Thermopaper Technologie and Usage

The per capita usage of Thermo papers in Europe has doubled over the last years and has reached a level of  approx. 5 sqm/per capita

This growth is determined by differentiation in useage, the excellent bar code possibilities, easy to use and the low cost of ownership with the Thermo-technology. Technically the high system reliability and the low maintenance rates are clear advantages .compared to competitive technologies.

The growth in paper consumption happened even despite the fact that the market for direct Thermo Fax has shrinked dramatically during the last years. Areas of growth in usage are cash register rolls, Self adhesive Labels, Lotto receipts, Tickets for Transportation and Entertainment, Bank Statements, and different kinds of long term charts (medical, weather, earthquake watch).

These different areas of usage need papers with quite different characteristics and features. 

The major contents of the Thermo coat are different Colorformers (Leuco Dyes), Co-reactants, Meltingpoint-regulators, and Binders

Leuco Dyes are natural colorformers which do not reflect visible light when not developed. After the development through the Co-reactant the molecular structure changes and the colorformer reflects (visible) light. (In Case of Thermo usually Black). The Colorformers have the tendency to return to their original structure, and become invisible again. That is why all Thermo papers have a limited Archivability.

Archivability/Reistance
In Europe Papers with Archivability of 5-25 years are produced and offered. In Japan Papers with up to 99 Years are offered.
The circumstances under which the archivability is tested are: 21C; +/- 50% relative humidity, dark storage in non soft PCV cabinets, these are the standard Paper storage conditions. Influences like UV-Sunlight, Softeners, Oil, Fat, and Water will shorten the archivability time, as they have a direct influence on the molecular structure, so that the image returns faster to “invisible”.

As basic rule one can say, that the cheaper the used colorformer is, the less resistant the image is against the prescribed influences.  

The following Tableau should give an overview of the different Thermo papers with their Resitance/Archivability:

Dynamik Sensitivity
Another very important technical factor is he so called „dynamic sensitivity“. The faster the paper is pulled through the printer, the less time has the paper to react and create the image. That is one of the reasons why all Thermoprinter Manufacturers approve different papers, because only the correct paper will create an image which reaches the full image development on the thermocoating. This factor is measured by the optical density. A full black image has an optical density of  +1,3, a Barcode is still readable at an optical density of 1; Human eye readability is still given at Optical density of 0,6 (Grey). The full development of the image potential of the paper is also important for the archivability, if the image is not fully developed; time of archivability will be lost.
 (Graph dynamic Sensitivity)

Static Sensitivity
Next to the Dynamic Sensitivity, Static Sensitivity is a characteristic of Thermo papers.
The Static sensitivity is not as the dynamic Sensitivity a “Quality” issue, it is just a performance issue for the user. The static sensitivity only gives an indication at which temperature level the image will start to develop. Presently almost all standard Thermo papers in Europe have a starting Temperature of approx. 70C, Papers with 90C and 110C starting temperature are available.

Lifetime of Thermo printers
If the right paper with the correct printer setting is chosen, Thermo printers should have a lifetime for more then 100 km print out. Papers with a too rough surface, wrong Binders and wrong Printing inks can reduce the Lifetime of Thermoprintheads dramatically, as well as cutters can wear out very fast when non approved materials are used.

Thermo papers and the environment
All European Thermo papers can and should be recycled.
All the Thermo papers which are used by Nakagawa in Europe have the ISEGA approval for direct contact with food.
Most of our POS papers are produced under the Nordic environmental Label “SWAN” for Paper Production under low total emission values.
Our Self adhesive Label- and Ticket materials are certified DIN 71.3 for the use with Children’s Toys.

It is Nakagawa`s aim and policy to offer all customers the “right” product under all above aspects for long term customer satisfaction.

Thermo printing-is the easy way to get variable Data onto a sheet of paper, it is not the answer to all printing questions, but at the right application, with the correct product it is fast, reliable, cost effective and easy.
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Nakagawa Germany,
Horst Judisch