Environmental Properties of Plastics

Environmental Properties of Plastics

#1 – Polyethylene terephthalate (PET)

Creation: Production of 1 kg of PET requires the equivalent of about 2 kg of oil (raw material and energy).

Disposal: Incineration in an incineration plant mainly produces water and carbon dioxide. Heating value is equivalent to 1/2 kg of oil. PET can be recycled into fibres that are used for polyester fabrics. 

The main virtue of PET is that it is fully recyclable. Unlike other plastics, its polymer chains can be recovered for additional use.

#2 – High Density Polyethylene (HDPE)

Creation: It takes 1.75 kilograms of petroleum (in terms of energy and raw materials) to make one kilogram of HDPE.

Disposal: Used PE plastic can be recycled through remelting although there is a quality loss. Incineration is straightforward and comparable to oil, since PE only consists of hydrogen and carbon atoms.

In an incineration plant only water and carbon dioxide are produced. However common additives like UV-stabilizators (e.g. carbon black), dyeing agents and fire protectors can produce other waste products. Heating value is equivalent to 3/4 kg of oil.

#3 – Vinyl (Polyvinyl Chloride or PVC)

Creation: Production of 1 kg of PVC requires the equivalent of about 1 1/2 kg of oil (raw material and energy).

Disposal: When PVC burns, strong hydrochloric acid emanates. Incomplete combustion can develop poisonous dioxine. PVC can be recycled and used in e.g. garden hoses. Heating value is equivalent to 1/4 kg of oil.

PVC is not typically recycled due to the prohibitive cost of regrinding and recompounding the resin compared to the cost of virgin (unrecycled) resin. There is also some contention as to whether PVC is recyclable at all. Greenpeace states that there is no method to recycle vinyl..

#4 – Low Density Polyethylene (LDPE)

Creation: LDPE is a thermoplastic made from oil. Production of 1 kg of LDPE requires the equivalent of about 2 kg of oil (raw material and energy).

Disposal: Same as HDPE, see above.

#5 – Polypropylene (PP)

Creation: Production of 1 kg of PP requires the equivalent of about 1 3/4 kg of oil (raw material and energy).

Disposal: Incineration is straightforward and comparable to oil, since PP only consists of hydrogen and carbon atoms. In an incineration plant only water and carbon dioxide are produced. Heating value is equivalent to 3/4 kg of oil.

#6 – Polystyrene (PS)

Creation: Polystyrene is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum. Production of 1 kg of PS requires the equivalent of about 2 1/4 kg of oil (raw material and energy). Styrene monomers are harmful to health.

Disposal: Incineration in an incineration plant mainly produces water and carbon dioxide. Heating value is equivalent to 1 kg of oil.

The majority of polystyrene products are currently not recycled due to a lack of suitable recycling facilities. Furthermore, when it is "recycled," it is not a closed loop — polystyrene cups and other packaging materials are usually recycled into fillers in other plastics, or other items that cannot themselves be recycled and are thrown away.

Where is it recycled?

Sources:

Greater Vancouver Regional District “Just the Facts- Plastics” http://www.gvrd.bc.ca/recycling-and-garbage/pdfs/facts-plastics.pdf

Environment and Plastics Industry Council (EPIC) website:  http://www.cpia.ca/epic/?lang=EN

Wikipedia website: http://en.wikipedia.org/wiki/Main_Page

Design inSite – Designer’s Guide to Manufacturing website: http://designinsite.dk/