Featured Stories
-
-
Back to the Beach: Global Pouch Forum 2024
The Global Pouch Forum1, produced by Packaging Strategies2, now in its 27th year, is the longest-running flexible packaging event in the... -
Innovation in Extrusion Barriers Can Reduce Brand Owners’ Dependence on Plastic
According to the most recent statistics from the Environmental Protection Agency1, in 2018 the U.S. produced 35 million tons of plastics, while...
News | New Products
-
New COF Indicator Simplifies Measuring Friction on Packaging Film
Tentoma, the manufacturer of RoRo StretchPack® machines has introduced the COF indicator ST 1.0 tool to estimate if the coefficient of friction (COF) on the packaging film meets your requirements.
-
EMT International Builds Customized Punch and Perfing Finishing Solution for Heeter
EMT International, a leading supplier of finishing equipment to the digital print, label and packaging industries announces a new customer installation
-
Double E Group Releases the Schlumpf Powered Core Plug Handler for the Tissue Industry
Feature-Packed Core Plug Handler Increases Safety and Productivity
-
ProMach’s ID Technology Acquires Etiflex, a Leading Producer of Pressure-Sensitive Labels, Tickets, and RFID Labels in Mexico
ProMach, a worldwide leader in processing and packaging machinery and related solutions, announced today that it has acquired Etiflex
-
Re S.p.A. Celebrates 50 Years of Innovation at Drupa
Re S.p.A., an innovative leader in the printing and packaging industry, is excited to announce its participation in the next edition of Drupa
-
Sandon Global to bring anilox excellence and technical know-how to drupa 2024
Sandon Global, the British anilox manufacturer and drupa 2024 exhibitor, is poised to showcase its extensive technical expertise in flexographic printing
-
TIPA Compostable Packaging Appoints John Wilson as Commercial Director for North America
Packaging and sustainability industry veteran joins TIPA, to drive US adoption of compostable packaging to curb plastic waste
Expert Advice
New Inks Have a High IQ
- Published: August 31, 2004, By Dr. Richard M. Podhajny, Ph.D. Contributing Editor
Well, we've heard a lot about “smart packaging,” so it was inevitable such packaging would require “intelligent inks.”
With current packaging development focused on smart and active packaging, some critical R&D is being devoted to inks that can provide real-time information as to the package condition.
Conventional inks are used to provide the customer with brand identification, information about the packaging contents, UPC symbols, and advertising. Although this is vital to selling the package, the packaging designers of tomorrow are putting greater emphasis on providing more information about the package condition.
So, it's no surprise inks are being developed that can be used to provide a visual inspection as to the package contents and the package freshness. This can include information about temperature, level of oxygen, ammonia, and/or carbon dioxide. These sensor-type inks can be referred to as “intelligent inks.”
Many materials change color when subjected to heat, light, pressure, or electrical current. Photochromics change color when exposed to a specific wavelength of light. They are useful in security applications as well as monitors for UV exposure. Thermochromics change color as temperature changes and are used in medical and packaging applications. Electrochromics can change color when exposed to electrical currents or high pressure.
In the mid 1970s, Pilot Ink Co. of Japan introduced Metamo Inks, which utilized thermochromic polymers. Although the products worked, low market demand and product limitations dampened their commercial application in the US.
More recently, polymeric thermochromic materials have been developed at the Univ. of Rhode Island. Such materials have advantages in food packaging applications since they are not migratory. These thermochromic polymers could be incorporated into inks as well as into package substrates.
Conductive inks that can provide product identity using radio frequency identification (RFID) technology are examples of a development that focuses on product integrity and freshness. These inks can be formulated based on conductive silver or silver materials as well as highly conductive carbon blacks.
So, what's new in “intelligent inks”? For many years packaging research engineers have been trying to develop a colormetric indicator that could provide specific information about food packaging and its environment. Recent advances suggest inks that can sense (change color in) the presence of select gases may be available in the near term. Ideally, these would be able to detect the presence or level of oxygen, ammonia, and carbon dioxide. Such inks would be incorporated into the interior of the package and would require FDA status if used for food packaging. Color-changing reactions can take place with the ink providing an indication of the presence of the gas in question in the package headspace.
Inks that are sensitive to oxygen can take different forms. One such approach recently was described by the Univ. of Strathclyde, Glasgow, Scotland. A photoconductor (titanium dioxide) is used in the ink, which when activated by UV light, interacts with oxygen. The presence of an appropriate electron donor, redox-indicator dye, and encapsulated polymer can produce color indicative of oxygen's presence.
Also being investigated are inks that will detect ammonia and carbon dioxide. This R&D has spun off a commercial venture, Gas Sensor Solutions, Dublin, Ireland, which is making these inks available in the form of jet inks and conventional screen printing inks, and claims to be able to monitor oxygen as well as carbon dioxide. Applications include food, pharmaceutical, and medical packaging. Ink formulations allow chemical reactions to take place on the interior of the package, providing a chromatic show of the presence of one or more of these gases in the headspace of the package interior.
Are we there yet? If not, we are getting close. These developments are mapping new chemical methods to formulate “intelligent inks” that can provide a chromatic indicator to sense when the package interior provides — or doesn't provide — a suitable freshness. The above R&D examples are clearly the future of “intelligent inks.”
Dr. Richard M. Podhajny has been in the packaging and printing industry for more than 30 years. Contact him at 267/695-7717; This email address is being protected from spambots. You need JavaScript enabled to view it..