Abstract:
The present invention relates to a modular conveyor belt formed of a plurality of interconnected modules with at least one of them having an antimicorbial material associated therewith. This provides the belt being resistant to growth of fungus, yeast, viruses, and Gram-positive and Gram-negative bacteria including Staph,  E coli  Klebsiella and Salmonella.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to beltings and, more particularly, to a module for a modular conveyor belt. The module preferably includes a broad spectrum antimicrobial material associated therewith to inhibit bacterial growth and promote asepsis on the belting.  
           [0003]    2. Prior Art  
           [0004]    Modular conveyor belting is well-know. For quality control purposes in the food industry, it is desirable that the conveyor belt is readily inspected to assure cleanliness. Government and industry regulations also specify standards of inspection and cleanliness for equipment used in processing products for human consumption. There is, therefore, a need for a conveyor belt having associated therewith an antimicrobial material that inhibits bacterial growth and promotes asepsis on the belting through extended wear, and that is safe for human contact. The antimicrobial material needs to be free of carcinogenic substances and any agents that are both harmful to the environment and are not suitable for human ingestion. As will be explained in detail presently, the conveyor belting of the present invention having the antimicrobial material associated therewith meets these criteria.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention relates to a modular conveyor belting having antimicrobial characteristics that inhibit bacterial growth and promote asepsis on the belting, which comprises: a plurality of like modules, each module comprised of a polymeric material and including a first plurality of link ends, a second plurality of link ends and an intermediate section integrally formed with and joining the first and second plurality of link ends, wherein the link ends of each of the modules are releasably engaged between link ends of an adjacent module except for individual link ends disposed at the extreme sides of the module; a pivot rod for pivotally connecting the modules at engaged link ends, wherein the link ends of each of the modules are of a width somewhat less than the spacing between confronting link ends along the pivotal axis thereof to provide for pivotal connection of the modules; and an antimicrobial material associated with the modules, wherein the antimicrobial material is selected from the group consisting of Ca(OH) 2 , MgO, ZnO, Al 2 O 3 , CuO, silver, zinc pyrithione, methyl-N-(2-benzimidazoloyl)carbamat, N-butylbenso-thiazolinone, 10′10-oxybisphenoxyarsin, tebuconazole, imidazole, silver-sodium hydrogen zirconium phosphate, and mixtures thereof provided as a topical applicant to an exposed surface of the module or incorporated into the polymeric material thereof.  
           [0006]    Further, the present invention relates to a method for manufacturing a modular conveyor belt having antimicrobial characteristics that inhibit bacterial growth and promote asepsis on the belting, which comprises: providing a plurality of like modules, each comprising a polymeric material and including a first plurality of link ends, a second plurality of link ends and an intermediate section integrally formed with and joining the first and second plurality of link ends, wherein the link ends of each of the modules are releasably engaged between link ends of an adjacent module except for individual link ends disposed at the extreme sides of the module; providing a pivot rod for pivotally connecting the modules at engaged link ends, wherein the link ends of each of the modules are of a width somewhat less than the spacing between confronting link ends along the pivotal axis thereof to provide for pivotal connection of the modules; and associating an antimicrobial material selected from the group consisting of Ca(OH) 2 , MgO, ZnO, Al 2 O 3 , CuO, silver, zinc pyrithione, methyl-N-(2-benzimidazoloyl)-carbamat, N-butylbenso-thiazolinone, 10′10-oxybisphenoxyarsin, tebuconazole, imidazole, silver-sodium hydrogen zirconium phosphate, and mixtures thereof with the modules as a topical applicant to an exposed surface thereof or incorporated into the polymeric material thereof.  
           [0007]    Thus, it is within the scope of the present invention that a modular conveyor belt is formed of a plurality of interconnected modules with at least one of them having an antimicorbial material associated therewith. This provides the belt being resistant to growth of fungus, yeast, viruses, and Gram-positive and Gram-negative bacteria including Staph,  E coli  Klebsiella and Salmonella. The preferred method of associating the antimicrobial material with the modules is to incorporate it into the synthetic polymeric master batch prior to forming them. In that respect, the antimicrobial material in powder form is added as a component to the mixture comprising the synthetic polymeric material and preferably comprises, by weight, from about 0.05% to about 10.0%, and preferably from about 0.1% to about 5.0%, and more preferably from about 0.5% to about 2.0% of the synthetic polymer into which it is incorporated. The resulting synthetic polymeric admixture is injection molded or formed by another molding process to provide modules of various shaped and functions including radius modules, flat top modules, flush grid modules, raised rib modules and flight modules.  
           [0008]    It is within the scope of the present invention that other components of a modular belt including the pivot rods, sprockets, fingerboards and side guards are provided with the present antimicrobial materials to inhibit bacterial growth and promote asepsis thereon.  
           [0009]    The antimicrobial materials incorporated into a belting components according to the present invention can withstand temperatures of up to about 350° F. without losing its biocidal and biostatic properties.  
