Physical and Tensile Properties of Handmade Sida rhombifolia Paper

Material Properties of Traditional Handmade Paper Samples Fabricated from Cellulosic Fiber of Lokta Bushes

Handmade papers (HPs) are fabricated from fibrous biomass of Lokta bushes and other plant species following traditional eco-friendly method in Nepal. Although HP fabricated from Lokta bushes is believed to be durable and resistant to bugs and molds, material properties of this paper are not reported in literature. In this study, we measured several material properties of 10 handmade Lokta paper samples collected from local enterprises and paper industries. The mean caliper, grammage, apparent density, equilibrium moisture content, Cobb 60, brightness, opacity, tensile strength, and tensile index values in the paper samples ranged from ∼90 to 700 μm, 50 to 150 g/m², 0.2 to 0.4 g/cm³, 4 to 7%, 50 to 400 g/m², 56 to 67%, 83 to 98%, 30 to 2900 N/m, and 1 to 27 Nm/g, respectively. These properties suggested that the HPs are lightweight papers with intermediate to high strength. The tensile strength was found to be significantly higher along the length direction (p < 0.05). Characteristic features of cellulose, hemicellulose, and lignin were observed in FTIR spectra. The crystalline and amorphous phases were also identified in X-ray diffraction (XRD) data. Electron microscopy images revealed a nicely cross-linked network of intact fibers having almost parallel arrangement of microfibrils. These features could provide strength and durability to the paper samples. Understanding the material properties of HPs down to the sub-microscopic level may help improve the paper quality and find novel applications in the future.

Glycome Profiling and Bioprospecting Potential of the Himalayan Buddhist Handmade Paper of Tawang Region of Arunachal Pradesh

The paper and pulp industry (PPI) is one of the largest industries that contribute to the growing economy of the world. While wood remains the primary raw material of the PPIs, the demand for paper has also grown alongside the expanding global population, leading to deforestation and ecological imbalance. Wood-based paper production is associated with enormous utilization of water resources and the release of different wastes and untreated sludge that degrades the quality of the environment and makes it unsafe for living creatures. In line with this, the indigenous handmade paper making from the bark of Daphne papyracea, Wall. ex G. Don by the Monpa tribe of Arunachal Pradesh, India is considered as a potential alternative to non-wood fiber. This study discusses the species distribution modeling of D. papyracea, community-based production of the paper, and glycome profiling of the paper by plant cell wall glycan-directed monoclonal antibodies. The algorithms used for ecological and geographical modeling indicated the maximum predictive distribution of the plant toward the western parts of Arunachal Pradesh. It was also found that the suitable distribution of D. papyracea was largely affected by the precipitation and temperature variables. Plant cell walls are primarily made up of cellulose, hemicellulose, lignin, pectin, and glycoproteins. Non-cellulosic cell wall glycans contribute significantly to various physical properties such as density, crystallinity, and tensile strength of plant cell walls. Therefore, a detailed analysis of non-cellulosic cell wall glycan through glycome profiling and glycosyl residue composition analysis is important for the polymeric composition and commercial processing of D. papyracea paper. ELISA-based glycome profiling results demonstrated that major classes of cell wall glycans such as xylan, arabinogalactans, and rhamnogalacturonan-I were present on D. papyracea paper. The presence of these polymers in the Himalayan Buddhist handmade paper of Arunachal Pradesh is correlated with its high tensile strength. The results of this study imply that non-cellulosic cell wall glycans are required for the production of high-quality paper. To summarize, immediate action is required to strengthen the centuries-old practice of handmade paper, which can be achieved through education, workshops, technical know-how, and effective marketing aid to entrepreneurs.