Thermal transfer printing technology in pharmaceutical packaging printing

Drugs are closely related to people's lives. Therefore, the packaging and printing quality of drugs directly affect people's health. With the wide application of high-tech in the printing field, a variety of new and advanced packaging are emerging, and traditional printing techniques are sometimes difficult to adapt to pharmaceutical packaging with higher requirements. In the new packaging printing method, thermal transfer printing technology has been applied in pharmaceutical packaging (such as ordinary carton packaging and flexible packaging, etc.). It not only has flexible printing information changes, but also applies to the printing of different substrates and a variety of special-shaped surface, it printed labels also have a certain anti-counterfeiting effect. With the continuous improvement of thermal transfer printing technology and the development of ink and other materials, it is certain that thermal transfer printing will play a greater role in the future of pharmaceutical packaging and printing. Let's talk about the application of thermal transfer printing in pharmaceutical packaging and printing and some of the operating procedures.

Thermal transfer printing features and applications

Thermal transfer printing (referred to as thermal transfer) is an indirect transfer special printing. It uses special transfer printing paper or transfer printing film to print the pattern first, and then transfer printing to the printing material, mostly for ceramic decal printing, Textile printing, label printing, etc. Thermal transfer printing mainly includes thermal transfer printing, sublimation thermal transfer printing, deinking thermal transfer printing, flock thermal transfer printing, and thermal transfer printing.

Hot-press transfer printing: The hot-pressure transfer printing technology is firstly printed on a thermal transfer printing paper or plastic film by screen printing, gravure printing, etc., and then transfer the graphic to the fabric by heating and pressing. Leather and other items.

Sublimation thermal transfer printing: Traditional sublimation thermal transfer printing refers to the printing of sublimation transfer ink onto paper (or plastic film) by screen printing, and heating the printed paper (or film) and fabric together Pressurized or depressurized, the dye on the paper (or film) is sublimated and transferred to the fabric in a gas phase. In addition to fabrics, they can also be transferred to ceramics, metals and other products. The main feature of the dye-sublimation transfer printing technology is that the transfer image is vivid and colorful, and the effect can be comparable to printing. Different from the traditional printing, the dye in the transfer ink is sublimated by heat and penetrates into the surface of the object. After the desublimation, the colorful image is formed. Therefore, thermal transfer printing products are durable, images will not fall off, cracked and faded.

Deinking thermal transfer printing: use paper or film as carrier, printing with plastic ink, because there is hot melt adhesive material in the ink, the adhesive is generally not printed. Heat pressurization during transfer printing, the ink layer is heated and the binder melts to bond with the substrate. When the carrier is removed, the graphic ink layer can be separated from the carrier and transferred to the substrate.

Flocking thermal transfer printing: using paper as carrier, first apply a layer of hot-melt adhesive on paper, then flock on the glue surface, and then use hot-melt ink on the surface of the suede. ) Print graphics.

Thermal transfer printing: simply the process of transferring ink from ribbon media to paper or film using heat and pressure, primarily for label printing. That is, when the label passes through the print head and the press shaft of the printer, the ink is transferred to the label by heat and pressure.

Application of Heat Transfer Printing in Pharmaceutical Packaging Printing

1. Application in general medicine packaging

Pharmaceutical packaging printing was originally used for flexo printing, but nowadays more and more variable information needs to be printed on pharmaceutical packaging, which is a problem for flexo printing. Because it is necessary to print different information, it is necessary to replace the printing plate once for each printing, which is not only time-consuming and labor-intensive, but also costly. The thermal transfer printing has programmable design, the printing method is not constrained by the printing plate, and the advantages of variable information can be directly called from the database. Therefore, the flexible printing is quickly replaced once it is used.

The main application of thermal transfer printing in general pharmaceutical packaging printing is for label printing. The use of label thermal transfer printing is very widespread, and almost all of the label printing of goods. For example, when we open the mobile phone case, we can see the inside of the bar code label. In particular, behind almost all electrical products, there are some label labels printed using thermal transfer technology. Like laptops, there are even more than one sheet of labels printed in this manner. The general high-grade packing box has a product labeling and bar code label printed by thermal transfer printing. When purchasing clothes, the tag on the clothing is usually also printed with thermal transfer printing. Train tickets, boarding passes, luggage tags, etc. purchased at the train station are also printed using thermal transfer technology.

To sum up, the label thermal transfer printing mainly has the following features: (1) It can be printed in small quantities and can be printed without wastage, even if only one sheet can be used for printing; (2) The advantages of barcode are used together with the scanner to reduce manual processing. Time to reduce costs; (3) You can print all kinds of graphics on your own, especially for company logos and certifications; (4) You can print serial numbers to track products; (5) You can connect company database data for quick extraction Data printing; (6) It can be applied to the production line to track the production of the product at any time, avoiding excess material; (7) It can be used in warehouse management to keep abreast of the latest inventory; (8) It can print tickets or various tickets, and it is fast. The quality is higher; (9) According to need, can choose the high temperature resistant, anti-corrosion or paste type label printing; (10) Can print very fast, the fastest speed can reach 15 centimeters per second length; (11) add Upper cutting knife can be used for immediate cutting, ideal for ticketing; (12) computer editing, printing content and printing effect Since printing favorably; (13) the use of system integration solutions, bar code label for the media to raise the overall procurement, production, warehousing, logistics, sales and other management systems. With the maturity and popularity of label printing technology, the price of thermal transfer printers has dropped significantly. Coupled with the current price cuts for printing consumables, the cost of thermal transfer printing for labels has dropped to the cost of ordinary printing, thus making the label hot. The competitiveness of the transfer is greatly enhanced.

