A journey at the speed of light between deadly rays and rainbows
Every employee of this company has been the protagonist of a conversation about this kind:
“What does your company do?”
“We make colors.”
“In what sense?”
Silence. Panic.
A voice in the head that screams: “And now how do you explain how coloring substances and pigments work?”
Welcome. You are not alone. Let’s start from the beginning…
In order to illustrate what pigments are for, we first need to understand what color is. Some might call it a feeling, a mental elaboration, an artistic expression. My mentor, on the other hand, has always defined it as a physical phenomenon perceived by the brain through the eyes, sense organs. In fact, color as a physical characteristic of an object is determined by electromagnetic waves. These waves “compose” light. When a ray of light hits a surface, it absorbs some wavelengths and lets others “escape”, it is said to “reflect” them. Unabsorbed waves are bounced away, transmitting color. Each visible wavelength corresponds to a color.
Stars and Ghosts
There are electromagnetic waves everywhere. But are they harmless? Well, not really. Depends on. Fortunately, we have an atmosphere that defends us, more or less, from the most damaging cosmic rays coming from stars. Waves are characterized by intensity and frequency or wavelength, measured in nanometers (nm). This measure is inversely proportional to the frequency. Therefore, high frequencies correspond to low wavelengths and vice versa. Low-frequency radiations are, for example, infrared rays (those of microwaves) and radio waves (that’s right, those of the radio); high-frequency radiation is ultraviolet (the one that makes us tan), X-rays (the radiologist’s rays) and gamma rays (the deadly ones, coming from the radioactive decay of stellar atomic nuclei). Between these two groups we have radiations ranging from 380 nm to 720 nm, known as visible light. Our ability to see is due precisely to the radiation of this range of waves, called the visible spectrum (no, we are not talking about ghosts).
Coloring pigments in darkness
Visible light radiation comes from a source, called a light source, and there are various types of light source. The point is that each source is only able to transmit certain radiations and, consequently, certain colors. The most famous and complete light source in the range of waves to offer can be found by raising our eyes to the sky. That’s right, it’s the Sun, which constantly sends us electromagnetic waves of visible light (and also UV rays and gamma rays, but don’t pay attention to it). Other sources can be electric bulbs, but these are only able to radiate certain wavelengths. This explains why we can’t distinguish colors well at night. For example, in the dark of the evening, a blue car in a parking lot illuminated only by a street lamp receives only waves of the length of yellow and red and not purple or blue. Not being able to reflect what it does not receive, it will appear to our eyes as if it had a black body.
Color or coloring?
And finally we can go back to what a company that uses coloring substances and pigments in its products (for plastic, for example) deals with: coloring and color are two similar things, but not the same. As we have read, if color has mostly to do with wave physics, coloring is a matter of chemistry. In fact, each material has its own color, characterized by a spectrophotometric curve (again, we are not talking about ghosts!). This curve indicates the percentage of light energy reflected for each wavelength received. In practice, it allows you to “read” how many and which colors are absorbed and which reflections. For example, a piece of plastic containing red iron oxide will reflect a high percentage of red waves and absorb blue and green waves. This means that the coloring substance is the chemical compound present on a surface that interacts most with light.
It’s not magic, it’s science!
So we can finally answer the initial question without panicking: what do we do? Those who produce colors, such as inks, varnishes or masterbatches have the task of formulating mixes of coloring substances and pigments. These, processed and joined in the right way, are able to disperse or cover the surface of the final product, allowing it to interact with light radiation in the best possible way. We are a bit like alchemists: we study the elements of nature, we know their composition and their reactions in exposure to electromagnetic waves; we do chemistry and physics experiments; We learn to read the light of stars and electrical sources. Our dream is to enrich ourselves with knowledge and to give the world wonderfully colored objects.
What are masterbatches, plastics, and other questions
Still doubts? Write to us, we are here to answer your curiosity!
