Desiccants 101: What Are They?

When you work with plastics, there is always a chance that resin will absorb moisture that is present in the environment. While some resins may only allow moisture to accumulate on the surface, many others absorb moisture. If moisture isn’t removed from these plastics, it can react with polymers and cause the structure of plastics to change. This reaction is hydrolysis, and it can lead to reduced strength as well as other issues with the items produced.

silica gel desiccant regeneration

To remove moisture, a desiccant dryer may be used. Before getting into what this process is, let’s discuss what a desiccant is and how it maintains dryness in resins.

The Definition of a Desiccant

A desiccant is a substance that dries items and keeps them dry. They’re chemically stable, making them a popular choice for various industrial operations. Silica gel desiccants are a common way to dry materials, but other desiccants include calcium sulfate, charcoal, molecular sieves, and calcium chloride.

How Does Drying with Desiccants Work?

There are many different kinds of desiccant dryers, but the process is similar for each one. Air is enclosed in a space and circulates in the dryer, removing moisture. Desiccants will often be in the form of small beads, which are put into containers by the thousands. When air passes through the desiccant, moisture is absorbed, and the moisture content of air is reduced.

Over time, the moisture content in the beads will get too high and desiccants will need to be regenerated. When silica gel desiccant regeneration occurs, the moisture in the desiccant is released using heat. The desiccant is then cooled and can be reused.

Now that you know a bit more about desiccants, you can work with plastics more efficiently and avoid moisture that can cause issues during production of your materials and items.