12 Sep Interview for FF Journal
Q: I’ve looked at the white papers available online and they are very informative about the cold forming process. Our readers are metal fabricators, OEMs, suppliers, manufacturers—what latest technological developments might change the way the metals industry looks at cold forming?
A: To give a specific example that may change the views of some readers regarding cold forming, we can consider the potential of this process for achieving a unique surface finish. Cold-formed parts have surface finishes that mirror the smooth condition and dimensions of the dies. Not only does this somewhat ‘burnished’ condition often eliminate the need for secondary finishing, it can also invest parts with the capacity to preserve, for example, gases with zero leakage for a number of years. Recently, Dawson Shanahan engineered a cold-formed aluminium tube for the purpose of holding nitrogen gas. Our customer specified that a minimum pressure must be maintained within the chamber for a period of two years. A rubber seal contacting the chamber inner surface was created to prevent gas loss. It was therefore critical that the chamber surface was free from scratches, eliminating gas leak paths and, in turn, loss of pressure. Although the drawing specification required a 0.2Ra radial surface requirement, the process produced results between 0.04 and 0.08Ra. Cold forming continues to present new opportunities across industry but it is important not to consider cold-forming as a necessarily separate process; it can be allied to other processes in the interest of economy and product quality. Those who may not have given enough thought to cold forming need to consider the fact that, while some configurations, tolerances and/or hybrid designs will always require additional operations, many second operation processes have been eliminated by the expanded capabilities of cold-forming equipment and tooling.
Q: What industries are looking into the process more and more for their products? I read about pharmaceuticals as a possible market – is that new?
A: With the increasing cost of raw materials, many industries, from Aerospace to metal-cutting, are realising that cold-forming offers significant cost-savings, and Dawson Shanahan supplies components to a diverse range of industries.
The medical and pharmaceutical sector certainly appreciates the effectiveness of cold forming in the manufacture of precision components. To illustrate this, we can look at one of Dawson Shanahan’s latest innovations. Created in partnership with a leading drug delivery system company, Dawson has developed components for a revolutionary needle-free syringe that is designed to relieve the suffering of patients with Central Nervous System (CNS) and pain disorders. This ground-breaking product is a drug-device combination that enables the needle-free delivery of subcutaneous sumatriptan for the acute treatment of migraines and cluster headaches.
Dawson Shanahan used intricate cold forming processes to achieve specially engineered parts, including an aluminium chamber and steel ram, with a highly accurate pressure and finish that would enable the drug to be shot into the user’s body without the need for a needle. As a result, medication can be administered quickly, simply and without anxiety. The success of the design is partly due to the high quality mirror finish on the inside of the piston, while the angles in the design also played a crucial role in ensuring that the trigger mechanism works effectively.
Q: What often discourages manufacturers from using cold forming?
A: Probably the fact that cold forming originated as a method for producing simple, high volume components, such as fasteners. But that was the 19th century. Today, the process is capable of delivering precision engineered parts. And just as importantly, given the current climate, cold forming can produce these complex parts with up to 80% less scrap than machine processes. If you add in the facts that cold forming can offer faster lead times, better surface finish and improved mechanical characteristics, cold forming is a strong proposition.
Q: I read that Dawson Shanahan is also working on new ways to work with stainless steel and cold forming—not usually a go-to for manufacturers. How far off is a successful cold forming run with stainless?
A: Very close. The company has had finished parts independently tested by world leading laboratories, which have confirmed that the physical and chemical properties of the stainless steel had been retained during the process. As cold forming retains the integrity of the metal, while also producing parts with highly polished surfaces, the performance of a component can be improved dramatically. The derived advantages of this technological process can be of benefit in a diverse range of areas, from laser applications, where cold formed nozzles can increase cutting precision significantly, to automotive engine parts, such as diesel injectors where stainless steel can replace copper to enhance the overall reliability of engines and achieve reduced CO2 and particulate emissions, especially where biodiesel is used.
Q: How might this process work, or how would it be possible (if you can go into any kind of detail there)—is Dawson’s cold forming process different from other company approaches? And for stainless, how might that process work or be different from typical cases using other metals?
A: The key to cold-forming stainless steel is to prevent galling thus retaining the desirable surface characteristics of stainless steel. The Dawson Shanahanresearch and development department has developed a unique coating and lubrication process that minimises friction when each part is formed and stops galling.
Q: What other developments are in the pipeline that our readers would be interested in learning about concerning cold forming?
A. As Dawson’s expertise in cold-forming becomes better known, we are receiving many enquiries from different industries wanting to achieve cost-savings in different materials; our R&D department relishes the challenges involved.
Q: What do Dawson engineers see as the future for cold forming, short-term, long-term?
A: We see increasing demand for cold-formed components as more industries realise the cost-savings that can be achieved. Our R&D into cold-forming materials currently regarded as ‘non-coldformable’ will open up new opportunities in the long term.
Q: Is there anything I’m not touching upon that you think is worth noting for our readers?
A: Whilst some parts can be completely cold-formed; most components need secondary machining; Dawson’s factories are well equipped with state of the art CNC lathes and machining centres to complement its cold-forming expertise.