Automation in a textile rental plant can become an obsession. It is often seen as modernisation and a virtue to be pursued relentlessly.
However, many plant managements are finding that ambitious plans to automate, when subjected to close scrutiny, often need reigning in.
Automation in the UK textile rental sector has grown steadily in the last two decades, driven by a need to reduce plant costs in a fiercely competitive and price sensitive marketplace and a requirement to handle work in bulk more efficiently.
Soiled flatwork and garment sorting is likely to remain heavily dependent on manual tasks. However, it can now be justifiable to put an identifying “chip” in each rental garment so each item is automatically checked in and directed to the right position for processing.
Unfortunately though, technology has not been developed to check workwear pockets and turn down sleeves. Electronic tags are still too expensive for use in flatwork, and the ability of chips to withstand the rigours of ironing is still to be addressed.
Martin Bull of Ducker UK says the arrival of the flatwork chip may still be a few years away. It may come as a spin-off from the development of chips for use by supermarkets where a whole trolley of items can be “read” instantaneously.
Counting systems have their merits, but their efficiency, in any given context, needs careful evaluation. Light frame counting uses expensive technology, and accuracy is dependent on the ability and concentration of the sorting staff. Using extremely accurate electronic load weighing to determine numbers of items being processed is now established as a totally efficient method.The use of the correct amount of labour in the sorting department should be clearly identifiable as cost effective. There is no doubt that robotic sorting assistance could be developed, but at a huge and unjustifiable cost. Advances in computerisation and mechanical handling technology mean that just about any stage in laundry production could theoretically be automated. The crunch comes when the capital cost of automated units, and cost-effectiveness, are considered. Automating up to a certain point is relatively straightforward and makes a lot of sense. Going beyond that tends to be prohibitively expensive.
Manual readings
Clément Silvaggio of Polymark Jensen, France, points out that the need for full traceability of workwear items has led to launderers reading bar codes up to three times: on the soiled side, at the inspection station, and in the despatch preparation area. All these readings are done manually on each garment, and productivity is lowered.
The new trend, he says, is to have only one reading, either at the inspection station or at the hanger-loading station. Disappearance of an item in the production plant is extremely rare. This trend means that there is a requirement to have a larger storage capacity for clean garments prior to sorting because exact quantities to be handled are not known. The maximum quantity that may need to be dealt with has to be considered.
In the near future, Mr Silvaggio predicts, batches containing 50 tagged pieces will be able to be read and this will help with the organisation of storage of clean garments prior to sorting – exact quantities expected will be known.
Thinking has changed on the storage of flatwork cakes between the extraction press and dryers. Storage of three or four cakes ahead of each dryer is seen as good practice as it enables dryer production to be optimised and should prevent dryers being idle as a result of poor work sequencing through the continuous batch washer.
In the past, Mr Silvaggio says, some laundries made the mistake of creating extensive cake storage on a long conveying band, this is less expensive than the provision of several shorter conveyors. A long conveying band allows a “first in, last out” approach to be used, with the possibility that some cakes remain in storage for hours. As as result, the moisture retention level in terry towels could drop too low, and creasing be set in table linen.
The use of a dryer for breaking cakes is beginning to be increasingly seen as undesirable. Action of the dryer drum tends to tangle flatwork. When 50/50 polyester/cotton sheets form the classification, it has been found that if the cake is stored on elevated conveyor bands and simply allowed to drop once or twice, the breaking effect is better than that achieved with a dryer. The best productivity on the feeders will then be obtained by installing an automatic flatwork separating unit.
Mr Bull says sheet pickers, for untangling flatwork in preparation for feeding to ironers, are becoming popular in the UK textile rental market. For a relatively modest outlay, the pickers give a significant boost to productivity.
For many years, overhead rail conveying of work has been a boom for rental plants. Recently, more thought has been given to automatic distribution of work, entailing computer-organised storing of batches. In Continental Europe there has been investment in systems that allow a different storage line to be used for each classification being handled. The way in which the work is automatically called off from the storage lines means the capacity of the finishing equipment can be continuously filled.
Such investment has been possible because of the price per piece achieved. However, the UKs depressed prices mean that this level of investment is unlikely to be widely seen at present.
Great care needs to be taken with planning automation in the finishing department. Conveying, buffer storage, feed, fold and stack techniques, stack handling, and pre-despatch storage all need to be considered individually and together. This is not just so that optimum efficiency, and the desired quality standards can be achieved with the immediately envisaged workload but also so that increases in work volumes can be accommodated without flow bottlenecks or other problems.
Mr Silvaggio notes that fully automatic storage systems for work awaiting despatch are not very commonly used because of their high price. However, it can make sense to use such a system in plants handling healthcare classifications.
For healthcare, pharmaceutical sector and food industry work, the launderer is increasingly likely to have an obligation to provide full traceability of any work batch.
Software for computer systems providing this traceability needs to be most carefully developed and applied as data from different types of machines is handled. Effecting the right level of communication between different items of equipment can be technically difficult, and may be expensive, when different brands are involved.