Abstract:
A system and method is provided for drying for fibers or fibrous materials, such as flax, hemp, jute, sisal, banana and coir, among others by dehumidifying the fibers in a temperature and humidity-controlled environment. The dehumidification system does not detrimentally affect the fiber&#39;s properties (e.g., strength) by evenly drying the fibers and not subjecting the fibers to repeated high temperature environments, allowing the fibers to be used in more biocomposite applications, such as a reinforcement material. Also the dehumidification method reduces/prevents fiber discoloration, odor, and decomposition.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Patent Application Ser. No. 61/948,863, filed on Mar. 6, 2014, the entirety of which is expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The subject matter disclosed herein relates generally to biocomposite materials and, in particular, to a method and system or apparatus for the dehumidification of fibrous materials for use in the manufacture of biocomposite materials. 
       BACKGROUND OF THE INVENTION 
       [0003]    Fibrous materials such as straw from flax, sisal, hemp, jute and coir, banana, among others, are used in the formation of biocomposite materials, where the fibrous material is combined with another compound, such as a polymer. The fibrous materials can be in the form of raw fibrous materials, or fibers selected from the components of the raw fibrous material, such as the cellulose fibers once separated from the hemicelluloses, lignin and impurities components of the raw fibrous materials. During the preparation and/or processing of the fibers/fibrous materials, these materials are often dried to remove the moisture in the fibrous materials to allow for better processing of the fibrous materials into the biocomposite compositions. Systems and methods that traditionally have and currently are used to dry fibers include: oven drying, microwave drying, microwave-convection drying, microwave-vacuum drying, thin layer drying, among others. 
         [0004]    In particular, these traditional and current fiber drying processes, such as oven drying and thin layer drying, the fibers or fibrous materials are placed in enclosures that utilize high temperatures to evaporate moisture from the fibers, which are laid out in a thin layer within the enclosure. This wastes energy and space, disturbs and/or causes damage to the fibers molecular structure, and does not evenly dry the fibers. The prior art drying systems and methods thus negatively affect the fiber&#39;s properties, e.g. strength, thereby degrading the fibers usefulness and making them not suited for reinforcement applications in biocomposite materials. Also, the prior art drying systems and methods cause fiber discoloration, the formation of odors in the fibrous materials, and the decomposition of the fibrous materials, all of which are highly undesirable for fibers to be utilized in biocomposite material products. 
         [0005]    As a result, a system and method for drying fibers and/or fibrous materials that will not negatively affect the molecular structure of the fibers or fibrous materials, yet provides even and efficient drying of the fibers, is needed. 
       SUMMARY OF THE INVENTION 
       [0006]    According to one aspect of an exemplary embodiment of the present disclosure, a system or apparatus and method is provided for drying for fibers or fibrous materials, such as flax, hemp, jute, sisal, and coir, among others by dehumidifying the fibers in a temperature and humidity-controlled environment. The dehumidification system does not detrimentally affect the fiber&#39;s properties (e,g., strength) by evenly drying the fibers and not subjecting the fibers to repeated high temperature environments or conditions, allowing the fibers to be effectively used in more biocomposite applications, such as a reinforcement material. Also, the dehumidification method reduces/prevents fiber discoloration, odor, and decomposition of the fibers. 
         [0007]    According to another aspect of an exemplary embodiment of the present disclosure, the system and method does not waste energy and space, and evenly dries the fibers. 
         [0008]    These and other objects, advantages, and features of the invention will become apparent to those skilled in the art from the detailed description and the accompanying drawings. It should be understood, however, that the detailed description and accompanying drawings, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]    The drawings furnished herewith illustrate a preferred construction of the present invention in which the above advantages and features are clearly disclosed as well as others which will be readily understood from the following description of the illustrated embodiment. 
           [0010]    In the drawings: 
           [0011]      FIG. 1  is a perspective view of an exemplary embodiment of a dehumidification system or apparatus constructed according to the present disclosure; 
           [0012]      FIG. 2  is a front perspective view of the system of  FIG. 1 ; 
           [0013]      FIG. 3  is a partially broken away perspective view of the interior of the system of  FIG. 1 ; and 
           [0014]      FIG. 4  is a schematic view of the interior of the system of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    With reference now to the drawing figure in which like reference numerals designate like parts throughout the disclosure, an exemplary embodiment of a system or apparatus provided for drying various types of fibers and/or fibrous materials in order for use of the fibers/fibrous material in a biocomposite material is illustrated generally at  10  in  FIG. 1 . This system and method is related to the processes disclosed in co-owned and co-pending U.S. patent application Ser. No. 14/087,326, filed on Nov. 22, 2013, the entirety of which is expressly incorporated by reference herein. 
