Sorting and classifying

Establish an efficient sorting operation

4 January 2010



The modern laundry’s commitment to quality includes complete sorting of linen and garments into their correct classifications. Tony Vince examines what this process involves


With increasing volumes of work required to operate efficiently in today’s highly competitive textile rental market, the modern laundry must ensure its sorting department is using its staff efficiently.

Processing hundreds of thousands of items of dirty linen each week means that the laundry will gain an understanding of its customers’ requirements and the types of soiled linen they usually send in.

A quality assurance plan ensures that systems and procedures are in place to guarantee that services are provided according to the standards set. This commitment to quality will include complete sorting and separation of all textiles into their correct classifications. In most cases this will be done before washing but foul and infected linen should already be separated out and bagged up in special bags and must be sorted after washing. The classifying process means that specific formulations can be used for each specific textile type used.

The final result on any item sent for laundering is dependent on the very first part of the process – sorting, according to Peter Beer of the Satra Technology Centre.

He says: “The sorter should have a list of checks to carry out before adding the item to the load and the decisions made will dictate how good the soil removal and finish will be.” Classification should also take into any risks of damage to the items.

He suggests a typical check list for the sorter should include the following:

• Avoid mixing different classifications. For example, mop heads should never be washed with clothing; kitchen wear should only be washed with other kitchen wear and not with bedding.

• Check the care label. Failure to process the item as recommended by the manufacturer may result in the launderer being held responsible for any damage.

• Determine fibre content. A load type with similar fibres will help to avoid pilling, thermal shock and shrinkage and reduce problems in the finishing department.

• The degree of staining and soiling must be considered when choosing load types as temperature, mechanical action, time and additives used will dictate final cleanliness. Choosing the wrong load types can produce greying on white items due to redeposition of the original soiling.

• Watch for oily soils and fats. If items with this type of soiling are not washed correctly so all staining is removed, the residual oily soiling can present a fire hazard in the drying process.

• Wear and tear. An aggressive wash can cause wear and tear on the more delicate fibres which, in turn, will affect the life span of the item.

• Chemicals and additives dosed into the wash are pre-determined and may have a detrimental effect on certain fibres. Chemicals may remove some finishes such as fire retardants and waterproofing, so the sorter must ensure such items are washed correctly.

• Washing similar colours together reduces the risk of dye transfer to paler or different coloured items.

• The sorter should check for imperfections, damage or other faults and flaws before laundering. If not, the laundry can be blamed.

Peter Beer says that in most cases the sorter is responsible for weighing the loads after making the necessary checks. “If this is not to the manufacturer’s recommended weight, it can cause damage to the work and the washer.”

Mersey Towel Service (Laundry) is an independent laundry that has provided high quality laundry and textile rental services to the commercial and industrial sectors for over 70years.

It operates a dedicated stock system for most of its rental clients and also has a pooled stock that is used for one-off hire. MTS is a traditional laundry where sorting is all done by hand, says managing director Giles Hooker. Several MTS staff have successfully completed the NVQ Level 2 course in Laundry Operations and sorting is covered in one of the course modules.

Hooker says that most of the sorting procedures described in the training are already in place at MTS, but the module explains the background and reasons why these procedures are needed.

“The most important lesson our staff will have learnt is how their actions at the sorting stage have a direct influence on the operating costs of our laundry,” says Hooker. He adds that the goal of getting it right first time every time makes running of the laundry so much easier and therefore improves its profitability.

Soiled linen is checked for obvious damage (for example, defacing by pens or candle wax) and any other problems that mean the item needs pre-treatment or has to be replaced.

Once checked, the items can be sorted into their different classifications and loaded into cages or trucks, before sequencing, weighing and washing. Larger customers will have their items washed in separate batches, which makes it easier to sort after the finishing processes.

Possibly the most important check during the sorting process, according to Hooker at MTS, is that all items have a legible label which is securely attached.

MTS uses heat-sealed labels and have recently moved to the Mediron2 system from Thermopatch. This will stop the labels fading which should speed up the sorting process and reduce the amount of re-labelling.

Labelling is especially important with regard to batches that contain items from different customers.

After checking, the next crucial stage is to record the items accurately. This prevents the frustration and time lost in the finishing/packing area later in the process, an important concern when fast turnarounds are required.

Question of automation

The level of technology selected for the sorting process will depend upon the size of the laundry, the type of garments they are finishing and the standard required. Smaller laundries may have a broader mix of garments that can be processed in a single machine and for them a manually-operated system is likely to be most suitable.

Although the technological developments in this laundry sector may not seem to have moved on as dramatically as in other areas, it is clear that it is advancing into areas that can improve both efficiency and quality.

Where industrial launderers find themselves under pressure to improve throughput whilst controlling costs, modern automated garment dispenser systems allow laundries to be quicker and more accurate at a fraction of the labour costs of a manual sorting system.

State-of-the-art production technologies also provide a safer work environment and improve productivity without compromising high quality standards. Automated sorting systems can now be scaled to any size operation and help to minimise operating problems such as employee fatigue and the risk of repetitive stress injuries.

