Automated Material Handling and Delivery to the Mold. Powder can be fed directly into the mold using a variety of systems that enable control and tracking of material use.

Direct Mold Temperature Monitoring. Direct control measurements can be made via slip-rings. This enables cycles to be established based on actual material or mold temperature rather than environment temperatures and times.

Automatic Venting. The action of the vent can be controlled automatically to coincide with the end of powder transfer to the mold surface. This prevents powder escape while allowing the air inside the mold to expand and contract.

	Ejector Pins. Parts can be pushed from the mold using ejector pins built directly into the mold and controlled by the machine to simplify part removal.
	Drop Box Delivery Systems (without insulation). Without a hot environment, the use of drop boxes on the mold is simplified and their physical size reduced without the need for insulation. Multiple layers can be included in a part for barrier and/or strength properties.
	Pressure Devices. Using pressure inside the mold can aid in part quality, surface finish and faster cycle times. Air flow through the inside of the mold may also reduce cycle times.

Accurate Mold Opening and Closing. The operation of the molds is directly controlled via pneumatic cylinders that ensure proper alignment and minimal distortion of parting lines during demolding. This helps to minimize flash and extend the life of molds by removing interaction with the operator. Demolding and reloading of parts is greatly simplified and faster than traditional methods with quicker turnaround during the unload/load portion of the cycle.

Mold Conversions. Standard molds can be used in the Leonardo design with a simple conversion. They can also be converted back to a standard molding configuration if schedules require.

As a result, the working environment for Leonardo is cool and clean compared to a  traditional rotational molding environment; quality and consistency of parts is improved by reducing the potential for variability in the cycle; mold life and quality is extended; output rates are more predictable.

Future Work:

 

Alternate Materials. By controlling the rate of heating directly at the mold, improved control for sensitive materials is possible. Future work will look at engineering grade materials.

Multiple Piece Molds. Automating the operation of molds with, three, four or more sections will be addressed in the next series of molds and machines under construction.

Addition of Inserts. Adding an automated arm that locates plastic or metal inserts in the mold prior to molding will also be studied. Automating the extraction of insert holding pins may help control part size and shape issues during the cooling stage of the cycle.

For further Information, contact:

Sergio Zilioli

Persico SpA

Via R. Follereau n.4
24027 Nembro, Bergamo
Italy

Tel: +39 035 4531 811

Fax: +39 035 4531 812

Email: sz.rotomoulding@persico.com