U.S. patent application number 10/307464 was filed with the patent office on 2003-04-24 for laminated board for enhanced graphics packaging and strength.
Invention is credited to Brown, William L., Fu, Thomas Z., Koukoulas, Alexander A., Sammarco, Timothy S..
Application Number | 20030077470 10/307464 |
Document ID | / |
Family ID | 26906417 |
Filed Date | 2003-04-24 |
United States Patent
Application |
20030077470 |
Kind Code |
A1 |
Sammarco, Timothy S. ; et
al. |
April 24, 2003 |
Laminated board for enhanced graphics packaging and strength
Abstract
The invention relates to a laminated board grade structure used
for low cost, enhanced graphics packaging. The product contains an
unbleached or bleached substrate board and pigmented opaque polymer
film applied to the unbleached board substrate to produce a product
with a smooth coated, glossy surface for quality graphics
printing.
Inventors: |
Sammarco, Timothy S.;
(Cornwall, NY) ; Fu, Thomas Z.; (Milford, OH)
; Brown, William L.; (Mason, OH) ; Koukoulas,
Alexander A.; (Ridgewood, NJ) |
Correspondence
Address: |
Stewart L. Gitler, Esq.
HOFFMAN, WASSON & GITLER, PC
Suite 522
2361 Jefferson Davis Highway
Arlington
VA
22202
US
|
Family ID: |
26906417 |
Appl. No.: |
10/307464 |
Filed: |
December 2, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10307464 |
Dec 2, 2002 |
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09875253 |
Jun 7, 2001 |
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60211739 |
Jun 15, 2000 |
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Current U.S.
Class: |
428/507 ;
428/535; 428/537.1 |
Current CPC
Class: |
B32B 27/10 20130101;
Y10T 428/3188 20150401; Y10T 428/31989 20150401; Y10T 428/266
20150115; Y10T 428/31993 20150401; Y10T 428/31978 20150401; Y10T
428/24942 20150115; Y10T 428/273 20150115; Y10T 428/31982 20150401;
B32B 27/20 20130101; Y10T 428/277 20150115; Y10T 428/31902
20150401; Y10T 428/31906 20150401; Y10T 428/31899 20150401 |
Class at
Publication: |
428/507 ;
428/535; 428/537.1 |
International
Class: |
B32B 023/08 |
Claims
What is claimed is:
1. A laminated board structure for enhanced graphics packaging
comprising: a paperboard substrate; and a pigmented opaque polymer
film applied directly to the substrate board.
2. The laminated board structure as claimed in claim 1, wherein the
board structure yields a Sheffield smoothness of 100-350 SU and a
final Parker print surface smoothness from 1.5-4.0 microns when
measured using a pressure of 10 kgf/cm.sup.2.
3. The laminated board structure as claimed in claim 1, wherein the
board structure yields a GE brightness of 60-90 and a 75.degree.
gloss level of 35-75%.
4. The laminated board structure as claimed in claim 1, wherein the
board structure yields 70-160 ft-lbf. of internal bond
strength.
5. The laminated board structure as claimed in claim 1, wherein the
pigmented opaque polymer film is applied to the substrate board by
extrusion, or by hot melt adhesion.
6. The laminated board structure as claimed in claim 1, wherein the
paperboard substrate has a thickness ranging from 7 to 30 mils and
a basis weight range of 25-96 lbs./1000 sq. ft.
7. The laminated board structure as claimed in claim 1, wherein the
paperboard substrate has a Sheffield smoothness of 200-400 SU and
Parker print surface smoothness of less than 12 microns when
measured using a pressure of 10 kgf/cm.sup.2.
8. The laminated board structure as claimed in claim 1, wherein the
paperboard substrate is a multi-ply white top linerboard or a
mottled white linerboard for improved opacity and/or whiteness in
the final structure.
9. The laminated board structure as claimed in claim 1, wherein the
polymer pigmented opaque is repulpable and/or biodegradable for
improved recycling or environmental degradation.
10. The laminated board structure as claimed in claim 1, wherein
the pigmented opaque polymer film layer is pigmented by titanium
dioxide, calcium carbonate, talc, clay, pearlescent pigments,
colored pigments or combinations thereof.
11. The laminated board substrate as claimed in claim 1, wherein a
coat weight of the pigmented opaque polymer film layer applied by
extrusion ranges from 9-35 lbs./3,000 sq. ft.
12. The laminated board substrate as claimed in claim 1, wherein a
coat weight of the hot melt applied pigmented opaque polymer film
layer ranges from 3-10 lbs./3,000 sq. ft.
