Thermal Printing and Ink fading

[adambenson9771]

Hello,

I am not sure if this is the right place but I would appreciate some help.

Basically I have been trying to accelerate the fading of the ink on thermally printer paper.

“Receipts are typically printed on thermal paper, a chemically coated paper that produces text and image when the heat is applied to its surface. Since this kind of paper is susceptible to heat and UV light, extended exposure to these elements will ultimately cause gradual fading. “

I am trying to work out whether there is something I can apply once to cause the ink to fade within 1-7 days, doesn’t have to be fully. I have read somewhere that I could use scotch tape on, as it has polypropylene in it which would cause what I want or getting polypropylene in pure form and applying that.

If you guys have any other ideas, it would be highly appreciated

 

[Baluncore]

There are several possible chemical systems.
https://en.wikipedia.org/wiki/Leuco_dye

How you erase it will depend on why you want to reverse or erase the image.
Will you log data then reuse the material in a loop?
The obvious solution is to use a UV lamp to erase the image. Maybe a violet LED would meet the erasure energy requirement, (depending on the chemistry).
Alternatively, for security you could heat it all to make the image black.

“What is direct thermal?
Direct thermal printing uses chemically treated, heat-sensitive label stock that darkens when exposed to heat from the thermal printhead. Leuco dye is the essential ingredient in chemistry that allows this heat reaction to take place. Direct thermal printers have no ink, toner, or ribbon. This simple design makes direct thermal easy to use. However, because a printed direct thermal stock contains the chemistry to darken throughout its life, this darkening reaction can take place unintentionally whenever the material is exposed to high heat. Similar fading can occur with UV exposure. Direct thermal substrates include a select range of paper and film with varying levels of quality, depending on topcoats. ”
https://www.iimak.com/iimak-blog?p=technology-comparison-direct-thermal-vs-thermal-transfer

 

[berkeman]

Welcome to PF.

Basically I have been trying to accelerate the fading of the ink on thermally printer paper.

I am trying to work out whether there is something I can apply once to cause the ink to fade within 1-7 days,

Well, I guess the direct heat application is too obvious, so you are trying to have some fail-safe way of fading the printing? Can you just ask the recipients to place the receipts on their window sills or something?

 

[adambenson9771]

Thank you for the answers.
I will use a thermally printed receipt as an example. I need something I can apply to it so it kick offs the fading as I would have no access to the receipt once x substance has been applied and left me . Additionally, let's say I have already printed the receipt slightly faded so further fading can be easier.

 

[Baluncore]

Leuco dyes are selected based on long life, resistance to fade.
You want the opposite, a poor leuco dye, something that fades quickly.
Do you actually want a vanishing ink ? That can be printed thermally ?

 

[adambenson9771]

Leuco dyes are selected based on long life, resistance to fade.
You want the opposite, a poor leuco dye, something that fades quickly.
Do you actually want a vanishing ink ? That can be printed thermally ?

I have looked into vanishing/disappearing ink by blueplanet but their ink is purple. I am looking specifically into something that would fade and be thermally printed.

 

[berkeman]

Thank you for the answers.
I will use a thermally printed receipt as an example. I need something I can apply to it so it kick offs the fading as I would have no access to the receipt once x substance has been applied and left me . Additionally, let's say I have already printed the receipt slightly faded so further fading can be easier.

I hope that you understand that your request sounds a bit criminal. Why do you want to invalidate the written receipts that you give your customers?

 

[adambenson9771]

I was only using receipts as an example as it is an easy one to be associated with thermal printing

 

[Baluncore]

I hope that you understand that your request sounds a bit criminal.

Maybe not criminal, but I expect that if the client was disadvantaged in any way by loss of the information, it would certainly be considered unethical, and is contrary to consumer and record keeping law in some places.

I was only using receipts as an example as it is an easy one to be associated with thermal printing

I do not want to be a part of helping you to pull off such a fraud or scam. You must realize now that the closer you hold your cards to your chest, the less help you will get.

 

[sysprog]

Whatever you ever say, you can never not have said. Destroying records doesn't reliably destroy the information on them; there could be a copy somewhere. If someone notices that his receipt is fading fast, he can take a picture of it and print it out. Along with others who have expressed misgivings, most reasons that I can readily imagine for making deliberately ephemeral records are nefarious.

 

[jrmichler]

And on that note, it's time to lock this thread. Thread locked.