Title of Invention	METAL FREE FILTER AND METHOD FOR THE MANUFACTURE THEREOF
Abstract	The present invention relates to a metal free filter and a method for the manufacture thereof. In particular, the present invention relates to a metal free filter for automobile use and to a method for the manufacture of a metal free fiber for use in automobiles and other applications.

Full Text

FIELD OF THE INVENTION The preseat invention relates to a metal free filter and a method for the manufacture thereof. In particular, the present invention relates to a metal free filter for automobile use and to a method for the manufacture of a metal free filter for use in automobiles and other applications. BACKGROUND OF THE INVENTION In the prior art, filters are manufactured with metallic end caps, which are joined with filter paper commonly using PVC based adhesive. Both ends pleats of the filter paper are -joined with a metallic ^side-sealing clip. Filters for use in automobiles being replaceable items, the generation of waste is very high. This problem is compounded considering the increase in the number of vehicles on the road Disposal of metal end cap based filters resulrs in tremendous disadvantages in terms of the time taken to dispose off, the expense involved and the generation of non-reusable or non-biodegradable waste. In a metal type filter., the filter media itself is easily incinerated. However, during incineration PVC based adhesive produce unwanted byproducts such as polyvinyl chloride and undesirable chlorine thar are harmful to the ozone layer and pollute the environment. In addition, the metal end caps are not incinerable and therefore require recycling at higher temperatures. The waste — management problems of the Developed and developing States continually threaten to reach crisis proportions. Industrialized countries have generated a lot of garbage for a long time; there is no single, simple answer to this problem. Actions have thus been taken by the plastic industry here and abroad to make positive steps towards helping to reduce plastics waste by recycling, incineration, etc. Recycling of waste has become an important approach and a profitable business. Technically, plastics can be one of the easiest materials to recycle. Business opportunities are gradually developing to produce many different products from recycled plastics such as detergent bottles, office equipment, highway barriers, wastebaskets, pallet strapping, tool boxes, fast food trays, park benches, carpeting, irrigation pipes and many others. Incineration solves many solid - waste disposal problems: Done properly, it can reduce the volume of solid waste by at least 90%. In addition, waste-to-energy plants provide a reduction in disposal costs. Plastics have the highest stored energy value of any material and also the lowest energy cost to produce and process into products. One solution to this problem has been to try to replace the metal end caps with end caps made of plastics that can be easily disposed off Fibers with plastics end caps are easy to dispose off. They burn cleanly, producing emission of carbon dioxide, nitrogen oxides and water vapor. So they are easy to incinerate and environmental friendly. If plastic caps are recycled then they develop new business opportunities and produce different products from recycled plastic. Plastics have the highest stored energy value of any material and the lowest energy cost to produce and process into products. 1 Published German Patent Application No. DE 4.206,519 discloses a filter arrangement, which comprises an annular fiber element. This annular fiber element comprises an accordion-folded (or zig-zag folded) fiber material On the axial end faces, cover plates or sneets 01 sealing material are arranged which each seals tightly because they are connected to the fiber material. The sealing material is shaped in the form of a radial seal; that is, it projects a certain distance radially inwardly beyond the fiber material and, together ! with a housing connection piece, forms the sealing element. Such radial sealing devices are subjected to very high tearing stress. There is a danger that the sealing material will tear when the filter element is inserted into the filter housing and, as a result, not only will the sealing material be damaged, but the effectiveness of the fiber will also be compromised. Although the publication attempts to establish a defined radial sealing dimension by means of a supporting ring, if this supporting ring is to have an effect, it must be relatively thick-walled and therefore considerably reduces the inside diameter of the housing connection piece. Published German Patent Application No. DE 2,429,474 (=GB 1,511,904) discloses a filter element in which a radial seal is formed by sealing lips, the radial seal also being integrated into the end plate. It is a disadvantage of these sealing lips that these are constructed to be very beaded. The sealing lips therefore considerably reduce the diameter of the housing connection piece or enlarge the outside diameter of the filter element. US Patent 5736040 discloses a fitter arrangement formed with housing and a center tube connected with the housing. A metal-free filter cartridge is arranged which includes an accordion-folded, annular filter element. The filter cartridge is provided with end plates on the axial end faces of the annular filter element, at least one of the end plates having an elastic construction, and each elastic end plate is provided with a flexible supporting ring which is arranged directly adjacent a radial seal formed by the elastic end plate. US Patent 6423108 discloses an air filter for an internal combustion engine having housing and a filter element, which is arranged in the housing. The housing is provided with a filtered air outlet and at least one untreated air inlet with a screen or a closable