The deflecting electrode in a continuous inkjet print head stirs the ink drop, which eventually forms a part of a letter or code. The deflecting electrode in the print head generates power and thus stirs the electrically loaded ink drop into the desired direction.
The barcode is an optically-electronically machine-legible writing, consisting of several wide and parallel bars and gaps. With optical detectors (known as barcode readers, so-called scanners) or cameras the writing is read automatically and electronically processed. In contrast to the 2D Data Matrix code the barcode is only one-dimensional.
There are many different types of barcodes – according to their purpose and applicability. Almost all marking and coding systems are able to produce these codes.
Batch tracing offers the possibility of tracing back products to their manufacturers, to the content or to special ways of producing or features of the products. Furthermore product marking with a batch tracing serves the producer in case of callback of damaged products. Especially in the supply chain of food business, the trade of pharmaceutical products as well as in the automotive and the aircraft industry , the batch tracing is very important. Batch tracing can be a reality with industrial inkjet printers from LEIBINGER . The coding machines print content such as LOT numbers, best before dates or codes for batch tracing onto products.
Continuous Inkjet (CIJ) is a non-contact form of high-speed printing used to apply variable information such as dates, text and logos on different products. CIJ Inkjet printing is fast and can print on almost all kinds of materials regardless of size, shape and texture.
CIJ printer is the short form for continuous inkjet printer. This kind of printing is primarily used for coding and marking of products.
In the technology of CIJ printers a pump directs fluid from a reservoir tank to one or more small nozzles which eject a continuous stream of drops at high frequency. The drops pass through a set of electrodes which impart a charge onto each drop. The charged drops then pass a deflection plate which uses a field to deflect the drops which should be printed. Undeflected drops will be collected and returned for re-use. The high drop ejection frequency of CIJ printers gives a capability for very high speed printing and is suitable for applications such as date coding on beverage cans, cable or packaging.
See also the LEIBINGER CIJ printers.
See CIJ printer.
Coding and Marking describes the method to print information and data on different surfaces.
All kinds of products have to be marked and printed on with for example lot number, best before date or other information.
In continuous inkjet technology, a continuous stream of ink is separated into individual droplets in the print head of the inkjet printer.
A portion of the droplets in this stream of color droplets are electrostatically charged. Then the droplets pass through a deflecting electrode where they are deflected depending on their charge. Droplets without a charge are fed back into the ink circuit through the gutter. Charged droplets are put onto the paper.
The two-dimensional DataMatrix code is an advancement of the one-dimensional barcode. With the DataMatrix code information is very compactly displayed in a square or rectangular zone as pattern of dots.
Information in the DataMatrix code is displayed in two layers, in the horizontal and the vertical. In contrast to the barcode, with the DataMatrix code much more information can be printed and thus the information density can be increased. It is often used for labelling in the automotive engineering, with analytical apparatuses and instruments (chemical and pharmaceutical industry) but also increasingly used in the handling of documents (tickets, mailing).
The DataMatrix code ensures that in case of illegibility of 25% of the information fields, the data can still be read without error, for example when parts of the code are covered or destroyed. This advantage of the high readability is ensured by redundant data, which is present in different parts of the DataMatrix code and encoded by the ECC (error correction code).
The DataMatrix code offers a significantly higher security against fraud and is much safer to read than the barcode. Because the DataMatrix code offers the ECC, it replaces more and more the barcode.
Date coding is the marking of each product after production with a date. Every product produced on site has a batch and date code which allows each ingredient or part to be traced back to origin and makes each product fully traceable. Date coding is used in each branches from the pharma industry, food industry, automotive industry, electronic industry, cable industry to cosmetic industry and beverage industry. This can be either the date of manufacture or expiration, the best before date , the sell-by date or the use-by date. These dates serve the customer and the producer. The customer gets security by dates like best before, use-by or sell-by especially of perishable goods like food or cosmetics. The best before date is a recommendation for best flavor or quality. The use-by date is the last date recommended for the use of the product while at peak quality and the sell-by date tells the store how long to display the product for sale, the customer should buy it before the end of this date. The manufacturer knows by the date coding in which shift the product was produced. Therewith a complete traceability of the product is warranted.
Without date coding: Date coding of products is not required in generally although dating of some foods is required by more than 20 states of the USA, there are areas of the USA where much of the food supply has some type of open date and other areas where almost no food is dated. In such cases a secure traceability is not given and also for the customer it is difficult to identify if the product is fresh and can be used. Therefore especially in the food industry date coding is very important otherwise it could lead to serious health damages for example by germs or mold.
Global standards product dating is not worldwide generally required by Federal regulations and there is no uniform or universally accepted system on date coding. Depending on the packaging, device size, product type, manufacturing country, producing factory and subsidiaries, date code formats vary significantly by supplier or even within suppliers.
