Patent Publication Number: US-2010112326-A1

Title: Compound material member and the manufacturing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 097142324 filed in Taiwan, Republic of China on Nov. 13, 2008, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a composite material member and a method for manufacturing the same and, more particularly, to a composite material member manufactured by integrally combining rubber and composite fiber and a method for manufacturing the same. 
     2. Description of the Related Art 
     In the past, casings of different kinds of electronic devices mainly have a design with a smooth appearance. In recent years, with development of the electronic device, certain casings have advanced touch, such as casings of notebook computers made of skin or bamboo to improve commodity value of the electronic devices and purchase desires of consumers. 
     Fiber reinforced plastic (FRP) is an insulating material generally used for a printed circuit board, and it belongs to a composite fiber material. The fiber structure of FRP can suffer greater tension, and the resin can suffer greater shearing force; and further, a surface of a casing may present special vision feeling as if a clothbound ancient book to greatly improve value and quality of an electronic device. 
     According to the aforementioned, if the composite fiber is used to form a casing, the casing can suffer greater external stress and is beneficial for a slim design of an electronic device, On the other hand, the composite fiber is also light to being beneficial for a light, slim, short, and small design of the electronic device. In addition, if the glass fiber is replaced with carbon fiber, the casing may further have an electromagnetic protection effect. Other composite fiber, such as Kevlar fiber, can also increase functionality of the casing of the electronic device according to characteristic of the material. 
     The characteristic of the composite fiber is different from that of plastic and an iron material (such as a metal material). When an element made of another material such as rubber is to be assembled to an inner side of the casing made of the plastic, the plastic casing can fix the element by wrapping the plastic around the element, or positioning ribs can be formed at the plastic casing to help assembling the element. If the casing is made of the iron material, a hole can be punched on the iron casing for assembling the element, or the element can be directly riveted to the iron casing. However, the above assembling method is not suitable for the casing made of the composite fiber. 
     In a practical application, a rubber element made of rubber should be fixed on an inner side of a casing to satisfy cushioning or positioning or other needs. However, if the rubber element is to be assembled to a surface of the casing made of the composite fiber, only glue or twin adhesive is used. 
     However, the method for assembling via the glue or the twin adhesive has a plurality of steps and higher costs and manpower; and further, since the rubber is elastic and is deformed easily, the strength and reliability is lower when the general glue or the twin adhesive is used. If the glue or the twin adhesive made of special silica gel is used, many negative effects on commercialized manufacture are happened as a result of the higher cost. 
     BRIEF SUMMARY OF THE INVENTION 
     One objective of this invention is to provide a composite material member manufactured by integrally combining rubber and composite fiber and a method for manufacturing the same to improve the prior art. 
     One objective of the invention is to provide a composite material member manufactured by integrally combining fiber and rubber and a method for manufacturing the same. According to this method, a mold is used to manufacture the composite material member. The mold includes a first mold and a second mold having a cavity. The method includes the following steps. 
     First, a composite fiber element is disposed in the first mold. The composite fiber element may be thermosetting or not, and the composite fiber element is a structure of at least one fiber layer wrapped in resin. The first mold and the second mold are then closed. Finally, the cavity is filled with rubber. Different forming environments are provided according to whether the composite fiber element is thermosetting or not thus to form and fix a rubber element on the resin of the composite fiber element. 
     Another objective of the invention is to provide a composite material member. The composite material member includes a composite fiber element and a rubber element. The composite fiber element includes at least one fiber layer and resin wrapping the fiber layer. The rubber element is directly formed and fixed on the resin of the composite fiber element. 
     According to the composite material member and the method for manufacturing the same in this invention, the fiber and the rubber can be integrally combined to form the composite material member in cooperation with the mold and the forming steps. Thus, the composite material member has a surface with special touch, and the composite material member has powerful shearing resistance and tension resistance; and further, the composite material member is light and slim to being suitable for a light, slim, short, and small design of a commodity. Proper strength and reliability can be provided by combining the rubber and the composite fiber via the method in the invention. Combining processes can be further simplified to reduce consumption of accessory materials. 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial exploded diagram showing a notebook computer according to one embodiment of the invention; 
         FIG. 2  is a side sectional schematic diagram showing a composite material member according to one embodiment of the invention; 
         FIG. 3  is a flow chart showing a method for manufacturing a composite material member according to one embodiment of the invention; 
         FIG. 4  is a schematic diagram showing a state corresponding to step S 04  in  FIG. 3  according to one embodiment of the invention; 
         FIG. 5  is a flow chart showing a first fixing mode according to one embodiment of the invention; 
         FIG. 6  is a flow chart showing a second fixing mode according to one embodiment of the invention; and 
         FIG. 7  is a schematic diagram showing a composite material member according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a partial exploded diagram showing a notebook computer  10  according to one embodiment of the invention. Please refer to  FIG. 1 . In one preferred embodiment of the invention, a composite material member  30  can be applied to a casing  20  of a commodity. The commodity may be a notebook computer  10 , a liquid crystal display, an intelligent mobile phone, or other electronic commodities, and it may also be a packing box, furniture, or other non-electronic commodities. The composite material member  30  is suitable to be a main portion of the casing  20 . 
