Technical advances pay a "green" bonus
From: DIE CASTING WORLD - VOL 15 No. 1 Page. 31
Although efficiency and reliability are the first considerations for any die-caster investing in capital equipment, increasingly stringent legislation is moving the issue of environment impact up the agenda.
Considerations of tomorrow as well as today are also affecting the development programmers of equipment manufacturers, builder Oskar Frech & Co demonstrate.
At the most general level, improvements that at motivated in the first instance by reasons of profitability can also have positive environmental implications. Lower power consumption, for example, will reduce the die caster's variable cost; but it also contributes to the global task of reducing the rate at which finite resources are depleted.
As well as the die casting machine itself, this principle applies to every action of every item of powered equipment that helps to turn hot metal into a die cast part. These include furnace, metal ladle, die heater/cooler, die spray, casting removal unit, cooling conveyor, and so on.
In this connection it is worth noting the "green" credentials of the Real-time Control system. This gives the die caster much control over the way in which the metal enters and flows through the die so that the spur can be shorter, runners fewer and flash negligible. All of this amounts to less metal and metal re-melted, with obvious environment benefits.
Improvements to the layout of the machine also have a "green" dimension, as Frech ahs demonstrated with its new F and M Series of hot and cold chamber machines, both of which have a completely re-thought hydraulic system. Amongst many other features, the pipe work of the injection unit is now integrated into the base of the machine, which reduces the risk of leakage and thereby the need for disposal where it can do no harm.
Amongst ancillary equipment, automated die spraying is today an almost obligatory part of a machine specification. Frech's latest system, the Spraymotion 2, moves in two axes in order to stay close to the profile of the cavity. Optional (but desirable) extras include modular nozzles that can be assembled in almost any configuration, and the "Vapojet" spray head that prevents loss of fluid at the end of the spray cycle.
This is a threefold instance of getting the most from the least, and doing the least environmental damage while you are about it. One of the most serious environmental threats comes from SF6, the gas commonly used to blanket the dosing furnace for magnesium die-casting that is also known to damage the ozone layer. Frech has already reduced significantly the volume of SF6 it uses, and as a further step is also investigating the feasibility of using "ozone friendly" hydrofluocarbon 134 instead, which research commissioned by the International Magnesium Association has shown to have very similar handling characteristics.
All electric machines
The clearest example of Frech's ability to minimize the use of materials that are potentially polluting or in increasingly short supply is the all electric E Series, the nearest thing yet to a sustainable hot chamber die-casting machine. Now sufficiently well established to be more than a technical curiosity, the E Series has replaced complex hydraulics with brushless servo-motors for all the movements of the machine: die locking/opening, casting ejection, injection and spraying.
Not content with being "cleaner" when compared with fluid dependent hydraulics, it also uses considerably less of the electric power on which it depends. This is another example of doing more for less.
To put numbers on that surprising claim, a 24 hour head to head test of a hydraulic DAW 80 RC machine and its electric equivalent running identical dies saw the E machine consuming 76.2 rather than 217.7kWh - saving of 65%. That looks good on the electricity bill, and just as good on the broader balance sheet that weighs up the odds for the planet's future.