The solid ink is melted, converted into a liquid, then sprayed or piezoelectrically driven onto the media. One major advantage of solid ink is that the ink does not have to dry. Instead, it solidifies almost immediately on the printing media surface. In addition, the solid ink does not dry out, nor does it require a wick as liquid ink does. Solid ink bounds to the paper surface producing colors that are more vivid and sharper images.

Solid Ink Printing

In 1995, Tektronix development indirect printing and revolutionized solid ink printing. Tektronix used an ink-jet printhead that spray-painted a complete image on a spinning drum. Once the image was applied to the drum surface, it was transferred from the drum onto paper. This concept made it possible to use a very simple paper path, with the paper being feed straight through the printer similar to that of an offset printing process. However, this indirect printing process places severe restrictions on the ink. The ink had to be hard at room temperature, have a low melt point and had to be able to easily jet through the tiny apertures of the printhead. In addition, the ink had to solidifies almost immediately on the drum surface and stay in place on a rapidly spinning drum. Lastly, the ink had to transfer from the drum to paper during the offset printing step. This led to the development of the solid inks used today.

The solid ink resembled that of crayon-like cartridges. The color quality of solid ink printing is stunning. In addition, its print speeds exceeded most equivalent-priced laser printer, due to the fact that it prints colors in a single pass instead of having to make four passes. The Tektronix-developed technology applies all four-color solid ink mirror images onto the drum in a single pass.

Thermochromic ink has various applications including high quality promotional items, advertising, labels, packaging, security documents, textiles, toys, novelties, and anti-counterfeiting for such items as event tickets, lottery tickets. Thermochromic ink can also be used for safety as temperature indicators and warnings for such items as hot drinks and food.

It contains microencapsulated thermochromic pigment that changes from color to colorless as the temperature rises, when the temperature decreased the pigment returns to normal. In aqueous conditions, the pigment is encapsulated, resulting in a slurry mixture, resembling that of plaster-of-paris.

The microcapsule wall of the pigment can endure most standard mixing and application procedures. However, if too much force is used during the mixing or application procedure, the microcapsule will be crushed, and the ability of the ink to change color will be destroyed

For businesses that print an occasional label, they do not require a separate label printer. However, if that send out mailers, fliers, and print multitude of various size labels an inkjet or laser printer would best meet your needs.

The type of labels most frequently used will fit most word processing applications, which come with templates for labels. There are also several programs for other print options, such as labels for CDs and DVDs, which also can be printed with the use of an inkjet or laser printer.

However, for printing large volumes of labels, the purchase of a dedicated label printer can be helpful. Dedicated label printers can vary in price from under $100 for small consumer printers, which can print rolls of labels to labelers that cost over $300, which can print labels for large mailings quicker and with better print quality.

These label printers are thermal transfer printers, which are also used in countless industries for the printing of bar code labels as well as postage labels. These printers use a heated print head to melt the ink contained on a wax ribbon, which transfers the ink to the paper producing the desired graphic. These labelers do not produce the quality of graphics as the industrial labelers produce, but it will be satisfactory for label text and simple graphics.

The majority of the labelers on the market receive data directly from your computer, however there are a few, which have recently appeared on the marker that have a keyboard enabling you to enter data directly into the device, freeing up your computer.

Types of Label Printers

Desktop labelers-are designed for light to medium duty and can accept a roll of stock up to 4″. They are perfect for home office use, are quiet and inexpensive.

Commercial label printers-These can accept a roll of stock up to 8″ and are suited for medium volume printing. These are used for small business and office use.

Industrial label printers-designed for industrial use, and continuous operation in warehouses, distribution centers, and factories.

When applying thermal graphics, only one pass is needed to adhere the graphic to the item. This is a cost effective technique when compared to silk-screening and hot stamping printing techniques. Other advantages with this process is that the graphics can be added to packages, contain up to 14 colors or four-color process. In addition several finishes such as matte, shiny, semitransparent, and opaque are available.

The use of thermally applied graphics allows manufactures to decorate various products of various surface textures and materials. This process also has the ability to use multiple colors and reproduce complex design with accuracy, consistency and sharp detail.

