Who Essay, Research PaperLITERATURE OF REVIEWWHY DO SKATEBOARDERS SHOES WEAR OUT SO FAST?Through out skateboarding history a sand paper stuff known as clasp tape has been glued to skateboard decks.
This stuff made for gripping onto boards besides destroys gym shoe colloidal suspensions. Grip tape causes clash between gym shoes and itself, while doing a clasp and easing control of the board. Bicycling wears out gym shoes like walking, but at more accelerated rates ; much higher than walking. Becoming more circwnspect, there is the factor of increased motion on the board such as turning your lead pes ( by and large for most people the left pes, unless they skate cockamamie pes ) back and Forth in between bicycling. With the clasp tape being really farinaceous and necessary for skateboarding, it invariably and easy scrapes off at gum elastic colloidal suspensions, doing gym shoes wear out faster than in any other athleticss or avocations. With this job of gym shoes have oning out fast and being discarded, the skateboarder with limited fiscal resources suffers to boot from the losingss.WHY IS GRIP TAPE NECESSARYThe clasp tape is needed for a skater to keep control over the board by the agencies and the utilizations of clash, Unforttmately grip tape helps have on at the ollie country ( an country of the shoe that is merely behind a individual & # 8217 ; s smallest toe on the outer side of the pes ) and the exclusive quickly.
Grip tape is necessary for street skating fast ones ( illustrations: ollies, kick somersaults, nose swots and nollies ) and ramp skating. If there was no clasp tape vert skaters ( skateboaders who skate on inclines ) would lose control over their board easy, there by raising the hazard of danger and serious accidents. Vert skating is already instead hazardous. Who needs more broken castanetss? Street skaters depend on their clasp tape for particular moves like rail sliding, when they must keep a perfect balance and control of their board or they risk falling on their face or skiding down the remainder of the rail on their groin country, OUCH!IS KEVLAR THE ANSWER?Kevlar, being an aramid fibre that on a weight-by-weight footing proves to be 5 times stronger than steel, makes for a possible reply. All though there are new aramid fibres that are stronger in certain standards, Kevlar was chosen because of its huge popularity and merchandise cognition if the gym shoe colloidal suspensions were to be marketed. Many snowboarding baseball mitts are covered with Kevlar. This application relates to skateboarders since many of them snowboard in the winters and have merchandise cognition of the fibre. Other fibres that are besides applicable for this state of affairs are Akzo & # 8217 ; s Arenka ( aramid ) , Celanese & # 8217 ; s Vectra ( thermotropic copolyesters ) , Dart & # 8217 ; s Xydar ( thermotropic copolyesters ) , and Allied-Signal & # 8217 ; s Spectra 900 ( high modulus polythene ) .
HEAVY COMPETITIONA few old ages ago competition was so high between these companies that Allied-Signal filed a suit against DuPont in 1991, bear downing them with false advertisement and illicitly monopolising the market. The issue was raised since the National Institute of Justice ( NIJ ) , a subdivision of the Department of Justice raised their criterions for slug cogent evidence waistcoats. The NIJ tested their current provider & # 8217 ; s ( DuPont ) merchandise which was produced from Kevlar and Allied-Signals Spectra Shield which uses Spectra 900, with a nine-millimeter gun on a 30 grade angle, there were amazing consequences: Less than 50 per centum of the Kevlar waistcoats passed, while 97 per centum of the Spectra Shield waistcoats did base on balls.WHAT EXACTLY IS KEVLAR?In the early 70 & # 8217 ; s DuPont introduced aramids under trade name of Kevlar and Kevlar 49, besides fon-nerly known as Fiber B and PDR-49.
These fibres and Kevlar 29 do non run, for all practical intents, other than at temperatures affecting decomposition. They are about indissoluble. Therefore doing conventional melt polymerisation and thaw whirling non executable. Kevlar is made by the spinning of fibres from liquid crystals in a solution exhibiting a decreased viscousness, with increasing solids content as the solution becomes anisotropic. By pulling the stuffs at somewhat elevated temperatures, the modulus ( stiffness ) may be increased from 59 to 124 GPA, the values for Kevlar and Kevlar 49. Kevlart thaws at over 500 grades Celsius, is exceptionally high in strength with a doggedness more than twice that of high strength nylon or polyester, and a really high modulus.
The constructions of these fibres are extremely crystalline. Kevlar & # 8217 ; s denseness of 1.44 g/cm cubed is among the highest for organics, while molecular weight of its PPTA ( pphenyleneterephthalamide ) molecules are considered instead low. Although some inside informations of the crystal construction of Kevlar have been uncovered by X raies, a comprehensive theoretical account does non be. Recent surveies of crystallites in Kevlar show that the crystallites are somewhat misaligned due to the fibre axis, but can be oriented by a tensile burden. Since Kevlar has low compressive strength, it can knot from compressive failure due to collapsed zones.
Because Kevlar has a fibrillar construction, it splits axially over distant lengths, unlike most other high strength fibres that break consecutive across. To fracture the stuff, a cleft must track over different planes. With fibrillar break, it makes cutting by machine tools or missiles hard.
