Die-cut patterns for blister package
10450126 ยท 2019-10-22
Assignee
Inventors
- Jacob D. Branyon (Hartsville, SC, US)
- Donald McArthur (Oswego, NY, US)
- Benjamin Davis (West Chester, OH, US)
Cpc classification
B65D75/327
PERFORMING OPERATIONS; TRANSPORTING
B65D83/0445
PERFORMING OPERATIONS; TRANSPORTING
B65B61/025
PERFORMING OPERATIONS; TRANSPORTING
B65B9/045
PERFORMING OPERATIONS; TRANSPORTING
International classification
B65D83/04
PERFORMING OPERATIONS; TRANSPORTING
B65B9/04
PERFORMING OPERATIONS; TRANSPORTING
B65B61/02
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A blister package is formed for retaining individual products. The package includes a receptacle substrate having a sealing flange and at least one receiving cell formed to retain product therein. A polymer top layer covers the cell and a portion thereof is sealed to the sealing flange. A score pattern is formed in at least one surface of the top layer and overlapping the cell. The score pattern is defined by a first plurality of score lines formed in a repeating pattern and a second plurality of score lines formed in a repeating pattern. The first and second plurality of rows overlap one another to define a plurality of intersections, with the overall score line pattern having a total linear length of the score lines per cell of at least 5 inches and a total number of score line intersections per cell of at least 10.
Claims
1. A blister package for retaining individual products, the package comprising: a receptacle substrate, the receptacle substrate having a sealing flange and at least one receiving cell formed to retain product therein, the sealing flange surrounding the at least one receiving cell, and a cell area surrounded by and defined inwardly of the sealing flange, and a top layer covering the cell area of the at least one receiving cell and a portion thereof overlapping and sealed to the sealing flange, the top layer consisting essentially of a polymer material, and a score pattern formed in at least one surface of the top layer and overlapping the cell area of the at least one receiving cell, the score pattern formed for promoting propagation of a tear in the top layer upon application of a transverse push force of the product within the at least one receiving cell against the portion of the top layer overlapping the cell area of the at least one receiving cell, the score pattern defined by a first plurality of rows of score lines formed in a repeating pattern, the pattern of the first plurality of score lines including a series of elongated line segments each extending substantially continuously across the top layer overlapping the cell area of the at least one receiving cell and extending substantially continuously between spaced positions on the sealing flange that surrounds the cell area, and a second plurality of rows of spaced score lines formed in a repeating pattern across the top layer overlapping the cell area of the at least one receiving cell, the first and second plurality of rows overlapping one another to define a plurality of score intersections, and the score pattern having a total linear scored length of score lines per cell of at least 5 inches, and the total number of score intersections created by the score lines within the top layer covering the at least one receiving cell is at least 10.
2. A blister package as in claim 1, wherein the portion of the top layer covering the cell area of the at least one receiving cell is less than 0.5 square inches.
3. A blister package as in claim 1, wherein the second plurality of score lines includes a repeating pattern of circles.
4. A blister package as in claim 3, wherein the circles vary in diameter within the pattern.
5. A blister package as in claim 1, wherein the first plurality of score lines includes a repeating pattern of angled straight lines.
6. A blister package as in claim 1, wherein the first plurality of score lines includes a repeating pattern of crossed straight lines.
7. A blister package as in claim 3, wherein the repeating pattern of circles includes a plurality of concentric circles.
8. A blister package as in claim 1, wherein one of the plurality of score lines includes a repeating pattern of angled straight lines.
9. A blister package as in claim 1, wherein the first plurality of score lines includes a repeating pattern of chevrons.
10. A blister package as in claim 9, wherein the second plurality of score lines includes a pattern of chevrons positioned in an opposing direction from the first plurality.
11. A blister package as in claim 1, wherein the second plurality of score lines includes a repeating pattern of zig-zag lines.
12. A blister package as in claim 1, wherein the second plurality of score lines includes a repeating pattern of curved lines formed in multiple rows across the at least one receiving cell.
13. A blister package as in claim 1, wherein one of the pluralities of score lines includes a repeating pattern of parallel straight lines formed parallel to the machine direction during the formation of the top layer.
14. A blister package as in claim 1 wherein the top layer comprises a laminate composed of multiple layers of polymer material.
15. A blister package as in claim 1 wherein the top layer further comprises a seal coating, and wherein the top layer is heat sealed to the sealing flange of the receptacle substrate, the seal coating facilitating heat sealing of the top layer to the sealing flange.
