Plastic joint part, used in wooden panels, was detailed with another construction rib due to
expanding deformation of groove used for tight anchoring. With help of simulation tools,
we have proven, that design change managed to reduce unwanted expanding for about 50%
in the middle section and also positively affected narrowing at the ends of the groove.
Construction rib effectively ensures tight fit. Following part of thesis researched options
for injection moulding process optimization. Ideally we want to achieve short cycles with
perfect output. We suspect, that shortening of moulding cycle will reduce manufacturing
cost. We expect to cover costs of design change. For that manner, we designed experiment
with help of Taguchi’s methods. Experiment was designed to test the output change for
three factors. Mould temperature, backing pressure time and cooling time. During the
experiment we monitored process outputs like surface aesthetics, mass and dimensional
stability. Within borders of experimental settings, it was proved, that higher mould
temperature positively affects surface aesthetics. Mass and Dimension of product did not
change. Moulding process was proved robust within experimental settings. With that in
mind we managed to shorten existing moulding cycle time of 20 seconds for 2 seconds.
Calculation showed, that with shortening of moulding cycle managed for 2 seconds cost
dropped below the one, calculated before investment in design change. For average 3 shift
work, we can save about 1168€ per million pieces. Considering fact, that process was
proven to be robust, we can think about additional cycle shortening in near future with
same methods.
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