Abstract:
The present invention is directed to a storage system including a biodegradable plastic material that can be used in applications where biodegradability and biocompatibility are among primary desirable features, while having qualities which are desired for the various uses of the storage system. The present invention includes process to make the storage system and for transporting article wherein they can be stored at their destination.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to PCT Application No. PCT/US2010/020740 filed on Jan. 12, 2010, which claims priority to U.S. Provisional Application No. 61/143,941 filed on Jan. 12, 2009, the complete disclosures of which, in their entireties, are herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to an ecologically friendly biodegradable storage system which can be used for storing and transporting a variety of articles. 
     BACKGROUND OF THE INVENTION 
     Containers and bags used for storing and transporting articles have established a place in daily life. These containers and bags can be used for a child&#39;s lunch or for various medical equipment and medical specimens having specific requirements. 
     It is recognized in the industry that plastic films used in the manufacture of these bags and containers are superior in transparency and heat seal-ability as required in general packaging applications. Transparency is normally indicated in terms of light beam transmittance, the higher the transmittance, the better the transparency. Films with a high level of transparency are preferred as packaging material because the contents are visible from the outside. 
     Commonly, conventional plastic products, particularly packaging materials and “bags” are discarded soon after use resulting in disposal problems, which are numerous and must be recognized as an issue for an ecologically conscious society. Most particularly, general packaging plastics, polyethylene, polypropylene, polyethylene terephthalate (PET), etc. can be cited as problematic. These materials are high in calorific value produced during burning, which may result in incineration problems. In addition, polyvinyl chloride is resistant to burning based on its self-extinguishing property. Therefore, plastic products and materials are buried as method of disposal. Due to their chemical and biological stability, they decompose very slowly. Thus, it would be an ecologic benefit to produce plastic films used to make common bags and containers low in calorie, decompose in the soil, and are safe. 
     There have been many attempts to make degradable articles, however, because of costs, the difficulty in processing, and end-use properties, there has been little commercial success. Many compositions that have excellent degradability have only limited process-ability. Conversely, compositions which are processed easily have reduced degradability. 
     This invention is directed to a storage system which includes unique plastic materials that can be used in applications where biodegradability and biocompatibility are among primary desirable features of such applications, while having qualities which are desired for the various uses of the storage system. Further, their products must be a commercially viable method based on cost and is ecologically friendly. 
     BRIEF SUMMARY OF THE INVENTION 
     In a first embodiment, the invention is directed to an ecologically friendly storage system including a biodegradable plastic bag material, wherein the biodegradable plastic material consists essentially of a low density polyethylene, a biodegradable plastic additive; and a polymer softening additive. The storage system includes at least one individual storage compartment made of the biodegradable plastic bag material, having an exterior and interior side, wherein at least one sealable device is attached to a first side and a second side of the interior side. 
     In another embodiment, the invention is directed to a process for an ecologically friendly storage system including the steps of (a) placing low-density polyethylene polymer pellets into a clean tumbling mixer; (b) adding the appropriate amount of polymer softening additive and a biodegradable plastic additive in to the mixer; (c) mixing the polymer and additives in the tumbling mixer for at least half an hour; (d) moving the polymer from the mixer to a hopper of an extrusion machine; (e) pushing a resultant biodegradable plastic material of (a) through (d) through the injection head of the extruder while the mixed polymer is melted inside the injection head; (f) pushing the biodegradable plastic material through a circular die, forming a thin tube; (g) flattening the tube passing it through converging slats and rollers to form at least one individual storage compartment; (h) slitting the flattened tube on one or both sides to form the opening of the bag; and (i) running the flattened tube through a side sealing machine to seal the sides and separate to form individual bags. 
     In yet another embodiment, the invention is directed to an ecologically friendly storage system including a degradable plastic material having at least one of (i.) a low density polyethylene, (ii.) a biodegradable plastic additive; or (iii.) a polymer softening additive. Further, the system has at least one individual storage compartment including the degradable plastic material having an exterior and interior side, wherein at least one sealable device is attached to a first side and a second side of the interior side. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial side view of a first embodiment of a storage system of the present invention, illustrating the attachment to a second system; 
         FIG. 1A  is an exploded side view of a first embodiment of a storage system of the present invention, illustrating the sealable device; 
         FIG. 2  is a side view of an alternate design of the first embodiment of a storage system according to the present invention illustrating the attachment to a second system; 
         FIG. 3  is a plan view of an alternate design of the first embodiment of a storage system illustrating a second individual storage compartment divided by a sealable device; 
         FIG. 4  is a plan view of another alternate design of the first embodiment of a storage system illustrating a second individual storage compartment separated by a partition; 
         FIG. 4A  is a plan view of an alternate configuration of the storage system of  FIG. 4 , illustrating the system intact; 
         FIG. 4B  is a plan view of the alternate configuration of the storage system of  FIG. 4A , illustrating the system detached; 
         FIG. 5  is a plan view of another embodiment of the storage system of the present invention; and 
         FIG. 5A  is a top view of the embodiment of the storage system in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The terminology includes the words specifically mentioned, derivatives thereof and words of similar import. The embodiments discussed herein are not intended to be exhaustive or to limit the invention to the precise form disclosed. These embodiments are chosen and described to best explain the principle of the invention and its application and practical use and to enable others skilled in the art to best utilize the invention. 
