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Bonding with MEK+++
Q. We are bonding different type of materials (ABS, Polycarbonate, Acrylic) with MEK / methyl ethyl ketone, sometimes the process run perfect and sometimes everything fail.
The only difference that we see is the whether, when is cold the bonding process give high retention results and when is hot the retention results are so low.
Can you please tell me if the whether affect the bonding process with MEK?
And which of the solvents (Cyclohexanone or MEK) need more time for cure?
- Tijuana, BC, Mexico
A. Hi Lizzet,
As a 'fabricator' we only used the appropriate cements for individual and only corrosion resistant plastics.
Yes, I know that MEK will also bond to PVC (somewhat but not nearly as well as THF)and and would imagine, too, that some type of bond might be acquired with acrylic ... but as far as Polycarbonate is concerned, no experience, it was to us not a very corrosion resistant plastic like PVC, PP etc. and anyhow we nearly always welded thermoplastics.
Re 'heat' ... ah, you may have a point. What can occur, will occur, is that the MEK will evaporate VERY quickly. Why don't you use the PVC cementing technique of a precoat with MEK solvent followed immediately by some PROPER ABS cement (i.e., some ABS mixed with MEK just like the commercial cement)
You might garner an idea or two by looking at the finishing com 'library' on cementing PVC.
You didn't say just what parts you are cementing ... but if you have (even miniscule) gaps, then the pure MEK by itself would probably be nbg, especially on a hot day ... but the ABS cement would be good or far, far better.
Re cyclohexanone, no idea at all! We would never, ever use it. Re curing time ... surely that depends on two things. l. The thinness of the materials being cemented 2) the presence of gaps necessitating some 'filler' material. Probably overnight at r.t. would be OK.
I hope that the above is of some help to you.
White Rock, British Columbia, Canada
(It is our sad duty to advise that Freeman passed away April 21, 2012. R.I.P. old friend).