Digital Thermal Transfer Technology Improves Flexible Packaging Level

Flexible packaging is the most important category in the packaging industry. The output value of flexible packaging products exceeds half of the packaging industry.

A variety of paper, plastic, paper, plastic, plastic aluminum flexible packaging is widely used for packaging snack foods, dry goods, baked goods, candy, chocolate, frozen fresh food slices, frozen foods, coffee, tea, powdered food, bags Drugs, hardware parts and other goods.

In order to ensure the safety of foods and medicines, real-time information such as production dates and product lot numbers is printed on the flexible packaging of foods and medicines, and has become an important part of the production process of foods and pharmaceuticals. Real-time information enables manufacturers to track products when needed and provide protection when recalling products on a large scale. It can be said that coding technology has become an important part of modern quality systems.

Flexible Packaging Technology Introduction

The traditional flexible packaging coding technology relies on letterpress printing to create images using characters on the letter holder. The image is mechanically embossed or rolled onto the film surface.

Common letterpress printing techniques include hot stamping, wet ink, and one-touch ink marking machines.

In recent years, the continuous inkjet printing system (CIJ) has also been applied to flexible packaging. Inkjet printers print ink through the print head to print a variety of data on primary packaging and paper boxes, including simple date codes, logos, bar codes, and serial numbers.

The traditional letterpress printing technology and continuous inkjet printing system have their own advantages, but there are also many shortcomings, such as the traditional hot-carbon ribbon coder and ink wheel coder can not print in real time, need to manually update the date and batch number, The traceability is limited; on the print, there is no standard LOGO, bar code, or rotary image printing method, and each printed character needs character fonts. In production, hot carbon ribbon coder needs “preheating time” before operation, and “cooling time” when it is necessary to change information, which will prolong the production time, and once the character size is not accurately aligned, it will cause packaging film. Worn out. In addition, font wear or loss can make the print result unreadable, while the length of the hot carbon ribbon is also relatively short, the average length of domestic ribbon is only 100 meters; the ink of the ink printer needs time to dry out or may be dirty Traces and stains require special cleaning fluids to be cleaned, and most ink cartridges need to be warmed up (up to 30 minutes after heating the ink wheel) and need to be cooled before changing the code content.

Continuous inkjet printers have the advantages of wide application range and simple operation. However, fonts, character options, logos or barcodes are limited, the print quality is general, the printing direction must be consistent with the moving direction of the substrates, and the print heads need to be cleaned regularly and replaced regularly. Filters, cleaning of floors stained with ink, machines, conveyor belts, etc., and the special inks and solvents used for them often contain harmful substances and may require venting and other devices.

The latest laser and digital thermal transfer coders can greatly improve the problems of traditional coders, especially digital thermal transfer coders, which can improve the traceability of products while improving the code quality. , To improve the reliability and flexibility of equipment, suitable for a variety of flexible packaging materials.

Digital thermal transfer coding technology advantages

Technological innovation usually means that new technologies can bring higher product quality, faster production speeds, lower production costs, more reliable operating performance and higher product added value.

Digital thermal transfer coder is mainly composed of print head, print ribbon and controller. Printheads typically contain 8 to 12 dots per millimeter or 200 to 300 dots per inch (DPI). These dots can be quickly and continuously switched to transfer ink from ribbon to film to print images. Thanks to digital means, the coder can print "in real time" and change batch number and date information very quickly for batch and continuous packaging.

Thermal transfer printers use two types of print heads: flat and bevel. Among them, the flat head type print head belongs to an earlier technology. Although the cost is low, the resolution and the printing speed of the print image are not ideal; the bevel type print head technology is new, and can provide a faster print speed and a higher resolution. Some recently introduced thermal transfer printers mostly use bevel type printheads such as Marken's SmartDate and 18 series thermal printers.

The thermal transfer ribbon is usually a three-layer structure consisting of a backside coating, a PET film, and an ink layer.

The surface coating improves the adhesion of the ink and improves the resistance of the ribbon to chemical and environmental factors. The ink layer is a mixture of wax, resin, and pigment used to print images on the film surface, while an electrostatic coating (usually silicone) can lubricate and reduce static electricity to protect the print head.

