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Washboarding and print quality of corrugated board
Author(s) -
Netz Erik
Publication year - 1998
Publication title -
packaging technology and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 50
eISSN - 1099-1522
pISSN - 0894-3214
DOI - 10.1002/(sici)1099-1522(199807/08)11:4<145::aid-pts426>3.0.co;2-6
Subject(s) - quality (philosophy) , corrugated fiberboard , engineering drawing , engineering , manufacturing engineering , materials science , mechanical engineering , physics , quantum mechanics
This paper is a concluding survey of the research presented in three previous reports by the author. It deals with the problem of washboarding, which is the wavy pattern coinciding with the flute tips on the surface of corrugated board. The causes of washboarding on the surface of corrugated board have been determined and the effect of washboarding on the print quality of corrugated board has been studied and discussed. Measuring equipment for quantifying washboarding has been developed. Which has a non‐contact, optical measuring device which measures the distance to a corrugated board sheet with an accuracy of 1 μm. The effects of paper properties and process and converting conditions on the degree of washboarding were studied and the effects of the degree of washboarding on the appearance of the unwanted stripes in flexo print (so called printed stripes) has been analysed. The main influencing factor for washboarding to occur on corrugated board surfaces is the amount of glue between the liner and the fluting. The more glue, the more washboarding. The liner grammage is also important; a high liner grammage decreases the degree of washboarding and a low fluting grammage decreases the washboarding. The degree of washboarding influences print quality to a surprisingly low extent, contrary to what has been claimed before, with other parameters influencing the printed result much more. The distance between the plate and the pressure roll (the print nip) and the ratio between the stiffness in the thickness direction of the board and the printing plate, influence quality print dominantly. The type of print, i.e. half‐tone or full‐tone, also influences print quality. It is not possible to get perfect printing results in both half‐tone and full‐tone prints when using the same inking station. To avoid printed stripes on half‐tone areas one should increase the print nip, decrease the fluting stiffness and/or increase the plate hardness. To avoid printed stripes on full‐tone areas one should do the opposite: decrease the print nip, increase fluting stiffness and/or decrease plate hardness. © 1998 John Wiley & Sons, Ltd.