Single color bar code printing on a multi-package

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

0001This invention relates to a package of containers that facilitates proper bar code scanning.

DESCRIPTION OF PRIOR ART

0002Conventional container carriers are often used to unitize a plurality of similarly sized containers, such as cans, bottles, jars and boxes and/or similar containers. Flexible plastic ring carriers are one such conventional container carrier.

0003Such flexible plastic ring carriers for cans and bottles may or may not have labels printed on the carrier. Often it is desirable to add a Universal Product Code (UPC) or "bar code" (the terms "UPC" and "bar code" are used interchangeably herein) to the container to identify individual containers and the carrier to identify the multi-container package, or multi-package. Containers within the multi-package that are individually coded with the bar code enable a bar code scanner or reader (also used interchangeably herein) to read product information, such as price.

0004For simplicity and alignment, it is preferable to print the bar code with a single color, but known carriers lacked sufficient contrast. Conventional carriers require being colored and/or being rendered opaque for bar code printing.

0005Flexible plastic ring carriers may be used to unitize groups of four, six, eight, twelve or other suitable groups of containers into a convenient multi-package. In such cases, it is preferable to block any bar code on the individual container. This will prevent the bar code for individual containers from being read in place of or in addition to the bar code for the multi-pack. When such containers are placed within a multi-package such as a "six pack," difficulties may arise when container bar codes with individual container information are scanned instead of package bar codes with the information relevant to the multi-package or six pack.

0006Traditional multi-packages, such as six-packs, include containers that are positioned in random rotational orientations within the carrier. Each container generally includes an individual bar code which includes information, such as price, regarding the individual container. However, when the bar code for the individual container is scanned as the multi-package price, problems may arise for the vendor. Such problems primarily include a single container price being charged for a multi-container package and the inventory control problems that may result.

0007As such, it is desirable to ensure that the correct bar code is scanned for the correct container and/or multi-package. More specifically, it may be desirable to block the bar codes of individual containers within a multi-package from the scanning process.

SUMMARY OF THE INVENTION

0008The present invention is directed to a package that includes a flexible carrier and a plurality of containers.

0009<patcit id="pcit0001" dnum="US20070295621A"><text>US2007/0295621</text></patcit> discloses a multi-package for carrying an array of containers in a corresponding array of apertures, the multi-package comprising: <ul id="ul0001" list-style="none" compact="compact"><li>a sheet formed of a generally transparent material having a plurality of apertures the sheet containing an absorbing dye within at least a portion of the sheet, the absorbing dye selected to absorb a light from a bar code scanner whereby the sheet appears opaque to the bar code scanner;</li><li>a plurality of containers positioned in respective apertures of the array, and</li><li>a bar code printed with a single color on the portion of the sheet.</li></ul>

0010According to the present invention, such a multi-package is characterised in that the portion of the sheet with the absorbing dye provides bars of the bar code and the single color provides spaces between the bars of the bar code.

0011As a result, a bar code reader is less likely to read the bar code on each container.

0012The carrier of the present invention, although traditionally generally transparent, may additionally include a fluorescing dye. The area of the carrier that includes the dyes preferably extends across an entirety of the carrier however it may alternatively extend through a center of the carrier or across or along any other suitable area of the carrier.

0013Accordingly, the plurality of containers are positioned in the carrier so that each bar code is blocked by either the carrier and/or the containers are oriented in a rotationally inward position toward a center of the package and preferably toward an area of the carrier that includes the absorbing dye and the fluorescing dye. Alternatively, containers may be rotationally oriented in the carrier in any other suitable manner such that a bar code scanner is less likely to read individual bar codes on the respective containers. The area of the carrier that includes the absorbing dye and the fluorescing dye preferably prevents any light from the bar code scanner from contacting and reading the bar codes of the individual containers.

