the PLACE

Published: October 01, 2007, By David J. Bentley, Jr., Editor

EXECUTIVE SUMMARY

Transinformative Thermographic Barcode Matrix That Archivally Monitors The Safety Of Food, Drug, & Biologicals: A Fungible Line Item & Carton TTI Sentinel System by Brett l. Lucht, University of Rhode Island, and Robert Goldsmith, SIRA Technologies

APPLICATION: A barcode “data-in-data-out” paradigm can evolve into a transinformative mechanism by using recently developed thermographic printing ink. One such barcode can transforming the message of all other UPC codes.

Universal Product Codes (UPC) barcodes are quintessential for food packaging and are legislatively mandated to soon appear on drugs and pharmaceuticals. Data acquired from barcode readers is the greatest necessary source of information used to conduct our commercial and societal affairs.

The safety and quality of many food and pharmaceutical products is highly dependent upon the thermal history of the products. Products stored at the appropriate temperature during production, storage, and distribution have shelf lives corresponding to the expiration dates. When products are not stored at the appropriate temperatures, the expiration dates become meaningless. The USDA has estimated that 73% of food microbial contamination is the result of improper preparation and holding temperatures. Comprehensive monitoring of the temperature of food and pharmaceutical products from production to consumption is therefore critical for maintaining safety and quality.

While time temperature indicator (TTI) tags have been used for this process, currently available TTIs are expensive and have significant limitations. Current TTIs are derived from one of three types of materials: the time-dependent diffusion of dyed fatty esters through porous material, controlled enzymatic hydrolysis of lipids, and solid state polymerization of uncolored acetylenic monomers that produce highly colored polymers. TTIs are designed as retrievable sensors of the shelf life of products and provide a good correlation to microbial growth, but the cost of TTIs is high and the irreversible colorants cannot be readily incorporated into inks.

A new Universal Product Code (UPC) barcode allows archiving and transforming messages to indicate thermal stress. This technology is enabled by a double barcode matrix consisting of a standard UPC barcode and a monitoring barcode that when activated will transform the normal product data into an automated food safety alert.

Low Extractable, Low Odor, Energy Curable Products For Food Packaging Applications by JoAnn Arceneaux et al., Cytec Specialty Chemicals

APPLICATION: Food packaging applications have shown a sustained interest in and use of energy curable technology in inks and coatings due to the many beneficial aspects in productivity, performance, and ecology.

Due to the numerous advantages (high gloss, excellent resistance properties, high printing speed, immediate further processing, zero or low VOC, and low system cost) provided over other technologies, energy curing technologies have already made significant inroads into non-food packaging applications. The penetration of energy curing technologies into food packaging applications is generally still limited to offset inks and overprint varnishes (OPVs). Very limited penetration has occurred in the fast growing flexographic food packaging ink segment. The constraints preventing full penetration into food packaging applications are the potential for odor and taste transfer, the potential for migration of existing raw materials, the lack of a cost-effective migration testing protocol, the poor adhesion to uncoated polyolefins, and the limited availability of UV equipment for wide web printing. Raw material suppliers and ink makers have until now primarily focused on solving odor and taste issues. The future tightening of food contact regulations especially in Europe will oblige them to consider more thoroughly impurity profiles and migration levels.

Following an approach discussed in the paper, five low extractable/low odor resins are now available. These include a trifunctional acrylate diluent having performance characteristics similar to ethoxylated trimethylolpropane triacrylate but with significantly improved odor-release and migration properties and a low viscosity amine-modified polyether acrylate.

A new range of products specifically designed for indirect food contact applications is now available. These products will help ink makers formulate inks and varnishes for food packaging that meet the most stringent legal requirements regarding organoleptic properties and migration levels. Methods to determine odor and migration of inks and varnishes have also been developed to assist in the evaluation of these food packaging products.

Bimodal mLLD — New Specialty Polythylene For Extrusion Coating by Erkki Laiho et al., Borrealis Polymers Oy

APPLICATION: Using bimodal technology allows production of linear polymers that behave almost like normal LDPE in coating lines.

