Determination of filtration level and porosity in Additive Manufactured porous filters

Croft Filters开发了一种金属多孔过滤器产品系列，可以在几微米范围内提供过滤。这种过滤器类型在工业中用于去除生产过程中流体中的小颗粒，以防止对过程的损害和产品污染。增材制造（AM）技术用于制造金属AM多孔过滤器。过滤器是逐层构建的，并且通过使用不同的构建设置，可以增加或减少过滤器的孔隙率。过滤器的形状和尺寸可以定制，以适应个别最终用户的应用。增材制造不需要模具，金属粉末可以回收利用，从而减少材料浪费。金属烧结过滤器，提供低微米级的过滤，未来的市场份额将达到27亿美元，到2030年，然而，这一市场增长的限制是生产线的定制，包括模具，这会延迟制造。AM多孔过滤器的生产无需工具，这允许快速定制和生产，从而进入该市场。然而，Croft无法为客户提供过滤器规格。传统的过滤器，由编织丝网制成，具有已知的孔径大小，即过滤水平。已经使用X射线计算机地形图、汞测试和高粉末显微镜来寻求该过滤水平的确定，但是没有供应商能够准确地确定孔径，从而确定过滤水平。NPL在初步研究中提供了指示性证据，即颗粒测定能够提供Croft多孔AM过滤器的过滤规格的途径。在这个坚固的NPL中，将研究颗粒分析，以确定不同密度的金属多孔过滤器的孔径，确定过滤器形状是否影响相同孔隙率的过滤水平，并验证更具成本效益的测量解决方案和技术，这些解决方案和技术可以由Croft直接在自己的场所使用。解决这个问题将使Croft过滤器能够为客户提供过滤器规格，支持销售，并将支持市场渗透，从而增加收入和市场份额。

Croft Filters have developed a metal porous filter product range that can deliver filtration at the few micron range. This filter type is employed in industry to remove small particulates from fluid in production processes to prevent damage to processes and product contamination. Additive Manufacturing (AM) technology is used to manufacture the metal AM porous filters. The filter is built layer by layer and by using different build settings the porosity of the filter can be increased or decreased. The shape and size of the filter can be customised to suit individual end-user applications. AM manufacture does not require tooling and metallic powder can be recycled thus reducing material waste.Metal sintered filters, which deliver filtration at a low micron level, future market share will reach $2.7bn by 2030, however a limitation in this market growth is in the customisation of production lines, including tooling, which delays manufacturing. AM porous filters are produced without tooling and this allows rapid customisation and production enabling entry to this market. However, Croft are unable to supply customers with the filter specification.Conventional filters, made from woven wire mesh, have a known aperture size that is the filtration level. Determination of this filtration level has been sought using X-Ray Computer Topography, mercury testing and high powdered microscopy, but no providers have been able to accurately determine the pore size and thus the filtration level.NPL in a preliminary study provided indicative evidence that particle assays could be able to provide a route to filtration specification of the Croft porous AM filters. In this sturdy NPL will investigate particle analysis to determine the pore size in metal porous filters made with different densities, determine if the filter shape affects the filtration level with a same porosity and validate more cost effective measurement solutions and techniques which can be employed by Croft directly on their own premises.Solving this problem will enable Croft filters to provide filter specification to customers, supporting sales and will support market penetration resulting in increased revenue and market share.