Modern paint production: “As quickly and as much as possible with as little effort as possible”

In your opinion, what are the most important changes in paint production in recent years?

Frank Kother: If we compare the paint production of today with that of 20 years ago, I would mention the development of pigment concentrates and the associated new production processes. For example, mixing processes for semi-finished products that can replace the classic batch process. Here we find inline dispersion processes and large-volume mixing processes.

And how will this development continue in the future?

Kother: The goal is to establish continuous processes. No one has yet reached this, but some people are already thinking in this direction. The aim is to get away from the large mixing containers. So when we talk about things such as pilot-jet mixing technology or large-volume technology, we have to consider how the material can be mixed in the smallest possible premixing vessels so that as much as possible is produced as quickly and as much as possible with as little effort as possible. For me, the path to this is primarily determined by quality control, which is increasingly shifting into the pre-production area.

Frank Kother is Managing Director at TMC Technology & Marketing Consulting. He will open the EC Technology Forum | Optimizing cost and processes in paint formulation with a short course on 15 October in Berlin.

I find it difficult to completely say goodbye to the batch process in practice.

Kother: I can imagine that. So far, nobody has thought completely in this direction. Let’s take the production of a simple white lacquer as an example. Here we essentially have a binder and a white pigment dispersion as the basis. Nobody can really explain why it shouldn’t be possible to mix them in a static mixer in such a way that a good coating comes out. Of course, this requires proper quality control and sensible dosage and working procedures. But that’s the direction you should go.

Is this rather something for the big manufacturers with the corresponding volumes or can the niche manufacturers also implement it?

Kother: That’s also possible for smaller companies. Let’s take a solvent-based coating. It is made from ninety percent by volume standard binder, a few additives and a good 10 percent solvent. For this, the manufacturer needs an Ex system and special cleaning processes. If one now imagines that this is done using a small dosing unit that doses everything shortly before final filling, then the entire cleaning effort would be eliminated.

You mentioned that quality control should be carried out further ahead in the process. Can you explain this in more detail?

Kother: The first step I can take is to check semi-finished products before the paint production starts. There are enough standardised test options here. For example, solids share measurements of the binder or colour measurements are well defined. If we move all this forward, then we will already make a good step towards continuous production. We have been producing in a continuous process for one of my clients for a year now.

If you think in terms of in-line measurement and automation, you always have to deal with large amounts of data.

Kother: That is a necessary development because the process data must be evaluated, for example to determine deviations and to understand where changes come from. So far, the whole thing has been more like looking in the rear-view mirror. At the moment, you can usually only see the data of the end products. I haven’t yet seen many plants where something like this is already being consistently implemented. 

From your perspective, what does the use of semi-finished products mean for the actual coating formulation?

Kother: How to use these semi-finished products varies from coating manufacturer to coating manufacturer and depends on the portfolio. You have to see where the lowest common denominator is and how you can break that down. Be it mixed semi-finished products or individually pigmented semi-finished products or semi-finished rheological products.

If, for example, we look at the decoration sector, we can adjust many desired qualities with calcium carbonate and titanium dioxide mixtures. The aim is to produce as many different products as possible with as few raw materials as possible. This is of course easiest in the uncoloured, white range. However, this also works when colours come into play. Here, highly filled pigment concentrates with suitable mixing concepts can be used.

Is there enough choice of semi-finished products on the market?

Kother: There are already a few companies that offer many different products. The question is not whether you can buy them, but which ones you need and how to use them in the factory. For example, you have to consider the logistical costs. Calcium carbonate, for example, probably makes no sense as a semi-finished product. It costs around 200 EUR per ton, if there are added water and logistics costs, it will be too expensive. But I can already see that with the non-ferrous semi-finished products, there are already the first pigment premixes.

To what extent do the views into the future play a role in such projects?

When I start to set up such a project, I always ask the client how much do you want to produce in three years? Then the topic of forecasting comes into play. Many companies just take the data from the current year and then add 5% on top. Of course, that’s not enough, you have to see exactly which product I have today, and which one will run well in three years. On this basis the decision for the right semi-finished products can be made.

In addition, acceptance within the company is still an issue. The development departments then also have to formulate with semi-finished products. For example, I have a customer who has 13 different types of titanium dioxide in his house and my wish is to reduce that to one. To achive this you have to overcome some resistance.

But aren’t they all looking for ways to make formulations less complex?

Kother: Yes, they are. And of course, there are big differences, for example when it comes to titanium dioxide for automotive coatings or printing inks. You can’t just replace it. But when we talk about an application, it should be possible. But people have their habits and you have to get them on board.

The Interview was conducted by Jan Gesthuizen

Event tip

If you want to learn more about this technology and other ways to improve paint formulation and manufacturing, you should attend the European Coating Technology Forum | Optimising cost and processes in paint formulation in October 2019 in Berlin.