Linen life - beating the elusive 200-cycle target

A rental textile item which costs, say, US$2.50 and which last for 50 wash-and-use cycles will contribute $2.50 ÷ 50 = 5 cents to the cost of every rental for that classification. If the life could be extended to 200 wash-anduse cycles, then the cost per rental reduces from 5 cents to 1.25 cents per rental. This might not look much, but it is equivalent to saving three-quarters of the annual bill for replacement textiles. In practice, most efficient rental operators probably achieve 70 to 120 cycles depending on the classification, but if they could average 200 cycles this would halve their textile expenditure and it is now readily achievable.

History of linen life

When textile rental was in its infancy, most rental operators used 100% cotton and relied on sodium hypochlorite (chlorine bleach) for achieving complete stain removal. If stubborn stains remained, they either tolerated rewash in excess of 1.5% or increased the dosage of hypochlorite. Higher rewash increased the average wash cost, but this was rarely recognised or dealt with; it simply reduced the net profit. Increasing the bleach dosage usually led to more holes and tears and higher costs for textile replacements and reduced the profit by a bit more. As competition increased, margins became very squeezed and many operators were more than a little puzzled as to how some producers could make a profit at the prices they were charging. In many cases the answer lay simply in shrewd cost management, strongly coupled with modern laundry technology.

Operators in continental Europe were among the first to cease reliance on sodium hypochlorite for stain removal, perhaps because they were forced by national legislation to play their part in halting progressive eutrophication of long, slow-flowing European rivers such as the Rhine and the Meuse. They switched to hydrogen peroxide (or to generators of this, such as sodium percarbonate). This was just as effective as hypochlorite at decolouring vegetable dye stains from tea, beetroot juice and red wine, but was far less effective at removing set protein stains from cream, gravy and other foodstuffs. They rediscovered the importance of getting the pre-wash conditions right for softening proteins effectively (4 minutes minimum, below 40C), so that they all came away in the main wash. Hydrogen peroxide is more expensive than hypochlorite, so there was less temptation to overdose (and overdosing was ineffective anyway). Protein stains have to be removed by good washing.

The transition from 100% cotton to cotton rich was probably driven initially by the substantial energy economies it delivered, coupled with the fact that it looked and handled much more like cotton than 50:50 polycotton (which looked and felt cheap and inferior in market places which had been largely dominated by 100% cotton). Maintaining the service life of cotton rich still requires careful precautions regarding use of sodium hypochlorite in the countries where this is still permitted for stain removal, because the cotton content is still susceptible to premature rotting and the polyester poses other problems for effective stain removal.

Measuring linen life

In well-run, high-volume textile rental plants, linen life can now be routinely monitored without time-consuming stocktakes. The total number of issues for each classification should be totalled, on the normal production flowsheets, over a period of say three or six months. The totals are then divided by the number of new items of each classification that have had to be injected to maintain the service over the same period.

For example: if the number of king-sized duvet covers issued over six months is 5,093,471 and the number of new covers injected is 51,192, then:

Average life of a king-sized duvet cover = 5,093,471 ÷ 51,192 = 99 wash and use cycles.

This is possibly not untypical for this classification, but those who have learned to monitor in this way have acquired the first vital tool to getting control of linen life.

Linen life vs care in handling

Rental customers generally take less care of rental linen than they would if they owned it themselves and laundries’ customer care teams are often timid about taking them to task, even for gross carelessness and damaging habits. Serial cases of ‘bag drag’ and ‘floor cloth applications’ still occur and lead to progressive ruination of entire stocks of duvets (used as a sack to get linen from the guest room to the soiled storage area) and towels (used to clean the bathroom and its floor). Market leaders have learned to identify the classic symptoms of these and to tactfully explain the effect of these to hotel management.

The laundry itself is frequently to blame for other forms of careless handling. Every item dropped onto the laundry floor has the potential for creating an irremovable stain (euphemistically termed a ‘floor mark’) and consequent avoidable ragging. This is a widespread problem which too few laundry managers have tackled effectively. Likewise, damaged laundry cages create sharp snagging points and jagged edges, which initiate tears and holes on a regular basis, if not dealt with immediately and correctly.