Therefore doing it first-class stuff to bring forth slug cogent evidence waistcoats and helmets. Unfortunately since Kevlar is a polymer held together by an amide bond, it is degraded by UV ( UV ) rays.WHY THE Z PLANE IS THE WAY TO GO?With an X, Y plane, the strength of the Kevlug relies on the interrupting opposition of the fibre. Breaking strength for Kevlar is low because Kevlar fibrils are little, therefore doing the X, Y plane a bad pick. With the Z plane, the polymers that would hold been scraped away are left integral, doing wear occur at a slower rate. With a Z plane, one wears the fibre out slower ( something along the lines of molecule by molecule ) , like an eraser caput would by wipe outing something, alternatively of rupturing the eraser in half.
With the Z plane you are seeking to interrupt interior polymer bonds.WHY DOES KEVLAR ONLY MAKES A SMALL DIFFERENCEWHEN BONDED TO RUBBER?First, adhering a matrix fibre to a elastomer is really expensive. The gum elastic, have oning off faster than the Kevlar, causes filmnents of Kevlar to fall out, leting the gum elastic to have on out moderately fast. Unless the narration is a continues twine, the fibres will fall out. When making this, eachsole would hold to be impregnated individually, doing for a much higher monetary value.
The impregnation merely makes a little difference in scratch when compared to rubber entirely. Kevlar would be a good pick when used to better sfiffiess ( utilizing a simlar method that is used on tyres ) After the gum elastic wears off, one is merely left with the fabric that would have on away rapidly from scratch.PROBLEM STATEMENTThrough out skatboarding history, many skaters have had to throw out a new brace of gym shoes within a month & # 8217 ; s wear.
This rapid disposal is due to abrassion with the clasp tape. The clasp tape is sand paper like stuff with an adhisive backup. The clasp wears at two specific points quickly. The two musca volitanss being, the ollie country, an country of the shoe that is merely behind a individual & # 8217 ; s smallest toe on the outer side of the pes, and the outer gym shoe sole. The ollie country is worn away when you do a basic move known as the ollie. When you ollie, the board will foremost get down to travel verticle, so when you slide your pes up the board to get down to travel the board horizontly to put your hieght. During the clip when a individual begins to travel the board horizontally they wear off the leather, nylon, gum elastic, or cotton off a if they were brushing their places with emery paper. Abrasion on the colloidal suspensions is produced from changeless motion of the colloidal suspensions with either clasp tape or the land surface.
With grip tape and most surfaces suited for skateboarding being really farinaceous or unsmooth colloidal suspensions tend to have on like an eraser invariably in usage, therefore causes loss of gum elastic fillaments.HypothesisWith my general cognition of skateboarding and my new cognition of Kevlar and Wearforce I beilieve they will do a suited merchandise for demands of skateboarding. I strongly believe this because overtime Kevlar has been proven to be a strong and lasting stuff, and I do non believe DuPont would blow so much clip on the Wearforce if it fails to make what they designed it for, abbrasion ressitance.
With these factors into consideration I believe my experiments will succseed and boom.ProcedureFor the procedure of proving the Wearforce, Richard Gould ( DuPont representative ) and I decided on processs. We finalized on utilizing a Wyzenbek scratch trial and a Taber scratch trial. To guarantee proper consequences, I planned to prove the stuff in action during a skateboard activity.
During a Wyzenbek trial a piece of 40 grit sand paper by gesticulating back and Forth at 90 rhythms a minute while the stuff being tested is pushed into the emery paper. The emery paper is pushed down by precisely four lbs of force per unit area, while six lbs of tenseness is being applied to the proving stuff. After every 1,000 rhythms, the emery paper is changed.A Taber trial, being less aggressive, merely uses a base on balls or fail sitituation.
If the stuff passes 5,000 rhythms, so it passed, if non it fails. Alternatively of utilizing emery paper during the trial as an abradant, an scratchy spinnig wheel is used.Bing most simplistic of all I planned to travel skateboarding with the Wearforce on the ollie country of my shoe. Tormenting my sesion, I performed the undermentioned moves, an oille and kickfllp. These fast ones were reapeated to guarantee satisfaction in the merchandise.Materials* 40 grit emery paper* Wearforce 9gym shoe leather* boot leatherWyzenbek proving mahine* Taber testing machine* contact cement* skate places* skateboardConsequenceWhen the trials were selected, I had learned that my trial planned for the Kevlar had already been performed, and failed, due to the factors of cost and small betterment in lastingness. Fortunately, my other trials were original. The Wearforce went from 15,000 to 20,000 rhythms in the Wyzenbek trial compared to sneaker leather & # 8217 ; s 1,000 to 1,500 rhythms, and boot leathees 2,000 to 5,000 rhythms.
In the Taber trial, Wearforce passed with over 100,000 rhythms. Last, from skateboarding with the Wearforce on my gym shoes, it was learned that Wearforce is much more lasting when compared to leather, and does non give off an unwanted grippy feel.DecisionWith the acquired consequences of Kevlar & # 8217 ; s failure and Wearforce & # 8217 ; s success, my hypothesis is at the same time rejected and supported.
Kevlar failed due to high cost and hapless public presentation testing ; where as, Wearforce succeeded in protecting the ollie country of a skate-boarding shoe at an economical cost without any drawbacks to the maker.