In 2006 Lafarge Plasterboard Australia sought a system integrator company experienced in handling the powders associated with the manufacture of stucco and plaster.
The choice included large overseas companies but evaluation led to Control Automation Pty Ltd, (CAPL) a division of Kockums Bulk Systems Pty Ltd (KBS) based on their experience and wide range of specialised products, for the many processes and the difficult flowing powders that are used.
Corey Gatt, the Lafarge Plasterboard Australia (LPA) Project Manager, was aware of the automated upgrade systems supplied by CAPL/KBS to Winstone Wallboards in Auckland New Zealand about 18 months previously.
Corey sought a company that could design an efficient layout for a greenfields site on an existing property, manufacture and supply fully automated equipment and act as project manager for installation and commissioning of a turn-key system.
Lafarge arranged for the building and tower structure separately, with a substantial design input from CAPL/KBS.
The critical factor was to enable a fast track supply to suit the expected demand for the product.
This was achieved as Corey Gatt for LPA working directly with the designer and integrator, CAPL/KBS.
The project officially started with the first sods being turned on the site in late April 2007. Commissioning commenced in February 2008.
Major ingredient raw materials arrive by bulk tanker which discharge into a nest of silos. Other products are delivered in bulk bags and some minor and micro ingredients are supplied in sacks.
The end product is packed in 10kg and 20kg sacks, and automatically bagged and palletised. The overall plant design rate is 8 tonne per hour.
There is also a liquid system to provide ready-mix compounds. The raw materials include some of the powders mixed from the dry system, and resins etc available in one cubic metre containers. The finished products are supplied in 20 kg tapered plastic buckets and manually palletised by Tawi hoist, at the design rate of 4 tonne per hour.
A wide range of product densities are handled, from sand to perlite and particle sizes ranging down to 10 micron.
Certain machinery items were nominated by LFA as part of their world standard supply, and CAPL integrated these items into the system.
The installation commenced with 4 silos up to 90 m3 capacity, that were lowered through the roof of the building.
These silos were mounted on a platform to enable screw feed to weigh hoppers. Other ingredients for the weigh hoppers come from pneumatic conveying receiver hoppers and IBC units that feed product to flexible wall feeders and into the weigh hoppers.
The weigh hoppers dump into dense phase conveyors mounted in a pit, to quickly send the product to mixers on the tower structure.
The tower structure is the location of the finished product delivery. At the base of the tower is the automatic bagging plant for the dry powders, and this feeds directly to the automatic robot palletising line. The liquid mixing and packaging system is also located at the base of the tower, where the pails are automatically filled, and in this case are manually palletised.
A bulk bag handling system and pneumatic conveyor is used for certain 'minor' ingredient specialised powders, to provide entry into the system.
The primary mixing and packaging tower accounts for the dry and the wet packaging outfeed. The product arrives at the tower from the dense phase transfer vessels under the main silo nest, and is fed to the bag and drum automatic packaging systems.
On another platform, sacks are added through a manual bag dump and into a mixer. This area provides for the 'micro' ingredients, via an IBC mounted under the mixer.
The fully automatic system is controlled by an Allen Bradley PLC and three SCADA controlled touch screen terminals. A very high level of automaton is used.
The operator decides on the formula at a SCADA, and sets a process in motion for an automatic product run, completely through to the bagged finished product, then automatically palletised.
CAPL/KBS supplied a system of world's best practice, using many in-house specialised components to maximise the utilisation of the plant. Extensive experience with handling difficult powders from proven knowledge, and a continual product testing regime ensured automatic product handling with minimum operator involvement.
In the early stages 'OH&S' and 'Operator Friendly' considerations bear heavily in the discussions for most ideal layout, as the system design is pieced together.
The use of low velocity dense phase transfer, and smart design techniques ensures the minimum power consumption through the various processes. Generous sized air filters are fitted to ensure dust is fully contained in the process.
Bags are automatically filled and fed to a palletising line which consists of a bag flattener, check weigher, de-duster, and printed with date etc. An automatic pallet dispenser, and plasterboard slip sheet dispenser feed the new pallet to the Okura robot operating area. When stacked, the pallet moves forward to the accumulation conveyor, ready for pickup by a fork truck.
From the Wet System, the filled buckets proceed to an accumulation conveyor, where an operator picks 4 or 6 buckets at a time with the VacuEasylift, to place the full width of a pallet at each drop.
Kockums PCVs are used for the dense phase conveying.
Posi-flate inflatable seat butterfly valves are used in the powder and air lines for long life.
The seat inflates against the valve disc allowing for wear take-up.
CAPL Autoflex Flexible wall screw feeders offer a high level of accuracy for the weigh mixes. The flexing wall ensures that product flows progressively, and completely to the metering screw. Variable speed control of the screw ensures a very high level of accuracy is obtained at the discharge into the weigh hopper.
CAPL Bulkaflo bulk bag dischargers are incorporated for 'minor ingredients'.
A hopper with rubber membrane for sealing around the bag to prevent dust escape, is installed in a lifting frame to enable the bulk bag to be inserted utilising a driven crane on a monorail. An air filter is used to capture any dust generated, and return it to the process.
The whole unit is mounted above a Midiveyor for conveying the product to the process locaton.
A Kockums Microveyor and Midiveyor are incorporated in the system, offering a compact pneumatic conveyor for working under bulk bag emptiers, to transfer product to an appropriate location.
A series of CAPL IBC Autobins and discharge stations are used for storing and transferring the mix of micro ingredients. This operation provides a mixed product in a fully sealed container, which, when installed on the discharge station, discharge directly into flexible wall feeders with full dust containment. The sealed nature of the container means product may be sampled and tested in batches.
A KBS Manual Sack tip for the micro ingredients is mounted directly over a 3000 litre mixer, which discharges into an IBC. The sack tip has a dust filter/fan system to contain the dust from the cutting operation and the refuse bags are dumped into a compactor, so keeping the dust under full containment.
Product is loaded into IBCs here, and they are transferred and mounted over the feeders in the batching area.
Three SCADA stations are used to drive the system, and enable choice of formulae and quantities and general operation levels of the system.
The plant is running very successfully at a high level of output, and is quite adaptable to changes of raw material characteristics, which assists when a new formula is being run.