches the bullet similar to a catcher mitt and these images show the layers of kevlar in a bulletproof vest and how the fabric interacts with a bullet the fabric slows the speed of the bullet and stops it from penetrating through to pierce the skin Kevlar vests are made of multiple layers to enhance protection and here elongation is a crucial factor in the safety of this fabric it impacts its ability to protect the wearer effectively so this brings us to comfort and what is Comfort when we're talking about textiles Comfort describes how a textile product fects heat air and moisture transfer and how the body interacts with the textile product itself we know garments are comfortable when we're unaware of them when we're wearing them so for example care labels care labels are one element of comfort that often receive negative attention due to their scratchiness almost all textile products must have care labels but we can choose different types we can choose printed versus sewn in labels and which one do you think is more comfortable and requires more advanced planning if you purchased a garment with a printed label inside would it be enough for you to continue choosing that brand over another due to the added comfort for some people that would definitely be a motivating factor and there's many indicators that a garment is not comfortable these include feeling too hot too cold too wet too itchy too heavy too constraining and each of these factors affects how pleasant it is to wear the Garment if it's too hot or too cold this is a garment that doesn't regulate temperature well and it can make it uncomfortable for the wearer for example synthetic fibers often trap heat making you feel too warm whereas cotton may not insulate enough in cold weather when a fabric doesn't manage moisture well it can leave the wear feeling clammy or wet Fabrics that absorb moisture but dry slowly can contribute to this discomfort some fibers like wool can feel scratchy or prickly against the skin causing irritation heavy Fabrics can feel cumbersome and resist movement adding to discomfort and then Fabrics that don't have enough stretch or flexibility can feel tight and restrict movement these can make the wear uncomfortable as well so we're going to look at a few Comfort properties we're going to look at absorbency wicking electrical conductivity thermal retention and allergenic potential absorbency in textiles is measured in terms of moisture regain which is the ability of a dry fiber to absorb moisture in a controlled environment that controlled environment is 70° fah and 65% humidity this property is crucial for comfort as it affects how a fabric handles perspiration and exposure to humid conditions so moisture regain this term refers to the percentage of moisture that a dry fiber can absorb relative to its dry weight moisture regain means that the fiber can absorb a lot of moisture enhancing comfort in humid conditions and making the fabric feel less clammy so for example cotton and wool have high moisture regain this means that they can absorb significant amounts of moisture without feeling wet and this makes them comfortable for warm weather or active wear the most absorbent fibers include wool silk rayon and cotton these fibers are known for their ability to take in and retain moisture enhancing comfort in various conditions for example Wool Wool can absorb up to 30% of its weight in moisture without feeling wet this property makes it excellent for regulating body temperature and comfort silk is another highly absorbent fiber that feels luxurious against the skin and helps manage moisture effectively rayon which is a semi-synthetic fiber has high absorbencies similar to natural fibers like cotton and wool it's often used in garments that require a soft and comfortable feel cotton is widely used for its breathability and comfort it can absorb moisture well making it suitable for everyday wear as well as for bedding the least absorbent fibers include Olin polyester and acrylic these fibers are typically synthetic and they do not absorb moisture moisture well which can affect Comfort olant is often used in outdoor and athletic apparel because it repels moisture and it dries quickly however it is not absorbent and it can feel uncomfortable if sweat is not Wicked away effectively polyester is durable and resistant to shrinkage and wrinkles but it is not very absorbent this can make polyester garments feel hot and clammy in warm weather acrylic which is often blended with other fibers to mimic the properties of wool it's less absorbent which can affect Comfort but makes it more resilient to stains and easier to care for so hydrophilic fibers are fibers that absorb water easily and they're water loving all natural and vegetable fibers are hydrophilic as well as rayon acetate and lioel fibers hydrophobic fibers do not absorb water they are water fearing they dry quickly and they generally stain less easily most manufactured synthetic fiber are hydrophobic hydrophobic fibers typically love oil making them oilc so you don't want to drop oily Foods on an old ailc fiber because it will stain hygroscopic is the ability to absorb moisture without feeling wet wool is a very hygroscopic fiber absorbing a lot of moisture without feeling wet this is what makes it great for things like hiking socks now fiber absorbency affects serviceability in several ways this includes skin Comfort wicking static buildup dimensional stability stain removal water repellant wrinkle recovery and thermal or heat retention so we're going to talk about each one of these serviceability aspects High absorbency improves skin Comfort by wicking away perspiration reducing the clammy feeling associated with wet skin this is particularly important for active wear and undergarments Fabrics with good wicking properties draw moisture away from the body to the Fabric's surface where it can evaporate and this keeps the wearer dry and comfortable in Fabrics that do not absorb moisture well they do tend to build up static electricity which often leads to discomfort and clinginess absorbent fibers can help maintain the shape and fit of a garment after washing and drying and they can also reduce shrinkage and Distortion absorbent fibers are often easier to clean as they can take up cleaning agents and water helping to remove stains effectively now while hydrophobic fibers repel water adding finishes to hydrophilic fibers can enhance their water repellent properties for specific applications