     In  FIG. 1 , an upper cover with a liquid crystal panel  22  of the notebook computer  10  is taken for example to describe application of the composite material member  30 . The composite material member  30  includes a composite fiber element  32  and a rubber element  34  which are integrally formed. One side of the composite fiber element  32  different from the rubber element  34  is suitable to be a surface of the casing  20 . Thus, the appearance presents special texture and vision feeling as if a clothbound ancient book. The rubber element  34  is disposed in an inner side of the casing  20  to be used as a buffer of the liquid crystal panel  22  and the rubber element  34  also provides an effect upon shock absorbing and positioning. 
       FIG. 2  is a side sectional schematic diagram showing the composite material member  30  according to one embodiment of the invention. Please refer to  FIG. 2  the composite material member  30  includes a composite fiber element  32  and a rubber element  34 . The composite fiber element  32  includes at least one fiber layer  3204  and resin  3202  wrapping the fiber layer  3204 . In the enlarged section in  FIG. 2 , the composite fiber element  32  has six fiber layers  3204 . 
     In generally, the fiber layer  3204  is a fabric. The fiber layer  3204  may be made of carbon fiber (CF), glass fiber, or Kevlar fiber and so on. The casing  20  may have an electromagnetic interference (EMI) prevention effect as the composite fiber element  32  is made of carbon fiber. The carbon fiber is further resistant to a high temperature above 1000° C. to simplify the manufacture. 
     In addition, the rubber element  34  is directly formed and fixed on the resin  3202 . Thus, the appearance is that one rubber element  34  is fixed to a surface of the composite fiber element  32  to become an integral composite material member  30 . If silicon rubber is used, a curing temperature is about in the range of 165-190° C. If neutral rubber is used, the curing temperature is about 150° C. 
       FIG. 3  is a flow chart showing a method for manufacturing a composite material member according to one embodiment of the invention. According to the method for manufacturing the composite material member  30 , a mold  40  is used. The mold  40  includes a first mold  42  and a second mold  44 , and the second mold  44  has a cavity  4402 . The structure of the mold  40  and the composite material member  30  is described in detail in  FIG. 4 . The method includes the following steps. 
     Step S 02 : disposing a composite fiber element  32  in the first mold  42 . The first mold  42  has a containing space for just containing the composite fiber element  32 . The composite fiber element  32  is a structure of at least one fiber layer  3204  wrapped with resin  3202 . 
     In this step, the composite fiber element  32  may be thermosetting or not. One surface of the composite fiber element  32  which is to be an outer surface of the casing  20  is located at the bottom surface of the containing space. The surface of the composite fiber element  32  which is exposed upward and used to combine the rubber element  34  is to be an inner surface of the casing  20 . 
     Step S 04 : closing the first mold  42  and the second mold  44 . 
     Step S 06 : filling the cavity  4402  with rubber to form and fix a rubber element  34  on the resin  3202  of the composite fiber element  32 . 
       FIG. 4  is a schematic diagram showing a state corresponding to step S 04  in  FIG. 3  according to the embodiment of the invention. Please refer to  FIG. 4  in cooperation with  FIG. 3 . The mold  40  is formed by stacking the second mold  44  and the first mold  42 . The second mold  44  has the cavity  4402 , and the cavity  4402  is communicated with outside via a runner  4404 . The molten rubber flows from outside to the cavity  4402  via the runner  4404 . The composite fiber element  32  is disposed in the first mold  42 . 
     Furthermore, regarding the method for forming the rubber element  34 , the rubber can be used to form the rubber element  34  through an injection mode wherein the step of closing the first mold  42  and the second mold  44  is to allow the opening of the cavity  4402  to face and to be attached to a surface of the composite fiber element  32 , or through a hot-pressing mode. Besides, the step of filling the cavity  4402  with rubber can be adjusted to perform before the step of closing the first mold  42  and the second mold  44  according to the method of forming the rubber element  34 . 