With the developments in barcodes and radio frequency identification (RFID), linen and garments can be automatically detected and processed. However the use of RFID technology for flatwork is still an area where the results are inconsistent. Here the cost of applying the technology to flatwork production can be high while the process of scanning can cause throughput to slow.

A typical garment handling system can extend from simple manual conveyors to an extensive range of fully automated conveyor systems that assemble, sort, dispense, organise and manage garment processing operations. Because of recent advances in modular automatic sorting technologies, any laundry currently using space for a manual garment sorting process is a viable candidate for conversion to automated sorting.

At Vottem in Belgium, the Jensen Group has just completed a turnkey installation for Ardennes & Meuse Laundry (A&M Blanchisserie Basse Meuse), the family-owned specialist in textile rental for the region’s hotels and restaurants. The increased automation of A&M’s laundry process is very important, says general manager Marc Broers.

He explains that soiled hotel laundry is sorted into 50kg batches before washing, according to customer and category, using Jensen’s Futurail Tri-Sort system.

A Jensen Futurail bag conveyer system transports the clean laundry to the finishing area as required.

This sorting system for table linen determines the exact number of soiled items delivered, such as napkins and tablecloths. The soiled items count is automatically captured and is compared with the delivery contracts for customers.

The laundry operating system sends the delivery priority to the Jensen’s central production monitoring system, which decides the order in which lots must be washed. This monitoring system knows before the washroom starts work the type and number of laundry items that must be delivered on the same day.

Finally, the central monitoring system supplies the local laundry operating system with exact data to create delivery notes and invoices for end customers.

Marc Broers says it is possible to punctually deliver clean napkins in the afternoon to customer A that come from a load of soiled napkins sent by customer B the same morning, without having to hold large stock levels. “This makes our job considerably easier and helps us to react quickly to customer requirements,” he adds.

Faster garment handling

Textile rental companies process a wide range of different types of garments and uniforms, ranging from gowns to trousers and T-shirts, and automation allows them to handle high volume in a shorter time and with fewer staff, according to Jensen’s marketing director Kathrin Scheffel.

At the same time, textile rental customers require excellent finish, accurate sorting, various folding templates and particular dispatch methods.

The Jensen Group’s most recent complete solution systems for garment handling and sorting can be be found at the Alsco plant in Padova, Italy. Alsco is a global industry leader in the textile services sector. Its Padova plant processes approximately 11,000 garments in 10 hours each day. It uses Jensen’s Metricon sorting system which sorts all garments using “Route and Sort” criteria – by size, account, customer, locker bank and wearer.

All garments are transported on automatic system hangers (called Lobsters), as 95% of the garments are automatically folded, wrapped and labelled before leaving the plant. Only 5% of all garments are delivered hanging on a wire hanger.

The garments are equipped with an RFID chip so that information on sorting specifications and location for exiting the system can be received from the garment RFID reading at the loading/cross-feeder/re-introduction stations. These are all connected by means of the Metricon Control PC (MCPC) and logged on the garment database at the Metricon File Server (MFS).

All supervisors use the Metricon Live system on hand-held devices so they can answer queries from anywhere in the plant. The MFS computer at the central desk displays the entire garment finishing system, including alarms and real-time production statistics.

Jensen’s recirculation system, which has a sorting capacity of up to 2,000 garments an hour, is capable

of processing individual garments and garments sorted by article and size only.

Before sorting, the garments are allocated into the pre-sort (A-sort), which looks for garments following the same route, then for an empty rail, or the rail with the fewest garments.

The A-sort has a storage capacity of up to 10,000 garments and as many as 40 Lobster hangers can be stored per metre on the Metristore. When A-Sort reaches its full capacity, feeding is automatically stopped until sufficient space is made to allow re-circulating garments to re-enter A-Sort.

The recirculation A-sort system has a special buffer (capacity of 1,000 garments) between the pre-sort and final-sort to increase the sorting capacity. As soon as one route enters the final sorting stage, the next route that was parked in the special buffer can enter the final sorting stage. This saves time in discharging a route by splitting the garments over 2-3 rails in the pre-sort stage and then transporting them to final sorting. Each Jensen Metrifeed garment loading station is equipped with an RFID reader and flat antenna to identify garments and an RFID antenna to read the RFID hanger chip.

At each loading station, the operators check the data matching or “marrying” process on a touchscreen where different destinations are addressed manually.

A manual code can be entered if there are garments without a chip to be processed. All identified garments are allocated to one of two Jensen Omega Plus finishers, according to the finishing criteria in the customer database.

Garments with special finishing requirements are transported directly to the press area by means of a bag system.

Once the garments have been pressed, the operator puts the hanger on the pick-up conveyor, which automatically transports the hanger to the automatic loading station cross-feeder.

Finished garments go past four inspection stations, each of which can be operated automatically and manually. Visual inspection can be carried out and the touchscreen control also allows re-addressing options such as repair, rewash, no read, exchange, stock and A-Sort.

After repair, the operator hangs the repaired garment on the Metristore conveyor, which then transports the garment to the matching station cross-feeder for automatic re-introduction into the system. This means that garments do not need to be placed back on the same hanger. Garments arriving from stock are re-introduced at the same cross-feeder.




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