flap. An auxiliary untreated air inlet, which is closed by a flap valve, is also provided. The screen or the flap of the untreated air inlet opens when the temperature of the untreated air is above a certain threshold value and closes when tile temperature of the untreated air is below a certain threshold value. OBJECTS OF THE INVENTION Accordingly, it is an object of the invention to provide a metal free fitter that is easy to replace. It is another object of the invention to provide a metal free filter that provides better performance than prior art filters of both metal type and metal free type. It is further object of the invention to provide a metal free filter that is environmentally safe and does not result in disposal problems on replacement. SUMMARY OF THE INVENTION Accordingly, the present invention comprises a metal free filter comprising a filter element provided with a predetermined pattern and provided with two opposing ends, the filter element being wound around a central tube means, plastic end caps being connected to the said opposing ends of said filter element by means of a weld layer comprising molten plastic. In one embodiment of the invention, the filter element comprises of filter paper pleated in the form of a zig-zag shape with dimple provided at even distances on the surface thereof so as to create interstitial spaces between succeeding pleats of the filter-element. The invention also relates to method for the manufacture of metal free filter for automobile use said filter comprising a filter element provided in a predetermined pattern and provided with two opposing ends, plastic end caps being connected to the said opposing ends of said filter element by means of a weld layer comprising of molten plastic, said method comprising providing a weld layer between the said plastic end caps of the said opposite ends of filter element and sealing the said opposite ends of the filter element to respective plastic end caps under high temperature. In one embodiment of the invention, the sealing is done by ultrasonic welding. In another embodiment of the invention, the sealing is done by heat welding. In another embodiment of the invention, the end caps comprise Polyamide grade end caps. In a further embodiment of the invention, the sealing layer comprises PA based hot melt. In yet another embodiment of the invention, the paper filter element is joined to the polyamide end caps with hot plate joining technique. In yet another embodiment of the invention, the cutting of the filter felt is done by ultrasonic cutting technique. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING DETAILED DESCRIPTION OF THE INVENTION In die prior art filter manufacture systems, the use of PVC based adhesives results in several disadvantages such as the chances of bypass. This is avoided in the present filter manufacturing method since the filter paper becomes an integral part of the polyamide based end cap and use of polyamide hot mete for sealing the two end layers, This procedure of avoiding metal in the filter end caps also ensures that complicated shapes are easily achieved without a substantial increase in costs. The use of thermoplastic as end cap material while presenting a challenge initially in terms of manufacture was selected due to potential advantages such as the use of less raw material, lower scrap volume and consequential lower environmental burden and reduced > waste disposable problem. Other advantages are that the element assemblies are corrosion resistant and do not require separate plating as is required in prior art metal caps. The use of polyamide end caps also ensures that complicated shapes of end discs are easy to make since plastics are easily moldable and are light in weight It was also postulated that the use of lightweight filters would result in increased engine efficiency. Raw material cost of end discs is less as compared to existing metal cap and adhesive cost. In view of the decision to use polyamides grades which are thermophilic, it was decided that ultrasonic welding and hot plate welding could be tried to join the end pleats and filter elements with the end caps to ensure a permanent seal without loss of performance. It was also observed that the bypass of filter is less as compared to existing filter using metallic. components was less because in plastic component design paper is directly embedded in end cap. In existing design, paper is bonded with metal end cap with adhesive . Lite of filter increases since paper is embedded less than metal cap collar length so more paper is available for filtration. As more filtration is possible in the same geometry. The metal free fiber of the invention can be used for both oil and fuel filter applications. It is another part of the invention that the pleating design can be varied according to the filter design, desired filter output, the filter material input, customer requirements and other factors. Commonly below mentioned pleating are used in oil/ fuel and air filter application. Cloth type filters for fuel application are also bonded with these techniques. However, different pleating design such as star type pleating whether grooved or dimpled, zig zag pleating, nt-type pleating, coil type pleating, can be accommodated with these techniques. There are several advantages in cross dimpling of the filter media. Effective filtration area is increased. When filter media as pleated and assembled in packs in other designs, grooved/projections on the filter media of two adjacent pleats overlap/come in contact with each other thereby reducing effective filtration area. However, in the filter of the invention, the grooves are not perpendicular to end pleats. Grooving in a zig-zag manner ensures that when two adjacent pleats overlap/come in contact during assembling then only central portion of grooving comes in contact. The center tube design also