16. A blister package for retaining individual products, the package comprising: a receptacle substrate, the receptacle substrate having at least one receiving cell formed to retain product therein and a sealing flange surrounding the at least one receiving cell, and a polymer top layer covering the at least one receiving cell and a portion thereof overlapping and sealed to the sealing flange, and a score pattern formed in at least one surface of the top layer and overlapping the at least one receiving cell, the score pattern formed for promoting propagation of a tear in the top layer upon application of a transverse push force of the product within the at least one receiving cell against the portion of the top layer overlapping the at least one receiving cell, the score pattern defined by a first plurality of score lines formed in a repeating pattern, the pattern of the first plurality of score lines including lines extending substantially continuously across the portion of the top layer overlapping the at least one receiving cell, from between at least two opposing, spaced positions adjacent the sealing flange, and a second plurality of score lines formed in an repeating pattern across the portion of the top layer overlapping the at least one receiving cell, the first and second pluralities of score lines overlapping one another to define a plurality of score intersections within the portion of the top layer overlapping the at least one receiving cell, wherein each of the score lines in the first plurality create within the continuous portion of the lines a plurality of score intersections with the score lines within the second plurality, wherein the score pattern comprises a total number of score intersections of at least 10, the score pattern comprises a total linear scored length of score lines overlapping the at least one cell of at least 5 inches, and the portion of the top layer inwardly of the sealing flange and overlapping the at least one receiving cell having an area of less than 0.5 square inches.
17. A blister package as in claim 16 wherein the score pattern comprises a total number of score intersections of at least 12.
18. A blister package as in claim 16 wherein the score pattern comprises a total linear length over the at least one receiving cell of at least 6 inches.
19. A blister package for retaining individual products, the package comprising: a receptacle substrate, the receptacle substrate having a sealing flange and a plurality of receiving cells, each receiving cell formed to retain product therein, and a portion of the sealing flange surrounding each receiving cell, and a polymer top layer covering the receptacle substrate, overlapping each receiving cell and a portion thereof sealed to the sealing flange for enclosing each receiving cell, and a score pattern formed in at least one surface of the top layer and overlapping each of the plurality of receiving cells, the score pattern formed for promoting propagation of a tear in the top layer upon application of a transverse push force of the product within a receiving cell against the portion of the top layer overlapping the receiving cell, the score pattern defined by a first plurality of elongated score lines formed in a repeating pattern, the pattern of the first plurality of score lines including multiple lines extending substantially continuously across a portion of the top layer overlapping each of the receiving cells and each of the multiple lines extending continuously between two opposing, spaced positions adjacent the sealing flange surrounding each of the receiving cells, and a second plurality of elongated score lines formed in an offset repeating pattern across the portion of the top layer overlapping each of the receiving cells, the first and second pluralities of score lines defining an overall scoring length and overlapping one another to define a plurality of score intersections for each receiving cell, wherein the score pattern comprises a total number of score intersections of at least 10 positioned over each receiving cell, and wherein the ratio of linear score line length to the area of the portion of the top layer overlapping each receiving cell is in excess of 10.6.
20. A blister package as in claim 19 wherein the score pattern comprises a total linear length per cell of at least 5 inches.
21. A blister package as in claim 19 wherein the ratio of linear score line length to the area of the top layer overlapping each receiving cell is in excess of 12.8.
22. A blister package as in claim 19 wherein the area of the top layer overlapping each of the receiving cells is less than 0.5 square inches.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) For the purpose of illustrating the invention, there is shown in the drawings a number of forms which are presently preferred; it being understood that the invention is not limited to the precise arrangements and instrumentalities shown.
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DETAILED DESCRIPTION
(8) Referring now to the drawings, where like numerals identify like elements, there is shown in
(9) In
(10) The score pattern 22 in
(11) In
(12) As shown, the relatively outer part 34 of the top layer 14 is the structural portion of the layer and is formed of a polymer material. The second or inner part 36 of the top layer 14 forms the sealing surface for attachment of the top layer 14 to the sealing flange 18. Preferably, a seal coating 36 is applied to the inside surface of the outer part 34. The seal coating 36 is provided to facilitate heat sealing of the top layer 14 to the flange 18. Alternatively, the inner part 36 of the top layer may be a separate polymer layer and may be formed as part of a laminate structure, with the inner part being compatible with the material of the sealing flange. A laminate structure may also be provided as the structural part of the top layer and a separate heat seal coating may be applied on the inner surface of the laminate. As a further alternative, the top layer may be secured to the flange by a patterned adhesive or similar attachment mechanism. A print layer (not shown) may be provided within the structure and other layers may be included or added. It is preferred that the top layer not include a paper, foil or metal layer.