1.Direct and Thermal transfer printers are roll fed. This means they only print the number of labels or tags that are required for that particular print job without the waste of unused portions.

2.Both Direct and Thermal transfer prints are built to withstand any industrial environment, which can prove difficult for a laser, and inkjet printers to function.

3.Direct thermal printing does not require a ribbon, or ink, has a very low operational cost, as well as upkeep. It is an excellent print option for documents and labels that do not require to be kept for long periods of time. In addition, it has proven to be a successful print method for restaurant, store receipts, bar code labels, etc. However, the life span of the direct thermal printed tag or label is short and will fade over time or will turn black when exposed to heat or strong sunlight.

4.Thermal transfer printers do require the use of a printer ribbon. However, thermal transfer printer’s offer a flexible format, graphic capability, high quality printing, required very little maintenance, and high density bar code capability including the ability for infrared scanning.

Flexography was named due to its originally uses as a method for printing the uneven surface of corrugated cardboard. The flexible printing plate remains in contact with the surface during the entire print process, producing a smooth and even finish. When this process was first used, it had a very low print quality. However, great advancements have been made in the last few decades in improving the plate material and the method of which the plate is created. Today, photographic exposure is used which is then followed by chemical etch. However, some manufactures also use direct laser engraving. Because of these advancements, full color printing is now possible.

Flexographic printing is still the most widely used printing method for flexible packaging. However, with the major advancements of thermal-transfer printing an increasing number of companies are switching from flexographic printing to thermal transfer printing. One reason for this is the growing global market and the increasing number of languages and internationally understood symbols, which are required on packages. In addition, in order to comply with European and United States market and FDA regulations, packages must clearly display lot codes/ numbers and expiration dates. This had made the use of flexographic printing plates, which now require constant updating very expensive.

In order to comply with packaging regulations an increasing number of manufactures have turned to thermal-transfer printing. This simple programmable technology is not bound by the limitations of having to physically create a printing plate, but instead can program the needed information directly into the a database, which the microprocessor translates and makes the needed changes to the graphic image.

However, flexographic printing does have its loyal followers. With new and improved inks and plate materials being developed, flexography is still an appealing option. This is especially true for companies who are requested by, their clients to print unvarying information and provide preprinted packaging materials. Therefore, what we are seen in the in-house packaging printing market is a union between flexography and thermal-transfer printing.

Flexography VS Thermal Transfer Printing

Approximately 70% of the films used for packaging are printed on using flexography due to its versatility and its inexpensive operating cost. Another reason why flexographic printing is still used is that it is more suitable for printing on foil, films, and DuPont’s Tyvek brand spunbonded olefin than thermal transfer printing is is. In addition, flexographic technology also produces excellent print quality at high speeds, with flexographic printers having the ability to print hundreds of feet per minute. This makes it even more appealing and economical for large volume print jobs. Flexography ability to print on much wider webs at faster speeds does not harm print quality in fact; many supporters of flexography find it produces finer lines and logos.

However, the main disadvantage of flexography is its inability to compare to the ease of thermal-transfer printing when it comes changing text content. With flexographic printing when any part of the text or codes requires updating the users must change printing plates. Many times this means creating new print plates that can cost as much as $500 each. However, with thermal transfer printing, the user simply enters the changes into the system with a few keystrokes and the change have been made and sent to the printer, costing the company only the time needed to enter the new data.

Packagers routinely faced the problem of frequently having to make print changes due to the market demand for bar codes, lot numbers, and expiration dates as well as the need to print in multiple languages. This need for frequent changes can cost a company an estimated $150,000 to $250,000 per year on printing plates for multiple languages as well as ever changing expiration dates and lot numbers.

Still, many manufactures feel the over all cost of thermal transfer printing is too expensive when compared to flexographic printing despite the drawback of having to create new print plates.

Wax ribbons-these are the least expensive ribbon and are used for printing onto thermal transfer paper labels. The life of these labels can extend for several years when kept dry and not subjected to certain chemicals or oils that could melt the wax image.

