Aim: to examine a number of plastics raw materials, plastics artefacts and related materials to determine:
a) Write down the name of the plastic resin used.
b) Write down the name of the artifact(s)
c) Observe and record the range of forms
d) Use the notes provided to determine the processing method used to manufacture the item. Make sure that you work systematically.
Note: you could be evaluated on your understanding of this work.
Aim: To become familiar with the properties demonstrated by some plastic materials and to have some hands on experiences with plastics.
Procedure: Students rotate around in station in order - spending a defined time at each station. The students stay at each station until they have completed the exercise and then all students move on the teacher’s instruction in a clockwise or anti-clockwise direction.
Safety note: When plastics are subjected to extreme treatments such as burning or strong heat irritating gases may be emitted. It is essential that these exercises are carried out in a well ventilated room. Exercises such as cutting polystyrene with a hot wire or expanding unexpanded polystyrene beads should be carried out in a fume cupboard — or next to an open window.
Introduction: Over the last 35 years there has been a progressive replacement of metal parts by plastic ones in motor cars to decrease the weight of cars. This reduction in weight results in significant fuel savings as less energy is needed to move a lighter vehicle. Experts estimate that there are approximately 1,000 plastics parts of all sizes in the average car - or about 110kg of plastics (APME,99).
Average amounts of plastics in cars is shown in the data below.
|1960 - each car contained||10 kgs of plastic.|
* source: Society of Plastics Engineers.
This exercise is designed to develop team work skills, decision making skills, observation skills and technological skills. Keys are common in many different fields of Technology. Above all this exercise is designed to encourage you to become more familiar with a range of plastic materials).
Health & Safety - Note carefully
You will be presented with a number of common plastic items. As well you will need
Work methodically through the key for each plastic in groups of 2 or 3.
|1. Touch it with a red hot nail. Does it melt?||
yes .... go to 2
no.... go to 3
|2. It is a thermoplastic. Does it float on water?||
yes . . . . go to 4
no.... go to 5
|3. It is a thermoset - which one? Heat over a burner - Remove and smell carefully.||
Does it smell fishy? yes.... go to 6
Does it smell carbolic? (sharp chemical smell) . . . . go to 7
|4. Is it a foam plastic? (ie can you see holes or air pockets in it?||
yes....go to 8
no.... go to 9
|5. Try to ignite a small sample over a spirit burner. Does it burn?||
yes .... go to 10
no.... go to ll
|6. Is it white or light coloured?||
yes ... . urea formaldehyde or Carbamide Methanol
no . . . . recheck earlier steps
|7. Is it dark in colour (Black or dark brown)?||
yes . . . . phenol formaldehyde/phenol methanol) *
no . . . . recheck earlier
|8. Burn a small piece in a spirit burner? Does it burn?||
a) with a yellow flame and an acrid (pungent or unpleasant smell . . . . polyurethane foam
b) with black smuts . . . . expanded polystyrene
|9. Can you scratch it with your fingernail?||
yes .... go to 12
no . . . . polypropylene
|10. Does it produce a yellow smokey flame?||
yes . . . . PET (Polyethylene terephthalate)
no.... go to l0a
|lOa. Does it drip?||
yes .... go to 13
no.... go to l4
|11. Teflon - unusual in domestic situations except on saucepans.|
|12. Is it easy to scratch with your fingernail?||
yes . . . . (easy) LDPE (Low density polyethylene)
no . . . . (difficult) HDPE (High density polyethylene)
|13. Is it self extinguishing?||
yes .... go to 15
no.... go to l6
|14. Is it self extinguishing?||
yes .... go to 17
no.... go to l8
|15. Carefully smell the burning material. Does it smell:||
a) Like burning hair . . . . Nylon
b) With an acrid smell - flexible PVC (Check by cutting a piece it easy to cut - if so it is flexible PVC)
|16. Does it produce smuts while burning||
yes .... Polystyrene (unexpanded)
no.... go to l9
|17. Examine the appearance.||
Is the material transparent? Polycarbonate.
Is the material coloured? ... . Rigid PVC (Poly Vinyl Chloride)
|18. One of the less common plastics - Not identified.|
|19. Blow out the plastic and smell carefully. Does the plastic smell fruity?||
yes .... go to 20
no .... go to 2l
|20. Is the material transparent?||
yes .... Acrylic
no . ...
|21. One of the less common plastics - not identified|
Reference: ICI Chemicals