| [dfx/incl/99dfx.htm]
Packaging Update: Toy Surprise Inside! New Design Toys include White Light Sensors, Invisible Ink and Synergistic Coatings by Frances Richards Even in the world of nostalgic childhood snacks, the only constant is change. When the Frito-Lay Company acquired Cracker Jack from Borden Foods in 1997, they converted the product container from a box to a bag. With nearly 10 tons of popcorn popped daily for the Cracker Jack operation, the switch from box to bag was handled with a successful transition in packaging machinery. And, though you won't find a toy ring inside this issue, such as the Cracker Jack engagement ring from George Peppard to Audrey Hepburn in "Breakfast at Tiffany's," you may find a real gem for your packaging designs. White LED light source enhances sensors For sensing registration marks on form, fill and seal machines, a white light emitting diode (LED) light source will detect the widest variety of colored registration marks printed on today's intricate packaging materials. White light enhances performance when detecting even the most difficult color combinations, including dark colored marks on dark colored backgrounds. The key advantage of using a white light source, as opposed to red, blue, green or infrared, is that white light is able to best detect color dissimilarity and it allows for the broadest color spectrum in registration marks. The Colormark Smarteye Mark II from Tri-Tronics Company, Inc., Tampa, FL, which uses a white light source, also includes a high gain amplifier and unique 10 LED contrast indicator. These are capable of sensing differences in the color of objects introduced into the light beam path. The resulting signal level deviation is then amplified to a useful level and displayed on the contrast indicator, which provides an instantaneous real time indication of the received light intensity at any range. The reliability of photoelectric "eyes" or "sensors" took a giant leap forward in the early 1970s when the light emitting diode (LED) replaced the fragile incandescent light source. The solid-state light source enables designers to eliminate problems previously caused by ambient room light. Modern pulse-modulated photoelectric sensors respond only to the light emitted by their own light source. This capability allows the sensor to be highly sensitive and responsive to small light changes that occur to the light beam path between the source lens and the receiving lens. For an object to be detected, it must affect the intensity of the light beam reaching the sensor's light detector in one of two ways -- the object must break or diminish an existing light beam path between the source lens and receiver lens (beam break mode), or the object itself must diffuse or reflect the light beam to the receiving lens (beam make mode). The amount of difference or deviation of the light beam's intensity in its lightest state condition vs. the intensity of the received light beam in its darkest state is known as "contrast." The sensing task of any digital switching photoelectric sensor is to respond to and resolve the difference between the contrasting light levels and to switch its output accordingly. These contrasting light levels define the degree of difficulty of the sensing task. Light source options Sensor using white LED light source The five major LED light source options each have unique characteristics. * White : visible white light Best choice for detecting all printed registration marks on packaging material Recommended for detecting dark colored objects in the proximity (beam make) mode Best choice for sortation of colored objects * Red: (660nm) visible red light Best choice for use with plastic fiber-optic light guides Useful when sensing translucent objects in the proximity mode Useful when sensing transparent objects with fiber optics(bifurcated) in the retroreflective mode * Blue: (480nm) visible blue light Performs accurately for many difficult color mark combinations,including yellow-against-white and white labels on cardboard Best choice for detecting translucent or transparent, plastic or glass objects in the retroreflective mode * Green: (550nm) visible green light Typically used with wide variety of registration mark applications Useful in resolving red/pink objects from light colored backgrounds * Infrared : (880nm) invisible light Best choice in most opaque sensing tasks Provides longest possible sensing range in either beam make or break sensing modes Best choice in hostile environments; useful in penetrating lens contamination For more information, contact Tri-Tronics Company, Inc., PO Box 25135, Tampa, FL 33622. 