Milk Cartons: Plastic or Cardboard

Drax

Just a quick question - If I am in a supermarket and I have the choice buying milk in a plastic bottle or a tetra-pak container, which one is better for recycling? Or does it make any difference? I would imagine the tetra-pak would be at least biodegradable?

SeanW

bit of a difficult issue - tetra paks do have some plastic or synthetic components on the inner lining of the carton. So they aren't fully biodegradeable AFAIK.

My local recycling facility has a big skip for all kinds of plastic bottles, so while I might be tempted to go for the "cardboard" milk carton normally, I usually prefer the plastic ones on the basis that these can be recycled much more effectively, at least around here.

Macha

Tetrapak can be fully recycled, as can plastic so no difference between them there.
So the other issues are:
a) embodied energy (e.e) in each material (no idea)
b) energy needed to recycle (plastic better, according to bedlam)
c) renewability of material. (Tetrapak made mainly of paper so better)

So far pretty much even, but if you look at the Tetrapak website, they seem very committed to environmental issues so I'd go with them:
http://markets.tetrapak.com/environmentalperformance/content/frset_main.asp?navid=146

Danno

The taste of the milk out of them plastic "gallon" drums is disgusting. Milk always has a hint of sour taste from it. Proper tasting milk comes from the tetra pak.

Alun

taconnol wrote: »

So far pretty much even, but if you look at the Tetrapak website, they seem very committed to environmental issues so I'd go with them:
http://markets.tetrapak.com/environmentalperformance/content/frset_main.asp?navid=146

Many years ago (back in the late 80's) I worked for a short while at one of the Tetrapak plants in Germany, and even back then they were heavily into this.

One solution they were looking into then which looked promising was to finely chop up the used cartons, add some colouring, and some liquid (don't know what) and press the resultant thick gloopy mess under very high pressure and temperature into a thick board which would be used for kitchen worktops. They showed me some samples of what they'd made and it was both quite light but at the same time very, very rigid. It was also supposed to have great machining properties, and didn't look half bad either.

It works because there is quite a high plastic content in the material used for the cartons, and it's this that when pressed at high temperatures that fuses and hold everything together. The ones used for fruit juices also have a foil layer in them to stop any light getting in, but I'm not sure whether they could use them as well.

Basically it was a less complicated procedure than pulping the stuff and separating out the plastic and metal components. Don't know if it ever took off though.

blackbox

I use either for lighting the fire - better to re-use than recycle!

If using the plastic bottles, be sure to remove the caps - an elderly neighbour burnt his house down when a plastic bottle popped out of an open fire and set his armchair on fire.

NB I agree with Danno that milk tastes better out of tetra pack. This is because it keeps out the light.

BendiBus

blackbox wrote: »

I use either for lighting the fire - better to re-use than recycle!

Burning plastic in an open fire sounds a bit toxic to me.

blackbox

bedlam wrote: »

Recycling would be better than subjecting your self to possible toxic fumes and Dioxins from burning plastic.
Also neither are going to disappear, after burning you are still going to have to dispose of the remains which are now mixed with what ever the fire was made from so separating is going to be harder.

I think you will find that plastic milk cartons are made from LDPE (low density polyethylene). This is a hydrocarbon that burns as cleanly as oil. It does not produce dioxins as there is no chlorine present (unlike PVC, which should never be burned except in a proper incinerator, but much better to recycle it). I would expect that LDPE burns at least as cleanly as commercially available firelighters.

Regarding the ash, being a pure hydrocarbon it produces very little - have a look at how little ash there is in an central heating oil burner after burning 1000 litres of oil.

The simplistic designation of all plastics being the same is something that we in Ireland have yet to overcome. I cannot understand how my local recycling centre (Wicklow) asks for five different types of plastics to be put in one container, especially after the manufacturers have gone to the trouble of putting a number on each item. The materials would be much more valuable if segregated.

Oh, and Bendibus, I wouldn't use an open fire for heating - they waste way too much fuel because of their low efficiency - woodburning stoves all the way.