OH&S News

Mobile screen caters to the ‘green thumb’ market

Searles Garden Products is a family-owned Australian company, based in Kilcoy, Queensland, 98km northwest of Brisbane. Its 4700 products include potting mixes, fertilisers, mulch, seeds, weeding, pest and disease control goods, garden accessories and corflute signage.

These products are distributed across Australia through numerous stockists, including independent art and garden centres, nurseries, local timber, hardware and interior design stores, agricultural supply traders, concrete and landscape businesses (including notably Mawsons Concrete & Landscaping in Victoria), and large hardware chains such as Bunnings and Mitre 10. There is a very strong chance that you will have bought a Searles product on your visit to your local garden centre or hardware store.

The company was founded by a husband and wife team – Con and Jenny Searle – in 1977 at Caloundra, on the Sunshine Coast, and originally sold a mere five products that were supplied in clear plastic bags with wire tied tops to household gardeners. The business at the time was merely equipped with a ute, a shovel, a wheel barrow and a cement mixer.

It wasn’t until 1979 that the Searles’ business really took off, as they started supplying products to garden centres and nurseries along the Sunshine Coast. By the mid-1980s, the couple’s sales had expanded to Brisbane, central Queensland, the Gold Coast and northern New South Wales. In 1985, they formed the family company JC & AT Searle Pty Ltd.

In the late 1980s, Searles Garden Products became the distributor of a wide range of home gardening products and its sales expanded to encompass the rest of Queensland, the NSW north coast (from Tweed Heads to Newcastle), western NSW, and Darwin. The expansion meant the company had to move from its original base in Caloundra, and eventually in the 1990s, the Searles purchased the current Kilcoy site, which was customised and constructed to the company’s specifications and features advanced production, research and distribution facilities. It is located along the D’Aguilar Highway and employs 75 staff, with expertise in administration, sales, research and development, production, warehousing and distribution.

Ashley Searle, one of the two sons of Con and Jenny Searle, is the company’s technical manager and leads a modern on-site laboratory with a highly skilled team of university qualified research staff. The laboratory continuously monitors, trials and quality tests its products, with a particular emphasis on the development of high quality goods in the composting and blending process.

To quote the Searles Garden Products website: “With our composting and blending expertise, we are able to produce products, which contain specific amounts of composts, humus, humic colloids and microbial life that can enhance the product beyond comparison … These nutrients are available for immediate use by the plant and they can also be stored for later use as the plant requires more … The end result is improved plant growth, improved plant health and a robust, flourishing garden!”

The compost products are “superbly enhanced” by specialised additives, including Penetraide re-wetting granules, controlled release fertilisers, soluble plant foods, water crystals, coir peat and peat moss, and zeolite, trace elements and other minerals.


Mobile screen acquisition

As a result of this commitment to producing the highest quality garden products, Searles has utilised heavy-duty quarry-spec gear. It has for several years screened its compost materials using screening plant and equipment supplied by the Lincom Group. Its purchases in the past have included a Pronar trommel and a Powerscreen Chieftain 2100X mobile screen three years ago. Searles has never needed to purchase mobile crushers to process already fine materials.

Now, Searles has swapped its Chieftain 2100X on a “like for like” basis, receiving the latest generation model in exchange for its original machine. The Chieftain 2100X has been screening 40mm of mulch on its top deck and 12mm to 16mm on the bottom deck. Due to contaminants in the raw materials, the screen generates three stockpiles, two of which are waste products (40mm + 20mm), while the third is the end 12/16mm product which goes into the potting/mulching mix bags.

“Searles bought its screen for its 12/16mm product, which is the end product of processing 60mm to 70mm materials,” Davy McDermott, Lincom’s area sales manager for northern NSW and southeast Queensland, said. “The 2100X is good because it’s a 20’ x 5’ (6.1m x 1.5m) unit that provides good product splits – to get the full efficiency of the big deck. Searles doesn’t have to screen the material twice, it’s doing it all in one hit.

“Originally the company expressed interest in the Chieftain 1700 which is only a 16’ x 5’ (5m x 1.5m) unit. They stepped up to the 2100X, which gives them a clean finished, screened product. The bigger the screen, the better the quality of the stockpile.”

The Chieftain 2100X twin-deck incline screen at Searles was bought primarily for the recycling of top soil and the processing of composted materials. However, it is also suitable for a range of other applications, including aggregates, sand and gravel, blast rock, river rock and overburden, and can also process C&D materials and other by-products including foundry materials and processed minerals. The 2100X is designed for medium to large scale operators that require large volumes of high specification products.

