School of Agriculture, Food and Ecosystem Sciences - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 19
-
ItemA Wood Recovery Assessment Method Comparison between Batch and Cellular Production Systems in the Furniture Industry(AMER SOC TESTING MATERIALS, 2019)Abstract Enhanced wood recovery mirrors a successful wood manufacturing operation. Studies of wood recovery in secondary wood processing, however, are scarce, particularly in furniture manufacturing. Although recovery rates are under the continuous surveillance of sophisticated technology, this attempt to monitor wood recovery would be especially challenging for small- to medium-sized furniture enterprises, as the capital investment in such technology would be substantial. This would hinder the possibility for improvements in production efficiency of the furniture industry. A methodology of wood recovery assessment in the furniture industry has been developed and proposed but has not been validated with a cellular production system, a different layout process and distinctive machinery, species, and other customer requirements. The objective of this study is to assess the wood recovery protocol individually used in batch and cellular production systems, followed by examining the wood recovery of furniture manufacturing in these distinct production systems. Two Indonesian medium-sized furniture companies that individually operate batch and cellular production systems were employed, and two methods, mass and volume, were used to assess wood recovery at each furniture-making station. There was a significant difference in cumulative wood recovery rates between batch and cellular production systems. Based on species and product dimensions, the average individual and cumulative wood recovery rates of furniture manufacturing resulted in a significant difference at the resawing and edging station. Large-dimension product recorded higher wood recovery level than small-dimension product. The wood recovery rates at the resawing and edging, surface planing, thickness planing, and trimming stations were mostly influenced by species, the quality of sawn timber, and cutting bills. Meanwhile, wood recovery at other stations was affected by product dimension and design. The mass method was the most acceptable method according to the measurement systems analysis.
-
ItemFurniture Production Efficiency in the Indonesian Context(International Conference on Wood Science and Technology, 2018-10-16)Most efficiency improvement strategies implemented in furniture manufacturing are data-driven methods. Due to a lack of production systems used in most Indonesian small and medium-sized furniture companies, the evaluation of production efficiency for future improvement seems rather difficult to perform. A wide range of existing evaluation tools and the varying capabilities of the companies to adapt the methods contribute to a problematic evaluation process. Research has been undertaken with the aim to develop a generic efficiency evaluation method and to prioritise a new potential metric to assess and control efficiency in furniture manufacturing. A basic production cost analysis with standardized variables has been demonstrated as a typical method to evaluate production efficiency in multi furniture companies, followed by applying a wood recovery assessment, a Pareto analysis, an X-Y matrix, and process capability analysis. The heartwood proportion of teak (Tectona grandis) has been determined as a key potential efficiency metric to control and monitor teak sawn board quality and its utilisation. Applying process capability analysis with a setting of lower specification limits to the population of teak heartwood rates produces a model to simulate optimal teak utilisation.
-
ItemQuality assessment of the drying process for Eucalyptus delegatensis timber using greenhouse solar drying technology(Springer Verlag, 2019-01-24)The aim of this study was to investigate the process of drying Eucalyptus delegatensis in a greenhouse solar kiln. Specific objectives were to assess stress formation, moisture gradients and timber distortion, the moisture content distribution within various sections of the timber stack, and internal checking and collapse development within the boards. The maximal temperature and relative humidity (RH) during day time were set at 430C/72% RH. In the night time the temperature was at ambient condition with 90% RH. The strain measurements were undertaken before and after the samples were sliced. The timber quality at the end of drying was assessed based on Australian and New Zealand standard (AS/NZS 4787:2001). The moisture content values in the three different sections (front, middle and end) of 2400 mm long boards were compared by Analysis of Variance. The results showed that the mean compressive strain was -2 x 10-4 mm/mm in the core layers and the tensile strain was 14 x 10-4 mm/mm in the outer layers. All sample boards were within the acceptable limits for cupping, spring and bow, even though the relative humidity level did not reach the set value. However, the amount of twist in three out of twelve sample boards was above the acceptable limit. Mean moisture gradient was 0.6%. There was a significant difference in moisture content at end section compared to the front and middle sections. Internal checking, collapse and residual stress were graded as Class “C” (class A is the highest grade and D is the lowest).
-
ItemDrying timber in a solar kiln using an intermittent drying schedule of conventional laboratory kiln(Taylor & Francis, 2018-10-01)The purpose of this study was to apply an intermittent drying schedule developed from a conventional kiln to a solar kiln. Implementing this experiment could help better understand the oscillation of the temperature inside a solar kiln and timber quality during drying progress. The theoretical recharge and discharge curves were used to predict the temperature inside the solar kiln using experimental data obtained previously using a solar kiln. The surface and internal checks were measured using ImageJ freeware, and the development of the Moisture Content (MC) profile was assessed by coring and slicing method for the Eucalyptus delegatensis boards during drying. The results showed that the recharge and dis-charge model can predict the temperature with less than 2 C error from the experimental data in the solar kiln. The total drying time to 12% MC was 87 days for the solar kiln. The drying rate was equivalent to the conventional kiln decreasing at an average rate of 0.2%per day. The surface check formation was found when the MC gradient between the core and the case of the board was greater than 42% at 9 days of drying in the solar kiln and conventional laboratory kiln. The applied drying schedule used in the solar kiln was success-ful and offered similar drying time. However, the oscillation of temperature in the intermittent drying will require further improvement to get closer conditions in a solar kiln.