     The aforementioned formed composite material member  30  is a part of the casing  20  of a device, and the surface which is opposite to a surface of the composite fiber element  32  connecting the rubber element  34  is an external surface of the device. The special touch can improve commodity value of the device and purchase desires of consumers. 
     How to form and fix the rubber element  34  on the resin  3202  is described in detail hereinbelow. There are two fixing modes to allow the rubber element  34  to be directly formed and fixed on the resin  3202 . In a first mode, an attached mode is used in a first forming environment. In a second mode, a fused mode is used in a second forming environment. 
     The first and second fixing modes are described in  FIG. 5  and  FIG. 6 , respectively.  FIG. 5  is a flow chart showing a first fixing mode according to one embodiment of the invention. The fixing mode in  FIG. 5  further includes the following steps. 
     Step S 12 : stacking a plurality of layers of fabrics shaped by cutting according to the strength or the thickness of the casing  20  is needed. 
     Step S 14 : immersing the fabrics into resin  3202 . The resin  3202  is used as adhesives between the respective layers of the fabric to form the composite fiber element  32 ; and further, the composite fiber element  32  is not thermosetting. 
     Step S 16 : performing a thermosetting process to the composite fiber element  32  and allowing the composite fiber element  32  to form the thermosetting composite fiber element  32 . 
     According to the above, the rubber element  34  is formed in a first forming environment and the rubber element  34  is fixed on the resin  3202  of the thermosetting composite fiber element  32  in an attached mode. 
     When the first mode is used, since the composite fiber is thermosetting, only a thermal change of the rubber needs to be considered. That is, only the curing temperature of the rubber needs to be considered. Thus, the needed temperature of the first forming environment is estimated to be about between 0 and 200□, the pressure is about between 0 and 200 kgf, and the manufacturing time does not exceed 300 seconds. However, the needed manufacturing parameters are different according to different kinds of the rubber. 
       FIG. 6  is a flow chart showing a second fixing mode according to one embodiment of the invention. Please refer to  FIG. 6 . A fused mode in  FIG. 6  includes the following steps. 
     Step S 22 : stacking a plurality of layers of fabrics shaped by cutting according to the strength or the thickness of the casing  20  is needed. 
     Step S 24 : immersing the fabrics into resin  3202 . The resin  3202  is used as adhesives between the respective layers of the fabric to form the composite fiber element  32  which is not thermosetting. 
     Step S 26 : forming the rubber element  34  in a second forming environment and fixing the rubber element  34  on the resin  3202  of the composite fiber element  32  which is not thermosetting in the fused mode. 
     Step S 28 : performing a thermosetting process to allow the resin of the composite fiber element  32  which is not thermosetting and the rubber to be thermosetting. In this stage, the composite fiber element  32  can form the thermosetting composite fiber element  32 . 
     When the second fixing mode is used, the composite material is not thermosetting. In this process, the thermal changes of the rubber and the resin  3202  need to be considered at the same time. Therefore, the needed temperature of the second forming environment is estimated to be about between 0 and 250□, the pressure is about between 0 and 500 kgf, and the manufacturing time does not exceed 90 minutes. However, the needed manufacturing parameters are also different according to different kinds of the rubber. 
       FIG. 7  is a schematic diagram showing a composite material member  30  according to another embodiment of the invention. For certain manufacture processes or products, to prevent the pressure and temperature at which the rubber element  34  is formed from damaging a surface of the resin  3202  when the rubber element  34  is fixed on a surface of the composite fiber element  32 , the aforementioned method further includes the following steps after the composite fiber element  32  is disposed in the first mold  42  and before the rubber element  34  is formed and fixed. 
     A buffer material  36  is disposed at a surface of the resin  3202  where the rubber element  34  is to be formed and fixed. And then, the buffer material  36  can ease the heat and pressure generated when the rubber element  34  is formed, thus to prevent the surface of the resin  3202  of the formed composite fiber element  32  from being damaged seriously. 
     The buffer material  36  may be made of aluminum alloy, copper alloy, or Mylar. 
     According to the aforementioned, the fiber and the rubber can be integrally combined to form the composite material member  30  via the composite material member  30  and the method for manufacturing the composite material member  30  in the embodiment of the invention, in cooperation with the mold  40  and the forming steps. Thereby, the composite material member  30  has a surface with special touch, and the composite material member has powerful shearing resistance and tension resistance; and further, the composite material member  30  is light and slim to being suitable for a light, slim, short, and small design of a commodity. In the present invention, proper strength and reliability can be provided by combining the rubber and the composite fiber; moreover, combining processes can be simplified to reduce consumption of accessory materials. 
     Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope of the invention. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope and spirit of the invention. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.