There has been a significant surge in the use of duvet covers over the past ten years, both in the hospitality and the care home sectors.
Duvets and duvet covers have many advantages – the speed and ease of making the bed, the reduction in textile stock holding and lower laundry costs (because there are fewer items to be processed). So they are here to stay for many more years.
The duvet itself should be routinely washed but users often overlook this so they are only washed infrequently at best.
The laundry industry has had to adapt handling and processing procedures for duvet covers, which can be very difficult to handle and finish correctly – and especially where incorrect fabric or construction methods are used in their production.
The first factor that launderers should consider is the type and quality of fabric used to make the duvet cover.
Most covers are essentially a bag that has been made up by taking a “double length” of fabric, simply folding it in half across the width and stitching the selvedges together. During laundering and whilst in use, the stresses and strains placed on the fabric will often be considerably greater than those placed on a simple flat sheet.
This means that a much stronger fabric is required and the way it is constructed is critical to achieving the optimum fabric life by minimising the risk of splits and tears. For this reason, most fabrics used to produce duvet covers are polyester-cotton blends rather than 100% cotton.
It is important that the thread count in the fabric used is not too high. The thread count refers to the total number of yarns used per square inch in the warp and weft.
The more the thread count exceeds 200, the lower the permeability of the fabric as the yarns are packed more tightly together.
This will significantly restrict the way that both water and air can pass through the fabric.
As the duvet cover is essentially a “bag”, air can become trapped in the cover during the wash process to create a “ballooning” effect. This is not critical if the duvet cover is processed in a washer-extractor but in a tunnel-washer ballooning will cause blockages and disrupt production.
This risk can be minimised by pre-washing the duvet cover correctly to remove the manufacturer’s sizing before it is first issued. A special process is needed for this pre-wash.
During water-extraction, especially with membrane presses, slugs of water and air trapped in the duvet cover can lead to bursts, splits and pin-hole damage as the press forces the water and air through the fabric. Tuning the press program to include a slower ramp-up to final pressure, sometimes with one or more tamps, can reduce this risk.
Ideally, the duvet cover fabric should be a polyester-cotton blend of 140 – 160gsm with no more than a 200 thread count. An 80:20 or 70:30 cotton-rich fabric should give both strength and breathability.
The next consideration is the trend towards the use of sateen stripe or “self-stripe” fabrics. These types of fabric are manufactured by altering the configuration of the warp and weft yarns at regular intervals to produce the desired stripe effect.
Where the stripes run along the length (warp) of the fabric, there is a small gap between the warp yarns at the junction of each stripe. As the fabric gets older and becomes worn, the flexing and mechanical action of the wash process will increase the risk of the fabric splitting at this junction in the warp yarns.
There is no tamping or compacting action to the warp yarns during the weaving process – this only happens to the inserted weft yarns.
When the self-stripe is produced across the width (weft) of the fabric, the risk of splitting is significantly reduced as the weft yarns are “tamped” together tightly and yarn movement is minimised. However, the length of the duvet cover may be reduced if the stripes are required to run down the length of the bed (a limitation imposed by the weaving loom width).
Producing strong pillowslips by this technique is not a problem.
The duvet cover’s construction also plays an important part in achieving both the correct appearance and maximum fabric life. The type of stitching, seams and the quality of the thread and type/placement of bar-tacking are all important and must be specified when purchasing.
Because of the tensions on the seams during both washing and finishing, it is essential that a good quality thread is used. A core-spun polyester is ideal. The stitch seam bite into the fabric is sufficient to minimise the risk of yarn slippage, which can lead to the seams “opening” when placed under tension as the warp threads separate from each other.
To reduce the risk of seams tearing, bar-tacking should be used on all junctions – especially at the opening end of the duvet cover and around any hand-hold inserts placed in the side seams at the closed end.
Frequently, in the interests of speed and economy, some manufacturers may only place two or three lines of stitching (forward and reverse stitching for 1– 2cm) at these high stress points. These can frequently tear.
It is also essential that there is no bowing or skewing of the fabric when the duvet cover is manufactured and that the side-seams are perfectly aligned with each other.
Any lack of straightness in the warp or the weft will present major problems during ironing. There are simple techniques for checking this upon receipt of the goods.
The slightest variation in the continuity of the fabric – alignment or skewing of side-seams, for example – will lead to a duvet cover that twists and results in side-seam creasing or severe creasing at the open end of the duvet cover. The latter will occur when launderers attempt to feed the duvet cover “closed-end” first into a multi-roll ironer to avoid “ballooning” as, if there are no hand holes, the trapped air is forced to the opposite end of the duvet cover.
It is therefore essential that all deliveries of new duvet covers are assessed before the covers are introduced into the system.
Physical examination
Such assessment should involve the physical examination of three or four duvet covers taken at random from the consignment to check the following:
• Side-seam stitch alignment:
Have the side seams been stitched in a straight line and does this line of stitching follow the warp yarns? This normally involves tearing the fabric down the length (warp) adjacent to the seam to ensure the stitch line is straight.
• Measure the dimensions:
Check both top and bottom width and both side seam lengths before and after washing and finishing. This should be done at least three times, using a normal wash process each time. This will identify whether any unwanted fabric sizing has been used, as well as the extent of the dimensional changes
caused by both wash and relaxation shrinkage.
• Examination of all openings:
Careful examination will ensure the correct bar-tacking has taken place and there is sufficient seam “grin” (where lateral tension is applied to the side-seams). Ensure that the fabric edges are correctly over-locked and secured to reduce the risk of splitting.
It is also worth noting that there is a significant amount of fabric entering the market that has not been fully “pre-shrunk”. This partially pre-shrunk fabric is a lot cheaper to produce.
However, although the fabric will often only shrink by the standard 7% permitted (5% wash/relaxation shrinkage plus 2% heat shrinkage for polyester-cotton blends) during the first three wash cycles, it will continue to shrink over the next 25 washes. In LTC’s experience, dimensions can change by much as 24% in total. Clearly, this shrinkage level is unacceptable for any textile but it may take some six to nine months for the excessive shrinkage to become apparent, by which time there is very little point in complaining to the manufacturers.
A test cycle of 25 washes/finishes might seem prohibitive and time-consuming but knowing that the investment is justified and that the fabric will provide the required life expectancy is invaluable.
If there is a fault, the consignment, can be returned to the manufacturer before it is introduced into a system.
There may well be other latent defects with the fabric or in the construction. So as part of the checking procedure, it is highly advisable to take five items from each consignment/batch, identify them with both their order number and the date and then store them for future reference.
If after nine months there are no problems with the items placed into circulation, then those items held for reference can be introduced into the system.
If defects do occur, then at least there are five new items from the consignment that can then be subjected to closer scrutiny and tested to determine if the fault was caused by a manufacturing defect.
