RECYCLING AND MATERIAL SELECTION OF POLYMERS, METALS.pptx

A product that is manufactured from the material, and the product is put into useful service.
Eventually the product wears out or is made obsolete because a better product comes on the market.
At this stage our tendency has been to junk the product and dispose of it in some way, like a landfill, that eventually returns the material to the earth.

1. RECYCLING AND MATERIAL SELECTION BY MANIKANDAN S 2021110007

2. Can you guess what I mean?

3. When and why we go for recycling? A product that is manufactured from the material, and the product is put into useful service. Eventually the product wears out or is made obsolete because a better product comes on the market. At this stage our tendency has been to junk the product and dispose of it in some way, like a landfill , that eventually returns the material to the earth.

4. What is recycling and material selection?

5. automotive fuel tank , the following factors are most important: manufacturability/cost/weight/corrosion resistance/permeability resistance/ recyclability. Select the suitable material ! STEEL: Terne -coated steel Electrocoated zn-ni steel PLASTICS HDPE (high-density polyethylene) M ulti layer HDPE

6. Case study: In 1990s Tests have shown that Neither painted nor bare terne -coated steel ( traditional ) will resist the corrosive effects of alcohol for the 10-year expected life of the fuel tank. In addition, the EPA has introduced fuel-permeation standards that challenge the designs and materials used in automotive fuel tanks. Two new competing materials have emerged to replace terne steel: 1) electrocoated zinc-nickel steel sheet and 2) high-density polyethylene (HDPE). The steel sheet is painted on both sides with an aluminum-rich epoxy . The epoxy is needed to provide exterior protection from road-induced corrosion . But nearly five times of the cost .

7. . HDPE is readily formed by blow-molding into the necessary shape, and if has long-term structural stability, but it will not meet the permeability requirement. Two approaches have been used to overcome this problem: 1) the first is multilayer technology , in which an inner layer of HDPE is adhesively joined to a barrier layer of polyamide 2) the second approach is a barrier to permeability that involves treating the HDPE with fluorine .

8. Analyzing of maetrials Terne -coated steel (8 percent tin-lead coating ) Advantages: low cost at high volumes, modest material cost, meets permeability requirement Disadvantages : shape flexibility, poor corrosion protection from alcohol fuels, lead-containing coating gives problems with recycling or disposal electrocoated zn-ni steel Advantages: low cost at high volumes , effective corrosion protection, material cost, meets permeability requirement , r ecyclable Disadvantages : weldability , shape flexibility Stainless steel Advantag es: high corrosion resistance, recyclable , meets permeability requirements Disadvantages : cost at all volumes, formability, weldability

9. Material selection Plastics HDPE (high-density polyethylene ) Advantages : shape flexibility, low tooling costs at low volumes, weight, corrosion resistance Disadvantages : high tooling costs at high volumes, high material cost, does not meet permeability and recyclability requirements

10. Material selection Multilayer and barrier HDPE Advantages: same as HDPE plus meets permeability requirement Disadvantages: higher tooling costs at high volume, higher material cost, hard to recycle

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12. References Open-loop recycling: A LCA case study of PET bottle-to- fibre recycling https:// doi.org/10.1016/j.resconrec.2010.06.014 Use of recycled waste pet bottles fibers for the reinforcement of concrete https:// doi.org/10.1016/j.compstruct.2012.09.019 You tube: https:// youtu.be/H7GF2UV30Zs?si=VTvIgX5r2g0LXRAt