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[Rich griff]

I like yoghurt.


The yoghurt comes in white plastic tubs, pe I think ?


Any chemists on here ?


Is there a low cost safe solvent that can disolve cut up yoghurt pots to make a liquid that is pourable so this reclaimed plastic liquid can be cast please ?


Low cost, available solvent that will not kill me or cause a health hazards please ?


I propose making a casting box mould with inner and outer so the plastic solution can be poured in and left to go off. A release agent could be a sprayed on moulds, wax perhaps ?


All help greatly appreciated.


Failing a pour in mould, use the plastic solution to make largish sheets.....

[ballastanksian]

In a word no. There are several solvents that would do the job of dissolving the plastic but nothing I know of that won't mess with your health. Dichloromethane is at least non flammable, but still not good for you in the amounts you would require to create a liquid plastic. 
To be fair, the most reliable method to recycle plastic is ground down and melted using heat and pressure.



You could do it if you had a form of extraction to remove fumes, perhaps if you made your own fume cupboard like those used in laboratories? I would worry though about differential evaporation and shrinkage. You would need some serious experimentation to get reliable results. I think the best bet is to go down the route of resin, though I salute your efforts to recycle materials.

[Rich griff]

Thanks for the reply Ian.


I have played with cutting up the pots into small pieces and soaked/submerged in normal petrol to end up with a soft disc in the jam jar bottom.
Removed disc and allowed to "dry out" but the plastic is a bit brittle.


So, no safe "wonder chemical"...


May/will probable go down glass fibre route or even carbon fibre.


I will do some experiments with the mould, sealing the surface for a good finish, release agent and gelcoat outer skin of the hull.


May be able to make inner and outer for heating plasticard, or vac forming...


More to do........

[Circlip]

And I was once criticised for re-using recovered Balsa - - -


 Any solvent is injurious to health if inhaled in sufficient quantities. Probably OK if upwind in a well ventilated Garden. 


  Regards  Ian.

[warspite]

There was / is a company in Dundee we supplied fans to in the 'old' days, that made yogurt / rice pots and recycled the remnants, the material was formed into a sheet of plastic a certain thickness as a very big roll - like newsprint width but thicker, this went through the machine and was pressed into the pot shape using heat and pressure, it then moved on a section and the pots 'punched' out, the sheet then rolled up and then sent for granulating into new plastic pellet to be made into a fresh sheet, its that long ago I even think it was sent downstairs and granulated there, but would have to research that.


Another company we sold fans and systems too, also recycled there waste plastic, HDPE, they made Milk bottles for Wiseman dairies in Trafford Park, they could only use about 10% regrind in the making of new bottles, you had the tops, bottoms and the odd actual bottle that were being sent to be granulated, down ducting and dedusted at the same time, their bottle making machine was an injector on a massive vertical carousel, and they had at least 6 to 8 of them.


Again other companies recycling plastic waste bottle (Liverpool and Leicestershire) both granulated and melted HDPE into either black piping for sewage drainage or clean beads for making into fresh plastic.


So all those companies melted down the plastic, only several thousand pounds of equipment can achieve, some day they will develop nanobots that will recycle more effectively, but not in my lifetime.

[Rich griff]

What about acetone ?


Nasty stuff I know but....

[Circlip]

Had arguments with the Hi-Viz warriors at the local 'Re-cycling' centre about non recyclable material. DOES IT MELT WHEN YOU APPLY HEAT. Problem is, only same composition plastic is suitable for regran and added to virgin material to make same product - HDPE don't mix with PP or PTFE etc.


  Ultimately, it don't matter a Monkeys left spheroid if it's exported and dumped in the countryside of so called 'Third World' countries. The will to recycle is tempered by cost implications.


 To find the most effective solvent for a give plastic, consult Suppliers lists BUT, not all plastics succumb to solvents.


  Regards  Ian.