Making the right choices for rental textiles

In a well-run rental operation where bed and bath linen lasts for around 175 wash and use cycles, textile purchase costs should be around 10% of turnover, but in operations with a shorter textile life these costs account for around 20%
Making the wrong choice pushes costs even higher as it can lead to complaints about faults, such as cracked ice creasing, pilling, holes and tears or harsh towels, which accelerate the need for replacements.

Cotton types
There are over twenty major cotton growing areas worldwide and in each production is influenced by the weather, the type of cotton plant that will thrive and processing methods, so the variation is s significant. The quality types are defined length of fibre, rather than the geographic source and type of cotton is known as American makes up the bulk of rental linen. However, the premium end of the rental market will frequently demand the demonstrably higher quality given by the longer staple lengths found in Pima and Egyptian cottons.

Yarns
The majority of rental sheeting requirements can be met by cotton-rich fabrics with a 20 or 30% polyester content but to get the full benefit of increased textile life, the polyester must be spun into both warp and weft yarns as an intimate blend to increase strength in both directions.
The other benefits of such blends are lower laundering costs as cotton-rich fabrics are easier to dry than cotton, higher productivity and a fabric that is more comfortable for the end user than 50/50 polycotton.
Yarn twist determines several factors. A high twist gives a stronger fabric, with less tendency to pilling but the clother is harder with less drape. A low twist gives a much softer fabric but the risk of pilling increases.

Ends and picks
Both the weave quality and the cost are defined by the number of warp threads per cm running down the roll of cloth (the 'ends') and the number of weft threads running across it (the 'picks'). The dominant factor in many cloths is the number of weft threads, because that governs weaving time.
Cloths with a high number of threads per square cm (or square inch, both are used) have become fashionable and are frequently sought by prestigious hotels. A 200TC cloth is one in which the sum of the warp and weft threads in a square inch totals 200.
If this is achieved in a plain weave (one over, one under in both directions) then the result is a fine cloth which drapes well. If the customer demands say 500TC or even 800TC the weaver and the renter have a problem in packing enough threads into a square inch with plain weave and single threads.
The solutions and their perceived quality vary. Some weavers will twist two single yarns together and weave them as one; some will feed an untwisted bunch of four yarns together to form the weft (a 'quadruple pick insertion') and others will opt for a different weave (for example a sateen weave, in which one weft yarn might travel over four warp yarns). The results vary widely especially in stability in ironing, elasticity and progressive distortion over multiple laundering processes.

Sizing
Some form of starching or sizing is applied to assist weaving at two stages in the process. Firstly, sizing must be applied to the warp yarns when they are wound onto the weaver's beam. This improves yarn strength, giving fewer breaks) and reduces the friction between the warp threads and the shuttle, to avoid burning the yarns. The warp sizing is removed if necessary when the cloth is de-sized in finishing. If the sizing has any plastic constituents that are not removed in laundering then it must be removed, otherwise the cloth will suffer from cracked-ice creasing for the first twenty washes or so. This is because after the fabric has been washed, the sizing becomes deformed during extraction and will stay that way until it gradually chips away over several washes - a very slow process.
One common component of warp sizing is polyvinyl alcohol (PVA). This dissolves very easily in de-sizing, given adequate water and time but once the fabric has been heat-set in the finisher's stenter the PVA cross-links, sets around the fibres and threads and becomes almost impossible to remove. Any natural starch in the sizing recipe will also be captured and will not come off in laundering. Weavers understand this very well but may need a reminder from time to time.
The cloth maker will usually apply a light dressing to make the fabric easier to handle through cut, make and trim, to give square cutting out and straight seams with no run-out. This is fine.
However, very occasionally LTC comes across batches that have been bulked up with additional size. A 120gsm fabric can be bulked up to 140gsm in this way, so renters need to be wary.'

