UV Adhesive Curing
UV cure is an important surface technology for coatings, printing inks, computer disk production, adhesives and other applications, in industries characterized by fast production line speeds that apply very thin layers of materials on flat substrates.
The chances are that several times today you have touched an object "cured" using ultraviolet (UV) processing by simply reaching for your morning cereal box, handling a CD or DVD, reading a magazine, using your credit card, typing on your keyboard, driving your car, or just walking on your floor.
The advantages of UV have been well-documented -- particularly when used with manufactured products that include inks, adhesives and coatings on substrates that are sensitive to heat.
Advantages of UV Curing
Rapid Cure. Curing of UV ink or coating occurs in seconds, as opposed to the minutes or hours required by conventional solvent-based materials. This results in cleaner, sharper printing, and, importantly, gains in productivity.
Conservation of Energy. UV curing units have much lower energy requirements versus thermal production lines. Energy savings up to 80% are possible.
Space Saving. As UV curing units replace large heating ovens, very significant space savings are possible.
Environmentally and User Friendly. When cured, UV liquid coatings are converted to a solid so no solvent is discharged into the atmosphere. Compositions are typically solvent-free so emissions and flammability are not a concern. UV lamps can usually be installed on existing production lines.
Chemical Properties. Gloss, chemical and scuff resistance are far superior to the equivalent properties of conventional inks.
Mileage. UV ink has up to 3 times better mileage than solvent-based inks.
Flexibility Suited for Sensitive Substrates. Most systems do not contain any water or solvent. In addition, the process provides total control of the cure temperature making it ideal for application on heat sensitive substrates.
Complete Screen Stability. As UV ink only dries when exposed to a UV energy source, it will not dry in the mesh, provided all ambient UV light sources, such as sunlight and fluorescent shop lights, are filtered.
Fine Quality Print. Excellent dot quality allows four-colour process with prints up to 150 lines/inch.
Disadvantages of Traditional UV Curing
Lamp Replacement. Replacement of Lamps takes place every hundred hours or so. This can impart severe replacement costs and down-time considerations to a production line.
UV Safety. Attention to safety procedures and practices are greater with UV.
Thus, there are a large number of advantages for the use of UV curing methods compared with the more traditional thermal methods of curing that are leading to UV curing becoming the de-facto means of curing in modern industry.
The traditional means of generating UV light using lamps are the only major disadvantage to UV curing which is where curing systems based solid-state Multi-watt LED Light Engines have a large potential to replace these systems.
UV lamps are expensive, inefficient, generate large amounts of heat and are prone to reliability issues, as described above. They are also not efficient at small spot curing applications and can be difficult to transport or align into difficult application areas.
The use of solid-state Multi-watt LED Light Engine sources for these types of applications would bring together the advantages of UV curing stated above along with the clear cost, size, reliability and performance gains through the use of a Multi-watt LED Light Engine light source. Thus, all aspects of UV curing can be advantageous given a good appreciation for the safety aspects in UV light. Even the safety aspects can be improved due to the better control and directionality of UV light from Multi-watt LED Light Engines compared with lamps.
In particular, new environmental protection laws are driving manufacturers to adopt UV curing techniques. It is very timely for reliable and cost effective UV curing systems to be offered into the market place utilising the latest advances in solid-state UV Multi-watt LED Light Engine illumination devices.
The types of applications for UV curing cover the following categories:
- Coatings on: Compact Discs (CD/DVD), Hardwood Flooring, Shopping Bags, Optical Fibres, Furniture Laminates, Release Papers, Vacuum Metallised Plastic, Credit Cards, Beverage Cans, Photographic Film, Magazine Covers, Wall Panelling, Vinyl Floor Tile, Leather Finishes, Magnetic Media (tape & floppy disks), Galvanized Metal Tubing.
- Inks for: Lithographic, letterpress, flexographic, gravure and screen printing
- Adhesives for: Automotive headlamps, Pressure sensitive labels and decals, Potting and encapsulation of electronic components, Plastic components assembly for the medical industry.
- Printing Plates: Letterpress, flexographic and gravure.
- Miscellaneous: Dental fillings, Rapid prototyping resins
As can be seen the market use is very large and obviously growing.