The document discusses plastic recycling techniques. It outlines different types of plastics and their applications. The life cycle of plastic is examined using a water bottle as an example. Key steps in the recycling process are collection, separation, and processing using techniques like manual sorting. Specific techniques for separating plastic mixtures are described, such as using an air table to separate PVC from PVC/PP mixtures. Recycling plastic saves energy and resources compared to producing new plastic from raw materials. The document concludes that recycling is important to reduce environmental impacts and plastic waste in landfills.

1. Plastics Recycling
Sophea Boeut
Georesources Engineering
Mineral Resource Recycling Technology
November, 2015

2. Outline
 Previous Research
I. Introduction
II. Types of Plastic and application
III.Life Cycle of Plastic
IV.Plastic Recycling
- Recycling Process
- Plastic Recycling Technique
V. Conclusion
VI. Reference

3. Previous research of Plastic Processing
• Somsak, S., 2014, Separation of PVC from PET/PVC Mixture using flotation by Calcium
Lignosulfonate Derpressant:
 Separation PVC from mixture of PET/PVC with different ratios of PET and PVC by using CaLS as the
depressant.
• Gjergj, D., et al., 2006, Sorting Techniques for Plastics Recycling:
 Three methods involving in separation ABS, PS and PP from mixture of PVC/PP, ABS/PS and PET/PE. The
three methods used were Air Table for separation PVC from mixed PVC/PP. The second method was
Triboelectric cyclone separator to remove ABS from mixed ABS/PS. The last method was sink-Float and froth
flotation in separation PET from mixture of PET/PE.
• Gjergj, D., et al., 2003, Triboelectrostatic Separation of ABS, PS and PP Plastic Mixture:
 Using Triboelectrostatic to separate ABS, PS and PP plastic from mixture of ABS/PS/PP by applying DC power
to electrode up to ± 20 kV thus to produce electric field of 400kV/m.
• Malcolm, R., et al., Enhanced Plastics Recycling by Cyclone Media Separation:
 The separation focusing on different density of plastics types. The media separators used are Cylindrical and DMS
cyclones as shown in APPENDIX D.
• Plastics-The Fact, 2010, 2011, 2012 and 2013:
 An analysis of European plastics production, demand and recovery.

4. Introduction
• Plastic is the general common term for a wide range of
synthetic or semi-synthetic materials used in a huge, and
growing, range of applications.
• The demand of plastics is increased every year; growth rate is
5-6% every year
• In 2015, the demand will reach 297.5 Mtonnes; and reach until
400 Mtonne in 2020 (GIA, 2014; Paddos, 1999).
• The main production countries: China, Japan, European and
other countries
 What is plastic?
Plastic-The Fact, 2010, 20111,
2012, 2013
Plastic-The Fact, 2013

5. Introduction
Different uses of plastic, (%)
 What is plastic?
Plastic-The Fact, 2013

6. Types of Plastic and Application
• 7 types of Plastics
• SPI have coded each type of plastic by number from 1 until 7
• Every kind of Plastic can be recycled according to their
component and give different recycled products

7. Types of Plastic and Application

8. Types of Plastic and Application
Different type of Plastic with different needs
Plastic-The Fact, 2013

9. Life Cycle of Plastic—Water Bottle
• Water bottle– Mainly made from PET
• The Life Cycle of Water Bottle:
 Raw materials extraction
Manufacturing
Production process
Product distribution and Usage
End-of life
 Reuse (some plastic can be reuse in appropriate of time)
 Recycle
 Landfill
 Energy recovery

10. Life Cycle of Plastic—Water Bottle
Life Cycle of Plastic—Water Bottle

11. Life Cycle of Plastic—Water Bottle
Plastic-The Fact, 2013
In Europe, 2012

12. Plastic Recycling
Categories Number Recycled Product
Easiest 1-PET Fiberfil for coats, sleeping bed
2-HDPE Toys, piping
Less commonly 3-PVC Baby bottle nipples
4-LDPE Wrapping films, grocery, sandwich gabs
5-PP (not so acceptable for recycling)
Useful 6-PS Meat tray, packing peanuts…
Hardest 7-Others Most difficult to recycle
Categories for recycling

13. Plastic Recycling
Recycled Product
PET
PVC
HDPE

14. Recycling Process
• Collection/Sellection
• Separation
• Processing
– Manual Sorting
– Free of contamination
Plastic Recycling

15. Recycling Process
Plastic Recycling
Plastic recycling, 2014
(http://biophysics.sbg.ac.at/waste/plastic.htm)

16. Recycling Process--Video
Plastic Recycling

17. Recycling Process--Extruder:
Plastic Recycling
– The melting equipment of plastic
– Melting system: Shear heating system

18. Recycling Process –Extruder video
Plastic Recycling

19. Recycling Techniques
Plastic Recycling
• The purpose is to separate different kinds of
plastic homogenously from mixture of plastic
and other wastes
• Several techniques applied in recycling plastic:
– Sink-float separation technique,
– Electrostatic separation,
– A dry separation technique that utilizes the
electrical charging of particles

20. Recycling Techniques –case examples
Plastic Recycling
• Separation of ABS,PVC and PP from mixture of
PVC/PP, ABS/PS and PET/PE within 50%/50%
– PVC/PP => Air Table
– ABS/PS => Triboelectric cyclone separator
– PET/PE => Combination of Sink-Float Separation
and Froth Flotation

