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Management of Soiled Linen

Reception

Soiled linen arrives at the launderers' premises in a number of ways and is often a mixture of articles which cannot be processed together for a variety of reasons.

The launderer's first duty therefore is to receive soiled articles, which he will cleanse and finish to an acceptable state, then return them to the sender, or into a pool of rental articles.

The need to return articles to user or stock will affect the method of receipt prior to classification and laundering; for example it may be necessary:

  • to apply a temporary mark to items received from individuals in order to identify them and trace them through the process;
  • to count and check against the laundry list those items which are permanently marked;
  • to produce invoices ready for return, often using an autopricer;
  • to sort into pool stock without counting; or
  • to redirect personalised items often identified with different colour tags to a different classification area.

Items which have to be returned to sender on the same day, or within 24hrs, will also require clear identification on receipt, to ensure urgent attention.

Soiled laundry containers may also be used for returning clean work to the customer and a wide variety of sizes and types are used often in combination. These include:

  • boxes - disposable, plastic, fibre or cardboard
  • wicker hampers
  • roll pallets and skips
  • laundry bags
  • pull cord - with string through eyelets

  • press stud - fixlock buckles

  • pinch clip buckles - zip fastener

  • soluble tie - soluble plastic bags

  • article wrapped and tied (sheet, tablecloth or pillowcase)

There are advantages and disadvantages with all types of containers. The selection of the method of bagging or packaging of finished work will to a very large extent dictate the type and style of containers selected, the type and size of vehicle required and the method of receiving soiled returned work from the user or customer. No single system is correct for all situations or operations and it will be for the launderer to decide which system or combination of systems will be suitable for the operational needs of the laundry and the customer.

However, it is essential that this aspect of the operation be given very careful consideration if the reception, processing and subsequent return to the user of laundered items is to be seen as providing a timely, efficient and quality service.

As this report concerns mostly  hospital laundry, bags are commonly used and these will be discussed in some detail.

Laundry bags

  • Pull cords become tangled in wash.
  • Pull cords may be cutt off by customer.
  • Nylon/terylene/polyester bags may be torn by 'drag'.
  • Water seepage through laundry bags from either wet articles or external storage, resulting in damage, soil transfer or staining.
  • Buckles and studs become damaged.
  • Wrong type of plastic bags may be used and may not dissolve leaving work unprocessed. Unsuitable polythene bags may end up in driers.
  • Strings is usually dropped onto the floor and can become entangled in barrow wheels.

Bags are easily stored in piles or in spare containers and may be coloured and permanently or temporarily labeled to identify sender. Colours aid rapid identification by drivers who may:

  • unload to different customers; or
  • categorise work in predetermined areas or units.

For units processing hospital laundry coloured bags are used but it may be helpful to describe the colour system used in the UK. These are white for general soiled linen, and red for potentially infected, blue for personalised items and green for theatre items.

For easy classification within the laundry, hospitals and other customers should be persuaded to pre-sort or partially pre-sort in the hospital central sluice room. Hotels with chambermaid trolley may be able to use a two bag system on the linen trolley.

Pre-sorting at point of use namely ward level is not acceptable. However, a certain amount of pre-sorting can be implemented by placing soiled linen bags of different colours in different areas, e.g...bathrooms, bed trolleys, kitchens, theatre, uniform, banks, etc. Further co-operation may be gained by persuading nurses to strip beds in two parts, sheeting and pillowcases as one category, blankets and counterpanes as the second. Final sorting would take place in the hospital central linen/sluice room.

Transport arrangements (if the laundry is remote from the user(s))

Vehicle utilisation can be maximised by use of containers which can be unloaded quickly and permitting rapid vehicle turnaround.

Options:

  • Swap body vehicle or trailer, loaded/unloaded by laundry personnel. Driver and vehicle used to a maximum. Increased storage space available at laundry to aid sequencing.
  • Roll pallets/trucks. Eases unloading/loading and promotes fast vehicle turnaround. Requires increased capital expenditure and more internal space in the laundry. However, bulk packing in the laundry direct to pallets could also increase output.
  • Loose stacked laundry bags. Full utilisation of vehicle body space possible but slow turnaround of vehicle. Potential for soiled laundry bags to be dragged or thrown, causing damage to bags or contents.

Internal laundry storage can also affect reception and turnaround. Monorails slow down storage procedures compared to stacked laundry bags. Rail systems may also require increased building capacity.

Storage of soiled linen

Basic requirements - to store incoming soiled linen in the most economical and convenient manner and then to transmit it is a suitable form to the sorting room.

In recent years it has become increasingly popular in large laundries in the UK and elsewhere to adopt a system of storing soiled linen in overhead monorail conveyor systems. The theory underlying these systems is that containers are unloaded from collecting vehicles directly onto the system; that soiled linen is delivered to sorting and classifying stations as required. The conveyor systems may be fully powered; fully gravity assisted; or a combination of both, depending on the operational or building constraints.