     In a first embodiment, the invention is directed to an ecologically friendly storage system including a biodegradable plastic bag material, wherein the biodegradable plastic material consists essentially of a low density polyethylene, a biodegradable plastic additive; and a polymer softening additive. Referring to  FIGS. 1 and 1A , the storage system  10  includes at least one individual storage compartment  12  made of the biodegradable plastic bag material, having an exterior  14  and interior side  16 , wherein at least one sealable device  18  is attached to a first side  16 A and a second side  16 B of the interior side  16 . In addition, the storage system  10  includes at least one attachment means  20  attached to a first exterior side  14 A of the individual storage compartment  12 . As illustrated in  FIG. 1 , an attachment means most commonly extends from the first exterior side  14 A and a second exterior side  14 B. 
     In the first embodiment of the storage system, the low density polyethylene is about 93.1 to about 94.9 percent by weight of the biodegradable plastic material, the biodegradable plastic additive is about 0.5 to about 1.9 percent by weight of the biodegradable plastic material, and the polymer softener additive is about 4.1 to about 5.9 percent by weight of the biodegradable plastic material. Further, this formulation produces a biodegradable plastic which degrades at least 99 percent in 5 years in an aerobic or anaerobic environment when the biodegradable plastic material has a thickness of about 0.04 mm to about 0.06 mm. 
     It will be appreciated by those of skill in the art that modifications of the components will result in modifications to characteristics of the properties of the material. Thus, the present formulation is unique to capture the desire characteristics in addition to the biodegradable properties for its intended use. Further, as can appreciated by those of skill in the art, the formulation of the biodegradable plastic material must appreciate the horizontal stress, e.g. stress made by the seal  18  and attachment  20  devices simultaneously with the vertical weight of any contents of the storage compartments  12 ,  12 X. 
     In the first embodiment, the storage system  10  includes an attachment means  20  incorporating a plurality of extending interlocking projections  22 . The plurality of interlocking projections  22  are most preferably arrow-like projections, wherein the arrow-head is sized to allow perpendicular/horizontal movement of the individual storage compartment  12  in the “interlocked” position attached to another storage system  10 X. Based on the design of the system  10  multiple attachments are possible to a plurality of systems  10 X, thus it is appreciated that multiple systems can exist extending horizontally from the sealable device  18 . 
     In a first embodiment, the sealable device  18  is comprised of a male section  24  having a plurality of extending projections  26 A,  26 B extending from a base  28  attached to the first interior side  16 A of the individual storage compartment  12 , wherein at least one the of the extending projections  26 A is longer than the other extending projections  26 B. A female section  30  extending from a base  32  attached to the second interior side  16 B of the individual storage compartment  12  has a plurality of accepting cuffs  34 , wherein the accepting cuffs  34  are positioned to receive the other extending projections  26 B and secure the at least one the of the extending projections longer than the other extending projections  26 A against an exterior portion  34 A of adjacent accepting cuffs. The female section  30  of the sealable device  18  define apertures  36  aligned substantially central to each accepting cuff  34 . This is specifically designed to allow attachment and release by the female section  30  without excess stress on the biodegradable material, thereby, avoiding “tearing” which would render the “bag” useless. It should be noted that the use of the “aperture design” coincides with formulation which produces a material having the characteristics of (horizontal) designed stress, texture and clarity as discussed herein. 
     Referring to  FIG. 2 , a variation of the sealable device  118  is illustrated wherein the projections  126  are of equivalent size and each is secured within an accepting cuff  134  aligned to receive the projections  126 . 
     Referring to  FIG. 3 , in another variation of the first embodiment, the storage system  10  comprises a second compartment  12 X having a sealable device  18 X on a first end  38 X, wherein the at least one individual storage compartment  12  and the second compartment  12 X are continuous but divided by the second sealable device  18 X. The second sealable device  18 X allows access from the individual storage compartment  12  in the disengaged position or can act as a “seal” in the engaged configuration. One of skill in the art would appreciate that additional individual compartments  12 X can be added, thereby expanding the system  10  in the vertical direction based on the location of the sealable device  18 X. 
     Referring to  FIG. 4 , in yet another variation of the first embodiment, the second sealable device  18 X is positioned on a second end  40 X of the second storage compartment  12 X, wherein the first  12  and second  12 X storage compartments are separated by a partition  42 . Thus communication is prohibited of the first  12  and second  12 X compartments. Thus, there can be no mixing of the content of the individual storage compartment  12  and the second storage compartment  12 X. 
     Referring to  FIGS. 4A and 4B , other variations of this embodiment are illustrated wherein the partition  42  is perforated and detachable and positioned askew to a median position between the sealable devices  18 ,  18 X. 
     It should be appreciated the use of multiple compartments (extending vertical to the sealing device) and additional systems (extending horizontal to the sealing device) allows the reduction of materials, thus resulting in reduced costs to the consumer and reduced ecological stress based on degradation requirements. Further, the invention reduces waste by reducing the consumption at the end use level by having multiple versatility which allows usability for separation and storing multiple items in 1 transporting system. 
     In another embodiment, the invention is directed to a process to produce a storage system including the steps of (a) placing low-density polyethylene polymer pellets into a clean tumbling mixer; (b) adding the appropriate amount of polymer softening additive and a biodegradable plastic additive in to the mixer; (c) mixing the polymer and additives in the tumbling mixer for at least half an hour; (d) moving the polymer from the mixer to a hopper of an extrusion machine; (e) pushing a resultant biodegradable plastic material of (a) through (d) through the injection head of the extruder while the mixed polymer is melted inside the injection head; (f) pushing the biodegradable plastic material through a circular die, forming a thin tube; (g) flattening the tube passing it through converging slats and rollers to form at least one individual storage compartment; (h) slitting the flattened tube on one or both sides to form the opening of the bag; and (i) running the flattened tube through a side sealing machine to seal the sides and separate to form individual bags. 