0014According to a preferred embodiment of this invention, a tailored dye and/or pigment package in a homogeneous sheet provides sufficient contrast to print single color bar codes on the transparent sheet. Alternately, the tailored dye and/or pigment package and lane extrusion provides desired printability and/or bar code blocking in a portion of the transparent carrier. According to another embodiment of this invention, opaque colors with lane extrusion provide spot color suitable for single color printing and/or bar code blocking.

0015The absorbing dye may color the sheet cyan. The multi-package may further comprise at least one additional absorbing dye color balancing the sheet. The at least one additional absorbing dye may include a magenta dye and a yellow dye for tri-color balancing. Preferably the tri-color balancing results in a neutral color. The absorbing dyes preferably reduce transmittance by less than about 30 percent.

BRIEF DESCRIPTION OF THE DRAWINGS

0016The above-mentioned and other features and objects of this invention will be better understood from the following detailed description taken in conjunction with the drawings wherein: <ul id="ul0002" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> is a side view of a multi-package of containers assembled in a conventional manner with individual bar codes in random rotational orientations;</li><li><figref idref="f0002">Fig. 2</figref> is a schematic view of a typical bar code reader;</li><li><figref idref="f0003">Fig. 3</figref> is a graph showing absorption curves of various red absorbing dyes and fluorescence frequencies of two UV fluorescing dyes for use with preferred embodiments of this invention;</li><li><figref idref="f0004">Fig. 4</figref> is a top schematic view of a multi-package similar to a package according to one preferred embodiment of this invention;</li><li><figref idref="f0005">Fig. 5</figref> is a side view of a multi-package of containers according to one preferred embodiment of this invention;</li><li><figref idref="f0006">Fig. 6</figref> is a graph showing absorption curves of various absorbing dyes for color balancing according to one preferred embodiment of this invention and;</li><li><figref idref="f0007">Fig. 7</figref> is a top view of multi-package carriers, according to one preferred embodiment of this invention.</li></ul>

DESCRIPTION OF PREFERRED EMBODIMENTS

0017<figref idref="f0001">Fig. 1</figref> shows a multi-package of six containers 60 unitized in a carrier to form a multi-packaging device. As shown, an exterior face of each container 60 includes a machine readable universal product code ("UPC"), referred to herein as bar code 70, printed thereon. Bar code 70 on each individual container 60 permits container 60 to be scanned by a bar code reader or scanner. When bar code 70 on container 60 is scanned by the bar code reader, information, such as the price, about the individual container 60 is retrieved from a computer connected with respect to the bar code reader. According to a preferred embodiment of this invention, the lines on bar code 70 are aligned in a generally horizontal orientation relative to container 60.

0018As shown in <figref idref="f0001">Fig. 1</figref>, a package of individual containers 60 comprises a unitized group of containers 20 sold as a multi-package. The unitized containers 60 are generally randomly oriented so that each container 60 is positioned in a different and/or random rotational orientation within the carrier. The package may have a separate bar code (not shown in <figref idref="f0001">Fig. 1</figref>) which allows information about the package, such as the price of the group of containers 60, to be retrieved when the separate bar code is scanned by the bar code reader. This separate "package" bar code may be printed on the exterior of the package or otherwise affixed to the package by suitable means, such as adhesive.

0019<figref idref="f0002">Fig. 2</figref> shows a schematic of a conventional bar code scanner or reader 100. Bar code reader 100 traditionally uses laser light beams that are scanned across bar code 70 optically. In order to accept the broadest range of configurations, bar code readers 100 have been reported in the literature from wavelengths as low as 630 nm to 940 nm. Many point of sale bar code readers 100 fall in the range of 650 to 670 nm. The configuration of a typical point of sale bar code reader 100 is shown in <figref idref="f0002">Figure 2</figref>. The laser beam is scanned across bar code 70 by moving the disk and/or the mirrors.

0020However, problems and mis-scans may arise if the bar code reader 100 instead scans bar code 70 of the individual containers 60 in lieu of the separate package bar code. Such mis-scans may result in a single container 60 price being charged for a multi-container package.