Laundries which have started to move from 100 wash-and-use cycles towards 150 cycles have already demonstrated the value of these vital first steps.

Linen life vs stain removal for 100% cotton and cotton-rich

Those still using sodium hypochlorite for stain removal will have found that over-dosing causes rapid reduction in the tear strength of 100% cotton sheeting and excessive linting and premature ragging of cotton towels. What is not so obvious is that even using the correct dosage at too high a temperature can cause just as much damage. This is a particular problem in tunnel washers, which use recycled water from the press tank and from the start of the rinse zone, for the recycle back to the pre-wash. If this liquor contains unused hypochlorite and the pre-wash gets above 40C then avoidable damage will still occur, every minute of every day. The secret is to keep the pre-wash below 40C, to ensure the softening of protein stains, so that these all come away in the main wash. This helps to avoid immediate weakening of 100% cotton and loss of cotton from cotton rich.

Maintaining ironer productivity for cotton rich

The polyester content of cotton rich means that it leaves the de-watering stage after washing with a much lower moisture retention than 100% cotton. This in turn leads to lower energy costs in drying and ironing of sheets, duvet covers and pillowcases. It also offers greater productivity from the ironer, because each item needs less energy and therefore it should be possible to process more items per working hour.

This is absolutely true, but this cannot be achieved using the same bed temperature as that used for cotton, because polyester is thermoplastic, which means that it softens and loses its strength progressively above about 170 – 175C. Trying to iron cotton rich at the temperatures generated by 10 or 12 bar steam will cause it to lose its strength and allow elongation in the direction of feeding through the ironer. Unfortunately, this stretch is not relaxed out by the next wash and over the succeeding 20 – 25 washes the item becomes permanently distorted. A sheet fed in conventionally, widthways, will become wider and it will ‘neck in’ in the length, to the extent that the sheet ultimately cannot be tucked in top and bottom on the bed.

The correct solution to this problem is to lower the ironer bed temperature to that of 8 bar steam and to maintain ironer productivity by other means (such as edge to edge feeding, maintenance of good vacuum to the rolls, perfect roll to bed contact by careful control of the diameter of the clothed rolls and so on). It is not sensible to buy sheeted items which are say 20% longer to compensate for the perceived ‘shrinkage’, because the cost of multiple washing of the extra fabric will wipe out much of the advantages of cotton rich. There is no point in raising a complaint with the supplier of the fabric, because the fault lies with the launderer, not with the cloth maker or the sheet producer.

Maintaining linen life while dealing with Covid-19

Although Covid-19 is sensitive to sodium hypochlorite, the concentrations used in bleaching are not sufficient to deal with it in any way effectively. Wash processes designed to control Covid-19 rely on other mechanisms which have nothing to do with stain removal. The market leaders for supply of wash chemicals each have their own certified systems, some of which are patented. The best approach to be taken is to try out one or more of these novel systems (which may well include novel bleaching techniques as well). Several are also advertised as promoting extended linen life. Now is the time to be implementing the results of these various pieces of research. This will not only deal with Covid-19 in an assured manner, but overall disinfection will be achieved in markets where this has not been routinely obtained to date. This will be of significant benefit to many care homes, cruise lines and hotel operators.

Effect of theft on linen life

Theft has a devastating effect on linen life, because every item stolen or hidden away in a hotel store for ‘emergencies’ or diverted for misuse elsewhere, represents yet one more item which must be immediately replaced with a new injection by the rental operator in order to maintain today’s deliveries. Theft will be tackled in a future issue of LCN.

Conclusion

Increasing linen life significantly does not require a degree in rocket science. It simply needs systematic and disciplined attention to detail, following the advice given this month. The journey from 100 to 150 wash and use cycles is usually the easiest, after which the demonstrable savings drive an organisation on to the 200-cycle target. Good luck!

If you have 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

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