Finding the right leveling agent is often a tedious process, considering all the parameters. It is important to check dosage and product variations to figure out the correct chemistry and fine tune the formulation. Make the selection of your leveling agents easy for your coating formulation by getting answers to most of your questions that arise during the selection process. Learn the role of solvents and other important factors in leveling and, thus, come up with the best coating product.
Dyeing auxiliaries are defined as chemicals or formulated chemicals which enables a processing operation in dyeing to be carried out more effectively. Dyeing auxiliary includes dye fixing agents, cationizing agent, dispersing & leveling agents etc. They help in stabilizing the dyeing bath to improve the exhaustion, achieve level dyeing and improve fastness properties.
Need for Leveling Agents
It is admitted for many paints that a perfect appearance means also a perfect leveling. Poor leveling (like orange peel or ghosting) may not influence significantly the paint parameters in time, as it is more aesthetic orientated. But the leveling agent itself may cause some severe issues.
A correct leveling agent helps in reaching the wanted leveling and final film finish. But a wrong choice may lead to surface defects such as craters, pinholes, loss of gloss or even inter-coat adhesion problems. Therefore, to understand the leveling, it is important to understand the influence of the surface tension on the paint and finding a balance is critical:
Too low surface tension may be good for the substrate wetting but may lead also to a wavy surface.
Too high surface tension can cause adhesion and surface wetting issues.
If you are exploring the factors that govern leveling in any formulation, it might be worth to begin with an in-depth understanding of leveling basics (surface tension, contact angle, test method, etc.) at first.
Which leveling agent is suitable for your formulation?
There are several base chemistries to choose from when selecting a leveling agent & lower the surface tension to the point just that you need for a desired application.
The most common types of leveling agents are listed below.
Silicone-based agents (Polydimethylsiloxane modified - PDMS)
Acrylate-based agents (Polyacrylate)
Fluorocarbon-based agents (Modified Fluorocarbons)
Hydrocarbon-based leveling agents: less efficient than previous families
Understand each chemistry in detail and see which one fits best for your formulation & end-application needs.
Silicone oils are important tools in vitreoretinal surgery and their introduction has represented a pivotal moment in the management of ophthalmic surgery as they are equipped with a combination of chemical and physical properties that have propelled their surgical use. Silicone oils are essentially used as intraocular tamponade thanks to their ability to maintain the adhesion between retina and retinal pigment epithelium (RPE).
The safe and effective use of tamponade substances means the knowledge of their physical and chemical properties because it is on the basis of this knowledge that surgeons have to decide what type of tamponade they should use.