Dryers for loose stock, tow/top slivers and yarns in hanks
Textile applications
"LTRF 60 kW" dryer for cotton loose stock for mélange, with volumetric hopper feeder and unloading with pneumatic transport to storage.
"LTRF 60 kW" dryer for wool loose stock.
"LTRF 2x60 kW" dryer for cotton and rayon knitting yarns in hank form.
"RF" series dryers
Dryers of the "RF" series, similar to those used for the drying of packages and tops, are widely utilised for the drying of yarns in hank form, unwound tow/top slivers, loose stock and other "loose" textile products.
Hanks, after dyeing and centrifugal hydroextraction or in-line squeezing, can be perfectly dried without any movement or passing air flow, thus avoiding yarn entanglement - which is a typical problem in hot air dryers - and making the winding operation more efficient.
Tow slivers, after dyeing and hydroextraction in the form of pressed cakes, and tops slivers, dyed and hydroextracted in "big forms" or dyed as standard bobbins/bumps, back-washed and squeezed, can be dried folded up on the conveyor belt of the RF dryer: a perfect residual moisture distribution is obtained within the slivers, resulting in an increased efficiency of the tow stretch-breaking or top intersecting / re-combing operations.
The RF drying of loose stock after carbonising, bleaching or dyeing and batch or continuous centrifugal hydroextraction, has many advantages as well. The fibres can be loaded (manually or by means of fibre openers and volumetric hopper feeders) directly onto the conveyor belt of the dryer or even inside permeable bags used for the dyeing and hydroextraction operations; the reduced losses of product, the uniformity of drying, the improved physical-mechanical characteristics of the fibres, and consequently the more efficient carding - combing - spinning operations, result in a higher yarn metric yield of up to 2%.
"LTRF" and "RFA/S" series dryers
The "LTRF" (Low Temperature Radio Frequency) series dryers are especially designed for the low temperature drying of all “loose” textile products.
As far as the radio frequency generation and application sections are concerned, these dryers derive directly from the "RF" series equipment. The innovation consists in the additional air suction and blowing compartments, placed just beneath the conveyor belt, which are fitted with medium-head centrifugal fans. These compartments force a controlled amount of air - generally recovered from the triode cooling system - through the product being submitted to the RF field, so that the drying process takes place at temperatures which normally do not exceed 60-70°C.
The air passing through the product improves the energetic efficiency as well, so that drying costs are reduced by 15-30% when compared to the standard "RF" technology.
An original version of these dryers is the "RFA/S" series. Here, the principles of both the "RFA" and "LTRF" technologies are combined; the forced air flowing through the product and the accurate temperature control inside the drying tunnel allow us to set all parameters of the evaporative process. Both the product quality and the energetic efficiency are improved, and savings in drying costs up to 35% in comparison with the standard "RF" technology are obtained.
Several "LTRF" and "RFA/S" series dryers installed worldwide since the mid nineties have proved their effectiveness with a wide range of products like: cotton, wool and cashmere loose stock, fine wool tops slivers, acrylic tow, silk hanks, cashmere, lambswool and other fine wool yarns in hank form, wool and nylon "jumbo" hanks for carpets, cotton, mercerised cotton and rayon yarns for knitting, sewing and embroidery, etc.