Patent Application
20110138753
This invention is directed to improving performance of a corrugated box or container containing moisture sensitive material such as either ream-wrapped or unwrapped sheets of cut sheet paper which is susceptible to cyclic changes in ambient humidity and temperature. The improvement is achieved with a repulpable water vapor barrier in the inner linerboard.
Corrugated cardboard boxes or containers are commonly used in the storage and shipment of bulk quantities of cut sheet paper commonly used for printing purposes. These bulk boxes or containers are typically designed to hold up to 10,000 sheets, or more, of product, and fifteen or higher of these containers may be stacked on one another. During transportation and storage they may be subjected to rough handling and adverse ambient conditions. For example, during storage they are usually placed in a warehouse, which does not have a controlled atmosphere, whereby the boxes are subjected to cyclic changes in ambient temperature and ambient humidity.
Under conditions of high ambient humidity, and particularly cyclic changes in ambient humidity and temperature, the pulp fibers in the corrugated material experience the effect of hysteresis, whereby the fibers swell and contract as the level of moisture in the air changes. Each cycle weakens bonds between the fibers. As the fiber structure weakens, the side walls of the box bulge outwardly, interfering with storage and handling, and in some cases resulting in failure of the box. In addition to this structural compromise, moisture is increasingly able to penetrate the layers of corrugated into the confinement of the container. This moisture is absorbed by the cut sheets paper within, causing them to wrinkle/warp/deform in such a manner that they will not feed properly into printing equipment. This results in poor print quality and slow production.
A vast majority of moisture resistant containers used to date have commonly been prepared by saturating or coating container blanks with melted wax or with polyethylene after folding and assembly. Such containers can not be effectively recycled and must be generally be disposed of in a landfill. In addition, wax adds a significant weight and cost to the container blank, e.g., the wax can add up to 40% by weight to the container blank.
One aspect of the present invention is directed to provide a container adapted to hold and store moisture sensitive material such as for example, paper or electronic device. The container comprises a top wall, a bottom wall, and a plurality of side walls. Each of the top wall, bottom wall, and a plurality of side walls comprise a corrugated linerboard having an inner surface and an outer surface. At least one of the top wall, bottom wall, and side walls further comprises a coating applied to the linerboard. The coating is positioned at an inner surface of the linerboard to form a coated corrugated linerboard that is a moisture-resistant and resists penetration of water, water vapor or moisture into the container from ambient atmosphere thereby increasing the strength and shelf-life of the container under conditions of cyclic changes in ambient temperature and in ambient humidity. The coating has a coat weight from 1-10 wet #'s total per MSF (thousand square feet). Alternatively, the coating has a coat weight less than 5 wet #'s total per MSF (thousand square feet). The coating is suitable for direct contact with edible material and comprises a single layer in a single pass. The coating is a composition of at least one member selected from the group consisting of a styrene butadiene resin, acrylic polymer, pigment, pulverized mica. Alternatively, the coating is positioned at outer surface of the linerboard.
The container is readily recyclable and repulpable. The top wall, bottom wall, and side walls cooperate with one another to form an interior space that is separated from the ambient atmosphere.
The coated corrugated linerboard has a MVTR of less than 40 grams/m2/24 hours as measured by TAPPI Test Method T-448 om-09 at 72° F., 50% relative humidity. Alternatively, the coated corrugated linerboard has a MVTR of less than 20 grams/m2/24 hours as measured by TAPPI Test Method T-448 om-09 at 72° F., 50% relative humidity. Alternatively, the coated corrugated linerboard has a MVTR of less than 10 grams/m2/24 hours as measured by TAPPI Test Method T-448 om-09 at 72° F., 50% relative humidity.
The coated corrugated linerboard has a MVTR of less than 180 grams/m2/24 hours as measured by TAPPI Test Method T-448 om-89 at 90° F., 90% relative humidity (this test is also known as T 464 om-06). Alternatively, the coated corrugated linerboard has a MVTR of less than 100 grams/m2/24 hours as measured by TAPPI Test Method T-448 om-89 at 90° F., 90% relative humidity. Alternatively, the coated corrugated linerboard has a MVTR of less than 40 grams/m2/24 hours as measured by TAPPI Test Method T-448 om-89 at 90° F., 90% relative humidity.