with respect to wrinkle recovery Fabrics that absorb moisture well can also recover from wrinkles more easily maintaining a smoother appearance and then finally absorbent fibers like wool provide good insulation they retain body heat and they keep the wear warm in cold conditions now we will delve into each of these serviceability factors so skin Comfort is crucial as it affects how the wear feels throughout the day people sweat during the day and fabrics that absorb moisture effectively can help with sweat management they can help vent a clammy feeling wet skin is prone to fungal infections so Fabrics that Wick moisture away from the skin can help prevent such conditions by keeping the skin dry as well Fabrics that allow air to circulate and moisture to evaporate enhance Comfort especially in warm and humid conditions so breathable Fabrics like cotton wool and linen are preferred for this reason and then finally the feel of the fabric against the skin skin including its softness and its smoothness affects Comfort natural fibers like cotton and silk are often chosen for their Pleasant texture wicking is the ability of a fiber to transfer moisture along its surface similar to how an oil burning lamp moves oil up a cotton wick in clothing wicking allows perspiration to be transported along the fiberous surface to the outer surface of the fabric where it will evaporate this process brings brings more Comfort to the wear by keeping them dry and cool so for example cotton cotton as we've talked about is hydrophilic meaning it absorbs water well and it also has good wicking abilities whereas Olin as we discussed is hydrophobic and does not absorb water it can have good wicking abilities when it's in a microen size so this does make it a good choice for exercise clothing because it effectively Wicks away sweat keeps the wearer dry static electricity is a frictional electric charge caused by rubbing together two dissimilar materials this results in Fabrics that cling attract dirt and lint and might even spark when moved now moisture can help dissipate static buildup therefore more absorbent fibers like cotton or wool will not build static electricity as easily epitopic fibers contain carbon or metal which conduct electricity and remove static buildup they are often used in Carpeting and other environments where static electricity can be problematic static electricity can be particularly problematic in environments like hospitals where highly flammable materials are stored a spark from static buildup could start a fire making the use of the right fiber crucial for safety dimensional stability and shrinkage refer to a Fabric's ability to maintain its original size and shape during use and care hydrophobic fibers such as polyester generally shrink less during washing in contrast hydrophilic fibers like cotton and wool are more prone to shrinkage due to fiber swelling so for example wool's fiber structure with its natural scales further contributes to this shrinkage effect this image shows a knitted garment that has become slightly smaller after washing illustrating shrinkage Fabrics that absorb water easily are typically more susceptible to this issue it's easier to remove stains from hydrophilic fibers because water and detergent are absorbed into the fiber allowing the soap to battle the stain effectively hydrophobic fibers have an affinity for the chemicals used in water repellent Coatings and finishings making them effective for such treatments while they resist water-based stains oilbased stains can be more difficult to remove from hydrophobic fibers okay now we're going to move on to fiber structure fiber structure influences insulation which is crucial for maintaining core body temperature the ideal temperature for the human body is 37° C or 98.6 de fit and a variation of up to 2° C above or below this temperature can result in death death thermal retention is the ability of a fabric to hold heat significantly affected by yarn and fabric structure insulation is achieved through clothing that creates tiny pockets of air to insulate us from the environment whether keeping us cool or warm still air is the key to insulation providing surface for air to cling to good insulators create many surfaces for air to be trapped in and around thick fi or those with crimp and curl like wool create Fabrics with better coverage than straight thin fibers irregular surfaces improve insulation because fibers cannot lay against each other fabric thickness and color also play a role in insulation with darker colors retaining more heat wool's natural properties including its crimp and Hollow core make it an excellent thermal insulator water plays a crucial role in heat loss especially with wind water replaces still air within the fiber and fabric weave and wind blows that still air out reducing insulation water interacts with fibers in three ways one absorption so into the fiber two adsorption so it's held on the outer surface and three wicking transported along the surface irritant fibers include stiff fibers stiff Fabrics scrap scratchy labels and coarse wool wet fabric increases friction and increases irritation on the skin coarse wool fibers have shingle like scales that can irritate the skin while finer wool fibers are less irritating now we're going to talk about appearance retention properties these include resiliency compressibility dimensional stability which we've already discussed mildew and insect resistance and thermal plasticity so wrinkles are kind of complex wrinkles occur at a molecular level when heat breaks the bonds that hold polymers in place within a fiber and this allows them to shift as the fabric cools new bonds are formed locking fibers into a new wrinkled shape ironing can remove these wrinkles by breaking and reforming these bonds resiliency is the ability of a fiber to spring back into its natural position after folding or creasing requiring less ironing wool nylon acrylic and polyester are highly resistant Fabrics meaning they return to their original shape after being folded or creased and this reduces the need for ironing on the other hand Fabrics like flax cotton linen rayon these are less resilient and they tend to wrinkle more easily compressibility is the resistance to crushing so this is the ability of a fiber to Spring bring back to its original shape and thickness after it's been flattened or compressed this is known as compressional resiliency or Loft Fabrics with good compressional resiliency