Where the
world gathers for metal finishing
Q&As since 1989


-----

Painting polypropylene and polyethylene

How can I prepare polypropylene and polyethylene for accepting nickel paint (paint has a Butyl Acetate, Toluene, N-Propyl Acetate and Amyl Acetate base)?

fred beihold
- boston, Massachusetts
1999

---

PP & PE are polyolefin plastic with waxlike surface. The paintability of these types of plastic is no good at tall. For PP, a primer-promoter coating is required. Bayer or Nippon Paint may supply. For PE, acid treatment (0.5-1% phosphoric acid might help)or corona discharge method is applied prior coating.

You may use HVLP (High Vol Low Pressure)gun for spraying which tends to give a more even film build than the conventional air gun.

Regards

Fred Yeung
Hong Kong
1999

---

Hi Fred, As the 'other' Fred pointed out, both PP and Pe are awful to paint due to their non-stick waxy surface. Neither are truly cementable. Ditto for fluorocarbons. However, if you have a part where the paint goes the whole way around (i.e., not on one flat surface), then you could get a fairly good apparent bond if the paint itself is flexible and 'shrinks', as all paints do, onto the part. Which is why a Polyethylene pipe when painted with latex all the way around has an apparently good bond, an elastic bond, so to speak. Anyhow, this was just an idea which probably doesn't pertain to your problem.................but is food for thought. Regards,

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
1999

I am a chemical engineer in major of polymer. In my opinion paint and painting are very attractive . Therefore I have decided to learn about them. Three months ago I didn't know anythings about painting but today I know many things about them such as powder & liquid spray coating , electrocoating , composition of paint, etc. I have a question from you. What is the best method for painting of polymer material such as PE, PP, POLYAMIDE(PA), etc ? Please explain the surface treatment stage for preparing plastics before painting. I will be glad if you help me. Thank you very much.

Ali yavarnia
mashhad -khorasan-Iran
2000

---

Is it possible to make by itself the PP primer ?

Thanks & regards,

Richard Bui
- Hanoi, VIETNAM
2001

---

The question I have is for Freeman Newton. He made a very interesting statement with respect to the adhesion of paint to pipes. Have you experienced this phenomena with other shapes or do you feel that the pipe shape best lends itself to aiding in adhesion. Any thoughts or comments are welcomed.

Paul Kenny
Winona, Minnesota USA
2002

What is the best method for painting of polymer material such as PP ( bumper ) ?

A. Sabeti
employee - Tehran
May 25, 2008