Traditional dyeing processes always need heat to fix colour into the fabric. With Cold Pad Batch (CPB) techniques, the dyeing liquor and fabrics are rolled at room temperature, therefore saving energy significantly. CPB was introduced for reactive dyes in 1957 with very simple technology: padding. Read more about List of Dyeing Machine for Fabric dye in Textile
Most new driers come with
built-in control equipment. Therefore this measure is especially attractive in
case existing drying equipment is replaced. The cost of instruments for measuring
the remaining moisture in dried fabrics ranges from USD
6 000 to 12 000. Savings are achieved through
the reduced energy consumption (up to 30%), less risk of excess drying (10 to
15% productivity increase) and an improvement of the quality of the final
product. Besides, in case the sales price of the fabric is based on the weight,
a higher moisture level will raise the sales value of the product (2 to 3%
increase).
Cold pad batch dyeing is a widespread technology for the semi-continuous dyeing of cellulose (mainly cotton and viscose) woven and knit fabric with reactive dyestuffs. The dyeing liquor and necessary auxiliary chemicals, like alkali for fixation, are fed to a dyeing trough for pad batch dyeing for impregnating the textile. The reactive dye, together with necessary alkali (Na2CO3 or NaSiO3) for fixation, is padded to cellulose fibres (cotton, viscose, lyocell, linen…) from a padder for impregnating. The impregnating fabric is maintained for 6-24 hours at room temperature (25-30oC) for meeting wet colourfastness. Then the fabric is rinsed out to clean the dyestuff on its surface.
This is one of the simplest methods and applied widely in Europe. This method is recommended due to : • Low energy consumption • Low investment in equipment and labour • Good quality in colour, its fastness and reproducibility • Reduction of pollution load As the liquor ratio is 1:6, there is a significant reduction in the amount of water and chemicals. Besides, this method does not require salts, as in other exhaust or pad-steam dyeing methods. It is estimated that 80% of BOD, COD can be reduced. CPB dyeing is a widespread technology for the semi-continuous dyeing of cellulose (mainly cotton or viscose) woven and knit fabric with reactive dyes.
Installation of soft starters and variable speed /frequency drives for higher capacity motors.The possibility of implementing this measure depends on the specifications of the final product and has to be analysed on a case by case basis. In general, thermal dewatering is expensive in comparison with other dewatering techniques, such as mechanical squeezing or vacuum extraction. In case a replacement of dewatering equipment between two baths is contemplated, it is therefore recommendable to consider switching techniques. In case thermal dewatering is selected, the air flow can be reduced to a point where a minimum airflow is guaranteed at all times in order to prevent condensation and contamination. It is very similar like Laboratory Jigger Dyeing Machine
Variable frequency drives (VFDs also termed as inverters) may also be useful in Jet / Soft flow dyeing machines, where most of the pumps are of higher capacity (than actual requirements) and water flow is throttled (around 50%). Hence it would be worthwhile to use VFDs (inverters) for the main pump and remove pressure control valve. (The savings could be around 30%.)
For the large size hydraulic jiggers the main pump motor consumes about 15 HP throughout the operation. The machine usually runs at 80 – 120 m/min against the designed speed of 150 m/min and in these cases it would be worthwhile to use an inverter by replacing flow control valve (savings in the range of 30%).
VFDs are also worthwhile to use for blowers in the stenters / dryers for efficient moisture removal. Increased power factor and reduced energy consumption and reduced GHG emission. Applicable for all motors of higher capacity and having variable speed applications (e.g. ID and FD fans of boilers, motors of drum washers etc.) This option is beneficial for only higher capacity motors. Savings: apart from the monetary savings, the reduction in the greenhouse gas emission is considerably high, which is a motivating factor for the implementation of this option. The payback of Jigger Machine for such a measure would be less than 20 months.
Airflow Dyeing Machine – Discontinuous processing of textile substrates requires more water and energy compared to continuous processes. However, for a long time efforts are undertaken to optimise discontinuous process with respect to productivity, efficiency and also to minimise energy and water consumption respectively. This lead to dyeing jets. Thereby liquor ratios have been reduced step by step. The latest developments have liquor ratio of 1:3 (for woven and PES fabric) and 1:4.5 (for woven CO fabric), instead of 1:10-1:12. Besides, the airflow dyeing machine offers combination of high productivity and reproductively and reduction of water, chemicals and energy consumption. It is similar to IR Dyeing Machine
To achieve such low liquor ratio, within the (jet) machine, the fabric is moved by moisturised air or a mixture of steam and air only (no liquid) along with a winch.
Rinsing is carried out in a continuous manner. During the whole rinsing process, the bottom valve is opened and rinsing water is discharged without additional contact with the fabric (which is the case in conventional machine). This also allows the discharge of hot bath liquors, also after high-temperature dyeing at 130oC. Thus, in addition to time saving, optimum heat recovery can be performed. The fabric itself is processed with low tension and crease formation is minimised. Due to lower liquor ratio, the new airflow-dyeing machine is expected to save up to 60% in water, and heating energy, 40% in chemicals, 35% in salts (and even 10% in dyestuffs). The application in this technique needs investment in new dyeing machine. Existing machine can not be retrofitted. The machine can be used for both knit and woven fabric and for nearly kinds of textile substrates.
Not applicable to fabrics consisting of wool or wool blends with a percentage of more than 50% wool because of felting. It is not recommended to dye linen fabric because of scaling of the machine with linen fluffs.
The system has been approved for silk, but it is still rarely applied in practice.
Investment cost for airflow dyeing machines, compared to conventional dyeing jets are around one third higher.
For one storage chamber, 150kg, it costs USD 190500.
Two storage chambers, 450kg, it costs USD 240000.
Three storage chambers, 625kg, it costs USD 309500.
Four storage chambers, 900kg, it costs USD 362000.
(Note Airflow Dyeing Machine : Please check the latest price from the market. It might vary depending on different tax and other charges in your country)
Polyester dyeing machine – The spent dye bath from polyester dyeing could be reused by adding make-up chemicals. The dye bath could be directly discharged into a storage tank kept at an elevated level (refer the enclosed picture), by the pressure of the machine itself and could be re-charged into the machine for the next batch by gravity. You can read Chemical Consumption for Dyeing Fabric Figure showing the arrangement of piping and valves for dye reuse dyeing machines in polyester dyeing This measure results in reduced water consumption, as well as reduced pollution load to the ETP (effluent treatment plant). In addition, reduced consumption of auxiliary chemicals in subsequent batches can also be achieved. Due to heat recovery, implementing this measure results in reduced energy consumption. Applicable in the polyester, as well as wool dyeing, where acid dyes of dark shades are used. Number of times of re-use depends on the level of oil content in the fabric and also on the type of shade. Savings of this option depends on the quantity of heat recovered and the reduction in quantity of auxiliary chemicals in subsequent dyeing operations, as well as the shade of dye used.
Substituting dyestuff for effective dyeing
Environmental problems surrounding the dyeing of fabrics can be reduced or even prevented in the materials procurement stage by means of a careful selection of chemicals, substitution of dyestuffs with more efficient ones and quality control of the raw materials.
Applying dyestuffs with a higher colour intensity (and, although with a lesser impact, with higher fixation rates) can reduce the amount of dyestuff disposed off through the wastewater considerably. Colour intense dyestuffs require less pigment to achieve the same colour intensity.
Reactive pigments contain one or more reactive groups, which increase the fixation rate of the dyestuff so less pigments are discharged with the wastewater. Reactive pigments can be used for dyeing materials such as cotton, polyamide and wool. Whenever possible, select reactive pigments with a stable fixation efficiency under variable process parameters such as liquor ratio, salt, pH level, temperature and time. Furthermore, selecting dyes with several reactive groups can result in a better fixation and resistance against hydrolysis. It is best to select pigments with a high colour intensity, combined with a high level of fixation and a low salt requirement. At the same time, the pigments should be easy to rinse out.
