Laser, a useful tool.
1. Which type of system provides a more reliable, permanent method for product coding, ink-based or laser-based?
The answer is laser-based. Laser coders rely on intense infrared light to mark product or package surfaces with date and identification codes. The mark formed by a laser is permanent because the light energy either removes a thin layer of material, like the ink on a paper label or carton; etches the surface of materials such as glass; or causes a color change, as in certain plastics. Unlike ink codes, laser codes cannot be rubbed off, smudged off, or washed off. In addition, by using optical imaging techniques that can be compared to those of a slide projector, laser coders consistently provide clear, perfectly positioned marks regardless of line speed variations. Some current laser coding users have reported system uptimes exceeding 99.97%, and missed marks have been measured at less than 10 parts per million in certain demanding applications.
2. Laser coders lack the automation of other non-contact methods such as ink-jet. True or false.
The answer is false. In the past, character changes in typical laser systems meant physically placing new code information--in the form of stencils (masks)--in the path of the light or beam. The evolution of programmable mask modules now allows entry of coding data either locally via an attached keypad or from a remote computer to enable multi-line alphanumeric code changes at high speeds. Multiple coders now can even be networked to allow coordination of code changes at all coding points on a packaging line, or on many lines throughout the entire packaging area. In addition, new dot matrix laser systems, which offer the reliability of lasers and the flexibility of ink-jet coders, are now available. These systems do not require masks for imaging code information; they allow instantaneous programming and code changes from an integral keyboard or host computer.
3. Laser coding systems must be dedicated to a specific application. True or false.
The answer is false. While laser coding systems employing mask technology require rigid framework to support the laser and beam delivery components, these systems can be designed with a surprising amount of flexibility. Since these systems are typically custom-designed, knowing the scope of the required system versatility at the time the system is specified can allow laser suppliers to satisfy most requirements.
Allowing still greater flexibility, the latest generation of dot matrix laser coders provide true point-and-shoot operation. Employing a moveable, articulated arm between the laser and the print head, these systems can be rolled up to the packaging line, pointed at the mark point and commanded to mark the desired code.
Also available are pulsed Nd: YAG laser coders which offer flexible fiber optic beam transmission systems. Fiber optic delivery allows the marking head to be set up separately from the basic unit, enabling users to incorporate the coder onto practically any production line.
4. Laser coders can only mark relatively small characters, true or false.
False. The newest dot matrix laser coders can mark characters as large as 0.6". And they can mark in one-, two-, and three-line formats, albeit at smaller sizes in multi-line styles.
5. Lasers can mark all package or product materials, true or false.
False. While laser coding has come a long way, some materials are difficult to laser code. For instance, high-density polyethylene (HDPE) is not easily marked because it is transparent to the infrared energy produced by the laser. However, new material additives, like the Afflair |R~ Lustre Pigments from EM Industries, Inc., are making coding on previously unmarkable materials a possibility. These pigments can be incorporated into plastics, films, coatings, and other packaging materials to enhance markability. Acting as light receptors, they cause materials to blacken when hit by the laser, creating permanent, clear, high-contrast marks.
6. Laser systems are too expensive for applications which require marking on multiple product lanes. True or false.
False again. Today's laser coders can be configured to cost-effectively meet almost any packaging need. For instance, packagers desiring to mark individual blister pack or flexible pouch units can employ one laser head to mark multiple product lanes. In the past, packagers would need to dedicate one laser coding or inkjet system to each mark point on a packaging line. To avoid the expense associated with employing the multiple coders necessary for this application, packagers opted for the use of barely legible embossing techniques, burdensome flexographic printing, or even settled for only marking the secondary package. New laser scanning techniques, however, allow packagers to utilize one laser to code several lanes of product on both indexing and continuous motion packaging systems.
7. Laser coders always require external cooling water and special gas to operate properly. True or false.
False. Dot matrix laser coders employ sealed C02 lasers, so no external gas supply is required. The latest systems have also eliminated the need for external cooling water by adding an integral water-to-air heat exchanger within the coder. These systems only require electricity from a standard 115 volt outlet and a small supply of compressed air to prevent dust from contaminating the focus lens.
In addition, the last several years have seen improvements in gas utilization by traditional laser coders, and some suppliers of this type of system will provide a stand-alone closed loop cooling system as a part of a complete laser coding solution.
8. Laser coding is an environmentally-friendly coding alternative that provides a safe work atmosphere. True or false.
True. Laser coding systems do not utilize the inks and solvents associated with ink-based systems. Waste and disposal problems are eliminated as well as employee health concerns over long-term exposure to these materials. Plus, removing inks and solvents from the workplace eliminates undesirable odors associated with these materials.
Laser coding may generate some dust and debris in the marking process, but this material can be simply vented. Some laser companies provide low cost vapor extraction systems employing micro-filtration and/or activated carbon to remove this debris in those applications requiring this treatment. Most laser systems provide beam shielding to prevent worker contact with lasers and interlocks to prevent accidental or unsafe firings.
9. Laser coders require specialized maintenance procedures to ensure successful operation. True or false.
True. These systems require occasional optics inspection and cleaning. While not an especially complex procedure, optical maintenance techniques must be learned by users of laser coding equipment. Problems found in the field are actually often the result of the reliability inherent in laser coding technology. While little maintenance is required, this little bit is essential to ensure continuous trouble-free operation. Neglecting the suggested weekly or monthly inspection routines can cause a build-up of debris on the optics that will result in a failure of the component. Correctly cleaning optics when required can often extend the lifetimes of these components for many years.
10. Other non-contact coding methods such as those which rely on ink are more cost-effective than laser coders. True or false.
False. While a typical laser coder requires a larger initial capital investment than other non-contact methods, such as ink-jet coders, laser coders yield a higher return on investment. Laser markers require no inks or solvents and require less cleaning and servicing than ink-coders, thus minimizing expenses for consumable goods, costly routine maintenance and other related costs. For example, the typical annual operating costs for an ink-jet system can range from $4,000 to $12,000, while the typical annual operating cost for a dot matrix laser is around $1,000. Based on these figures, a laser coder purchased at $30,000 becomes more profitable after as little as 16 months of service compared with an ink-jet system purchased at $15,000. In addition, the expected useful lifetime of laser coding equipment is more than twice that of ink-jet coders, further enhancing the cost-effectiveness of the equipment.
(Macklin is a vice president with Laser Technics, which is based in New Mexico. The contact phone is (505) 822-1123).
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|Title Annotation:||Wise & Otherwise|
|Publication:||Wines & Vines|
|Date:||Nov 1, 1993|
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