provides several advantages such as grooving helps in improving the strength of center tube, lesser thickness provides the same strength thereby resulting hi saving of material, grooving helps hi pleat distribution, in new design by providing fillet radius effective filtration area increased since less paper comes in contact with center tube. Element pack is joined with end caps through hot plate welding technique. In this technique end caps are heated against a hot surface, allowed to soften sufficiently to produce a good bond, then pressed together while bond sets. Paper and plastic caps become integral part by this joining technique. Viscosity of end caps decreases with time as it changes from a solid state to a liquid state under the action of heat. Once the melting point is attained after a certain time, if no temperature change occurs, the molten mass viscosity also remains constant for a certain time (10 to 20 min.), beyond which the thermal degradation of material may set in. As thermoplastic melt has the lowest viscosity (and consequently the highest fluidity), which is maintained for several minutes. This allows the paper to be injected into die melt. Special fixtures are employed to maintain parallelism, flatness of end caps and uniform embedment of the pleated filter paper. The apparatus for manufacture is given inxFigure 1 in the form of a schematic. A special heating mechanism ensures the uniform melting of end cap at all the point in a lesser time with improved performance. In that machine ceramic workstation dies are there to locate end caps. Pre-molded end caps are used in this machine. Pre-molded end caps are placed in ceramic workstation die that is connected with slide mechanism. Complete machine is PLC (i» controlled to ensure the exact cycle time execution of each operation at all the time. After putting the end cap slide moves from that position to cap heating zone. Heating mechanism heated the end cap upto a fixed programmed time depends upon type, design of filter and material of end cap used. In this process temperature of end cap and the distance between heating mechanism and end cap is very critical. All the critical process parameters dedicated to that part number based upon the initial trials programmed in their logic control if anything goes wrong then machine will not working in that way it ensures the quality of product. Machine continuously monitored the temperature of end cap, which is our ultimate aim and it's a total closed loop system. When the heating of end cap takes place filter media pack is located in pack locator manually, which is connected to cylinder having pressure switch. Scope in present m/c is there to automate this operation. When the heating is completed then slide moves from that position to original position where fiber media pack is embedded in that After heating when work station die with end cap comes at the embedment station then instantly pack locating blocks comes forward to locate filter media pack for proper positioning of pack in end cap. Immediately cylinder moves downward embed the filter media pack in end cap. After pressing the pack in end cap pack locating blocks moves backward and pack locator moves upward. Natural air-cooling is sufficient to solidify the bond between pack and end cap. Same operation sequence repeated for second side of end cap. All the manual loading and unloading operations in this machine can be automated depending on the level of automation required. This machine includes a center tube insertor in case center tube is there in filter elements. Where center tube is not required special locating mandrel is there to locate and help to form the necessary shape and pleat distribution. Table Removed)The method for the manufacture of filters of the invention has several advantages in that the joining technique is fast and can be easily used for mass commercial production. Also, the bonding between the thermoplastic end cap and the filter means cools at a speedier rate enabling the speeding up of the manufacturing process. The use of ultrasonic or heat welding also ensures that the operational costs and material costs are reduced. The overall variation in height of the filters and the consistency of manufacture is also within an acceptable margin thereby reducing wastage. One method by which the metal free fitters can be manufactured is hot melt welding. In this method, the end pleats of paper pack are joined with TPX 16 -192 hot mete. TPX 16 - 192 polyamide is a high melting thermoplastic resin. It exhibits good fuel / oil resistant and adhesion a variety of substrates. Softening point of hot melt is 167 ~ 177° C. The side sealing with hot melt eliminates the chance of leakage in the filter during use and enables easy disposing off by incineration of the final product after use. Another method of manufacture is to use ultrasonic joining. Sealing of end pleats is done by ultrasonic welding technique. This method of manufacture is speedy and economical. While earlier attempts to use ultrasonic joining were not successful due to the difficulty in obtaining uniform resin distribution, the method of the present invention enables uniform bonding strength at all the points. The use of ultrasonic joining is preferred since the machinery cost is low, waste or scrap is not generated, the final product can be easily disposed off by incineration after use while in use, the chances of leakage are eliminated. The filter felt (gasket) is itself cut using ultrasonic vibrations using special dies and punch designed for this specific purpose. The use of ultrasonic cutting enables good dimensional control while speeding up the rate of cutting of the gaskets. Another advantage of the use of ultrasonic cutting of sealed loose fibers is that during cutting, loose fibers across the outer and inner diameter is avoided thereby avoiding the migration of