ELECTRON BEAM PRINTING SOLUTIONS FOR THE LABEL INDUSTRY
Today there are many technologies available for printing variable information, but why has electron beam imaging (formerly called ion deposition) been the most successful in high speed web printing for the tag, ticket and label market? To answer this question and to look at future opportunities, this will cover electron beam imaging (EBI) technology, press integration, its flexibility and successful applications.
Electron beam imaging printing is an off shoot of the toner based technologies which became popular with the bond copiers of the mid 1970’s. In fact, the basic technology was developed as part of a research project on the subject of improving copier performance. There has been a lot of talk in the tag and label market regarding electron beam imaging and who developed it etc. The technology was developed by Dennison Manufacturing Company in the late 1970’s. Since that time the technology expanded into several printing markets including tags, tickets, labels, lottery tickets, form, direct mail and financial statement printing. After the technology was first invented Dennison formed Delphax as a joint venture with Canadian Development Corporation (CDC) to expand the usage of electron beam imaging into the computer output market. CDC then sold its share to Xerox and then later on Olympus became a third partner in Delphax. When Avery merged with Dennison, the Imaging Systems Division of Dennison (engine manufacturer) was sold to Delphax and now Delphax manufacturers and has all the rights to electron beam imaging print engines.
How it works
The electron beam imaging process features a dielectric cylinder which is selectively charged to attract toner in the patterns to be printed. All this is similar to other toner type printing processes, such as electrostatic, magnetographic, and laser printing.
Electron beam imaging printing differs from the other methods in that it uses a stream of electrons to selectively charge the drum. This beam is electrically produced in a device much like a printed circuit board which is called the print cartridge. This contains ports or holes through which the electrons pass when allowed to by the computer which manages the imaging process. As they project down onto the dielectric cylinder, which is rotating below the print cartridge, they fall into the image of a letter, a symbol, or a bar code as directed by the computer. The original work on the process, done in the mid 1970’s, hypothesised that it was actually a stream of ions which charged the drum. This gave rise to the name ‘Ion Deposition’. Through extensive research in the recent years, it was noted that the ions were actually electrons and hence, the name change to electron beam imaging.
Once on the dielectric cylinder, the charge pattern forms a latent image. Nothing can be seen at this point because no toner has been introduced. As the dielectric cylinder rotates, it is close to a supply of toner which is held in place by a magnetic toner cylinder, called the toner brush.
Toner clings to the toner brush because it is attracted by permanent magnets inside the steel cylinder. The force of attraction from the passing electrons is greater than that of the magnets, though, at least for the small area around each electron. This means that toner jumps from the toner brush to the drum and clings by electromagnetic force to the latent image. Non magnetic toner systems for special applications are also in use as part of the technology.
The Dielectric drum then continues its rotation to the point where it meets the moving web of stock which is squeezed between it and an opposing pressure cylinder. This ringer action drives the toner into the substrate and the actual printing occurs.
The printed substrate then exists the print engine to be rewound, plate printed, die cut, or handled in some other way. The dielectric cylinder continues its rotation past a fixed scraper blade which removes the small amount of toner that may have failed to transfer to the web. After this cleaning, the drum passes beneath the ease rod. The erase rod constantly generates an electromagnetic corona which neutralizes any residual charge that might be left on the drum. This process removes the electronic image from the drum and prepares it for the next print charge.
The dielectric cylinder can have all of the various functions of electron beam imaging in progress simultaneously at different points of its rotation. This makes the printing process continuous and allows for high print speeds.
The first question asked after electron beam imaging was invented was, where can it be employed for the future? In the tag and label market the need was and is still very much today, to do variable data on press in one pass. As the market for variable data printing continues to grow, the electron beam imaging engines continue to be mounted on commercial web presses to produce variable data media at very high speeds in one pass.
There have been many different types of press integrations done with numerous presses. In addition, with a web press, the EBI unit can be integrated after the unwind or after a colour station giving you complete flexibility to service major requirements. It is important to note that if the system is mounted after an ink station or ink stations, the inks must be completely dry prior to entering the system so that dielectric cylinder stays dry to accept the charged image.
Included with each EBI system is the printer itself, electronics, which are housed in a nearby cabinet, a job control computer, which enables custom jobs to interface with the electronics and printer, and software. The software utilizes a windows type format which allows the user to create the image and proof on the terminal or office printer prior to running it on press. Today there are many models available for the web printing market. These engines have the capability to print up to 365mm (14.4 inches) wide at speeds up to 91 m/min (200 ft.min). The print resolutions range from 240 dpi to 300 dpi. Engines are also available to print in a two sided mode (duplex printing) with complete synchronization.
