20 rapid manufacturing
Innovative production process brings customer benefits Apex Pumps has developed a rapid manufacturing design, development and production system utilising the patternless Replicast process, which removes the need for fixed tool patterns. As a result, the design, development and modification of parts can be completed by the company’s in-house design engineering team using 3D CAD modelling and simulation technology.
A
significant barrier to product development, particularly where pumps are concerned, is the need for investment in costly tooling that can render many projects uneconomical. Replicast negates the need for tooling with replicas (a positive of the component) being made from rapid machined foam, printed SLA components or tooled for blown polystyrene volume production. Use of a rapid casting process has many benefits including lighter casting, less requirement for feed metal, high as-cast integrity and less waste. It also allows for the use of inert ceramic moulds which are more compatible with special steel alloys. Additionally, thanks to the process, end-users benefit from having the ability to specify any number of bespoke alterations to standard pump designs which, as they are manufactured in-house, reduces the products’ carbon footprint and shortens leadtimes. The uses of a sacrificial replica in the Replicast procedure eliminates the need for features such as draft angles and the need for allowances for core float and dimensional inaccuracy, all of which increase the weight of standard sand casting. Replicast does not require these increased tolerances, and weight can be reduced from the raw casting as a result. The shape and form of a finished component are considered from a casting perspective during the design phase, in some instances removing the need for dedicated feed material in areas of the casting. The versatility of the casting process reduces restrictions on component casting orientation. Also, it allows for the casting method to be iteratively developed without the need to modify any fixed tooling. Porosity within castings is the nemesis of any pump manufacturer and targeted calculated feed metal focussed on specific areas of a casting will improve integrity. Improved casting accuracy also enables near net-shape design, reducing required machining allowances and therefore reducing machining times or the need for machining at all on some features. The process is used as standard on Apex Pumps’ API610 11th edition OH2 range, where customer requirements can vary, and the quality and integrity of the parts are vital. The end-to-end production of these pumps on-site allows the company to offer fast lead times where less time is lost with components waiting in a sub-contractors queue Quarter 3 2020
or simply a reduction of transportation between foundries, inspection facilities and machines shops. The process can also be used on some of the more unique customer requirements, including adding safety features such as ribbing, which can be added where pressure or temperature may be an issue. However, it is not possible to increase the overall wall thickness. Specific bosses for the ever-increasing number of sensors attached to pumps can also be added without effecting overall integrity. An excellent example of the benefits of this flexibility with customisation was for a brewery with limited head height. Apex produced ISO pumps with a side discharge enabling the brewery to increase capacity within the same footprint. By combining the process with its in-house micro foundry facility, Apex has been able to reduce its reliance on external suppliers. This provided its customers with an unexpected benefit during the height of the recent lockdown period. Enabling the majority of its production operations to be conducted on-site meant customers, many with critical processes that needed to be maintained, were not held to delays while supply chains were shut down. chevron-circle-right www.apexpumps.com www.bpma.org.uk
