Injection moldable, water-soluble plastics

[enmo321]

Hi,
I've been researching water-soluble plastics, in particular, polyvinyl alcohol pvoh. There were some articles back in 2008-2009 from several companies that claimed they could successfully injection mold it. Does anyone know of suppliers that can currently supply raw pelletized materials, or have experience with injection molding it? Or has the need for this type of material, pardon the pun, dissolved?

My search has come up with the following:
MonoSol (IN, USA) made a product called MonoPol
Environmental Polymers (UK) made a product called 'Depart' but they've since gone out of business. Anyone know if Depart is still being made by anyone?

The application I intend to use it for is to act as a 'lost wax' core in a secondary molding process. The cores would ideally be injection moldadable (for volume).

Any other recommendations for suitable materials or suppliers would be much appreciated.

 

[MikeHalloran]

No, sorry.
All I know about PVA is that it dissolves a _lot_ faster in alcohol than in water.

Actual wax is injection moldable. Is that not suitable?



Mike Halloran
Pembroke Pines, FL, USA

 

[enmo321]

Thanks for the wax suggestion, Mike. Our secondary molding process (epoxy prepreg) is at around 150C and would need the core shape to be fairly stable.

 

[MikeHalloran]

A cheap LDPE might run out during a modest post-cure bake.


Mike Halloran
Pembroke Pines, FL, USA

 

[CoryPad]

Have you contacted DuPont?

http://www2.dupont.com/Elvanol/en_US/products/index.html

 

[ornerynorsk]

You may also want to check out the water injection or water assist techniques. I don't know how mature the technology has become, but here are a couple of articles that may be of interest. Good luck with the project.

http://www.ptonline.com/articles/water-injection-molding-makes-hollow-parts-faster-lighter

http://www.plasticsportal.net/wa/pl...lasticsportal_news/2007/07_268?doc_lang=en_GB

http://www2.basf.us/businesses/plasticportal/water_assist_injection_molding.htm

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[ornerynorsk]

Sorry, forgot to finish my thoughts. A thinner, hollow pre-form would allow use of more conventional thermoplastic materials with less material to burn out once the ceramic shell has been produced.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[enmo321]

Thanks for the input. The water injection technique is very interesting and new to me, although I'm not sure if it can be used in my application.

I did get in contact with a supplier that produces an injection moldable PVOH - Mowiflex by Kuraray. Plan to run some trials with it. Here's the link for future reference.

http://www.kuraray.us.com/products/resins/mowiflex-tc/

 

[ornerynorsk]

Thanks for sharing the link, that is interesting material!

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.