ITMA review in terms of knitted cotton fabric dyeing and knitting

Any new investment on the capital machine there is always 2 considerations:

1. The investor thinks about the cost-effectiveness, ROI and user-friendliness
2. Quality consistency and operational flexibility.

Once both the requirements from investor and operation end are matched the investment would be the safe one. In terms of Bangladesh, the textile sector investment would be feasible if any investment ROI is more than 30% per annum.

In the processing industry, water and steam cost is increasing day by day. The water cost is involved in different stages. In the factories, raw water mostly withdrawn from underground by a submersible pump (electricity involves) then treated by WTP (chemical cost involves).

During dyeing the basic chemical is used in proportion of volume of water (more water need more chemicals); after dyeing, the water again need to be treated in ETP (investment is huge for big size ETP also chemical cost is required during operation) to comply the environment (more water effluent treated per kg fabric cost increases). The steam cost is directly involved with boiler gas bill (the more water needs more steam to be heated).

So finally, the reduction of water consumption is the major goal for the sustainable concept for machine manufacturer and chemical manufacture.

Due to the initial investment cost; more floor space and lack of skilled manpower the CPB and CO2 dyeing yet not popular in Bangladesh market. In the ITMA 2019 several companies showed their latest technology in terms of business sustainability. Here I will discuss 3 major technologies from 3 different companies.

ACME

Advantage

1. Per kg, cotton fabric dyeing require 25 liters water
2. Multifunction rinsing, shower rinsing, lots rinsing and double overflow rinsing
3. Dyeing process controlled by no. of cycles of fabric circulate instead of time
4. Liquor totally separated from fabrics. Achieves smooth running and free of tangling

Limitation

1. Initial price seems too high
2. The conveyor belt maintenance may create a problem (If require)

Nano dye

This is mainly process of pretreatment including canonized the cotton to dye the fabric without electrolyte (salt).

Total process is recommended by NANO-Dye (The USA company). Benninger made them open width pretreatment machine; TubeTex made tubular pretreatment machine for Nano Dye.

A ‘drop-in’ sustainable dye solution that changes the current method of dyeing cotton or cotton blended textiles.

Nano-Dye’s process changes the charge of the cotton molecule to the opposite charge of the dye, after then let’s all the work in a regular process.

Advantage

1. Total salt-free dyeing.
2. Dye pick up will be more than 98 % which will be added benefit for the ETP considering zero discharge
3. Pretreatment unit can be used the existing exhaust dyeing floor and the present dyeing capacity may increase 20% to 30%
4. Total dyeing cost will save for any medium to dark color
5. Energy savings of Nano-Dye are remarkable at over 90%. Solid waste in the effluent is reduced by over 95%, and water savings are over 60%

Limitation

1. The Pretreatment cost will be around 25 cents/Kg fabric (Included 5 type of chemical) which have to use only from nano dye source.
2. There is 8 to 10 hours dwell time after pretreatment. The wet fabric unloading and loading also make some problem in the floor
3. The shade re-matching or topping will be difficult

SAVER

This looks like a regular exhaust dyeing machine. But they improve the insider kier water system; heating system and dosing system. It claims 1 Kg cotton fabric can be dye just 20 liters of water.

The dye kier is heated by a newly developed patented coil system, located at the bottom of the fabric loading chamber. Bottom coil obtaining less pump power requirement, high nozzle pressure and heating gradient by removing the resistance impact on the outlet line of the pump without heat loss.

Compare to the other machine price is reasonable for this machine and maybe more convenient. If practically it can prove 1 kg cotton fabric can dye with 20 liters water then it can be a good machine.

Besides the machine other equipment like wastewater heat recovery; economizer; hot air reuse; stenter exhaust heat recovery; also available in the exhibition which can reduce the gas consumption of the existing factory.

Some chemicals for energy-saving option (like Dr. Petry. NDA. FTR) were also available in the exhibition which can be reduced the consumption of existing boiler steam.

Circular knitting

The circular weft knitting replacing other technology day by day; like carpet knitting machine replacing carpet loom; terry knitting machine replacing terry towel loom; sweater and shoe upper fabric now can easily make in a circular knitting machine.

In the exhibition, new improvement is displayed like Mayer showed upper fabric m/c Scuba in their jacquard; Pailung showed High-Speed Open width; Fukuhara showed Temperature control system High-Speed m/c considering the tropical country.

Here we discussed in details about the knitting from Roving instead of Yarn (Innovate by Terrot) in terms of sustainability. Mayer & Cie also have this technology.

Corizon by Terrot: Terrot created a technology that combines the knowledge of spinning and knitting in one revolutionary process. With Corizon®, generate a core yarn by combining a core filament that is surrounded by parallel fibers.

Individual fibers are wound around the outside like a corkscrew. This structure generates sufficient strength and reliability to transport the yarn from the Corizon® system to any circular knitting machine.

Advantages

1. Combination of two process steps (spinning and knitting) in one • short lead-time • more less warehousing • savings in energy, space and material costs
2. This is fully integrated fluff blow-off at spinning devices and core yarn feeding exact synchronization with a circular knitting machine
3. “Corizon” enables manufacturers and their designers to create new kinds of knitting qualities in terms of softness, tightness, haptic, getting more brilliance and less fabric twist
4. With “Corizon” knitters are able to change the yarn count during the knitting process. In this way, they can save a lot of product development time.