Shrinkage
It is important that any shrinkage during washing is allowed for when the fabric is cut into sheets or duvet covers. If no allowance is made then after four or five laundry washes, the sheets and covers may no longer fit the bed or duvet.
The cloth finisher can avoid excessive shrinkage in washing by relaxing the fabric in wet finishing and then taking care to avoid overstretching it (either in length or width) during the final setting in the high temperature stenter.
There is no British or International Standard for the allowable shrinkage in industrial laundering of hospitality textiles, but BSI has published a European draft for development for healthcare textiles (DD ENV 14237) and this also works well for hospitality textiles. This allows the cloth maker shrinkage of up to 7% (5% wash shrinkage plus 2% heat shrinkage) in each direction for cotton-rich fabrics.
When handling cotton-rich fabrics it is important not to confuse wash shrinkage with the distortion caused by high ironer bed temperatures roll-to-roll stretch and fabric-to-bed drag with wash shrinkage. These distortions are a separate matter and beyond the scope of this article.

Fabric strength
Weak fabric can tear and go into holes very readily when it is less than half way through its useful life. The healthcare textiles standard DD ENV 14237 calls for minimum tenacity of 400N per 50mm strip in both warp and weft. This is a very good compromise between what is economically achievable and over- or under-specification.
Fabrics with this initial tenacity should easily give 200 wash and use cycles with correct bleaching before weakness becomes an issue and some launderers can achieve much more than this.
The industry average life for a double sheet or duvet is believed to be only 110 wash and use cycles. This includes early replacement due to theft or abuse, but even so there is much achieve in terms of prolonging textile life.

Colour changes in washing
Most fabric suppliers will bleach cotton to give good whiteness and add an optical brightening agent (OBA) to enhance the fluorescence in natural daylight. OBAs are expensive and if the fabric is being made to a tight price, there may be a temptation to use a cheap OBA, such as one used for paper, rather than a good quality textile OBA.
Frequently the use of cheap OBA's results in a clash between the one on the cloth and that used in the detergent. This combination often produces a white, with a yellow, pink blue or green tinge which becomes marked after a few washes then slowly fades. Very strong bleaching will reverse the colour shift but it will shorten fabric life.

Checking new textiles
It is important that staff receiving new textile batches make some very basic checks to avoid problems arising once the linen has gone into circulation as it is then difficult to get suppliers to take responsibility. These might include:
Checking the weight of several items against the minimum - use postal scales or even domestic scales calibrated in grams.
Measuring several items in mm and checking against the minimum size specification
Checking the colour of items against the correct reference shade.

It is always worth making time to put samples through washing, ironing/drying trials to establish any potential problems with:
Wash shrinkage
Ease of ironing
Change in colour
Loss in weight (from excessive residual sizing) and so on.
If the samples fail any checks the order needs to be sent back while it is still in the cartons in which it was delivered. The supplier will be happy to accept the return because there are plenty of customers who never check anything.
If you want to keep the batches even though you have found discrepancies, then negotiate a suitable discount before you unpack the remainder.

Pointers that can help purchasing decisions

There is little point in giving a detailed draft specification here as there are so many variables that cloth designers can usually find a cheap way of making what you order. The best policy is either to order against a simple performance spec or against a small sample batch that has been tried and tested with customers.

A typical performance specification might include:
Breaking strength (minimum 400N warp and weft)
Fabric mass in gsm
Ends and picks with as close a match between the number of warp and weft threads per inch as possible (to give the least distortion in ironing)
Intimate blend of polyester and cotton warp and weft
No bulking up with extra sizing (2% maximum would be reasonable)
No residual plastic components such as PVA in the sizing
No tinting after five washes in the laundry
No pill formation from the fabric during use on the bed.

If you prefer to order against a sample, as many launderers do, then that is absolutely fine, provided the sample batch is subjected to thorough trials with customers.
These trials must check every key parameter, - shrinkage, pilling and so on is checked. You should keep labelled samples of new unwashed fabric both from the sample batch and from the bulk delivery.
Then if there are problems with the bulk, it is straightforward to check the relevant properties (according to the problems that emerge) and make a justified claim for a full rebate of the price paid.
This of course puts the onus on the cloth supplier to ensure that the bulk matches the sample in every particular, which is much better for the rental laundry customer than trying to specify every last detail beforehand.