Manufacturer · Fashion & Home Accessories
Elastic loses its stretch when the elastic threads in it are damaged or broken. The most common causes are washing and drying at high temperatures, chlorine and harsh detergents, sunlight, constant heavy stretching and choosing the wrong elastic for the product. Some of the causes depend on the manufacturer, others on care.
How elastic works and why it gets tired
Every elastic contains two groups of threads: elastic ones (natural rubber or elastane) and covering ones (polyester, polyamide or cotton). The elastic threads provide the tension, while the covering threads form the tape and protect it. When the elastic threads age, break or lose their properties, the elastic no longer returns to its original length. This shows up as wavy, stretched-out or rolled elastic.
The main reasons elastic goes slack
1. High temperature
Heat is the main enemy of elastic threads. Washing at 60 °C and above, tumble drying on a high setting, drying on a radiator and ironing with a hot iron directly on the elastic accelerate ageing. Rubber thread is particularly sensitive; elastane tolerates heat better, but it too has limits.
2. Chlorine and harsh detergents
Bleach, chlorine-based products and swimming pool water damage both rubber and elastane. That is why swimwear and poolwear are sewn with elastics made with special chlorine-resistant threads.
3. Sunlight, oils and creams
UV rays, body oils, creams and sweat gradually break down rubber thread. This is one of the reasons lingerie and sportswear are sewn mainly with elastane.
4. Constant overloading
If the elastic is too short or too weak for the product, it works constantly close to its maximum stretch. This tires it much faster. Heavy fabric, lots of pockets and a tool belt are typical examples of overloading.
5. Pierced elastic threads
A straight stitch through stretched elastic, a blunt needle or a woven-fabric needle instead of a jersey needle can cut the elastic threads. The elastic looks fine on delivery but loses strength after the very first wear.
6. Old stock
Elastic, especially rubber elastic, also ages while in storage – in light, heat or near electric motors. Reels stored for years in poor conditions may have lost some of their tension even before cutting.
Elastic losing stretch: what the manufacturer can do
| Problem | Production solution |
|---|---|
| High-temperature washing | Elastic with elastane instead of rubber |
| Heavy fabric, waistband drops | Wider woven elastic with strong tension |
| The elastic rolls | Ribbed woven elastic, casing cut to size |
| Broken threads when sewing | Jersey needle, stretch stitch |
| Swimwear and pool | Chlorine-resistant elastic |
| Old stock | Stock rotation, proper storage |
Dense woven elastic protects the elastic threads from friction better, because they are wrapped and held in place by the covering threads. That is why, on products that are washed often, it usually lasts longer than a soft knitted elastic with the same composition.
The care label is also part of the solution
Many complaints about slack elastic come from incorrect care. If the product has rubber elastic, the label should not allow washing at 60 °C or tumble drying on a high setting. State a realistic temperature, "do not bleach" and "iron on low" when the elastic requires it. This protects both the customer and the brand.
Tips for the consumer
- wash garments with elastic at 30–40 °C, unless the label allows more;
- do not use bleach or chlorine-based products;
- line dry rather than on a radiator or in a tumble dryer on a high setting;
- do not iron directly on the elastic;
- rinse swimwear in clean water immediately after the pool.
How to check the elastic before the series
- Measure a piece of elastic at rest, stretch it to the maximum several times and measure again – a good elastic returns almost completely.
- Sew a test garment and wash it several times at the temperature on the label.
- Dry it the way the customer will and check the length and tension.
- Compare samples with elastane and with rubber if you are unsure which type to choose.
You will find more about the different constructions in the elastics section.
Knitted or woven – does it matter for loss of stretch
The type of construction affects how the elastic "ages" visually. With soft knitted elastic, loss of tension quickly shows as a wavy, stretched edge. Woven elastic holds its shape longer, because the crosswise thread prevents the tape from stretching widthwise and deforming. That is why woven elastic is usually the safer choice for heavily loaded waistbands that must look good for a long time. For fine lingerie edges, soft knitted elastic remains suitable, but it is important that it contains elastane and is sewn with a stretch stitch.
Can slack elastic be restored
Unfortunately not. Broken or damaged elastic threads cannot be restored. A temporary solution is to shorten the elastic in the casing, but it will continue to lose strength. The only lasting solution is replacing it with new elastic – in series production, this means choosing the right elastic from the start.
Quality elastic from Polkom
Polkom is a Sofia-based manufacturer and wholesaler of haberdashery. We help brands and factories choose elastic according to the fabric, care and load, with samples before the series and delivery across the EU. Describe the product and the problem you have encountered using our inquiry form.
