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dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
dissertation interim Presentation
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dissertation interim Presentation

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the affect of weathering on climbing sling strength. …

the affect of weathering on climbing sling strength.

final year project

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  • 1. The Effect Of Weathering On Climbing Sling Strength Steven Clench Loughborough University
  • 2. Contents <ul><li>What is a climbing sling? </li></ul><ul><li>Abseil anchors </li></ul><ul><li>Weathering </li></ul><ul><li>Measurements to be taken </li></ul><ul><li>What results are expected to show </li></ul>
  • 3. What Is a Climbing Sling <ul><li>A climbing sling is a loop of material usually Nylon cloth tapes. </li></ul><ul><li>Slings are carried by climbers as safety equipment. </li></ul><ul><li>Used as a method to attach themselves to the rock face. </li></ul><ul><li>Also used as a base/anchor for descending (abseiling) down the rock face. </li></ul>
  • 4. Abseil Anchors <ul><li>Anchors are used as a method of securing a rope to allow a descent. </li></ul><ul><li>Preferable anchor sites are trees or spikes of rock. </li></ul><ul><li>A combination of slings and Karabiners are used to provide a sturdy base for abseiling. </li></ul>
  • 5. Abseiling Anchors Cont. <ul><li>Anchors are often sacrificed. </li></ul><ul><li>This means they are left of the rock face open to the elements. </li></ul><ul><li>Reckless climbers may then choose to use this anchor not knowing what state the sling is in. </li></ul>
  • 6. Example of an abseil anchor
  • 7. Nylon Structure <ul><li>Nylon is a form of polyamide. A polyamide is a polymer that contains an amide group -[CO-NH]-as a recurring unit of a chain of hydrocarbons –[CH2]-. </li></ul><ul><li>There are 2 types of repeat units these are AB units or AABB units. </li></ul><ul><li>In type AB nylons the number of hydrocarbons between the amide groups is a constant e.g. Nylon 6 has the form –[NH(CH2)(n-1)CO]- where n=6. </li></ul>
  • 8. Nylon Structure Cont. <ul><li>In type AABB nylons (polyamide n,m) the amount of hydrocarbons between the amide </li></ul><ul><li>Type AABB nylons have the form: –[NH(CH2)nNHCO(CH2)m-2C)]- . Nylon 6,6 is an example of this type of nylon. </li></ul>
  • 9. Weathering <ul><li>Definition :- Weathering causes the disintegration of a material through the action of wind, rain and sunlight. </li></ul><ul><li>Erosion, hydrolysis and ultraviolet light are all constituents of the elements mentioned above. </li></ul><ul><li>These all have an adverse effect on the strength of a sling. </li></ul>
  • 10. Ultraviolet Degradation <ul><li>Nylons are greatly affected by ultraviolet light. This is done through the attack of the repeat units giving rise to the production of free radicals. </li></ul><ul><li>Free radicals are atoms, molecules or ions with unpaired electrons on the outside shell, every atom has a number of electrons within it, these electrons sit within shells in the atom and each shell has a different amount within it. </li></ul>
  • 11. Ultraviolet Degradation Cont. <ul><li>These unpaired electrons are usually highly reactive. These free radicals then react with oxygen in the atmosphere and form carbonyl groups (C=O) in the main polymer chain which in turn weakens the chain. This weakness can be manifested as discolouration </li></ul>
  • 12. Water Infiltration <ul><li>The infiltration of water will affect the strength of the nylon slings by reversing the binding reaction between the repeat units in the nylon chains . </li></ul><ul><li>This un-bonding reduces the molecular weight of the nylon and means that cracks can form in the material with greater ease and are affected by the environment to a greater extent. This infiltration is known as hydrolysis. </li></ul>
  • 13. Measurements To Be Taken <ul><li>The measurements that are going to be taken are: </li></ul><ul><li>Tensile strength </li></ul><ul><li>Hours of daylight </li></ul><ul><li>Amount of rainfall </li></ul><ul><li>Differential Scanning Calorimetry (DSC) </li></ul><ul><li>Fourier transform infra red (FTIR) spectroscopy. </li></ul><ul><li>Optical microscopy of the fracture surface. </li></ul><ul><li>SEM for high resolution images of fracture surface. </li></ul><ul><li>Photographs of the samples </li></ul>To monitor the possible chemical changes in the slings
  • 14. Hypothesis <ul><li>It is believed that the strength of the nylon slings will reduce with increased exposure to environmental degradation. </li></ul><ul><li>It is expected the longer the exposure then the greater the degradation effects. </li></ul>
  • 15. Thanks for listening Any questions?

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