Material Testing

Ralph Young, my famous AICC counterpart serving the corrugated membership, and I recently co-hosted a webinar, aptly named Material Testing and Why You Need It Now! This subject has resonated with both of us for many years now, as more and more of our strategic raw materials are being sourced offshore, with little to no knowledge of exactly what waste papers, chemicals, and compounds are being used to manufacture them. This is precisely why we felt it was imperative to remind all AICC members that there are certain tests that should be performed in-house to ensure that all customers are receiving a product that will meet their manufacturing production-line criteria. For the purpose of this article, I will refrain from any graphic testing devices and comment only on the key attributes regarding functional performance-testing equipment criteria. The purpose is to advise members of what testing I consider to be the most critical today. My top 10 tests are noted below in no particular order.

1. Sutherland Rub Test
   • This test specifically identifies the ability of the substrate, inks, and coatings to withstand transit and handling.
   • The test can also be utilized to determine your best approach to meet your customer’s filling-line demands as well as storage and refrigerated/frozen case concerns.
2. Score Bend Test
   • This testing can afford you, the carton manufacturer, the peace of mind of knowing that you have properly scored the material to provide for the best possible cartoning outcome.
   • The data provided can allow for direct comparisons, as you need to compare and contrast various materials as substitutions become inevitable with continued supply chain woes.
3. Opening Force Test
   • The force required to open a side-seam glued folding carton will be somewhat directly proportional to the score bend test above, as well as the degree of folded score pre-break that is set up on your gluing lines.
   • The style of the carton blanks, along with your gluing parallel score pressure wheels, can be tremendous aids and can allow you to provide your customers with easy-opening cartons for extended periods of time.
4. Slip Angle/Coefficient of Friction Test
   • This inclined plane device will afford you the opportunity to gauge how effectively you have applied the coating to the carton surface—and how well you have cured it.
   • This test is critical to ensuring good carton filling-line performance and should be set up using data established from well-running carton blanks.
5. Dyne Test
   • This test is usually prescribed for more nonporous materials, such as plastics and other nonwoven materials. I have found it to be particularly useful to test incoming lots of papers and paperboards to determine their specific “holdout” characteristics.
   • The data obtained can be cross-referenced with the slip angle, glue seam tensile pull, and gloss testing to tell a full story about that lot of material.
6. Glue Seam Test
   • This test is usually performed in a tensile pull device and gauges the force required to delaminate either the glue strip from the paperboard or the paperboard itself—weakest bond loses.
   • Folding cartons that are packaged heavily or tend to light caliper and “football” around the middle can succumb to a weakened glue bond or too thin an adhesive glue line. This device also can easily compare and contrast various adhesives (hot melt, cold dextrin, cold resin, etc.).
7. Cady Gauge Caliper Test
   • The use of a calibrated micrometer is essential to good carton-making. It should have a minimum of a 1-foot-diameter piston and preferably be motorized to eliminate any heavy-handed device operation.
   • A deep-throated Cady gauge will also allow the checking of folded score parallel to ensure that your carton will stack and pack well, as well as function on the customer’s filling lines. The three most critical measures are near score, far score, and the glue seam. The glue seam sets the bar, and then the far score should match that number, with the near score (closest to the glue seam) set at or below by 0.001–0.002 to ensure proper stack height is maintained in the customer’s cartoner hopper/feeder magazine.
8. Perforation Puncture Test
   • This test is often executed using a motorized Chatillon force gauge mounted to a fixture with an appropriate fixture on the end, sized to replicate the perforated tab desired for testing. It will create a data point when testing a properly functioning tear tab to ensure reliability both from run to run and during a run of folding cartons.
   • The need to maintain a properly functioning tear tab across multiple die positions on a folding carton tool set dictates the use of such a device to quantify results for GMP.
9. Light Box Test
   • A light box, used to see exactly how well perforations and cut scores are being manufactured, is a useful tool that I have at the press side on the die cutter or in-line web press.
   • This gives the operator a quick visual reference to compare die positions once again and gauge the cutting-rule effectiveness. A dull perforation rule is very easily noticed with light penetration before it may be felt in the typical carton checks of each die position.
10. Gloss Meter
    • As mentioned above, this is a print quality device for certain. It is also a measure of the material itself as far as ink and coating holdout is concerned. With the multitude of raw materials we are using these days, I encourage all to utilize the gloss meter instrument to properly document gloss measurements during and between runs.
    • Over a period of time and across multiple materials, you may begin to see patterns you both do and do not care for. Either way, you will be informed and armed to do battle.

Tom Weber is president of WeberSource LLC and is AICC’s folding carton and rigid box technical advisor. Contact Tom directly at asktom@aiccbox.org.