Patent Publication Number: US-2010107884-A1

Title: Air filter

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a filter, more particularly to an air filter that is adapted to be mounted on an air circulation path. 
     2. Description of the Related Art 
     Referring to  FIG. 1 , an activated carbon filter  1  for a car, as disclosed in Taiwanese Publication No. 207126, is installed in an air inlet  10  of the car, and includes a plastic frame  11 , an activated carbon filter mesh  12  disposed in the frame  11 , and a plurality of fixing elements  13  for fixing the frame  11  on the car. Each fixing element  13  may be a clamp or a screw. The filter mesh  12  has a sandwich mesh structure, and has activated carbon uniformly arranged within the filter mesh  12 . An outer periphery of the filter mesh  12  is connected integrally to the frame  11 . 
     The main purpose of installing the filter  1  in the air inlet  10  of the car to allow the filter mesh  12  to filter dirt in the air and to allow the activated carbon in the filter mesh  12  to remove unpleasant odors in the air. However, the filter  1  cannot provide a fragrant odor after filtering the dirt and bad odor in the air. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the present invention is to provide an air filter that can provide a predetermined fragrance to enhance the quality of air after filtering. 
     According to this invention, an air filter is adapted to be mounted on an air circulation path, and comprises a filter body, an activated carbon layer provided on an outer surface of the filter body, and a fragrance material attached to the activated carbon layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an activated carbon filter disclosed in Taiwanese Publication No. 207126; 
         FIG. 2  is a fragmentary schematic side view of an air filter according to the first preferred embodiment of the present invention; 
         FIG. 3  is a schematic view, illustrating the steps involved in making the air filter of the present invention; and 
         FIG. 4  is an exploded schematic view of an air filter according to the second preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before the present invention is described in greater detail, it should be noted that the same reference numerals have been used to denote like elements throughout the specification. 
     Referring to  FIG. 2 , an air filter  2  according to the first preferred embodiment of the present invention is adapted to be mounted on an air circulation path of a car, an air-conditioning unit, an air filter unit, etc., and is shown to comprise a filter body  21 , an activated carbon layer  22 , and a fragrance material  23 . 
     The filter body  21  may be made of a non-woven fabric, a knitted fabric, a plain jersey fabric, or other fabric material having minute holes that are densely formed. In order to facilitate installation of the air filter  2 , for example in an air outlet of an air-conditioning unit, the filter body  21  may be disposed first in a frame (not shown). 
     The activated carbon layer  22 , in this embodiment, is a coating layer fixed on an outer surface  211  of the filter body  21  through a spraying process followed by a drying process. 
     The fragrance material  23 , in this embodiment, is attached to the activated carbon layer  22  through a spraying process followed by a drying process. Hence, after production, the fragrance material  23  and the filter body  21  are disposed on two opposite sides of the activated carbon layer  22 , respectively. 
     To make the air filter  2 , a roll of screen  20  (see  FIG. 3 ) made from a non-woven fabric, an activated carbon-containing spray liquid, and a fragrant spray liquid are prepared. The activated carbon spray liquid may, for example, include a solution having activated carbon powder contained therein. The fragrant spray liquid may, for example, be an alcohol mixed with fragrance. In this embodiment, the concentration and type of the fragrance have no special limitation. Generally, the fragrance may come from an essential oil extracted from the root, stem, leaf, or flower of a plant, or from a mixture of two or more of such essential oils to form a compound essential oil. The aforementioned fragrance is a fragrant substance that easily volatilizes and that is provided in a high concentration in the fragrant spray liquid. A common fragrant substance may include chemical elements, such as acid, alcohol, aldehyde, ester, ketone, terpenes, and phenol depending on the type and part of the plant from which the fragrant substance is extracted. In combination with the different kinds of the chemical elements, some of the fragrant substances have an effect of reducing inflammation and further provide a calming effect. Arose essential oil is an example of such a fragrant substance. Other fragrant substances have a stimulating effect, such as lemon, citronella, and other fragrant substances with a citronellal aroma. In this embodiment, the fragrance is selected depending on the intended application of the air filter. For example, if the air filter  2  is to be used inside a car, a fragrance having a stimulating effect is preferred. If the air filter  2  is to be used in an air-conditioning unit of a bedroom, a fragrance having a calming effect is preferred. 
     Referring to  FIG. 3 , the roll of screen  20  is advanced along a predetermined direction. Two spray devices  31 ,  32  are disposed spaced apart from each other along an advancing path of the screen  20 . The spray device  31  contains the activated carbon-containing spray liquid, while the spray device  32  contains the fragrant spray liquid. A drying device  33  is disposed between the spray devices  31 ,  32 . An additional drying device  34  is disposed rearwardly of the spray device  32 . When the screen  20  advances continuously and passes the spray device  31 , the activated carbon-containing spray liquid is sprayed on an outer surface  201  of the screen  20 . When the screen  20  passes through the drying device  33 , which has a temperature of about 160° C., the activated carbon liquid spray on the outer surface  201  of the screen  20  is heated and hardened, so that a coating layer of the activated carbon layer  22  is formed on the outer surface  201  of the screen  20 . As the screen  20  with the activated carbon layer  22  advances to the spray device  32 , the fragrant spray liquid is sprayed onto the activated carbon layer  22 . When the screen  20  with the fragrant spray liquid passes through the drying device  34 , which has a temperature of about 160° C., the fragrant spray liquid is heated and hardened to thereby form a coating layer of the fragrance material  23  on the outer surface  201  of the screen  20 , and thereby complete formation of the air filter  2  of the present invention. The screen  20  is then cut to a suitable length as needed. 
     In use, when air passes through the air filter  2 , large particles of dirt are filtered by the filter body  21 , and an unpleasant odor in the air is filtered by the activated carbon layer  22 . As the air passes through the fragrance material  23 , scented air with a predetermined fragrance is produced and uniformly distributed inside the car or room. Hence, the air filter  2  of the present invention not only can filter impurities and unpleasant odor, but can also improve the scent/odor of the air after filtering the same, thereby enhancing the quality of the resulting filtered air. 
     Referring to  FIG. 4 , an air filter  2 ′ according to the second preferred embodiment of the present invention is shown to be similar to the first preferred embodiment. However, in this embodiment, the fragrance material  23 ′ includes a plurality of spaced-apart fragrance-containing sheets  231  fixed to the activated carbon layer  22 . To fix the fragrance-containing sheets  231  onto the activated carbon layer  22 , the air filter  2 ′ further includes a covering layer  24  overlying the fragrance-containing sheets  231  and the activated carbon layer  22 . The covering layer  24  is made of a material having minute holes that are densely formed, such as a non-woven fabric, a knitted fabric, a plain jersey fabric, etc. The covering layer  24  may be sewn or tied to the filter body  21  so as to position fixedly the fragrance-containing sheets  231  onto the activated carbon layer  22  and to sandwich the fragrance-containing sheets  231  between the filter body  21  and the covering layer  24 . The effects of the present invention described in the first preferred embodiment may also be achieved using the second preferred embodiment. 
     While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.