Description
[0001] Applicant claims the benefit of priority provisional patent
application Serial No. 60/211,739, filed May 15, 2000, and patent
application Ser. No. 09/875,253, filed Jun. 7, 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a laminated board product
that can be converted into containers for carrying canned or
bottled beverages or for various folding carton applications. More
particularly, the final product has sufficient wet strength
properties for use as the beverage carrier, or carrier board,
product mentioned above. The laminate board product is repulpable
and recyclable.
[0003] U.S. Pat. No. 5,882,746 discloses a laminated paperboard
package that is produced by initially printing graphics by high
speed printing on a sheet of clay-coated publication paper. The
pre-printed paper is then continuously applied to the surface of a
cellulosic substrate and bonded to the substrate, preferably
through the use of starch as an adhesive, to provide a laminated
product. This structure has several disadvantages in that there is
no ability to print beverage carrier designs on existing print
stations that are set up for printing heavy boards which are
characteristic of beverage carriers. In addition, some printing
presses are equipped to cut the printed material into cartons in an
on-line after printing procedure. A pre-printed paper laminated to
a board would require an additional cutting operation for such
printing presses. This pre-printed concept is essential to the
patent's disclosure and clearly distinguishes same from the subject
matter contained herein.
[0004] It is an objective of the present invention to produce a
final product that has sufficient wet strength properties even
though the original paper and/or paperboard components do not have
wet strength additives in them.
[0005] It is also an objective of the invention to have a structure
that allows for lower coat weights on the coated sheet and still
allow one to get the desired opacity compared to standard clay
coated unbleached grades.
[0006] It is a further object of the present invention to produce a
laminated board grade that can be used for beverage carriers and/or
unbleached or bleached folding carton applications.
SUMMARY OF THE INVENTION
[0007] The product produced from the laminated board structure of
the present invention, includes as a paperboard substrate,
unbleached or bleached board, containing either Kraft, groundwood,
thermomechanical (TMP), chemithermomechanical (CTMP), bleached
chemithermomechanical (BCTMP), and/or recycled fiber. Laminated to
the board substrate is a lightweight coated or uncoated, unprinted,
white, paper which, if coated, is coated on one, or two sides. This
produces a product with a smooth unprinted surface for high quality
graphics post-printing. Lamination can occur either by standard
adhesive (aqueous-based, solvent-based, or UV-cured) lamination,
pasting methods, use of an extruder, or through a hot melt
application system.
[0008] As a variation, a pigmented (white or color) opaque polymer
film can be coated onto the substrate board, see FIG. 2, using an
extrusion or hot melt process. The pigment can be titanium dioxide,
calcium carbonate, talc, clay, pearlescent pigments, colored
pigments or combinations thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts a cross-section of a preferred embodiment of
a laminated board structure embodying the present invention;
[0010] FIG. 2 depicts an alternate embodiment of a cross-section of
a laminated board structure embodying the present invention;
and
[0011] FIG. 3 depicts an alternate preferred embodiment of a
cross-section of a laminated board structure embodying the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 depicts a cross-section of a laminated board
structure 10 which comprises a board substrate 12 which is
preferably paperboard, either unbleached or bleached, containing
either Kraft, groundwood, thermomechanical, chemithermomechanical,
bleached chemithermomechanical, and/or recycled fiber. A
lightweight coated or uncoated unprinted white paper grade 16
which, if coated, can be coated on one, or two sides, is laminated
to the substrate 12 via various methods. Lamination can occur by
standard adhesive lamination using an adhesive 18 as depicted in
FIG. 1, by pasting methods, by use of an extruder, or by use of a
hot melt system. An extruder, hot melt, or UV-cured adhesive system
is preferred, since they do not add moisture to the paper
components, which tends to induce curl in the final product. Also,
extrusion and/or hot melt systems produce a continuous polymer,
water barrier film for enhanced wet strength performance. For hot
melt lamination, a polymer resin coat weight as low as 1 lb/3,000
ft.sup.2 could be used with a sprayed hot melt system. Heavier coat
weights ranging from 9 to 35 lbs/3,000 ft.sup.2 may be used with a
slot die on an extruder/hot melt system to increase caliper and/or
final product strength. A chill roll may or may not be used after
the two components are laminated together to impart a desired
finished appearance. Further, the resin for adhesive, extrusion, or
hot melt applications can be biodegradable to make environmentally
friendly substrates or containers. The finished laminated board
structure has the following properties: Sheffield smoothness of
100-350 Sheffield units (SU) as measured by TAPPI test method T538
om-96, Parker print surface smoothness (TAPPI Test Method T555
om-94) from 1.5-4.0 .mu.m when measured using a pressure of 10
kgf/cm.sup.2, GE brightness of 60-90 (TAPPI test method T452
om-98), 75.degree. gloss of 35-75% (TAPPI test method T480 om-99),
and internal bond strength of 70-160.times.10.sup.3 ft.-lbf (TAPPI
test method T833 pm-94).
