Metal packaging production at top speed
For more than half a year, a Schuler impact extrusion press has been used at a new production line at M/s Alumatic Cans Private Limited.
With the help of the X-250S, the company located in Pune manufactures in between 180 and 200 aerosol cans per minute. The metal packaging press was delivered by Schuler including slug feeder and tools, the rest of the line by M/s PacksysGlobal Thailand.
“None of the production lines we have already operated before is as fast as the one with the X-250S at its centre”, said M/s Alumatic Cans’ managing director Danesh Sayani.
“Schuler has not only installed the press on site, but also ensured that it fits into the production process. The service experts are always available in case of any problems.”
The most important feature of Schuler’s XS series is the motion characteristic of the knuckle joint. This design provides a slide motion that permits higher production speeds. At the same time, it improves part quality and broadens the spectrum of possible parts that can be made on the press. Other performance enhancing design features complement the motion characteristics.
The XS series has four articulated joints in the design of its knuckle joint drive as compared to conventional impact extrusion presses with three. This creates slide motion characteristics that are especially favourable for both speed and part quality with very long nominal forming travel. The slower impact speed on the slugs provides protection for the punches and ensures longer tool lifetime.
Thanks to the longer nominal force stroke, more material can be formed and therefore thicker slugs. The forming stroke of the X250S is 20 mm, which is about three times that of conventional presses. Thus, the XS presses are much more flexible in their range of applications. Significantly larger and more complex parts can be produced on this series.
Compared to a conventional impact extrusion press, the forward motion of the slide on the XS press is faster. Towards front dead center it becomes slower than on a press with conventional drive. Thanks to the slower slide speed, the impact is softer than on a conventional press with the same stroke rate. After impact, the slide motion is more constant and guarantees very uniform speed forming. The slide return stroke of the XS starts earlier and has the same speed as a conventional press.
Very stiff wear free slide guiding guarantees utmost precision in slide movement. This is essential to assure the quality of the parts and provide long tool life, while achieving high production rates. Tool changeovers can be performed in a matter of a few minutes. The tool holders are self-centering by means of specially shaped receptacles, eliminating the need to adjust the die relative to the punch.
A precise indexing sequence is essential for production at high speeds. The systems gain flexibility and can be controlled independently due to the uncoupling of the slug feeding and finished part transfer functions. The NC servo drive controls the dial feed plate that provides both slug feed and part transfer. This way the slugs can be guided smoothly in front of the die without vibration.
The finished part removal function is driven by a second servo motor. Here too, the motion has been optimised. It consists of three phases: the part is picked up slowly, quickly transferred out of the punch area and gently deposited onto the exit conveyor.