(13) Schematically shown in
(14) Separation of the cuts for the various score line patterns within the overall pattern is contemplated to simplify the manufacturing process and the formation of the die-cutting rollers. Although two separate patterns are shown in the schematic process of
(15) Once the score pattern is completed within the surface of the film, the web is moved to be joined with the sealing flange. The receptacle substrate 12 is shown in rolled from 48. The cells 16 may be formed as part of the overall process or prior to the formation of the roll 48. The cells 16 in the substrate 12 are filled with product 20 at a filling station F and the open end of each hollow is brought into alignment with the top layer 14 at the heating station H (or similar station for securing the top layer to the substrate). The top layer 14 is sealed to the sealing flange (18) to close each cell 16 (and seal the product 20 therein). The combined web and substrate is cut and separated to define a package having the desired size and number of product filled cells.
(16) The schematic of
(17) It has been found that one desired quality of a blister package of the type shown (with a polymer top layer and a defined score pattern therein) relates to the force required for discharging product from a cell. A consistent push-through force is preferable within each blister package and similarly within a plurality of similarly formed blister packages. Hence, it is preferable that there be a minimum of deviation in discharging product from each cell.
(18) In one example, the blister package may be utilized for gum or other confection products. One desirable feature within this type blister package is a relatively low push-through force. It should be relatively easy to discharge the product from the cell. However, the required push-through force should be sufficient for the package to maintain its integrity during assembly, shipping and handling. Hence, the occurrence of accidental tearing of the top layer is preferably minimized.
(19) It is preferred that the score line pattern form in the top layer of the blister package have a consistent depth of cut across the cell and across multiple cells. In addition, in the assembly of the package, the position of the score pattern is preferably formed in registration with the cell opening for consistency of the linear length of the score lines and the number and position of the score line intersections. Additional factors that may affect the consistency of the required push-through force may includebut not be limited tothe strength of the polymer top layer, the thickness of the layer, the tension in the web during the scoring operation or sealing operation, and the heat generated during scoring and sealing.
(20) The parameters of a consistent push-through force are defined by empirical testing of various score line patterns. Generally, it is desirable to have a relatively large number of linear inches of score lines in the overall pattern covering the open portion of the cell. In addition, a relatively large number of intersections within the score line formation generally provides consistent push-through results.
(21) In evaluating various score patterns for a blister package covering layer, a testing device may be utilized having a probe that moves against a secured film or web to simulate the push-through force for discharging a product from a blister receptacle. The test film/web is retained by a fixture that simulates a grid of receptacles within a blister package. The fixture secures the film/web in a manner similar to the securing of the film/web to a sealing flange of the blister package. The fixture divides the film/web into separate cells having dimensions corresponding to the cell of a blister receptacle. The probe is connected to equipment that measures the force applied by the probe when placed in contact with the film/web portion. The probe moves at a constant rate in a single transverse direction, applying a force to the web/film, until the film/web material within the test cell fails. Failure of the film/web results when the probe punctures or breaks through the material, simulating the push-through discharge of the product (such as a gum pellet or similar object). The probe is moved in a pattern across the grid of simulated cell cover portions, measuring the push-through force at a plurality of cells. The data from the plurality of cells is then analyzed for average push-through force and for consistency of the results.
(22) The push-through test results for various score patterns within a polymer film material may be compared to a standard or control force. For example, the results obtained from a testing device for a scored polymer film may be compared to the test results for a typical aluminum foil material, such as a foil for covering a gum package. This material is normally 0.0011 inches thick. It has been found that such a typical foil web requires a range of 4 to 8 lbs for push-through of the product from with the receptacle hollow.
(23) In
(24) In the graph of
(25) The Current pattern and Option A both result in an average push-through force in the range of the foil control or target range of 4-8 lbs. However, the deviation in the push-through force is recognizably higher in considering the test data in the Current pattern verses the Option A pattern. This higher deviation in the current pattern typically means that the force required in any given cell opening may exceed the target range. It is concluded from the data that an increase in the linear inches of the score pattern, in addition to an increase in the number of line intersections, provides advantageous, more consistent results.