0021<figref idref="f0004">Fig. 4</figref> shows a top view of a multi-package 10 according to a preferred embodiment of this invention. As shown, multi-package 10 may include a plurality of containers 60, such as cans. Although <figref idref="f0004">Fig. 4</figref> shows one preferred embodiment of this invention wherein each bar code 70 has been oriented into a preferably inward position relative to multi-package 10, an alternative embodiment of this invention includes carrier 15 applied in a suitable position over at least a portion of each respective bar code 70 such that specific orientation is not required. Although cans are shown in <figref idref="f0004">Fig. 4</figref>, bottles or any other commonly unitized container may be used in multi-package 10 according to this invention. Containers 60 are preferably, though not necessarily, like-sized within a single flexible carrier 10.

0022Each carrier 15 preferably includes sheet 20 having a width and length defining therein a plurality of container receiving apertures 25, each for receiving a single container 60. The plurality of container receiving apertures 25 are preferably arranged in longitudinal rows and longitudinal ranks so as to form an array of container receiving apertures 25, such as two rows by three ranks for a six container multi-package, two rows by six ranks for a twelve container multi-package, etc. Container receiving apertures 25 are preferably elongated in a longitudinal direction of carrier 10.

0023Sheet 20 and thus carrier 15 of the present invention are preferably substantially transparent and made of a suitable plastic material, preferably, generally transparent and preferably formed in extruded sheets, such as low to medium density polyethylene. In addition, according to a preferred embodiment of this invention, a light absorbing dye and a fluorescing dye are included in sheet 20, either as an additive during the forming process, such as during extrusion, or post process, such as with inks, tapes or similar post process applications.

0024According to a preferred embodiment of this invention, red dyes are identified and used that absorb the light at about 670 nm. Although traditionally referenced as an infrared absorber, such dyes are in fact visible light in the red region. Although various dyes absorb a significant amount of light in the proper wave band, such dyes do not consistently prevent a read of bar code 70. Additionally, the removal of red light from the generally transparent plastic material resulted in a definite blue cast to resulting carriers 15.

0025According to one embodiment of this invention, the color shift to blue is generally undesirable since bottlers, retailers and consumers generally prefer a neutral colored and/or generally transparent carrier 15. According to one embodiment of this invention, color correction through additional dyes to absorb blue light is generally undesirable as this solution could potentially have resulted in a grey carrier, neutral in color but with an overall attenuation in light transmission. Issues with the color shift, supply of the dyes, and the effectiveness of the UPC blocking effect all contributed to a requirement for an alternative solution, according to one embodiment of this invention.

0026According to a preferred embodiment of this invention, the fluorescing dye comprises specifically a UV fluorescing dye or similar additives that absorb light in the UV region of the spectra and fluoresce in the red visible region of the spectra are desirable for use in connection with sheet 20. Examples of desirable additives include Ranita Ksanta^™ which fluoresces at 600 to 630 nm, and Smartlight® RL 1000 by Ciba Specialty Chemicals which fluoresces at 630 to 640 nm. These materials may yield red hued polyethylene films or sheet 20. <figref idref="f0003">Fig. 3</figref> shows absorption curves for various red absorbing dyes tested, the target range to be blocked and the fluorescence frequencies of two UV fluorescing dyes.

0027By coupling the two dyes, the red absorbing dyes in the range of 660 to 680 nm and the UV fluorescing dyes that translate light in UV wavelengths to the range of 600-640 nm, carrier 15 includes both enhanced blocking effect of the red absorbing dye through added red in the film, and enhanced blocking of color shift from the red absorbing dyes. By compensating for the loss in red by translating UV to the red wavelengths, the "graying" effect of the blue absorbers is minimized in carrier 15 while countering the blue shift by adding red instead of subtracting blue. This combination preferably blocks UPC scans of bar code 70 on individual containers 70 and/or multi-packages 10 while maintaining a neutral color. Additional additives may be included within carrier 15 including a third dye to fine tune a resulting color balance in carrier 15, for instance, to minimize "graying" of carrier 15 and/or enhance translucence of carrier 15.

