Katie Reed from BEC dives into the world of filter manufacturing to explore how injection moulding solves several industry problems
Katie Reed from BEC dives into the world of filter manufacturing to explore how injection moulding solves several industry problems.
Filtration devices are commonly implemented across automotive, bio-medical, marine and domestic appliances, keeping air and water clean, and machinery and appliances functioning smoothly. In industry, the quality and cost of each filter is vital, and injection moulding provides an ideal manufacturing method that keeps costs low and quality high.
The injection moulding filtration process
Injection moulded filter parts begin life as a 3D CAD drawing. Optimised for injection mould tooling, these become the guide for creating the mould tool. Designing out high-cost areas such as non-uniform draft angles, undercuts and inserts at the design stage reduces timescales and additional costs for toolmaking.
Next, material selection is crucial to the longevity and properties of the part, as well as the quality and price. Available materials for both the mesh and the encapsulation framework are wide ranging in origin, application, and cost. Steel and plastic mesh, recycled content, environmental resilience and tensile strength can all be incorporated into injection moulded filters.
Bespoke depth-media, woven and non-woven meshes can be fabricated for filters to provide exactly the level and types of filtration required to ensure their longevity. Nylon is often selected over other engineering plastics owing to its strength and chemical resistance, ensuring that the tough environment’s filters endure.
A Moldflow analysis simulates the material filling the part, allowing for potential quality issues such as weld lines, sinkage or shrinkage to be rectified. Once the design is agreed, a steel tool is produced. Robotically or manually, a filter mesh is loaded onto the core of the mould tool, the tool closes and clamps around the mesh, and molten plastic is injected through a sprue. The plastic flows through into the mould tool, surrounding the mesh. After a swift cooling process, the tool separates and the filter is ejected from the tool, to be trimmed or undergo further assembly.
The benefits of injection moulded filters
Once made, a steel mould tool can produce up to millions of identical filter mouldings. This high-volume repeatability and precision help ensure that filter manufacturer’s products are made to a high quality. Stringent inspection, testing and documentation throughout the manufacturing process ensure these are maintained.
Aside from the initial cost of tooling, injection moulded filters present a very low cost-per-part solution. In particular, for large-scale production, this cost-per-part decreases even further.
Any waste plastic or rejected mouldings used in injection moulding filter production can be re-ground for recycling or immediate use. Injection moulding machines are increasingly energy efficiency, particularly hybrid and all-electric models.
Katie Reed from Bec says: “Injection moulding as a filter manufacturing process allows for cost savings (particularly at scale), while it incorporates flexibility over design and material selection. Repeatability and strict control of process variables ensure tight quality control.”
