Preparing/cleaning bare steel & powder coated paint to receive adhesive tape/film UHMW-PE & PTFE
I'm going to apply a couple types of plastic film/sheet and tape to a few pieces of mechanical equipment that need a low friction surface (reduce
material build up). The metal is standard stamped steel that has been abraded from "high velocity" material (wood, metal, plastics, some small
rock/dust, etc), so it is bare and pretty smooth. There is also some painted area which I'm guessing is powder coated (electrically charged then
baked on) which I'll apply the film/tape to.
The adhesive is reported to simply be "acrylic" adhesive and is reported to be very sticky and strong.
I was considering cleaning with things like acetone, methanol, ethanol, IPA or ammonia solution - I also have MEK if that would be better. I've read
that these can sometimes leave residue or film, IDK. They are all technical grade (painting supplies). Another option I was considering was an acid
or blend of acids. I have HCl, H2SO4, HNO3 and could get phosphoric if that would be better. IDK if the best solution would be using a solvent
(allowing to fully dry) followed by a brief acid wiping (diluted) afterwards? If there is another method which would give the best surface to receive
the tape, I'm very interested.
I guess I could prep the metal buy sanding with anything from 40-400 grit sand paper if that would help in any way. Or I can sandblast with very
aggressive media down to a bead blast satin finish.
The film and tape are two different types I'm trying - well 3. One is a PTFE sheet & tape, then UHME polyethylene sheet & tape then the
UHMEPE with a PTFE coating. Both the PE and PTFE are pretty slippery and tough so I'm interested in seeing which will hold up better and which allows
the least material to adhere to it.
I've come across something called "PBAN Polymer - polybutadiene/acrylic acid" which looks like it can be used by itself as a super sticky substance
(reported to be like the stuff on fly paper strips) or a curing agent can be added to make it an epoxy. It's also used in rocket engines for the solid
rocket booster. I'm interested in getting some of this to see if it may work well as an adhesive but min purchase of 1 gallon is a little much ($30).
On a side note I came across a "how to" on USPlastics.com on how to bond UHMW PE, which seems useful
http://www.usplastic.com/knowledgebase/article.aspx?contentk...
Since I don't want to break copyright, here is a brief outline:
1. Clean both surfaces with something like alcohol - allow to dry
2. Roughen areas to be bonded together - it says 4-0 sandpaper which I think is 150 grit
3. Use a flame to oxidize both surfaces (handheld torch) using a few quick passes - the material shouldn't get so hot it blisters
4. Apply adhesive to both surfaces and allow to dry until it is sticky (follow adhesive directions)
5 Apply pieces together and clamp well (tightly) - allow to sit minimum of 12 hours (longer better) or how long the adhesive states it needs to sit.
Temp, humidity and moisture can play a big role in how long the bond will last and choosing the correct adhesive is crucial if it is going to be in
harsh conditions.
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