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INTRODUCTION
There is a widespread perception that paper. products printed with
radiation cured inks and coatings cannot be recycled as compared to conventionally
cured (thermal) systems. From the raw material suppliers to the scrap paper brokers,
the Consensus is that landfill or incineration are the only way to deal with such
waste. There are, of course, a few exceptions, and we are aware of a couple of mills
that presently recycle and deink radiation cured paper waste. There are also
recycling mills that currently utilize EB coated scrap and may not be aware of it.
The studies presented here are from mill trials where EB printed and coated foodboard
waste was incorporated into the standard furnish. The purpose was to document any
effects on product quality or any process changes necessitated by the inclusion of
EB waste. Although the results of these trials are encouraging, it is recognized
that this type of waste may not be suitable for all recycling operations. However,
it clearly demonstrated that EB coated paper waste can be effectively recycled with
no diminution of board quality.
The precursor to all this work was the success of a simple Waring
blender test, whereby electron beam coated-waste was able to be dispersed equally
as well as standard clay coated board. When samples of this stock were subsequently viewed on a blue glass display, it was determined that mills with adequate pulping
and cleaning equipment should be able to handle it. It is important to note that
at-the cylinder mill where our first mill scale study was done, the EB paper waste
was typically hid between outer layers of unprinted waste. This was the same
procedure as for thermally cured printed waste. Therefore, even though all finely
dispersed ink and coating particles were not completely removed through cleaners and
screens, the final product exhibited no evidence of any ink or coating particles.
A subsequent trial which comprised our second study was done at a Fourdrinier mill
producing a single layer sheet. The finely dispersed ink particles were deemed
acceptable in the finished product by the mill manager. A third trial investigated the feasibility
of deinking the EB coated waste. This pilot trial demonstrated that EB coatings
can be succeeefully dispersed and floated using a conventional pulperand flotation aid. As previously touched upon, these three studies are only the first step in evaluating the recyclability of EB coated waste.