Substitution of pigments with a high metal content with pigments that are low in metals but with an equal or higher fixation level contributes to a reduction in the disposal of heavy metals into the wastewater. Apart from this, all other (auxiliary) materials necessary in the textile processing can also be screened as to their impact on the environment (e.g. formaldehyde, heavy metals, etc.). A reduction in the emissions of polluting substances into the wastewater and air. It is complicated to make such changes, and in the case of existing production processes with existing dyestuff recipes it is generally recommended not to make such changes. However, this measure is feasible in the case of new product designs or the optimization of existing production processes. Before implementing the substitution of chemicals, it is important to investigate the effects of the new materials on the quality of the end product and / or the production process. It is recommended to consult your materials supplier on this. The investments related to materials screening and switching depend on the additional costs of the materials involved. Savings are possible by consuming less raw materials and auxiliary materials and a reduction of the wastewater fees.
If sample is ok, then we need some garments to adjust the recipe
On next step we need some garments with shrinkage panels
Any adjustment is needed from sewing section before wash like attaching placket, attaching sleeve with body, reduce over stitching etc, then we will discuss with garments factory at sampling stage.
If buyers have any test requirements, then we should be informed during sampling. We have facility of wash test, rubbing test, pilling test in our in house lab.
Making blanket
To avoid different Sade in different lot of fabric, we wash the blanket, made of all lot of fabric
First we collect Three blankets of size 8X8” from garments factory
In the blanket need to mention the Roll no & yardage. Better use yellow marker pen.
We wash all three blankets as per standard.
Send two blankets for garments factory and kept one in our side.
We do trial test in washing by starting shade band. And we keep Enzyme/stone abrasion level standard. So that we can easily follow these created std in washing.
Shade grouping & all other related things we do in the washing plant. We will provide files to factory & merchandiser after completing the procedure.
Garments manufacturing company has to strictly followed this shade group when they cutting the fabrics.
DYEING PROCESS INDEX
PROGRAM NO
NAME OF PGM
NAME OF DYEING PROCES
01
Lt 60
Lt Shade (Dekol RSA)
02
Dk 60
Dk Shade(Dekol RSA)
03
Lt 70
Lt.Lemon yellow-RSA
04
Dk 70
Dk.Lemon yellow-RSA
05
Black
Black shade-RSA
06
Lt Tur
Lt Turq 80c-ASV
07
Dk Tur
Dk Turq 80c-ASV
08
Lt Rsp
Lt.R Special-60c-ASV
09
Dk Rsp
Dk.R Special-60c-ASV
10
Lt AVI
Avitera SE Light-60c
11
Dk AVI
Avitera SE Dark-60c
12
White
White 105c
13
Stripp
Stripping 110c
14
Toppin
Topping Af Fix & Soft
15
Stripe
Yn dyed Acid Wash
16
Stripe
Yn Dyed Deter Wash
17
Stripe
Yn Dyed Enzyme Wash
18
PB
PB(Rady to Dye)98c
19
PB
Pre Bleach-No Enzyme
20
Mc Cln
Machine Clean 110c
21
CVC/TC
CVC/TC(Only poly part)
22
Polyst
100% Polyster 130c
23
Lt Vis
100% Viscose Lt-RSA
24
Dk Vis
100% Viscose Dk-RSA
25
Lt V-T
Lt Turq-Viscose-ASV
26
Dk V-T
Dk Turq-Viscose-ASV
27
Blk B
Lt Black B,Salt-3por
28
Blk B
Dk Black B,Salt-3por
29
Dk Rsp
Dk Rspecial 60c–RSA
Dyeing Price Chart (Valid only for L/C):
The bellow price will be effective from the date Agreement made and will be applicable only for the days first party agreed hereby. Bellow is the price schedule. The mentioned bellow price will be only valid for cash transaction. If any verity works needed, additional charge will be made thereof.
