What are plastic and how are they classified?

Answer 1

a. Visually examine the sample, looking for recycle codes

b. Try assessing the flexibility by bending, and look at the bending zone

- does the material stretch or is it brittle?

c. Test the hardness, try scratching it with pencils of differing hardness

( B,HB,1-6H ) to ascertain which causes a scratch in the plastic.

Alternatively, attempt to scuff the sample with a fingernail.

d. Cut a small slither with a sharp knife. Does the sample cut cleanly

( thermoplastic )?, or does it crumble ( thermosetting )?

e. Hold sample in small flame, note whether it burns, self-extinguishes on

removal from the flame, colour of the flame, and smell/acrid nature of

fumes when flame is blown out ( Caution - the fumes are likely to be

toxic ). Also attempt to press melted sample against a cold surface, and

pull away - does sample easily form long threads.

f. Drop onto a hard surface, does the sample "ring" or "thud"?

g. Place it in water. Does it float, sink slowly, or sink rapidly?

If it sinks rapidly, it is likely to be halogenated ( PVC, Viton, PTFE )

If it sinks slowly, possibly nylon

If it floats possibly polyethylene or polypropylene.

Answer 2

Plastics are classified according to the numbers 1 though 7. Number 1 is polyethylene or PET. Number 2 is high density polyethylene, or HDPE. Number 3 is PVC. Number 4 is low density polypropylene. Number 5 is polypropylene. Number 6 polystyrene.

Answer 3

Plastics are commonly classified by their physical properties. These include their compressibility, their reaction to chemicals, and their overall strength.

Answer 4

plastic plastic and margerine, a butter substitute that is one molecule away from plastic plastic. pretty gross, huh?

Answer 5

Two classes of plastics exist: thermoplastics and thermosettings.

Answer 6

there arent any

Answer 7

Materials