• Hi Javier — Thanks for the link! I haven’t found this machine before. It appears more powerful than the other three — 600W. The fact that it’s in the UK also makes a big difference. I would certainly consider renting it for a period of time, to test different moulds. If it’s promising, and my parts take on, I would buy it (would save a lot of…[Read more]

  • Thanks, Brad! I was able to figure out from LNS that the machine has two shots, i.e. the second shot would be faster than 3-5 minutes. Since my parts are very small (about 100 mg each), I could design the mould to make an array of 50 parts at once (5-10 grams), so the throughput should be no problem. For example, it takes me 5 hrs to machine the…[Read more]

  • I am looking for a injection moulding method to make very small (3-5 mm) parts out of polypropylene. Not mass production, I would be happy with one part per min. I can make small moulds of any material (even glass) as I have a tiny precision mill. Tried to mould the ghetto way in the oven, but the plastic oxidizes and crumbles, and as my moulds…[Read more]

  • I am looking for a injection moulding method to make very small (think M4 screw size) parts out of polypropylene. Not mass production, I would be happy with one part per min. I can make small moulds of any material (I have a tiny precision mill). Companies want 50K+, forget it, so I looked whether they make small manual machines.

    First, I found…[Read more]

  • I would imagine controlling the temperature would be difficult. I tried melting PP on a stove in a flask, and it crumbles and falls apart upon solidification. Once I strated controlling the temperature it was better.

    Since you have gas I would use a generator to power the moulding machine

  • Following up with the results. To avoid crumbling I controlled the temperature better.

    Pre-heated an oven to 165 degs. It’s a biotech grade one, not fancy, but not a cooking oven, either.
    Placed an Alu tray into the oven
    Placed aa flat, clean soda lime glass plate onto the metal plate, about 200×100 mm x 1 mm
    Placed 5 grams of PP tubes on the…[Read more]

  • Thanks, Jegor! I will give this a shot: will adjust the temperature and, may be, will even blow N2 over it. The oxidation is bad news for my purposes not just because of crumbling, but because I need the PP to remain hydrophobic.

    Is it still OK that PP entirely liquifies? It is much easier to get the shape I want when it flows, as I need it to…[Read more]

  • Hi folks,

    I am new to plastic re-melting. I am trying to mould flat sheets from “virgin” polypropylene recycled from biomedical tubes. So, I tried melting some tubes (say, 20 grams worth) in a flask until they liquified (there was even some boiling), and then poured a few tablespoons worth of the liquid into a hot plate preheated to 200 degs, let…[Read more]