How Does Chemical Etching Work?

These days, there are plenty of etching processes to choose from. However, chemical etching is one of the oldest techniques that have been developed. In fact, decorating a medieval armor usually makes use of chemical etching. Nowadays, chemical etching has improved tremendously. With new methods and chemical solutions, results are more elaborate and accurate.

So, how does chemical etching work? In this article, you’ll learn more about this specific subject.

Chemical Etching Explained

There are different techniques for chemical etching. Having said that, most methods would generally include:

* Cleaning

* Laminating

* Exposing

* Developing

* Etching

* Stripping

Generally, the process starts with a light-sensitive laminated layer that’s introduced to the material that you want to etch. The material that you wish to etch is also known as the substrate.

The substrate and light-sensitive laminated layer are then exposed to an ultraviolet light together with the negative. The ultraviolet light will then “harden” this light-sensitive layer. However, because of the negative, there will be areas of the light-sensitive layer that can be washed away as it didn’t “harden” during the UV light exposure. The washing away of the laminated layer is also known as the Development step.

The next step is to introduce an etching chemical. Keep in mind that there are parts of the material that is protected by a light-sensitive laminated material. Thus, the etching solution will only eat through the parts that are unprotected.

After the etching process is done, the next step is to strip off the remaining hardened light-sensitive laminated layer. At this point, the etching process is mostly done.

Why Chemical Etching?

Chemical etching is an excellent choice if you want to create high-precision, multi-layer, and complex metal parts. The tolerance of the etching process is usually +/- 10%. For example, when you chemically etch a specific part that’s 100 μm, you can expect a deviation of up to 10 μm. Also, chemical etching is highly advisable if you want something with profiled edges, sharp edges, and round holes.

Another desirable feature of chemical etching is its flexibility in terms of scalability. You can start creating a prototype from drawings in just a matter of days at a relatively affordable cost. Also, converting to large-scale production is rapid and affordable as it does not require expensive equipment found in other etching methods.

What Materials Can Be Etched

Chemical etching can be used for a wide variety of materials. The method especially shines for metals. This is because almost all types of metals can be etched chemically.

For the most part, you can use chemical etching for:

* Steels

* Aluminum

* Nickel Alloys

* Copper

* Brass

Wrapping It All Up

Chemical etching is a process of using an etching solution to turn your drawing into a real-life prototype. The substrate is coated with a light-sensitive laminated layer and together with the negative, it is then exposed to UV light. The laminated layer will serve as a protection against the etching solution.

When the etching solution is applied, it will start eating through the substrate except for the laminated parts. The last step of the etching process is stripping away the remaining laminated part.

Etching will always have a place despite the many newer methods as its cost-efficient, flexible, and accurate.