Tumble dryers are machines used for drying garment after wet process on jeans. Garment do not came directly to dryers from washers but first they are treated in hydro extraction machines. These machine are very much similar to spinners provided in home laundry washing machines. Drying lot more depend on the extent to witch water is extracted form garment before adding to dryers.
The tumble dryers works by blowing hot air through garments. Garment are constantly tumbled in machine during dying process and hot air is blown through. This helps to evaporate the water contained in garments and let them dry in shorter time in comparison to drying in sunlight.
One very important fact about tumble drying is it make the garment soft due to mechanical stroking of rotary drum of tumbler. The garments get little soft even in unwashed case, when run in dryer for 40 to 60 minutes. In new developments, where the garment is not to go through wet processing, only tumble drying helps to make the garment little clean and soft.
Some time silicon balls are added in drying process to soften the garments. This treatment is usually done to the articles where wash is not required. These unwashed garments are processed in dryer with silicon balls for 40 to 60 minute and the mechanical rubbing and strokes of heavy balls break the hardness of the fabric. Some time heavy rubber balls instead of silicon are used and have the same results. Low quality rubber balls may transfer their color to light shade garments so it is always recommended to uses silicon balls if the cost is not big deal.
Drying has a great impact on measurements and can be controlled to a considerable limit by changing conditions in dryers. By increasing the run time in dryer, measurements can be shifted towards more shrinkage and vice versa Also the temperature of the dryer is important and has the same effect i.e higher is the temperature more is the shrinkage and measurements shift to minus. So it is important to keep the run time for on production to good control.
Dryer time as discussed is subjected to the amount of water contained after extraction process. If the water extraction in spinner is done to maximum then it will obviously take less time in drying and vice versa. Some time it is done so to keep the garment in open well ventilated area for around one hour then it will further reduce the running time for dryer and the effect of heat will be lesser on garment. This will result to minimum shrinkage.
Keeping the garments in open for long time before adding to dryer may leave stains (water marks) on garment. These marks can simply be washed out by rinsing in tap water. To a little extent, shade losses during drying process due to rubbing. This can be avoid by doing the garment â€œinside outâ€. This will not only help to avoid shade fading but also to prevent buttons and rivets to get scratched.
Number of garment in one drying batch has its own effects on shade and shrinkage. By reducing the drying batch size, its not only to reduce the running time to control shrinkage but will keep the garment more clean and bright. Increasing the batch size will result to more rubbing of garments during tumbling and will make the garment more dull and less bright.
In case of light shade especially in bleach washes, excessive heat treatment in dryer will change the color to more pale and ditty look. Milky white will turn to light off white and blue to little grey. But when it comes out it looks brighter in all aspects of color due to excited state of color structure molecules at high temperature. Its comes to regular tone after cooling down. So it is compulsory to let the garment cool down before checking the shade or measurements.
- Excessive heat treatment will leads to more shrinkage of garment.
- Maximum extraction of water before drying will minimize the drying time. (result to less shrinkage)
- â€œInside outâ€ drying will help to retain the shade and also avoid scratches on buttons and rivets.
- Small batch size will keep the garment clean and bright.
- Over time heating in dryers will pale the bright areas.
- Silicon or rubber balls can be used on unwashed garment for softening