PAPERmaking! g FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 2, Number 1, 2016
Fig. 9. Burst strength as a function of ash content in handsheets made from white ledger and C-PAMs
Fig. 10. Compressive strength as a function of ash content in handsheets made from white ledger and C-PAMs CONCLUSIONS 1. White ledger contained fibre fines and filler fines, which resulted in inferior paper strength compared with the strength of paper made with BKP. Thus, first-pass retention is very important when the amount of white ledger increases in the top ply of a duplex board. Sheet strength must be monitored because an increase in first-pass retention is directly related to an increase in ash content. In addition, a proper additive must be selected. 2. The charge density of a C-PAM, which acts as a retention aid, is more important than its molecular weight in terms of simultaneously improving the first-pass retention and strength of white ledger paper. The charge density must be sufficiently high to allow the C-PAM to catch anionic fine particles. ACKNOWLEDGEMENTS This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. NRF-2015R1A2A2A01006463).
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Article 1 – Improving Retention and Strength
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