artimelt UV hotmelt adhesives based on acrylates are irradiated with UVC light which triggers the crosslinking reaction. The C-range is the shortest wavelength in the ultraviolet spectrum which means the resulting adhesives are resistant to sunlight (UVA and UVB). Commercially available medium-pressure mercury UV lamps, such as those commonly used in the printing industry, are used for crosslinking.
Influencing factors
UV-curable hotmelt adhesives give processors new options. Different adhesion properties can be achieved by varying the degree of crosslinking in the adhesive. This affects the adhesion and shear resistance properties: High internal strength (cohesion) is achieved by strong crosslinking the adhesive, while high adhesion values (adhesion) are achieved by reducing the UV radiation.
Application areas
As a pioneer in this field, artimelt launched the first UV hotmelts for self-adhesive labels in the 1990s. Since then, artimelt has developed hotmelts for a wide range of applications, such as permanent or removable and repositionable labels and adhesive tapes, as well as adhesives for direct contact with skin, such as for wound plasters, adhesive bandages, and dressings.
Advantages
- No drying necessary
- Breathable
- Adhesive is ready to use
- Environmentally friendly – can replace solvent-based systems
- Coating weights up to 125 g/m2
- High transparency
- When fully crosslinked, temperature resistant up to 320°F (160°C) – even up to 392°F (200°C) briefly
- Resistant to plasticizers and chemicals
- UV-resistant – suitable for outdoor applications
- Chemically bonded photoinitiator – no migration
- Components FDA-approved for direct or indirect contact with food