         [0016]    In the illustrated embodiment, the system  10  includes a cabinet  12  formed of any suitable type of material, such as a metal or plastic material. The cabinet  12  includes an insulated enclosure  14  that defines an interior  16 . The interior  16  is accessed using a pair of doors  18  that are pivotally or otherwise movably connected to the enclosure  14 , though any number of doors  18  can be utilized as desired. A sealing member  20  is optionally disposed on the enclosure  14  around the interior  16  or on the periphery of the doors  18  in order to be engaged between the enclosure  14  and the doors  18  when the doors  18  are in a closed position to effectively seal off the insulated interior  16  of the cabinet  12  from the exterior environment when the doors  18  are closed. 
         [0017]    Looking now at  FIGS. 2-4 , the interior  16  of the cabinet  14  includes a number of compartments, in the illustrated exemplary embodiment being first compartment  22 , second compartment  24 , and third compartment  26 , that are defined m the illustrated embodiment by partition walls  28  extending across the interior  16  of the enclosure  14 . The first compartment  22  and third compartment  26  are each formed with a rack system  30  or similar supporting structure therein. The rack system  30  enables a number of trays or shelves  32  to be positioned within each compartment  22  and  26  in a spaced configuration across the substantially the entire volume of the compartments  22 , 26 . The rack system  30  can be designed to enable the shelves  32  to be slid inwardly and outwardly relative to the compartments  22 , 26  on tracks  34 , or can be formed as stationary shelves  32  that are immobile, among other design alternatives. In addition, the shelves  32  can be formed as simple flat surfaces, or as in the illustrated exemplary embodiment, can be formed as baskets  36  having a bottom surface  38  and a number of upwardly extending side surfaces  40  that extend above the bottom surface  38 . The side surfaces  40  adjacent the partition walls  28  can include suitable structures, such as flanges  41 , that are slidably engaged within the tracks  34  to enable the shelves  32  to move with respect to the tracks  34 . 
         [0018]    Each of the bottom surface  38  and side surfaces  40 , or at least the bottom surface  38 , is formed as a mesh, perforated or open screen-like material in the illustrated exemplary embodiment. This configuration enables the shelves  32  to hold a fibrous material thereon, while also allowing for air flow through the bottom surface  38  and side surfaces  40  to more effectively contact the fibrous material on the shelves  32 . In addition, the bottom surface  38  of the trays or shelves  32  can include a channel  43  or spaced lower surface (not shown) disposed below the bottom surface  38  for collection of the water removed from the fibers that passed downwardly through the bottom surface  38  of the shelves  32 . The channel  43  can subsequently direct the water collected therein from the tray  32 , such as to one side of the enclosure  22 , 26 , where the water can pass directly to a bottom water collection tray or the bottom surface  47  of the compartment  22 , 26  for removal of the water from within the enclosure, resulting in faster drying of the fibers. 
         [0019]    In one exemplary embodiment, the bottom surface  38  is formed with square apertures approximately 1 cm×1 cm in size to assist in air circulation around and through the fibers on the trays  32 , and to enable moisture or water to flow through the apertures while holding the fibers/fibrous materials on the upper surface of the bottom surface  38  of the tray  32 . Further, in another exemplary embodiment, the trays  32  can be inclined within the compartments  22 , 26 , such as at a 5 degree angle relative to the horizontal orientation of the cabinet  12 , e.g., such that the rear of the shelf  32  is higher than the front of the shelf  32  near the door  18 , to further facilitate the flow of collected water through the channels  43  on the trays  26  to the water collection tray  47  without affecting the ability to dry the fibers. 
