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melting plastic?

I want to melt old plastic objects like boxes bottles cans etc. and make plastic plates (thin like 1/6") of them. how can I do this at home and how to prevent plastic from burning while melting? also what to do if I want to add color to it?

Update:

thanks for helpfull information but i was looking for a simple way without such things as molds, jacks injection etc. tought i need to melt them in a metal can and pour melted plastic in a seccond metalic sink (like a cake mold). and what will i get this way?

9 Answers

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  • 1 decade ago
    Favorite Answer

    Unless you know what your doing, what types of plastic to use (and there melting points), How to mold them & know how dangerous it could be to do this (melting plastic doesn't come off skin very easily) I wouldn't go any further. The money and time you spend won't give you the finished product you seek. Sorry.

  • 1 decade ago

    Well, that is going to depend mainly on the type of plastic you use. Each type of plastic has a different melting point. Part of the way to tell what plastic you have is by looking at the recycle symbol you have on the plastic.

    1 = PETE or polyethylene terepthelate

    2 = HDPE or high density polyethylene

    5 = PP or polypropylene

    I'd recommend sticking to these 3 types of plastics. The are considered thermoformed plastics and can be remelted down and re-used. The important thing you want to note is what temperature each of these plastics melts at. You want to get the temperature to the melting range, but not too hot. If you get it too hot then you will burn the plastic. Normally, a steel mold will be made and the melted plastic will be injected into the mold. This requires hydraulics to inject the plastic into the mold. The plastic will shrink after it cools. The amount of shrinkage depends on the plastic type. You could create a home shop to do this by creating a bottom mold and a top mold then pouring the melted plastic into the bottom mold and using a hydraulic jack to compress the two molds together. Then you will need an overflow vent on mold to allow the excess to be squeezed out. You may want a pressure gauge so that you don't put too much pressure on the mold.

    I'd recommend sticking to the same type of containers for reuse. Even though the plastics may be the same plastic type the temperature to melt them may vary depending on what plasticizers and other agents the manufacturer added to the plastic. So a #1 plastic beer bottle may melt at a slightly different temperature than a #1 plastic Mountain Dew bottle.

    Melted plastic fumes can't be too bad or all the injection molding places and plastic extruding places would have tons of health problems. I would however recommend using a well ventilated area.

    And yes, you could use the plastic for food use, provided you stick to plastic from food containers that hasn't had harmful chemicals in them. So no reusing plastic gas cans, oil bottles, medicine bottles, or antifreeze bottles, etc. Plastic is porous and will somewhat pick up the contents of whatever is placed inside it to an extent.

    Source(s): I'm a packaging engineer and studied plastics.
  • mhw
    Lv 4
    1 decade ago

    You need a mold if you are trying to thin out the recycled plastic items you wish to use - and then you need an oven the mold will fit into. By using different types of plastic in one project, you will get different melting points - and probably undesireable results (lumps/chunks along with melted plastic). the fumes are highly toxic, so, if you want to see your work when it's finished, make sure you work in a well ventilated area! You can melt an old plastic music album over a bowl/pan in the oven at about 325 degrees for a couple minutes - gravity will make it fall over the edges of the glass or metal form/bowl and the edges will become ruffled - you can further form a little more while it is hot (use gloves) as soon as you take it out of the oven. Make sure you do not use an open flame to melt any plastic!!! Once cooled, it will not be toxic and can be used for food.

  • Anonymous
    1 decade ago

    Plastic molding is done with an injection molder. It heats the plastic pellets to the correct temperature and injects the plastic under pressure. Your method will not work at all.

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  • ?
    Lv 4
    1 decade ago

    Cautionary note-melting platics in many cases produce toxic PVC fumes. Not as much fun as sniffing airplane glue, but just as effective at destroying brain cells.You probably shouldnt try this at home.

  • Bonnie
    Lv 4
    5 years ago

    Take him to the Vet Fast. This Could be Very Dangerous. He Could be at big Risk. Better Be safe than Sorry. Keep your eye out for choking if you decide to not take action. Bring somone with you to the vets to make sure if he starts to loose oxygen on the way they can try to help.

  • Anonymous
    1 decade ago

    I would think that you need a mold.

    Also, I would not use the bowls for anything as they are toxicand have chemicals in it

  • the fumes are toxic.

    have fun with that

  • Be very careful!!

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