           [0010]    These and other aspects of the present invention will become more apparent to those of ordinary skill in the art by reference to the following description and to the appended drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a plan view of a modular conveyor belt  12  constructed of a plurality of interconnected radius modules  10  having an antimicrobial material associated therewith according to the present invention.  
         [0012]    [0012]FIG. 2 is an upside down, side elevational view of the modular conveyor belt  12  shown in FIG. 1.  
         [0013]    [0013]FIG. 3 is a perspective view of the module  10  comprising the conveyor belt  12  shown in FIG. 1.  
         [0014]    [0014]FIG. 4 is an upside down perspective view of the module  10  shown in FIG. 3.  
         [0015]    [0015]FIG. 5 is a cross-sectional view of an exemplary flat top module  100  constructed having a core  102  completely surrounded by a skin  104  having an antimicrobial material associated therewith according to another embodiment of the present invention.  
         [0016]    [0016]FIG. 6 is a plan view of the flat top module  100  shown in FIG. 5. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    Referring now to the drawings, FIGS.  1  to  4  show an exemplary radius module  10  according to one embodiment of the present invention. The radius module  10  preferably includes a broad spectrum antimicrobial material associated therewith to inhibit bacterial growth and promote asepsis thereon. In use, a plurality of modules  10  are interconnected together to form a modular linked conveyor belt  12  which may be conveyed in either direction and which is particularly suited for traveling along both straight and curved paths.  
         [0018]    Each module  10  is an integral unitary structure of polymeric material formed in an injection molding or other molding process and preferably having the antimicrobial material associated therewith. The antimicrobial material is selected from the group consisting of Ca(OH) 2 , MgO, ZnO, Al 2 O 3 , CuO, silver, zinc pyrithione, methyl-N-(2-benzimidazoloyl)-carbamat, N-butylbenso-thiazolinone, 10′10-oxybisphenoxyarsin, tebuconazole, imidazole, silver-sodium hydrogen zirconium phosphate, and mixtures thereof. Suitable polymeric materials include polyethylene, polypropylene homopolymer or copolymer, POM and ABS. The concentration of the antimicrobial material in the polymeric material preferably varies from about 0.05% to about 10.0%, by weight. Having the antimicrobial material associated with the module means that it is provided as a topical applicant to an exposed surface thereof, or the antimicrobial material is incorporated into the polymeric material master batch prior to the molding process. In the former case, the belt is run through a bath comprising the antimicrobial material or the antimicrobial material is sprayed thereon.  
         [0019]    The radius module  10  includes an intermediate section  14  supporting a plurality of first link ends  16  and a plurality of second link ends  18 . The first link ends  16  are disposed in the direction of belt travel indicated by arrow  20  and the plurality of second link ends  18  extend in the opposite direction. The intermediate section  14  is comprised of an upper, transverse stiffening web  22  forming into a lower corrugated portion  24 . The corrugated portion  24  forms a series of ridges  26  and valleys  28  in a sinusoidal manner. Along with the transverse web  22  of the intermediate section  14 , the ridges  26  extending toward the left of FIG. 2 support the first link ends  16  while the ridges  26  extending toward the right in the drawing support the second link ends  18 .  
         [0020]    The first link ends  16  include a leg portion  30  extending to a distal head portion  32 . Likewise, the second link ends  18  include a leg portion  34  extending to a distal head portion  36 . An opening  38  is defined between spaced apart leg portions  30  and distal head portions  32  of adjacent first link ends  16 . Similarly, an opening  40  is defined between spaced apart leg portions  34  and head portions  36  of adjacent second link ends  18 . The openings  38  and  40  terminate in the multilevel surface defined by the web  22  and corrugated portion  24  of the intermediate section  14 .  
         [0021]    In that respect, the second link ends  18  have the same overall shape as the first link ends  16  (except for the last link end  42 ) and are designed to fit into the openings  38  between the first link ends  16  such that adjacent belt modules can be intercalated and pivotally connected by pivot rods  44 . Similarly, the first link ends  16  are shaped to fit into the openings  40  between the second link ends  18  to provide for intercalation of pivotally connected modules  10 . The pivot rods are typically made of a similar or of a compatible polymeric material as that comprising the modules.  
         [0022]    The top level of the multi-level intermediate section  14  (best shown in FIG. 1) is defined by a wall  46  of the web  22 . The corners where the side walls of the respective first and second link ends  16 ,  18  meet the web wall  46  are radiused to be smooth and to protect the conveyed product from damage. The relatively thin corrugated portion  24  has a pair of essentially parallel side walls  48 ,  50  forming the regularly spaced alternating ridges  26  and valleys  28  of the intermediate section  14 .  
