20 th International Conference on Composite Materials Copenhagen, 19-24 th July 2015 PROCESSING PARAMETERS IN MANUFACTURING BIO-BASED COMPOSITES AND THEIR FINISHING WITH LOW TEMPERATURE CURE POWDER COATING Karnika K G De Silva 1 , Clémence Dranebois 2 , Sanjeev Rao 3 , Ben Coombs 3 , Debes Bhattacharyya 3 , Dawn A Smith 2 , Mark P Taylor 1 1 Products Accelerator - Chemicals & Materials Engineering Department, the University of Auckland, New Zealand Email: k.desilva@auckland.ac.nz , mark.taylor@auckland.ac.nz, web page : http://www.productaccelerator.co.nz 2 Scion, 49 Sala Street, Rotorua 3010, New Zealand Email: Clemence.Dranebois@scionresearch.com, Dawn.smith@scionresearch.com web page : http://www.scionresearch.com/ 3 Centre for Advanced Composite Materials - Mechanical Engineering Department, the University of Auckland, New Zealand E-mail: b.coombs@auckland.ac.nz, d.bhattacharyya@auckland.ac.nz web page : www.cacm.auckland.ac.nz Keywords- Design of Experiments, Processing parameters, MDF panels, Powder coating ABSTRACT This study is based on evaluating several environmentally friendly aspects in processing and finishing fibre composites such as low-cost Medium Density Fibre (MDF) boards. These include, introducing sustainable materials to replace currently used toxic formaldehyde based binders and adding value to the composites with solvent-free powder coating with aesthetic finishes. The practicality of using conductive fillers, to enable uniform electrical conductivity on the surface of the panels to achieve uniform surface finish with powder coating is also looked into. This is a relatively new concept in composites to facilitate powder coating. The key properties investigated here in the manufacture of MDF include internal bond strength, modulus of rupture, modulus of elasticity and electrical conductivity. In finishing of the composites, a low-temperature powder coating formulation is evaluated using a thermal analysis method by Differential Scanning Calorimeter (DSC) to study the cure behaviour of powders during processing. In both investigations, full factorial design of experiments (DoE) was used as the most significant tool to detect the factors influencing to optimise the processing parameters to maximise the responses. The focus of this project includes mechanisms for preserving the technological knowledge through new business models funded by the NZ government to support the NZ manufacturing sector, for accelerating innovations and commercialization with targeted research into new products and markets. 1. INTRODUCTION In the recent years, the interest in powder coated MDF panels has rapidly increased. Powder coating can add significant value to these fibreboards through near zero VOC, less hazardous waste than conventional solvent borne liquid coatings and recyclability of the over sprayed paint. Despite the numerous advantages offered by the technology, various issues related to the quality of the final powder coated MDF remain.