Utveckling av ett träbaserat moduluppbyggt möbelsystem

Until recently, furniture of high quality at a low price was a contradiction. The Modos modular furniture system, which was launched at the end of 2014, has the potential to break this contradiction. By using standardized aluminium connectors and rectangular wood based boards, various types of furniture can be assembled and disassembled many times – without the any tools. Despite its great potential the Modos system has a few shortcomings, caused by the aluminium connectors. Modos is not particularly cheap, and from an environmental perspective, there is room for improvement. For this reason, the objective of this project was the development of a similar modular furniture system, which would be entirely wood based. Wood is more eco-friendly, as well as arguably cheaper and more beautiful. A secondary objective was to evaluate the benefits of lean product development principles.The main challenge from a technological viewpoint was to achieve a sufficient structural strength of the wood based connectors, without significantly compromising the design. From a project planning perspective, the critical task was to manage the free flowing process of developing an innovative and design driven product.By applying lean principles, the product development process went smoothly and could be completed within the best-case time frame. The resulting product – called ‘Notofusy’ – met all the requirements as far they could be assessed. Notofusy is stable, flexible, eco-friendly, and most likely somewhat cheaper than Modos. However, before Notofusy can be launched, some details, such as precise manufacturing costs, have to be addressed and worked out.Validerat; 20150225 (global_studentproject_submitter

Surface Densification of Solid Wood : Paving the Way Towards Industrial Implementation

Surface densification of a piece of solid wood results in an increase in density and in hardness in the whole or a part of the densified material, and is one of the ways of improving the properties and value of low-density wood species. Despite efforts for many years, mass commercialisation of either bulk- or surface-densified wood products has not yet been achieved. Most of the previously tested densification methods have limitations in terms of processing speed and integration into the largely continuous wood processing chain, which leads to high production costs. Established methods to eliminate the set-recovery rely either on technologically complex close-system methods or on open-system methods that require relatively long periods of high energy input. For this reason, impregnation with adhesives is used in almost all commercially available densified wood products, and none of them have risen above their status of being niche products. Based on this background, three objectives for this project were formulated: (1) the development of a method for selecting the most suitable wood species for surface densification, (2) showing that surface densification can be carried out in a continuous manner at high process speeds, (3) and researching a fast open-system method to reduce the set- recovery. The method developed for selecting the most suitable wood species for surface densification was based on Lean principles, and it confirmed the suitability of previously studied wood species, such as Scots pine, spruce and poplar. In addition, several suitable alternatives from different parts of the world and from different types of forest were identified. This suggests a high potential for establishing such wood products on a global market level. Two studies using a continuous roller press showed that solid wood can be successfully surface-densified at process speeds of up to 80 m min-1, and that some defects, such as knots, are acceptable in the raw material, but the problem of set-recovery could not however be solved. A screening experiment testing different open-system approaches to reduce the set-recovery highlighted the potential of a novel method using ionic liquids as a plasticiser prior to the surface densification of solid Scots pine. The set-recovery could be reduced to 10%, with the time of high energy input being less than 10 minutes. The Brinell hardness was increased by a factor of 2.7 over that of undensified wood. A study with thermo-gravimetric analysis and digital image correlation showed that the set-recovery almost exclusively happens in the transition zone between the densified and undensified wood cells, where there is less penetration of the ionic liquids. The work accomplished in this project has successfully addressed several gaps in the field of wood densification, firstly, by employing a continuous surface densification process using a roller press, and secondly, by developing and studying a fast open-system pre-treatment with ionic liquids, which greatly reduces the set-recovery. Research will continue on a new band press, facilitating a swift transfer of knowledge between small- scale studies and the continuous surface densification of production-size wooden boards

Surface-Densified Wood : From Laboratory-Scale Research Towards a Competitive Product

