Ultrasonic or even hot air welding are possibilities.

Try several schemes on small samples. I remember when I worked in research for a major chemical company, one division came up with a type of plastic by compounding two different types of plastic as a trial and error attempt and the result was excellent but I wont go into further detail. So give it a go.

Thanks for the reply guys!
The problem is that I don't own the machinery so trial and error will be time and money consuming.
CoryPad - I read that for Ultrasonic, the melting temperature difference (I guess it meant Tg) of the polymers to be joined have to be <20 degrees Celsius (between ABS and PET its 40oC). Also in tables I found of Ultrasonic welding, it appear as not weldable together.
Do you have any positive experience doing it with ultrasonic?
Also, since the PET sheet is very thin, I'm afraid hot air will practically tear the sheet
Your advise is mostly appreciated

IMHO, you are onto a bit of a lost cause. Both materials are hygroscopic, so heating them to weld without pre-drying will cause bubbling.
Even adhesives will be problematic - cyanoacrylates work well with ABS (as well as skin!) - not so good with PET.

I hope your results differ...

H

Chicopee: There are many compounds of plastics - ABS is made from three polymers.

www.tynevalleyplastics.co.uk

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