Before molding try to treat the surface by using PTFE spray

Leonid V Vladimirov Sir,

God Bless You.

There is a special sprayer you can use it before the compression moulding

Basheer AlShammari Sir, can you unlock the special spray very thankful

to you.

Dear Bhaskar:

If you consider my advice as valuable - then please check/mark my answer

"Recommended".

Best Regards,

Leonid

MOULD RELEASE SPRAY;there is many types try PTFE

Basheer AlShammari SIR CAN YOU suggest me other than PTFE

Dear Bhaskar Bhatt:

PTFE - poly-tetra-fluoro-ethylene -- (CF2)n - became a general name for co-polymers of CF2 - all of them are often called by using the general name "Teflon", but actually they are copolymers of (CF2). Two of such co-polymers are PFA and PFE - by using Key Words: PTFE, PFE and PFA - you can find all the formulas through the Google Search.

You are trying to choose the (CF2)-containing polymer in order to maximally reduce the adhesion to your Mould. But most of Researchers (including myself) try to choose the "Teflon"-co-polymer which will give the maximal adhesion - thus we are trying to solve the opposite problems. According to my experience PFA and PFE - show better adhesion to Polyimides and/or Metal - that is why i recommended you the to use homo-polymer (CF2) i.e., PTFE.

But since the results you obtained do not satisfy you - please try to use PFA and/or PFE suspensions which are also available as spray(s). It may happen that these sprays will do better for you than pure PTFE - but I doubt it.

Please try - and inform me about the results.

Leonid

Did you consider shrinking? May be you have, because processing conditions, a too small contraction or to high, depending of the geometrie of your part.

Add a Kapton film on and below the powder you mold

It easily peels off after molding

try to peel it off while the mold is still hot.

Dear Alisa:

Of course you are right.

I have been working with such systems over 20 years.

And in my comment I actually discussed - which type of fluoro-polymer should be sprayed over the Kapton film - this is so obvious that just "flew out of my head"

Kapton film does work as a good anti-adhesive,

but the combination Kapton covered by one of Teflons - is superior.

Best Regards,

Leonid

Dear Bhaskar:

Prof. Alisa Buchman and me gave you the best answers to your question.

I can assure you - no one will give you a better advice.

Mold sticking could be due to the following:

(1) Negative Draw, which means that the Mold has some "under-cut" crevices, into which some small amount of the Polymer could flow and when solidified, removal is difficult - and may be not possible. The Answer to this Problem is to smoothen out the undercut and make sure that the Mold is without any negative draw;

(2) Many materials may need Full cooling to lower temperatures, before "stickiness" goes off. This problem is answered by Cooling the material to normal temperature;

(3) If the Mold is not smoothed out, even small "lines" could become undercut crevices that hold the product and removal may be difficult. Answer to this would need that the Mold is finished and polished. Perhaps one may resort to Hard-Chrome Plating after finishing to make easy removal of Product, apart from improving Finish and luster;

(4) In case all of these fail, one must use (after completing all of the above, in steps) Mold Release agents (usually Silicones) which are available as Sprays... There are many Manufacturers/suppliers... Here is one .. http://aerolgroup.com/products/productsafra-heavy-duty-silicone-sprays/ ... Also... one may Google and find out some one nearest to own location... Best regards

Leonid V Vladimirov thanks sir

God Bless You.

Just put Kapton on the wall of the mold. It works

put deionized water to remove the film

HI!

I have a similar problem but my polymers are intended for medical implant use.

Is PTFE still relevant?

Use film-assisted-molding. Check our web-site: www.boschman.nl

use aluminum foil to prevent sticking

For lab use, you can use Kapton film as suggested, but for industry fast production, you must have mirror shine mould with fast cooling rate as suggested too.