Thermal transfer printing of labels generally takes two printing processes. First, the raw materials are printed, die-cut, discharged, and rewound by the labeler, and then the rolled labels are printed on a bar code printer. The principle is to contact the ribbon through the heated print head, relying on heat and contact pressure to transfer the ink on the ribbon to the label material. In simple terms, thermal transfer printing is the process of transferring ink from ribbon media to paper or film using heat and pressure. When the label passes through the print head and the final axis of the printer, the ink is transferred to the label. Thermal transfer ribbons are polyester or other high density films coated on one side with a wax-based, resin-based, or mixed ink, with a lubricant on the side without the ink to prevent wear and damage to the printhead. The ribbon consists of a handle, a front lead, a carbon ribbon, and a back lead. Pull handles and front guides are in front of the carbon precursor, and rear guides are in the end of a roll (and some do not have back guides). The carbon raw material is generally made of a top coat (mainly used to improve the adhesion of the ink on the label and enhance the resistance of the environment), an ink layer (used to print and determine the use characteristics of the carbon ribbon), and an inner coating (mainly used To make the printed surface smooth and keep the ink from being released from the base of the tape), with a base (which is the carrier of the other layers, and determines the heat transfer performance), back coating (simply put it on the back of the ribbon A layer of special coating, whose role is mainly to reduce print head wear, reduce static electricity generation and strengthen heat conduction). The front lead is generally transparent or other colors. Its main function and function are to be able to print product names, company names and trademarks, etc., for marketing and promotion. The ribbon can be easily fed onto the printer through the front guide to facilitate smooth entry into working conditions. It plays an important role in protecting carbon from being stored and transported. Rear lead is mainly used as a warning, so that the printer senses the end of the ribbon, different printers have different rear lead, mainly from the aluminum (silver, mainly for reflective sensors, reflected light represents the end of the ribbon), transparent (For a transmissive sensor that allows light to pass through to indicate that the ribbon is used up), tension (for mechanical sensing, and the change in the printer's sense tension indicates the end of the ribbon). Ribbons are generally wound on paper (or plastic) shafts. The main requirement for the shaft is that it cannot be deformed and cannot slide during printing. Label thermal transfer is the use of this special ribbon, through the working principle of a print head similar to a fax machine, the carbon powder on the carbon ribbon coating is heated, transferred to paper or other types of materials. Because the coating material on the ribbon can be selected according to the need, resulting in strong adhesion, plus the choice of print media, it can ensure that the printed handwriting is not affected by the outside world. And this heating process, how to heat, can be given to the computer to control. At present, since various softwares for printing labels have been developed, it is very convenient for users. In particular, labels are often generated in general labels, and therefore have become necessary tools for such software.

Heat transfer label paper can generally be divided into two kinds of paint and no paint, their surface ink absorption and smoothness are different.

Printing ribbons are divided into wax-based inks, resin-based inks and waxes, and resin synthetic inks. Bar code printers are also available in several varieties, and some labels also need to be printed on the printed ink surface. Therefore, printers, labels, ribbons, etc. have a great influence on the quality of label printing. For example, the quality of the thermal transfer printer determines the effect of label printing. Therefore, when choosing a printer, besides considering the price, it is necessary to consider the quality. When buying, it is necessary to pay attention to whether there is technical support from the manufacturer, after-sales service, and the technical capabilities of the seller. Because the label is often printed on a special material, and the amount of printing is large, the operating environment is also more complicated. In addition, it is also very important to select suitable labels, ribbons, and other printed materials. Keep in mind that it is not the more expensive things that are more applicable, but the best choice is to choose compatible printing materials with the printer. Therefore, pay attention to the suitability of your printer when you purchase labels and ribbons. For example, when purchasing a ribbon, in addition to the need to determine the chromophore (wax, blend, or resin) of the ribbon based on the printer, the width and length of the ribbon, consider the following issues to ensure print quality:

(1) The printer features: In the thermal transfer printing mode, the ribbon and the label paper are consumed simultaneously in the length direction. In terms of the width direction, the width of the ribbon should be greater than or equal to the width of the label paper, and less than the maximum of the printer. Print width. Due to the different physical dimensions of each printer, the maximum roll length that can be loaded and the maximum width that can be printed are also different. In addition, the working temperature of the print head and the sensitivity characteristics of the ribbon also have a great influence on the final printing effect.

(2) Label paper features: Offset paper surface is relatively rough, should be used with wax-based or mixed-based carbon ribbon; and PET paper surface is relatively smooth, with the use of resin-based carbon ribbon.

(3) Durability of printing graphic: If you want to print out the label with good durability, you should choose resin-based ribbon.

(4) Hanging requirements of the label: The label should have the properties of scratch resistance, smear resistance, corrosion resistance, and high temperature resistance. At this time, the resin ribbon or the mixed base ribbon should also be selected.

(5) Print speed: In the case of high-speed printing, a high-sensitivity ribbon should be selected.

(6) Print media: Different media labels need to be fitted with different ribbons. Print media refers to the materials that can be printed by the label printer. The shapes of the media include strips, cards, and labels. The materials mainly include paper, synthetic materials, and fabrics.

The material that determines the type of ribbon used is mainly the medium. For example, Paper: Divides highlights by surface gloss (eg