maintain their appearance and structure over time even after being subjected to pressure or weight this property is especially important for items like cushions mattresses and certain types of clothing mildew and insect resistance are essential factors in maintaining the appearance of textiles over time time these properties help ensure that Fabrics remain visually appealing and structurally intact mildew is a type of fungus that thrives in warm dark and damp environments it often appears as small splatter spots and emits a musty smell mildew particularly affects soil garments stored in poor conditions with low ventilation and low light cotton is highly susceptible to mildew growth due to its natural composition and ility to retain moisture this makes it crucial to handle cotton Fabrics with care to prevent mildew development to prevent mildew ensure that garments are thoroughly dried before storage store textiles in well ventilated lighted areas as well now only chlorine bleach can effectively kill mildew but it can't be used on certain Fabrics like wool silk Spandex and some nylons due to the risk of damage moths and carpet beetles are the primary insects that damage textiles particularly those that are made from protein fibers like wool leather feathers hair and silk silver fish Target cellulose fibers such as cotton and flax especially in warm humid and dark conditions moth and carpet beetle damage manifests as small irregular holes on the fabric silverfish damage is similar but often it's more prevalent in environments with high humidity and warmth silverfish attack cellulose fibers like cotton and flax and they prefer warm humid damp and dark places they are most active at night they also like Silk and starched linens to prevent insect damage fabric should be stored in clean dry and well ventilated spaces regularly they need to be inspected and storage areas need to be clean to deter insect infestations environmental conditions also affect fiber performance for example sunlight can degrade fibers nylon and silk for example lose their strength when they've been exposed to sunlight and in general ultraviolet light Fades Fabrics this is important for items like car upholstery tents outdoor carpeting as well as drapery which are frequently exposed to the sun glass fibers acrylic and polyester they have excellent light retention whereas fibers like Silk nylon and wool have poor light retention chemical reactivity refers to the effect of chemicals on fibers so some examples of chemical reactivity are acetone acetone is found in nail polish remover and it dissolves acetate fibers perspiration can be become acidic and so it can stain clothing hair products and perfumes can cause a different reaction so they can react with dyes and they can cause discoloration and then sulfuric acid sulfuric acid damages nylon and acids in paper can discolor fabric stored in them thermoplasticity refers to a fibrous ability to soften or melt when it's exposed to heat this property is particularly significant for manufactured fibers which can be manipulated through heat to achieve various desirable effects in textiles thermal plastic fibers can be softened and reshaped using heat a process that is integral in various stages of fabric production this includes dying singing which is the burning off of surface fibers for a smoother finish and heat setting controlled heat application allows for the setting of permanent pleat and creases in Fabrics this process ensures that garments retain their shape and their structure even after repeated washes and wears this enhances their appearance and their functionality thermoplasticity contributes to fabric stability it makes them less prone to shrinkage and more resistant to wrinkles this property is especially valuable in garments that need to maintain a crisp and professional appearance with minimal maintenance during the heat set process Fabrics are exposed to controlled heat which softens the fibers they are then shaped and cooled locking them into the desired configuration this technique is used to create permanent creases in trousers pleat and skirts molded bra cups among other applications the ability to set permanent shapes and resist wrinkles significantly extends the lifespan of a garment thermoplastic fibers maintain their appearance and structure better than natural fibers under similar conditions so garments that are made from thermoplastic fibers require less ironing and special care this makes them practical for everyday wear and easy maintenance flammability is a crucial safety property of textiles and it determines how a material reacts to Fire and its potential to ignite burn or extinguish understanding flammability and flame resistance is essential for selecting materials for environments where fire hazards are a concern the ability of a material to catch fire and burn refers to its flammability highly flammable Fabrics can pose significant safety risks in various settings including industrial home and public spaces flame resistant Fabrics are designed to resist ignition and prevent the spread of flames as you can imagine these Fabrics provide critical protection for workers exposed to fired hazards like firefighters Industrial workers or military personnel flame proof Fabrics are treated or manufactured to be completely non-flammable they do not support combustion and they're used in highly specialized applications where absolute fire safety is required this example here is the thermal man it's a life-size mannequin that was developed by Dupont and the US military in the 1970s to test the effectiveness of flame resistant PPE equipped with 122 heat sensors thermal man is dressed in test garments and exposed to simulated flash fire conditions the sensors record the temperature rise on the mannequin surface and the data predicts the total body area degree and location of burn injuries this information helps designers improve the flammability resistance and the durability of garments this information helps designers improve the flammability resistance and the durability of garments made from materials like NX nomax is a heat and flame resistant synthetic fiber chosen for its use in protective clothing such as firefighter gear and racing suits due to its durability and ability to withstand extreme temperatures so this brings us to the end of our video on performance and serviceability of textiles please take a moment to review your notes before moving on to part two product development