I know I started a thread about cutting plastics, but I didn't want the two topics to intertwine. I was wondering if any one you had experience/knowledge of custom molding plastic objects? What I want to do is copy a plastic object. Maybe with silicone molds?
Custom molding plastics
- Thread starter kyazh
- Start date
legendaryfrog
Tactical Refreshment Action
I make orthotic insoles for peoples shoes, and we use RCH thermoplastics to form over top of plaster casts.... what are you trying to form?
Basically, I want to replicate a plastic object. An example would be auto emblem.
I want to take the shape of this object, maybe with a silicone or cast mold. Then somehow in that mold, use clear plastic to make the clear version of it.
I want to take the shape of this object, maybe with a silicone or cast mold. Then somehow in that mold, use clear plastic to make the clear version of it.
what you would want to do, since you already have a positive mould (the logo) is get some plastic, lexan would be best i think, otherwise the stuff we use at work is unobtainable to the general public.
You need to heat it up in the oven until it is really soft and plyable.
Our plastic at work begins to "melt" at about 375F after 10 - 15 mins.
Now there are two ways you can form this thing, the latter being the harder but really the only way to do it.
The first requires a "blotter". Which is a metal pan with a lid that contains a rubber membrane, this is connected to a vaccuum pump.
Once the pump is turned on, it sucks the air out of the blotter, pulling the rubber membrane down, and forming the plastic over the positive mould. it actually does a really good job and getting into the tight spaces, like corners and such.
after about 10 mins once the plastic is cool, you relieve the vaccuum pressure, and pop the positive mould out of the plastic.
You could build one of these perhaps if you had access to a vaccuum pump.... because it wont work with a household vaccuum motor.
The other thing you could do, is after the plastic is hot and plyable,put it over top of the positive mould, and form it over the mould by hand.... but make sure you have gloves, plastic is EXTREMELY hot.
just keep working it over and into the positive mould by hand, until the plastic begins to solidify.
then you can cut out the shape with such tools as a bandsaw, and polish up the edges with a buffing wheel.... a bench top grinder mounted wheel with some diamond white buffing compound makes for real nice edges.
A dremel buffing bit will work too, but will take much much much longer to finish.
EDIT
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The thicker the plastic, the longer it will take to become plyable, and the harder it will be to form over and into intricate designs, and corners, so i would suggest using 1/8" lexan.
You need to heat it up in the oven until it is really soft and plyable.
Our plastic at work begins to "melt" at about 375F after 10 - 15 mins.
Now there are two ways you can form this thing, the latter being the harder but really the only way to do it.
The first requires a "blotter". Which is a metal pan with a lid that contains a rubber membrane, this is connected to a vaccuum pump.
Once the pump is turned on, it sucks the air out of the blotter, pulling the rubber membrane down, and forming the plastic over the positive mould. it actually does a really good job and getting into the tight spaces, like corners and such.
after about 10 mins once the plastic is cool, you relieve the vaccuum pressure, and pop the positive mould out of the plastic.
You could build one of these perhaps if you had access to a vaccuum pump.... because it wont work with a household vaccuum motor.
The other thing you could do, is after the plastic is hot and plyable,put it over top of the positive mould, and form it over the mould by hand.... but make sure you have gloves, plastic is EXTREMELY hot.
just keep working it over and into the positive mould by hand, until the plastic begins to solidify.
then you can cut out the shape with such tools as a bandsaw, and polish up the edges with a buffing wheel.... a bench top grinder mounted wheel with some diamond white buffing compound makes for real nice edges.
A dremel buffing bit will work too, but will take much much much longer to finish.
EDIT
-------
The thicker the plastic, the longer it will take to become plyable, and the harder it will be to form over and into intricate designs, and corners, so i would suggest using 1/8" lexan.