For many decades, humans have been consuming more resources than the world has to offer in the long run. Increasing the use of renewable materials, such as wood, is essential if we are to achieve a sustainable use of the resources available to us. Densification of wood in general, and surface densification in particular, has the potential to improve the properties of widely available low-density wood species, opening up new fields of application, and fostering the use of wood products in general. The objective of this thesis is to put past research within the field of surface densification of solid wood and advancements within the present project into a context, and to suggest a path towards a performance-driven and cost-effective type of product. A prevalent research gap has been identified and this thesis summarizes how this gap can be filled by already conducted and future studies. Important aspects that need be handled in order to fulfill the overall vision of the large-scale commercialization of surface-densified wood products are considered. Past studies were successful in gaining a good understanding of different approaches to the densification of solid wood, such as using a hot press or a friction welding machine. Problems, such as the moisture-induced recovery of the densified wood cells could be solved from a technological perspective. However, those studies did not take into account industrial implementation. Existing methods are time- and/or energy-consuming. The use of roller-pressing equipment showed promising results, but also highlighted certain limitations. Solid wooden boards have been successfully surface-densified at speeds of up to 80 m/min. However, problems arose regarding the plasticization and stabilization of the densified wood cells, indicating that a continuous belt-press approach might be more viable with regard to the objective of industrial implementation. In parallel, a structured method to identify the most suitable wood species for surface densification has been presented, with the aim of propagating the use of surface-densified wood products and widening their fields of application. This method has confirmed the suitability of previously used wood species, and has also suggested alternatives not considered thus far. Previous studies into the surface densification of wood have provided a rather sound understanding of the densification process and have provided a useful foundation for the current project. The work done, thus far, has shown the viability of a continuous densification process and has indicated a sensible path towards the widespread establishment of surface-densified wood products on the market.

Development of a new wood-based modular furniture system : evaluation of suitable materials for connectors

Concepts for modular furniture systems are of growing interest from the perspective of bothproducers and customers, and they are now entering the area of mass customization. Modularity andstandard interfaces eliminate the interdependency of the components of a product, and allow themanufacturer and customer to change components without affecting the product architecture. In thiscontext, the connectors between components of the modular furniture systems are essential for thesystems. The objective of this study was to evaluate the suitability of different wood-based materialsfor the connectors of the modular furniture system, the focus being on the strength properties.13different types of wood-based material were tested in three-point bending tests, and the modulus ofelasticity (MOE) and the modulus of rupture (MOR) were determined. The tested materialsincorporated wood modifications such as compression, heat treatment and impregnation, as well asdifferent types of adhesives. It could be concluded that birch plywood bonded with soybean glue, andsolid cumaru wood are the most suitable types of wood-based material for the modular furnituresystem. Compressed plywood generally exhibited better strength properties than ordinary plywood,and the type of adhesive had no significant influence on either MOE or MOR. Self-bonding plywoodhad a high MOE, but a comparably low MOR. Solid cumaru wood exhibited both a high MOE and ahigh MOR. Materials which had reasonable strength properties and a comparably low environmentalimpact were considered suitable for the connectors of the modular furniture system, which meant thatnon-formaldehyde-emitting adhesives were favoured.Validerad; 2016; Nivå 1; 20151225 (dicsan)</p

Development of a wood based modular furniture system

Godkänd; 2015; 20150929 (dicsan)</p

Development of a contiuous wood surface densification process.

Godkänd; 2015; 20150930 (dicsan)</p

Application of a new method to select the most suitable wood species for surface densification

Surface densification improves many properties of solid wood, and opens up new applications for low-density species e.g. flooring or wooden structures, and adds value to these species. Research into the surface densification of wood has been focused mainly on Scots pine, Norway spruce, aspen and poplar. In order to propagate the use of surface densification techniques, it is necessary to find more wood species that have a particularly high potential for an increase in value through such a treatment.The purpose of this study was to select wood species which are suitable for surface densification and for use in a specific product, by applying a systematic and quantifiable selection method. The method that was presented in detail in an earlier work, is designed around a workflow consisting of multiple stages, takes into account weighted selection criteria and provides a quantified ranking of the most suitable species.The results suggest that several species such as alder, basswood, cedar, and obeche that have not previously been considered for surface densification may be suitable candidates. Aspen, poplar and pine were confirmed as suitable, being among the top species in the ranking.Godkänd; 2016; 20160712 (dicsan)</p

Continuous Densification of Solid Wood – the Belt-press Approach

ISBN för värdpublikation: 978-609-02-1762-7</p