Milk bottle parts

One could estimate the volume of the stock (LxWxH) needed to machine the part from, then divide the specific density by the volume of stock to get weight, then divide by grams per milk jug to get the number of jugs to start saving.

Hmmm. I wonder if a paper shredder would not pelletize milk jugs pretty well.

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Don mentioned in the original post that he tried a paper shredder but it jammed a lot. Probably would need something a little more industrial than a home paper shredder.

OOps. Missed that
Ah, well.

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UPDATE:
So far the simplest manual method seems to be:

  1. Cut the label out of the bottle with a sharp knife
  2. Lay a piece of oven paper on the ovens shallow tray
  3. Put the entire bottle in the toaster oven at 300-350 (tweak temp to prevent browning)
  4. After it melts to clear, keep adding bottles to make a layered slab
  5. Store the slab for later cutting and putting into a mold

[this seems to be easier than cutting the bottle into strips and blender-ing it. I can just keep adding bottles while I am working in the shop.]

To use the slab:

  1. Cut sections from the slab at an appropriate size and put it into the mold for remelting. Pyrex dishes and Teflon bread pans work with an oven paper interface.
  2. Put in toaster oven and heat until clear
  3. Pull from oven and tamp out air with an appropriate sized blunt & smooth thing. I used a 2x4 and oven paper as an interface. (replace this step with vacuum chamber?)
  4. Add more materials (steps 2-3) as needed
  5. Fabricate using the molded plastic in whatever way suits the project.

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I tried some glue!
I got 2 HDPE sections and flash prepared them as @Roberbike suggested.
I then used JB Weld plastic epoxy [Wallmart] to glue them together. This glue showed up when I did a search for TAP Poly-Weld Adhesive on amazon. Not expensive.

Surprise;
It made a really strong joint [qualitative] between two flash-prepared sections of HDPE. I could not cause it to fail by hand.
I also tried two pieces of PVC pipe [I have tried to glue PVC before] and it made a pretty strong joint [qualitative] that I could cause to fail but with a lot of force.

Thanks for the advice now I have a new gluing tool in my arsenal.



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Cool, thanks for sharing :slight_smile:

I am glad you stuck to it!

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Ba-dum-tsk

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Nice and easy process:

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Thanks;
Yes I saw this and if looks good.
I am monitoring the local thrift store for a sandwich oven along with the pressure cooker.

The biggest challenge I have found is chopping the material into small pieces. Lots of bottles and a sore hand from cutting.

I think this would work well for flat moldings but blocks (3x3") still need some other approach.
I have tried an old bread machine with limited success. Perhaps I should hack the bread machine I have and get it to a hotter temp.

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Pressing the molten plastic to a form seems to work:

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I combined the methods described above and I am getting to a point of usable molds.

Now:

  • Cut the label off the bottle with a utility knife
  • Stomp on the bottle
  • Put in the toaster oven on a piece of oven paper @ 300 degrees
  • Pull out when it gets clear
  • With oven gloves peel off the oven paper and force into the mold which is lined with oven paper.
    {this stuff is really HOT and STICKY}
  • Put plunger into the mold and tighten in vice
  • Let cool
  • Take out of vice, Blank drops out

Not pretty but I think it will turn ok!

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