One among the very leading manufacturers of green sand molding equipment world-wide, FRITZ HANSBERG of Modena, Italy, has recently completed the supply of one high-performance molding line for the GEORG FISCHER foundry in Singen, Germany, dedicated to the production of nodular iron safety castings, including suspension arms for various major automotive companies.

The facility has been ordered in October 2000, after extensive bench-mark tests had confirmed the superior quality of the molds produced on existing HANSBERG molding machines operating in two foundries located in Spain (FUNOSA) and Austria (+GF+ Herzogenburg).

The line has been commissioned at the beginning of September 2001. Three-shift production has started in November 2001, with a planned output of 110 ton/day.

Top quality molds are obtained thanks to HANSBERG's unique molding system

As is it is known, HANSBERG's mold making technology centers on a three-phase molding sequence featuring pre-fill, shoot, and squeeze. The pre-fill phase ensures the uniform distribution of mechanically prepared, lump-free sand over the whole pattern surface.

Shooting then provides excellent mold surface hardness up to the flask walls, while the final squeeze phase provides the desired compaction throughout the depth of the mold. Usage of sand is strictly controlled and no pattern plate venting is required.

Stripping Loading Pre-filling	Shooting	Squeezing

A single molding machine producing at a rate of more than 200 molds/h

Rated at 200 plus molds/h with internal flask dimensions of 790 x 1,050 x 230/230 mm and 60 min cooling time, the new HANSBERG green sand molding line for the GEORG FISCHER foundry in Singen stands out as one of the most productive facilities in the industry.

The facility has an extremely compact, linear layout, a typical feature of HANSBERG molding lines of the newest generation. This allows for reduced shop-floor occupation and foundation requirements.
Both cope and drag molds are produced by a single pre-fill/shoot/squeeze, vertical-loop molding machine. In this type of molding machine, the cope and drag pattern plate bolsters travel in sequence first through the pre-fill station, where they mate with the corresponding flask and are partially filled with facing sand, then through the shoot/squeeze/strip station, where the actual mold is made and stripped from the pattern.

Outstanding performances

Lower operating costs derive from design innovation and state-of-the-art actuator control technologies.

Most hydraulic cylinders feature closed-loop proportional valve control with feedback on the actuator position. This allows for smooth, repetitive movements and absolute cycle time control.

Electrically driven units displacing heavy loads over relatively long distances in extremely limited times are driven by brush-less motors and controlled through axis control systems. This is the case with the cooling strand end transfer units.

Double-step indexing of the pouring line allows to extend pouring time without affecting the molding rate.

Previous to flask parting, the cooled mold is ejected from the flask in the upward direction, pushed sideways and presented to an automatic hooking unit that hooks and holds the casting by its running system while the mold itself falls onto a shakeout grid where it is destroyed.

Another interesting feature of the facility is automatic core setting. Aimed at relieving the operators from a repetitive, scrap-generating job, automatic core setting is carried-out by means of gripper units that pick-off the cores from off-line templates and release them into the mold cavities.

Pattern plate bolster change-over is carried-out within cycle time by means of a three-station turntable.