The unique attributes of linear structured metallocene catalyst polyethylene materials are well known. In extrusion coating, their use has not been as fast as in other applications. The limited growth relates to the linear structure of mLLDs. This work evaluated different metallocene LLDs and a conventional LDPE.

For many years, people have discussed the properties of linear low-density polyethylene (LLDPE) and how to use these benefits in extrusion coating. Compared with basic low-density polyethylene (LDPE), the linear type of polyethylene provides several improvements for end-products including better mechanical and heat sealing properties and improved environmental stress crack resistance. The actual use of these polyethylenes has been small. One main obstacle to the increasing use of LLDPE in extrusion coating applications has been processing difficulties. The primary reason is that linear polymers do not have the same strain hardening and shear thinning phenomena that highly branched LDPE exhibits. Although resin suppliers have worked hard to overcome these drawbacks by adding long chain branching to the structure for example, the growth of LLDPE for extrusion coating remains low.

Based on the advantageous properties of mLLDPE, linear polyethylenes are finally expanding their use into the coating arena. This study examines different mLLDPE and LDPE. The results show that some end-use properties are very good. As a result, linear polymers and especially bimodal ones will change the polymer consumption use in the field of extrusion coating. The work examined three different extrusion coating mLLDPEs and one LDPE. To overcome processing difficulties of the metallocene grades, conventional highly branched LDPE has been compounded in all cases into the linear polymers. One metallocene grade was produced by using bimodal process technology. It behaved very closely to normal LDPE in the coating process. All three mLLDPEs showed excellent heat sealing properties. Especially improved hot tack and low heat seal initiation temperatures are properties that indicate an interesting future for the new coating resins. One major advantage is the possibility to achieve source reduction with these materials from the enhanced heat sealing properties they offer.

The bimodality of mLLDPE facilities its processing and also improves heat sealing behavior. Heat seal performance showed much better values than one would expect from its density.

Troubleshooting The Film Extrusion Process: The Principles Involved by George W. Ealer, Polyfect, Inc.

APPLICATION: Although equipment design and resin grades used in the film extrusion process may change, the basic principles that govern their interactions are the same considerations that allow troubleshooting of problems that arise.

Troubleshooting the problems associated with the process of film extrusion and the products produced in that process has been covered in many formats. Many publications by resin companies present step-by-step techniques and listings that categorize and suggest ways to “solve” the common problems that might occur. These are readily available. The approaches are very helpful to the novice and expert alike because they are the result of experience. Unfortunately, this sometimes results in a fix without a fundamental understanding of the root causes involved. This can lead to future repeated failures or can result in missing a way to find an improved operation or a better end product.

A common and realistic feeling in an actual operation that one experiences during an actual problem is the desire for a quick fix. This is not troubleshooting. Troubleshooting in this paper is any activity taken to correct an unacceptable defect in the film extrusion process itself or in a film extruded or co-extruded using that process where polyethylene is a component resin. Ideally, the desirable troubleshooting process should incorporate basic steps such as planning, testing, problem identification, proposed solutions, etc.

The focus in this paper will be to enumerate the basic elements that require understanding and examination for relevance. It will also suggest ways to approach, evaluate, and understand each one. When appropriate, the paper includes examples from actual situations. During troubleshooting, one may not have the luxury of the amount of time suggested here, but the items should be helpful as a guide for a compressed run plan.

Safety in the troubleshooting process is the primary consideration. Usually some changes will occur during the process of troubleshooting. The safety of people and equipment must be a conscious and careful consideration before making any such changes whatsoever. Note also that the vocabulary of a troubleshooter should not contain two words — never and always!

Good troubleshooting skills certainly require knowledge, experience, focused thinking, and a bulldog-like approach to the task at hand. Nevertheless, the key elements are curiosity and a willingness to share the credit for a task that a person cannot perform in a vacuum. A troubleshooter must question, question again, and question a third time without offending until he uncovers all possible information about the task and problem at hand. The troubleshooter must also record all critical information in a manner that makes it easily retrievable. In some cases, the use of off-site facilities that specialize in running technical trials may be necessary for proper problem solving.

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