Extensional Stiffness sensor provides on-line measurement of non-destructive strength. This sensor measures tensile stiffness response with load cells aligned in the MD and CD axis. The stretch of the sheet is induced by a smooth rotating sphere, inserted into the moving sheet. The resultant forces measured by the load cell are processed to yield Extensional Stiffness (ES) in the MD and CD directions.

Strength measurement is acquired without waiting for additional processing – end of reel sampling, destructive lab testing, and inventory holds. This measurement is directly related to Tensile test method (TAPPI T494 Tensile Stiffness). It is also proportional to Tensile Stiffness Index (TSI).

In contrast to fiber-orientation by reflective light, Extensional Stiffness (ES) is a through-bulk measurement that will reveal the true strength characteristics of a single or multi-ply board. The availability of this information to the production team is very valuable. While production is in progress, Extensional Stiffness information can be used to adjust upstream variables for strength – recycle mix, refining, speed, and jet-to-wire ratio.

Most importantly, when strength information was infrequently available from the lab, people were less likely to respond to process changes. This information will allow you to drive more value out of your process.