A common turntable system design for semipermanent molding involves eight stations as seen in this model though installations are customizable to foundriesrsquo individual circumstances

Available Technology Can Optimize Aluminum Molding

Jan. 14, 2016
Automated systems can be designed, built to match foundries’ performance and productivity goals Aerospace and automotive Semi-permanent molding Turntables and conventional set-ups

Aerospace and automotive production continues to offer a strong level of demand for aluminum castings, creating highly competitive conditions for foundries supporting those markets. So, it is not surprising that aluminum foundries are looking at equipment options that will help them provide the best possible castings to their customers at the most attractive cost. 

To some of those foundries, it’s surprising that some manufacturing and equipment options, all proven effective and widely available, can be deployed to help those operations establish and maintain competitiveness in aluminum automotive and aerospace sectors. Here are some of the options foundries should consider to gain those competitive advantages.

Low-pressure semi-permanent molding — These are often fully automated production centers used to produce castings designed with the material integrity requirements of thin-walled castings. During the automatic sequence of operation, these completely enclosed machines are able to set cores automatically; extract castings; set gate screens; blow off the drag mold; and present the castings to the operator for inspection.

Some of the standard design features that promote high productivity include dual-cope ejection, for two cavity molds; up to 20 channels of cooling water/air; loose piece capabilities; heavy-duty, six-sided pulls for the drag mold; and manual tool locks to ease the tooling loading sequence.

Other features to look for that will promote high productivity include variable tooling capability, up to 55x64x34 in. (WxDxH); a holding furnace (e.g., 4,500-lb capacity) with automatic door for loading and unloading; safety pawls and ratchets to handle the main platen; and a preheat combustion system.

For low-pressure, semi-permanent molding, the typical mechanical dry cycle is designed to be 75 sec/cycle. For a typical solidification, depending on the customer’s tooling requirements, a casting-to-casting production time in the range of five minutes may be expected. To provide a complete turnkey system installation, ancillary systems (also readily available) would include core machines, gas generators, core conveyor handling systems, platforms, tooling loading systems, and mobile recharging furnaces.  

Turntable semi-permanent, vertically parted molding — Design changes to these system over several years have improved operations, reliability, and maintainability to meet current production requirements. Some manufacturers’ turntable systems use five casting benches arranged around an electric motor-driven turntable, with a diameter of about 26 ft. A system like this is designed with a minimum platform height of 39 in., so there is no need for a casting pit with such an installation.

Turn, Turn, Turn

Some of the standard design details of semi-permanent turntable molding systems are a 10-position table, with positive locator shot pin; five modular benches, accurately located and leveled; and tooling sizes up to 38.25x41.375x30.75 in. (WxDxH).

Functional details of these installations may include a modular bottom ejector, or angled ejectors; individual dual end pulls, or optional side pulls; a cope cover strip cylinder; and accessible tooling cylinder locks. The electric turntable drive system powers a five-piece construction, with a diameter of 26 ft., and a vertically actuated cylinder swing arm assembly. The system’s access plates are removable, and the water-cooling system is controllable. Lubrication is an automated function.

For such a system the typical mechanical dry cycle is 75 seconds/station. For a typical solidification, depending on a particular customer’s tooling package, a production rate of 48 castings per hour may be expected.

A complete, turnkey set-up of such a system would include ancillaries like a furnace; pouring/ladling gantry; machines for core setting, extraction, and degating/deburring; and conveyors for taking away finished molds.

Conventional, semi-permanent, vertically parted molding — Similar to an automotive turntable system, which is associated with cylinder head production, a turntable system for horizontally parted molding is simplified, and flexible enough to run a wide range of parts typical to most production foundries. The “tilt back after pouring motion” can be included with these machines, if desired.  Water-cooling and thermocouple controls can be include too, according to customer-specific requirements. 

These turntable systems are available in a common, eight-station model, customizable upon request. Although similar in design to an automotive series of turntable systems, the same effort in design capabilities, reliability, and maintainability have been incorporated. 

Among the standard design elements are the eight-position, electrically driven turntable with positive locator shot pin, and eight modular benches, accurately located and leveled. The turntable is a modular installation, with no need for casting pits.

The tooling size is up to 44x29.5x24.375 in. (WxDxH). The system has loose piece controls, and a centralized distribution for all utilities.

Central distribution union, with all utilities

The typical mechanical dry cycle time for an eight-station turntable of this type is 36 seconds per station. For a typical solidification, depending on a particular customer’s tooling package, a production rate of 96 castings per hour may be expected.

A complete, turnkey set-up of such a system would include ancillaries like a furnace; pouring/ladling gantry; machines for core setting, extraction, and degating/deburring; and conveyors for taking away finished molds.

The best way to evaluate all the available options is to work with the equipment designer from the start of any design project.  They will recommend the best equipment for your casting, to achieve your quality and production requirements.

Bill Vondriska is sales manager for EMI Inc. Visit www.emi-inc.com