Lint is always the natural fall-out whenever textiles are processed, irrespective of whether you are dealing with a mass of staple fibre or made-up articles for use. It will accumulate everywhere: on top of steam or condensate pipe runs, flat surfaces such as tumbler tops and plant machinery. The rate of formation to an extent depends upon the types of textiles being processed, but if it is allowed to become excessive it is hazardous to health and a fire risk.
In some plants—such as those processing wipes, engineers heavy cotton overalls and other workwear, dust control mats and mops—the eternal accumulations of lint are not always treated as seriously as they should be.
In hospital laundries and rental plants specialising in hospital linen care services and the provision of sterile, bacteria and lint free surgical packs, on the other hand, the suppression of lint accumulations as a deposit is taken very seriously indeed. This is equally the case in plants where cleanliness and hygiene are a pre-requisite of the service process and production planning.
The removal of accumulations as fall-out from airbourne polluting lint ought to be handled by an on-going planned good housekeeping regime. All surfaces where lint can be deposited should be vacuumed on a daily basis. This process would usually be undertaken after the plant has closed-down at night but, depending on the types of linen and other articles being processed, vacuuming may be necessary twice or more times per day. The regime should also include the cleaning of all work positions so that lint contamination is kept at an absolute minimum.
In many EU counties, reducing lint contamination is taken as seriously as the elimination of bacteria or viruses, to prevent the cross infection of patients.
The responsibility for ensuring that laundered, conditioned and fully dried items are as lint free as is technically possible falls upon the machinery manufacturers themselves. To achieve this, not only are continuous batch washers designed to include automatic sterilisation procedures which have to be completed before the machine can be re-started after an overnight close down, but these procedures would also be implemented if the machines are stopped for periods in excess of a set duration (usually thirty minutes). This is mandatory by health authorities in many countries.
There is increasing use of recovered process water for the main wash and the first and second rinse stages, and it is important that this water is not contaminated by lint debris. To this end, machines are fitted with effective lint screens which need to be cleaned regularly to a planned maintenance schedule.
However, it is during tumbling–either conditioning or full drying–that most of the fibre particles which have worked free during wear or processing are dislodged. To ensure that the circulated air is as free of this liberated lint as possible, double or triple tier lint screens are often used. These vary from a primary, relatively coarse screen down to a fine filter which can remove the cotton fibre even if it has been reduced to dust.
These screens have to be thoroughly cleaned and brushed at frequent intervals. Failure to do so will result in a reduction in the rate of air flow, longer drying or conditioning times. All of these will add to production costs and, what is worse, more loose fibre dislodgement.
In addition, laundries and plants processing surgical wear usually undertake a close inspection of surgical greens, gowns and covers as they are being finished or prepared for finishing. State of the art technology has reached the point, however, when the items can be photoelectrically inspected as they traverse the ironer feed bands as well as during the fold and cross fold stages. Items carrying excessive lint are rejected for reprocessing.
Where patient care is a primary feature of the service, it is the responsibility of management and supervisors to see that these conditions are fulfilled. Good housekeeping is essential. Lint and dust should be removed at least once per day and even more frequently if conditions require it.
It is important to indicate to machinery manufacturers that all recovered and reusable process water should be treated to reduce lint contamination to an absolute minimum.
All the manufacturers I know will supply continuous batch washers with all the necessary lint screens and process water filters in place. It is the management’s responsibility to make sure that the tunnel washers are properly maintained.
This also applies to tumblers. Regular attention reduces health hazards as well as costs. It will also ensure that fires caused by spontaneous combustion do not occur.
In a number of plants I have visited in Germany and in Scandinavia, the hospital laundries are air conditioned so that incoming fresh air and that which is circulated by the system is as clean and free of dust and lint pollution as is possible.
There is a sting in the tail. Environmental protection agencies do look upon the exhausts from batteries of tumblers as a source of airbourne pollution. If the concentrations of fine and almost invisible fibres in this exhaust are shown by tests to be excessive, they can be deemed to be harmful to the health of people living nearby and could cause bronchial or other respiratory infections.
Lint is the enemy within. Left uncontrolled for lengthy periods it can become costly. The plant gutted by fire is the worst scenario. Being closed down by environment protection agencies is almost as bad; and poor working conditions and dirty surroundings will reduce operator output and increase production costs.
A good industrial vacuum cleaner is the first line of defence. The right machinery, designed and modified for lint-free processing, is a second line. But a good housekeeping plan, devised by management and strictly adhered to by the staff, is the most important.
