Package Integrity Testing
Package testing suppliers share their insights on the latest trends, technologies, and ASTM standards.
|The Alumivision from Micron PharmaWorks inspects for pinholes, cracks, and fractures often caused during the cold forming of aluminum foil.|
Package testing methods and equipment are improving, leading to greater speed and accuracy, thanks to new technologies and ASTM standards that are helping manufacturers deal with the challenges of testing various packaging materials.
The most recent spring ASTM meeting of Committee F02 on Flexible Barrier Materials and Committee D10 on Packaging introduced several new standards and methodologies, and updated some of the older test methods for package integrity testing.
One of the highlights of the meeting, says Stephen Franks, executive vice president, T.M. Electronics Inc. (Boylston, MA), was the completion of round-robin testing performed by six to eight labs for the development of a precision and bias statement for F88, the standard for seal peel testing. ï¿½It was great to have them finish the round-robin testing because it clearly points out to users the differences between the test methods that you choose in F88,ï¿½ he says. ï¿½Itï¿½s information that hasnï¿½t been clear to users, and itï¿½s very clear now when you look at the data.ï¿½
Pat Nolan of DDL (Eden Prairie, MN) agrees. ï¿½Itï¿½s a fantastic study to improve the integrity of that test method,ï¿½ he says. ï¿½If youï¿½re going to compare results from one lab to the next, you need to be sure youï¿½re using the same test method.ï¿½
Other seal-strength testing methods are being updated, says Franks, including F1140, which is commonly used for seal-strength burst testing, and F2054, a test method for burst testing using restraining plates. T.M. Electronicsï¿½ BT-1000 package integrity and seal-strength tester is widely used in the medical device industry in compliance with these test methods.
Another test method that is being worked on is a leak integrity method for porous packaging. The method applies vacuum to a package, explains Nolan. ï¿½If thereï¿½s a leak in the package, the vacuum pressure will change as the atmosphere from the packages leaks into the chamber.ï¿½ Itï¿½s a comparative method, adds Franks, in which you are measuring the differences in vacuum levels.
A committee is being formed to develop a new test method for package integrity involving dye-penetration tests. This methodology is similar to the current method, F1929, says Nolan, but would involve subjecting the seals to a dye from the outside of the package, rather than injecting the dye inside the package. ï¿½Itï¿½s less destructive to the product in the package,ï¿½ he notes, ï¿½ but has the same results.ï¿½
Nondestructive test methods are becoming more popular, say some package testing suppliers. ï¿½When you take a package with the product in it and destroy it, customers would rather have a nondestructive test,ï¿½ says Steve Bunnell, sales and marketing manager for Mocon Inc. (Minneapolis). In January 2004, Mocon acquired a German company, Lippke, and now offers the Lippke VC 1380, a blister leak test system. The tester uses blue dye so leaks can be seen and located; however, the method can also be used without dye, making it
a nondestructive test, explains Bunnell.
Customers are also interested in speeding up the testing process and are going about this in several ways. ï¿½Production-line quality testing used to be dedicated to the QA labs,ï¿½ says Steve Pearson, new product manager for Sure Torque Inc. (Sarasota, FL), a manufacturer of cap torque testers. ï¿½Now, more customers are attempting to conduct testing on the individual lines or on the production floor. Many more customers are trying to integrate the quality control equipment with their computer systems so they can gather the data and respond to it immediately.ï¿½
Jim Head, product manager for Quantrol by Dillon Force Measurement Systems (Fairmont, MN), is also noticing customersï¿½ needs for rapid data acquisition. ï¿½Users want to conduct tests that donï¿½t take a lot of time,ï¿½ he says. Trying to capture a peak that only lasts several milliseconds is becoming more commonplace.ï¿½ Increasing the peak capture rate is one of the focuses of the companyï¿½s force gauges.
Many manufacturers also want the information seamlessly transmitted from the gauge to the application theyï¿½re using, notes Head. ï¿½If theyï¿½re making a report in Microsoft Excel, for example, theyï¿½re looking at ways they can get the data from the gauge into Excel, both for speed and improved accuracy to reduce operator keying or recording errors. We have made a very conscious effort to address these requirements through our high-speed force gauges capturing peak data at 2000 times per second, as well as our software interface tools.ï¿½
John Bolinder, marketing manager/sales for Nelson Labs (Salt Lake City, UT), suggests using a contract lab for package testing if you want to save time. ï¿½Thereï¿½s a benefit because [a contract lab] has seen a million types of packages. If itï¿½s something weï¿½ve seen before, and itï¿½s known to fail or itï¿½s problematic, we can be upfront with the customer and help them through some of the dynamics of design change or consultation. If a customer isnï¿½t using a common product, the best thing to do is consult with a contract lab first. That will save a lot of money and time.ï¿½
|Seal-strength testing in accordance with ASTM F88 can be performed on thermoformed trays with lids using a tensile testing machine.|
Suppliers have also noticed that customers want increased accuracy. Older equipment is being upgraded and incoming materials are being inspectedï¿½not just the finished package. For pinhole-detection systems, Steven Antonacci, president of I.C. Technologies Inc. (DeWitt, NY), is seeing requests for detecting pinholes as small as 10 microns. ï¿½On-line systems for detecting holes in the base material as well as the lid material will ensure a more-comprehensive package test, which otherwise may be diminished by inspecting only the base material,ï¿½ he adds. The challenge, he says, is that the on-line inspection process is limited to presealing, which will not detect problems with the sealing process.