To give you an idea of the EBI system capability we should start with the subject of variable data. A lot of people think variable printing is bar codes. It is now important to note that variable data can mean anything that is constantly changing. It can be sequential or random bar codes, sequential or random numbers, changing text such as names/addresses, copy changes, or even letters as you see today in the direct mail market. Changing graphics also represents variable data and we know how important these are on lottery tickets and promotional games.
Focusing on bar codes, the EBI systems have the ability to print all of the major symboligies with different densities. Depending on the bar code application you are printing for, you may need a low or medium density to match the scanning requirements. Again, application driven is the bar code height. This needs to be able to vary to capture reads at the required scan distance and speed if the bar coded objects is moving past a scanner. Check digits can also play an important role in a bar code application and these are also programmable within the EBI platform.
With the EBI systems you also have complete alpha numeric font flexibility with a variety of type styles, different point sizes, the ability to rotate characters, and even mirror image font capability. Heights, type of font, densities, positions can all be varied to meet specific requirements. Depending on how the application functions, alpha numeric font flexibility can become especially important.
Variable data can also include graphics. It is important to point out that you could actually use an EBI system to print different logos, game symbols and other images. With this capability, there is actually a possibility to eliminate copy changes.
In custom printing, the most important capability one can have is the ability to print on a variety of substrates. Again, the industrial EBI systems have been utilized by a variety of printers to print on all major types of pressure sensitive, tag and ticket materials. Some pressure sensitive stocks being successfully printed on include matte litho, high gloss, latex impregnated, EDP, vinyl, polyester and all types of piggyback constructions. Successful tag material has included up to 15 points in thickness, vinyl, kimdura and tyvek.
What is happening within the market in terms of variable data printing, and where can electron beam imaging with all its capability be successful? In today’s competitive world there is a strong need to respond faster with higher quality and lower costs. As part of this demand we have seen Computer Integrated Manufacturing (CIM) and Just In Time (JIT) systems develop to aid manufacturers in getting their products out the door faster with less inventory needed. From a quality standpoint, we have also seen the rise of quality programs being implemented at many manufacturers to help them active total quality.
To achieve these company wide objectives and maintain competitiveness the need for automation has never been more prevalent. Every day more and more companies are spending money to update and create new systems for automation. One of the most widely used tools today is bar coding; a system to get data into a computer faster with virtually zero errors. By bar coding objects whether they are boxes, parts, test tubes, logs or even animals, the accuracy has long ranging effects including faster turnaround, inventory reduction, better service, and improved quality. In this section a few of the many applications that have been done using EBI printed media will be explained so that the opportunities of printing with electron beam imaging will become very clear.
For the last eight to ten years the electron beam imaging printers have been used to print variable data for many markets. In the government, bar code tags and labels have been used at the federal level to track and sort mail as well as animal blood testing. On the state and local level, bar coding has made its way into fishing and hunting licenses. To service customers better and lower sortation costs, the transportation industry has used bar codes. The need for test accuracy prompted the reading and recording of the test tubes via bar codes in the clinical lab arena. With lumber being a commodity with changing values, bar codes have been used to update inventory records and distribution reports. The same types of automation have occurred in the textile, food and beverage, and retail market segments. Let us now look at some of these current applications automate their inventories or expedite the unit tracking process.
In the transportation sector, major trucking companies are looking at automation to help them track their goods more efficiently. Some of these firms have turned towards bar coding. The application involves sequential bar code numbered sets so that each customer shipment can be assigned an unique number for documentation and tracking purposes. As the freight moves from hub to hub it is tracked via bar code scans so that at any one time the location is known and can be communicated to the customer inquiring.
Anyone who knows of someone involved with the tracking of cylinders, chemical drums and even beer kegs knows that there can be a challenging return procedure. Hospital supply, chemical and food and beverage companies are starting to use bar codes to track cylinders since they travel to many locations and they represent a fair amounts of cost. By sequentially bar coding cylinders, companies can now track them much easier. Before they all looked the same and it was difficult to tell them apart. Also, with a unique sequential bar code, updates and records can be kept on each cylinder, such as current location, last servicing, age, conditions, etc. These labels are typically constructed of polyester film and are over laminated with a polyester film to withstand a sometimes physical environment.
