While digital on-demand printing is gradually beginning to move toward the market, the same thermal transfer technology with the same personalized characteristics as on-demand printing is also popular because it can print color graphics to paper products, etc. according to individual needs. On textiles, ceramics, plastics, metals, labels, and other substrates, the method is simple, low-cost, and personalized, leading to a new trend of transfer printing.
First, the characteristics of transfer printing
Transfer printing is to print and transfer the material on the carrier first, and then transfer the image on the transfer material to the substrate by using a pad printing head, thermal transfer printer, transfer printing paper or transfer printing film. Transfer printing can be printed on a substrate surface that is inconvenient for printing on a printing press, such as various forms, molded objects, or soft materials. Before printing, images and characters are engraved on the intermediate transfer carrier, and then the carrier is transferred to the substrate by special technical means such as warming, moistening, pressure, etc. to form a print. According to transfer printing technology classification can be divided into cold transfer printing, thermal transfer printing and pressure transfer printing.
1. Cold transfer printing
Can be divided into dry transfer printing and wet transfer printing.
Dry transfer printing: The carrier generally uses a plastic film. The release layer is pre-coated on the film, and then the graphic is printed on the coating, and then a layer of adhesive is printed using a sticker for printing ink. When the printing is transferred to the substrate, the carrier film can be removed.
Wet transfer printing: The carrier is generally made of paper or film, pre-coated with a water-soluble release layer, printed with printed adhesive, and the backing glue is water-soluble. When the transfer is wet with water, it is applied on the substrate and the carrier can be removed.
2. Thermal transfer printing
Mainly sublimation thermal transfer printing, deinking thermal transfer printing, flock thermal transfer printing, thermal transfer printing.
Sublimation thermal transfer printing: use paper as carrier, printing with sublimation ink, transfer printing heating graphic can be transferred to the substrate. The ink used is made of sublimation dyes, which are mostly used in transfer printing of synthetic fabrics.
Deinking thermal transfer printing: use paper or film as carrier, printing with plastic ink, because the ink contains hot melt adhesive, generally not printed adhesive. 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. When the label passes through the print head and the mandrel of the printer, the ink is transferred to the label by heat and pressure.
3. Pressure transfer printing
For pressure-sensitive transfer printing, the printing carrier is generally a film, a release layer is applied in advance and the graphic is printed, and the backside is printed with a special pressure-sensitive adhesive for printing ink. During transfer printing, the image can be transferred to the substrate by applying pressure on the glossy surface of the film.
Second, the common label transfer printing type
Label transfer printing is the use of physical and chemical methods to transfer printing patterns and colors onto substrates. Common label transfer printing methods are as follows.
1. Scrap transfer printing
It is mainly applied to hard and smooth materials such as paper, wood, and plastics. It is used in graphic design, photo albums, toy stickers, scraping music, transfer printing paper, etc. When using, remove the surface of the finished product from the label, place the pattern at the position where the printing is to be transferred, and use the nail or wood to wipe the surface of the pressure-sensitive film evenly. Tear the packaging machine'target=_blank>transparent film. Text transfer.
2. Reverse pressure transfer printing
Reverse pressure-sensitive transfer printing labels are classified into three types: solvent-resistant, scratch-resistant, and baking-resistant. Solvent-based solvent-resistant scrub; scratch-resistant grinding can be done without any treatment after transfer printing, can have good adhesion and scratch-resistant grinding effect, but to avoid scratching hard objects; high temperature baking type can be in the transfer printing After the baking treatment, it is also possible to directly perform the baking treatment without spraying the oil. Pressure-sensitive transfer printing labels are suitable for hard materials such as metal, plastic, and synthetic materials, such as air conditioners, refrigerators, washing machines, water heater housings, fishing rods, clubs, bicycles, and other surface decorations. When using, simply peel the protective film, apply it to the transfer position, and evenly press and tear the bottom paper to complete the pattern transfer.
3. Water transfer printing
Can be divided into reverse water transfer printing labels (B, C transfer printing labels), soluble forward water transfer printing labels, strippable type forward water transfer printing labels. The characteristics of water transfer printing labels are beautifully printed, colorful, suitable for a wide range of materials, strong and beautiful labels, and not easy to change color, especially for irregular surfaces. Since the graphic film layer of the water transfer printing label has a certain toughness, when the moisture under the layer is scraped, it is important to wipe the edge while keeping the pattern flat on the irregular surface. After the film is fully dried, it can be sprayed with varnish and baked, but it must be fully dried. Otherwise, bubbles will appear after baking, resulting in waste products.
