Advice on PETE recycling. Molds, injection and such.

[indierecycler]

So. Here's my situation. I manage multiple car washes and wind up dealing with a lot of garbage. I usually wind up removing all the plastic containers I can and finding A way to make sure they make it into the recycling bin. But Ive been thinking lately that instead of putting off all my pop bottles onto other companies to recycle, why not do it myself ? its not rocket science is it ? I'm willing to put the time and money into making this happen. I have a few books on plastic on the way. In the mean time I have been investigating plastic molds and injection machines and such. It's been really hard to gather information on the types of plastic and chemicals that I could use to send through the injection machines. I would even be willing to pay someone if they could help me out on this. Ideally I see myself poping those shredded up coke bottles into my tabletop injection machine and molding up some planter pots or clothes hangers. Small Stuff possibly sold at local gardening stores. Rake heads and stuff like that. So my question is, when recycling basic plastics like the #1 PETE... can this be done without a barrage of different machines and chemicals/ additives ? (willing to drop some good money on equipment). Can anyone provide ANY info or links ???? please set me in the right direction !!! I'm trying hard to find this info but struggling. Any help at all will be greatly appreciated.

Thanks,
Indie

 

[MikeHalloran]

Thermoplastics have been recycled since they existed, primarily by shredding/ grinding/ melting product that was defective coming out of the molding machine.

Post-consumer recycling adds variability to the recycled stock, because you don't have 100 pct control of what goes into the mix.

In all cases, the mechanical properties of recycled materials are inferior to those of new ones, and more variable, so they tend to end up in different sorts of products.

Big wins for recycled material of which I am aware include carpet fibers and insulating fiber/batt for garments, both of which involve fully melting the material and extruding it into fiber.

There is some traffic in 'plastic lumber' made of recycled material. There is some brownish stuff in lumberyards that appears to have been shredded to powder and not quite melted in some kind of extrusion press, not an injection molding press. The stuff is not unattractive, but it's oddly 'limp' relative to wood. It's sold for use as decking, with extra support underneath because it doesn't span gaps like wood.

I have also seen some very much coarser 'plastic lumber' apparently made of random crap plastic, coarsely shredded and partially remelted, apparently in some sort of low pressure box tool. The product is extraordinarly ugly because of inclusion of bright garish colors, and rather weak because shredding to 1cm or so retains shapes and cavities already molded into the constituent feedstock, and may be limited to certain municipal projects in SoFla where the producer was related to a particular politician who demanded that said particular product be used despite protestations.

Injection molding machines and tools are sensitive to inclusions and chemical properties of what you put in them, so may require extra maintenance in making recycled products. The problem is exacerbated because recycled goods don't usually sell for premium prices. In particular, flowerpots are already pretty cheap, so there may not be much money for you there.

But you are on the right track, in the sense that you need to come up with a salable product you can make from the feedstock you get for free. Injection molding machinery may not be necessary for that transformation. Some kind of shredding and some kind of heat probably will be required.

There just has to be at least one trade magazine for plastic recycling, but I haven't run across it yet.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

To use the American expression, pop bottles are PET.

PET is a right bitch to mould and even most skiled experienced moulders have problems with it.

First off it is super sensitive to moisture in the plastic during moulding and must be carefully dried with exceptionally good dryers.

Regards
Pat
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[Pud]

It will probably be a blow-moulding grade which will be difficult to mould as it will be very high viscosity.

That's apart from the other considerations as Pat has mentioned a few of. It also only needs about 3-4 hrs exposed to ambient conditions and it will require drying again.

It is indeed, "a bitch to mold".

h

http://www.tynevalleyplastics.co.uk