Advanced Grinding & Finishing Solutions for the Medical Industry
Advanced Grinding & Finishing Solutions for the Medical Industry
Advanced Grinding Solutions (AGS) has always been closely involved in providing the very best manufacturing solutions to the Medical industry and initially started off by selling grinding and polishing solutions for the production of artificial knee and hip joints in the 1990s and has gone onto becoming involved in answering industries needs for machines to produce a much larger variety of medical parts. As the medical manufacturing sector has changed, with new processes such as additive manufacturing being adapted, AGS has sought out new methods of grinding and finishing these parts.
Rollomatic, whose 5 and 6 axis grinding machines are widely used throughout the UK and Eire for the manufacture of more cutting tools than any other multi axis grinding machine, also offers machines for the production grinding of medical components of various kinds. Applications include the manufacture of medical drills, routers, burrs, saw blades, screws, reamers and surgical tools such as cranial perforators, anchors, Trocar points, guide wires, tweezers, forceps, scalpels, and rasps. The main advantage of these Rollomatic machines is the kinematic arrangement of the sixth grinding axis that is particular needed when looking to grind medical saw blades. The 6th axis enables the grinding wheels to be inclined and this makes it considerably easier to grind past the center line on a given part without damaging an adjacent tooth or feature. Even more importantly, the contact point of the wheel to the component remains constant over the entire grinding path instead of it altering as the wheel travels around it which is the case on 5-axis grinding machines. The use of the 6th grinding axis also ensures that more freedom to use optimum grinding paths is made possible due to the angular inclination of the wheel and this allows medical parts with very complex forms to be ground. . The surface finish of medical parts is also often critical and is improved by the use of linear motors on the grinding machines. The sealed for life/no maintenance aspects of the linear drives ensure that less or indeed no maintenance is needed and these factors help Rollomatic to offer their industry leading unlimited hours 3 years parts and labour warranty that is free of charge on all new Rollomatic grinding machines. The Rollomatic machines can be viewed on Rollomatic’s virtual exhibition event. See www.digitalrolloworld.com
Gerber polishing and deburring machines, also represented by AGS, are used by companies such as the medical implant manufacturer Medartis AG for de-burring various titanium parts. Medartis was in need of a production method for rounding edges and deburring parts and the Gerber BP-MX brush polishing machine was shown to fulfill that need and create precisely-defined radii or contours on edges with high accuracy. The purchase of the BP-MX machine for the double-sided controlled de-burring of titanium blanks eliminated the previous laborious manual de-burring process. Medartis saw several benefits from the investment they made in the Gerber machines and apart from the labour saving the parts are now better defined, have a regular improved quality, and the process is both easy and automated. Due to its high toughness, parts made from titanium place high demands on machines when machining the parts and defining the process is important. The Gerber machine enables Medartis to produce a perfectly de-burred bone plate
In 2019 AGS came across the GPA Innova D-Lyte polishing machines at an exhibition and after receiving demonstrations and meeting with the Innova team at their works in Barcelona, were appointed as a distributor for the UK and Eire. AGS subsequently took delivery of their own D-Lyte polishing machine for demonstration purposes last year.
This machine is unique and uses the world’s first dry electro polishing process that was developed and patented by GPA Innova. The DLyte range of machines use the patented, single step automated process, for polishing metals by ion transport using free solid bodies. This is a revolutionary dry non-abrasive electro polishing process that does not use any liquid as the electrolyte. These new patented machines polish and deburr medical parts made from nitinol, stainless steel, cobalt chrome, and titanium etc. Typical applications include stents, bone screws, artificial hip and knee joints, cranial and other implants, and any similar medical component whereby fine surfaces finishes to under 0.09um Ra are required without altering the key part geometry after the previous grinding or milling process.
Unlike traditional polishing processes, the DLyte solution obtains a consistent finish avoiding generating any polishing marks on the surface, such as those generated by conventional machining, and is able to process complex geometries without generating any micro scratches on the surface which is the case with robot based belt polishing or machines using barrels filled with hard media. Chris Boraston, Managing Director at AGS, comments that after seeing the DLyte machine he immediately recognized just how unique and special it was and the many advantages that it brings for the polishing of a wide variety of medical parts; many of which are ground on the grinding machines already sold by AGS.
The medical industry was amongst the first to benefit from using the D-Lyte machines for polishing implants. The typical process to finish implants was previously based on using mechanical abrasive based processes like robotised belt polishing cells or vibratory bowl type polishing machines. These type of process’s work by generating friction onto the workpieces surface from a generic abrasive belt or hard media. Although there are other procedures that involve dry polishing, this type of polishing primarily refers to circular bowl type vibrators. These may be used to round part edges and to polish the surface of implants. Those processes tend to present issues as they can be error-prone and it’s hard to certify a specific success-scale as they don’t offer a true consistency of results. These processes are not usually as reliable as the DLyte process and often require additional manual rework to achieve the desired finishing results. D-Lyte machines achieve a superior surface finish than abrasive polishing type machines and the process can be more than 5 times quicker than mechanical abrasive machines and for the Medical Industry, DLyte has proven the Biocompatibility of the medical products processed using the DLyte System.
The 3D additive manufacturing of implants and other medical components is becoming the norm and not only are the DLyte machines also suitable for polishing metal additive manufactured implants they provide superior results than existing surface finishing technologies. This is crucial as one of the main issues that additive manufacturing has is being able to achieve a good surface finish after the parts have been produced.
An independent surface finishing study carried out by the Fraunhofer Institute for Additive Manufacturing Technologies looked at the various machines and processes used for the surface finishing of titanium and stainless steel additive manufactured parts. It considered, amongst other criteria, the surface finishes obtained, erosion rates and effects, and the edge rounding of inner and outer edges. Various finishing processes were benchmarked against each other including abrasive blasting where a stream of abrasive material such as sand is propelled onto the surface under a high pressure, vibratory bowl finishing, chemical and electro polishing, and shot peening. The DLyte process achieved not only the best surface finishes but it was at least twice as good as the next best alternative process.
Anyone interested in any of the advanced solutions offered by AGS can view videos and download additional information from the AGS website www.advancedgrindingsolutions.co.ukor contact AGS on +44 (0) 2476 22 66 11
Managing Director at Advanced Grinding Solutions Ltd
Our range of machines is supplied to numerous companies all around the world and the leaders in industry use these to great affect.
We have many thousands of worldwide references but customers that we have supplied equipment to here in the UK include, amongst others: