8. Equipment for dyeing and finishing factories.
8.1. Machine for washing, bleaching and dyeing “colorado”
It is a common practice to process fabric in rope form when pre-treating and bleaching and also for washing processes following mercerising, bleaching, dyeing or printing. Part of this rope treatment is carried out on so-called through-flow or continuous winches. In comparison with other rope washing systems, these machines treat the fabric gently, i. e. no tension and negligible fiber damage. Nevertheless, there are some major drawbacks. The interchange between liquor and fabric is, as a rule, minimal; a regulation of the temperature to suit the fabric is almost impossible and the water and energy consumption is very high, because the potential of the counterflow technique cannot be fully utilised. Moreover, these machines require more operatives to supervise the fabric passage.
Fig. 8.1. The front view of the machine
The fabric dwells just as long and in an equally tensionless state as on continuous winch ranges, but in addition, on this machine, the liquor flow is controlled within each com partment and between the individual compartments. The cloth run is monitored, so that no intervention by the operatives is necessary. The consistent counterflow system with the effective intermediate squeeze extraction and the built-in counter-flow heat exchanger accomplishes a substantial reduction in water and energy consumption.
The COLORADO was designed for all those fabric qualities that can be processed in rope form. The machine is suitable for any fabric that does not crease easily, e. g. for tubular goods made of cotton, cotton/polyamide, cotton/polyester, cotton/viscose, cotton/viscose/poly ester, etc. In fact, for all those fabrics that can be rope-processed without difficulty on winches, jets or over flow machines.
The COLORADO permits counter-flow scouring and is, therefore, suitable for the following processes.
Prescouring of gray goods before further finishing processes, e. g. washing out preparations from yarn-dyed fabric, desizing of terry cloth.
Bleaching on the COLORADO articles made of cotton, cotton viscose or blends with synthetic fiber can be bleached by the immersion or "under-liquor" bleaching method. Depending on the required degree of whiteness, it is possible to integrate a reductive post-bleach or a chlorine pre-bleach stage. The fabric is bleached, washed and softened in one passage. Moreover, the COLORADO can be used for rinsing fabrics which have been bleached by other processes, such as by cold pad-store or pad-steam methods.
After mercerizing. The machine is suitable for washing to neutralise cotton knit ted fabric after caustic soda treat ment, in fact the tensionless washing process with dwell phase achieves very good results.
After dyeing. Fabric which has been dyed by the cold pad-store method can be afterwashed on the COLO RADO as can those fabrics that have been dyed by other con tinuous methods. The COLORADO is ideal in cases where winch becks or overflow machines are to be relieved of lengthy rinsing processes after dyeing.
О After printing The variable dwell time and the versatile liquor flow system make the COLORADO particularly sui table for the flexible operations necessary in the aftertreatment of prints.
Design advantages of the COLORADO
The cloth run is monitored, i. e. the loading of the individual sections is indicated and automatically con trolled.
There is an intensive interchange between treating liquor and fabric in every compartment. Each section is fitted with a pump and a heat exchanger.
The liquor flow from compartment to compartment by means of a clever piping system with fast-change couplings enables adapta tion to the respective stages of the process.
Before leaving the respective sections, effective squeezing of the fabric fakes place by means of a soft air-filled nip roller.
Each compartment has a separate heat exchanger and a separate temperature control. This enables individual temperature adjustment in each section (max. 30°C higher than in the neighbouring com partment).
The fabric transport is mechanical, so that regardless of varying liquor conditions and different fabric weights, a consistent fabric transport is maintained.
The loading of each individual com partment can be adapted to the process.
It is possible to carry out chemical treatment in stationary baths with metered bath additions.
Rinsing takes place in counterflow, so that the utilisation of the water is optimum, which means a reduc tion in the water consumption.
The water for the hot rinsing baths flows through the central counter-flow heat exchanger, so that the energy consumption is halved.
Pneumatically operated door over the entire machine width with large glass inspection windows.
Plastic slat liner quarantees smooth fabric transport.
Fig. 8.2. General view of the machine and in profile
Individual squeezing rollers filled with compressed air mould themselves to the fabric rope.
Adjustable sensors which monitor the required chamber loading and make any necessary corrections by automatic control.
Circulating pump for each compartment.
Heat exchanger with temperature control, for each compartment.
Reciprocating fabric transportation tube, for each compartment.
Infinite adjustment of bath level (adjustable overflow).
Valve with quick-fitting, interchangeable connections to enable bath drainage, liquor inflow, liquor metering or liquor flow from section to section.
Counterflow heat exchanger for pre-heating the fresh water and for cooling the effluent, with water meter at inflow.
Fabric feeding from the side.
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Fig. 8.3. General view of the machine
Table 8.1. Technical characteristics
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Type
B8
B10
B12
Dimension A
3040
3700
4360
Dimension В
4440
5100
5760
No. of compartments
8
10
12
Instal. electr. connected load in kW
22
27
32
Approx. power consumption in kW
14
17
20
Fabric capacity per compartment
50 kg
50 kg
50 kg
Liquor ratio with max. holding capacity
1:6
1:6
1:6
Max. temp. in °C
98
98
98
Machine speed in m/min.
10-75
10-75
10-75
Hourly output in kg (approx.)
when bleaching, scouring
300
350
400