fibers to the engine side. The gasket is joined with end caps of filter with ultrasonic welding technique. Ultrasonic welding is an economical method for joining same or similar plastic based parts. They may not produce good bond if they contain specific fillers, particularly glass fiber if they are of a high concentration. This technique is rapid and can be fully automated. Welding occurs when high frequency (20 to 40 kHz) vibrational energy is directed to the interface between the two parts, creating localized molecular expansion causing the plastic to melt. Pressure is maintained between the two parts after vibration stops, and the melted polymer immediately solidifies. The entire welding process normally takes place hi less than 2 seconds. It has a high strength, which sometimes approaches the strength of the base material While polyamide absorbs moisture, which then has to be removed before the plastics can be converted into acceptable products, low concentrations, as specified by the plastic's supplier, are achieved through efficient drying systems and proper handling of the dried resin before and during molding. The simple tray dryers or mechanical convection hot -air - dryers that may be adequate for nonhygroscopic resins are simply not capable of removing water to the degree necessary for the proper processing of hygroscopic resins or their compounds, particularly during periods of high humidity. The effect of having excess moisture manifests itself in various ways, depending on the process being employed. The common result is a loss in both mechanical and physical properties, with splays, nozzle drool between shot-size control, sinks and other losses that may occur during processing. This is avoided by the method of the present invention. The melt processing temperature of nylon which is a preferred polyamide is in the range of 260 - 290°C. The use of nylon offers several distinct advantages such as high flow and toughness in thin sections, good weld strength and easy fill of complicated shapes, predictable mold and annealing shrinkage with reduced or no warpage, fast overall cycles with the resin being moldable in cold mold, good ejectability of the parts from the molds, good rework stability with reduced property losses on remolding of dry reworked resin blends. It is also another advantage that the processing conditions are unaffected by recycling high levels of blend. Also, multicavity tooling does not present any difficulties in achieving commercial tolerances. It is preferred that the pleating of the filter elements be zig-zag. This enables the reduction of the housing height while retaining the same or greater filtration area. The saving in terms of height reduction of the element assembly and the housing are both in the range of 30 - 40%. The packaging cost is also reduced and the saving in the length of the centre tube is up to 30 - 40%. Other associated manufacturing costs such as transportation costs from initial to final stage, painting cost, inventory costs, painting cycle times, bottom spring height are all reduced due to the use of zig - zag pleating. Selection of material for end caps of metal free filters depends upon type of liquid (fuel/oil) used. Some test fuels shows stress cracking, embrittlement with certain types of thermoplastic when it comes in contact for certain period of time at test and operating temperatures. Some of the test fuels are hygroscopic in nature so it's necessary to check the behavior of test fuel while selection and finalization of materials for end caps. Automobile manufactures and material suppliers continuously searching and testing different grades of plastics which can be used with all types of fuels and they get very favorable results. Acetalcopolymer shows very good results with almost all the test fuels and oils. Thus, different polyamide grades and acetalcopolymer can be used for different end use application with the method of the invention. WE CLAIM: 1. A metal free filter comprising a niter eiement provided with a predetermined pattern and provided with two opposing ends, the filter element being wound around a, central tube means, plastic end caps being counselled to the said opposing ends of said filter element by means of a weld layer comprising molten plastic. 2. Metal free filter as claimed in claim 1 wherein thg filter element comprises of filteii media in the form of zig zag pleats; or 3. Metal free filter as claimed in claims 1 and 2 wherein the pleats are provided with dimples, said dimples being provided at even distances on the surface thereof so as to create interstitial spaces between succeeding pleats of the filter element. 4. Method for the manufacture of metal free filter for automobile use said filter comprising a filter element provided in a predetermined pattern and provided with two opposing ends, plastic end caps being connected to the said opposing ends of said filter element by means of a weld layer comprising of molten plastic, said method comprising providing a weld layer between the said plastic end caps of the said opposite ends of filter element and sealing the said opposite ends of the filter element to respective plastic end caps under high temperature. 5. Method as claimed in claim 4, wherein the sealing is done by ultrasoniojszeldinff nr heat welding or hot plate joining technique. 6. Method as claimed in claim 4, wherein the said end caps comprise Polyamide grade . end caps. 7. Method as claimed in claim 4, wherein the said weld layer comprises Polyamide based hot melt. 8. Method as claimed in claim 4, wherein the cutting of the gasket is done by ultrasonic cutting. 9. Metal free filter substantially as described hereinbefore and with reference to the accompanying drawings. 10. Method for the manufacture of a metal free filter substantially as described hereinbefore and with reference to the accompanying drawing.

