Sprint Filter Via Lombardia, 11 20010 Arluno (Milano) Italy
Cod. Fisc. e Part. IVA IT08385740157 R.E.A MI 1220290 Reg. Imp. MI 146-260287
Tel +39.02.90377518 Tel +39.02.90377519 Fax +39.02.90377520 www.sprintfilter.net
PATENTED REVOLUTION After two years’ trials on the racing tracks with the best world Teams, Sprint Filter is pleased to launch its patent that will allow it to be the only world company to manufacture air filters for combustion engines with water-‐repellent filtering elements that will prevent liquid substances to pass through them. With this in mind Sprint Filter presents its range of P08 W.P. air filters with a special water-‐repellent treatment allowing them to be used in bad weather conditions. Vehicles using air filters with external suction (generally conical or cylindrical in shape) in particular will benefit from this great innovation. It is in fact undisputed that vehicles fitted with a case-‐less air filter encounter various problems when it rains or if they come into contact with water or other liquids. Any air filter directly exposed shall get soaked and allow the liquid to enter the combustion chamber. In this case the combustion chamber shall receive not only the liquid but also all the dirt blocked by the filtering element as well as the dirt present in the rain or mud. No longer pre-‐filters or thick molasses The great advantage of the Sprint Filter patent is that it’s no longer necessary to use pre-‐ filters (mostly in polyester) that take air from the engine. In fact Sprint Filter deems it absurd to have to cover an air filter with a different type of material to trap dust (in the presence of sand and dust) or water and liquids in general (in case of rain or use of the vehicle on mud and puddles). Some filters are covered with a very low viscosity oil (commonly called molasses) to trap dust or water. This too affects the passing of air, the duration of the treatment in the presence of water, but above all it increases enormously maintenance times. The technology used The technology used by sprint Filter is the same as for the well-‐known P08 where a special PTFE treatment has been applied based on a formulation that Sprint Filter has perfected in the last two yeas on all soils. The material is the same P08 polyester woven with 5 micron single threads. The obtained yarn is characterized by 80 micron calibrated and certified holes allowing air to pass through twice as much as in any other air filter but with a much higher filtering power. The air filter is totally reconditionable thanks to a few seconds’ cleaning (cleaning with compressed air) and its life is unlimited. P08 W.P. The new range of direct suction filters, called P08 W.P. consists mainly of conical and cylindrical air filters available also with various angles and off-‐centre couplings and can be fitted directly on throttled carburettors with a diameter of between 25 and 70mm.
Sprint Filter Via Lombardia, 11 20010 Arluno (Milano) Italy
Cod. Fisc. e Part. IVA IT08385740157 R.E.A MI 1220290 Reg. Imp. MI 146-260287
Tel +39.02.90377518 Tel +39.02.90377519 Fax +39.02.90377520 www.sprintfilter.net
The tests The degree of water repellence is determined by three parameters: 1) The contact angle between the liquid and the filtering element 2) The liquid intrusion pressure 3) The type of material the filtering element is made of To call a filtering element water-‐repellent, the contact angle must be greater than 90°, otherwise the liquid would pass through its mesh. The filtering capacity of our P08 W.P. has been determined through tests carried out with tensiometers (Kruss K12), following the ISO 811 standard that provides for the sample of material to undergo a test where pressure is gradually increased till water goes through it in at least three different spots. The degree of water repellence can be determined by measuring the angle of contact of the materials. The liquid has its surface tension that causes the spherical shape of drops. When a drop of liquid comes into contact with a solid surface, its shape shall vary according to the interaction created between the liquid and the solid material.
Sprint Filter Via Lombardia, 11 20010 Arluno (Milano) Italy
Cod. Fisc. e Part. IVA IT08385740157 R.E.A MI 1220290 Reg. Imp. MI 146-260287
Tel +39.02.90377518 Tel +39.02.90377519 Fax +39.02.90377520 www.sprintfilter.net
To determine the contact angle the experiment is continued as per the Wilhelmy method by measuring the vertical strength of the sample. To determine the contact angle the following formula is adopted:cos ϑ = F/L x ST (ST= Surface tension) ϑ = f (ST) from which it follows that: 1) if ϑ 90° → idrophilic attraction between liquid and material 2) if ϑ &' ; 90° → idrophilic repellance between liquid and material 3) if ϑ = 90° → neutral material To cover the range of all the liquids involved in the practical applications, 11 types of water/acetone solutions with a surface tension of between 20 – 70 nM/m have been used.
Sprint Filter Via Lombardia, 11 20010 Arluno (Milano) Italy
Cod. Fisc. e Part. IVA IT08385740157 R.E.A MI 1220290 Reg. Imp. MI 146-260287
Tel +39.02.90377518 Tel +39.02.90377519 Fax +39.02.90377520 www.sprintfilter.net
The contact angle method defines the wettability properties of the surface but is not suitable to identify the properties of the woven structure. To complete the job we have also carried out the Water Intrusion Pressure (WIP) test to define the water repellence capacity of the material. To carry out this type of test we used the FX 3000 – IV Hydro Tester. Test conditions: 1°)Material: 23cm² 2°)Pressure: 3mbar/min 3°)Pressure reading carried out on the intrusion of the first drop