foam extrusion and mold?

[snowrocka]

Hello,

I have a kind of fundamental question or maybe just an error in reasoning?
Is it possible to extrude PS into a mold and let it expand in there to get a XPS foam in surfboard size with the same quality of an XPS block? Then the extruder would have to portion the material, maybe over this gas pressure method. Or is it impossible to achieve low densities then.
The reason is to reduce the waste when you mill the surfboard out of an XPS block.

Besides, can anyone tell me the costs of such an XPS extrusion line that produces boards with a thickness of around 150mm?
And what is the price for an EPS molding machine in comparison to that?
Coulnd't find any information about that on the net and I also don't want to contact a company right away.

Thankyou
Regards

 

[patprimmer]

What do you think they make EPS packaging shapes with.

I am sure some time on Google would turn up something.

The real cost would be the different moulds to accommodate the fickle fashion trends in the surf board industry.

Regards

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[snowrocka]

Thx, but I know that EPS is also used as a packaging material, that they use those machines there and also how they work. I spent already two days on the net searching for methods, prices etc., otherwise I wouldn't post in here.

The thing is the difference between EPS and XPS, so expanded and extruded PS. XPS has better structural properties and, important for surfboards, less water absorption. Thats why I have an interest about foaming XPS in a mold after is comes out of the extruder instead of letting it run and run, becoming thick long plates.

The mold would be just a few standard forms, which is big enough to fit several surfboard designs into. After that you can mill out all the different shapes you want to.


Regards

 

[Pud]

Was not two-pack rigid polyurethane foam once used for such cores - ready for a layer of GRP?

H

 

[snowrocka]

hey,

yes it was. But after the closure of the biggest surfbblank manufacturer Clark Foam, because of environmental and health issues, new core-materials are on their way. Most of the companies use EPS now, just a few still use PU. XPS is not used that often because of the outgasing.

greetings