RAW MATERIALS FOR TRACK ETCHED MEMBRANE FILTERS
We apply track-etching technology to fully transparent POLYCARBONATE (PC) and POLYESTER (PET) raw films, as well as to brownish yellow POLYIMIDE (PI) film, available in various thicknesses ranging from 6 to 50 microns.
polyethylene terephthalate (PET)
We only use high quality materials providing their intrinsic properties to all track-etched membrane filters: low extractable, low protein binding, negligible adsorption and absorption, biocompatibility, excellent chemical resistance and thermal stability.
Available thicknesses for raw materials
|thickness||polycarbonate (PC)||polyester (PET)||polyimide (PI)|
|6 µm (*)|
|10 µm (*)|
|(*) available as cast or extruded film|
Intrinsic properties of raw materials
Used polymer films provide their intrinsic properties to track-etched membrane filters: low extractable, low protein binding, negligible adsorption and absorption of filtrates to maximise critical solution recovery, biocompatibility, excellent chemical resistance and thermal stability.
UNIFORM PORE SIZE BY TRACK-ETCHING
The physical mechanism at the base of the pores appearance during the track-etching process ensures a precise and uniform pore diameter, intrinsically yielding a narrow pore size distribution and providing sharp cut-off filters.
This outstanding shape and dimensional control enable efficient and accurate size exclusion of particles during any filtration process, this make them suited for the most demanding filtration operations, and also for more specific demands such as template for the synthesis of 1D nano- or micro-objects.
(left) Slightly tilted pictures of the surface of a track-etched membrane filter showing regular and homogenous pores
(right) transversal cut showing straight and cylindrical pores crossing all the membrane filter thickness
pore diameter = 0.4 micron (by scanning electronic microscopy)
WIDE RANGE OF POROSITIES AND FLOW RATES
Track-etching technology is most suitable for an independent control of both pore size and pore density: pore density is defined during the first step of the process while pore size is defined by etching conditions.
Current beaming conditions can be finely tuned to obtain a pore density ranging from 1,000 pores per square centimetre to more than 1E+09 pores per square centimetre.
Pore size range
Air and water flow ranges – in L min-1 cm-2 @ 0.7 bar (10 PSI)
Selection of pore size and of pore density, combined to the choice of filter thickness, enable the manufacturing of track-etched membrane filters characterise by a wide range of water and of air flows.
Suitability for advanced pore structure
If common track-etched membrane filters are made of multi-angle pores, the flexibility of the beaming process enable us to achieve alternative porous structures.
multi-angles from 45° to + 45°
straight pores (90°)
+45° / -45° pores
SCREEN FILTERS IDEAL FOR ANALYSIS OF RETAINED PARTICLES
Because of the homogeneity of the pore size and of the pore shape created by the track-etching process, track-etched membrane filters used for filtration retain all particles larger than the pore size on their flat and smooth surface. The retained particles are therefore easily recovered or easily detected and analysed by any appropriate detectors.
Bacteria retained on the membrane surface after filtration of a sampling control through pores smaller than bacteria dimensions (pore size = 0.4 µm).