With the integrated automated "Sealtronic" nozzle seal in all LEIBINGER inkjet printers the nozzle and the gutter tube of an inkjet printer close airtight. This prevents the drying of ink in the print head. Even after long-term shut-down of the printer, an instant start without cleaning is guaranteed.
This unique feature guarantees an immediate start of the printer without cleaning or additional maintenance and without preventive measures after turning off or before start-up. Due to the nozzle seal, the nozzle is automatically sealed hermetically.
The nozzle and the return line will therefore not come in contact with air and any drying of ink will be prevented. A fully automatic nozzle seal on an inkjet printer guarantees an excellent instant start performance and the highest reliability with the lowest maintenance effort.
Highspeed printers are famous for their high performance at heavy duty conditions. They are applied in such cases, where large numbers of items must be imprinted at a very high speed.
Highspeed printers are integrated in the conveyor lines and have to adapt to the high speed of the manufacturing machines. The producer LEIBINGER has the highspeed printer JET3 and JET2neo in its range of products.
Industrial inkjet marking is used for most different applications in the industry. The suitable technology for these special applications is the Drop-on-Demand (DOD) and Continuous inkjet (CIJ) technology. LEIBINGER inkjet printers meet specific requirements for product marking in different industries like aerospace, automotive, electronics, food, medical and packaging industries. Industrial Inkjet marking includes printing best before dates on eggs, packaging or for example on cables.
Small character inkjet printers are also known as inkjet printers or CIJ printers (continuous inkjet). These printers are only used in the industry in different areas. Small character inkjet printers are for example used in the packaging industry, food industry but also in the cable, electronic, pharmaceutical, automotive or beverage industry . The product marking is fast and contactless.
In a small character inkjet printer the ink comes as jet over the nozzle through the print head to the product to be printed. Behind the nozzle is a piezoelectric converter which divides the ink jet into evenly drops. In the following charge electrode the individual drops will be variably strong charged electrostatically. Depending on the power charge the drops will be more or less deflected sideways in the deflection plate. The charged drops end up like this on the product or when not charged directly in the gutter tube to return to the ink circuit.
There are two different methods at the drop charging. The Binary-Deflecting-Method either transports the drop to the product or deflected to the drip-catcher. The Mulit-Deflecting-Method shoots the drops to the product with a more or less deflection depending on the power charge. With this it is possible to print a wider line with one nozzle.
Depending on the distance of the print head to the product the width of the line can vary. However, the resolution of the print will get worse with increasing distance to the product. Solutions with new technology out of the history small character inkjet printers are known as problematic by a lot of users.
The reason for this is that when these products were launched in the industry the small character inkjet printers weren’t developed very well and therefore very problematic. On the other hand to work with fast drying inks is problematic because the ink could dry in the very small nozzle after shut-down and clogg the nozzle.
If then the printer has been started after a while, errors occurred which could only solved by complex cleaning procedures, maintenance or replacing of spare parts. These problems have been sold with the technological development of small character inkjet printers. Depending on the manufacturer different technics are now implemented to prevent a drying of the ink. For example with the nozzle seal “Sealtronic” in all LEIBINGER inkjet printers which closes the nozzle airtight.
Cables are produced at individual length. The cable length can reach from a few hundred meters up to a few kilometers. The printing on the cable is as individual as the length. Some clients only need a meter marking on the cable – others also want the cable description printed on the cable.
But a marking system not only has to meet these requirements, it also has to deal with different cable diameters. That is the reason why inkjet printing systems are mostly used for cable printing. The non-contact system can print on almost every surface, in any shape, if round, vaulted, waved, rough or graded. Inkjet printers are programmable and can mark the most complex engineered harnesses at non-stop high-speed.
The cable printing will be printed automatically after a quick set up. No matter if a single or a large piece run should be produced, the print jobs start automatically one after another, without any changes at the production line.
Camera systems are used in order to guarantee industrial quality requirements of products and product marking. Furthermore they can be used for measuring reasons in the quality control. Cameras in industrial use are very robust and have a high picture quality.
At the beginnings of camera systems, mostly verification systems with a serial interface have been implemented. Today systems are in use where the data transfer from camera to the processing computer is done by digital interfaces like USB, FireWire and Ethernet. Camera systems differ into two types: Matrix cameras and linescan cameras.
Matrix cameras save the read picture information in form of pixels in lines and columns. They always save the complete picture information which on the other hand leads to a reduction of the frame rate. To enhance the reading speed there is the possibility to summarize several pixel, however this reduces the picture resolution.
Besides the matrix cameras in the industry linescan cameras are commonly used. This type of camera only has one light sensitive line (linesensor), whereas a two dimensional sensor has several linesensors to save the pixels on the processor.
