Reclaiming Polyethylene Pipe

[strantor]

I'm glad to see there is more interest in plastics. I have been wanting to give it a try ever since running across the "precious plastics" videos on youtube but just haven't had time. I'm curious to see what direction you guys go with this stuff.

 

[ericc]

Here is a jack puck. It is used to cradle the seam of the frame on modern cars without flat jacking points. Also shown is the temporary one made out of wood. Wood breaks, as it is easy to see. Note that I was entirely prepared for the eventual break and there was nothing under the car to be crushed when it settled suddenly.

 

[MrWhoopee]

I have been experimenting with various plastics in a deep fat fryer. I have tried polypropylene ans PET with promising results. I changed the thermostat to cycle at a slightly higher temperature. As manufactured, it would reach 400ºF and I raised the setting to around 500ºF. The big problem I have now is radiant heat loss so my next step is to insulate the wall of the fryer.

I'm back out in the shop, using the toaster oven, and experiencing the same problem. With the thermostat set at 400º F the poly is about the consistency of refrigerated honey. Got my first slab out. Not pretty, but still encouraging. Looks like a pan of burnt brownies.

 

[strantor]

I'm back out in the shop, using the toaster oven, and experiencing the same problem. With the thermostat set at 400º F the poly is about the consistency of refrigerated honey. Got my first slab out. Not pretty, but still encouraging. Looks like a pan of burnt brownies.

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If it were mine I'd call it a success. I would like to see those holes filled in but something functional can surely be made from that.

Did you knead it or is that straight out of the oven?

 

[MrWhoopee]

If it were mine I'd call it a success. I would like to see those holes filled in but something functional can surely be made from that.

Did you knead it or is that straight out of the oven?

I kneaded, pressed, clamped, etc.

It's a very solid piece, most of it a little over 1/2" thick. I need more heat and a better release agent.

 

[RJSakowski]

One thing that I noticed is that there is a fairly large difference between the melt point and the free flow temperature.

The experiment that I did with PET was encouraging, The slug I ended up with was free from air bubbles and seemed to have fairly good mechanical properties. I need to repeat with a higher temperature and larger sample.

There must be a point at which the plastic is free flowing as injection molders start with pellets so there will be a lot of initial air inclusion.

 

[woodchucker]

I have over 100' of 1-1/4" 125 psi black poly-pipe that came out of the (dry) well that I pulled. I could cut it into 3.5' lengths and put it in the recycle bin, but, due to the pandemic, the garbage service is not processing recyclables, they are just going into the landfill. I also hate wasting something that is potentially useful. I've decided to try cutting it up and melting it into slabs for future use. PE has a melting point around 250° F, so I did a test melt in my shop toaster oven. It worked, but the plastic did not melt uniformly or completely. Portions of it liquified, but the skin of the pipe remained semi-solid. It did seem to form a solid, if not homogenous, piece once cooled. I've seen videos of people doing this with milk jugs, etc., but I wasn't really impressed with the results. Has anyone tried this?

@RJSakowski showed a block that he created to make a drill bit or end mill holder. He got me interested, because I like the idea of working with plastics that are recyclable like this.

 

[woodchucker]

I'm back out in the shop, using the toaster oven, and experiencing the same problem. With the thermostat set at 400º F the poly is about the consistency of refrigerated honey. Got my first slab out. Not pretty, but still encouraging. Looks like a pan of burnt brownies.

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It really does look like brownies. Can you send that my way.

I would say that's a success. That's a very usable block.
That'll machine well I think.

 

[Larry$]

I'd like to see more about melting plastic into something usable. My trials were less than fully successful.

 

[Bi11Hudson]

melting plastic into something usable

As a rule, I avoid plastic but do use it. Even for my model trains. . . The one point I will concede is that it's a good electrical insulator, especially at low voltage of 600 volts or less. Otherwise, plastic is like metal for making useful parts. It can be machined, the point of this site. And it can be cast, usually in an injection mold. It is nowhere as strong as metal but for making small parts like knobs and handles it is as, or more, useful than metal. And best of all, once the details are worked out, it's cheaper.

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