Filters with friction spinning flair !

FEHRER DREF 2 friction spinning is nothing if not versatile. It can be used for everything from asbestos substitutes and secondary carpet backing yarns, to technical products such as cartridges for liquid filtration.

At present, around 80 DREF 2 machines are spinning 30,000 t of yarns for liquid filtration. The main markets are Europe and the USA, where some 150 million filter cartridges are manufactured with DREF 2 yarns, a figure that represents 65-70% of global production.

The leading US and European filter producers spin a wide range of DREF 2 PP-yarns at speeds of 160 - 180 m/min. One particular application is for PPFDA washed filters, which are employed in all types of industries from chemicals to pulp and paper, and from cosmetics and pharmaceuticals to nuclear and electrical power. The filter is formed using polypropylene Meraklon fda fibre over a supporting core and can withstand up to 5 bar of differential pressure and temperatures of 80°C. The filters come in all lengths from 4´´- 40´´ and have filtration ratings of 1-150 microns.

Another example of DREF 2 ubiquity in the filter sector is the use of friction spun yarns for drinking and industrial water, pure water and activated carbon filters. A specialist manufacturer employs DREF products for over 20 types of cartridge that require compatibility with FDA foodstuffs legislation. The yarns employed generally consist of PP fibres in the 3.3 dtex, 40 mm range, which are highly resistant to micro-organisms and have a wide scope of chemical applications.

Friction spun yarns offer 20-40% more air volume in the yarn and less flow resistance than flyer yarns, as well as up to twice the service life. The fibre structures are relatively random and subject to high degree of twist. The yarns offer great regularity and increased strength, while their round yarn cross-section ensures limited deformation under transverse load. In addition, production costs are cut by up to 50% through reduced preparation, spinning and personnel expenses. The knot-free, uniform quality of the yarns guarantees fault-free filters and constant micronaire values, with the layered structure creating a hairy surface that is ideal for filtering purposes.

All in all, DREF adds up to an economic and qualitative alternative for spinning with a vast range of fibres. Thus providing the universality and flexibility that the market is seeking.