On Tue, 03 May 2005 20:52:54 -0500, Richard J Kinch
wrote:

Cori writes:

How can I best glue to poly[e]th[yl]ene?

Cannot be done, for most definitions of "glue".

It can, but you need to flame flash the surface first by passing the
flame from something like a propane torch over it briefly. Flashing
is a method of surface preparation for many low surface energy
plastics, such as polypropylene or polyethylene.

Surface energy defines the ability of adhesives to wet plastic
surfaces and allow adhesion. Surface wetting refers to how well a
liquid flows and intimately covers a surface.

Maximum adhesion develops when the adhesive thoroughly wets the
surface to be bonded. The better the wetting the better the surface
contact and the greater the attractive force between the adhesive and
the plastic surface.

Surfaces with low surface energy are more difficult to bond because
conventional adhesives cannot wet them resulting in minimal contact
with the plastic surface and unsatisfactory bonds.

If you put a drop of water on polyethylene it beads, if you put it on
the same surface after flame flashing it will spread. Once flashed
even cyanoacrylate (Superglue) will work successfully on
polyethylene.

--
Peter Parry.
http://www.wpp.ltd.uk/