April 9, 2020
Industrial colorants are not one size fits all when it comes to use in industrial coatings. Instead, they can be complex and the chemistries varied. And they have to be because the end application can be varied. The end application should drive the colorant choice based on factors like quality, cost and chemistry. In fact, these traits are critical when it comes to choosing the right colorant system for the coating.
Choosing a colorant system can be a process with inherent risk. Using a colorant that does not match the application of the coating can diminish the quality of the final product. Also, using a colorant with a value that is not aligned to the value of the coating could yield unexpected results.
For example, suppose you’re producing a 2K urethane coating. The coating consists of two components that are combined before application. During the cure process of these two components, there’s a reaction between the urethane and curative that makes the final coating more durable.
If you use a non-functional colorant system, the resin or additive package in the colorants will not react within the final film and could reduce the durability of the coating. By selecting the wrong colorant for the coating, you may have added something to the coating that can reduce the quality of your high-performance coating. This is contradictory to the reason why that high-performance coating was formulated.
In contrast, if you add a colorant system with the right characteristics, you’ll produce a high-quality coating that performs the way it was designed.
To produce an industrial coating that maintains desired properties when tinted, you’ll need the right colorants for the job. Here are the factors to keep in mind when choosing a colorant system.
As mentioned above, industrial coatings can have many applications. Coatings for general use, automotive, flooring and other protective applications are formulated differently, and have unique needs in order to succeed.
To create an effective coating, you’ll need a colorant with traits that match the objective of the application.
For example, coatings that are used to provide a visual reference, such as color-coded bolts, are used to identify and not necessarily protect. Field coatings are only designed for short-term use. Because these types of coatings generally do not have a long life span and low cost, you would use a low-cost colorant to meet the requirement of affordability.
Protective coatings serve primarily to protect the items they coat, with potentially lower aesthetic requirements. To fulfill this function, a protective coating would need a colorant that aligns with the protective properties of the base.
Automotive coatings are used to protect and provide an aesthetic value. Automotive coatings need a colorant that does not detract from the protective properties of the coating and provides colors that are extremely durable and lightfast.
Finding the right colorant for an application is an art of balancing all the factors that will dictate its success.
Before selecting a colorant, it’s important to consider if you need the colorant system to tint multiple coatings, or just one or two.
Some colorants are more universal in nature and can tint multiple types of coatings. Other colorants are formulated for specialized compatibility in a limited number of coating types. Both types of colorants have their benefits and tradeoffs.
Universal colorants can be used in many different coatings and are expected to perform well in all of them. You can think of these systems as being “good for many”. Having a universal colorant system is extremely important if tinting is done at the point of sale. Also, they are important if you have many different coatings to tint and don’t have the capability to use a different colorant system for each coating.
Universality is a great concept when tinting more coatings with the same colorant system is required. However, you are giving up some level of performance in each system. To achieve a universal chemistry, compromises must inevitably be made to ensure acceptable performance in each coating. So, a certain level of durability might be given up when tinting with a universal colorant system. But that might be perfectly suitable for the end application.
In contrast to universality, specialized systems include a colorant system chemistry that is designed for a limited number of coating types. You can think of these systems as being “great for few”. By using a colorant system specialized for a specific coating type, the colorant system will complement the coating performance, creating a high-performing final product. The specialized colorants tend to deliver better coating performance, which makes it suitable for medium to heavy duty applications.
The method of tinting will also have a significant influence over the colorants you can use. The two primary methods, point-of-sale (POS) and in-plant, may require different tinting strengths, chemistries and rheology. Manufacturers will design each colorant for one or both of these tinting methods.
A POS colorant needs to be suitable for gravimetric or volumetric dispensing. To pump colorants into a can of paint, the colorants have to have the ideal rheological properties so that colorants flow into the canister properly. Colorants with poor rheological properties won’t dispense properly and you’ll end up with multiple mis-tints.
Rheological properties go beyond just dispensing. POS colorants also need to have a rheology that provides in-canister stability, as low volume colors could sit in the dispenser for a considerable amount of time.
Lastly, this is where universality becomes very important. In a POS setting, you’ll need single colorant system that will be able to tint every coating you sell.
If you’re going to use a colorant system for in-plant tinting, the system should have good stability, since you may be opening and closing colorant containers multiple times. The colorants may also have a higher pigment loading to help to ensure optimal performance and more efficient tinting capabilities. Finally, you may have different a colorant system for every coating.
Unlike POS, tight tint strength specifications aren’t as important for in-plant. But, while it’s not a must-have, tighter specifications can help limit the number of batch corrections. So, comparing in-plant colorants on their tint specifications is important as tighter specifications can save time in production.
Finally, you have the potential for wider viscosity ranges when tinting in a plant. This gives formulators more flexibility to use the best colorant for the coating. All combined, there are more options to ensure peak coating performance when using an in-plant tinting method with a colorant system well-suited for the coating.
Another crucial factor to consider is the alignment between the value of the colorant system and the value of the coating.
Colorants, just like coatings, can vary in price, quality and value. The quality you get out of a colorant should match the quality you’re delivering with your coating.
Does the cost of the colorant system match the benefits received? Do you get what you paid for and what you need?
Asking these questions is critical to developing a cost-effective and high performing coating.
Take, for example, a polysiloxane-based colorant system. Systems with this chemistry provide a ton of value to the coating’s performance. Their silicone-based makeup provides great durability for coatings. But, it also makes them more expensive.
Getting a polysiloxane-based colorant system at a low-cost colorant system price would be fantastic. However, the cost of the components isn’t the same, so the price you pay for them can’t be the same. Using a low-cost colorant system in this instance will reduce the real and perceived value of the coating due to the reduction in performance properties such as durability and color float.
Sometimes, it may work the other way. Using a high-quality, and more costly, colorant system in a field coating would be dramatically out of line with the value of the coating. The coating does not need long-term performance. So, there is no sense using a high-quality colorant here. It would drive up costs without providing a meaningful impact.
To determine the value of a colorant system, it must be a cross-functional decision. In other words, procurement can’t be the sole decision-maker of what colorant system to use. A cross-functional decision between sales, technical, marketing, production and procurement should be employed. Only with input from multiple stakeholders would the optimal colorant system to use for each industrial coating be determined.
While not a trait of the colorant, supplier support can be an added value to the colorant system. The colorant supplier can help determine what colorant systems have traits that match the coating’s requirements. General technical service can provide customers with information about how to use the supplier’s colorants and where they can be used.
Great customer support makes it easier to sort through and select colorants based on the traits listed above. These suppliers generally have multiple options to help you find the right colorant for your coating. They ensure that you have the right system in place while saving you time and guesswork. They provide a critical role in identifying the most valuable colorant for a coating.
If you’re a formulator tinting multiple different types of coatings or only have one coating to tint, be mindful of how these traits affect your final coatings and the colorants systems you have on hand. The success of an industrial coating relies on finding the right colorant for the job.