As a provider of comprehensive solutions, Norafin focuses on products that fulfill a wide range of filter media requirements to improve the filter and to protect the environment from hazardous emissions worldwide by developing and producing hydro-entangled materials as shown in figure 1. The filters have an improved nonwoven filter surface with an increased number of finer pores and a uniform cross-section, resulting in an excellent filter performance.

Norafin took part in a joint project with the main goal of developing nonwovens, loaded with metal particles (particle content approx. 70 – 90 % by weight), corresponding to the application-specific requirements of the sintered materials. In the last years Norafin developed this material further together with partners for the sintering process and did the scale up in single sheet or shape as well as roll to roll manufacturing. These new materials now can be used either as particle loaded materials (green body), or after thermal sintering as semi-finished lightweight porous metal structures for diverse applications such as high- temperature (> 500°C) and chemically resistant materials. Either pre-formed hydroentangled or flat materials are used as basic for the loading process, see figure 2-4. Alternatively, the loaded flat “green body” could be formed into the desired shape and sintered afterwards. This allows new shapes, shorter production processes, and new filter products. The need for alternative lightweight sintered materials is growing in different fields of application and with this motivation we are offering newly developed material and structures to these markets.

We were able to produce a lightweight sintered structure which is structurally stable in many shapes, like pleated elements, flat plates, or complex 3D shapes. The sintered nonwovens based on metal or ceramic particles have, despite their lightweight, flexible structure, excellent pleat-ability, temperature resistance of > 500°C and chemical resistance.

Besides the porosity and the low change of the differential pressure in operation, the filtration and also the fractional efficiency of the sintered nonwovens have been examined with the result that Norafin is able to generate different porous metal or ceramic structures with different filtration properties for varying applications, such as hot gas, high temperature, high pressure or special fuel filtration where known sintered structures have a lower benefit or are not usable yet. (e.g. hydraulic filters, catalysators, heat exchangers etc.)