pourable ABS resin?

[mastersword64]

Hey guys, would anyone know where to get pourable ABS resins that I could use in metal molds and rotocast to create hollow ABS parts? My friend and I are working on some parts and a machine to do injection molding is waaaayyyyy beyond our budget. Thanks.

-Shane

 

[dijinn]

Well, I don't think there is a liquid form of ABS plastic... at least one available in an A+B mixable form.

What if you used standard resin and added fibreglass powder to it? I've heard adding the resin will make it pretty strong, tough and durable.

- J.



<div class='quotetop'>(mastersword64 @ Nov 14 2006, 01:33 PM) [snapback]1357422[/snapback]</div>

Hey guys, would anyone know where to get pourable ABS resins that I could use in metal molds and rotocast to create hollow ABS parts? My friend and I are working on some parts and a machine to do injection molding is waaaayyyyy beyond our budget. Thanks.

-Shane
[/b]

 

[mastersword64]

fiberglass powder? worked with fiberglass cloth and mat before but never heard of fiberglass powder. And you just add it into normal casting resin?

 

[wilysteve]

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What if you used standard resin and added fibreglass powder to it?[/b]

This is good advice. I think the powder being refered to is called calcium carbonate. It bulks out the resin, makes it a little stronger, and takes some of the heat out of the reaction so that you get less shrinkage. You can make a slurry from this and move it around the inside of your mould until it sets up. You could also back that up with another mix, using a little bit of chopped strand (finely cut fibre glass matting) aswell to add to the strength. Just an idea

 

[StringOnFinger]

<div class='quotetop'>(mastersword64 @ Nov 14 2006, 02:21 PM) [snapback]1357500[/snapback]</div>

fiberglass powder? worked with fiberglass cloth and mat before but never heard of fiberglass powder. And you just add it into normal casting resin?
[/b]

It's called micro fibers (not to be confused with micro balloons) there is also cabosil to thicken Polyester Resin.

You can also take M.E.K. (Methyl Ethyl Ketone) Thinner and dissolve pieces of ABS into the liquid and it will turn into paste or thick liquid then it will harden once the thinner evaporates out but you will most likely get quite a bit of shrinkage doing that way.

 

[Chris Martin]

Calcium Carbonate is chalk. It normally goes under the simple name of resin inert filler powder. It's a cheaper unrefined version of talcum powder. If you mix it with polyester (fibreglass) resin you get car body filler.

ABS (Acrylontrile/Butediene/Styrene) can be supplied in sheets or as granules for injection moulding but it's formed by the application of heat and not to my knowledge available in a liquid form. If you heat it sufficiently, it will become a liquid but it will also degrade at the temperatures necessary to do this. ABS is not a resin in the strict sense of the word.

 

[mastersword64]

This is what I was thinking about

http://www.freemansupply.com/RenCast6491Polyure.htm

Basically, my buddy and I are going to be milling some metal molds and probably rotocasting parts or slushing them around. They will be used for airsoft gun parts. We are basically tired of exporting jobs from the US to say china or taiwan because it is so much cheaper over there to create projects. We would like to come up with a cheaper way to manufacture the same parts but here in the US yet stick with a great quality product.

So far you guys have been most helpful. Thank you very much. If I get these molds done and settle on a strong, cheaper, way to create these parts, I might just send you all a gift for the help. Thanks again.

Anyone know of any reputable dealers to get these supplies from? I know smooth-on is a pretty reputable company but the prices might be a little high? Anyone know of any cheaper supplier that still has good quality products? I'd really like to get the ball rolling on this within the month. Thanks again for all your help so far.

-Shane

 

[Chris Martin]

Ah, mystery solved. This is a slightly flexible polyurethane resin that mimics the properties of ABS plastic.

BTW I'm not sure MEK will dissolve ABS. It will dissolve styrene which is why it's used as a liquid cement for plastic kits but ABS requires something more tenacious like trichloromethane, dichloromethane or chloroform. Not sure it's a route you really want to pursue anyway.