     Additionally, the process could include expanding the size of the tube by introducing air prior to (g). Though it is appreciated that no contaminants should exist, any contaminants which exist should be removed, most preferably after step (e). 
     In this embodiment, the low density polyethylene is about 90 to about 99 percent by weight of the biodegradable plastic material, the biodegradable plastic additive is about 0.2 to about 5 percent by weight of the biodegradable plastic material and the polymer softener additive is about 0.8 to about 10 percent by weight of the biodegradable plastic material. The plastic biodegradable biodegrades at least 99 percent in 5 years in anaerobic or aerobic environment and has a thickness of about 0.04 mm to about 0.10 mm. 
     Most particularly, the low density polyethylene is 94.0 percent by weight of the biodegradable plastic material, the biodegradable plastic additive is 1.0 percent by weight of the biodegradable plastic material and the polymer softener is 5.0 percent by weight of the biodegradable plastic material. This most particular designation of components results in a biodegradable plastic material that has a luminous transmittance of about 90.4 percent. 
     Similar to the previous embodiment and illustrated in  FIGS. 1 and 1A , the process of this embodiment forms a storage system (not shown), wherein at least one individual storage compartment comprising the biodegradable plastic bag material has an exterior and interior side, wherein at least one sealable device is attached to a first side and a second side of the interior side and at least one attachment means is attached to a first exterior side of the individual storage compartment. 
     One of skill in the art would appreciate the sealable device and the attachment means can be formed during the extrusion process or can be attached later, in the appropriate location of the individual storage compartment. Specifically, there are 3 different processes of adding the sealable device and the attachment means to the system; 1) they are formed separately, and later laminated on to the system by heat, 2) they are a part of the direct extrusion, e.g. they are formed with the biodegradable plastic material formed in the same circular die that forms the system or “a bag”, and 3) they are formed in a secondary stage of the extrusion and formed by a separate die, wherein formation of the sealable device and the attachment means is substantially at the same time of the extrusion of the biodegradable plastic material. This process requires a separate hopper to hold the material of the sealable device and the attachment means and a separate injection gun to inject the material into the necessary die. This method is used when different colors are desired for the sealable device and/or attachment means and the biodegradable plastic material. 
     By the process of this embodiment, a storage system is produced (not shown) wherein at least one individual storage compartment, made of the biodegradable plastic material has an exterior and interior side, wherein at least one sealable device is attached to a first side and a second side of the interior side. Similar to the previous embodiments and illustrated in  FIGS. 1 and 1A , the at least one attachment means is attached to a first exterior side of the individual storage compartment, wherein the attachment means includes a plurality of extending interlocking projections. The sealable device includes a male section having a plurality of extending projections extending from a base attached to the first interior side of the individual storage compartment, wherein at least one the of the extending projections is longer than the other extending projections. A female section extending from a base attached to the second interior side of the individual storage compartment has a plurality of accepting cuffs, wherein the accepting cuffs are positioned to receive the other extending projections and secure the at least one the of the extending projections longer than the other extending projections against an exterior portion of adjacent accepting cuffs. 
     One skilled in the art would appreciate a second storage device could be attached via the attachment device; and the storage system is transported with the attached first and second storage devices as a single unit. In the storage system of this embodiment, the plastic material will not contaminate any article contained therein and will allow a first and second storage system to be stored at the same temperatures or the first and second storage systems can be stored at different temperatures. Further, it is recognized that the first and second storage systems biodegrade in an aerobic or anaerobic environment at the same rate of time. 
     Referring to  FIGS. 5 and 5A , in yet another embodiment, the invention is directed to an ecologically friendly storage system  210  including a degradable plastic material having at least one of (i.) a low density polyethylene, (ii.) a biodegradable plastic additive; or (iii.) a polymer softening additive. Further, the system  210  has at least one individual storage  212  compartment including the degradable plastic material having an exterior  214  and interior side  216 , wherein at least one sealable device  218  is attached to a first side  216 A and a second side  216 B of the interior side  216 . The storage system  210  may include a second compartment  240 X, wherein the at least one individual storage compartment  212  and the second compartment  240 X are separated by a partition  242  positioned substantially perpendicular to the at least one sealable device  218 . The partition  242  may be a varied distance from the sealable device  218  and either centered in regard to the sealable device  218  or askew. The partition  242  may allow communication between the at least one storage compartment  212  and the second compartment  240 X will operate independently of the sealable device  218 . One skilled in the art would recognize that the sealable device  218  in this embodiment could be modified to be two separated (identical or non-identical) sealing devices (not shown) allowing the complete separation of the partitioned sections  212  and  240 X, as illustrated in the present embodiment, thus forming two separate bags (not shown). 
     EXAMPLE 1 
     In a first example of the biodegradable plastic material, the low density polymer is low density polyethylene (LDPE) and is 94.0 percent of the biodegradable plastic material, the polymer softening material is ethylene vinyl acetate (EVA) and is 5.0 percent by weight of the biodegradable plastic material, and the biodegradable additive is ECM Masterbatch pellets produced by ECM Biofims Inc. of Plainsville, Ohio (USA), and is 1.0 percent by weight of the biodegradable plastic material. The biodegradable plastic material of this Example 1, is produced by the method as described herein. The biodegradable plastic material of Example 1 has the following characteristics defined in Table 1. 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 No. 
                 Test item 
                 Test method 
                 Test condition 
                 Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 Tensile 
                 American Society 
                 Width: 
                 machine 
                 25.3  
               