The advantage of a linescan camera is the high speed processing of data as well as the larger data storage. Compared to a matrix camera, one line only needs minimum chip storage space. Furthermore a bigger area can be scanned and lines can be faster read than space.
In the industry, camera systems are used for quality actions and sorting methods. In the process the verification systems are mounted above the product to be read, only the product moves. By the aid of a sensor the camera gets the starting signal to flash. Depending on the light of the surrounding and on the contrast between product and readable information, one should work with filters and diverse lamps.
Coding means the applying of marks, the printing of fonts, text, graphics or logos on a surface. To place this information on products, several technics are available. It can be done for example by hand, with stamps, imprinting, print technics, engraving or laser.
Some producers print the coding on labels or use any other signage technology. Depending on the product surface and the sustainability of the printed information, different kinds of machines are used.
All kinds of products are coded with logos, warning information, lot numbers, graphics, best before dates, 2D Codes, DataMatrix codes or barcodes for information and traceability reasons. Different branches of the industry have to obey different kinds of regulations concerning the product coding.
In the pharmaceutical industry for example it is important, that information on instruction leaflets are without mistakes. Another very important field for coding with information is the traceability of pharmaceuticals and best before information.
Not only in the food and beverage industry best before information must be clearly readable and correct. Additional traceability information like lot numbers is important as well, in case of a bad a product batch with faults and the company has to withdraw the products from the market.
But not only traceability and shelf life are important information for product coding. Also information to the product itself or for further processing is required, like for example in the cable industry meter-marking are printed on cables. Coding products is an important part in any industry branch like automotive, pharmacy, food, beverage, cable, pipe, plastic, electronic and packaging.
Coding systems can mark, label and print on almost all kinds of materials and surfaces.
There are different kinds of coding systems like for example small character inkjet printers . These printers print with the continuous inkjet technology fast and contactless on products or packagings.
Kodiersysteme sind in der Lage fast alle Werkstoffe und Oberflächen zu beschriften, zu bedrucken, zu kennzeichnen oder zu kodieren. Es gibt verschiedene Arten von Kodiersystemen wie zum Beispiel die Kleinschrift-Tintenstrahldrucker aus dem Produktportfolio von LEIBINGER, welche mit Hilfe der Ink-Jet-Technologie für die berührungslose Kennzeichnung von Produkten und Verpackungen eingesetzt werden können.
Marking machines are devices or systems that can label all kinds of products. Among the marking machines you find color marking machines and inkjet printers for non-contact printing of inks. Marking machines label the products automatically by using sensors, sensor barriers or impulse sending switches.
The increase of product fraud and the demand for complete traceability oblige producers of industrial products to mark their products uniquely. But not only each product needs to be marked with special information e.g. lot number, best before date, technical information, graphics or fill quantity. All products, including their packaging, must be marked individually for traceability of the producing process.
Product marking can be done by several kinds of sign technology like laser, engraving, inkjet printer, thermal transfer printer, label printer or stamping.
Laser printing or inkjet printing are the most used marking and coding technology in the industry. Both methods are non-contact systems where form and shape of products are not important. Laser printing needs a product surface which changes its color by heating.
But not all products have a surface that changes its color by heating. For example 2D codes printed by a laser cannot be read by a scanner. Therefore laser printing is not as popular in the complete industrial product marking as the continuous inkjet technology.
In this marking process the fast and non-contact continuous inkjet technology meets all requirements of ink-jet printing within the marking and coding industry. It is necessary that the marking can be done on all carriers. With an inkjet printer all kinds of print information can be done like texts, barcodes, graphics or databases.
Usually the inkjet printer is integrated into the producing process directly at the assembly line. The range of application of product marking systems with inkjet printers reaches from egg printing with food grade inks, printing best before dates on packaging or even marking black cables with white contrast inks. If solvent based inks are used, the print is smudge-proof after one second on glass, plastic or metal.
Text, symbols, barcodes and DataMatrix formats can be printed onto a wide variety of materials in the industry. Modern product marking system use high speed inkjet printers filled with a wide variety of inks rich in contrast and excellent adhesion. In order to avoid product fraud, several industries, for example the pharmaceutical industry , even uses invisible inks.
MEK is the abbriciation for methylethylketon.
MEK inks offer reliable and consistent marking on most surfaces and coatings. They evaporate fastly and have a high content of solid matter. Furthermore they print with exceptional dot sharpness and readability. They are mainly used for plastic, metal and ceramics.
See best before date.
Best before date / expiration date indicates the length of time that food, drink, medicine, chemicals and many other perishable items are given before they are considered unsuitable for sale, use or consumption.
In some regions a shelf life, a best before date, an expiration date, a use-by or a freshness date is required on the packaging of perishable foods or medicine.
Generally speaking, an expiration date is the recommendation of a certain time that products can be stored. During this period the defined quality of a specified proportion of the goods remains acceptable under expected or specified conditions of distribution, storage and display.