         [0023]    As shown in FIG. 4, the first link ends  16  each include a slot  52  disposed there through transverse to the direction of belt travel. The slot  52  extends in the direction of belt travel such that it is generally oblong and receives the pivot rod  44 . The second link ends each have a transverse opening  54  disposed there through. In that manner, the pivot rod  44  passes through the slots  52  in the first link ends  16  and through the openings  54  in the second link ends  16  of intercalated modules forming the belt  12  (FIG. 1). The openings  54  correspond to the shape of the pivot rod  44  so that, in contrast to the slots  52 , the pivot rod  44  preferably cannot move in the direction of belt travel inside them. However, due to the oblong shape of the slots  52 , the pivot rod  44  pivots inside them such that the intercalated modules are capable of collapsing on one side of the belt while the other side fans out due to the nesting of the link ends  16 ,  18  and cooperating spaces in the adjacent belt modules.  
         [0024]    The last link end  42  of the belt module  10  includes a second opening  56  disposed around opening  54  to provide for countersinking a head (not shown) at the end of the pivot rod  44 .  
         [0025]    The heads  32  and  36  of the respective first and second link ends  16 ,  18  are radiused in a smooth rounded surfaces  58 ,  60 . The rounded surfaces  58 ,  60  preferably have a constant radius and provide a driving surface for engagement with a drive sprocket (not shown), as described in U.S. Pat. No. 6,330,941 to Guldenfels, which is assigned to the assignee of the present invention and incorporated herein by reference.  
         [0026]    Also, the rounded surfaces  58 ,  60  of the link ends  16 ,  18  enables them to extend under the web  22  into the space defined by the corrugated portion  24 . In this manner, the web  22  partially hoods the link ends when the belt  12  collapses. Accordingly, the belt module  10  has the web  22  for structural stability while the corrugated portion  24  provides recesses for collapsing the belt modules along a curved path of a relatively tight radius.  
         [0027]    [0027]FIGS. 5 and 6 show another embodiment of a module constructed according to the present invention. This module is referred to as a flat top module  100  and also has an antimicrobial material associated therewith. The flat top module  100  has a sandwich layer construction comprising a core portion  102  surrounded and substantially encased by a skin portion  104 . Preferably, the polymeric material comprising the skin portion  104  contains an antimicrobial material selected from the group consisting of Ca(OH) 2 , MgO, ZnO, Al 2 O 3 , CuO, silver, zinc pyrithione, methyl-N-(2-benzimidazoloyl)-carbamat, N-butylbenso-thiazolinone, 10′10-oxybisphenoxyarsin, tebuconazole, imidazole, silver-sodium hydrogen zirconium phosphate, and mixtures thereof. The concentration of the antimicrobial material in the polymeric material of the skin portion  104  preferably varies from about 0.05% to about 10.0%, by weight. The polymeric material of the core portion  102  preferably contains little if any of the antimicrobial material. If the core portion  102  does contain antimicrobial material, its concentration is preferably less than that of the skin portion  104 . Otherwise, the polymeric materials for the core and skin portions can be the same or different. Suitable polymeric materials include polyethylene, polypropylene homopolymer or copolymer, POM and ABS. The sandwich layer construction is preferably provided by a molding process or method, as described in U.S. application Ser. No. 09/867,122, filed May 29, 2001, which is assigned to the assignee of the present invention and incorporated herein by reference.  
         [0028]    In that respect, the sandwich constructed flat top module  100  includes a generally rectangular plate-like body  106  having a first plurality of link ends  108  and a second plurality of link ends  110  extending in opposite directions therefrom. A transverse rib  112  extends across the width of the underside of the body  106  to form opposed channels  114  and  116  terminating at the respective link ends  108  and  110 . The rib  112  and the inside of the link ends  108 ,  110  are adapted to mate with corresponding sprocket teeth of a sprocket wheel (not shown) to impart a driving force to a conveyor belt formed by interconnecting a plurality of the modules  100  in a similar manner as previously described with respect to the radius module  10  and its belt  12 . The under structure of the module  100  formed by the transverse rib  112  serves to strengthen the module and prevent any significant binding about its longitudinal or transverse axis.  
         [0029]    The link ends  108  and  110  circumscribe corresponding aligned cylindrically shaped transverse openings  118 . The openings  118  receive pivot rods (not shown) adapted to pivotally connect a plurality of the modules in an end to end configuration to form a modular conveyor belt (not shown) similar to the conveyor belt  12  shown in FIGS. 1 and 2. Preferably, the modules  100  are end-to-end reversible so that either end of a first module can mate with either end of a second module.  
         [0030]    While the present invention has been particularly described with respect to a radius module and a flat top module, it is not intended to be so limited. Those skilled in the art will recognize that the present antimicrobial materials are readily incorporable into other types of modules and belt components. These include the modules described in U.S. Pat. No. 6,305,530 to Guldenfels, U.S. Pat. No. 6,357,581 to Guldenfels and U.S. Pat. No. 6,382,404 to Guldenfels, all of which are assigned to the assignee of the present invention and incorporated herein by reference. A raised rib module is shown in U.S. Pat. No. 5,850,902 to Hicks et al.  
         [0031]    It is intended that the foregoing description be only illustrative of the present invention and that the present invention be only limited by the hereinafter appended claims.