These three benefits can have a substantial impact. Throughput is a critical metric in new equipment purchase decisions, and for those with existing equipment the ability to increase throughput can transform a process and negate the need to purchase new equipment. Add to this the ability to optimize the use of available labor and improve parts consistency, and automated powder filling of dry bag isostatic presses presents itself as a significant competitive advantage.
Gasbarre Press Division offers three types of automated powder filling systems for new or existing equipment:
Volumetric Filling System (VFS)
If your application powder has good batch-to-batch uniformity, then consider a Volumetric Filling System (VFS). These systems offer easy adjustment and programmable repeatability. They also incorporate quick change volumetric range calibration customizable for almost any application.
Mass Filling System (MFS)
In applications with temperamental powders or where part-to-part weight consistency is crucial, a Mass Filling System (MFS) is available, again with programmable repeatability. These systems are excellent for parts that will be green machined after compaction.
Level Filler System (LFS)
For set-it-and forget it repeatability with free-flowing powders and minimal tool changes, Gasbarre now offers the Level Filler System (LFS). The LFS utilizes the fact that when powder flows through an orifice and finds its level, it stops flowing. A timer controlled, spring-loaded valve controls the amount of powder within the molding bag, and is calibrated for a specific range of molding bag fill diameters, providing excellent repeatability.
Gasbarre offers an extra-long fill tube option for higher density powders in order to mitigate the effects of gravity, improving the apparent density uniformity as a long molding bag is filled. The fill tube is inserted from either a VFS or a MFS to the bottom of the molding bag, filled with powder, and then extracted as the total dose is fed from the tube.
Gasbarre can custom design an automated filling system for a new dry bag press, retrofit most presses, and train your operators.
For those that have been won over by the advantages of dry bag isostatic pressing – and who wouldn’t be with the increased productivity, improved parts consistency, reduced material waste, and vastly reduced risk of contamination compared to competing technologies – the next challenge quickly becomes: how do I know what to buy? Rest easy, because this article was written with you in mind.
Consideration #1 – Sizing the Product
Be sure that the press can accommodate the length (typically a maximum of 470mm/18.5”) and required fill diameter (up to 155mm/6”) for your part. Because things have a way of changing over time, determine the degree of flexibility of the press – if and how product sizes can be changed through the use of adapters and the availability/cost of those adapters. Finally, based on required density of finished parts, ensure that the press pressure is sufficient for the job but not overkill – dry bag isostatic presses have maximum pressures of approximately 35,000PSI.
Consideration #2 – Throughput
The purchase of any new piece of equipment hinges highly on its ability to pay for itself. In the case of process equipment, this ultimately leads to the big question: how many parts per minute, per hour, per shift can be produced? When quoted cycle times from the equipment manufacturer, be sure the estimated cycle time is relevant to the specifics of the process in question – powder flow, availability of automation, dwell times, etc. all can significantly affect throughput.
Consideration #3 – Look to Potential Problem Areas (Used Presses)
When considering a used press, look to the quality of the sealing membrane and avoid (or take note of) a rusted or seized pressure vessel clamp. Theseare key points that can quickly degrade the performance of the machine and necessitate the purchase of a new pressure vessel.
Consideration #4 – Support
The purchase of a dry bag isostatic press is the beginning of a relationship. Dry bag presses are designed for years of daily operation under stressful conditions, and when well maintained and cared for they deliver trouble-free operation. However, the reality is that at some point in the life of the machine, support from the manufacturer - advice, on-site service, or parts - will be required. Be sure you’re working with a company that can provide all this in a timely manner, and has the right people in the right places to do this. Ask about the availability of on-site service, what spares they keep in inventory, and how customer requests for assistance are managed.
You’ve chosen a great and proven technology. With these basics in mind you can be confident that you are making the best selection among potential suppliers. Good luck!