There is an increased awareness about the importance of package integrity across many industries, and with the scrutiny heightening on ours, the pressure is on to invest in better quality inspection technologies that can be applied for both off-line testing and in-line automated inspection. Companies that keep using destructive test methods that were developed and approved for use decades ago should re-evaluate their process and investigate technologies that provide valuable data that will improve manufacturing processes, helping reduce overall costs.
Consistency and reliability
According to Tony Stauffer, president of Packaging Technologies and Inspection LLC (PTI), packaging testing has changed over the past decade by becoming simpler, more cost effective and efficient. Most important is the fact that package integrity testing has become more reliable, thanks in part to high precision non-destructive inspection technologies coupled with a user-friendly approach.
There is a growing need for the development of rapid, non-destructive, non-invasive testing technologies. Some of the non-destructive test methods that address this are:
- Vacuum/ pressure decay;
- Airborne ultrasound inspection; and
- Force load testing.
These methods are not only reliable, but yield repeatable, quantifiable statistical test data. Because they are non-destructive, the same samples can be repeatedly tested, a greater number of samples can be tested and even the actual market product itself can be tested.
Other methods, like water bath, dye tests, and peel and burst tests, are simple to perform and require less expensive equipment, but are destructive to both package and product. These tests also produce test results that are dependent on technique, sample preparation and operator variability, making them more time consuming in the end. Not to mention results from peel and burst tests can be difficult to interpret or correlate to manufacturing process parameters, package quality or shelf-life performance.
Detection and inspection
According to Mettler-Toledo Safeline, processors and packagers in the petfood industry face certain unique challenges, including detecting contaminants, detecting damaged or missing products and identifying overfill and underfill. A presentation about x-ray technology and how it addresses these concerns is available for download at www.mt.com/xraytechnology. The presentation, entitled X-ray Inspection The Future of Packaging Inspection , explains the technology and its specific application to our industry, as well as demonstrates that x-ray provides capabilities not available in metal detectors or vision systems.
Checking for seal integrity using Seal-Scan, an airborne ultrasonic inspection technology from PTI, is a fast, efficient, non-destructive method to verify seal quality and pinpoint type, size and location of seal defects, according to the company. The inspection technology is also capable of testing many different types of packaging materials, such as aluminum, foil, paper or a combination of materials.
Integrated packaging solutions
Doboy Inc., a division of Bosch Packaging Technology, offers the TFT Bag Sealer for woven polypropylene bags. The TFT Sealer trims, folds and tapes woven polypropylene bagging material to provide a sturdy, durable seal, yet is easy to open, according to the company.
The double fold closure features a fold depth of 1.25 inches secured with 2 inch wide case sealing. The double fold tape is resistant to both hot and cold temperatures, and the sealing method provides a sift-proof closure to prevent leakage during shipping and storage. With a high speed of 150 feet per minute, the TFT unit is suited for automatic feeding and is easily integrated into most high speed automatic bagging lines, Doboy says.
A packaging line that emphasizes integrated packaging solutions and a "one-stop-shop" approach is also available from Doboy. The packaging line consists of three machines: the Cobra Carton Former, the Linium 301 Horizontal Flow Wrapper and the Presto Top Loader.
Products on the packaging line are wrapped by the Linium 301 Flow Wrapper, which uses flat wound roll stock film and creates a fin seal, crimped-end wrapper. The Cobra Carton Former offers flexibility with hot melt, lock or simplex carton style forming on a small footprint. The Top Loader collates wrapped products being fed from the Linium 301 and places them in formed cartons for the Cobra.
Cross directional laser technology is another way to keep the good things in and the bad things out. LaserTear cross machine directional (CMD) scoring technology from Alcan Packaging can improve petfood processing with easy-open convenience, superior appearance and tamper evidence, according to the company.
CMD laser-scored film works with zipper applications and creates a unique, "hooded" package that allows for the removal of the entire package header to expose the resealable feature.
By scoring below the zipper, this innovation delivers easier consumer access and eliminates the potential for contents to collect between the zipper and the package. Compatible with vertical form/fill/seal equipment, Alcan Packaging's film featuring LaserTear CMD scoring exhibits excellent machinability, running at top speeds and meeting operational demands, the company says.
Packaging for bulk shipments comes with its own distinctive problems. EDL Packaging Engineer's Unit Load Systems enclose bulk, variable sized or palletized products for shipment. Translucent low density polyethylene film provides both product and handling point visibility during transit, at a lower price than corrugated based packaging. The opaque film also protects from ultrviolet radiation exposure during periods of outdoor storage, according to EDL.