Properties of cellulose nanofibre networks prepared from never-dried and dried paper mill sludge

Abstract

Paper mills yield large volumes of sludge materials which pose an environmental and economic challenge for disposal, despite the fact that they could be a valuable source for cellulose nanofibres (CNF) production. The aim of the study was to evaluate the production process and properties of CNF prepared by mechanical fibrillation of never-dried and dried paper mill sludge (PMS). Atomic force microscopy (AFM) showed that average diameters for both never-dried and dried paper sludge nanofibres (PSNF) were less than 50 nm. The never-dried and dried sludge nanofibres showed no statistical significant difference (p > 0.05) in strength ~92 MPa, and ~85 MPa and modulus ~11 GPa and ~10 GPa. The study concludes that paper mill sludge can be used in a dried state for CNF production to reduce transportation and storage challenges posed on industrial scale.

Continuous and sustainable cellulose filaments from ionic liquid dissolved paper sludge nanofibres

“…The paper sludge, obtained from a kitchen towel mill, was dispersed in water and mechanically homogenized using a supermass colloider MKCA6-3 (Masuko Sangyo Co, Japan) to prepare CNF fibres as described in an earlier study (Adu et al, 2018). The chemical composition of the CNF was 74% cellulose, 2.6% hemicellulose, as well as inorganic minerals including Ca (947 mg/kg), Si (3694 mg/kg), Mg (1578 mg/kg) and Fe (166 mg/kg).…”

Structural packaging foams prepared by uni-directional freezing of paper sludge cellulose nanofibres and poly (vinyl alcohol)

“…PMS obtained from a UK mill producing kitchen towel rolls was mechanically homogenised using a supermass colloider MKCA6-3 (Masuko Sangyo Co, Japan), details on CNF preparation can be found in our previous study [10]. The CNF had an average width of 50nm, crystallinity index of 43%, chemical composition of 74% cellulose and 2.6% hemicellulose.…”

“…The fundamental process of ice-templating (IT) is based on the growth of ice crystals in a solvent which sublimates, leaving an orderly pore formation in the material [9]. CNF was derived from paper mill sludge (PMS) a by-product of paper mills proven to be a successful source of nanocellulose production due to its reduced processing cost, and no requirement for chemical treatment [10]. The CNF and PVA solution was crosslinked with Sodium tetraborate decahydrate and using the uni-directional freezing method.…”

Paper Waste Recycling. Circular Economy Aspects

“…Characteristics of these fibers were studiedfiber size and mechanical properties, as well as microscopy of atomic forces. The chemical composition of both: the dry and the wet fraction of paper sludge were the same because they were obtained from one factory [15].…”