When optimising from a stock sheet at the end of a batch and the area of the stock
sheet is at least 10% larger than the area of the remaining order sizes to be optimised,
then the theoretical results from any optimiser should be the same for that last
stock sheet. The only difference comes in the way that the off cuts are fragmented
throughout the optimisation diagram. What Trimloss does in such circumstances therefore,
is to switch to optimising the off cuts, so that as much as the off cut area can
be forced into one large off cut wherever possible, thus making it more likely to
be re-usable. This off cut maximisation feature is just one more utilisation of
mathematical decision theory in Trimloss.
When putting an unused third split of a full stock sheet back into stock, or when
putting an off cut smaller than this back into stock, extreme care should be taken
when the glass is any type of Low E. As soon as a Low E glass coated surface is
exposed to the air, its quality starts deteriorating rapidly. It does this even
quicker in cold and damp weather conditions. The precise rate of deterioration varies
with the individual Low E glass types, but as a general rule, we recommend that if
you want to maintain high product quality, then any exposed Low E stock left over
at the end of the day should be discarded. This is not a problem with Trimloss,
because these off-cuts are kept to an absolute minimum. Other optimisation software
may however, not be so diligent in minimising the area of such off-cuts returned
to stock, especially if their off-cut management is limited only to those spanning
the full height of the original stock sheet and wasting any smaller off-cuts.
In a batch requiring say 5 stock sheets of 4mm clear glass and there is need to use
only 90% of the last sheet, then the last 10% of that sheet can mostly be saved using
this Trimloss feature. This represents a 2% saving on the whole run from this feature
alone. For other batches with different amounts of ordered glass to be cut from
the last stock sheet, the savings from this feature can be even greater.
Moorcroft Computer Services do not know of any other optimiser which has this feature.
What has been observed however, is that there are some optimisers which can be told
to produce different versions of the last cutting diagram, leaving it to the computer
operator to choose the one with the least area of unusable off-cuts. This feature
therefore will produce different results from different operators, none of which
is going to be anywhere near as good as the results from Trimloss using this off
cut maximisation feature.