800-237-0946. http://www.ttco.com Circle 512. Clearly marked with invisible ink Invisible marking technology enhances use of valuable label space Remember playing with invisible ink when you were a kid? Thanks to significant developments in near-infrared (near-IR) fluorophore technology, invisible marking systems are fast becoming the new toys of design engineers in the fields of packaging, printing, publishing, sorting, automated manufacturing assembly, robotics and more. The near-IR region of the electromagnetic spectrum exists in wavelengths between 700 and 1100nm. The primary advantage of the near-IR region is its relative absence of interferences as opposed to UV and visible regions. Fluorescence is the process whereby light is absorbed by a substance called a fluorophore at one wavelength, but re-emitted at a longer wavelength. Fluorescence and absorbance are as different as night and day, and measuring fluorescence is 1,000 times more sensitive than measuring absorbance. Measuring fluorescence is described as similar to trying to see the stars at night, while absorbance measurement is like trying to see them during the day. Near-IR fluorescence systems combine the low-interference characteristics of the near-IR region with the extreme sensitivity of fluorescence. When near-IR fluorophores are added as markers to materials or products, these advantages work together, making it possible to reliably detect very small quantities (parts per million or billion) of the near-IR fluorophore markers. Detectors and sensors that take advantage of the increased sensitivity of near-IR fluorescence operate more reliably and efficiently than other detection devices. Eastman Chemical Company, Kingsport, TN, has developed stable compositions of ClirCode invisible markers incorporating near-IR fluorescent compounds. Near-IR fluorescence detection enables the use of such small levels of markers that they are invisible to the human eye. These markers can be used at extremely low concentrations, so that the addition of markers does not affect the properties of the ink/coating medium to which they are added. The markers can be made compatible with a variety of common ink/coating materials, including water, oils, waxes, alcohols, esters and other organic solvents. In addition, the markers can be provided as powders, suspensions, liquid dispersions, solutions or other forms, and can be incorporated into a wide variety of formulated inks and coatings, such as ink jet, bubble jet, letterpress, Litho, UV-cured, thermal transfer and more. Substrates such as paper, plastic, metal, rubber, fabric, film, wood, concrete and laminates all are appropriate for the application of invisible markers. ClirCode markers also provide optimized detectability on backgrounds with varying color densities and may be used to print over existing text or graphics, thereby increasing information density on packages and printed materials.The markers may be used with modified versions of available detectors/scanners, including hand-held, fixed-base, video imaging, yes/no, 1-D bar code and 2-D symbology, at high levels of speed and accuracy. Potential ink and coating applications include:
For more information, contact Eastman Chemical Company, PO Box 431,
Kingsport, TN 37662-5280. 800-327-8626. http://www.eastman.com/prod/clircode
High-tech coatings enhance packaging equipment performance Packaging engineers face a wide variety of challenges when it comes to maintenance and
operation of the broad spectrum of machinery counted on to perform such tasks as wrapping,
sealing, cutting, forming, pouching, blister packing, folding, strapping, trimming and
conveying. Some of those problems include the following:
One of the potential solutions to these problems involves the use of "synergistic" surface coatings which enhance the efficiency and performance of packaging equipment. General Magnaplate Corporation, Linden, NJ, is using these coatings to solve specific problems for a wide variety of very diverse companies. Magnaplate-applied coatings are impregnated into the substrate of packaging machinery component metal parts through a series of proprietary steps that include an infusion of selected engineered polymers. Unlike "paint-ons," these coatings become an integral part of the base metal and won't chip, flake, peel or rub off. They are called "synergistic" because the resulting surface is superior in performance to the base metal or any of the individual coating components. In addition, many of the coatings are USDA-approved and FDA-compliant, making them appropriate for food contact surfaces on packaging machinery. For example, the Ivers Lee Division of Becton Dickinson and Company specified Magnaplate coatings when manufacturing its Utilipak Machine, the BHF. The forming rolls, which vacuum-shape that passing web of film to create "pockets" and heat-seal the web to a second sheet of film to form blister packages, are coated to prevent pick-up of freshly printed ink on the passing film.The throat of the machine also is coated. This is where aspirin and similar products are conveyed from the twin round hoppers at the top of the web of film in which they are to be sealed. Coating the throat prevents accumulation of dust from the motion of the tablets and also prevents marking of the tablets, which would occur if they were exposed directly to the metal. For more information, contact General Magnaplate Corp, 1331 Route 1, Linden, NJ 07036. 800-852-3301. http://www.magnaplate.com Circle 516. [dfx/incl/99dfx.htm] |
