Lab-Scale Softflow Dyeing Machine

Lab-Scale Softflow Dyeing Machine

Goods to be handled: Softflow Dyeing Machine – Woven and knit goods of various kind
Processing capacity: Weaight: Min. 1 Kg or above
Cloth Speed: Variable Speed Control
Liquir Volume: 10 – 60 Liters or higher
Max-working Temperature: 130 C or higher
Material of Machine: Stainless steel
Heating/ Cooling Heating at Below 0.5 to above 4 °C/min and cooling below 3 °C/min
Liquor preparation bath Min. 10 L
Liquor preparation bath Min. 10 L

Dye Spots-

Definition and Causes:

This common problem and defect can be caused by one or a combination of the following:

Undessolved dyes, especially if dye granules and powder instead of liquid dyes are used. Read about Woven Fabric Jigger Machine

Incorrect use of Defoamer chemicals. In certain dye procedures due to the machine’s high pressure and temperature, the interaction of some chemicals produces a large volume of foam which can inhibit the fabric’s rotation and movement. To remove this, de-foaming chemicals are used. Incomplete removal of these foams can sometimes cause a build-up of coagulated small particles on the fabric. 

Incorrect use of Carriers in Polyester dyeing. Generally Carrier type chemicals are used to facilitate the Disperse dye exhaustion in to the fibers. At certain low temperatures, due to the condensation, unwashed droplets of these chemicals can cause spots on the fabric. (Normally lighter than the ground color).

There are other causes that could create dye spots. The above mentioned are the most common in the industry.

Softflow Dyeing Machine Preventive Suggestions:

The use of correct procedures and chemically compatible dyes and chemicals is a critical part of the dyeing process.

Corrective Measures:

Depending on the type of fabric, in most cases, a high temperature scouring using 

Dispersing chemicals, Phosphoric acid, and soda ash will remove the spots.

Poor Crocking-

Definition and Causes:

The transfer of dyes from one fabric surface and causing the staining of another fabric surface through rubbing action is referred to as Crocking and is evaluated using a standard Grey Scale system.

This is often caused by the incomplete removal and cleaning of the left-over dyes from the fabric surface in the after-treatment process.

In the majority of dyeing processes, most of the dyes are either fully absorbed or exhausted by the fabric (with the exception of pigment dyeing). The left-over dyes need to be removed thoroughly.

Preventive Suggestions:

A complete after-treatment in the form of Reduction Clear (for Disperse dyes), Fixation (for Direct and Acid dyes), and Soaping (for Reactive dyes) must be given to minimize the staining problem.

Corrective Measures:

In most cases, repeating this after-treatment will improve the crocking properties of the fabric.

Poor Color Fastness-

Definition and Causes:

Generally, the ability of a dyed fabric to retain its color is referred to as Color Fastness.

This ability is normally measured in terms of fading due to exposure to washing, perspiration, light sources, etc.

Color Fastness properties of fabrics which are also evaluated by the Grey Scale system are adversely affected by the following:

Incomplete color fixing in direct dyeing process, reducing the wash fastness. 

Incomplete fabric soaping in Reactive dyeing, reducing the wash fastness.

The use of Alkali sensitive dyes, reducing the perspiration fastness.

The use of UV sensitive dyes or incorrect PH values, reducing light fastness.

The use of dyestuffs which have poor overall fastness properties.

There are other factors which can adversely affect dyed fabrics color fastness. The above mentioned are the most common causes.

Preventive Suggestions:

To ensure a higher level of color fastness is achieved, all technical aspects of dye and procedure selection must be examined and considered.

Corrective Measures – Softflow Dyeing Machine:

Based on the type of dyes used, the use of an appropriate rewash will improve the required fastness.