Introduction:
Textile processing involves various stages, including dyeing, printing, and finishing, which require the use of chemicals and water. One common issue that arises during these processes is foam formation, which can lead to defects, reduced quality, and increased production time. This is where silicone defoamer comes into play, providing a solution to this persistent problem.
Silicone defoamer is a valuable additive in textile processing, offering numerous benefits that enhance the efficiency, quality, and sustainability of textile production. By controlling foam and improving processing conditions, silicone defoamer plays a crucial role in ensuring high-quality textiles that meet industry standards.
What is Foam?
Foam can be described as a stable dispersion of gas bubbles in a liquid medium. In pure liquids, foam is not stable. Foam is only stable in systems containing surfactants - like substances such as wetting agents, or certain surface control additives needed to improve important properties of the textile being processed.
Foam originates at various stages of production, such as pumping, stirring, dispersing and also the application of a liquid auxiliaries, through the entrapment of air bubbles. The air-liquid interface of these bubbles is surrounded by the surface-active materials in the system. Due to the bubbles’ low density, they rise to the surface. As the bubbles rise, smaller bubbles can combine to form larger bubbles which rise faster. At the surface, the bubbles accumulate and foam a layer. The air cannot escape because a lamella is formed which is stabilized by the presence of surfactants.
We can make a difference between macro-foam and micro-foam. Macro-foam is foam what appears at the surface of your system. Micro-foam is entreated foam into your system what can't rise fast enough to the surface to be destroyed. For both different defoamers are required. When having micro-foam there is a high need for air release agents who can coagulate micro bubble to bigger bubbles so the rise faster to the surface.
This is described by the Stokes law which says the speed of the air bubble is related to the diameter of your air bubble divided by the viscosity of your system.
In simple words: The bigger the air bubble the faster it will rise to the surface.
What is DEFOAMER?
Defoamer is a type of chemical additive used to control and eliminate foam in textile processing. It is a surface-active agent that reduces the surface tension of water, preventing foam from forming and stabilizing existing foam, allowing it to collapse more easily.
Defoaming Mechanism:
The presence of ionic surfactant molecules at the surface creates electrostatic repulsion. The bubbles come closer together as a result of the gravitational forces allowing the liquid to flow out of the foam and the lamella to become thinner and thinner.
The principle of inhibiting or destroying foam (defoaming) is generally based on an overcoming of the stabilizing mechanisms. Foam control additives (DEFOAMER) possess properties which are opposite to those needed for foam stabilisation.
Foam control additives function by a variety of mechanisms to prevent or rupture foam. The insolubility of a DEFOAMER is important for the movement of the DEFOAMER to the lamella. It needs to have a positive Entering coefficient. Creates low surface tension, so that they can be uniformly spread out on the surface. It needs to have a positive spreading coefficient. Ability to penetrate into the foam lamella to destabilize the foam to burst.
CHOOSING A FOAM CONTROL ADDITIVE
● Mineral oil：As opposed to solvent-based systems, the spreading of mineral oils in water-based systems is sufficient to act as a foam control additive. In the presence of hydrophobic particles, the mineral oil acts in addition as carrier for these particles, like hydrophobic silica or metallic soaps. The use of aromatic mineral oil, aliphatic mineral oil is preferred.
● Silicone： Both dimethylpolysiloxanes and modified polysiloxanes can be used as foam control agents in water-based systems. An important point to consider is the incorporation of the foam control additive in the system. Since they are not soluble in the system, a good distribution of the active substance is necessary. This can be controlled by the mixing speed and time, otherwise craters can be formed or loss of defoaming efficiency is observed.
Benefits in Textile Processing:
Defoamer offers several benefits in textile processing:
- * Improved dyeing and printing: Foam can interfere with the even distribution of dyes and printing agents, leading to uneven colour and poor print quality. Silicone defoamer ensures a smooth, foam-free process.
- * Increased productivity: By reducing foam, silicone defoamer saves time and increases production efficiency, as machines and equipment are less likely to clog or require frequent cleaning.
- * Enhanced fabric quality: Foam can leave residue on fabrics, affecting their texture and appearance. Silicone defoamer helps maintain fabric quality and prevents defects.
- * Environmental benefits: Silicone defoamer is biodegradable and non-toxic, making it an environmentally friendly option for textile processing.
How to Use Defoamer:
Defoamer can be added to the processing water or applied directly to the fabric. The recommended dosage varies depending on the specific process and fabric type.
For textile processing Nestor Industries Pvt Ltd. Manufactures a specialised defoamer which look after all the problems and gives the perfect remedies.
(Silicone Based Defoaming Agent)
Nestogen - JFD is highly dispersible and stable in hard water. It’s stable and performs at high temperature and high pressure and will not degrade under high shear conditions found in textile jet dye applications.
Properties:
Chemical nature : Polysiloxen condensate
Appearance : Milky white liquid
pH of 1% aq. Soln : 5.5-7.4
Solubility : easily dispersed in cold water.
Application :
Nestogen - JFD is added separately to the side tank of a jet-dyeing machine without further dilution at a level of 0.1 to 2 grams per liter (100-2000 ppm), depending on the foam characteristics of the bath.
Exact concentrations and performance can be determined by conducting standard laboratory foam tests with a sample of the foaming medium.
If any further information required on above you can get in touch with the technical representative of the company or write on below email id,
+91 8306083020 | +91 9377781836