The coated corrugated linerboard has a Cobb value of less than 40 g/cm2 in 30 minutes as measured by TAPPI Test Method T-441 om-09. Alternatively, the coated corrugated linerboard has a Cobb value of less than 10 g/cm2 in 30 minutes as measured by TAPPI Test Method T-441 om-09.
Another aspect of the present invention is directed to a method of holding, storing, or shipping moisture sensitive material in a moisture-resistant, recyclable, and repulpable container. The method comprising: placing the paper material in an interior space of the container. The container is adapted to hold and store paper material. The container comprises a top wall, a bottom wall, and a plurality of side walls. Each of the top wall, bottom wall, and plurality of side walls comprise a corrugated linerboard having an inner surface and an outer surface. At least one of the top wall, bottom wall, and side walls further comprises a coating applied to the linerboard such that the coating is positioned at an inner surface of the linerboard to form a coated corrugated linerboard that is a moisture-resistant and resists penetration of water, water vapor or moisture into the container from ambient atmosphere thereby increasing the strength and shelf-life of the container under conditions of cyclic changes in ambient temperature and in ambient humidity. The container is readily recyclable and repulpable and the top wall, bottom wall, and side walls cooperate to form an inside space that is separated from the ambient atmosphere.
Alternatively, the present invention is also directed to a container or ream wrap or wrapping sheet having a relatively inexpensive and readily repulpable coating or moisture resistant barrier material incorporated therein to increase resistance of the corrugated material to the effects of ambient humidity, and especially to cyclic changes in ambient moisture and temperature.
While this invention is susceptible of embodiment in many different forms, there is shown in the tables and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
Applicants have discovered a repulpable roll of coated corrugated linerboard material to replace a conventional wax or polyethylene-containing roll wrap. The coated linerboard of the container uses a repulpable and recyclable moisture resistant barrier (i.e., coating barrier).
More specifically, one corrugated die cut container is used according to the present invention. This container is made from a corrugated linerboard which is die cut and scored to fold, forming a bottom and a plurality of sidewalls and a top wall or a lid.
One inner side of at least one wall of the container or one side of the coated linerboard imparts moisture and prevents or substantially reduces the Moisture Vapor Transmission Rate (MVTR) of the coating or coating barrier. The coating does not hinder the application of printable material after the coating and will hot melt with inks and adhesives formulated for this coating. Wide ranges of coat weights such as 1-10 wet #'s total per MSF (thousand square feet) or coat weights 3-8 wet #'s total per MSF (thousand square feet) or coat weights 3-7 wet #'s total per MSF (thousand square feet) can be used in the present invention, including but not limited to coat weights of 4 wet #'s total per MSF (thousand square feet). These coatings and corresponding coated corrugated structures are fully repulpable, recyclable and prevent the container side walls from bulging or curling.
The coating barrier or moisture resistant barrier is applied with any coater including but not limited to a rod coater to one side of the walls of the container or corrugated linerboard. In a preferred construction, the coating barrier is applied to at least one inner side of the walls of the container. Although the coating barrier permits the application of printing or indicia on the inner side of the walls of the container, but the outer side of the walls of the container or the corrugated linerboard is also available for printing and indicia.
The coating or coating barrier or moisture resistant barrier composition may contain at least one of a styrene butadiene resin including but not limited to a modified styrene butadiene resin, acrylic polymer, pigment, pulverized mica, acrylic polymer, pigment, and/or specialty water based additives to enhance the MVTR of the coating barrier specified by customers in the various applications identified. Alternatively, the moisture resistant barrier or the coating barrier can be a composition of polymers and pulverized mica which forms the moisture resistant barrier. Further alternatives for coating barrier composition are: 1) a blend of two modified styrene butadiene resins, an acrylic polymer, and standard water based coating additives to enhance both moisture and grease resistance and 2) a blend of a modified styrene butadiene resin, acrylic polymer, pigment, and premium water based coating additives to enhance the moisture resistance necessary for modified atmosphere conditions. It is possible that other readily repulpable moisture resistant barrier or the coating barrier materials may perform well within the scope of the invention, and should not be limited to the specific coating. It is within the scope of the present invention to use Kraft board as an alternative substrate for coating. A laminated construction of the outer liner may not be required for all applications, and a single ply linerboard coated with the moisture barrier may perform satisfactorily in some applications.
