METHOD FOR MANUFACTURING ENVIRONMENT FRIENDLY AIR FILTER
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an environmentally friendly air filter, and more particularly, to a method for manufacturing constituent members such as upper and lower cap for air filter in the form of ring or quadrangle, inner and outer punched plate member, etc. using environmentally friendly cotton fiber and pulp as main material
2. Description of the Related Art
Generally, metallic air filters for automobile remove foreign particles and fine dusts contained in foreign airs introduced into the engine to protect the inside of the engine and decrease noise of the engine and are one of essential elements for vehicles. However, these metallic air filters cause output of the engine to be lowered due to air flow resistance and are harmful to the environment when they are scrapped after the use.
Shapes of the air filters are different depending on kinds of vehicles but a cylindrical shape is most general.
General cylindrical air filters include inner and outer punched plate members but the inner or outer punched plate member can be deleted depending on kinds of vehicles.
Fig. 1 is an exploded detailed view of a cylindrical air filter which is mainly used in large sized vehicles such as bus, truck, van, etc.
Referring to Fig. 1, an air filter includes inner and outer punched plate members 14 and 18 through which a plurality of punched holes are formed. A vertically corrugated filter paper is inserted between the inner punched plate member 14 and the outer punched plate member 18.
In order to maintain constant interval between the inner and outer punched plate member 14 and 18 and the filter paper 16 and fix their forms, ring-shaped upper and lower caps 12 and 20 are respectively coupled to an upper opening and a lower opening of a cylindrical member made of the inner and outer punched plate members 14 and 18 and the filter paper 16.
Here, the outer punched plate member 18 is provided for preventing an introduction of large-sized foreign particles contained in air and the filter paper 16 is provided for filtering fine foreign particles contained the air. Non-described numeral 10 in Fig. 1 is a packing of sealingly fixing the air filter in order to prevent an introduction of the outer air that is not filtered. Fig. 2 is a perspective view of a quadrangle air filter which is mainly used in a small sized vehicle such as a passenger car, etc. The air filter shown in Fig. 2 includes a quadrangle frame 32 and a filter paper 34 coupled to the quadrangle frame 32.
The inner and outer punched plate members 14 and 18, ring-shaped upper and lower caps 12 and 20 and quadrangle frame 32 that are main elements of the conventional air filter are made of chromium (Cr), EGI-plated iron, EGI-plated urethane or synthetic resin. Then, these materials are harmful to the environment. In addition, when disposing waste air filters after the use of them, there frequently occur unlawful burning, unlawful burying or unlawful throwing, thereby generating industrial waste, secondary pollution and environmental contamination.
Moreover, in case where urethane is used as the main material of the elements, due to the characteristic of the urethane material, a bad smell and harmful toxin gases are generated during the burning of the urethane. These toxin gases not only pollute air but break the ozone layer.
Furthermore, in case that the element is made of metal-plated material to prevent the oxidation and corrosion, it is not corroded even after one century and thus badly affects on the environment.
In the meanwhile, in order to save costs and enhance the workability and the processing property, thermoplastic resins are sometimes used as the main material of the elements of the conventional air filter. These resin materials, however, have drawbacks in that they are weak in heat and thus are thermally deformed with ease during the real use, and an ability to maintain the original shape is very weak.
Thus, although the air filter is consumptive article that should be periodically checked and replaced, most of elements are of metal, urethane, synthetic resin, etc. except the filter paper. These materials are not desirous in view of the prevention of environmental pollution and the recycling of resources, but the development of a replacing material or an approach to environmental protection is not yet accomplished.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to resolve the aforementioned problems and to provide a method for manufacturing an air filter of new environmentally friendly paperboard which is not harmful to the environment after burning the same and is naturally decomposed as buried.
To accomplish the above object, there is provided an improved air filter by separately preparing upper and lower caps and inner and outer punched members using cotton fiber and pulp as main components and then performing a cutting, forming, punching and assembling step.
According to technical features of the present invention, paperboards for upper and lower caps are formed using cotton fiber and pulp as main components. The paperboard for the caps is cut in a specific form depending on sizes every kind and is dipped in water for 30-120 seconds and is pressed on a corresponding mold.
Independently with the forming of the paperboard for the caps, paperboards for inner and outer punched members are formed using cotton fiber and pulp as main components. The paperboard for the punched members is placed on a press provided with a punching mold and is
punched using the press at a temperature range of 150-250°C in a pressure range of 80-150
kg/cm2 for 10-30 seconds and is cut in sizes corresponding to regulations of the inner and outer punched members every kind. The cut paperboards for the punched members are adhered in a
temperature range of 70-150°C for 30-90 seconds. A filter paper is inserted between the
manufactured inner punched member and the outer punched member. Both ends of the inner and outer punched members with the inserted filter paper are coupled to the upper and lower caps with glue. The coupled caps and the punched members are dried in a drying furnace.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a general cylindrical air filter; FIG. 2 is a perspective view of a general quadrangle air filter; and
FIG. 3 is a flow chart showing a method for manufacturing an air filter in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing an air filter in accordance with a preferred embodiment of the present invention is described in detail with reference to the accompanying drawings.
