Plasma Gluing May End Need For Varnish Cut Outs
By Lisa Cross -- Graphic Arts Online, May 1, 2008
The Bobst Group entered an agreement with German manufacturer Plasmatreat GmbH to be the exclusive representative for Openair atmospheric plasma technology products for applications in the packaging folding and gluing area.
“Plasma” is a state of matter, like gas, liquids and solids, but with higher energy; the sun is made up of plasma. In printing, plasma is present in metal halide and xenon flash lamps. Plasmatreat pioneered the use of atmospheric plasma to modify material surfaces to increase their functionality; the company holds 50 patents in the area.
The Openair technology enhances bonding on difficult-to-glue synthetic materials such as plastics and varnished, laminated or metallized paperboard packaging. It also avoids the need for varnish cutouts on glue flaps—eliminating use of special varnish plates–and milling, which slows production and generates waste and dust.
Bobst says plastic carton or box applications that use Polyurethane (PUR) adhesives will benefit greatly from the technology, as the process removes any organic residue, dust and moisture from the glue flaps, raises the surface tension of the substrate and creates a surface that will readily accept adhesives. Openair also eliminates undesirable air bubbles in the glue line of transparent packaging, while leaving no traces of the treatment on the product surface, the company claims.
The process uses a concentrated beam of ions and free electrons to clean and activate a substrate without burning or damaging surfaces. It delivers a low-voltage, low-heat surface treatment solution to the hard-to-bond materials, and doesn't generate ozone or other harmful fumes or vapors, says the company.
The system is said to be easy to install and operate, and can be placed inline on virtually any folder-gluer from any manufacturer.
The Openair system also offers greater efficiency and application control, resulting in reduced waste and adhesive consumption and increased production speeds on most jobs, says Bobst.
