Nothing has as much influence over productivity as speed, but speed can be the enemy of quality. That's not necessarily true in handling molten metal, but the contrast of speed with quality is a constant concern. And because it is molten metal, safety is another serious consideration.

Bühler Druckguss AG, the Swiss diecasting machine builder, heads straight into this contrast with its new SpeeDiall process, a diecasting technology that was introduced last summer. Bühler (www.buhlergroup. com) indicates that its novel process cuts diecasting cycle times by up to 15%.

The company approached the new development with productivity in mind, knowing that diecasters always have a need for increasing their process efficiencies. Buhler explains that it analyzed existing conventional diecasting approaches in search of ways to reduce cycle times. Several control optimization processes emerged as a result, and one of these process solutions has now been patented.

It is the SpeeDiall process, an acronym drawn from a tagline: "speed increased alloy diecasting." The process is composed of a diecasting machine with a shut-off mechanism (slide) on the fixed die half, which makes it possible for early melt feed while the slide remains open. This shifts the melt feed from a primary process time to a secondary process time, so that the total casting cycle time is reduced to at least the length of the melt feed time.

Bühler says that SpeeDiall can be retrofitted "with relative ease" to its existing diecasting machines equipped with Dataspeed- and Datanet-generation control systems. The machine upgrade will include a software update and installation of an additional hydraulic accumulator, and of a core pull unit on the fixed-die mounting platen. (The new core pull unit is unnecessary if one is already in place.)

At the die end, a slide also will be installed on the fixed die half as a means of shutting off the shot sleeve while the die is open. (Bühler says customers may use their own engineers to carry out the die conversion, as preferred.)

Bühler says the effects of a SpeeDiall upgrade will be seen immediately. The machine control system calculates the optimal moment for melt-feed release, and can be mastered in just a few casting cycles, after which the machine can be switched to "synchronous mode" in order to begin meeting the reduced cycle time. The developer says that the process has already been successfully implemented at a number of diecasting operations, where cycle times have been reduced 12-15%.

To competed globally, foundries have to get the best performance from their production machinery. Bühler's SpeeDiall process focuses on machine utilization rates, cycle times, and scrap rates in order to cut per-unit production cost.

(Source from: Foundry Management & Technology)