Silverson Machines Ltd., based in Chesham, Buckinghamshire, has recently invested in two new state-of-the-art die-sink EDM machines from GF Machining Solutions.
The machines, two AgieCharmilles FORM P 600 models, were installed in Silverson’s production facility in April 2018 and are being used, primarily, to machine complex, high-precision rotor/stator workheads - integral components used in the company’s best-selling high shear industrial mixers.
Silverson - the company
For over 60 years Silverson has been at the forefront of industrial mixing technology and innovation, and supplies standard products that include Laboratory scale mixers and assemblies, Pilot scale mixers, Batch mixers, In-line mixers, Powder/Liquid mixing systems, Bottom Entry mixers etc., as well as customised and turnkey system solutions, to a growing global customer base.
Silverson products are used, and are specified, by customers operating in a number of processing and manufacturing industries i.e. food processing, pharmaceuticals, cosmetics, lube oils and petrochemicals etc. The company has customers in over 150 countries and, to service and support this base, operates a network of associated companies, distributors and agents in over 50 countries.
Silverson - the advantage
Silverson mixing systems and solutions help customers reduce process times (by as much as 90% in some instances). In addition to delivering a definite ‘speed’ advantage, the company’s mixing systems are also inherently versatile and cost-effective - with one mixing machine being able to perform a range of different mixing operations such as blending, emulsifying, disintegrating, reducing particle sizes and gelling etc.
Such versatility is achieved by the incorporation of interchangeable workheads.
Silverson workheads are precision machined units. They are manufactured in different sizes and have different designs and configurations depending on their function and end use application.
Workheads are made from 316L Stainless Steel but, for special purpose applications, titanium and exotics such as Hastelloy can also be used. The workheads feature a number of integral components - i.e. rotor blades and circular stators and screens with different-shaped holes, apertures, slots or perforations.
Silverson uses EDM spark erosion technology to machine its stators and screens.
The two new FORM P 600 machines have replaced two older ROBOFORM die-sink EDM machines purchased by Silverson, from GF Machining Solutions, some years ago.
The new machines provide the company with improved productivity and performance and are equipped with sophisticated digital generators and feature a number of onboard SMART technologies that help Silverson achieve higher part accuracies, improved surface finishes, reduced cycle times, reduced electrode wear and greater process reliability.
Says Alan Pepper, Head of Manufacturing at Silverson Machines:
“We regularly invest in new advanced machine tool technologies as a route to improving our performance and competitiveness.
“EDM is a mainstream manufacturing technology for us, and has been for some time. However, to meet the growing global demand for our industrial mixers and to optimise the machining of new sophisticated next generation workheads it became evident that we needed to strengthen, and make further investment in, our spark erosion capacity and capabilities.”
Silverson has long established relationships with GF Machining Solutions and, in addition to investing in AgieCharmilles EDM die-sinking machines, has also purchased (two) Mikron vertical machining centres from the company in the past.
Continues Alan Pepper:
“Having talked to GF Machining Solutions about our immediate and future requirements we were introduced to the new FORM P die-sink machines.
“We were particularly interested the performance of the new machines’ ISPG generators and the IQ technology, supplied as standard on the machines.”
The Intelligent Speed Power Generators (ISPG) in the FORM P 600 machines deliver improved surface quality, material removal and accuracy. The generator reduces electrode wear during roughing and finishing operations - irrespective of whether copper or graphite electrodes are used.
The Innovative Quality (IQ) technology dramatically reduces, and in some cases completely eliminates, electrode wear when using graphite and copper electrodes. The technology helps manufacturers improve their productivity by reducing job set-up times and facilitates improved machine utilisation. It also lowers costs by reducing the number of electrodes required.
Comments Alan Pepper:
“Since being installed the FORM P 600 machines have been working around the clock.
“We are particularly pleased with the low electrode wear we are experiencing and are impressed by the speed of the machines and their ability to produce repeatable high-quality burr-free slots and perforations.
Spark erosion - an enabling technology
In the recent past, prior to investing in spark erosion machines from GF Machining Solutions, Silverson manufactured its workhead components using a combination of turning and welding technologies. Screens, which were bought-in, were made from fine metal mesh and were welded to the turned machined stator.
This process created a number of issues. The weld lines were not aesthetically pleasing and created potential weak spots and contamination areas in the workhead.
The use of spark erosion machine tools in conjunction with copper and graphite electrodes has enabled Silverson to simplify and optimise its manufacturing processes and to achieve improved accuracies, reduced cycle times and costs.