TAPPI/ANSI T 809 is a test method for measuring the flat crush resistance of corrugating medium after it is laboratory-fluted (often referred to as the Concora Medium Test, or CMT). It is used to evaluate how well corrugating medium resists flute collapse under compression.
This standard is commonly used by containerboard mills, corrugators, and packaging QA teams to screen medium quality and to help estimate the potential flat crush resistance contribution of the medium to corrugated board performance. If you need help matching this method to your lab setup or to the edition cited by a customer specification, you can talk with our team.
Flat crush of corrugating medium (CMT test), TAPPI/ANSI T 809
TAPPI/ANSI T 809 describes a controlled lab procedure that forms a strip of corrugating medium into a fluted shape using a laboratory fluter, then compresses that fluted specimen to determine flat crush resistance.
The output is used as a quality-control measure for corrugating medium and as an input for packaging performance discussions where flute integrity and crush resistance are important.
Quick Definition
TAPPI/ANSI T 809 is a corrugating-medium test method that reports the flat crush resistance of a laboratory-fluted strip (CMT).
What This Standard Covers
This method covers the preparation and compression testing of a fluted strip made from corrugating medium (the paper used to form flutes in corrugated board). The procedure focuses on measuring the crushing resistance of that fluted structure when loaded perpendicular to the flute tips (flat crush).
Because the specimen is laboratory-fluted, results are intended to support material control and comparison of corrugating medium rather than to replace combined-board testing on finished corrugated fiberboard.
Why This Standard Matters in Testing
Flute integrity is a key contributor to corrugated board performance. If corrugating medium crushes easily during converting or under top-load conditions, finished packaging can lose stiffness and stacking capability.
T 809 is widely used as a practical incoming or process control test for corrugating medium, helping mills and box plants maintain consistency and investigate shifts in medium performance that may impact downstream board properties.
Common Materials, Product Types, or Applications Covered
Common materials: Corrugating medium used for manufacturing corrugated board (containerboard component paper).
Common applications: Containerboard quality programs, corrugator process monitoring, supplier qualification, and troubleshooting when flute collapse or reduced crush resistance is suspected.
Common Test or Verification Workflow
Most labs run TAPPI/ANSI T 809 as a repeatable workflow that starts with strip preparation, followed by laboratory fluting, then compression testing of the fluted specimen to obtain a maximum crush resistance value.
Common workflow steps: Prepare strips of corrugating medium, flute them on a laboratory fluter, handle/fixture the fluted specimen as required by the method, and compress to determine flat crush resistance for reporting and comparison.
Equipment Commonly Used for This Standard
T 809 is equipment-oriented because specimen forming is part of the method and test-to-test consistency depends heavily on fluting and compression setup.
Common equipment families: Laboratory medium fluter (Concora-type) with heated fluting rolls, specimen strip cutter/die cutter, rack/comb or equivalent forming/holding accessories (as required by the method), and a compression tester suitable for flat crush-style loading of the fluted specimen.
Practical selection caution: Configuration details (platens, anti-slip surfaces, fixtures, and specimen-handling timing) can materially affect results, so the compression tester and fluter should be selected and set up to match the exact edition cited in your quality program.
How to Read This Designation or Revision
Designation: “T 809” is the TAPPI method number for this corrugating medium flat crush (CMT) procedure.
Revision suffix: The “om-22” suffix indicates an Official Method edition associated with the year 2022. Older specifications may cite earlier “om-” year versions, and equipment and reporting expectations can vary with the cited edition.
Related Standards, Methods, or Frameworks
Depending on how your customer specifications are written, TAPPI/ANSI T 809 may be used alongside other corrugated and containerboard test methods that evaluate crush resistance at the paper, medium, or combined-board level.
Commonly paired needs: Conditioning/standard atmosphere control for paper testing, and separate methods for flat crush or compression performance of corrugated board (as opposed to corrugating medium).
Get help selecting a TAPPI T 809 test setup
If you are equipping a lab for CMT or updating an existing line (medium fluter, strip cutter, and compression tester), you can request a detailed quote with options aligned to your sample volume and the exact TAPPI T 809 edition you need to run.