Cori wrote:

How can I best glue to polythene?


Almost nothing works.

The polythene in question is dense and is taken from the nozzle of a
bottle. I need to glue it into place.

Of course I will key the polythene with many scatches but I need a
glue which will stick to it.

Will Araladite stick to polythene?

Barely. It will stick, but almost any flexing cracks it off. Polyester
resin (car body filler ) is a bit better, but by no means a strong joint.

Will superglue stick to polythene?

No. That's why they make CA nozzles out of it.
Its a polyolefin - a naturally greasy material. Best bet is a solvent
that dissolves carrying a dissolved plastic of a different type. Maybe
contact adhesive?

I am not even sure that many solvents WILL dissolve it. Certainly none
in my ususal range of solvents do - most come in polythene bottles!

If any other alternative to using polythene exists, take it.