Further alternative coating composition used in the present invention is those that may contain at least resin, cross linker, and anti-foam in any amount. The coating composition may contain from 0 to 99 wt %, preferably from 40 to 90 wt %, more preferably 50 to 80 wt %, and most preferably 60 to 80 wt % resin based on the total weight of the solids in the composition. This range may include 0, 0.25, 0.5, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100 wt % based on the total weight of the solids in the composition, including any and all ranges and subranges contained therein. In a preferred embodiment, the coating composition contains about 71.4 wt % of the resin based on the total weight of the solids in the composition.
The coating composition may contain from 0 to 90 wt %, preferably from 30 to 90 wt %, more preferably 50 to 80 wt %, and most preferably 60 to 80 wt % filler based on the total weight of the solids in the composition. This range may include 0, 0.25, 0.5, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100 wt % based on the total weight of the solids in the composition, including any and all ranges and subranges contained therein. In a preferred embodiment, the coating composition contains about 36.0 wt % of the filler based on the total weight of the solids in the composition.
The coating composition may contain from 0 to 30 wt %, preferably from 5 to 30 wt %, more preferably 10 to 20 wt %, and most preferably 15 to 20 wt % cross linker based on the total weight of the solids in the composition. This range may include 0, 0.25, 0.5, 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 wt % based on the total weight of the solids in the composition, including any and all ranges and subranges contained therein. In a preferred embodiment, the coating composition contains about 2.5 wt % of the filler based on the total weight of the solids in the composition.
The coating composition may contain from 0 to 3 wt %, preferably from 1 to 3 wt %, more preferably 1 to 2 wt %, and most preferably 0.1to 1.0 wt % anti-foam based on the total weight of the solids in the composition. This range may include 0, 0.25, 0.5, 1, 1.5, 1.75, 2, 2.25, 2.5, 3 wt % based on the total weight of the solids in the composition, including any and all ranges and subranges contained therein. In a preferred embodiment, the coating composition contains about 0.1 wt % of the anti-foam based on the total weight of the solids in the composition. The coating is suitable for direct contact with edible material and comprises a single layer in a single pass.
Listed below are the exemplified and nonlimiting functional characteristics of the coated linerboard of the present invention at the above-mentioned coat weights. For example for various coat weights, Cobb test range at a given time as measured by TAPPI Test Method T-441, MVTR test range as measured by TAPPI Test Method T-448 om-89, and Kit (e.g., grease, non-water liquid) level range as measured by TAPPI Test method T-559 cm-02 are as follow:
A) For coat weight of 1 wet #'s total per MSF (thousand square feet): the Cobb value range is 20-40 g/cm2 in 30 minutes, MVTR range is 20-40 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 3-5;
B) For coat weights of 2 wet #'s total per MSF (thousand square feet): the Cobb value range is 15-30 g/cm2 in 30 minutes, MVTR range is 18-38 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 3-5;
C) For coat weights of 3 wet #'s total per MSF (thousand square feet): the Cobb value range is 10-20 g/cm2 in 30 minutes, MVTR range is 10-20 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 5-7;
D) For coat weights of 4 wet #'s total per MSF (thousand square feet): the Cobb value range is 5-10 g/cm2 in 30 minutes, MVTR range is 5-10 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 7-9;
E) For coat weights of 5 wet #'s total per MSF (thousand square feet): the Cobb value range is 4.5-9 g/cm2 in 30 minutes, MVTR range is 4.5-9 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 6-8;
F) For coat weights of 6 wet #'s total per MSF (thousand square feet): the Cobb value range is 4-8 g/cm2 in 30 minutes, MVTR range is 4-8 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 5-7;
G) For coat weights of 7 wet #'s total per MSF (thousand square feet): the Cobb value range is 3.5-7 g/cm2 in 30 minutes, MVTR range is 3.5-7 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 4-6;