Wax-resin-these ribbons are used on thermal transfer paper as well as synthetic labels used for pharmaceutical labels, drum and pallet labels, inventory control, and labels for mattress and pillows. Wax-resin ribbons produce a finer image on very smooth paper or coated paper labels and are more durable than wax. However, they are not waterproof and can only withstand slight contact with water.

Pure resin-these ribbons are specially formulated to print on thermal transfer synthetics labels such as polyester, polypropylene, and vinyl. The resin ink is extremely durable to abrasion, oils, solvents, and extreme temperatures. The ink dissolves or melts slightly into the plastic surface of the label, which gives it its durability. These synthetic labels are often used for outdoor labeling, UL/CSA applications, pharmaceutical labels, drums, pallets, dry-cleaning labels, automotive and aircraft, as well as manufactured parts.

Color thermal transfer printers cannot vary the dot intensity and the images must be dithered. Dithering refers to a technique used in computer graphics, which creates an illusion of color depth using a limited color palette. When the precise color is not available in the palette a diffusion of colored pixels from the available palette are used. The human eye however perceives this effect as the actual color. Often when enlarged, dithered images can be distinguished by a characteristic graininess.

Color thermal transfer printers cannot compare to today’s thermal dye transfer or dye sublimation printers, inkjet printers, or color laser printers. Color thermal transfer printers are commonly used for industrial label printing because of its water resistance and speed. In addition, because of their limited number of moving parts, these printers are considered highly reliable.

Solid-Ink Printers

Tektronix was the first to develop the Solid-Ink or Phaser printers. In 1999, Tektronix’s printing operations were sold to *Xerox. Phaser printers use wax blocks, which are melted then transferred onto the paper using a piezo inkjet head, similar to the process of the inkjet printers. The Phaser printers can be configured so that they produce extremely high-quality images. They are also more economical than the traditional color thermal transfer printers, as the only wax used is that for the printout, instead of consuming an entire ribbon panel. Operational expenses including upkeep and ink are comparable to color laser printers.

*Xerox is a registered trademark and not a verb to be used when referring to copying a document. The Xerox Corporation is concerned about this ongoing practice of using its corporate name as a verb, for this places its trademark in danger of being declared a generic word by the courts. To combat this problem the company has engaged in an ongoing campaign to convince the public that Xerox is not a verb.

To print, thermo-sensitive paper was feed between the thermal print head and the platen. The printer then transmits an electrical current to the heating resistor of the print head. The heat activates the thermo-sensitive coloring layer of the paper, which changes color, producing the desired pattern. This method reduced the cost of printing, was much faster and quieter than dot matrix printers, and it portable. Thermal printing became the common printing technique for bar codes, receipts, medical print outs, faxes, and several other applications.

However, the print did not have a long life. The thermal paper used was sensitive to UV rays, extreme temperatures, and chemical vapors. Researchers needed to enhance thermal printing. By the late 1970′s, they had a revolutionary breakthrough with the development of the ribbon films, and improvements in the printer head used in what is called thermal transfer printing.

By the 1990s, thermal transfer printers were considered one of the most accurate forms of printing. Today, thermal transfer printers are still considered as one of the most accurate printing techniques due to the fixed position print element, with print spaces measuring as small as 0.0001 inch. Thermal transfer printing never skips a space and always gives a smooth surface finish. The wax ink that is used coats the surface, providing a polished looked that is presentable and appealing.

Intermittent applications such as self-adhesive label applicators the print media is stationary, the print head come in contact with the ribbon that then comes in contact with the print media. The print head moves over the ribbon, completing the printing process.

Continuous applications the print head fixed. The printer head lowers and contacts the ribbon and substrate. It is then the motion of the ribbon that completes the printing process, not the print head. With this process, the ribbon and print media are calibrated to move at the same rate, producing top quality images.

Thermal transfer coders are a digital technology that can automatically updated lot codes and best-before dates, reducing the risk of operator error. Thermal transfer coders work in combination with several varieties of continuous-motion and intermittent-motion packaging machinery.