First, a paperboard having sizes of 1, 000 X 1,200mm, 500X600mm, 750X900mm, etc.,
in a thickness range of 0.7-3.0 mm is prepared for the manufacturing of upper and lower caps. . (S210)
The paperboard contains cotton fiber and pulp as main components and it may additively contain another component(s) as an additive. The cotton fiber and pulp which are natural high molecular substances used in the present invention are low in hygroscopic property, inflammability and ignition property but are very excellent in soundproof property and thermal insulation property.
The prepared paperboard is cut using a cutting blade such that it has a proper size and shape necessary for regularized upper and lower caps depending on kinds of air filters applicable to various vehicles. (SI 04) After that, in order to enhance toughness and moldability of the cut paperboard, the workpiece is dipped in water for approximately 30-120 seconds. At this time, when water content contained in the dipped paperboard is large, the pressing time is lengthened, resulting in the lowering in the economics and productivity, while when the water content is small, tensile strength is lowered, which causes a failure such as fracture of the caps, the occurrence of air bubble, etc.
Next, the cut and dipped paperboard is mounted on a mold depending kinds of the caps
and is then pressed using a hydraulic press at a temperature range of 150-250°C, in a pressure
range of 80-150 kg/cm2, for 10-30 seconds, thereby forming the upper and lower caps. (SI 06)
At this time, if the temperature range is too high, the pressing time is too long, or the pressure is too high, the cap is fractured, its surface becomes rough, or air bubbles are generated.
In the meanwhile, if the temperature range is too low, the pressing time is too short, or the pressure is too low, the tensile strength of the cap is lowered and thereby the shape of the cap is deformed.
Independently with the preparation of the paperboard for the upper and lower caps, paperboards for inner and outer punched members containing cotton fiber and pulp as main components are manufactured in a thickness range of 0.7-3.0 mm. (SI 08)
The inner and outer punched members paperboards as manufactured may be made of a material having the same components and compositions as the material for the upper and lower caps and preferably be made of a material having a composition ratio of cotton fiber and pulp having more enhanced tensile strength than the paperboard for the upper and lower caps.
The inner and outer punched members paperboards are placed on a press providing with a punching mold, more preferably a hydraulic press and are then punch-pressed under a pressure of80-150 kgf/cm2. (S110) After that, the punch-pressed paperboards for the inner and outer punched members are cut such that they have proper sizes and shapes necessary for regularized upper and lower punched members depending on kinds of air filters applicable to various vehicles. (SI 12)
Thereafter, the punch-pressed and cut paperboards are adhered using an adhering
machine in a temperature range of 70-150 °C for 30-90 seconds and thus the inner and outer
punched members for an air filter are formed. (S 114)
Then, a filter paper is inserted between the formed inner punched member and the outer punched member, thus forming the punched plate member. (SI 16)
Thus prepared punched plate member is coupled to the upper and lower caps. Specifically, one end of the punched plate member is coupled into a groove of the previously prepared upper cap and is sealingly fixed to the upper cap with glue interposed therebetween and the other end of the punched plate member is coupled into a groove of the previously prepared lower cap and is sealingly fixed to the lower cap with glue interposed therebetween. After the coupling and fixing between the punched plate member and the upper and lower caps are performed, the air filter is dried in a drying furnace. (SI 18 and SI 20). The upper and lower caps and inner and lower punched members fabricated using cotton fiber and pulp have nearly the same tensile strength as those fabricated using metallic material. Also, they have excellent heat-resistant property, water-resistant property and deformation- resistant property. Further, they are lighter in weight compared with the conventional metallic air filter, enable to burn them without occurrence of harmful toxin gases, and are naturally decomposable after they are scrapped. As a result, their use decreases the environmental contamination as well as amounts of scrapped articles. Moreover, since the cotton fiber and pulp provide outstanding sound insulation property for the air filter, noise generated during absorbing air into the engine decreases remarkably. As described previously, since the present invention manufactures elements for an air filter using paperboard made of environmentally friendly cotton fiber and pulp as main components, waste air filters are naturally decomposable after they are buried or burnt. As a result, environmental contamination decreases compared with the conventional air filters made of metal, urethane, synthetic resin, etc. Further, the air filter of the present invention is light in weight compared with the conventional air filters and it also allows noise generated during absorbing air into the engine to decrease remarkably since the cotton fiber and pulp materials provide outstanding sound insulation property.
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