Product
Filtration
Solution
Croft Filters Ltd, based in the North West of England, was founded in 1986 by two brothers. The company initially traded in mesh, which soon led to an expansion into filter fabrication. Today, Croft manufactures bespoke filters for companies worldwide, supplying to various sectors including pharmaceuticals, engineering and power generation.
As a forward-thinking company, Croft expanded its capabilities in October 2012 by investing in metal 3D printing technology. This decision was driven by Croft’s pursuit of improving the traditional cone filter, an effort previously constrained by conventional manufacturing methods. Mark and Neil Burns identified that aligning the holes in the filter with the system’s directional flow would reduce pressure drop and pumping power, resulting in a more efficient operating system would enhance and improve some conventional filter designs.
Over the last decade of utilising additive manufacturing, we have experienced numerous advantages of the technology. For instance, machine parts consisting of multiple pieces can now be manufactured as a single part from one piece of metal through the additive manufacturing process. One key benefit of this approach is that it reduces material costs, as additive manufacturing uses only the amount needed to create a part, unlike traditional subtractive methods that cuts down larger pieces of material. A further advantage of this manufacturing process is that it allows designers and manufacturers to increase strength and stability, through the addition of localised support.
Tooling time and cost can be reduced, allowing products to reach the market in days rather than months, as time-consuming tooling research and manufacturing are not required. This capability is crucial for industries needing critical parts on a short lead time.
Additive manufacturing also allows for greater design freedom, enabling products to be created cost-effectively and allowing engineers to fabricate multiple versions of a design, fostering creativity. This flexibility also enables us to customise products to meet each customer’s individual requirements.
Croft made the decision in 2016 to develop products using hybrid technology, following the advancement of additive manufacturing at Croft. This approach utilises both additive manufacturing processes and traditional methods, such as laser welding, with the aim of addressing various constraints that could be improved through the combination of these two manufacturing methods.
The first filter manufactured combining both conventional and additive manufacturing methods was the ExoStructure Mesh Filter. Traditionally, mesh is cut and formed into a cone with the help of a jig, it is then spot welded along the seam. A cone filter manufactured from stainless steel 316L mesh holds its shape but can easily be distorted by operator and operation. As a result of using hybrid methods the ExoStructure filter over comes limits previously set by traditional wire mesh filters. Benefits include: increased strength and stability of the mesh woven wire through the addition of localised support. This added strength helps keep the filter’s shape and reduced open area delivering much greater filter efficiency.
A further filter developed using hybrid manufacturing is the disk filter. A key benefit of employing hybrid technology in its production is the ability to easily change the mesh disks to filter to the desired level—something customers can do quickly. With products manufactured as single units, unlike those made with traditional manufacturing, there are no small gaps that could create bug traps where other small elements may also get caught.