               
                   
                 strength 
                 for Testing and 
                 25 millimeters 
                 direction 
                 MegaPascal  
               
               
                   
                   
                 Materials (“ASTM”) 
                 (“mm”) 
                 (“MD”) 
                 “MPa” 
               
               
                   
                   
                 D882-02 
                 Test speed: 
                 cross direction 
                 10.5 MPa 
               
               
                   
                   
                   
                 50 mm/minutes 
                 (“CD”) 
                   
               
               
                   
                   
                   
                 (“min”) 
                   
                   
               
               
                   
                   
                   
                 Grip separation: 
                   
                   
               
               
                   
                   
                   
                 50 mm 
                   
                   
               
               
                 2 
                 Tear strength 
                 ASTM D1004-07 
                 Thickness: 
                 MD 
                 4.8 Newton 
               
               
                   
                   
                   
                 0.048 mm 
                   
                 (“N”) 
               
               
                   
                   
                   
                   
                 CD 
                 3.3 N 
               
             
          
           
               
                 3 
                 Total luminous 
                 ASTM D1003-07ε1 
                 Thickness: 
                 90.4% 
               
             
          
           
               
                   
                 transmittance 
                 method A 
                 0.048 mm 
                   
                   
               
               
                   
               
             
          
         
       
     
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.