H) For coat weights of 8 wet #'s total per MSF (thousand square feet): the Cobb value range is 3-6 g/cm2 in 30 minutes, MVTR range is 3-6 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 3-5;
I) For coat weights of 9 wet #'s total per MSF (thousand square feet): the Cobb value range is 2.5-5 g/cm2 in 30 minutes, MVTR range is 2.5-5 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 2.5-4.5;
J) For coat weights of 10 wet #'s total per MSF (thousand square feet): the Cobb value range is 2-4 g/cm2 in 30 minutes, MVTR range is 2-4 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours), and the Kit level range is 2-3; and
K) Other Alternative functional characteristics of the product at coat weights range of 1-10 wet #'s total per MSF is : the Cobb value range is 2-40 g/cm2 in 30 minutes, MVTR range is 2-40 grams/m2/24 hours (MVTR conditions: 72° F., 50% RH-grams/m2/24 hours) and the Kit level ranges is 1-10.
The Cobb value of the coated linerboard for a given coat weight as measured by TAPPI Test Method T-441 om-09, can be varied widely, but in the preferred embodiment of this invention, the Cobb value of the coated linerboard is less than 40 g/cm2 in 30 minutes, preferably is less than 30 g/cm2 in 30 minutes, more preferably is less than 20 g/cm2 in 30 minutes, and most preferably is less than 10 g/cm2 in 30 minutes. The value may be less than 40, 35, 30, 25, 20, 15, 12, 10, 8, 6, 4, and 2 g/cm2in 30 minutes including any and all ranges and subranges contained therein.
The range of MVTR of the coated linerboard as measured by TAPPI Test Method T-448 om-09 can be varied widely, but in the preferred embodiment of this invention, the MVTR of the coated linerboard is less than 60 gms/m2/day, preferably is less than 40 gms/m2/day, more preferably is less than 20 gms/m2/day, and most preferably is less than about 10 gms/m2/day. The MVTR of the coated linerboard may be less than about 60, 55, 50, 45, 40, 35, 25, 20, 18, 16, 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, and 1 gms/m2/day including any and all ranges and subranges contained therein.
The range of MVTR of the coated linerboard at very hot and humid condition can be varied widely, but in the preferred embodiment of this invention, the MVTR of the coated linerboard as measured by 90° F./90% RH gms/m2*day is less than 200 gms/m2/day, preferably is less than 180 gms/m2/day, more preferably is less than 170 gms/m2/day, and most preferably is less than 50 gms/m2/day. The MVTR of the coated linerboard may be less than about 200, 195, 190, 185, 180, 175, 170, 165, 160, 155, 150, 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 25, 20, 18, 16, 15, 12, 10, 9, 8, 7, 6, 5, 4, 3, 2, and 1 gms/m2/day including any and all ranges and subranges contained therein.
In addition to the above, experiments were conducted to establish differences between the available commercial product (control) and the three container samples 1, 2, and 3 having cut sheet paper contained therein as shown in Table 1. The commercial product (control) and the three container samples 1, 2, and 3 were placed in the atmosphere condition as indicated in the Table 1. The available commercial product is a polyethylene laminate which is neither repulpable nor recyclable. It can be seen that the moisture of the samples 1, 2, 3 and the commercial product were initially measured.
Next, after two weeks, the moisture of the each sample and the commercial product were measured again to determine the change in the moisture content. The MVTR for the samples and the commercial product were measured (1) at 72° F., 50% relative humidity as measured by TAPPI Test Method T-448 om-09 and (2) at 90° F., 90% relative humidity as measured by TAPPI Test Method T-448 om-89. It can be seen from the Table 1 that sample #3 which is a fully repulpable and recyclable embodiment of the present invention shows a remarkable close MVTR value of 2.03 to that of the available commercial product that is not repulpable or recyclable with MVTR of 0.75. Sample #2 was tested such that container was fully open and exposed directly with the ambient humidity to test the effect of a closed vs. an open system on the moisture profile of the coasted linerboard. Sample #1 used alternative coating disclosed in the present invention as described hereinabove.