(26) The Option B pattern includes a two-opposing pattern of chevron shaped lines. The chevrons appear to form apex points. Each chevron is relatively closely spaced with adjacent chevron lines. The total linear length of score lines is increased to 6.24 inches, corresponding to a score line to cell area ratio of about 13.3. In addition, as represented by the graph in
(27) The pattern labeled Option C shows a series of crossed straight lines combined with a pattern having rows of circles. As shown, the straight line pattern creates a crossed X with intersections within the straight line patterns. The X formation intersects with four circles formed in two rows over the cell openings. The X lines may be formed by a single die-cutting roller or the portions of the X may be separated on two rollers, with a third roller providing the circle pattern. Another method of formation may include one die-cutting roller having a first pattern with one half of the X pattern and a set of two circles adjacent thereto. The second roller would create the same pattern in mirror image, with the two rollers combining to create the total pattern illustrated. In the graph in
(28) The pattern example labeled Option D includes a straight line pattern overlapping rows of aligned curves. The curves are spaced relatively closer than those shown in the Current example and the Option A example. Three straight or lineal lines are included in the pattern, two intersecting the curves and one straight line formed between the curves. In
(29) The Option E example includes a plurality of circles, in varying sizes, and a series of angled straight lines. The circles are aligned in rows with a straight line preferably aligned and intersecting the circles. As shown, each straight line is transverse to and intersects with two side edges of each circle. In
(30) Option F provides a series of concentric circles with angled, parallel straight lines.
(31) Option G includes a series of parallel straight lines combined with a series of zig-zag lines. The zig-zag lines create a diamond shape that is traversed by intersecting straight lines. This Option G is an example of a score line pattern that may provide relatively consistent results for push-through force despite a shifting of the two line pattern positions or a shifting of the overall pattern relative to the cell position.
(32) In Option H, there is shown an overlap pattern of offset circles. The position of the circle rows creates an edge overlap in 4 places, with 8 intersections. In
(33) A useful blister package may be formed with a polymer top layer secured to the blister tray sealing flange having a score pattern formed in at least one surface and overlapping the cell. The score pattern is provided for promoting propagation of a tear in the top layer upon application of a transverse force of the product within the blister cell against the portion of the top layer overlapping the cell. In the above examples, a monolayer of polyester (0.0012 inches thick) was utilized. The score lines were targeted to cut into the film at 70% of the film thickness. This target cut depth was normally accepted in a range of plus or minus 10%. This structure and the identified score line patterns were then compared to the target foil push-through force. The various score patterns discussed herein may have multiple applications, including such examples as pharmaceuticals, soap tablets, etc. A relatively large push through force may be desirable in some applications. Variations in the top layer material, the thickness of the top layer, and the depth of cut may be incorporated into the various applications.
(34) In comparing the various score line embodiments shown, the patterns identified as Options A, Option D, Option F and Option G were found to provide consistent results as compared to the target range for push-through. Based the empirical data and observation, these score pattern will create positive push-through force results. These score line patterns include a total of at least 5 inches of linear score lines per cell or a score line to cell area ratio of at least 10.6. Moreover, the results were found to further improve when the score line linear length exceeded 6 inches or a score line to cell area ratio exceed 12.8. Further, these preferred score line lengths and ratio numbers are coupled with a number of line intersections in the pattern. The preferred number of score line intersections is at least 10, and preferably exceeding 12.
(35) As for Options B, C and E, the results were affected by registration of the two score line patterns during formation of the overall pattern on the polymer web and further by the form of the score lines. For example, the relatively sharp apex of the chevrons of Option B has a tendency to form an inconsistent cut in the polymer web. A variation of this pattern, with a rounded apex is contemplated to resolve this separate issue, while meeting the preferred linear length and intersection parameters defined. Options C and E were found to be affected by registration issues between the X and crossing line patterns with the circles. Positional variations affected the depth of cut in addition to varying the number of intersections and overall linear length of score lines within the cells tested. Elimination of the registration complications is contemplated to remove inconsistencies within the push-through measurement. With respect to Option H, the low number of intersections resulted in relatively inconsistent push-through results. (Registration issues also affected the testing results, independent of the intersection limitation issue.)
(36) The line pattern options shown and described illustrate that variations in the form of the line patterns and the density of the lines each affect the total linear length of the score lines in the cells and a total number of intersections. These two parameters are not necessarily proportional; hence, the same result may not occur if there is an increase in one number with a corresponding reduction in the other. Further, line patterns different from those shows may produce desirable results. As noted above, selection of a pattern that is relatively simple may affect the overall acceptability of the pattern, due to the preferred method of applying different portions of the overall score line pattern at different stations in the formation process. As noted, registration of the score line portions during the die-cutting operation (as an example) may affect performance results. A further factor in the selection of a score line pattern is the depth of cut. A consistent depth is desirable, although variations may be acceptable, depending on user requirements and the line pattern selected.
(37) In the drawings and specification, there has been set forth a number of embodiments of the invention and, although specific terms are employed, these terms are used in a generic and descriptive sense only and not for purposes of limitation. The scope of the invention is set forth one or more of the claims.