Grainswest - Tech 2022

Tech 2022 Grains West 24 HOW IT’S MADE Farkash took up recycling plastics as a serious side project after an acquaintance made an offhand comment about the need to save agricultural plastic from the dump. He will use grain bags donated by three nearby farmers to produce his first commercial fenceposts. A short distance from his invention, heaps of the rolled black-and-white plastic bags are stacked next to rows of used wooden pallets. These pallets are the fuel source for the machine and are sourced from nearby retail businesses. A metre in diameter, several plastic rolls were lined up on a conveyor, still under construction. Once complete, it will tip the plastic bales into a breech in the central barrel, a four-metre length of new oil pipe Farkash bought at a salvage sale. Dirty plastic cannot typically be used in post making, as grit dulls the blades used to cut the plastic. This is not an issue with Farkash’s machine, which has no cutting tools. Owing to their dark colour, impurities are not visible and do not affect the structural integrity of the post. The machine’s central pipe is heated by a pair of furnace tanks attached beneath it. These are fuelled with whole wooden pallets inserted by forklift. The fires are fanned so the hardwood frames burn clean. As the temperature climbs above 200 C, the plastic in the pipe above liquifies. In 1,100-litre batches, it is forced down the barrel. This is done by means of a device known as a PIG, which is pushed by a hydraulic ram. An acronym for “pipeline inspection gadget,” such devices are used to move residual oil down pipelines and may look something like wheeled beer kegs. This PIG moves on rollers and is tipped with a rubber membrane that seals the pipe and builds internal pressure that extrudes the plastic out the bottom end of the machine. Mounted on a carousel, a series of tubular steel moulds swings past a single extruder nozzle. Each in turn is filled with liquid plastic and submerged in a water tank. The temperature change causes the plastic to shrink away from the wall of the mould slightly. As the moulds emerge from the water bath, a high-pressure air nozzle swings into place at their pointed end and neatly shoots the finished post into a waiting basket. This catcher unit then stacks the finished posts in a metal-framed rack. Farkash demonstrated the process with a post he’d made earlier. The seven-foot posts are 4.5 inches in diameter and the colour and texture of a hockey puck. They are cylindrical in shape with a pointed bottom end. Farkash monitors the process from the comfort of an air conditioned control shed. Adjacent to the mould carousel, the brown-panelled building features a smooth, white control panel with levers and switches labelled by hand in black permanent marker. This is positioned below a large window and a video monitor that displays a series of camera angles that encompass the entire fencepost maker. As he leans back from the controls in an repurposed car seat, Farkash adjusted his red-checkered welder’s cap and crossed his arms as he recalled the three years of hard work he has put into this machine. A previous prototype used a A newly constructed conveyor will load used plastic grain bags into the fencepost maker. These are then liquified in 1,100-litre batches. FEATURE