UNIVAP : Continuous steaming machine for HIGH BULK acrylic yarns

This steaming treatment is for the development of bulk in the yarns. The development of bulk is affected by several factors i.e. the amount of twist in the yarn, the proportion of high-shrink fibres, fibre length, shrinkage rate (from 10% to 50%) etc.

The principle, unique to SUPERBA, involves using one single steaming chamber per machine to guarantee a regular shrinking and a homogeneous quality from yarn to yarn. At the exit of the steaming chamber, the yarn runs through a cooling zone before being wound-up, at ambient temperature, thereby retaining its bulk.

Advantages of the process

• Low energy consumption
  
• Minimum maintenance / cleaning
  
• Exceptional regularity and shrinking of the fibres
  
• Extended treated yarns range

Running principles

The processing line comprises three sections :

• a creel on which are located the feed packages to ensure continuous feeding,
  
• UNIVAP machine with 10 spindles/tracks running one end per spindle,
  
• winding machine - either with or without automatic doffing. The take-up can either be conical or cylindrical with 6’’ or 8’’ traverse.

Each yarn coming from the creel is threaded pneumatically into a laying head (one per spindle) at the entrance of the machine. The yarn is then wound around a special spindle at a speed of up to 1500m/min. The coils formed around the spindle are then laid down onto conveyor belt which carries the yarn into the steaming chamber. The speed of the conveyor belt can be adjusted from 4-11m/min. The yarn coils enter the steaming chamber and the shrinking of the HB fibres is immediate due to the thermal shock. Inside the chamber the steam flow is driven above and underneath each conveyor belt by two injectors.

The winder can either be manual or automatic and take-up can be onto conical or cylindrical packages. At the outlet of the UNIVAP machine there is a photo-electric cell over each conveyor belt. This ensures that the spindle of the steaming machine is synchronised with that of the corresponding winder, which thereby allows the autonomous operation of the " steaming-winding " line. For the treatment of pre-dyed HB acrylic yarns we recommend the use of the ADS softening device. Together with the saturated steam it allows the yarns to develop a very soft handle