Producing Floor and Side Panels from Biocomposites

Abstract

High pressure laminates for floor and wall coverings mainly consist of wood fibres and resins. Such laminates are made of a high density fibre board core and several paper sheets glued to the core to obtain a decorative, strong, and durable panel. Disposal or reuse of multi-material composite structures is challenging because the materials might not be separable. Interest in more sustainable products and industrial solutions have increased in the recent years, and similarly, regulations and laws are becoming stricter, for example on formaldehyde emissions in building materials. The present thesis aims to develop a way of producing floor and wall coverings from biocomposites by replacing, reusing and reducing material. This is to create biocomposite flooring that is more sustainable and lighter while maintaining critical properties of the current flooring laminates.

To address the mentioned issues, a biocomposite formulation, a core panel design and a manufacturing method considered to be suitable for the application were developed. Requirements for the biocomposite core were established to design the core accordingly. Biocomposite formulations of poly(lactic acid), different weight fractions of thermomechanical pulp fibres and an industrial side stream from laminate production were prepared and assessed. Different sandwich structure designs with in-plane and out-of-plane oriented cells were manufactured by 3D printing and mechanically tested. The 3D-printed core design was developed using finite element analysis. A bimodular material model was applied and fitted to capture the elastic/plastic behaviour of the 3D-printed parts under bending.

Additionally, a proof of concept of biocomposite core panels with unidirectional core stiffeners manufactured in profile extrusion was performed. Promising alternatives for the biocomposite material, core design and manufacturing method were weighted against each other using an approach adapted from systems engineering. Finally, a biocomposite core made of poly(lactic acid) and 30 wt.% thermomechanical pulp fibres, with an arched core design and manufactured in profile extrusion was demonstrated and considered to be a suitable replacement for the currently used laminate core.