understand that a web break is caused by a weak point in the paper web. The overall strength of the web is high enough.
know that the weak point in the paper is normally a defect such as a hole, shive, or wrinkle.
know that the uneven strain profile creates a high risk of web break. The situation is worse when a big difference in strain exists between the edges of the roll.
Based on: Suontausta, O. End-use properties of printing papers (Chapter 9). In: Levlin, J-E. & Sjöderhelm, L. (ed), Pulp and paper testing (Book 17), Papermaking Science and Technology. Jyväskylä. 1999. Fapet Oy. pp. 183-215.
References:
Linna, H., “Runnability in web offset printing”, Paperi painokoneessa, AEL Insko, Jyväskylä, 1994, 1, 13 p. (in Finnish).
Linna, H., “Paper rheology and runnability properties”, Proceedings of the 20th Research Conference of the International Association of Research Institutes for the Graphic Arts Industry, International Assoc. of Res. Inst. for the Graphic Arts Ind., 1989, p. 301.
Salmen, N. and Back, E., Svensk Papperstid. 80(6):178(1977).
Yamauchi, T., Okumura, S., Murakami K., Journal of Pulp and Paper Science 15(l):J23(1989).
Linna, H. and Moilanen, P., Tappi J. 71(10):134(1988).
Marttinen, T., “A Contactless Tension Profile Meter”, Ph.D. Dissertation, University of Helsinki, Helsinki, Finland, 1994.
Linna, H., Kaljunen, T., Parola., M., Paperi Puu 77(5):279(1995)
