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Timetables
Working hours: 09.30 / 12.30 - 16.00 / 18.00 From Monday to Friday.
Purpose of processing
This processing is achievable with three process modes which differ in duration of the
processing and for the type of effects produced:
discontinuous decatising at atmospheric pressure;
continuous decatising at atmospheric pressure;
discontinuous decatising in an autoclave.
Whatever the modality, decatizing substantially modifies the hand of the fabric
according to the support on which the piece is placed, called "under piece":
the thick, soft and hairy “flannel” type under-piece gives a woolly and soft hand;
the “setino” type under-piece gives a shiny, rather flattened, silky and stable effect.
Process that gives the fabric a full, compact and sustained hand, also giving a light touch
dimensional stability and allowing the elimination of any resulting excessive gloss
from calendering.
Processing technology
The machine consists of two sides on which the decatizing cylinder is placed (see figure A, point 1) - in stainless steel or copper, with many small holes on its entire surface, to which tubes are applied, facing the inside the cylinder, which collect any condensate - and a
small cylinder on which the under-piece fabric is wrapped (fig. A, 2) for which the "setino" (compact and thin) or the "mollettone" (soft and thick due to the raising
suffered on both sides), chosen according to the type of fabric to be treated and the desired effect, considering
that a greater rigidity of the sub-piece gives the fabric a more nervous, snappy and shiny hand.
The operation begins by wrapping together the blanket and the fabric to be treated on the decatting cylinder
they are kept tightly adherent by an adjustable pressure roller (fig. A, 3). At the end of the rolling up, steam is introduced into the cylinder which, passing through the holes, hits and crosses the blanket and fabric rolled together for the time that the operator deems appropriate. Once the steam flow is closed, a pump is activated which, sucking air through the holes in the decatitor cylinder,
determines the cooling of the two fabrics and a more sustained hand. During these two
phases (introduction of steam and activation of the pump), the decat roller maintains a constant movement of alternating rotation, to move the fabric and facilitate the penetration of steam and air. Outside the machine there may be an air cooler (fig. A, 4) with the purpose of bringing the fabric to room temperature. The machine is completed by a suction system, which eliminates the vapors that come out of the roll formed on the drum.
Finally, the treated fabric is removed while the blanket is rewound on the appropriate cylinder.
The characteristics assumed by the fabrics after this treatment will depend on
choice of fabric under the piece,
steam delivery time, cooling time.
Longer steam administration time and less suction with the pump give
a softer hand to the fabric; the opposite treatment, on the other hand, will cause the fabric to assume one
harder hand.
Execution of processing
The trial clerk must:
carefully pair the fabric to be decat with the blanket;
program and control working times and parameters with the control panel
(steam injection, pressure of the pressing cylinder, steam suction).
Most recurring defects
Horizontal wrinkling of the fabric due to low fabric tension and undercut during
the winding. This defect becomes evident during the aspiration phase.
Different vertical aspect on the decatito fabric, near one of the two selvedges, which
it appears untreated due to irregular wrapping at the entry of the piece with the under-piece,
going out of the same.
DISCONTINUOUS DECATISING IN AUTOCLAVE (KD)
Purpose of processing
The technological solutions for decatising in discontinuous autoclave are different. This card
presents the most used system in the Prato textile district, the so-called KD: machine that obtains
results and effects similar to discontinuous decatising, i.e. more sustained hand, more thickness
low, greater dimensional stabilization compared to an environmental pressure treatment,
with a greater guarantee on eligible returns for the packager.
It mainly deals with woolen and mixed wool fabrics, both carded and combed.
Processing technology
The main processing stages are three:
preparation of the roll of pieces to be inserted in the autoclave.
In the most recent models, the preparation of the roll on the decatitor is electronically controlled,
in particular the tension of the blanket and the centering to avoid selvedge center defects. In
older machines the rolling operation (of the fabric and of the blanket) still comes
performed manually by the operator.
Insertion of the roll of pieces in the autoclave and decatising operation under pressure.
The roller, sliding on special guides, is introduced into the autoclave and the door hermetically closed.
In the decatector cylinder an aspiration system allows the steam under vacuum to
quickly cross all the layers of the roll, but only when all the air contained in the autoclave
has been expelled from this decatising begins and the fabric is subjected to the action
steam under pressure.
The result is determined by the duration of processing and the steam pressure, parameters
these which are set from the control panel. The steam is then discharged through a
special conduit.
Extraction of the roll of patches and separation of the decat patches from the blanket.
Once decatizing is completed, the trolley with the roll is extracted and taken to the preparation machine
and put into storage. Meanwhile a second roll has already been prepared to be
placed in the autoclave, thus leaving the place in the rails to bring the already decatized roller into the
unloading position (same place where the roller is prepared in the decatizing cylinder).
The blanket is separated from the decatitated fabric and wrapped on a beam, while the piece is treated
it is folded or rolled up.
In more modern machines, in addition to increasing the length of the charges, they have been
semiautomatic loading systems have been introduced which allow the packaging to begin
of the new roll while the pieces already treated are unloading. Thus the car
operates with two distinct scrolls.
Depending on the models and the type of fabric to be treated, the hourly production varies from 600 to 2000 meters.
Execution of processing
The operator's behavior in the face of the problems of this process does not differ
from what has already been said about discontinuous decatising at atmospheric pressure.
Most recurring defects
In addition to what is highlighted in relation to the discontinuous decatising at atmospheric pressure, being
of an operation carried out at high temperatures, it is evident that any manufacturing defects
they will be more evident, deeper and more fixed.
The fabrics that undergo this treatment must have good color fastness.
Labor management
The employee must:
scrupulously comply with the required process parameters;
check them on the appropriate control panel and on all control instruments (pressure gauges,
pressure gauges, drain valves, etc.) present on the machine.
Services
After the sale of the machinery we also assist you in logistics and if desired by the customer we have technicians capable of reassembling and starting the machinery.