0028As shown in <figref idref="f0004">Fig. 4</figref>, carrier 15 preferably includes sheet 20 having an absorbing dye and a fluorescing dye, such as a UV fluorescing dye, comprising an entire area 30 of sheet 20. This preferred embodiment of the invention preferably results from the absorbing dye, preferably the red absorbing dye and the fluorescing dye being added during the manufacturing process of sheet 20 and/or carrier 15. Such process preferably includes mixing pelletized plastic with the suitable dye additives before or during the extrusion process, extruding suitable sheet material and then punching such sheet material to form carriers 15. More preferably, the red absorbing dye and the fluorescing dye are mixed with plastic material to form a combined particle that is then suitable for extrusion.

0029As shown in <figref idref="f0005">Fig. 5</figref>, carrier 15 is preferably applied around a sidewall of each respective container 60. As such, preferably directly overlaps with at least one line of each bar code 70 on each container 60, thereby preventing an effective scan by bar code reader 100, even when bar codes 70 are exposed along outer faces of containers 60.

0030Alternatively, such as shown in <figref idref="f0005">Fig. 5</figref>, carrier 15 may include a partial section or area 30 that is treated or otherwise processed to include the absorbing dye and the fluorescing dye. Area 30 preferably comprises a material and/or treatment that results in a portion of sheet 20 that absorbs or reflects light beams emitted from the bar code reader so that the bar code reader cannot read bar codes 70 on containers 60 which are covered or obscured, at least partially, by carrier 15. As used herein, "area" 30 is defined as all or part of carrier 15 including a process, treatment, ingredient, feature and/or quality that does not permit light beams from a bar code reader 100 to pass through carrier 15 and thus scan bar code 70.

0031As described, sheet 20 is formed of a generally transparent material and includes an array of container receiving apertures 25. Area 30 preferably extends through sheet 20 to comprise carrier 15 of the subject invention. As shown in <figref idref="f0005">Fig. 5</figref>, area 30 may extend within sheet 20 through a center of carrier 15, or on top of, underneath or between sheet 20. As such, area 30 may be adhered in sections or strips to sheet 20, such as with an adhesive; area 30 may be applied to sheet 20, such as with a hot stamp, an ink or paint; and/or area 30 may be manufactured into sheet 20, such as in a co-extrusion process.

0032According to one preferred embodiment of this invention wherein the absorbing dye and the fluorescing dye are homogeneously mixed within sheet 20, containers 60 may be placed within carrier 15 without regard to rotational orientation of bar codes 70 relative to multi-package 10.

0033According to another preferred embodiment of this invention, such as shown schematically in <figref idref="f0004">Fig. 4</figref>, the plurality of containers are rotationally oriented in the corresponding array of apertures so that each bar code 70 is positioned so that a bar code reader cannot scan each bar code 70. Although the inclusion of the absorbing dye and the fluorescing dye may alone prevent bar code reader 100 from scanning bar codes 70, such orientation may provide additional security.

0034Such orientation may be more preferable in an embodiment where a single area 30 of sheet 20 that includes the absorbing dye and the fluorescing dye is arranged along a center of carrier 15. As shown in <figref idref="f0005">Fig. 5</figref>, each bar code 70 is rotationally positioned inwardly toward area 30 and a center of a resulting package 10. However, opaque section 30 may be intermittently applied and/or positioned throughout carrier 15 based upon a desired location of bar code 70 on oriented containers 60. In any desirable configuration, each container 60 within carrier 15 may be rotationally oriented within carrier 15 so that bar code 70 is obstructed by an adjacent container 60 and/or by carrier 15.

0035Various desirable methods of orienting individual containers 60 are taught by <patcit id="pcit0002" dnum="US6484478B"><text>Arends et al., U.S. Patent 6,484,478</text></patcit>; <patcit id="pcit0003" dnum="US6688465B"><text>Arends et al., U.S. Patent 6,688,465</text></patcit>; and <patcit id="pcit0004" dnum="US6868652B"><text>Arends et al., U.S. Patent 6,868,652</text></patcit>.

