Conveying a new message
September 1st 2005 Here IP&E reports on how garment conveyors are eschewing trolleys and automation
Overhead conveyors come in many guises and even those specific to garment handling, now a large market segment, use various systems that require careful thought before purchase.
The wrong choice could lead to higher initial and running costs, unnecessary damage, and numerous accidents from falling trolleys. According to the Finnish company, Salpomec, which invented Magic Tube, the world's first trolley-less conveyor system, accidents with trolleybased systems are now a big money issue, especially in America.
In Britain, at any rate, there now seems a clear trend away from automated, overhead hanging garment conveyors towards much simpler, cheaper and safer manual or trolley-less systems, like those from Salpomec and Red Ledge's Genus system. Other methods, whether chaindriven or based on motorised, rotating tubes, use trolleys and motors that take up far more space than manual systems.
They are also heavy on maintenance costs and downtime and in the case of chain-driven systems, which stretch and brake, could need total replacement every 10 years.
A quick checklist shows why automated hanging garment systems seem to be losing favour:
- High capital cost (driven lines, motors, etc.)
- High cost of trolleys and higher, all round, maintenance costs.
- Skilled maintenance technicians required
- Holding of expensive spares parts
- Sensitive to lesser efficiency owing to downtime when parts failure occurs
- Chain driven systems come to a complete halt if drive fails
- Need empty trolley buffers that take up storage or processing space
- Relatively expensive intake and dispatch booms
- Empty trolleys have to be delivered to intake using up the capacity of the driven system
- Empty trolleys are required in the picking aisles (pickers waste time searching for trolleys)
- Even in systems that have "captive" trolleys, they can still fall off, which can injure and damage personnel, garments or flooring
- Systems require temporary buffers after intake or before dispatch, where garments may stay for much of the day or night. This ties up significant trolley numbers
- Much harder to adapt the changing business needs.
Manual overhead conveyors may require manual intervention to move slugs of hanging garments but they will integrate with powered conveyors or vertical lifts to raise garments to any required level and then use gravity to descend to lower levels. In the Magic Tube's case, this is helped by a specially coated tube rail.
Even when fast sortation is required, there is no need for trolley-based systems. Red Ledge's Genus system, for example, uses a flight mechanism rather than trolleys for product motion and can still sort at up to 7 200 garments an hour.
It also has several unique aspects, says a Red Ledge spokesman, like delivering garments either side of the conveyor sorter, with twice as many diversionary gates in half the rail length of more costly rivals' systems. This means that, compared with other sorters, it can cut the footprint needed by half and so significantly cut building and manning costs. No mother hooks and trolleys are needed and it can take any plastic or metal hanger. Unlike rotating tube conveyor systems, it will raise garments up at least a 45 deg incline, and owing to its small headroom will fit under any mezzanine.
Having an IT background, Red Ledge has also ensured that Genus has a high level of conveyor intelligence, which allows sections to be networked so that they can learn from each other. The system will scan barcodes or radio data tags at front, back or sides with 100% accuracy, and is web-enabled. One Genus buyer in South Wales, which sells ladies wear, uses it to check all stock despatches and expects a three-month payback, an unprecedented return on investment for such machines.
When choosing a trolley-based system, users should be aware that 10% of the tube or rail length would be lost, says Salpomec, who have hundreds of systems installed in over 30 countries, and if not mixing styles or shipments in a trolley, the savings with their Magic Tube could be easily 30%. One also must reserve extra space for empty trolleys and design return lines for them, even when there is only one-way flow of material.
Automation is often justified by claims for higher productivity but manual systems like Salpomec's Magic Tube have shown remarkable productivity gains. One Portuguese clothing maker reported a 15% production growth compared with its previous system. Another showed throughput times reduced from 1-2 weeks to 1-2 days and improved quality.
Further information:
Keith Turnbull,
Kinesys Technology,
30a Derby Road,
Ashbourne
Derbyshire,
DE6 1BH.
Tel:01335 348119.
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