4. Thermal transfer printing
Thermal transfer printing is to print a pattern on a special transfer paper or transfer film first, and then transfer printing to the substrate, mostly for ceramic decal printing, textile printing, product label printing, and the like.
Third, the superiority of label thermal transfer printing
In recent years, with the advancement of science and technology, thermal transfer technology has also undergone rapid development. The main feature of thermal transfer is that the transfer image is vivid and colorful, and its effect is not only comparable to ordinary printing, but also thermal transfer printing. Under high temperature, the thermal transfer ink can be sublimated by heat and penetrate into the surface of the object to form a bright and colorful image. Therefore, the heat transfer products are durable and the images will not fall off, crack and fade. The thermal transfer application has a wide range of applications, from fabric printing to surface printing of ceramics, metal, glass and other crafts, various labels, barcodes, and stickers printing, especially in the area of ​​label printing.
To sum up, label thermal transfer printing has many advantages:
(1) Small amount of multiple printing, no waste, even if only one sheet can be used for printing; (2) Using the advantage of barcode, with the use of a scanning gun, manual processing time can be reduced, and costs can be reduced; (3) Various kinds can be printed according to need Graphics, especially the company's logo and certification through the mark; (4) can print serial numbers, tracking products; (5) can connect to the company database data, rapid extraction of data printing; (6) can be applied to the production line, at any time to trace Production of products to avoid surplus materials; (7) can be applied to warehouse management, keep abreast of the latest inventory; (8) can print tickets or various bills, fast, high quality; (9) can be selected according to need, high temperature resistance Corrosion or sticky label printing; (10) Fast print, up to 15cm/s; (11) Can be cut immediately after printing, ideal for tickets; (12) Computer editing, print content and print results No less than printing; (13) the use of system integration solutions, using bar code labels as a medium to comprehensively enhance the procurement, production, warehousing, logistics, sales and other management systems. With the maturity and popularity of label printing technology, thermal transfer printers and consumables have all undergone substantial price reductions. The cost of thermal transfer printing for labels has dropped to the cost of ordinary printing, greatly enhancing the competitiveness of thermal transfer of labels. $Page break $
Fourth, the label thermal transfer printing should pay attention to the problem
The thermal transfer printing of labels usually goes through two printing processes. First, the raw materials are printed by a labeler, die-cut, discharged and rewinded, and then the rolled labels are printed on a bar code printer. The principle is that the heated print heads are the same color. With contact, the ink on the ribbon is transferred to the label material by heat and contact pressure. The thermal transfer ribbon is coated on one side with a wax-based, resin-based, or mixed ink polyester or other high-density film, and a lubricant is applied on the ink-free side to prevent wear and damage to the print head.
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 precursor is generally composed of a top coat, an ink layer, an inner coat, a tape base, and a back coat.
Top coat: used to improve the adhesion of ink on the label and enhance the resistance of the environment;
Ink layer: used to print and determine the characteristics of the ribbon;
Inner coating: It can make the printing surface smooth and ensure the consistency of ink release from tape base;
With base: the carrier of other layers determines the performance of heat conduction; back coating: is a special coating applied on the back of the ribbon, which can reduce the wear of the print head, reduce the generation of static electricity, and strengthen the heat conduction.
The front lead is usually transparent or other colors, its main role is the printable product name, company name and trademark, etc., for marketing and promotion. The front belt can be used to easily put the ribbon on the printer, smoothly enter the working state, and protect the carbon in the storage and transportation. 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 aluminum plating, transparency, tension in three ways.
Aluminium: silver, mainly for reflective sensors, reflected light indicates the end of the ribbon.
Transparent: Used for transmissive sensors, allowing light to pass through to indicate that the ribbon is used up.
Tension: used for mechanical sensing, the change of the printer's sensing tension indicates that the ribbon is used up.
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 fax-like print head, the toner coating on the ribbon is heated to the paper or other types of materials, due to The coating material on the ribbon can be selected according to the needs, resulting in strong adhesion, and the choice of print media can better 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 control, and various softwares that have been developed specifically for printing labels are very convenient for users, especially the generation of bar code symbols has also become such The necessary tool for 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 three types: wax-based inks, resin-based inks and waxes, and resin synthetic inks. There are also several types of bar code printers, and some labels need to be printed on the printed ink surface. Therefore, printers, labels, ribbons, etc., have a great influence on the print quality of labels. Thermal transfer printer quality determines label printing