0036According to one preferred embodiment of this invention, a second bar code 80 (or "multi-package code") may be positioned on handle 90, such as shown in <figref idref="f0005">Fig. 5</figref>, or other portion of package 10. The second bar code 80 may include information regarding the multi-package including new pricing and quantity information. Area 30 of sheet 20 thereby provides a dual role of blocking bar codes 70 on individual containers 60 and supporting the second bar code for multi-package labeling.

0037According to a preferred method of the subject invention, carrier 15 having a plurality of container receiving apertures 25 and sheet 20 having an absorbing dye and fluorescing dye area 30 is provided for engagement with a plurality of containers 60. Containers 60 are then positioned within carrier 15 and additionally may be oriented so that bar code 70 of each container 60 is blocked by adjacent containers 60 and/or area 30 of carrier 15. As described in the Arends et al. Patents, each container 60 may be oriented before it is positioned within carrier 15; after container 60 is positioned within carrier 15 or some combination of orienting containers 60 before and after engagement with carrier 15.

0038According to one desired embodiment of this invention, each container 60 is oriented, prior to engagement with carrier 15, so that each bar code 70 faces a corresponding bar code 70 in a transversely adjacent container 60. Carrier 15 is then applied to a desired set of containers 60 resulting in a unitized package 10.

0039According to a preferred embodiment of this invention, a substantially transparent carrier includes a single color bar code printed thereupon. By selecting a narrowly absorbing dye designed to absorb light from bar code lasers, the carrier will appear opaque to the scanner and printing the white spaces of the bar code produces a readable bar code. Desirably, narrowly absorbing dyes include absorbance in the range of between about 650 to about 670 nm, for example.

0040The resulting colorcast of the carrier may be adjusted to a neutral grey color through the use of balancing dyes with only a slight reduction in transmittance. Suitable absorbing dyes may form a light blue or cyan cast to the polymer sheet. Color balancing with narrow absorbing dyes yielding a magenta cast and/or a yellow cast may result in a neutral color. The use of a tri-color approach may provide additional flexibility and/or compensation that a single dye and/or a double dye system. By careful selection of narrowly absorbing dyes a perceived neutral color is achieved, while allowing a substantial portion of the light energy to pass through and maintain transparency, such as, a transmittance reduction of less than about 30 percent and more desirably less than about 20 percent.

0041According to a preferred embodiment of this invention, additives, such as, narrowly absorbing dyes, colored dyes, fillers and/or foaming agents may be used to absorb the light of the scanning laser, to block the light of the laser and/or to scatter the light of the laser, reducing the contrast of the bar code scan below a readable level.

0042According to another embodiment of this invention, the additive or additives used to block the UPC bar codes are confined to a narrow band positioned advantageously to block the reading of the bar code while maintaining clarity of the balance of the carrier, such as, for example, by the use of lane extrusion. Lane extrusion may provide a printable band on the carrier that can be cut out as a printable tab, for example. A printable surface may be combined with bar code blocking functionality. A first lane may be used alone or in conjunction with a second lane to provide a bar code blocking region along either side of the center line of the carrier while maintaining maximum clarity along the outside portion of the carrier so that graphics on the can or bottle may be seen by the consumer.

0043According to a preferred embodiment of this invention, the carrier includes a homogeneous sheet of uniform color and/or co-extrusion of lanes of color in a colorless transparent sheet. Uniform sheet extrusion allows use of a single extruder sheet extrusion line, such as, having a one single screw or one twin-screw extruder with dies and corresponding down stream equipment for producing sheets of uniform thickness.

0044Alternately, the invention includes extruding the color in lanes of an otherwise colorless and transparent sheet. The use of lane extrusion selectively positions the bar code blocking element in an otherwise colorless sheet. The lane element may block the reading of bar codes and/or provide sufficient contrast for single color bar code printing on the carrier. Lane extrusion may provide added printing capability to an otherwise transparent colorless carrier, but may increase capital requirements as the extrusion system may include a second extruder and/or a specialized die.

