WOOD RESEARCH Volume 70, Number 4, 2025
ANDREJ PAŽITNÝ, JURAJ KRIŠTA, and MARTA PÁTEKOVÁ

IMPROVING SHEET MATERIAL PROPERTIES IN PAPERMAKING FROM SECONDARY FIBER AND CORN KERNEL’S CASING

The paper is focused on monitoring the impact of corn kernel’s casing content added to old corrugated containers on density, brightness, ultimate tensile load, tensile index, tensile energy absorption, breaking length, tensile strength, relative elongation, air resistance of paper sheet according to Gurley and zero-span tensile strength. A content of 40 % and 60 % corn kernel’s casing added to secondary fiber based on old corrugated containers was tested. Suspensionsprepared by acidification and beating were subjected to chelation and three-stage bleaching.The bleaching method consisting of three steps was applied in two series – acidified and beaten pulp suspension with Schopper-Riegler (°SR) beating degree at level of 72 °SR.The first bleaching step includedperoxide bleaching with added sodium hydroxide, chlorine dioxide bleaching and peroxide bleaching in an alkaline environment. The effect of chemical and hydro-mechanical treatment on the resulting physical and mechanical characteristics of prepared paper sheets was investigated.

WOOD RESEARCH Volume 63, Number 4, 2018
Ekrem Durmaz, Saim Ates, Laboni Ahsan, Zhibin He, and Yonghao Ni

Characterization of microfibrillarcellulose (MFC) obtained from corn stalk, sunflower stalk, reed and sesame husk

Microfibrillar cellulose (MFC) samples from different agricultural resources and their wastes were characterized and compared in this study. MFCs were prepared from corn stalk, sunflower stalk, reed and sesame husk by two different methods. Hydrochloric acid (HCl) was used in Method 1, while formic acid (CH2O2) and sulphuric acid (H2SO4) were used in Method 2. SEM, FTIR, XRD and TGA analyses were conducted to determine the morphological, physical and thermal properties of the MFCs. The widths of the MFCs varied between 2.35 μm – 7.96 μm depending on the treatment methods and the raw materials. The crystallinity index of the lignocellulose increased after the chemical treatment, and the highest crystallinity index was found to be 82.0% for the sesame husk treated by Method 2. FTIR results indicate the presence of cellulose (~1640 cm-1), hemicellulose (1740 cm-1), lignin (1510 cm-1) and the other components in the MFCs. The TGA results show that the decomposition temperatures for the treated samples were higher than those for the untreated samples, indicating that the chemical treatments increased the thermal stability of the MFCs. As a consequence, it was seen that agricultural resources and their wastes can be an effective raw material in production of MFCs.