The 2100X features an 8m3 feeder hopper with 300mm extensions, a standard adjustable angle reject grid, a heavy-duty, single-shaft incline screenbox with adjustable stroke, angle and speed, a 5.5m top deck and a 1.5m bottom deck, and a drop-down fines conveyor to assist with bottom deck mesh access. It is equipped with main, tail and side conveyors that provide stockpile discharge heights up to 5m. The hydraulically folding conveyors provide for easy transport; the 2100X has heavy-duty, low ground pressure tracks that in turn can be guided by a pendant remote control system.

Depending on media sizes and material types, along with the installation of some options, the Chieftain 2100X can at full capacity provide a maximum throughput of 600 tonnes per hour (tph) for a quarrying producer.

“For that amount of tonnage, you’d require a 100-200mm mesh top deck and a 50-70mm bottom deck,” McDermott said. “Realistically, a producer would have a turnover of 1500 to 2000 tonnes per day, and be producing 5mm, 7mm, 10mm, 14mm, 16mm and 20mm products for asphalts and concretes. They’d also have to be using cone and jaw crushers in their mobile circuit, and have different types of meshes for six different products. On average, the Chieftain 2100X is more likely to produce in the range of 200 to 250 tph for the average quarry producer.”


Optional features

One of the options available to buyers on the 2100X is a double-deck, remote-controlled tipping grid option, with a 152mm (6”) grid aperture between each bar, a discharge chute and a crusher feed chute. McDermott said the advantage of the tipping grid is that it can be tipped to 90 degrees and runs like a screenbox. “Instead of relying on the feeder all the time, the grid runs off the screen. You can also install a mesh on the bottom deck and control what feed goes to the screenbox. You would use the grid for a gravelly type of rock, like a river gravel of 300mm – 60-300mm. River gravel is very round, so the sand is very good for decorative stone products.”

McDermott said the advantage of mobile screens like the 2100X is that the angle of the screenbox can be adjusted from 20 to 30 degrees, making it ideal for a range of applications, from compost to sand and gravel. It is also possible to use a variety of different screen meshes, including 100mm mesh, polyurethane, mats, aggi-vibes, 100mm coated mesh, and a guitar wire with adjustable gaps up to 3mm. Producers also have the option of purchasing a self-cleaning flexi-mesh for the bottom deck which McDermott said is “very good for sticky materials, to avoid the mesh blinding over. You get really good screening efficiency and you’re not having to clean the mesh all the time”.

The Chieftain 2100X is powered by an 83kW Tier 3 Caterpillar C4.4 diesel engine at 2200 revolutions per minute for the two-deck unit. Australia currently uses Tier 3 engines but Powerscreen is gradually installing Tier 4 Final engines on all of its mobile crushers and screens. McDermott added that there is also a dual power diesel/electric option for the Chieftain 2100X, featuring two electric motors.

“Dual power has been out for a while, and is a significant part of Powerscreen’s – and Lincom’s – screening options,” he said.

There is also the option of a triple-deck version with adjustable screen speed and amplitude and hydraulic screen angle adjustment. The three-deck 2100X features a hydraulically folding recirculating conveyor, with a 4.4m discharge height, which eliminates the need for the two-bearing screen.

For Searles, the two-deck screen version, though, has “worked a treat”, according to McDermott. “Searles found the new 2100X much quieter than the previous one,” he said of his client’s feedback. “There’s been improvements with the engine canopy, which is more sound-based and the muffler on the exhaust has also been redesigned. It is also processing a softer material, of course.”

McDermott said the compost “screening process” has sufficiently removed material and wood chips from the 16mm end product, and the resulting compost is “light, fluffy, and easy to handle”, making it immediately ready for market all over Australia.

In this publication, we never stop emphasising just how integral the aggregates and other primary industries are to the everyday products that underpin our social infrastructure. Next time you pick up a premium compost or platinum potting mix, or an organic or soluble fertiliser for your garden, remember that there’s a very high probability it is a Searles gardening product and it’s been processed by a quarry-spec Chieftain 2100X screen.

The Lincom Group is headquartered in Brisbane, with offices and warehouses in every state and territory, New Zealand, Papua New Guinea, New Caledonia and other Pacific Islands. In addition to the Powerscreen range of mobile plant and equipment, it is also the distributor of sand and aggregates processing equipment, filter presses, stackers and mobile conveyors, mobile and fixed plant trommels, and static and mobile recycling plants.

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