Documents:

847-DEL-2002-1-Post-Grant Opposition-(21-03-2011).pdf

847-DEL-2002-3-Post-Grant Opposition-(16-03-2011).pdf

847-del-2002-abstract.pdf

847-del-2002-claims.pdf

847-DEL-2002-Correspondence-Others (11-02-2010).pdf

847-del-2002-correspondence-others.pdf

847-del-2002-correspondence-po.pdf

847-del-2002-description (complete).pdf

847-del-2002-drawings.pdf

847-DEL-2002-Form-1-(11-02-2010).pdf

847-del-2002-form-1.pdf

847-del-2002-form-19.pdf

847-DEL-2002-Form-2-(11-02-2010).pdf

847-del-2002-form-2.pdf

847-DEL-2002-Form-26-(11-02-2010).pdf

847-del-2002-form-3.pdf

847-del-2002-form-7.pdf

847-del-2002-gpa.pdf

847-del-2002-pct-210.pdf

847-DEL-2002-Post Grant Opposition-(16-12-2010).pdf

847-DEL-2002-Post Grant Opposition-(21-02-2011).pdf

847-DEL-2002-Post Grant Oppotition-(01-12-2010).pdf

847-DEL-2002-Post Grant Oppotition-(19-11-2010).pdf

847-DEL-2002-Post Grant Oppotition-(22-11-2010).pdf

847-del-2002-Post Grant Oppsition-(23-11-2010).pdf

847-DEL-2002-Post Grant-Opposition-(18-02-2011).pdf

847-DEL-2002-Post Grant-Opposition-(29-03-2011).pdf

847-DEL-2002-Post- Grant Opposition-(16-03-2011).pdf

847-del-2002-Post-Grant Opposition-(06-08-2012).pdf

847-DEL-2002-Post-Grant Opposition-(23-03-2011).pdf

847-DEL-2002-Post-Grant Oppsition-(23-02-2011).pdf

847-del-2002-Post-Grant-Opposition-(11-01-2011) .pdf

847-del-2002-Post-Grant-Opposition-(11-01-2011)-.pdf

847-del-2002-Post-Grant-Opposition-(11-01-2011).pdf

847-DEL-2002-Post-Grant-Opposition-(16-11-2010).pdf