0045According to a preferred embodiment of this invention, a co-extrusion system of minor components results in lines and/or "lanes" oriented in the machine direction of the extruded sheet, for example. Desirably, lanes are positioned along the mid-line of the carrier and/or in a lane outside the general carrier area, as shown in <figref idref="f0007">Fig. 7</figref>, for example. Lanes may be transparent, colored by a tailored dye package, as discussed above, and/or opaque. Opaque may include extruded standard colors, for example.

0046Although the carriers pictured in <figref idref="f0007">Fig. 7</figref> show a grayed strip along the mid-line, this may not be true in actual practice. The blocking carrier may include any number of materials resulting in any suitable appearance. According to a preferred embodiment, a dye or pigment absorbs the light from the scanning laser without shifting color, such as, a neutral color, but may show an increase in haze when compared to the outer portions of the carrier. A narrowly absorbing dye may leave the central lane with a perceptible colorcast due to the removal of red light, for example. Rebalancing the color by absorption of other visible wavelengths may result in an overall reduction in light transmittance and a "gray" color, as discussed above.

0047According to a preferred embodiment of this invention, the absorbing dyes and/or pigments are used throughout the carrier. Alternately, additives may be excluded from the outside portions of the rings, such as, for the sake of package appearance. Limiting any visual impact to a center lane and preserving the color and clarity of the outer portion of the carrier may be desired by point of sale purchasers, such as, to minimize visual impact. Alternately, other factors, such as, impact on regrind or material costs, may increase desirability of placing the blocker only at critical locations in the carrier.

0048According to another preferred embodiment of this invention, the carrier includes an extruded a strip of opaque color to provide a tab for printing within an otherwise clear and colorless carrier, such as, for spot color. Desirably, proper selection of color and/or loading of color dyes and/or pigments provide single color printing in the spot color area.

0049Alternately, any suitable substance to block the transmittance of light to enhance contrast of the bar code on the carrier may be utilized along the tab line, such as, an opaque pigment like talc and/or titanium dioxide (Ti02) may be extruded into this strip to provide a solid white color, for example. Other suitable pigments are possible to selectively provide a colored lane, such as, carbon black for a black lane.

0050This invention also includes a method of assembling a plurality of containers in a multi-packaging device including: the step of forming a sheet from a plastic material including an absorbing dye, the sheet having a plurality of apertures, the step of engaging the plurality of containers with the plurality of apertures, and the step of printing a bar code with a single color on a portion of the sheet, wherein the single color provides spaces between bars. The method may also include blocking a bar code from a reader. The method may further include the forming lanes within the sheet.

EXAMPLES

0051Selected dyes were compounded into a polyethylene resin. For these examples, separate concentrates were produced for each of the three colors: G2003-06-01 for the cyan dye (0.05% loading), G2003-06-02 for the yellow dye (0.50/0 loading), and G2003-06-03 for the magenta dye (0.5% loading). Absorbance curves for these three concentrates are given in <figref idref="f0006">Figure 6</figref>.