The operation of the system required fully integrated distribution system of transport and containers to operate effectively. Difficulties will occur where these aspects have not been fully considered.

It has been noted that in almost all situations where overhead monorail storage is used, an essential item of equipment is a long pole! This indicates one of the numerous problems that can arise using the monorail system for storage.

An alternative to the monorail storage is to stack the incoming soiled linen containers on the floor of the reception area. This is the most common approach in large South African laundries. This system presents several attractions:

  • The cost of the conveyor system is avoided. This includes the support system which, if suspended from the roof, necessitates considerable strengthening of the fabric of the building.
  • Roof heights can be considerably reduced which also can be reflected in lower building costs.
  • Although standard containers are desirable they are not essential since the system does not dictate their use.
  • If it is necessary to segregate certain containers for priority processing, these can be separately stacked and are thus immediately available as and when required.
  • Area for area, much more soiled linen can be stored. As an example: 11 tonnes of soiled linen can be stored in four stacks to a height of 1,5m on a floor area 15m x 8m allowing 1,8m circulation space around the stacks. An equivalent mass stored on a single tier monorail system would require a conveyor of about 15m x 19,5m.

If a floor storage system is adopted, means must be devised for drawing of soiled linen for classifying. This may conveniently be done by providing a wide flat belt conveyor linking the reception/storage area with the sorting area and discharging it's load directly onto a sorting conveyor. Such a link conveyor needs to be at a low level so that the contents of the soiled linen bags may easily be emptied onto it and it should be of sufficient length to provide a buffer stock of soiled linen in order that the work of the sorting operators shall not be interrupted.

The advantages of such a system are that:

  • Soiled linen received in any form other than standard containers can be handed forward with equal facility.
  • The engineering maintenance commitment with flat belt conveyors is usually considerably less than with more sophisticated overhead monorails with their complications of carrier wheels, points, switches, solenoids, etc.
  • Floor stacking is a speedier operation than monorail conveyor loading and hence vehicle turnaround times are reduced, leading to improved vehicle utilisation.

Sorting, Classifying and subsequent storage

Basic requirements - To sort the incoming soiled linen, received as a random mix, into classifications appropriate to subsequent washing and finishing processes and to store the classified linen in sufficient quantities to allow the washrooms to function without interruption.

There are many ways in which soiled linen may arrive at the sorting room. There are some instances where containers are simply emptied onto tables or floors. For large laundries consideration should be given to the situation where a stream of soiled linen flows along a band conveyor or where it is deposited in discrete piles on individual sorting tables. Sorting and classification has, at present, to be manual operation where the skills of the operator are employed to identify fabrics and types of articles and segregate them according to process needs.

The containers into which linen is classified may be either fixed or mobile and the latter are to be preferred since the linen must ultimately be transported in some way to washing machines and a mobile container will obliviate one additional handling operation. The broad options for mobile storage are wheeled trolleys of appropriate design or a conveyor system.

Trolleys have the advantage of being totally flexible in their use; as few or as many as are required being used for a specific classification in the particular batch of work being handled. Being free moving, they can be moved to storage positions as required.

Conveyor systems for classified work (as distinct from special conveyors serving specific washing machines, for example continuous washing units) are frequently of monorail type having bags designed for storage of loads awaiting washing, and depending upon the siting and type of washing machines to be served, may discharge loads directly into washing machines or into associated loading hoppers.

Although such conveyor systems can effect some savings in manual effort particularly in favourable washing machine loading situations, they can be restrictive.

The handling of bulk work constitutes by far the largest proportion of a laundry's total input. Items such as staff and patients personal work involves additional requirements but, in general, this small portion of the load can be fitted in alongside the larger systems with little trouble.

Classification of work

Classification of work for processing is an area of critical importance to the efficient operation of the laundry washing and finishing process and to the level of quality achieved in the finishing process and to the level of quality achieved in the finished work returned to the user. The need to classify work correctly  becomes very apparent when the various factors affecting the handling of textiles requiring laundering are examined. These factors should be used both to develop an effective sorting and classification system and to assist in the development of effective wash processes. As it will be recognised that not all textiles react the same way to a wash process and that not all textiles are received in the same state of average dirtiness, it is necessary to start with the largest common denominator which is the fabric type.

Different fibre types should be processed separately and subdivided as follows:

White work

White work should be classified as follows:

  • Light soiling e.g hotel sheets, towels, bath mats
  • Medium soiling e.g. table line, hospital top sheets, rental pillow cases, flakes cabinet towels, vests, pants.
  • Heavy soiling e.g. work wear, hospital bottom sheets, tea towels, contract towels, flaked cabinet towels.

In  many cases it is desirable that classification by soil type is also employed, the three main groups being:

  1. General
  2. Oily/Greasy
  3. Protein

It may be necessary to include other soil types depending on known work loads and end user activity.

