Comparative Study of the Properties of Wood Flour and Wood Pellets Manufactured from Secondary Processing Mill Residues

Abstract

The generation of secondary processing mill residues from wood processing facilities is extensive in the United States. Wood flour can be manufactured utilizing these residues and an important application of wood flour is as a filler in the wood–plastic composites (WPCs). Scientific research on wood flour production from mill residues is limited. One of the greatest costs involved in the supply chain of WPCs manufacturing is the transportation cost. Wood flour, constrained by low bulk densities, is commonly transported by truck trailers without attaining allowable weight limits. Because of this, shipping costs often exceed the material costs, consequently increasing raw material costs for WPC manufacturers and the price of finished products. A bulk density study of wood flour (190–220 kg/m3) and wood pellets (700–750 kg/m3) shows that a tractor-trailer can carry more than three times the weight of pellets compared to flour. Thus, this study focuses on exploring the utilization of mill residues from four wood species in Maine to produce raw materials for manufacturing WPCs. Two types of raw materials for the manufacture of WPCs, i.e., wood flour and wood pellets, were produced and a study of their properties was performed. At the species level, red maple 40-mesh wood flour had the highest bulk density and lowest moisture content. Spruce-fir wood flour particles were the finest (dgw of 0.18 mm). For all species, the 18–40 wood flour mesh size possessed the highest aspect ratio. Similarly, on average, wood pellets manufactured from 40-mesh particles had a lower moisture content, higher bulk density, and better durability than the pellets from unsieved wood flour. Red maple pellets had the lowest moisture content (0.12%) and the highest bulk density (738 kg/m3). The results concluded that the processing of residues into wood flour and then into pellets reduced the moisture content by 76.8% and increased the bulk density by 747%. These material property parameters are an important attempt to provide information that can facilitate the more cost-efficient transport of wood residue feedstocks over longer distances.

Additive Manufacturing of Wood Composite Panels for Individual Layer Fabrication (ILF)

“…Hence, the deviation was mostly made up of unbound wood particles and not caused by spread of the dispensed adhesive. These unbound particles were most likely jammed together by high pressure, their morphology, and adhesive chemicals intrinsic to the wood [ 37 , 38 ]. Partially bound wood particles could clamp unbound wood particles to the side of the cuboids, which in turn clamped other unbound particles themselves.…”

Properties of Wood–Plastic Composites Manufactured from Two Different Wood Feedstocks: Wood Flour and Wood Pellets

“…For the manufacturing of WPCs, the raw material based on wood, i.e., wood flour and wood pellets were prepared in the laboratory using local mill processing residues in Maine, USA. Part I of this paper series [ 23 ] has detailed information on equipment used and processing parameters followed during manufacturing of wood flour and wood pellets. The mill residues were clean (free from barks, adhesives, metals, etc.)…”

“… Wood flour and wood pellets used as wood feedstock in WPCs ( a ) Cedar, ( b ) Pine, ( c ) Spruce-fir, ( d ) Maple. (Image source for wood pellets: [ 23 ]). …”

“…However, no research has focused on transportation of raw materials for WPCs manufacturing in a cost-effective way. The first part of this study presented the results on the characterization of the properties of wood flour and wood pellets produced from secondary processing mill residues [ 23 ]. Wood flour and wood pellets were made from four different wood species: Northern White Cedar ( Thuja occidentalis, Eastern White Pine ( Pinus strobus ), Eastern Spruce-Balsam Fir ( Picea rubens-Abies balsamea) and Red Maple ( Acer rubrum ).…”

A Preliminary Study of Scanning Electron Microscopy (SEM) for Characterization of the Wood Pellet Process of Sengon Wood (Albizia Chinensis)

“…KCl behaves identically to Cl, preferably appearing in the sample of adherent impurities. [8], [9], [10], [11] The efficient and profitable combustion of biomass is often limited by operational problems related to ash. Knowledge of ash smelting and sintering is very important, in terms of predicting and mitigating ash-related problems in biomass-fired boilers.…”