0052After selecting a dye loading to provide a neutral color, the concentrates were blended with polyethylene and extruded into a 14-mil sheet using a 1 inch 24:1 single screw extruder and a inch coat hanger die with a standard casting roll stand. The resulting sheet included a uniform color and 6½ inch width. This dye loading in the sheet blocked the reading of a standard bar code. A BYK Gardiner Haze Gard Plus instrument measured total transmittance, haze and clarity for the sheet. As seen in Table 1 below, the transmittance of light was reduced by about 26% but haze was reduced by 7% and clarity improved by 1%. Text was easily readable through the sheet with graphics and/or colors remaining true. <tables id="tabl0001" num="0001"><table frame="all"><title><b>Table 1. Measures of Sheet Clarity on Laboratory Produced Samples</b></title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="25mm" /><colspec colnum="2" colname="col2" colwidth="17mm" /><colspec colnum="3" colname="col3" colwidth="17mm" /><colspec colnum="4" colname="col4" colwidth="17mm" /><colspec colnum="5" colname="col5" colwidth="18mm" /><colspec colnum="6" colname="col6" colwidth="17mm" /><colspec colnum="7" colname="col7" colwidth="18mm" /><thead><row rowsep="0"><entry morerows="1" rowsep="1" align="center" valign="top">Sample</entry><entry namest="col2" nameend="col3" align="center" valign="top">Transmittance</entry><entry namest="col4" nameend="col5" align="center" valign="top">Haze</entry><entry namest="col6" nameend="col7" align="center" valign="top">Clarity</entry></row><row><entry colsep="0" align="center" valign="top">Average</entry><entry align="center" valign="top">Std. Dev.</entry><entry colsep="0" align="center" valign="top">Average</entry><entry align="center" valign="top">Std. Dev.</entry><entry colsep="0" align="center" valign="top">Average</entry><entry colsep="0" align="center" valign="top">Std. Dev.</entry></row></thead><tbody><row><entry>Control</entry><entry align="char" char=".">89.6</entry><entry align="char" char="." charoff="11">0.44</entry><entry align="char" char=".">12.2</entry><entry align="char" char="." charoff="11">0.83</entry><entry align="char" char=".">87.2</entry><entry align="char" char="." charoff="11">0.37</entry></row><row><entry>Sheet Sample</entry><entry align="char" char=".">66.4</entry><entry align="char" char="." charoff="11">0.22</entry><entry align="char" char=".">11.3</entry><entry align="char" char="." charoff="11">0.93</entry><entry align="char" char=".">88.2</entry><entry align="char" char="." charoff="11">0.42</entry></row></tbody></tgroup></table></tables>

0053The effectiveness of these sheets at blocking bar code scanners was tested using a portable omni-directional scanner produced by Symbol Technologies, a CCD linear hand held scanner, model SC5USB, distributed by IDAutomation, and a Quickcheck^™ PC Verifier produced by Hand Held Products. The Symbol Technologies scanner utilized a 650 nm laser and the other devices utilized 660 nm lasers. Scans were performed using a calibrated conformance standard test card supplied by GS 1.

0054Neither the Symbol Technologies Omni-directional scanner nor the Quickcheck^™ verifier were able to scan the standard bar codes in 25 tries. The CCO scanner would read the bar codes, but the reads were highly irregular with some instances of no reads in 25 attempts and other instances with occasional reads. The hand scanner is much brighter and the scan lines wider, but orientation had to be perfect to read the bar code.

0055A portion of the test sheet was set aside. Bar codes may be printed on certain carriers using a hot stamp method with a single color. Typically, highly colored carriers are used and the print adds the white spaces in the bar code. Single color bar codes do not work with standard transparent carriers because the contrast between the dark and white areas is not sufficient. Typically, a preprinted label may be applied to the conventional transparent the carriers in a separate processing step.

0056The sheet of this example, according to an embodiment of this invention, appears opaque to the bar code scanner. Single color thermal transfer printing for the white spaces of the bar cod was applied to the sheet. The bar code includes a standard pattern, such as, used with highly colored carriers. The bar code readability was tested using each of the three test scanners as described above. The bar code printed on the transparent sheet sample was read 25 of 25 times by both the Symbol Technologies scanner and the IDAutomation scanner. Evaluation of the bar code using the Quickcheck^™ Verifier, showed the bar code to pass ISO standards.

0057A separate experiment tested the effectiveness of lane extrusion to provide targeted bar code printing or selective bar code blocking, as shown above in <figref idref="f0007">Figure 7</figref> and according to a preferred embodiment of this invention. A standard 12-inch coat hanger die was modified by adding a feed port in the lower lip. A 12-inch wide sheet was extruded with a single 0.75 inch colored lane. This sheet was tested for bar code blocking resulting in the lane section matching results of the full sheet as described above. The non-lane areas of the sheet exhibited no blocking effect.

0058While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the scope is defined by the appended claims.