21. Recycling Techniques – ABS, PS, PP separation process
Plastic Recycling

22. Recycling Techniques – ABS, PS, PP separation process
Plastic Recycling
Air Table:
- Density of PVC = 1.4 g/ml; and PP
= 0.9 g/ml
- Velocity of airflow: 1.6m/s
-Frequency of deck: 11.95/s
-End slope α=4.4°; side slope β=2.5°
-Sample size:2.38– 3.36 mm
 PVC, high density => settle on
the bed
 PP, low density => Float on
the top of the bed

23. Recycling Techniques – ABS, PS, PP separation process
Plastic Recycling
Triboelectric cyclone separator
• Separate ABS from ABS/PS
• DC power supply
• Based on the different charge of Plastic types
• ABS goes to negative part, PS goes to Positive Part

24. Recycling Techniques – ABS, PS, PP separation process
Plastic Recycling
Triboelectric cyclone separator

25. Recycling Techniques – ABS, PS, PP separation process
Plastic Recycling
Sink-float and flotation:
-PET’s density = 1.35 g/ml,
PE’s density = 0.96 g/ml,
lower than water’s.
-Reagent Dodecylamine
(DAA) = 0.02 kg/m3, for PE
to float out and Pet is sink as
hydrophilic stage.
-Sample size: from 2.38– 3.36
mm, is the size after shredders

26. Recycling Techniques – ABS, PS, PP separation Result
Plastic Recycling
Types PVC from
PVC/PP
ABS from ABS/PS PET from
PET/PE
Method Air Table Triboelectric cyclone
separator
Sink-float and
Flotation
Recovery 97.1% PP;
99.5% PVC
100%PS;
74% ABS
90.3% PET
Grade 99.3% PP;
99.3% PVC
---- 99.7% PET
Result:

27. Recycling Techniques – Separation of PVC from PET/PVC
Plastic Recycling
Method use: Flotation
• Three mixture of samples are experimented
• Ratio PET/PVC: 75:25, 50:50, 25:75
• Depressant CaLS = 7.5 mg/l
• pH ; 11-12
• Time : 20 mn
• Pipe oil : Frother agent, 10 drops
• Size shape: 5x5 mm and thickness 0.3 mm.
• Temperature = 60°C

28. Recycling Techniques – Separation of PVC from PET/PVC
Plastic Recycling
Process of experiment:
- PET : sink
- PVC : Float
Somsak, 2014

29. Recycling Techniques – Separation of PVC from PET/PVC
Plastic Recycling
• Result
Ratio of
PET/PVC
%weight
PET
CaLS
(mg/l)
Recovery
PVC PET
75:25 74 7.5 100 100 (after 4th
of Rougher)
50:50 48 7.5 100 100 (after 2th
of Rougher)
25:75 24 7.5 100 100.(after 3th
of Rougher)

30. Saving term-- Do you Know…?
Plastic Recycling
Recycling plastic is making the balance of environmental,
energy, and economic saving.
 4% of natural oil, which is estimated about 2 million
barrels of oil every day used to produce Plastic every year
(The ImpEE, 2005; Recycling Fact, 2012)
Recycle Plastics need only 10% of total energy compared
to production of plastic from virgin sources (Recycling Fact,
2012)

31. Saving term-- Do you Know…?
Plastic Recycling
Comparison the energy use and resources price of virgin
and recycled materials
Commodity
plastic
Energy, virgin
materials (MJ/kg)
Price, virgin
materials ($/kg)
Energy, recycled
materials (MJ/kg)
Price, recycled
materials ($/kg)
HDPE 77-85 1.9-2.0 ≈35-45 0.84-0.97
PP 75-83 1.8-1.85 ≈35-45 0.99-1.1
PET 79-88 2.0-2.1 ≈60-64 1.1-1.2
PS 96-105 1.5-1.6 ≈40-50 0.75-0.86
PVC 63-70 1.4-1.5 ≈35-40 0.77-0.99
(The ImpEE, 2005; Recycling Fact, 2012)

32. Conclusion
 Plastic is widely used all around the world for everyday life,
construction, automobile, electronic and other things to make
life more modernity and convention, but in the same time, it
cause environmental problem such as global greenhouse gases
emission (methane gas).
 Recycling Plastic is not only saving the petrochemical
sources, but also saving the energy.
 Some recycling technique such as air separation, density,
electrical, sink-float and flotation are suitable with acceptable
efficient of recovery, according to the previous researches.

33. Conclusion
Plastics are too valuable to through away!
Each piece of plastics waste is money!
Landfill plastic must be eliminated since it takes
hundreds of years to discompose and causes
contamination to the surrounding communities.
Please, think a little bit that…

34. Conclusion
Please, think a little bit that…
http://www.co2g.co.uk/?page_id=149

35. References
[1] Somsak, S., 2014, Separation of PVC from PET/PVC Mixture using flotation by Calcium
Lignosulfonate Depressant, Chulalongkorn University, Bankok, Thailand
[2] Gjergj, D., et al., 2003, Triboelectrostatic Separation of ABS, PS and PP Plastic Mixture,
University of Oviedo, Oviedo, Spain
[3] Gjergj, D., et al., 2006, Sorting Techniques for Plastics Recycling, , University of Oviedo,
Oviedo, Spain
[3] Malcolm, R., et al., Enhanced Plastics Recycling by Cyclone Media Separation,
University of Oviedo, Oviedo, Spain
[4] Plastic-The Fact, 2010, 2011, 2012, 2013, An analysis of European latest plastics
production, demand and waste data
[5] Plastic recycling, 2014, (online), (www.biophysics.sbg.ac.at/waste/plastic)
[6] The ImpEE Project, 2005, Recycling of Plastic, University of Cambridge.
[7]Plastic Waste Management Institute, 2009, An Introduction to Plastic Recycling.
[8] http://www.co2g.co.uk/?page_id=149

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