What is the strongest way to bond styrene to polyethylene

[John Smith 47Participant @johnsmith47]

Hello

I need to bond styrene (HIPS) onto a fairly waxy looking solid polyethylene (PE).

Mechanical background:
I need to attach piece of styrene which is about 5mm x 10mm wide to longish piece of solid PE (about 1 ft long). I dont know whether it's HDPE or LDPE (and I'm not sure if it makes much difference in this case!)

Apparently one option would be to use CA (Cyano Acrylate glue) having first used a primer.

For example:

A) "LOCTITE PLASTICS BONDING SYSTEM" has been suggested
**LINK**
Which contains a special activator and claims to work on plastics including "polyethylene and polypropylene"

OR

B) Deluxe Materials
I was in touch with Deluxe Materials who suggested:
1) Tricky Stick ("surface primer"
**LINK**
and then:
2) Roket Rapid ("Highest quality cyanoacrylate"
**LINK**

I don't know which of the above is more likely to work.

From what I can see, epoxy glues seem unlikely to work on polyethylene at all!

Cement
Maybe there is something very clever one could roughening the surface with microscopic hole and then just use cement the styrene and squeeze together??

Either way I think I shall resort to some sort of metal pinning as well.
e.g. I am thinking I might
– screw a couple of small screws into the body of the polyethylene,
– chop their heads of and then
drill a couple of matching holes into the styrene and then
put some CA/superglue onto the stubs of the screws and then
– stick the stubs into the two holes in the styrene.

It's just that finding a way to the styrene to PE with glue would definitely help and will also be v useful to be able to do without resorting to screws etc every time!

Thanks

 

Edited By John Smith 47 on 09/11/2015 23:26:19

[John Smith 47Participant @johnsmith47]

[David JuppParticipant @davidjupp51506]

Sticking anything to Polyethylene is tricky, because it is non-polar. Specialised primers can help.

In industry, either high voltage discharge onto PE surface, or a very brief exposure to a gas flame is used to 'treat' polyethylene immediately prior to printing or lamination. Both processes introduce polar groups onto the surface of the polymer. The treatment can decay over time, especially when mobile additives are present in the polyethylene.

You could try a brief waft through a (blue) gas flame – if you can see any change, you've probably over done it.

Even with surface treatment, I would not expect you to achieve a particularly strong bond.

[Steve PaveyParticipant @stevepavey65865]

Looks like you already have your answer. You're right that epoxy will probably not work – I mix epoxy in polythene bowls, and when cured I can usually peel out the remains easily. Roughing up the surface with a coarse grit paper might change that, but whether the bond would be reliable long term I don't know.

A pdf article here **LINK** has a fair bit of information, but as it is a sort of scientific paper it doesn't give any trade names so isn't much use in practical terms in telling you what to go out and buy.

You might find that Sika do something that you can use – I've used various types of Sikaflex for marine and construction work, and I know, for example, that they do an adhesive to bond plastic shower linings to plasterboard.**LINK**

[Neil WyattModerator @neilwyatt]

I would fit some threaded inserts (see Mark Noel's article in MEW earlier this year) and have some screws to keep the thing secure as belt and braces.

[John Smith 47Participant @johnsmith47]

> Mark Noel's article in MEW earlier this year

Sounds promising however I am not yet a subscriber to MEW.
Is anything available on line?

[Michael GilliganParticipant @michaelgilligan61133]

John,

I don't know if it's any help, but I just remembered this stuff

I'm bewildered; but hopefully, Jeff Dayman can explain how they do it … it's a very slippery material with a self-adhesive layer. [more detail, here]

MichaelG.

Edited By Michael Gilligan on 10/11/2015 22:36:35

[VersabossParticipant @versaboss]

I can recommend the method given by David Jupp. A short waving with a gas burner until the surface looks shiny, and then gluing with a good cyanoacrilate worked perfectly for me. I have to mention that my stuff was possibly polypropylene, and black! I have lots of this stuff in about 25 mm thickness, and I needed a much thicker part for a connecting piece to the shop-vac. Still holds after several years of rough treatment!

Regards,

HansR.

[FatgadgiParticipant @fatgadgi]

Hi John

I am watching this thread even closer now as I have never had any real success bonding PP with adhesives.

One method that you might think about is Hot Plate Welding which is widely used in production and bonds like the proverbial. It's used for PP and it's used for ABS and I know it can sometimes be used with dissimilar plastics, but I have no idea whether yours are compatible because if the PP is unfilled, the melt temps are quite different.

The principle is easy enough – two surfaces are pushed against a hot aluminium plate which melts both interface surfaces. The plate is removed and the two parts pushed together. Almost Instantly bonded.

Could be worth some playing around ?

Cheers – Will

[John Smith 47Participant @johnsmith47]

> Could be worth some playing around ?

Conceivably. Except that I don't currently own a gas burner which is probably a mistake! (Can anyone recommend a nice small scale torch?) Also it will be a pain to lose geometry… but possibly worth a go if all else fails.

Meanwhile I have taken to drilling tiny holes and inserting needles on a push fit basis. I did try bonding using CA glue (CyanoAcrylate – from Loctite). Unsurprisingly of course it only bond at the metal-styrene end and not at that metal-PE end. [sigh]

J

[MuzzerParticipant @muzzer]

Get some polyolefin primer. Designed just for this application. Presumably that is included in option A) in the OP. Works well and lasts for years.. Tools for the job….

[John Smith 47Participant @johnsmith47]

Posted by Muzzer on 11/11/2015 19:45:38:

Get some polyolefin primer. Designed just for this application. Presumably that is included in option A) in the OP. Works well and lasts for years.. Tools for the job….

Interesting… how well does it work in practice? Have you ever tried it yourself ?

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