         [0020]    As best shown in  FIGS. 3 and 4 , in another exemplary embodiment the second compartment  24  is disposed between the first compartment  22  and third compartment  26 , and includes disposed therein a number of heaters  42 , a number of commercial or industrial dehumidifiers  44 , a pair of relative humidity sensors  46  and a pair of thermocouples  48 , though the sensors  46  and thermocouples  48  could also be disposed one in each of the compartments  22  and  26 . The heater  42  is operable by a suitable power source, such as power outlet  50  operably connected to a conventional residential or commercial power supply, and includes a controller  52  operably connected to the heater  42  in a manner to operate the heater(s)  42  to supply heated air to each of the compartments  22  and  26  through a suitable conduit operably connected between the heater  42  and the first compartment  22  and third compartment  26 , which are sealed off from the second compartment  24  by the walls  28  and the seal members  20  disposed around the first and third compartments  22  and  26 , either on the enclosure or on the doors  18 . The dehumidifiers  44  are also operable by a suitable power source, such as power outlet  50 , and the controller  52  also operably connected to the dehumidifiers  44  in a manner to withdraw moisture from each of the first and third compartments  22  and  26  through a suitable conduit  55  operably connected between the dehumidifiers  44  and the first and third compartments  22  and  26 . The controller  52  can be operably connected to the sensors  46  and the thermocouples  48 , as well as the heater(s)  42  and dehumidifier(s)  44  either by direct wired or wireless connection. 
         [0021]    In one exemplary embodiment of the method of operation of the apparatus  10 , the fibrous material, whether raw fibrous material or a pre-processed form or component thereof, is placed on the shelves  32  in one or both of the first and third compartments  22  and  26 . The doors  18  are closed in order to seal off the first and third compartments  22  and  26  from the exterior environment, and the heater(s)  42  and dehumidifier(s)  44  are operated using the controller  46 . The heater(s)  42  and dehumidifier(s)  44  remain shut-off in order to maintain the fibrous material on the shelves  32  at room temperature until the moisture content reaches an equilibrium level, as determined or measured by the sensors  46  and/or thermocouples  48  operably connected to the controller  52  to illustrate the current conditions within the respective compartments  22  and  26 . Alternatively, the fibrous material can remain outside of the compartments  22  and  26  until the moisture content reaches equilibrium, at which time the material can be placed on the shelves  32 , The doors  18  of the cabinet  12  are then closed, and the dehumidifier(s)  44  are turned on via the controller  52 . The temperature in the respective compartments  22  and  26  of the cabinet  12  is increased slightly from room temperature around 35° C.-50° C.) by operating the heater(s)  42  using the controller  52 , but not high enough to damage the fiber as in prior art drying systems. 
         [0022]    Thermocouples  48  and relative humidity sensors  46  monitor the air temperature and humidity inside the compartments  22  and  26  of the cabinet  12  during this time, such that the operation of the heater(s)  42  and the dehumidifier(s)  44  can be adjusted, if necessary. The combination of increased temperature and dehumidification evenly dries the fibers to the desired moisture content, which can be selected as desired, but in one embodiment is below 2% by weight. Further, as water or moisture is taken out of the sealed environments in each compartment  22  and  26 , the associated dehumidifier  44  directs or empties that water into a container or drain (not shown) disposed at or in the back of the compartment  24  of the cabinet  12 . 
         [0023]    As a result of the drying of the fibrous material using lower heat than prior art methods coupled with dehumidification, it is possible to hold/improve the strength and quality of the fibers or fibrous materials by not damaging the molecular and/or internal structure of the fiber/fibrous materials, thereby allowing the fiber/fibrous material to perform more functions and be used in more biocomposite applications, and to achieve a consistent moisture content across all fibers, as the present system and method does not dehydrate the fibers. The present system  10  and method is an inexpensive drying method with reduced energy consumption and no resulting fiber discoloration, that also reduces and/or prevents fiber odor and the decomposition of the washed fiber during dehumidification. The system  10  and associated method also eliminates exposure of the fibers or fibrous materials to high temperatures before the biocomposite manufacturing stage, as the present dehumidification drying method reduces the number of times the fiber is exposed to high temperatures such that the fibers experience high temperatures only during the biocomposite manufacturing, instead of during the fiber processing (from traditional drying methods) and the biocomposite manufacturing. The system  10  and associated method also has minimal space requirements, and makes it easier to handle and further process the fibers after dehumidification than after traditional methods. as the fibers comes out fluffy and smooth, with no shrinking or binding to each other. Additionally, the system  10  and process is safe and easy to operate on all types of fibers, including flax, hemp, jute, sisal, and coir, among others, and provides complete and close control of the temperature and humidity of the dehumidifying environment within the compartments  22  and  26  to achieve these results. 
         [0024]    It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.