Writing on Plastic

Have you ever needed to write on plastic and the ink didn't stick even when you used permanent marker. Well I work in a company that prints on plastic all the time. We prepare the plastic to get the ink to stick by oxidizing the surface first. In short we pass the plastic past a flame that lightly "burns" it. But not enough to see a discoloration.

Step 1: Writing With a Marker

So you want to write something. Try writing on plain plastic.

Step 2: Ink Comes Off

Rubbing a finger across the ink causes it to come off.

Step 3: Oxidize Surface

Use a candle or in some cases a small propane torch. Quickly move back and forth so the plastic doesn't melt or get discolored.

Step 4: Mark the Surface

Mark on the area you flame treated.

Step 5: Rub the Ink

Rub on the area with marker and flame treated. It should resist coming off.

Step 6: Candle May Cause Soot

A candle may cause a soot mark like the one in the picture. Using a small propane torch instead of a candle might avoid this.

Comments

[Tech4All]

Looking for the right type and brand name of (alcohol-based?) ink, as the place of application is a slum in Serekunda/The Gambia. We prepare for local workshops on hand hygiene. The idea is to write and illustrate a message on tarp-type plastic, that is used for the handwashing station.
Marker pens are impractical. we look for something like a very small stamp cushion, that could be locally created.

[courtneypsmith]

Curious if it matters what type of marker/Sharpie is used. Would a shimmer gold/silver Sharpie work?

[Yesh24]

How long dos the heating effect hold good. Can I write on it after few days or months.

[StephanieL70]

I was curious about what would happen if I put a clear coat of nail polish on top (mine happens to be vegan and non-toxic, and if so whether or not it eliminates the need to set the marker with flame first.

[DIWesser]

Exactly what I was looking for. Thanks.

[Thejesterqueen]

it also works if you roughen the spot you are going to write on with sandpaper or an Emory board, etc.

[DIY Hacks and How Tos]

Nice tutorial.