-
ItemPotential of Veneer Peeled from Young Eucalypts in Laos(North Carolina State University, 2018-08-23)In Laos and neighboring countries, opportunities exist for the production of engineered wood products such as plywood and laminated veneer lumber to supply the rapid growth of construction, furnishing, and joinery activities. The objective of the present study was to assess the potential of peeling fast-growing high-yielding pulpwood from managed eucalypt stands in Laos for veneered products. Eucalyptus pellita, Eucalyptus camaldulensis, and eucalypt clone K7 (E. camaldulensis × E. deglupta) stands were characterized based on veneer quality and recovery. The influence of log position, log geometry, and other log traits during recovery were also investigated. The selected taxa achieved green veneer recoveries that ranged between 57% and 67%. End splitting and branch-related defects were the most important grade-limiting defects that restricted veneer sheet quality to a lower grade of most sheets. However, simple timely silvicultural decisions, such as pruning, could significantly help improve the quality of veneer obtained. The obtained results could be used in the formulation of recommendations to adopt better management practices in Laos to improve the value of plantation-grown wood.
-
ItemAchieving Long-Term Adhesion and Bondline Durability with difficult-to-bond Australian Hardwoods Species(Society of Wood Science and Technology, 2018-07-25)Australia has unique resources of native hardwoods producing a range of aesthetically and structurally attractive timbers suitable for high-strength structural applications and other products for internal and external applications. Amongst problems limiting broader hardwoods applications is their excessive susceptibility to hydrothermal movements in response to changes in the atmospheric moisture. This, in turn, produces excessive interfacial stresses between hardwood surface and glues, resulting in fast degradation of adhesion in products exposed to weathering. A range of Australian hardwood species also suffers from poor adhesion due to high bulk phenolic and surface lipophilic extractive content as well as high density. Research has been undertaken with the aim to improve the performance, durability, and designs flexibility of hardwood-based components for outdoor and indoor applications. The method relies on the application of eco-sustainable water-based formulations of functional polymer and chemical additives overcoming the impact of extractives and facilitating chemical bonding of designated connector chains to cellulose constituents. To date, results of adhesion bonding tests have demonstrated a significant increase in shear strength, wood failure, and durability compared to unmodified samples of Eucalyptus camaldulensis, Eucalyptus pilularis, and Eucalyptus regnans. The results could potentially facilitate the effective transformation of the housing and construction industry by targeting drastically increased use of hardwoods by the rapidly developing Australian prefabricated housing and construction industry.
-
ItemNo Preview AvailableTechnical Report for Maton Guitars( 2018-07-17)The present report outlined below forms part of ACIAR project FST/2016/151 – Advancing enhanced wood manufacturing industries in Laos and Australia. As part of the project, the University of Melbourne (UoM) and Department of Agriculture Fisheries (DAF) project staff work with Maton Guitars (MG) on various R&D areas nominated by MG that align with the objectives of FST/2016/151. Overall, the main research focus is on enhancing kiln drying efficiencies and utilisation of alternative species in their guitar manufacture. MG has identified the following specific sub-project as a high priority: Improving kiln drying efficiency and best practice. This will include assisting in setting up best practice drying for new kiln investments and running drying trials to improve drying efficiency and consistency. The report presents the results of moisture content profile and residual drying stress tests. The tests were conducted on blackwood (Acacia melanoxylon) resawn billets taken from a batch which showed distortion. The ACIAR team conducted detailed moisture gradient testing and residual drying stress tests of 5 billets.
-
Item
-
ItemA Proposed Method and Its Development for Wood Recovery Assessment in the Furniture Manufacturing Process(NORTH CAROLINA STATE UNIV DEPT WOOD & PAPER SCI, 2018)A proposed method for assessing wood recovery involves the application of a machining station approach with volume and mass measurements. A medium wood furniture company located in Jepara, Indonesia was selected to develop the method. Batch measurements of the inputs and outputs for different types of indoor-furniture products at every station were collected and analyzed. For the volume method, three dimensions were measured on each specimen: the length, width, and thickness. For the mass method, the specimens were weighed before and after each processing station using a balance. Based on the mass method, the average total wood recovery rate was 26.2% ± 2.3%. For individual products and per station, the significant difference in the wood recovery rate occurred only at the resawing and edging, and trimming stations. The relationship between the teak quality, product dimensions, and type of finish was significantly different, where A-quality teak, large dimensions, and polyurethane finish resulted in a higher wood recovery rate. Both methods were reliable because of insignificant differences in the wood recovery rates. However, the mass method was more efficient and practical. The proposed protocol using the mass method is a suitable and effective system because the contribution of the variance component of the method was 2.71%.
-
ItemComparing two intermittent drying schedules for timber drying quality(Taylor & Francis, 2018)Intermittent drying techniques for drying timber may provide various benefits by improving timber quality and addressing energy efficiency through saving in energy consumption. The purpose of this study was to compare two intermittent drying schedules applied in the treatment of Eucalyptus delegatensis boards, through assessing surface and internal check development, moisture content (MC) profiles during drying, and timber distortions at the end of drying. The study used identical conditions during the heating phase at 45°C/60% relative humidity (RH), except for RH during the nonheating phase (80 and 90%). The results, discussed in this paper, analyzed the timber quality during and at the end of drying. The different RH during the nonheating phase did not generate a significant difference in MC at the case boards between the two drying schedules. The assessed quality of timber at the end of drying was based on AS/NZS 4787:2001. MC gradient, drying stress residual, internal checking and collapse were graded as class “A” (class A is the highest grade and D is the lowest). Bow, cupping, and spring were under the permissible levels based on grading standard AS 2082–2007. Measured data were validated using Drytek® simulation software showing MC movement in case boards.