A study was conducted to determine if the inclusion of 10% by weight of a linerboard coated with the coating composition (a modified styrene butadiene resin, acrylic polymer, pigment, and/or specialty water based additives to enhance the MVTR of the coating barrier) as described hereinabove would significantly affect the slide angle of a fully-processed OCC furnish. According to the American Forest & Paper Association (AF&PA) protocol, an uncoated and a treated sample were pulped, coarse screened, fine screened, and processed in a reverse centrifugal cleaner. Cleaner accepts were tested for slide angle and Scott Bond.
Linerboard samples were received and the uncoated and treated material consisted of clippings, so no cutting was required. The furnish used for the trials is as follows:
For each linerboard type, three pulper batches were required. Each pulper batch was charged with 36 as-is pounds of material.
Pilot pulping was accomplished in a Black Clawson 3-foot laboratory Hydrapulper at 3% consistency, 125 gallons of tap water were placed into the pulper tub, and steam was sparged into the water until a temperature of 140° F. was reached. Alkali was added to adjust the water pH to a value of 8.5. The appropriate amount of waxed and/or unwaxed linerboard was added into the pulper tub. The pulper lid was closed, and the pulper motor was energized for 15 minutes.
Prior to pulping, sufficient water was placed into Tank #2 to dilute three pulper batches to a consistency of 1%. This water was mixed with steam to a temperature of 163° F. The pH of the water was then adjusted with acid to a value of 8.5.
Prior to processing, all equipment to be used was flushed with water at 163° F. to prevent shock-cooling of the wax-containing streams.
Coarse screening was done in a Gauld Periflow pressure screen, Model 140, with basket perforation diameter of 0.063-inch. Accept rate from the screen was metered and set at 90 gpm, while reject rate was metered and set at 10 gpm. At steady state, a sample of the rejects was taken. Fine screening was done in an Ahlstrom M-200 Centrisorter, equipped with a 0.010-inch slotted basket. Accept rate was metered and set at 90 gpm, while the reject rate was metered and set at 10 gpm. At steady state, a sample of the rejects was taken.
Centrifugal cleaning was accomplished in a Beloit Uniflow reverse cleaner. The fine screen accepts were fed at a pressure of 25 psig, and the accept pressure was controlled at 10 psig. Approximate flow rates under these conditions are 60 gpm feed and 8 gpm reject. At steady state, a sample of the rejects was taken.
The cleaner accepts were processed immediately, to minimize cooling. Standard handsheets (1.2 grams OD fiber) were made, recirculating the sheet mould white water each time. The first seven handsheets were discarded. The seventh and subsequent handsheets were used for testing. The handsheets were pressed in standard two-stage fashion prior to drying to 7.5% moisture content (approximate) on a speed-dryer maintained at 250° F. All handsheets were conditioned at standard humidity and temperature for at least 12 hours prior to testing.
Five pairs of conditioned handsheets were tested for slide angle per TAPPI Test Method T 815 om-07 (felt-to-felt side). Slide angle was measured with Vinings Industries Executive IV tester. This unit used a hydraulic piston to raise the testing platform at a smooth and uniform rate. Prior to testing, the unit was calibrated to a rise rate of 1.5 degrees per second. Calibration was checked periodically throughout the testing procedure. Testing was performed in the conditioning room. Since the samples to be tested were handsheets rather than linerboard, it was necessary to modify the sample weight so that it would hold the sheets together but not penetrate them. This task was accomplished by gluing a piece of sandpaper to the smooth side of the weight; this sandpapered side was placed against the top sheet. Two tests were done on each pair of handsheets. Handsheets were placed felt side to felt side. After the first test, the bottom sheet was rotated clockwise 90 degrees, while the top sheet was rotated counterclockwise by 90 degrees. The second test was then performed.
