Potential of advance NDT method for water measurement in a bulk paper-recycling

Paper recycling industries usually buy their raw material from suppliers. Bulk used paper supplied to recycling industry may contain water in their internal voids. This is because the price of the used paper is currently based on their weight and has a huge potential of suppliers to add water to increase the price. The aims of our experiment are to establish the neutron calibration curve and to develop a correction factor of weight measurement during purchasing. This study presents an advance non-destructive testing technique for rapid and in-situ measurement of water content in a bulk used paper. A fast neutron source (Am-Be 241) and a portable backscattering neutron detector were used for water measurement. The experiments were conducted by measuring a series of wet paper added with certain amount of water. As a result, a neutron calibration curve for water measurement in bulk used paper was established. A total of six bands for weight correction based on the calibration curve have been proposed. (author)