The best before date is printed e.g. on the lid of a yoghurt cup, on the side or the bottom of a bottle. It is important that the imprint always can easily be recognized and read and that it remains on the product until the end of the date. Furthermore the ink must be able to be printed on different surfaces, referring to form, material or humidity/temperature at the assembly line.
Nowadays even eggs are imprinted with an expiration date. For this application continuous inkjet printers (CIJ) with food grade inks bring best results. CIJ printers are a non-contact technique with different kinds of inks depending on the product material and imprint. See the LEIBINGER product range of inkjet printers.
The inks reach from dye-based and soft-pigmented inks, fast drying inks, keton free, alcohol and water based inks, pigmented contrast inks, security, color changing, sterilization, adhesive and alcohol resistant inks, food grade inks and food packaging inks. All forms and kinds of surfaces can be imprinted like round, vaulted, waved, rough or graded surfaces.
Pharmaceutical products are liable to strict regulations and guidelines. That’s why special requirements have to meet in marking and coding of product packagings.
Traceability, protection against forgery and legibility
The traceability of the product, but also the protection against forgery or good legibility must be ensured. Packagings of pharmaceutical products e.g. can be marked with the EAN DataMatrix code.
Piezoelectric printers are high-resolution inkjet printers that operate on the basis of continuous inkjet technology or the drop-on-demand process.
They utilize the piezoelectric effect: Piezo crystals located behind a print nozzle are subjected to a voltage. The crystals deform, exert pressure on the colored liquid and direct a color droplet through the nozzle. The strength of the pulse controls the size of the droplet.
In coding and marking technology, piezoelectric printers are frequently used for labeling packaging and coding products as well as addressing and personalization in virtually any area where outstanding typographical quality is required.
Product marking gives sellers and buyers information about the characteristics of the product or the packaging. These could be made by symbols, pictograms, graphics, logos, text or numbers.
Product marking guidelines
Which product in which way has to be marked is defined by several guidelines.
There are numerous ways to mark and code products. Products can be marked with information like the product number (the European Article Number or the Universal Product Code), displayed as bar code as well as a symbol for the filling procedure (a printed e) next to the filling volume. This declares that the product has been filled according to the guidelines of the European prepackaging guidelines.
A CE symbol confirms that the product can be traded within the European Community. Furthermore products are marked with danger symbols, information to the brimfull volume (displayed as framed number which describes the filling volume of a packaging), symbols for materials with food quality or the recycling method.
Depending on the product additional information has to be made from the manufacturer for seller and buyer.
In the European Union are guidelines for cosmetics that cosmetic products have to be marked. This information includes the sell-by date, eat-by date, time of usage after opening, cosmetic ingredients list as well as the lot number, which gives information about the production line during manufacture.
Foods have to be marked with a lot number to inform about the exact production line during manufacture. Furthermore on foods are marks like the treat-capability-mark, which gives information to the route of transport of animal products or the nutrition facts.
Electronic devices need numerous labels for example a GS for certified security, RoHS, TÜV, VDE or UL, PSE, ETSI, FCC etc.
Besides such labels/symbols information to the magnitude and nature of input voltage, maximum voltage and sometimes the power frequency are named. Manufacturer can give additional information to the product with several further test symbols.
Product marking techniques
Product marking can be made with different techniques. Typical product marking techniques are: inkjet marking with small character inkjet printers, laser marking, labeling, colored markings and thermotransfer printing.
Marking with inkjet printers
Marking with inkjet printers, also known as CIJ printers, is mostly done with solvent based ink, which is printed contactless on the product. The generated marking is a so called dot font, because the ink is divided into single dots already in the print head. The desired character is built by charging the ink dots with electric charge and deflect them afterwards more or less depending on the charge.
By the contactless print process all kinds of surfaces can be printed – no matter if round, corrugated or moistly. Also colored markings are possible with the huge amount of inks. See also: LEIBINGER inkjet printers.
In product marking small character means by definition small signs/symbols or graphics up to a certain font height. This description is mostly used in combination with marking instruments for example at small character inkjet printers.
These marking instruments are continuous inkjet printers , which print signs/symbols and graphics with font heights from 0.8 up to 16 mm.
Especially on small products with less space for the product marking, for example best before date, lot number or a barcode, small character inkjet printers are used. Small character inkjet coders generally print information that can be as little as a single line and as many as 5 lines.
For verification and 100% control of printed data such as numbers, barcodes, 2D codes (DataMatrix ), texts, logos, text bodies, high-performance camera control systems are used. Various features can be verified simultaneously and classified. The camera systems can optionally and individually for each application equipped with matrix- or linescan cameras.
The marking of packaging serves the traceability, the logistic handling or the just-in-time-production. Each product in the production line must be marked with for example barcodes, 2D codes, logos and graphics.