Fabrication
Color
Tubular Finish
Open Finish
Remarks
100% Cotton Knitted Fabrics
Wash
40.00
50.00
If
lycra fabrics Tk. 20.00 will be added
White/Scouring
60.00
70.00
Light/Medium
100.00
110.00
Dark
105.00
115.00
Average
100.00
110.00
Black
125.00
135.00
Royal Blue
125.00
135.00
Other Processing charge per kg of fabric.
Sl
Others Process
Charge per kg(Tk)
1
Heat
setting
20.00
2
Sueding
18.00
3
Brushig
10.00
4
Dryer
(Tubler)
10.00
5
Stentering
(Drying)
18.00
6
Compacting
for Open
12.00
7
Compacting
for Tube
10.00
8
Slitting
03.00
9
Back
sewing
03.00
Note: All prices are including enzyme process. Without enzime process tk. 05.00 per kg. will be Less from the billing amount .
Terms & Conditions for Payment
Payment may be made in Cash, cheque or L/C.
For Cash or Cheque, payments to be maintained in considering bill.
Goods to be delivered on the basis of sufficient security reserve.
In L/C Payment, the L/C must be 90 days site & bank charge Tk.3.00 will be added.
For the agreement of L/C payment, the 1st party will start the works after opening the L/C and Fabric delivery will start after getting the bank acceptance.
Garment Dyeing Machine: Dollar conversion rate will be Tk 75.00
During the mercerisation process, cotton yarn or fabric (mainly woven fabric, but also knit fabric) is treated under tension in a solution of concentrated caustic soda (270 -300g NaOH per litre, 170-350 g NaOH per kg textile substrate, respectively) for about 40-50 seconds. Subsequently, the textile substrate is rinsed in order to remove caustic soda. This rinsing water is called weak lye (40-50 g NaOH /l) and can be concentrated by evaporation for recycling. In many cases, purification of the lye is required, which is normally carried out after evaporation. The purification technique depends on the extent of lye concentration and can be simple sedimentation and / or oxidation / flotation by injection of hydrogen peroxide. The concentration of weak lye is 5-8oBe (30-35 g NaOH/l) and is concentrated to 25-40oBe (225-485 g NaOH/l), depending on the mercerizing process applied. In case of raw mercerization (dry textile substrate is treated) the concentration is 25-28oBe and is 40oBe in case of non-raw mercerization. In case of raw mercerization, the concentration of impurities is significantly higher and thus also viscosity, which do not allow one to go for higher concentrations (circulation in evaporators is disturbed).
By recovery of caustic soda, alkaline burden of wastewater is reduced drastically and required acid for wastewater neutralisation is minimised.
Applicable for both to existing and new installations.
The more stages for evaporation, the more often the heat is reused and the lower is the steam consumption and herewith the running costs. Investment, however, obviously increases with more stages.
Investment costs mainly depend on plant size and purification technique and typically vary from EUR 200 000 to 800 000.
Evaporation requires approximately 0,3 kg steam / kg water evaporated in a 4-stage evaporation plant. This corresponds to 1,0 kg steam / kg recovered NaOH (28oBe) or 1,85 kg steam/ kg NaOH (40oBe). However, energy consumption for production of caustic soda by chloroakali electrolysis is also considerable.
Amortisation time depends on plant size and operation time per day. If mercerisation is permanently practised, pay back time is less than one year. In case, non-recovered caustic soda lye has to be neutralised with acid, the pay back time is less than six months, and caustic soda recovery may be very attractive.
The first caustic soda recovery plant went into operation more than one hundred years ago. Today, there are more than 300 plants in operation worldwide; especially for recovery of caustic soda from woven fabric mercerisation and yarn mercerisation and some from knit fabric mercerisation.