 

[mastersword64]

yeah, flexible wouldnt be the way I should go. I need something sturdy and strong. You know how those airsoft kids are, always diving around and dropping guns and stuff. I need something that can take some abuse. I was on the smooth-on website and saw the A-30 Aluminum Filled epoxy casting resin. Would that possibly be strong enough to take the abuse. I guess it ha a feel of aluminum too since it can also be polished. Or would something like the Task Plastics from smooth on be better? I am looking at doing rotocastings to create hollow parts that are just as strong. I see task plastics are good for rotocastings.

 

[Chris Martin]

Aluminium filled epoxies are generally for simulating metal objects (which as you've spotted can be polished) and for casting heat resistent vac form patterns. Most epoxies of this type are slow setting so not good for rotocasting.

Generally, the harder the resin, the more brittle and breakable it is. Why don't you ask them to send samples and make a choice based on that? Tell them what you're planning so they know the best samples to send.

 

[mastersword64]

ok sent smooth on an e-mail. Should hear from them by tomorrow. Now would the easiest way to get hollow castings be from rotational casting? I know those machines are pricey too. I forgot who it was on the old RPF board but they built their own. Anybody have recommendations on building my own?

 

[GeneralMayhem]

I reccomend Cabosil as a strengthener/thinkener. A little goes a long way toward making a stronger piece.

 

[StringOnFinger]

<div class='quotetop'>(Chris Martin @ Nov 14 2006, 05:47 PM) [snapback]1357627[/snapback]</div>

BTW I'm not sure MEK will dissolve ABS. It will dissolve styrene which is why it's used as a liquid cement for plastic kits but ABS requires something more tenacious like trichloromethane, dichloromethane or chloroform. Not sure it's a route you really want to pursue anyway.
[/b]

M.E.K. solvent will dissolve ABS, we use it at work to repair cracks, tears and holes in ABS Vac-formed boat and hovercraft lower hulls how ever it takes much longer than styrene does to dissolve.

You just brush it on in layers and it actually melts and bonds back to itself.

M.E.K. solvent will dissolve ABS, we use it at work to repair cracks, tears and holes in ABS Vac-formed boat and hovercraft lower hulls how ever it takes much longer than styrene does to dissolve.

You just brush it on in layers and it actually melts and bonds back to itself.

Cabosil adds absolutely NO strength the milled fibers and micro fibers both add strength and thickness to the pieces as they are micro sized pieces if fiber glass strand. You can also use the micro fibers along with cabosil and gain some strength while thickening the resin.

 

[AnsonJames]

You can buy something called ABS resin but it's for injection moulding and not for pouring.
As far as using inert fillers you could use plaster of paris if you don't mind a bit of extra weight.

Anson

 

[Chris Martin]

<div class='quotetop'></div>

M.E.K. solvent will dissolve ABS, we use it at work to repair cracks, tears and holes in ABS Vac-formed boat and hovercraft lower hulls how ever it takes much longer than styrene does to dissolve.

You just brush it on in layers and it actually melts and bonds back to itself.
[/b]

Then I'd recommend trichloromethane, dichloromethane or chloroform as it will do the job twenty times faster. EMA/Plastruct solvent cement is dichloromethane. That and chloroform will stick most plastics including acrylic which MEK definitely won't touch.

 

[mastersword64]

i doubt ill be dissolving ABS. Too much of a hassle and the ABS is most likely weakened after that. The cure time for totally dissolved ABS that is poured into a mold is probably forever. lol Anyone have any recommendations on casting resins that I can either rotocast or slush cast which will be very strong? A reminder that the castings are being made for airsoft gun parts and body shells, so they must be able to take a beating. This is much harder finding the correct product than I anticipated. Thanks again for all the help so far guys.

-Shane

 

[Chris Martin]

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i doubt ill be dissolving ABS. Too much of a hassle and the ABS is most likely weakened after that. The cure time for totally dissolved ABS that is poured into a mold is probably forever. lol [/b]

Yes it is and yes it is. That's why plastic parts are thermo formed.