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• Multidisciplinary evaluation of three novel perennial crops as feedstock for the pulp and paper industry. • Meadow hay blends generated higher tensile indices compared to the pure birch control. • Fibre lengths of 0.5 (meadow hay), 1.3 (Virginia mallow), and 0.9 mm (cup plant) were measured. • The fibre widths of cup plant and Virginia mallow are broader compared to hardwoods. • These promising raw materials will be valueable in cardboard production for sustainable packaging. While the demand for paper and packaging material is increasing, industry and consumers are searching for more sustainable raw materials. This study evaluates three non-wood perennials to find alternative raw materials for the paper and pulp industry. Meadow hay, cup plant (Silphium perfoliatum L.) and Virginia mallow (Sida hermaphrodita (L.) Rusby) are attracting attention as potential raw materials for the bioeconomy due to biodiversity benefits, low fertilizer requirements as well as high yields. For the first time a detailed view on their fibre morphology and use as paper feedstock is given. After three different mechanical grinding methods, the plant material was screened, pulped in NaOH and beaten in a PFI mill. Birch fibre has been chosen as short-fibre control and blend base. Hand-sheets with different pulp blends of birch and one of the three raw materials were made, and paper properties were measured. For meadow hay, Virginia mallow and cup plant fibre lengths of 0.5, 1.3, and 0.9 mm were measured. Therefore, all perennial plant materials have comparable fibre lengths to hardwoods. Meadow hay blends with birch pulp percentages of 50 % and 75 % generated higher paper strength compared to the pure birch paper at a beating intensity of 5000 revolutions (PFI). The paper strength of cup plant and Virginia mallow blends is comparable to the strength of the birch control. Due to these promising results, all analyzed raw materials could find their application, especially in the growing area of sustainable packaging materials. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we characterized various unconventional pulping raw materials in terms of their contents in hollocelulose, α-cellulose, lignin, ethanol–benzene extractables, ash, and hot water and 1% soda solubles. Also, we characterized pulp obtained from each material by using an ethyleneglycol concentration of 65% at 180°C for 75min, followed by beating at 1500 revolutions in a PFI refiner—all of which are compatible with existing facilities for Kraft and soda pulping processes. We characterized vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus as pulping raw materials and found Ch. proliferus and cotton stalks to be the best for the intended purpose on the grounds of their increased contents in holocellulose (79.73 and 72.86%) and α-cellulose (45.37 and 58.48%), and their decreased contents in ethanol–benzene extractables (2.64 and 1.42%), hot water solubles (2.79 and 3.33%) and 1% soda solubles (16.67 and 20.34%). These properties resulted in increased pulp yields and hence in efficient use of these two types of raw material. The paper sheets obtained of different pulps were characterized and those from Ch. proliferus found to be the best overall as they exhibited an increased breaking length (4644m), stretch (2.87%), burst index (2.46kN/g) tear index (0.33mNm2/g) and brightness (49.92% ISO); in addition Ch. proliferus pulp was obtained with a high yield (62.88%). On the other hand, vine shoots provided the poorest results among the studied raw materials. [Copyright &y& Elsevier]