The techniques for 'the inerting of ali electron beam processor have developed quite
slowly over the past two decades. The requirement of an environment of low oxygen
concentration in which to initiate and complete the addition polymerization process
efficiently has been a severe impediment to the industrial use of the technology.
Due to the absence of good, quantitative determinations of the "environmental"
requirements of the process, a great deal of misunderstanding has-resulted in what
the machine design should be providing for successful application of the equipment
in surface "curing" where the °2 inhibition of free radical initiated polymerization
can cause difficulty. Only' recently have publications begun to provide this data,
and progress is finally being made in providing integrated shielding:inerting product
handling designs which are optimized for industrial use.
This paper presents a continuation of studies presented at an earlier RadTech
conference, in which we presented the use of-degree of cure assays, employing soxhlet
extraction/gas ) analysis to optimize-the inerting performance of
an electron processor for (graphics) curing. The present work explores the use of:
combinations of pure (cryogenically produced)'nitrogen and lower purity (noncryogenically
produced) nitrogen, in order to reduce the cost of
operation of a, high speed, processor. This work has shown that a significant
percentage of the inerting gas can be replaced with lower purity N2, at a significant.
savings in cost. For the system(s) tested, the results have indicated that total
replacement of the high purity LN2 produced gas is not practicable.