Scott Bond testing was performed, according to TAPPI Test Method T 569 om-09.
For the uncoated (control) trial, all pulp streams looked normal and comparable to other uncoated trials done previously.
After the first pulper batch was completed for the treated material trial, it was noticed that a few large unpulped pieces were still in the slurry. Closer inspection of one of the pieces showed that it was poorly-wetted. There were also a large number of white flecks of material in slurry. It was decided to increase the pulping time by 5 minutes to improve fiberization. When this increase was applied to the next pulper batch, no large pieces were detected.
White flecks were noted in the coarse screen rejects, but it did not appear that they had been selectively removed. However, a larger amount was noted in the fine screen rejects, indicating some sort of barrier separation. Still, a good number of flecks made it to the cleaners. Almost none of the flecks were removed by the cleaners, so they ended up in the cleaner accepts.
Final handsheets from both trials looked similar, except for the presence of a large amount of with flecks in handsheets from the treated trial.
Table 2 contains slide angle test and statistical data.
Table 3 contains data from Scott Bond tester.
Table 4 contains data from Slide Angle Testing.
All the three tables are attached herein in Appendix I.
Based on strength and slide angle, the coated linerboard of the present invention passed the AF&PA protocol for defining repulpability and recyclability. No wax-based treatment evaluated previously has produced such a small slide angle decrease.
For reference only, the following testing methods below are generally known in the related art and were used to analyze, evaluate and support the present invention as described hereinabove:
TAPPI Test Method T 448 om-09—Provides for the gravimetric determination of the moisture vapor transmission rate (MVTR) of sheet materials at a 72° F., 50% RH environment on one side with desiccant on the other side. The MVTR is a means for measuring the ability of a material to protect contents that are enclosed within the material from undesirable changes due to the transmission of water vapor to or from the surrounding environment.
TAPPI Test Method T 464 om-06—Similar to the T-448 method, this method is a gravimetric determination of the MVTR of sheet material a coated material at elevated temperature and humidity, specifically at a 90° F., 90% RH environment.
TAPPI Test Method T 441 om-09—A test method for determining the quantity of water absorbed by a test sample in direct contact with the water for a specified time under standard conditions. Water absorption is a factor of various characteristics of paper or linerboard such as sizing, porosity or coatings, etc.
TAPPI Test Method T-815—This method determines the coefficient of static friction of most packaging materials by measuring the angle at which one test material surface begins to slide against another inclined surface as the incline is increased at a constant and prescribed rate.
TAPPI Test Method T 569 om-09—Scott Bond test is used to determine the Z-directional strength of a sheet type specimen to evaluate the potential for structural failures or delamination within the interior of the sheet.
TAPPI Test Method T 559 cm-02—The Kit Test is a procedure for testing the degree of repellency and/or the antiwicking characteristics of paperboard treated with fluorochemical sizing agents which can impart hydrophobic characteristics to paper through the reduction in the surface energy of the sheet by a surface treatment of the fibers.
TAPPI Test Method T 402 sp-08—This test method identifies the practice for paper and paper based sample conditioning and determines the appropriate atmospheric environments for testing.
The above referenced test methods were utilized to prepare the sample and conduct the testing which has been reported in this document. TAPPI test methods refer to methods developed by the Technical Association of Pulp and Paper Industries. These are the primary testing methods used within the Test Lab and reflect the standard within the paper industry. The ASTM test method, American Society for Test Materials, is another world recognized technical association which develops testing methods for all industries.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
This application claims priority to U.S. provisional patent application Ser. No. 61/285,599, filed on 12 Dec. 2009, to U.S. provisional patent application Ser. No. 61/297,574, filed on 22 Jan. 2010, all of which are hereby incorporated hereinto by reference as if fully restated herein.
| Number | Date | Country | |
|---|---|---|---|
| 61285599 | Dec 2009 | US | |
| 61297574 | Jan 2010 | US |
