Large-Scale Production of Powder Adhesives Based on Kraft Lignin

摘要

The feasibility of manufacturing modified kraft lignin adhesives under plant conditions was assessed. Approximately two tons of powdered adhesives were produced in cooperation with three industrial plants and subsequently tested in laboratory-fabricated waferboard. The first stage of the program, the production of methylolated kraft lignin (MKL), was accomplished successfully with the use of existing facilities at a kraft paper mill. Samples of the MKL were subsequently blended with a commercial phenol-formaldehyde resin and the adhesives obtained were assessed in the laboratory. Based on laboratory results and considering cost of raw materials, three formulations were prepared and spray-dried, MKL-PF powdered adhesive was spray-dried by a cooperating adhesive manufacturer and the plant-produced adhesive was tested exhaustively in laboratory scale waferboard panels. Based on current raw material prices and production costs including profit margins, it was estimated that a satisfactory adhesive could be produced at half the cost of presently used phenol-formaldehyde resins.