New particleboards for food-packaging from poplar peeling by-products using a circular economy approach

Poplar ( Populus x canadenses Moench.) veneers (PWV) are a sustainable raw material traditionally used for producing food-packaging containers. However, the poplar log peeling process, to obtain veneers with a thickness of 0.8–2 mm, generates a large amount of waste, mostly consisting of bark and clippings from veneer sheets. The current work is focused on using these by-products to produce a new material, in the form of thin particleboards , that can be used for package production. The clippings from veneer sheets were dried and milled, and then sieved to obtain different particle size fractions. A bioadhesive, based on poplar bark extract combined with citric acid , was combined with the particles to produce single layer 210 mm × 210 mm x 2 mm particleboards by heat-pressing (press temperature = 160 °C, pressing time = 10 min, resin load = 10 wt%). It was possible to produce 100 % biobased particleboards in which the internal bond resistance and the moisture-resistance properties surpass the EN 312 requirements for boards type P3 for non load-bearing boards used in humid conditions, without the addition paraffin or any other additive. This work shows that the valorisation of by-products of poplar wood veneer production allows manufacturing high-performance particleboards, that can be used by the same industry to manufacture food-packaging containers. The viability of recycling used particleboards was demonstrated, yielding products with enough performance to be used in the production of new packaging products, and an alternative to the possible composting of these particleboards.