𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞 : 𝐏𝐈𝐆𝐌𝐄𝐍𝐓 𝐃𝐈𝐒𝐏𝐄𝐑𝐒𝐈𝐎𝐍 𝐈𝐍 𝐂𝐎𝐀𝐓𝐈𝐍𝐆𝐒 𝐏𝐀𝐑𝐓 𝟏 — 𝐓𝐇𝐄 𝐏𝐑𝐎𝐂𝐄𝐒𝐒

 𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞

𝐏𝐈𝐆𝐌𝐄𝐍𝐓 𝐃𝐈𝐒𝐏𝐄𝐑𝐒𝐈𝐎𝐍 𝐈𝐍 𝐂𝐎𝐀𝐓𝐈𝐍𝐆𝐒

𝐏𝐀𝐑𝐓 𝟏 — 𝐓𝐇𝐄 𝐏𝐑𝐎𝐂𝐄𝐒𝐒

A technical series exploring the science, chemistry and formulation principles behind effective pigment dispersion.

Have you ever reformulated a coating because of poor color development, low gloss or unexpected viscosity...

...only to discover that the formulation itself wasn't necessarily the problem?

Sometimes, the answer is hidden earlier in the process:

Pigment dispersion.

Pigment dispersion is more than simply mixing pigment into a liquid.

It is a controlled process in which pigment particles must be properly incorporated, separated and maintained in a stable state.

And this process can be understood through three fundamental stages:

1️⃣ 𝐖𝐄𝐓𝐓𝐈𝐍𝐆

The liquid phase must establish effective contact with the pigment surface.

This allows the pigment to become properly incorporated into the vehicle and prepares it for the next stage.

The objective:

Create effective contact between liquid and pigment.

2️⃣ 𝐃𝐄𝐀𝐆𝐆𝐋𝐎𝐌𝐄𝐑𝐀𝐓𝐈𝐎𝐍

Mechanical energy is applied to break down pigment agglomerates and separate the pigment structures.

But the objective is not simply to "grind harder."

It is to achieve the required degree of particle separation efficiently, without unnecessarily increasing energy, temperature or processing time.

The objective:

Separate pigment structures efficiently.

3️⃣𝐒𝐓𝐀𝐁𝐈𝐋𝐈𝐙𝐀𝐓𝐈𝐎𝐍

Once the pigment has been dispersed, the separated particles must remain in a controlled state.

The formulation must preserve the dispersion state achieved during processing.

The objective:

Maintain the dispersion state over time.

WHY DOES THE SEQUENCE MATTER?

These stages are not independent.

Each one prepares the system for the next:

Poor wetting → inefficient deagglomeration

Incomplete deagglomeration → limited dispersion

Poor stabilization → loss of the dispersion state

This is why pigment dispersion cannot be reduced to a single variable such as:

mixing speed, milling time or grind gauge.

A successful dispersion is the result of:

CHEMISTRY + MECHANICAL ENERGY + PROCESS CONTROL

Throughout my experience working with coatings, I have found that some formulation problems are not necessarily caused by a "bad" raw material.

Sometimes, we simply haven't allowed the raw materials to perform at their full potential.

And that is what makes pigment dispersion so interesting.

The goal is not simply to disperse a pigment.

The goal is to control what happens to the pigment throughout the entire process.

source : Ernesto Muñiz Mata