Smooth path to ironer systems

I must be one of the few still around in the textile care industry who has witnessed the transformation of the ironer from a mechanical steam heated machine requiring a multitude of women operators, anything up to ten or even twelve in number, to a finishing system needing no more than two or three people, at the machine or remotely at feeding preparation stations.

The transformation has not been as dramatic in effect as that of the washing machine which has been entirely redesigned, albeit using the same wash principles as those used by the old manually side- or end-loading, individual belt-driven machines.

Nonetheless, ironer developments over the years have been effective. And while the use of advanced technology and feeding, folding, counting and stacking innovations have led us into the realms of ironer systemisation, the principles, like those of washing systems, have remained the same. The ironer is and always has been a machine through which damp items of linen, large or small, are fed between a padded rotating roll and a static heated bed to remove moisture and to impart a dry, crisp, polished finish of good appearance.

These are the same principles that were used on the first ironing machine produced in Belgium around the middle of the 18th Century. Alternatives to the horizontal linear configuration have been sought for but none have been found which were successful.

The starting point for a brief historical survey has to be the Decoudin, a single roll machine with a diameter of a metre or more and a deep, steam heated bed. Well-polished damask table linen and napkins of quality appearance, good colour and crispness were demanded by the managements of top class, palace hotels and the housekeepers in the employ of the opulent middle and upper classes. And the Decoudin was used in a lot of French laundries for finishing this linen classification to a very high standard.

I remember that James Armstrong & Co Ltd were, I think, the only British manufacturer to produce a similar machine to the Decoudin. It was called the Amazon ironer.

Cast iron beds were favoured, and none was better than that produced by the Dutch manufacturer Rheinveld, who used a special alloy for its beds to give a fast and effective heat transfer through the steam heated bed to the linen being processed. The Rheinveld ironer was renowned for the high standard of finish it achieved but it was an expensive machine. Owning a Rheinveld ironer was the equivalent of using a Rolls-Royce motor car.

As the demands for production rather than pristine appearance grew, the Rheinveld was elbowed aside by machines with steel beds.

Steel beds were cheaper to manufacture and had good heat transfer characteristics, provided that the annular steam channels inside the bed were properly formulated and well-ventilated to get rid of occluded air and other gases, and that the steam taps efficiently got rid of condensate. There are now no ironers made with cast iron beds.

Further evolution of the ironer has seen the arrival and departure of solid surface cold rolls, ventilated rolls with suction to remove moisture evaporated from the linen, and vertical ironers. The latter had two or three rolls stacked one on top of the other vertically instead of being arranged side-by-side horizontally in the conventional way. All these machines flowered briefly because they were space saving and beneficial to small laundries where room was at a premium. As ironers they were not very effective.

There are three ways of heating an ironer: steam, thermal fluid and high pressure hot water. With steam, the bed temperature will depend on the steam’s pressure and quality: the latter, high pressure hot water, seems to be popular in Australia but few places elsewhere.

Thermal fluid heating was pioneered by the now demised BLRA at Hendon, where it had the first wholly thermal fluid heating laundry in operation.

I was an advocate, and still am, of thermal fluid heating. It was hotter than steam at the highest pressure which could be used, and without risk of pressure accidents because there is no pressure with thermal fluid. It is 25 to 30% cheaper in energy costs, as a two roll machine will produce as much work as a three roll steam heated model of the same roll size.

Almost all ironer manufacturers have produced thermal fluid heated machines at some time or another. However, they all thought that the same annular channels could be used for either steam or thermal fluid, and often with little or no variation in configuration. This was not the case. Thermal fluid passing through annular channels designed for steam often caused the outer layer adjacent to the underside of the bed to cool. The hot thermal oil would then flow through the centre, in effect making a bore hole, and the cooled layer would become as effective an insulator as occluded air and gases. At this point, thermal fluid heated machines actually produced less work than an equivalent steam heated one.

Literature from the time, I remember, pointed to the fact that these ironers could be used for either media effectively. This was not proven by production or finished appearance results.

Yet with the correct annular channels, thermal fluid heating will do all that is claimed for it. D’Hooge, with its long experience of thermal fluid heating, will not be caught in the trap and nor will Lapauw, another Belgian company who introduced a thermal fluid heated ironer at the recent Clean ‘99 show in Orlando. Both of these companies appear to have got their acts right. I’d need to do a closer study to confirm this, however.

Thermal heating is more environmentally friendly, an advantage these days, but a word of warning: linen coming off the machine can be at a higher temperature than that from a steam heated one. Even after folding, protective gloves are a must to prevent burned fingers.

The transformation of the ironer, over the years, has been slow and almost unobtrusive. It has gone through a whole series of variations. We have had solid split, flexible, full wrap, half wrap beds, wide gap pieces and narrow ones as well as various roll diameters (from as low as 200mm up to a metre or a metre and a half). We have had spring and laminated paddings in the place of permanent springs locked into perforations in the roll surface. Very little was done, however, to contain the radiated heat. Beds were not insulated. Radiated heat was given off along with moisture when linen was being ironed and was permitted to escape into the local atmosphere. The result — on hot summer days the temperature around the ironer could exceed 35°C. It was a working environment which would not be tolerated today.

Now we have insulated beds, canopies to contain above the bed heat and moisture, efficient exhaust systems to keep clothing relatively dry and, above all, improvements in the working environment.

Modern ironers are constructed with dynamic stainless steel beds of a laser-welded sandwich form to accommodate roll diameters up to 1200mm. Narrow annular channels assure good scouring of condensate and occluded gases, operating pressure is 13 bar and the beds have a bursting point of 123 bar. There are direct steam heated gap pieces.

Production is not materially reduced when the roll clothing wears and becomes compacted as the bed has the ability to flex to meet the changed contours. The beds thermal efficiency is improved as it is thinner than conventional beds. There is also improved contact between bed and roll over the whole ironing surface.

It is claimed that a two roll ironer with steel band beds will produce the equivalent of a conventional three roll model. Efficient heat transfer cuts steam costs, needs less space, gives good drying and finishing quality and has less need for repeated and frequent bed waxing treatments and tapes. It is also said to break down far less frequently due to lowered friction between bed and roll.

Modern technology allied to computer control has brought a new dimension to ironer performance and versatility. Re-designed drive systems have cut power consumption.

Improved roll suction techniques mean longer clothing life and ‘wet’ clothing no longer impedes air flow. Add to these benefits infinitely variable speed drive motors, AC with DC converters, an almost frictionless drive to the rolls cutting power costs and running speeds (which can be varied to meet the needs of different classifications of linen automatically through computer control), and it is easy to see how much ironers have improved.

An ironer can, however, no longer be judged as an individual item of capital equipment as it once was. The ironer is now an integral part of a total ironing system, highly productive and capable of sustaining a consistent quality of finish which itself can be programmed.

How far the improvements in ironer design have taken us can be appreciated by the fact that 30 years ago a three roll ironer with 700mm rolls would yield not more than 50 pieces per operator hour.

Today, two operators are all that is needed to produce 500 pieces per hour each.

That is what systemisation coupled to design improvement means.