If your lab is planning to subscribe to the Containerboard Interlaboratory Testing Program you may have questions about how the program works. This How To guide for Containerboard Labs is designed to answer your questions.

CTS offers a wide variety of tests for linerboard and medium, box compression and corrugated board. Please visit our Catalogue to familiarize yourself with the tests offered. You may select any combination of tests that are appropriate for your company.

The Containerboard Program materials come from actual mill production. CTS works with industry suppliers to obtain a narrow, uniform roll of linerboard or medium, from the middle of the reel. This helps to minimize cross machine variation. The roll is then sheeted for use in the Program. Because there is still machine variation in the these sheets, CTS randomizes the sheets to distribute the variation evenly. This is done using a mechanical collator and a time-tested, prime number algorithm. The samples are pre-conditioned and packaged in moisture proof mil-speck barrier bags. If your laboratory is unable to condition samples you may test them immediately after opening the mil-speck bag. Corrugated board and boxes are selected and randomized in a similar manner. Due to the size of the boxes, they are not pre-conditioned.
It is important to note the materials that are used for each test. Please click here to see the Material Chart that lists what materials are used in Containerboard tests.

The sample package you receive contains test samples, Specific Test Instructions and data reporting sheets on which testing results are sent to CTS. Please note, the Specific Test Instructions are sent only for the first testing cycle of the year. Your lab should keep the instructions for reference in further test cycles. A downloadable copy of Specific Test Instructions is available by clicking on the link located on the lefthand toolbar, located on any Containerboard web page.

Now, that you know what you will be receiving, you may need to know when the testing is done and samples are shipped. The Containerboard Program works on a monthly schedule. Sample packages are shipped to participating laboratories two weeks prior to the start of each month. Four weeks of testing is conducted each month in the Weekly Program. The monthly Program requires one set of results each months. All testing results must be submitted to CTS by the Data Due Date for inclusion in the report. The Data Due Date is typically the first Monday after the month. CTS will issue a report within three weeks of the Data Due Date. Click here to view the Containerboard Program Schedule.

Test results can be sent to CTS via ground mail or fax (toll free in the United States). For weekly tests we encouraging you to submit data as you go, but no later than the Data Due Date shown on the data sheet. We cannot accept data via e-mail.

Our data analysis includes calculation of the individual laboratory means for each week of the month, each lab’s statistical data for the month (mean, within-lab standard deviation and standard deviation between weeks), and each lab’s cumulative data for up to 16 weeks. Click here to learn how CTS analyzes Containerboard data.

Following completion of the data analysis, CTS prepares and sends to you an individualized Performance Analysis Report. Everything within each report is tailored specifically to your lab, including the data and charts. These the reports are customized for your lab, all reports are single two-sided page for each test, this makes your results easy to review. You can view a sample of the Individual Report sent to participants in the Containerboard Interlaboratory Testing Program.

We also publish a Web Summary Report that allows labs to view the results for all participants in a test. The Web Summary Report is posted on the CTS Web site at the same time that the Performance Analysis Report for that cycle is mailed. To use these results you may need more information on material performance in past cycles. You can visit the Containerboard Report Archive section to track results starting from February 2003.

For those companies that have multiple locations and several labs participating in the CTS Containerboard Program, we have designed the Quality Manager Report. This report provides overseeing managers with a summary comparing the results of their labs for each testing round. Your can view a sample of a Containerboard Quality Manager Report. If your group is interested in setting up a Quality Manager Report, please contact us.

We hope that we adequately explained our Containerboard Interlaboratory Program. Additional information regarding Containerboard testing can be found on our Technical Tips page.

If you have any additional questions about our Containerboard Program, please contact the program coordinator directly through this link