These methods of classification aid the correct selection of the wash process to be used.

Allied to this will be the need to monitor and control rewash levels. This will be a further aid and allow the wash processes to be used or adjusted to suit varying needs.

Coloured work

Coloured work should be classified by colour and separately from white work but categorised as in the previous section, making allowance for the fact that soiling on coloured work is often not as noticeable as on white work.

Woollens

Woollens should be classified into garments and flat work and according to colour. Not all wool is suitable for machine washing especially in pocketed, or large diameter, fast running machines. "Hand washing" may be necessary.

Work wear garments

Work wear garments should be classified according to colour, fibre content and type and degree of soiling as indicated previously. It will be necessary to classify also  by end user or customer. This is particularly so with recent changes in requirements for food industry clothing where strict segregation, specific processes, finishing and packaging have been dictated by the customer.

Foul or infected work

Ideally, arrangements should be made for foul or infected work to be delivered in sealed bags which should be of a type which will dissolve during washing or in plastic bags with a soluble panel or stitching.

Modacrylics

Modacrylic items should be classified separately, and washed correctly.

Flame retardant Fabrics

These should be classified separately in order to avoid the use of:

  • hyper chlorite bleach
  • soap or soap-based detergent
  • sodium metasilicate
  • starch or any finish which imparts a dressing to the surface of the fibre.

NOTE: Provided water of zero hardness can be guaranteed then sodium metasilicate may be used.

100% Polyester

Polyester fabrics should be classified separately due to their low moisture retention properties.

Glass fibre

For machine washing, glass fibre articles should be segregated and never washed  with other work.

Contaminated work

  1. Asbestos residues

Strict legislation relating to the handling of asbestos contaminated work now applies in the UK.

     b. Chemical soiling

Chemical soiling may present a potential hazard to either the laundry operator or to the environment. Classification commences with a specialist assessment prior to acceptance of such work

Finishing process requirements

In addition to the above, classification of work should also be carried out to ensure that garments or articles requiring different drying and finishing processes are not washed together which will otherwise require a separate post-wash sorting to be carried out. For example 100% white cotton sheets and towels can probably be washed at the same time but require different finishing i.e. calendering or tumble drying.

Summary

Although there is no "correct" number of classifications, as this will depend on the nature and size of the laundry operations, it is considered that the largest number of classifications possible should be used to allow the most efficient and cost effective processes to be applied in both washing and finishing areas.

It is of course accepted that against this ideal, are a number of factors which may dictate some compression of an individual laundry's ideal number and these will include:

  • the availability of items to make up economic loads
  • the customers requirements for quick turnaround of work
  • the need to maintain a balance between washing and finishing sections/departments
  • the size and nature of the operation.

However it is an observation made by FCRA on many occasions, when investigating problems for launderers that a large number of these are traced back to poor, inaccurate and often total lack of a classification system within the laundry operation.

Good classification of work can greatly assist and improve the cost efficiency and quality levels of a laundry operation.

Marking systems

Within the laundry industry a variety of marketing systems are used, primarily for one purpose, which is, to identify the ownership of an article being laundered.

Reasons for marking are numerous. For hospitals includes

  • to identify ownership
  • to aid security of the article and assist in loss prevention
  • to ensure the laundered returns the correct article to the user
  • to aid sorting, washing and finishing

Marking will take two basic forms

  1. temporary marking
  2. permanent marking

1. Temporary marking

Temporary marking is normally applied by the launderer upon receipt of an article from a customer to ensure that after laundering it returns to that customer. The mark is temporary because the launderer cannot apply permanent labels to articles without prior consent of the customer. A well known method known as the "Polymark" system, where coloured, numbered, label is applied with an adhesive which will withstand laundering without affecting the fabric. The weave of the label 'sufficiently loose' to permit soil release from the fabric below the label and the  adhesive is only applied to approximately 75% of the label area, leaving a loose flap to facilitate easy removal of the label when required.

A variety of label colours is readily available with a sequencing of numbers to uniquely identify each customer's work through the process. Alphanumeric codes are also used.

2. Permanent marking

Permanent marking can assume a variety of forms:

  • pre-printed launderers fabric heat seal adhesive labels
  • pre-printed launderers paper heat seal adhesive labels
  • computer printed heat seal tape
  • dye set prints direct to fabric
  • woven badges for 'sew-on' application
  • embroidered marks - monogram; hand/machine customised
  • indelible pens
  • transfer marks
  • bar code labels
  • radio frequency tags

The advent of SUPER TAG will hopefully provide solutions to many of the problems associated with marking systems listed above. This miniscule radio transponder would be integrated into a visual marking system chosen by the user. Visual marking systems should always be used for manual sorting and identification. The choice of system used will depend upon the fabric and the user organisations' needs and preferences.


This information courtesy of Division of Building Technology, CSIR.

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