Mechanical Properties of Spaceboard Panels and Pallets Made from Recycled Linerboard Mill Sludge, 1997 Environmental Conference Proceedings

Every day, paper mills landfill or burn 3 to 50 metric tons of fiber that might otherwise be used for value-added structural packaging products. Sludge from a recycled linerboard mill was used to form Spaceboard subpanels for Conversion Technologies Industries, Inc.. The sludge was used “as is” without any pre-processing or chemical additives or adhesives. The subpanels can be described as fiber-formed, three-dimensional, high-density structures having an integral rib and face structure. These subpanels were combined into a sandwich structure 2.0 cm thick by bonding the ribs together. Edge crush, center point bending, and flat crush tests were conducted to investigate initial mechanical properties of the sludge panels and to assess the potential use of such panels in a structural product, specifically a standard 101.6 by 121.9 cm (40 by 48 inch) four-way entry pallet. Nine pallets of three preliminary configurations were tested to determine bending strength properties based on the Australian Standard AS 4068. This paper discusses the measured panel strength properties and the results from the initial pallet tests. These preliminary tests show sludge material has the potential for use in structural panels and structural product applications.