Variation of gravure coating thickness during early stages of doctor blade wear
✍ Scribed by R. Hanumanthu
- Book ID
- 101431302
- Publisher
- American Institute of Chemical Engineers
- Year
- 1999
- Tongue
- English
- Weight
- 212 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0001-1541
No coin nor oath required. For personal study only.
✦ Synopsis
With all operating parameters fixed, the mean coated thickness in gra®ure coating should ideally be a constant fraction of the ®olume factor of the engra®ing, and, hence, in®ariant o®er coated distance. Experimental data presented, howe®er, re®eal an unexpected ®ariation of gra®ure coating thickness o®er the first few thousand meters of coated web. The obser®ed ®ariation is attributed to wear of the blade tip. The lubrication approximation is in®oked to model a series of steady-state flows between blade tips of ®arious profiles and a smooth surface at a fixed gap away from them. The blade tip profiles are chosen to simulate those of a continously wearing blade tip. The resulting four-parameter model is used to '' fit'' experimental data of gra®ure coating thickness ®ariation. Then, the model is used to predict the effects of ®arious operating parameters, including coating liquid properties, blade thickness, blade setup, and web speed, on this phenomenon.