Ironer management for quality & productivity10 August 2022
Learn to manage your ironer correctly to ensure you turn out consistently good results, says Richard Neale of LTC Worldwide
The quality of the ironed product is frequently used by the customer to define the standard of the launderer. It is obvious as soon as the first package of a delivery is opened and it takes very little for a poorly presented or heavily creased sheet to be held up for all to see, with the cry “Look what they’ve sent today! They can’t even iron it right!”
Modern ironers are capable of giving a superb finish, hour after hour and day after day, but failure to manage them correctly often gives very disappointing results. This month we look at what the launderer can do to achieve near- perfection, at no significant cost. In fact, in the hands of an expert launderer, ironing costs can often be reduced. Let’s see how they do it
Tuning an ironer – what this Means
An ironer will not deliver its design quality or productivity unless it is correctly tuned and kept in tune., An ironer needs daily observation so that symptoms of any emerging fault can be recognised and corrected before they become problems.
This starts with the ironer set up. A steam heated ironer requires steam which is at the correct pressure for the fabrics being ironed. 8-bar steam works well for cotton and for polyester blends, including cotton-rich. Operating above 8-bar is fine for cotton (it irons well up to 200C), but it will risk major distortion problems with polycotton and cotton-rich. This is because above about 70C 170? the polyester fibres start to soften and the fabric loses its strength, allowing progressive distortion of the entire sheeting stock. This can be recognised (too late!) by production of cotton-rich sheets which no longer fit the bed.
The steam must be dry; any water droplets (from boiler carryover, or poor insulation) tend to form an insulating layer on the internal surfaces of the beds, which can be recognised by poor productivity – the ironer simply will not dry the textiles fast enough.
If the ironer uses thermal oil instead of steam, then the thermostat setting on the oil from the heater must be set to the correct maximum temperature for the textiles being finished. If the operatives need to change this between batches (for example, to switch from cotton-rich to 100% cotton), this must be clearly indicated and readily adjustable.
Having got the heating correctly set up, a check should then be made that it is delivering bed temperatures which are uniform to within 2-3C across all of the heated surfaces. Cold spots result in areas of 'rough finished' textiles, with damp creases and crumpling, which are generally unacceptable. Effective steam trapping and associated air venting will often cure a cold bed area on a steam heated ironer. The ironer needs traps which clear condensate at the rate at which is formed, with correct air-venting. Poor circulation is usually the problem with cold spots on an oil-heated ironer.
Moisture is removed as water vapour from the drying sheets, and this is evacuated by vacuum suction through the cladding on the cylindrical rolls. Correct vacuum suction is essential to optimum performance, so it pays to check the rotating seals on the roll ends and all of the joints in the vacuum system for inward leakage. Keeping the vacuum ducting and the back of the vacuum fan blades clear of calender wax will also help to maintain the correct suction, without which the ironer will never perform as required.
The ironer rolls are intended to be perfectly cylindrical, with a diameter which matches perfectly the diameter of the cylindrical beds into which they fit. The correct diameters of the clothed rolls should be specified in the ironer manual. Some ironer designs specify gradually increasing diameters going through the ironer (to achieve the correct inter-roll stretch, to give optimum finish and productivity), so this needs to be addressed in detail. This is absolutely essential for both quality and productivity. Under-clothed rolls do not dry the textiles properly; over-clothed ones can ‘bridge the bed’, lowering productivity and producing ‘nip marks’ at intervals. The objective is to get perfect roll-to- bed contact with uniform contact pressure. The difference between excellent performance and low output is often only a few mm error on roll diameter.
Checking the ‘ironability’ of new deliveries
It becomes quickly apparent that good laundry engineering is key to success in getting the design output from a laundry ironer. However, there is also much to be done by the textile purchase manager and the operatives receiving a new delivery.
Efficient high-volume laundering, whether contract, rental or on-premise, requires textiles which are designed to be washed and finished in modern high-volume laundry machinery, to give a commercially acceptable standard of finish. This calls for textiles woven from threads with the correct strength, with enough threads in each direction to give the required weight and tenacity. It also demands that in the finished items, the warp and weft threads are at right angles to each other and generally parallel to the seams.
Experienced suppliers of large stocks for high-volume laundering are familiar with these requirements and are capable of checking each of their large deliveries for each of the critical parameters which can result in disaster for the launderer. Many small laundries and textile users rely on their established suppliers and do not need to subject every batch to a range of textile tests, and this generally works well. All they need to do is to retain two samples from every delivery for say six months, so that if things should go wrong they have new samples to get tested, to support any claim for compensation. Even experienced supplier can make mistakes or fail to test adequately and when they do this advice will prove invaluable. If the batch proves to be all right, then the retained samples can be put into the circulating stock and the precaution has cost nothing.
There have been major problems with textiles (especially bed linen) which have not been correctly de-sized in the manufacturer’s finishing plant. This is the common cause of new textiles which give cracked-ice creasing for the first 20 washes or so, which the ironer cannot remove. The simplest check for this is to place one droplet of water on the new textile and observe how long it takes to absorb into the material. If it takes less than three seconds, then it has been correctly desized. If it takes much longer then a washing and ironing test is needed to make sure it is acceptable.
Minimising energy use
All of the advice given in this article is relevant to minimisation of energy consumption in ironing. It therefore makes sound sense to maximise its productivity, run it at maximum output and then shut it down if no longer needed. In practice, the most valuable result is to get three inefficient ironers overhauled and tuned and then aim to get through the daily workload with only two ironers heated up and running, saving both energy and labour. The potential improvements possible in a great many laundries should be quite capable of achieving this outcome!
Maximising productivity while maintaining quality
Laundries should be quite capable of doing the tuning and achieving the productivity benefits described here. However, it also requires the focus on initial textile quality in every delivery to achieve productivity whilst maintaining finished quality. This calls for an integrated approach from the purchasing manager, the laundry manager and the ironer supervisor to set up the training and techniques required and to institute daily observation of the ironers and their performance. Getting the benefits described calls for constant vigilance and informed action.
Improvements of the magnitude and significance described here are possible to all by following the steps highlighted above. Whether operating new and recently commissioned ironer lines or those with a few more turns on their rollers, tuning the ironers and presenting them with textiles fit for purpose and of a consistent fibre content and construction will improving results in any laundries energy per kg produced and labour productivity in pieces per operator hour and those who are focussed on these are righty enjoying the success this brings.
- If you have a problem that you think LTC Worldwide can help with, or that you feel would make a good subject for Material Solutions, please call T: 00 44 (0) 816545