As companies automate their warehouses many CIM and JIT programs incorporate the usage of bar codes and these types of labels are becoming very widely used. Physical inventories using these bar coded labels also become a snap and can be done on a much more frequent basis. With this application, the data may be sequential or variable depending on the warehouse set-up. Large human readable characters can also play an important role as one may want to view these labels from a distance. These labels are usually constructed of polyester for long life and durability. Colour coding is also very useful at times for distinguishing warehouse location.
Physical inventories are becoming increasing important to large corporations when accounting for expensive capital assets. By using a sequential or variable bar code number each asset has its own license plate which can associate all accountable information regarding that asset. Again, polyester and vinyl construction is used for durability.
In a warehouse environment, it is critical have cost control and proper accountability during the distribution process. By using sequential bar code labels, pallets can be identified easily and therefore, tracked during the distribution process. Typically with pallet labels a lot of companies are specifying low density bar codes. With the advent of long distant reading equipment, pallets being stacked in multiples can now be read from the floor when the labels are printed with low density bar codes. Large human readable characters are also useful. These labels are usually constructed of a matte litho pressure sensitive since they are only read a few times and then shipped.
These days it becomes critical to track all blood specimens during testing procedures. The best way to automate this is through the use of bar codes where each patient can be assigned a special number for their set of labels. By having a label set with the same number, different tests can be conducted on each patient and the results and tubes can be tracked and linked to that patient. Before bar codes, tube identification and result tracking was done manually. The stock construction for these labels is typically a latex impregnated pressure sensitive for adhesion to tight radius surfaces.
In the area of log exporting, the industry needed a way to uniquely track logs for both inventory valuation and distribution since most logs look alike. By using sequentially numbered bar code tags they have the ability to assign an unique license plate to each log and such data as species, grade, and board feet can now be tracked. During the distribution process the stub from each log is torn off and sent to accounting. From there an automated manifest is generated and the inventory is relieved. These tags are made of a vinylite tag material and are over laminated with a polyester film for protection against outdoor environments.
In the retail industry it is common to have either regional or central distribution centres. At these centres, the goods are first received and then distributed to each of the stores. During this distribution process a lot of the boxes look similar and sequential bar code labels are now being used to improve tracking, reconciliations between stores, and physical inventories. Also, since mailing labels are also needed, some retailers have requested combination labels, whereas both the shipping address and sequential bar code are printed on the same label. By using electron beam imaging a converter can print both types of information electronically thus avoiding a tremendous amount of plates changes – one per store address.
In the fresh food distribution market there is a very short time window to compete against when getting the product out the door. The usage of bar code labels and fixed scanning equipment on conveyor now help expedite the distribution process. In these types of applications or any other fixed scanner environment it is very critical to match up the right symbology, bar code density and height for successful reads. These printing features always need to be flexible when printing bar codes and this is one of the main reasons electron beam imaging technology has been so successful.
In all the applications just explained you will notice the label or tag has become a vital identification vehicle for tracking, sorting or distributing. Because of this situation, the printed media becomes much more value added to the customer. As a matter of fact, you are now in the arena where your media is at the heart of one’s business. Labels are now functional items and not just a decoration. For example, I have seen distribution facilities that have used bar coding to automate their order filling operation and reduce manpower. In these facilities, if the labels don’t read as they travel along the conveyors, the plant would shut down because they don’t have the sufficient staff to do the sorting manually.
The important point here is that when the media becomes functional and truly value added, the converter will find that the gross margins associated with this type of media typically will be double over conventional media. The opportunity, therefore, with electron beam imaging is the growing market need for variable data printing, plus higher gross margins yields for this type of media.
Also, keep in mind that electron beam imaging could also help you save time and money in some instances. Look at what is occurring in the printing market. With your customers focusing on JIT as well as improved customer service programs you will note that your run volumes have decreased and at the same time, for customer variety, your plates changes have increased. To be successful in the future the ability to have quick made readies and fast turn around is critical. You must always contain costs and service the customer.
Today with electron beam imaging you may be able to print information/copy changes that would have necessitated press stoppages and plate changes in the past. In addition, electron beam imaging gives you the ability to print this variable data at speeds you are accustomed to so it truly does add up to cost savings.
The business trend of needing more flexibility and better quality at lower prices is not going to go away. The presence of EBI to meet this challenge will not go away either. EBI will be pushed further through research for higher resolution, wider print widths, faster speeds and further development of colour. There are active development programs in place to reach these objectives soon so that EBI remains a strong technology for tomorrow’s printing requirements.