shrinkage dryer CA-85
CA-85 dryer represents an important step in the improvement of drying
technology, specifically to process both tubular and open width
knitted fabrics, and also a wide variety of woven and non-woven
ALEA, textile drying specialists since 1881, have designed this
machine to meet the growing demands for "dimensional stability"
and "improved handle" of knitted fabrics.
would like to point out the main technical features of this machine
designed to resist mechanical and thermal stress
designed to minimize heat losses
circulation: designed to produce symmetrical ariflow with minimal
pressure drops. Re-circulated air is filtered, heated, and blown
by high performance fans into delivery channels
nozzles: they are specifically designed to create a warm air vibrating
cushion in which the drying process takes place with excellent
output. The symmetrical airflow holds the fabric in open, crease-free
form with selvedges uncurled
system: machine can be supplied for heating by steam, superheated
water, diathermic oil, or direct gas
system: for machines with standard filters damp air is exhausted
via ductwork fitted with butterfly valve to control quantity of
exhausted moist air
drying temperature is maintained at preset values by a temperature
controller with automatic control valves. Fabric speed is controlled
by a DC drive system, easily adjusted by potentiometer from the
operative position. A DC driven feed roller provides overfeed
adjustment between -10% and +40% according to fabric shrinkage.
Fabric take-off is also by DC drive and both overfeed and take-off
are adjustable by potentiometer from the operative position. Speed
ratio between feed and take-off is automatically maintained when
fabric speed is adjusted
steel conveyor belt: designed for strength and to allow maximum
airflow. The belt is driven directly by sprockets running the
width of the machine, thus avoiding the need for belt centering
motors: they ensure smooth running and perfect synchronisation
of overfeed speed and take-off speed.
first picture shows the outlet side of a machine comprising three
chambers, each of three meters length, heated with diathermic oil
and specifically designed to dry silk fabrics.
second picture shows one of many plants set up in the United States.
It comprises four dryers, each with four sections. Modularity is
one of the advantages of the CA-85. Additional chambers may be added
to the original machine at later stages to provide an ultimate of
six section machine.
other pictures show:
Detail of the stainless steel belt and the fabric as it is conveyed
during drying. Note that the belt mesh is very open, thus avoiding
any reduction in airflow to the underside of the fabric. Hence,
this ensures uniform drying to both side of the fabric. In fact
the design of the mesh is such as to straighten the airflow and
direct it on to the fabric.
Fabric laid out on the belt inside the dryer. Notice the "wavelength"
of the fabric, which can be varied by adjusting the inlet overfeed.
The combination of air agitation, temperature and moisture in the
fabric allow the knitted fabric to relax in tensionless form to
its natural state, giving improved dimensional stability.
Note also that the wave motion of the fabric avoids permanent contact
with the belt and possible marking.
of the inlet equipped with expander for light and open fabrics.
selection of a CA-85. It can be supplied with 1600, 2000, 2400 or
2800 mm useful width.
section of one CA-85 chamber.
The picture shows the position of air filters and heating batteries.
Both are easily accessible for cleaning and maintenance.
passing through the moist fabric, air is re-circulated by fans,
blown by filters for lint removal, then via heat exchangers or gas
burner chambers. The reheated air is then directed once again on
to the fabric via the special nozzle system fitted above and below
the stainless steel belt. The proportion of moist air exhausted
via the chimney or exhaust duct is controlled by a butterly valve.
view of a three chamber CA-85 with inlet overfeed roller and outlet
plaiter. The picture shows the large doors on both sides of the
machines for easy access to inner parts.
view of a CA-85 with 2800 mm belt useful width. Of course, the total
width of the dryer varies according to the belt useful width.