CO2 lasers advance
PROCESS PROVIDES HEALTH AND SAFETY
ADVANTAGES FOR WORK ENVIRONMENT
In the early days of industrial CO2 lasers, a fair amount of attention was focused on pursuing laser cutting abrasive (sandpaper) discs (FIGURE 1) as a viable market. The logic was clear, as a laser solution would eliminate the need for hard tooling. However, the economics were not favorable, as the capital cost of implementing laser technology was
just too high and the production rates were too slow when
compared to existing die-cutting solutions.
Additionally, those die-cutting processes were well established and there were no compelling reasons to pursue a laser
solution because die cutting did not present challenges that a
laser process would solve. In recent years, that has changed.
This article reviews the history of producing abrasive sanding
discs from well-established die-cutting practices to a laser
process required to meet new demands placed on abrasive
Abrasive disc production
Abrasive material is produced in 48-in.-wide or wider mas-
ter rolls, with the abrasive grit on one side of the roll substrate
and a means of attachment to the backup pad on the other.
The attachment methods are typically a pressure-sensitive
adhesive or, more commonly, a polymer ‘loop’ material that
will physically bond to the ‘hook’ surface of the backup pad
(think Velcro). While the material handling systems for die cutting and laser cutting are different, they all require the ability to
unroll the incoming material, process the material by performing a periphery through-cut and, if needed, produce dust-ex-
traction holes on the disc surface, singulating the disc from
the roll, removing the unused waste skeleton, and stacking
the discs into counted piles for insertion into boxes for pur-
chase by the end user.
Abrasive disc production has always been the domain of
flat-bed die cutting, and for good reason. Even though lasers
offered advantages, die cutting was (and in many cases
remains) the most cost-effective means of production, especially for discs that only require a periphery cut or a periphery
cut with large dust-extraction holes.
Flat-bed die systems use an upper platen that is attached
to a hydraulic ram. The steel rule die is secured to the platen
and once the hydraulic ram is actuated, the steel rule pene-
trates the abrasive material and the part is produced. These
systems are capable of production rates up to 60 strokes/min.
Additionally, if the die board is steel-ruled with three 6-in.-di-
ameter discs, it is possible to produce 180 discs/min, resulting in high production rates for a nominal investment. A steel-rule die also has a long life and low cost because the die only
costs a couple-hundred dollars and it self-sharpens while die
cutting the abrasive. With this background, it is easy to see
FIGURE 1. A laser-cut, multi-hole abrasive disc is attached
to a backup pad for use on a dual-action pneumatic sander.