New to the Containerboard Program?

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 about how the program works.

CTS offers a wide variety of tests for linerboard, medium, corrugated boxes and corrugated board. Please view the tests listed under each material to familiarize yourself with the tests offered. All of the tests are explained in the Test Description document.  You may select any combination of tests that are appropriate for your laboratory.

Our Materials

The Containerboard Program materials come from actual mill production. CTS works with industry suppliers to obtain a narrow, roll of linerboard or medium, from the middle of the reel from a mchine that is known to be producing consistent stock. The use of a narrow roll, usually 38" or 50",  helps to minimize cross machine variation. The roll is then slit down to 12" portions.  The 12" 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 among the sample packs. 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 for ECT and corrugated boxes for BCT are selected and randomized in a similar manner. Corrugated boxes are manufactured for the program from the minimum nuber of consecutive corrugated sheets needed for the lot size.  The corrugated board used for ECT is also derived from consecutive corrugator sheets with no changes in linerboard or medium rolls during the run.  The ECT samples are then manufactured on a cutting table.  The ECT blanks are randomized, preconditioned and sealed in moisture-proof, barrier material.  The corrugated boxes for compression testing are also randomized by CTS and subdivided into lab lots that will last for the entire testing year.  However, due to the size of the boxes, the corrugated box samples 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 Program tests.

Your Samples

The sample package you receive contains test samples and data reporting sheets on which testing results are sent to CTS. Please note, the Specific Test Instructions are always available here on the Web site. Your lab should keep the instructions for reference in further test cycles; CTS will notify all participants if the Specific Test Instructions change.  The Containerboard Program adheres to the TAPPI Test Method for each property and for sample conditioning and preconditioning.  The Specific Test Instructions contain admendments and additions to the test method to ensure that the results from all participating laboratories may be compared.

When to expect your testing package

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.

Submitting your results

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.

Analysis

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. The Sample Individual Report and Guide to Individual Reports show laboratories the statistics used in the reports.

Performance Analysis Report

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. Again, you can view a sample of the Individual Report sent to participants in the Containerboard Interlaboratory Program using the link above, but keep in mind your report will reflect your data.

Web Summary Report

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 section to view results for the previous 5 years of testing.

Quality Manager Report

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.

Still have questions?

We would like to hear from you.  Call us at 571-434-1925 or send us an email through the link on our Contacts page.