Ink is divided into "soft ink" and "hard ink". Soft ink is mainly composed of wax and pigment. The melting point and the energy of the print head that needs to transfer the ink to the substrate are relatively low, and are mainly used for paper materials. Hard ink is composed of high-melting synthetic chemicals and pigments. It requires a high energy from the print head to transfer the ink to the substrate. It is mainly used in polyethylene or in low temperature environments; combining wax and resin can be used. The ink layer has the advantages of both inks, can achieve high-speed printing, and can form a good adhesion on most packaging films, suitable for most application areas.

In general, the thermal transfer ink's adhesion is directly proportional to the cost, and the higher the ink's adhesion, the higher the cost.

Digital thermal transfer suppliers will generally provide intermittent, continuous, and other types of equipment to accommodate vertical form-fill-seal lines (VHHS) or horizontal form-fill-seal machines (HFFS) such as Marken's SmartDate 2 / 3, 18 series heat transfer coder has intermittent and continuous type. In addition, there are also the latest batch-continuous integrated device models to choose from.

On an intermittent packaging line, the print head carriage moves on the packaging film while the film is at rest. The stepping rate of the printhead carriage motor is directly related to the linear motion of the carriage, and the length of time the dots are energized is determined based on the linear velocity; on the continuous packaging line, the graphic is printed while the packaging film is moving. The length of time the dots are energized is determined based on the ribbon speed, which is controlled by the data provided by the high speed synchronizer. The control box determines which points will be energized and when.

Compared with traditional thermal carbon coder, ink wheel coder or continuous ink coder, digital thermal transfer coder has technical advantages and practical benefits.

First of all, digital heat transfer printers do not use fonts, so there is no need to align and adjust small fonts, thus avoiding the danger of the characters falling into the food or breaking the film, and the cost of replacing the characters; second, digital thermal transfer Can provide high-quality coding effects, coded image resolution up to 300 dpi, and print quality consistent and stable; can print special characters and barcodes, can be a large number of graphics or special characters pre-stored in the gallery, in the Automatically change the code when the machine is down or without human errors, so as to maintain a high level of production capacity; it can print real-time information and improve the traceability of products, which is particularly important in today's increasingly focused on food and drug safety.

Affordable digital thermal transfer technology

Although digital thermal transfer coding is the latest marking technology, it is not unattainable. In fact, the digital thermal transfer coder is a product that ordinary users can also use. At the same time, it is also a Reliable technology. To date, Magneon has installed more than 40,000 thermal transfer printers worldwide, making it not only the laser coder market, but also the leader in digital thermal transfer printers.

There are not many manufacturers that can currently provide digital thermal transfer printers, but since the success of Markon's global launch of digital thermal transfer devices, the huge market has attracted a number of inkjet giants such as Videojet. The corresponding product.

Following the SmartDate 2/3 and 5 series, Marken introduced the 18 series of low-cost thermal transfer coders in November 2006, thus forming a complete product line in the digital thermal transfer coder market. Users can The code quality, production speed, and materials used are different to select the heat transfer coder that suits their needs.

Take the Markem 18 series thermal transfer coder as an example. This series of equipment uses a wax/resin type ribbon, which is suitable for printing on many films, has a very high adhesion and print quality, while maintaining a low cost. Its print head is 32mm, print resolution is 8 dots/mm, 200dpi. The coder supports variable data printing for special fonts, barcodes, and logo prints as well as shelf life dates. The image memory can also pre-store up to 100 images with a maximum ribbon length of up to 500 meters.

It is worth mentioning that the 18 series of thermal transfer printers support USB interface. Customers only need to use a small U disk, you can replace the coded content, so that on-site operation is more simple and flexible.

18 series thermal transfer has intermittent 18i and continuous model 18c. The 18i Intermittent Coder prints images by moving the print head while the packaging material is stopped, while the ribbon remains immobile during printing; the 18c continuous coder prints when the packaging material is moved, ribbons and packaging materials Move at the same speed.

Although digital thermal transfer printers are more expensive than traditional thermal printers and ink printers, their excellent coding quality, real-time coding capabilities, and flexibility in printing fonts, icons, and barcodes are sufficient. The stringent requirements of today's food and pharmaceutical packaging have increased the level of coding of flexible packaging to a new level, providing the most ideal solution for flexible packaging today.

Reprinted from: Good Packaging Network