blow mold casting

[LonnieFisher]

Does anybody know if it's possible to do blow molding at home? I'd like to try it but haven't got a clue how to do it.

[AAAAA]

what you need is a 2 part mold, and thick wall bottle like plastic Called a" Blank".
You need to evenly heat the Blank until it almost in a Fluid like state than place it in the 2 part mold & close it.
(The mold should be warm to hot)
You need an air compressor to pump hot air into the blank. this would allow it to expand in to the mold.
the thickness on the item depends on the thickness of the blank .

[AAAAA]

here's

http://www.youtube.com/watch?v=oR0gMKN58kY

http://www.youtube.com/watch?v=1ztl0i6rgyY

This is not blow molding but table draping Or reverse vac u forming
http://www.youtube.com/watch?v=LfShSGcFgos

[TrueDave]

My teeny airbrush compressers have been loaned out

Would canned air work ?

[AAAAA]

not enough pressure from both. depending on the thickness of the blank and the size of the mold
you would need 50 to 100 pounds as bear minimum. pounds of pressure .

[ThatBatmanGuy]

^^ Also a mold that can withstand that type of pressure. Not really a do it yourself hobbist craft.
Bob

[LonnieFisher]

I'd like to make blow molded body parts like Mego did. My Hulk parts would be awesome being blow molded.

[LonnieFisher]

^^ Also a mold that can withstand that type of pressure. Not really a do it yourself hobbist craft.
Bob

A resin mold could stand that much pressure. Or even plaster. A silicone mold with a support shell would probably work, too.

[drzaius1]

I happen to be a blow molder. Not toys though, I make bottles.
It would be difficult to do this at home. You would be better off with a simple rotational molding set up. You would need a two part mold that would withstand enough heat to melt the small amount of plastic beads. You could then preheat the plastic to molten consistency and then put it in the heated mold. You would close the two mold halves and rotate the mold continually until the plastic has covered the entire internal old surface. The mold would also need to be really hot too. We run our machines at 340 defgrees F but I'm not sure what you would need for a small amount of plastic over a longer period of time. You would continue rotating the mold until it cools. Do not rotate too quickly or shake it or you will get bubbles in your walls of the form. After it cools carefully pop it open and cut off any flash you don't want. You should probably coat the molds with some sort of release agent such as silicone spray, prior to filling the mold. You only need enough plastic to form the desired thickness of the parts walls. This will produce a hollow part similar to a chocolate easter bunny.


Take care.

[LonnieFisher]

I happen to be a blow molder. Not toys though, I make bottles.
It would be difficult to do this at home. You would be better off with a simple rotational molding set up. You would need a two part mold that would withstand enough heat to melt the small amount of plastic beads. You could then preheat the plastic to molten consistency and then put it in the heated mold. You would close the two mold halves and rotate the mold continually until the plastic has covered the entire internal old surface. The mold would also need to be really hot too. We run our machines at 340 defgrees F but I'm not sure what you would need for a small amount of plastic over a longer period of time. You would continue rotating the mold until it cools. Do not rotate too quickly or shake it or you will get bubbles in your walls of the form. After it cools carefully pop it open and cut off any flash you don't want. You should probably coat the molds with some sort of release agent such as silicone spray, prior to filling the mold. You only need enough plastic to form the desired thickness of the parts walls. This will produce a hollow part similar to a chocolate easter bunny.


Take care.

Thanks for the advice. I do already rotationally cast parts using a two part liquid resin. The parts I want to blow mold don't roto-cast very well, but that's probably how I'll end up doing it. I'd just love to be able to cast all things in all ways. I wish I had a mini, home-style plastic injection set-up!

[AAAAA]

an mold to take that kind of punishment either blow molding or roto casting, need to made out of aluminum alloy at the very lest.
and a powered spinner would hepl in rotocasting.

[ThatBatmanGuy]

^^ Exactly what I was talking about. A resin nor plaster mold would NOT hold up to that type of punishment. This type of production is more on the industrial level. Also, don't think we are trying to put you down Lonnie. Just trying to be helpful.
Bob

[livnxxxl]

Doesn't melting plastic put out a potentially harmful putrid smell? I am looking at this from a personal level. I know big business has ways to deal with the harmful fumes (smell) better than a person doing it at home.

I have been wanting to cast using melted plastic to. I just want to make sure that I go about it safely and intelligently. I have some of those low melt plastic beads although I have yet to try them.

[AAAAA]

Doesn't melting plastic put out a potentially harmful putrid smell? I am looking at this from a personal level. I know big business has ways to deal with the harmful fumes (smell) better than a person doing it at home.

I have been wanting to cast using melted plastic to. I just want to make sure that I go about it safely and intelligently. I have some of those low melt plastic beads although I have yet to try them.

Yeah In a work shop with ventilation exhaust fans system ,
not good in the house.

[TrueDave]

I originally wanted to get into plastics because sculpture made from Bronze wood and stone is just too heavy.


I had a Art teacher tell me he took a job in a plastic factory to learn how to do this stuff. Only worked there a month or two to get the hang of it.