reprocessing TPE and PP insert molded products 2

[aseemjaggia]

hi,
I am currently insert moulding a handle wherein TPE is moulded over PP . I want to know is whether we can reprocess the scrap thus generated in the process? Also is it possible to remove TPE coating from PP product again for the purpose of recycling the products separately. If yes then how can I do this else how can this be reprocessed.

it would be good if you could guide me through this issue.

Thanks
aseem jaggia

 

[Demon3]

My best guess is that it would be impossible to separate the two and that grinding and reprocessing would be fine especially if you don’t use too much regrind as a percentage of the total. The TPE will act as an impact modifier in the PE or PP you blend it into.

Dr. Chris DeArmitt

Plastics consultant to the Fortune 500:

http://www.phantomplastics.com

Webinars on plastics, fillers & impact modification:

http://www.plastictraining.com

 

[MikeHalloran]

If you're in an area where very low cost labor is available, you could probably have people separate most of the overmolded TPE from the PP, with simple tools.

Otherwise, it's better to avoid making scrap in the first place.


Mike Halloran
Pembroke Pines, FL, USA

 

[aseemjaggia]

Dr. Chris DeArmitt thanks for your precious guidance on the matter i will surely give your suggestion a try and let you know the results. As far as Mr. mike's advice goes, sir the TPE is inseparable from PP we have tried all methods of removing but were unsuccessful, and no matter how much you try u cannot prevent a certain percentage of scrap from being generated, due to various factors. Thanks for the guidance.

 

[ShiranS]

I've been looking into this problem as well.

I came across an additive called Polymag which you can add at 1% to make either the TPE or PP magnetic. Ten you can crush it all up and seperate the magnetic regrind from the non magnetic regrind. I have'nt had the chance to see if it really works and to see if it is cost effective.

If you do go ahead with this please do let me know how it turns out. I'm not sure if it is food contact safe or if you can produce any color you wish with this additive. Eriez I think is the company.

Another idea I was playing around was if I can add CaCO3/Filler to the TPE to increase its density and there by seperate the crush material with water. I haven't tested this idea as yet.

 

[Demon3]

Density separation is common. If you want to try the magnetic separation then I may be able to help as the company I work for is the leading supplier of magnetite as a filler for plastics. Adding some of that makes the plastic stick to a magnet. I only mention it as you brought it up as you brought it up.

Chris DeArmitt PhD
President - Phantom Plastics LLC

Consulting, ideas and training on plastic materials

http://www.phantomplastics.com

 

[ornerynorsk]

That's interesting. Chris, do the different varieties of plastics themselves have enough variation in conductivity values that eddy current seperators would have any useful effect to "sort" the different materials?

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.

 

[aseemjaggia]

Thanks everybody for precious input, as per chris guidance i tried regrinding and reprocessing of coated material and it was sucessful though we had to change some molding parameters as shrinkage rate was different from pure pp material but it was sucessful. I used approx 20% regrind in the mixture. Thanks a lot chris for the information

 

[Demon3]

I'm very happy that worked out. Thank you so much for reporting the outcome. That helps us all!

Chris DeArmitt PhD
President - Phantom Plastics LLC

Consulting, ideas and training on plastic materials

http://www.phantomplastics.com