Tensile

1. Adjust refining, if other tests permit.
— increase refining to raise tensile.
— ensure that proper refining tackle is in place to obtain kind and degree of refining required.
— increasing refining consistency improves tensile.
2. Check ash content of sheet.
— a high ash contributes to low tensile.
3. Check wet-end hydraulics (total head, jet/wire ratio, machine speed, etc.) which all affect tensile and tensile ratio.
4. Increase sheet moisture entering size press to improve pick-up and penetration.
5. Reduce headbox consistency to improve formation, if drainage will permit.
— a change in recycle flow to the headbox will change the total head and jet/wire ratio.
6. Adjust head to improve formation.
— good formation contributes to high tensile.
— adjust shake speed if appropriate.
7. Check levels of strength additives, such as starch or gums.
8. Investigate possible use of higher strength pulps.
9. Check fly-roll speed between couch and first press.
— if turning too fast can adversely affect tensile.
10. Check and adjust foil location and blade angles for improved formation.
11. Adjust wet end draws.
— loosen draw to improve CD tensile.
— tighten draw for better MD tensile.