Valorisation of waste pulp from materials recovery facility rejects for composite applications

Waste pulp was recovered from MRF rejects, purified, processed into paper sheets and laminated with polylactide (PLLA) films. The purification process employed produced waste pulp of different qualities. The mechanical properties of the resulting waste pulp fibre-reinforced laminated PLLA composites was indifferent to the type of waste pulp treatment used. All composites showed significant improvements over neat PLLA, highlighting the viability of using waste pulp as a potentially cheap and sustainable reinforcement for polymers. Lifecycle assessment further showed that the composites possessed lower net global warming potential, as well as the endpoint impact categories of human health and ecosystem quality compared to neat PLLA. This is due to the higher mechanical performance of the composites, which leads to higher weight saving of the functional unit. Our work paves the way for the use of pulp rejects from the recycling process for higher value applications, diverting them from landfill or incineration.