Save water when dyeing with Fongs technology

17 Mar '10

11 min read

Goller Colora Dyeing Range

Recognizing this market demand, Fong's National has launched latest JUMBOFLOW series High Temperature Dyeing machines, which are the most economic hydraulic dyeing equipment ever developed for the industry. It is suitable for the processing of light to heavy weight fabrics with the lowest liquor ratio of 1: 4.5 to run the machine.

The JUMBOFLOW series machine is rigged with the Multi Saving Rinsing System (MSR), which allows the dyeing process to carry out cooling and rinsing simultaneously. For those dye houses without recycling of cooling water, MSR reuses the cooling water discharged from the heat exchanger directly and carries it back to the machine for the rinsing purpose. This avoids the direct discharge of the cooling water and hence reduces the water consumption considerably.

In order to rinse fabric effectively, the quantity of rinsing water and the rinsing time must be controlled, the AIR+ Advanced Intelligent Rinsing System is developed for this purpose to improve the rinsing efficiency. With the aid of flowmeter and modulation valve, the flow rate of filling water can be controlled automatically. During the rinsing process, the conductivity of the electrolytes in the dye liquor (in ppm) is actively monitored.

The rinsing process continues until it arrives at a particular TDS (total dissolved solids) value (standard before soaping: 2000ppm = 2g/L Na2SO4). As the usage of the alkaline is directly proportional to the TDS value, and the TDS value is also proportional to the usage of acetic acid, according to the Equivalent Weight Principle, it does not only guarantee the performance of neutralization by acetic acid, but also save water consumption and process time by approximately 40% and 33% respectively as compared of these with conventional dyeing machines.

(2) THEN-AIRFLOW® Dyeing Machine -
The researchers at THEN had already predicted the situation of increasing scarcity of usable water as far back as the 1970s, when they began developing a jet dyeing system that would dramatically save water. The basic idea was to use dye liquor for the sole purpose of dyeing the fabric, and not to waste copious amounts of it to simply move the fabric through the kier.

They achieved this by harnessing the air inside the dyeing vessel and use it as a jet stream to propel the fabric through the dyeing nozzle. Thus, the THEN-AIRFLOW® concept was born, and it became an immediate success initially in Europe and America in the 80s and 90s of the last century. Today, the global success story of the THEN-AIRFLOW® continues, and it has become the most popular brand of exhaust dyeing machines even in China.

As air is used to move the fabric through the machine, the liquor ratio required in THEN-AIRFLOW® machines is typically 30 to 50% lower than in hydraulic round vessel dyeing machines. For 100% cotton fabrics, it is typically 1:3.75 at full loading, and even at half loading, 1:4.6 is achievable, as the THEN-AIRFLOW machine works without a liquor bath in the bottom of the kier.