Development of Wood Composites from Recycled Fibres Bonded with Magnesium Lignosulfonate

Abstract

The potential of producing ecofriendly composites from industrial waste fibres, bonded with magnesium lignosulfonate, a lignin-based formaldehyde-free adhesive, was investigated in this work. Composites were produced in the laboratory using the following parameters: a hot press temperature of 210 °C, a pressing time of 16 min, and a 15% gluing content of magnesium lignosulfonate (on the dry fibres). The physical and mechanical properties of the produced composites were evaluated and compared with the European Standard (EN) required properties (EN 312, EN 622-5) of common wood-based panels, such as particleboards for internal use in dry conditions (type P2), load-bearing particleboards for use in humid conditions (type P5), heavy-duty load-bearing particleboards for use in humid conditions (type P7), and medium-density fibreboards (MDF) for use in dry conditions. In general, the new produced composites exhibited satisfactory mechanical properties: a bending strength (MOR) (18.5 N·mm−2) that was 42% higher than that required for type P2 particleboards (13 N·mm−2) and 16% higher than that required for type P5 particleboards (16 N·mm−2). Additionally, the modulus of elasticity (MOE) of composites (2225 N·mm−2) was 24% higher than that required for type P2 particleboards (1800 N·mm−2) and equivalent to the required MOE of MDF panels for use in dry conditions (2200 N·mm−2). However, these ecofriendly composites showed deteriorated moisture properties, i.e., 24 h swelling and 24 h water absorption, which were a distinct disadvantage. This should be further investigated, as modifications in the lignosulfonate formula used and/or production parameters are necessary.

Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

“…In accordance with the free formaldehyde content results, the reference HDF panel, bonded with 6% UF resin only, can be classified under the emission class E1 (≤8 mg/100 g). These results are in agreement with previous research, where using lignosulfonates as binders for wood composites resulted in decreased free formaldehyde content [ 6 , 9 , 45 , 69 ]. ALS has very good characteristics for methylolation due to its large number of phenolic hydroxyl groups and amount of aromatic protons of the guaiacyl units, whose presence tends to increase the reactivity of lignosulfonate toward formaldehyde [ 94 , 95 ].…”

“…The growing need for sustainable products and the stringent legislative requirements related to the hazardous formaldehyde emissions from wood-based panels have boosted scientific and industrial interest in the production of eco-friendly, wood-based panels [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ] and optimal utilization of the available lignocellulosic materials [ 8 , 9 , 10 , 11 , 12 , 13 ].…”

“…Different renewable biomass resources, such as proteins [ 58 , 59 , 60 ], starch [ 61 , 62 ], tannins [ 63 , 64 , 65 ], and lignin [ 9 , 66 , 67 , 68 , 69 ] have been used as sustainable raw materials for the development of bio-based adhesives for engineered wood panels.…”

Eco-Friendly Fiberboard Panels from Recycled Fibers Bonded with Calcium Lignosulfonate

“…In 2019, the annual global production of wood-based composites was estimated to be 357 million m 3 , which represents an increase of 268% compared to 1980 [ 4 ]. The possibilities to reduce the increased consumption of wood raw materials include recycling of waste wood-based panels at the end of their life cycle [ 5 , 6 , 7 , 8 , 9 , 10 ], utilization of alternative raw materials [ 11 , 12 , 13 , 14 , 15 ], and use of waste lignocellulosic materials [ 16 , 17 , 18 ].…”

“…Recent developments in the field of sustainable, bio-based adhesives include the use of different renewable biomass feedstocks, such as proteins [ 69 , 70 , 71 , 72 , 73 ], starch [ 74 , 75 ], tannins [ 76 , 77 , 78 ], and lignin [ 17 , 79 , 80 , 81 , 82 , 83 , 84 ]. The development of alternative value-added wood composites that use waste materials or recycled materials is becoming beneficial due to over exploitation of natural resources.…”