polymer in india

Hi

I am an engineering student frm India. I want to build a reprap. But the trouble is that I am not getting the polymer(polycaprolactone) anywhere. Is there any other alternative polymer that can be used ?
Or can poycaprolactone be prepared in a lab ??
Is there a dealer with international service ? BUT this is the last option that I would like to try as the cost converted to Indian Rupees is very high.

Thanks a lot for your help.

You can get polycaprolactone from you local Solvay agent.

If you are looking for an alternative plastic that behaves somewhat like polycaprolactone you might want to try PVC. The melting points of the two are about the same.

Keep in mind that I have not tried PVC. I've just looked at the data sheets.

Thanks a lot for the advice on PVC I will look it up

Hi
i checked uped in wiki abt PVC it has a melting point of > 200C now hw can I use it ? I would have to look for better things for the extruder.

After reading your post I surveyed the literature and found a bunch of references giving a PVC melting point of about 212C. On the other hand I've found others which specified about 80C like this one...

[www.dynalabcorp.com]

and this one.

[www.polymerweb.com]

[www.plasticsusa.com]

[www.dynalabcorp.com]

I allow that I am quite baffled by this. I know as a practical matter that you don't dare use PVC piping for plumbing hot water lines in buildings, a restriction that argues for a low melting point or at least a low deflection temperature for PVC.

Forrest,
I don't know if this adds anything but I have a piece of electrical sleeving which is marked "PVC TUBING 105 C". It is "springy" when cold. In boiling water it becomes "floppy" but does not melt.

Edited 1 time(s). Last edit at 07/04/2007 03:00PM by nophead.

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[www.hydraraptor.blogspot.com]

It's like there are two very different PVC's out there.

wikipedia saves the day!

[en.wikipedia.org]

"PVC is commonly used as the insulation on electric wires; the plastic used for this purpose needs to be plasticized."

It looks like the lower temperature, 87 degrees, is actually the glass transition temperature rather than the melting point. This is what I crossed when I put it in boiling water. It loses its rigidity and becomes "rubbery" but does not turn into a liquid and flow.

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[www.hydraraptor.blogspot.com]

"Flow" is a rather peculiar term to use with plastics given their very high viscosities. You can heat up HDPE to 50 degrees over its melting point and still have to wait hours before it begins to form a proper puddle.

Well this stuff is all new to me but PVC definitely changes state at 85C but it doesn't become a liquid, not even a very viscous one. I read the glass transition is a brittle to flexible change. Although I would not describe my PVC sleeving as brittle it does spring back when bent. At 100C it does not hold its shape as a tube or have any spring to it. It just flops about. When I cool it down again I still have a tube not a puddle.

I think HDPE is different in that it does not have a glassy state, or if it does is well well past it at room temperature. I presume if I raise PVC to just above its melting point at 212C it will become a viscous liquid like HDPE does.

This has implications if you want to push PVC through the extruder. It may go floppy at the top end of the barrel long before it melts.

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[www.hydraraptor.blogspot.com]

Sounds like you need Matweb.

[www.matweb.com]

I've been using it since college (2002) to do material lookups as I go about my day (electromechanical applications engineer is probably the best term for what I do).

You need to poke around a bit, but Matweb has quite a good listing of material properties. If you bore down to a specific manufacturer (as I did with HDPE + Bottle + FDA to see what's qualified for food service in the US, say milk bottles) they'll provide their recommended processing temp ranges for various possibilities (extrusion, blow molding, thermoforming, etc.)

I think that I'm going to give Jim Waring at New Image plastics a call and ask him what temperature he extrudes his PVC filament at.

Hello
I am a polymer engineer and a supply manager from Iran.I have one problem for producing rigid PVC granule. I would like to know can i produce PCV rigid granule in the same compounding extruder as producing soft granule?
Thanks.

I have probleme with rigid pvc granules in my 80 mm , L/D 25:1 extruder which is not melting at 180 C I have 4 heating zones