Cellulose (2020) 27:7215–7225 https://doi.org/10.1007/s10570-020-03264-w (0123456789().,-volV) (0123456789().,-volV)
ORIGINAL RESEARCH
Enhancing packaging board properties using micro- and nanofibers prepared from recycled board
. Terhi Suopaja¨rvi . Henrikki Liimatainen
Ossi Laitinen
Received: 13 January 2020 / Accepted: 23 May 2020 / Published online: 29 May 2020 The Author(s) 2020
Abstract In this study, cellulose microfibers and cellulose nanofibers (CNF) prepared from recycled boxboard pulp using a mechanical fine friction grinder were used as reinforcements in a board sheet. Micro- and nanofibers manufactured by mechanical grinding have typically broad particle size distribution, and they can contain both micro- and nano-sized fibrils. Deep eutectic solvent of choline chloride and urea was used as a non-hydrolytic pretreatment medium for the CNF, and reference CNF were used without any chemical pretreatment. The CNF were ground using three grinding levels (grinding time) and their dosage in the board varied from 2 to 6 wt%. The results indicate that the board properties could be tailored to obtain a balance between the processability and quality of the products by adjusting the amount of CNF that was added (2–6 wt%). A preliminary cost assessment indicated that the most economical way to
enhance the board strength properties was to add around 4% of CNF with a moderate grinding level (i.e., grinding energy of 3–4 kWh/kg). Overall, the strength properties of the manufactured board sheets improved by several dozen percentages when CNF was used as the reinforcement. Boxboard Cellulose nanofibers Deep eutectic solvents Fine friction grinding Microfibers Nanocellulose Reinforcement Keywords
Introduction
The production of nano-scale cellulose fibers (nanocelluloses) and their application as reinforce- ments in materials have gained increasing attention due to the high strength and stiffness of the nanocel- luloses combined with their small size, high surface area and aspect ratio, low weight, biodegradability, and renewability (Siro´ and Plackett 2010; Hassan et al. 2011; Suopaja¨rvi et al. 2017). Cellulose nanofibrils or nanofibers (CNF) produced by mechanical disintegra- tion of cellulose without any chemical treatments are one of the simplest types of nanomaterials based on renewable resources. CNF manufactured by mechan- ical treatments alone are polydisperse with a broad particle size distribution, and they can contain both micro- and nano-sized fibrils (Kangas et al. 2014).
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10570-020-03264-w) contains supplementary material, which is available to autho- rized users.
O. Laitinen ( & ) T. Suopaja¨rvi H. Liimatainen Fiber and Particle Engineering, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland e-mail: ossi.laitinen@oulu.fi
T. Suopaja¨rvi e-mail: terhi.suopajarvi@oulu.fi H. Liimatainen e-mail: henrikki.liimatainen@oulu.fi
123
Made with FlippingBook - Online catalogs