Last year the US furniture market alone has produced a revenue of $304 million, demonstrating that the furniture industry has had – and will have – an excellent performance from year to year. At the same time, however, statistics show that 300,000 tonnes of reusable furniture is thrown away in the UK annually. Is this sustainable? Absolutely not. As wood is the most common source for furnitures, we have to evaluate and re-think alternatives such as Arundo-based furniture.
Arundo-based furniture: Arundo as a non-woody plants for industrial applications
Global brands are committed to science-based targets, which aim to help limit global warming to well below 2 degrees Celsius – the goal set in the 2015 Paris agreement. IKEA, the world’s biggest furniture retailer, plans to use only renewable and recycled materials in its products by 2030, to reduce its impact on the environment. For that reason, high-end furniture does not have to be made from hard-wood, in fact, more efficient alternatives are taking over the market (Figure 1). In the last decade, European agricultural research has focused much attention on the search for new, non-food crops with regard to their industrial utilisation. Arundo donax (further on Arundo, but also known as “giant reed, giant reed grass, giant cane, reed cane, giant tropical plant, Spanish reed”) has been considered as one of the more-promising crops.
Arundo-based furniture: Minimizing environmental impact
Arundo (Figure 2) is a perennial, fast growing plant in grasslands and wetlands. By applying Arundo for alternative non-wood based material, it helps to reduce the high dependence of imported wood timber and boards by using a readily and annually renewable resource. Moreover, industrial applications are economically justified because of the low cost of biomass production and the high plant productivity.
The production of particleboards starting from Arundo represents another interesting application.
Arundo-based furniture: Particleboard
Particleboard is a composite product manufactured under elevated pressure and temperature from particles of wood or other lignocellulosic fibrous materials and a binder (EN 309, 2005). Particleboard is widely used in furniture, where it is typically overlaid with other materials for decorative purposes. It is the predominant material used in ready-to-assemble furniture, flooring systems, manufactured houses, and underlayment.
García-Ortuño et al. and Flores et al. used particles from Arundo culms with different particle sizes as a raw material for particle board panels (Figure 3), and suggested that producing high-quality Arundo-based particle board is feasible. Since particleboards produced with particles of sizes (Figure 4) from 1 to 2 mm and 1 to 4 mm had the most desirable quality. So the production of such sizes is recommended for the milling of the culms.
Arundo-based furniture: Quality of Arundo-based particle boards
Arundo particleboards, manufactured under the suitable pressure and with appropriate resin proportion gave very good results.
Flores set up the following groups for comparison, results are summarised in Table 1.
- Block board
- Rough Board: reed-particleboard developed using the rough material obtained from a hammer shredder.
- Standard board: reed-particleboard developed with 4 mm sieve.
- Optimal board: reed-particleboard developed without 4 mm sieve.
- Gold-standard board: an equivalent standard wood-particleboard was used as a benchmark.
Table 1: Board properties and mechanical results. Density, MOR, bending test, and MOE
|Board type||Density (kg/m3)||MOR (N/mm2)||Bending test (mm)||MOE (N/mm2)|
|Block board||463.28||3.658±0.421||8.039±0.408||976.3 ±152|
Results (Table 1) showed that the industrial boards reached a higher density 696.21 kg/m3, against the 612.14 kg/m3 of the Optimal Board and a Modulus of Rupture (MOR) of 15.98 N/mm2, compared to 10.28 of Optimal Board. It is remarkable that Rough Reed Particleboards present lower quality in terms of bending parameters. Standard and Optimal Reed Particleboards have similar behaviours, with a slightly better performance for the optimal type. The highest Modulus of Elasticity (MOE) was reach using the optimal board, with 6.49 mm deformation; which was well below the reference. An increasing performance (density, tensile strength and modulus of elasticity) was observed as particles sizes decrease, reaching optimal values for 2 and 4 mm.
Table 2 compares different materials (manufacture in a single layer dry), published with different production method. In relative terms, Arundo provided a significant better performance especially in terms of MOR, where figures were from 2 to 10 times higher than Spruce wood, Sunflower stalks, Topinambur stalks, Mischanthus.
|Material used/board type||MOE (N/mm2)||MOR (N/mm2)|
|EN 312 type P2||1600||13.0|
Interestingly, the physical properties (such as internal bonding, thickness swelling, modulus of rupture and elastic modulus) of Arundo-based particle board were even better than those of wood-based particle board. However, the modulus of elasticity (MOE) (up to 1362 N mm-2) and modulus of rupture (MOR) (up to 10.3 N mm-2) of Arundo particle board did not meet the UNE 312-4 thresholds (MOE of 1600 and MOR of 13 N mm-2). Thus further investigations for improving its mechanical properties were needed.
The same scientist one year later published a paper that has proven, Arundo particleboard panels provide an important resistance to water. Compared that of any wooden particleboard, revealing its clear competitive advantage for certain uses, e.g. in high humidity environments without the need for special resin or waterproofing process.
Arundo-based furniture: Environmental friendly particleboard
Since most applications are interior, particleboard is usually bonded with a urea-formaldehyde (UF) resin. However, in the European Union, formaldehyde is considered a high-priority pollutant, and also the International Agency of Research of Cancer (a World Health Organization subsidiary) recommended to moderate the amount of urea formaldehyde resin content. Therefore, there is much interest in developing more environmentally friendly adhesives.
To meet these expectations panels of Arundo particles were produced using different non-modified cereal flours and native starches as binders without the addition of chemicals by hot pressing at low pressing temperature and pressure (Figure 5).
- Particleboards obtained with a 10% of potato starch and two pressing cycles met the requirements for general uses and indoor fitment, including furniture manufacture (in dry ambient).
