Today we turn to the home stretch of ultraviolet products. In our last publication, we defined what ultraviolet varnish was, we talked about UV radiation and the different lamps that exist to carry out this product and process, briefly explaining the different types of drying that are done in these lamps and ending with the photoinitiators (necessary elements to understand what an ultraviolet varnish is).

Now, let’s take a closer look at the types of products with UV curing.

Types of UV curing

We can classify them into the following major groups:

Products containing volatile solvents (VOC).
2. Products without solvent content or at least minimal (no VOC). They can be further classified into:
2.1 Based on Polyester resin with styrene.
2.2 Based on Acrylic resins with acrylic monomers.

With solvent

All those in which the solvent participates in the formulation as the application vehicle. Robots, manual spray guns or curtain sprayers carry out the most common applications. They are normally used in an open pore, semi-porous systems, although closed pore is possible. There are formulations for both base and topcoats, either clear or pigmented.

In addition to everything seen so far, we also find another large group that we will deal with apart from those exposed above. It is the so-called DUAL CURE system:

This system is used to solve some problems with ultraviolet curing such as high drying due to excess weight and in pigmented products or due to little or no drying in shaded areas such as edges, corners, and so-called “sparrow’s beaks”. There are two types of these products:

1. Redox drying: (accelerant and peroxide) to which a photoinitiator is added to dry on the surface and allow the parts to be handled. After stacking, the redox reaction continues.
2. With Isocyanate: Normally formulated with hydroxylated resin to which isocyanate is added before application. This reaction takes place after UV curing.

Solvent-free

There are two types of solvent-free products, which are given to cover specific needs in each case, as follows:

1. Water-based: These are those in which water becomes part of the formulation, either by addition or the resin itself. They are most commonly used in Robot systems (guns). For pre-drying (before curing in lamps) laminar air tunnels with temperature, air percussion, MOS (microwave system), and Infrared lamps will be necessary. The application lines will consist of one or a combination of these elements.
2. 100% solids: These are those that have no organic solvent in their formulation. These are applied in rollers, curtain coating machines, vacuums, and other new systems.

Mixed

There are other products which, although not really 100% solid, have a very low VOC content, such as those intended for the application of mouldings, frames and baseboards. Its application is normally carried out by robots. Since this is a very wide market area, we will now detail its main characteristics:

• Are-airing times in pre-drying are very short 1-2 minutes.
• These highly reactive products can dry at high speeds (40-60 m/min).
• They are usually irritant products, but not toxic, so the use of protective equipment (goggles, gloves ….) is recommended.

UV Markets

We have made a “review” of a product that has many applications. We find transparent or pigmented products,  and best of all: in Industrias Químicas Iris we are willing to keep innovating, creating a customized product that is exactly what you need. Let’s take a look at some applications of the ultraviolet product.

Industrias Químicas Iris in full development offers a multitude of references, an infinity of finishes and resistances for countless markets. This is what makes us who we are.

For any questions or for more information, please feel free to email us at: industrias@quimicasiris.com.