Pete Buczynsky, president of Micron PharmaWorks (Tampa, FL), agrees, saying that inspecting the seal bond between the lid and the base material would be ideal. Currently, the only way to do this is off-line. Micron has the technology; however, Buczynsky notes that ï¿½even if we could apply our technology on-line somewhere after the seal station, the question still arises, how do you know that it didnï¿½t get damaged in the perforation station or in the punch?ï¿½ Space is also an issue. ï¿½The best place would be after itï¿½s punched, but then speed is an issue because products are flying out four times as fast.ï¿½
Micron offers a new Alumivision foil-fracture inspection unit designed to inspect pinholes, cracks, and fractures often caused during the cold forming of aluminum foil materials used in blister packaging. ï¿½We can identify exactly where the defect is,ï¿½ says Buczynsky, which is important for statistical analysis to determine the cause of the defects. ï¿½For example, a high number of defects in one area of the web most likely indicates a defective form tool or plug, which can then be quickly repaired or replaced.ï¿½
Manufacturers need to be aware of several factors that can influence testing results and affect their accuracy. Differing humidity environments, for example, can affect the outcome of your test, says Nelson Labsï¿½ Bolinder. ï¿½We consult with clients about humidity and make them aware of that when they run their tests,ï¿½ he says. The company is looking to place its Instron seal-peel tensile tester in a humidity-controlled environment to mitigate the variables of the test.
DDLï¿½s Nolan also notes that humidity can be a ï¿½secondary stress elementï¿½ when it comes to defining the parameters for accelerated-aging tests. However, ï¿½the ongoing trend seems to be to disregard humidity and just use temperature as the testing parameter,ï¿½ he says. Nelson has also faced the challenge of testing larger packages. ï¿½A lot of medical device companies are putting packages into kits, and these kits turn out to be very large. A lot of them are large thermoformed trays that might contain a device and maybe some drugs,ï¿½ he says. As a result, Nelson has to conduct testing on much larger packages. ï¿½We might get a pouch that is 1 ï¿½ 2 ft in size. Trying to do a package integrity test on that pouch has become a real challenge. The current methodology is to do a water-submersion internal pressure test or bubble emission test, but the challenge is trying to get the package under the water when it is filled with air.ï¿½ Nolan says that new testing methodologies will have to be developed to test these larger packages, or some of the existing methods will have to be modified to accommodate large packages.
Jim Wise, site manager for Westpak (San Jose, CA), also notes the challenges of bubble and dye tests on large packages. ï¿½If you have a big pouch, a lot of people will fold the Tyvek over to minimize the carton size,ï¿½ he explains. ï¿½When you bend it, Tyvek to Tyvek, you put it in a compression mode, and it delaminates in the mid-plane. When you conduct the test, you get what looks like a crease, but itï¿½s delamination.ï¿½ This can result in false readings, says Wise. ï¿½My recommendation would be do not fold Tyvek over, and if you do, fold it over Mylar to Mylar.ï¿½
Wise also suggests that customers consider the sequence of testing. ï¿½Visualize how you are going to distribute your package. Are you a) going to manufacture the product, store it in a warehouse for ï¿½xï¿½ amount of time until the shelf life expires, and then ship it, or b) ship it directly to the customer who will store it. This will determine whether you do transportationï¿½ drop, vibration, and compressionï¿½and temperature and humidity before or after the accelerated aging tests. If you do the aging test first and then the distribution test, you will have to repeat that test several times.ï¿½ The cost can double depending on which sequence of tests you choose, says Wise.
|Carleton Technologiesï¿½ 2800 offers seal-strength and integrity testing for nonporous packages. Mass flow and pressure decay are offered with airtight fixtures for open and closed packages.|
Cost is a real concern for customers, he notes, and many are struggling with the issue of quantity because they have to use representative product. ï¿½They want to know how many they should test to satisfy FDA, and then theyï¿½re balancing that against the cost of doing more testing than they need to.ï¿½
Jim Zynda, sales manager for Test-A-Pack Products, Carlton Technologies Inc. (New York City), also recognizes the importance of controlling equipment costs. ï¿½The medical industry is looking for integrity testing for porous packaging that is under $30,000,ï¿½ he says. The companyï¿½s 2700 test system verifies the integrity of nonporous packages with absolute or gauge pressure testing. It can be conducted as a visual or dye test. Test chambers are available in three sizes depending on customersï¿½ needs. The companyï¿½s 2800-series tester conducts quantitative leak and seal-strength tests on porous and nonporous packages.
ASTM continues to play an important role in approving standards and recognizing new technologies that will help improve package testing. At the Medical Design & Manfucturing (MD&M) Show in New York City in June, Tony Stauffer of Packaging Technologies & Inspection LLC (Tuckahoe, NY) gave a presentation on test methods for seal integrity in medical device packages, including airborne ultrasound (ABUS) inspection, a new technology presented to ASTM. According to Stauffer, ABUS inspection is non-destructive and noninvasive. It allows the user to see defects that manual inspection will not see and determine the exact location of the fault. It is a noncontact system (no wet coupling) and integrates with equipment for 100% on-line inspection.
ï¿½The fact that ASTM is continuing to develop these industry methods and FDA is adopting them as consensus standards is making it more uniform across the industry in terms of how tests are done and how theyï¿½re being looked at in terms of validation requirements,ï¿½ says T.M. Electronicsï¿½ Franks.