The so-called thermal paper refers to the information recording paper that is coated with color-forming materials and is stimulated by a thermal signal to develop its own color. that is said that thermal paper is to give energy (heat energy) on the surface of the paper, so that the physical or chemical properties of the substance (color developer) change.

A special coated processed paper to get the image.

Thermal paper is rapidly developed with the popularization of fax machines all over the world, but due to the development of electronic communication,

Thermal paper is not only popular in personal families in the form of fax paper, but also appears in businesses, supermarkets, banks, hospitals, airports, etc.

field. Its uses are becoming more and more extensive, the varieties are increasing day by day, and the scope of application is wider and wider. , at present, the main application fields are as follows

Down.

(1) Thermal paper for fax machines is mainly used in various types of thermal paper fax machines. There are commercial business use, but also home use and so on.

At present, thermal paper machines for this type of use account for about half of the total output, and are the main focus of thermal paper since the late 1980s.

direction. Its quality goal is to pursue high speed of facsimile recording, high density of lines (blackness) and preservation after recording. like

From the perspective of recording speed, it has developed from G2 type to G3 and even G4 type, which can reach high-speed fax of about 15S per A4 size paper.

(2) Thermal paper for printing and terminal recording In order to meet the needs of various new terminal recording equipment, different varieties have been developed, which can be

Widely used in printing records of word processors, medical testing and industrial testing, computer-aided design and production (can beCAD/CMA for short), counters, automatic cash payment machines (ATM/CD) and portable terminal printers, etc.

Receipt records for highways, taxis, etc.

(3) Thermal paper for labels and bills In recent years, new products of thermal paper have been extended to the label field, and the development is rapid. it is hot

A combination of effective paper and self-adhesive labels. Apply self-adhesive on the back of the thermonuclear paper and compound it on the release paper for printingLabel.

From the sales and supply situation in recent years, the general trend is: the first category is gradually decreasing, while the second and third categories are gradually increasing.

★Classification of thermal paper

As early as the 1930s, thermal recording technology was developed. The thermal paper used at that time was called wax paper type sensitive paper. It was coated with two layers on the support, the bottom layer was a carbon black layer, and the surface layer was an opaque stone layer. The paraffin layer becomes translucent, revealing the black quilt, allowing images and text to be recorded. Later, the heat-sensitive recording system was divided into two categories: one is the physical heat-sensitive recording paper that uses heat to make colored pigments physically color to achieve the recording effect; the other is the use of heat to produce chemical reactions to achieve color development. Purpose Chemical type thermosensitive recording paper.

Thermo-sensitive recording papers that develop color by physical methods include fusion transparent type, fusion transfer type, thermal lift type, and super-cooling method. Among them, the molten transparent type is representative.

Melting and transparent thermal recording paper adopts the principle of melting and transparency, that is, a layer of opaque wax is coated on the black base paper as the surface layer, and the opaque wax-like material is melted and transparent through the action of heat wool, and the bottom layer of the base paper is transparent. The colors are revealed to form the image. This type of thermal paper is widely used in medical electrocardiograms, electroencephalograms, or marking records of general measuring instruments in industry. However, the opaque wax layer on the surface of this type of thermosensitive recording paper is easily scratched by mechanical hard objects and reveals the underlying colored layer when unnecessary, and the recording temperature is high, and the recording needle is easy to wear. Due to these shortcomings, its use on other instruments is limited to a certain extent.

★Chemical thermal recording paper

(1) Two-component metal compound color-developing thermal paper This two-component metal compound color-developing thermal paper is based on the mixture of heavy metal salts of fatty acids and reducing agents (phenols), and the fatty acid salts are melted by heating React with reducing agent to reduce heavy metals and free color. To put it simply, at room temperature, the two hair components form a physical separation and do not develop color. After heating, a chemical reaction occurs due to thermal melting to develop color.