Located in the industrial area of a Brisbane suburb, Mayco Industries Pty Ltd (Mayco) manufactures kitchens for residential and high rise markets. Their factory is one of the largest in Queensland, producing between 35 and 55 kitchens per week, and employs 86 staff, 20 of which work on a casual basis.
Both natural timber and manufactured board are used by Mayco to manufacture kitchens. Therefore, both timber dust and manufactured board dust are generated in the manufacturing process. Dust from manufactured board cannot be reused or recycled at present, due to the presence of formaldehyde, which is a constituent of the bonding agent that is used to produce the board.
Traditionally, woodworking factories dispose of both timber dust and manufactured board dust to landfill. For Mayco, the costs associated with this disposal were quite substantial due to the large quantities of dust generated. Twelve years ago Mayco installed a dust extraction system that allowed them to separate the two dust streams. By segregating the timber dust from the manufactured board dust, they were able to find markets to receive the timber dust, significantly reducing the amount of dust disposed to landfill and subsequently reducing disposal costs.
The timber and manufactured board dust is extracted from the working area via a vacuum ducting system. Inlets of the extraction system are located at the stations where the wood is processed, as well as by the floor, to capture fallen wood particles. The timber and manufactured board kitchens are manufactured in separate sections of the factory. This allows for logical arrangement of the extraction system which then transports the dust to one of two cyclones. Cyclones operate under a centrifugal system which extracts the dust from the air stream. The dust is then collected and stored in hoppers. One cyclone system collects the timber dust, while the other cyclone system collects the manufactured board dust.
The dust is hauled off-site by a private contractor on a fortnightly basis. The loading facility at the hoppers and the contractor’s truck have been designed to allow the transfer of dust from the hoppers with minimal loss of dust to the atmosphere. The contractor transports the timber dust to chicken farms and horse stables. The manufactured board dust is hauled to one of BCC’s waste transfer stations for ultimate disposal to landfill.
Changes Made and Savings
Reduced Disposal Costs
- Approximately 93.6 tonnes of manufactured board dust and 98.3 tonnes of timber dust are generated by Mayco every year. The costs involved with the disposal of the dust include landfill charges ($55/tonne) and haulage charges ($35 per truckload).
- Two truckloads of dust are hauled every fortnight, one of manufactured board dust, the other of timber dust.
- Manufactured board dust, which can only be disposed of at the landfill at present, costs a total of $6,110 per year ($5,200 for disposal and $910 for haulage).
- The cost of disposing of timber dust to landfill would be $6,317 per year ($5,407 for disposal and $910 for haulage) if segregation were not possible.
- The cost of disposing of timber dust at chicken farms and horse stables is $910 per year for haulage.
Approximate savings from reduced disposal costs are $5,407 per year, as outlined below.
- Disposal and haulage costs without segregation =$6,110 + $6,317 = $ 12,427
- Disposal and haulage costs with segregation =$6,110 + $910 = $ 7,020
- Saving = $ 5,407
Costs and Payback
The costs involved in establishing a dust separation and collection system could be in the low to mid $10,000’s. Costs are dependant on the size of the premises, and whether or not the system is to be retro-fitted or installed when the premises are under construction. It is expected that retro-fitting would be the more expensive of these options. Smaller premises may find the use of bag houses to be more cost effective than cyclones.
The maintenance costs of the system are low, approximately $100 per year. Direct cost savings made as a result of this project are $5,407 per year, associated with the avoidance of landfill disposal costs. Based on an estimated installation cost of $20,000, the payback period would be approximately 4 years.
The installation of the dust collection systems has created a dust free workplace, which enables management to ensure compliance with workplace occupational health and safety standards.
Mayco have considered extracting the formaldehyde from the composite board dust to produce fireplace briquettes by compacting the dust. However, it has been determined that this process is not cost effective at this stage.
Other waste management systems have recently been instigated, including a solvent recovery and recycling facility and waste paper and cardboard recycling.