Why Lubricants?
Dyebath lubrication has become an important topic over last two decades and many products have been introduced in the market to avoid running creases. Running creases are a quality aspect and it is classified under dyeing failures. It is not possible at all times to predict running creases and or produce them on purpose.
Running creases are optical, surface related flaws which are created in the discontinuous dyeing in rope form. The origin lies in the altered density of yarns, loops and weaves due to shear and compression forces in the yarn and fibre array and in the altered surface aspect of fibres due to fibre-to-fibre and fibre-to-metal abrasion in the dyeing equipment.
Cause of Running creases:
The phenomenon exists for delicate fabrics in winch and beck and further worsened in jet equipment now so popular. These reasons could be low liquor ratio, very high fabric speeds and high heating and cooling rates, fabric transport in the machines apart from abrasion and compressive and shear forces in the fabric.
The increased problem of running creases in jets can be explained on the example of compression and filling stages in a tube. Here the main aspects are the filling amount, the fabric properties and the pleating stage of the rope. Of minor importance is the width increment due to lengthwise compression. Thus, follows that, if the fabric is ductile and easily pliable the orientation of the rope in the swelling zone is accidental and follows statistical rules. The bending is always at the same places which minimises the opening of the fabric structures. Also, the transport through the intensive or acceleration stage is random, not in an orderly way, which eliminates the repeated abrasion in one specific area.
The dyebath lubricants increase the ductility of the rope, enables fibre to fibre movement, reduces compression and shear forces in both woven and knitted fabric, abrasion conditions in the jet dyeing equipment. The lubricity of the rope is not exclusively an aspect of the fabric surface and its friction values, but also related to the ductility and the pleating of the rope. However, the reduction of the surface friction of the fabric as part of the effectivity of a dyebath lubricant will reduce the damage caused by abrasion and defibrillation.
Compatibility of dyebath lubricants with other components of dyeing becomes a critical factor when lubricants are used in the dyebath. The properties of the ideal dyebath lubricant have been summarised as:
Excellent fibre-to-fibre and fibre-to-metal lubrication
Economical
No effect on other physical properties such as handle, water repellency and absorbency
Foam suppressant or deaerating agent
No effect on reproducibility of dyeing
No effect on fastness properties
Non-yellowing
Easily washed out
Biodegradable
In case of dyebath lubricants, particular attention must be paid to the type of substrate (hydrophilic or hydrophobic) and to substantivity of the lubricant for that substrate. Another important consideration is ionicity of the lubricant in relation to the components of the dyebath, since this has such an important bearing on compatibility (clearly, anionic lubricants should be avoided when basic dyes are used). Solubility and/or dispersibility in relation to dyebath composition and the conditions of dyeing (temperature, pH, and liquor ratio) are also important, since the overall hydrophobic/hydrophilic balance has a major influence on compatibility. The behaviour of lubricant during dyeing can be just as critical as during dyeing. Many lubricants promote undesirable thermo-migration of disperse dyes on polyester during high temperature drying and heat setting, leading to lower wet fastness.
Natural products such as animal fats and vegetable oils still constitute an important share of the lubricants market although synthetic types are gaining acceptance. Natural fats and oils include saponified fatty acids, fatty esters, fatty alcohols and fatty amides. Various anionic groups are suitable, including carboxylate, phosphate, phosphonate, sulphate or sulphonate, the last named being the most widely preferred. Esterification of the fatty acids is particularly useful. For example, ethoxylation with ethylene oxide enables products of subtly graded character to be produced, depending on the degree of hydrophobicity of the fatty acid and the degree of ethoxylation. Sulphonates offer greater stability at higher pH and ionic strength but they can generate troublesome foaming.
Synthetic based lubricants include polyacrylates, acrylamide/acrylic acid copolymers, emulsified paraffin oils and waxes, modified silicones. The acrylates generally combine excellent solubility in the dyebath with fabric lubrication and such polymers can be designed to cover a wide range of solubility, risibility and lubricating performance. Ionicity can be varied, whilst acrylic esters offer scope for incorporating other functionalities along the polymer chain. Acrylic esters also allow the degree of anionicity to be varied. Acrylamide groups generally result in increased stability, especially in acidic media where the amido groups are partially protonated and thus mildly cationic, whilst in neutral media they behave substantially as non-ionic moieties.
Dyebath Lubricants offered by Nestor Industries :
It is a high molecular weight polymeric based lubricant used for reducing cracks and crease marks in wet processing. It reduces the friction between both fiber to fiber and fiber to metal friction.
It is a high-performance preparation and lubricant to prevent rope mark, creasing in cellulosics and for jet processing of polyester.
Nestor Industries’ team provides personalized advice on lubricating agents based on your specific requirements. We stay abreast of industry trends and continually explore cutting-edge lubricating agents. Nestor Industries prioritizes sustainable practices for a greener future.
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