- Panels made with corn starch and wheat flour met the standards for general uses (in dry conditions).
- Particles were not pre-treated, the starches were not modified, and the pressing conditions were very low; this method can be considered to be a low-cost procedure to manufacture environmentally friendly particleboards.
Arundo-based furniture: High mechanical performance boards
In a recent study fibreboards (Figure 6) with high mechanical performance from Arundo were obtained without any added adhesives.
The board production process followed these steps:
Arundo → Hydrolytic pre-treatment (200°C, 9,5 min) → Washing and Drying → Milling → Cold-pressing → Climatic chamber at 20°C, and 65% relative humidity → Hot-pressing (MDF/HDF).
As a result, by applying a steam explosion pre-treatment followed by hot pressing, Arundo is suitable for the production of fibreboard panel. Boards were classified as high density board (HDF) since the density were above 800 kg/m3. Thus high mechanical performance boards could be obtained without the use of external adhesives.
Table 3 shows production parameters of obtained panels. MOE, MOR and IB values in each setting, except one setting at the lowest pressing pressure (0,35 Mpa) were beyond that is required by standard UNE-EN 622-5: 2010 for structural boards. TS value was the maximum that is allowed by the standard.
MOE and MOR were significantly influenced by pressing pressure (Pp). The higher (Pp) lead to higher MOE and MOR. The TS and WA values had a high dependence on Pp. Increasing Ppresulted in boards with lower TS and WA values. TS values observed also largely exceed the requirements in the standard, while WA values were below the required 30% except one setting at the lowest pressing pressure (0,35 Mpa).
Table 3: Production parameters and characteristics of fibreboards made from Arundo
|Parameters||Tested values||required by standard (UNE-EN 622-5:2010)|
Arundo-based furniture: Plywood
Recent refinements in resins and techniques for plywood production, improving cost efficiencies, are directly transferable to Arundo layering. With the innovation of adding cost-efficient nanoscience technology and materials to substantially enhance fire retarding qualities, Arundo suitable for plywood production are poised to have a significant impact as the next generation of structural building material for sustainable development.
The invention of theUS20070125446A1 patent contemplates a method for making virtually fireproof plywood and dimensional lumber products from Arundo by employing nano-science materials (specifically potash) to be mixed into the resins used for binding the layers of the ply-board and board-like products together.
A primary objective of the invention is to provide an improved method for making an environmentally agreeable structural plywood that satisfies the need for sustainable, highly fire-retardant and insect-repellent materials for the building construction industry, thereby lessening dependency on building products made from trees.
Another objective the inventors contemplate is to provide an oriented strand dimensional lumber product such as the standard American 2×4’s and 2×6’s, etc. with all of the inherent advantages of Arundo.
The combination of both structural board and dimensional lumber made from green materials utilizing this innovative method meets the objective of the inventors to provide a “total green” building system.
These materials are ultimately designed as structural board and dimensional lumber products, but may also be used for other construction purposes which are non-structural in nature and in various other industries where they may be beneficial. An example is the marine industry because the raw stock of Arundo is highly water repellent.
Yet another objective of this invention is to provide a cost effective material superior in performance to wood for the manufacture of engineered building products such as I-beams, laminated beams, roof truss and forming materials for concrete.
Still another objective is to satisfy the need for long-lived building and consumer products such as non-structural panels for wall dividers, temporary dividers, cabinets, countertops, cutting boards, furniture, shelving, tabletops, packaging and crates, pallets, window frames, furring materials and finish flooring panels for decoration.
Arundo-based furniture: Infinity Board TM
By the use of US20070125446A1 patent a product called Infinity BoardTM(Figure 7) was invented.
Main properties of Infinity BoardTM
- 3 times lighter and stronger than conventional plywood and OSB (oriented strand boards).
- Waterproof – ideal for marine use
- Insect proof – especially wood destroying insects, and highly fire resistant.
- Less expensive to manufacture than plywood and OSB products.
- Adaptable for manufacturing of dimensional lumber and furniture making
Table 4 summarizes the laboratory test results and how they compare to the currently used structural wood-based materials such as plywood and OSB.
Table 4: Characteristics of Infinity BoardTMand compared to conventional plywood and OSB
|Modulus of Elasticity (psi)||1,142,000||Typical 600,000 – 800,000||~1,000,000|
|Modulus of Rupture (psi)||9300||3000 – 8000||3,000 – 5,000|
|Stiffness, EI (lb-in2/ft)**||34,500||34,000||–|
|Strength, FbS (lb-in./ft)**||635||185||–|
after 24hrs %
|7||6 (Douglas Fir)7.8 (Southern Pine)||10 – 15|
after 24 hrs %
|23||48.9 (Douglas Fir)58.3 (Southern Pine)||49|
|Moisture Content %||4||9 (Douglas Fir)9.4 (Southern Pine)||7-9|
|Vapor pressure soak||67||—||100-115|
Arundo-based furniture: Patents
- The method for the manufacture of Arundo particleboards was patented as “Method for Producing Hardboards from Giant Reed and Resulting Boards”, WO/2008/107504 (Flores-Yepes et al. 2008), and it is in commercial use through established contracts between patent-holders and commercial companies.
- The method for producing composite panels and pulp, and paper products of the pulp, from Arundo was patented as “Arundo donaxpulp, paper products, and particle board”, EP1115942A1.
- A method of producing a virtually fireproof plywood from perennial grasses such as Arundo was patented as “Method for Making Plywood and Dimensional Lumber from Arundo Donax L. or Bamboo”, US20070125446A1.