[0013] The lamination adhesives can include an aqueous-based
adhesive such as ethylene vinyl acetate (EVA) at a solids coat
weight of 1-8 lbs./1000 sq. ft., an ultraviolet (UV) light cured
adhesive, and an ion-beam cured adhesive (or other electromagnetic
radiation cured adhesive). Also, an EVA-based or UV-cured
pressure-sensitive adhesive (PSA) can be used for lamination.
Lastly, a chemical fragrant or perfume can be added to the adhesive
to impart an attractive odor to the finished carton.
[0014] In extrusion or hot melt lamination, an extruded
polyethylene layer or a hot melt film comprised of ethylene vinyl
acetate (EVA) can be used among others.
[0015] The substrate board 12 can vary in thickness depending upon
the performance needs of the end use. For example, the thickness
may vary from 7 mils for lightweight folding carton applications,
to 32 mils for heavyweight carrier board applications, with a basis
weight range of 25-96 lbs./1000 sq. ft. The smoothness of the
paperboard substrate ranges from 200-400 Sheffield smoothness and
less than 12 microns Parker print surface when measured using a
pressure of 10 kgf/cm.sup.2.
[0016] The board substrate 12 does not necessarily need to have wet
strength chemicals incorporated into it to achieve a wet strength
that is acceptable for carrier board applications as long as the
polymer based adhesive is water insoluble once cured. The polymer
layer 18 produced by the lamination process offers a barrier to
liquid penetration into the sheet and helps bind the structure
together. Liquids can weaken the paper 12 and board substrate 12.
Additionally, the polymer layer also offers added strength to the
end product. For improved opacity and/or whiteness, a whitetop
linerboard or a mottled white linerboard can be used for the
substrate.
[0017] The top sheet 16, see FIG. 3, can be uncoated, coated on one
side 18, or coated on two sides 19, and 20. The top sheet 16 is
bleached and typically has a low basis weight and a low caliper,
namely approximately 80 lbs/3,000 ft.sup.2 or less, with a
preferred embodiment of 40 lbs./3000 sq. ft. or less, and 6.0 mils,
or less, with a preferred embodiment of 3.5 mils or less.
[0018] The coating 19 on the coated, lightweight unprinted white
bleached paper can contain combinations of clay, titanium dioxide,
and calcium carbonate to achieve desired smoothness, opacity, and
brightness. These coatings produce a Sheffield smoothness less than
100 SU, a Parker print surface less than 2.0 .mu.m when measured
using a pressure of 10 kgf/cm.sup.2, a GE brightness of 60-90%, and
an unprinted gloss of 35-75% on the unprinted, coated paper.
Colored or pearlescent pigments may also be added to add visual
appeal for packaging applications. Alternatively, a highly-filled,
bleached, uncoated, supercalendered (SC) paper or other uncoated
paper grade may be used in place of a coated paper.
[0019] As a variation, a pigmented (white or color) opaque polymer
film 40 can be coated onto the substrate board 12, see FIG. 2,
using an extrusion or hot melt process. The pigment can be titanium
dioxide, calcium carbonate, talc, clay, pearlescent pigments,
colored pigments or combinations thereof. This will allow the board
substrate to achieve a stronger barrier layer against moisture and
will improve the tear resistance of the board. Additionally, this
polymer coating offers added visual appeal by enhancing whiteness,
print gloss, smoothness, and uniqueness. Further, the resin for
extrusion or hot melt coating can be reputable and/or biodegradable
to make environmentally friendly substrates or containers if so
desired. The traditional carrier board is made using wet strength
chemicals, which adds cost and makes the product very difficult to
repulp and/or recycle.
[0020] Lastly, an ink jet coating layer 45 may also be added onto
the top surface in order to prepare the laminated or extrusion/hot
melt coated product for ink jet printing applications, for
packaging. The ink jet coating 45 may be added using standard
coating techniques that include, but are not limited to, coating
with a gravure cylinder, blade coating, rod coating, curtain
coating, or spray coating. This coating step may be done on line
during lamination and/or extrusion/hot melt coating operations, or
may be done off line as a separate operation. Alternatively, an ink
jet media can be laminated onto paperboard by one of the lamination
procedures described earlier.
[0021] As an alternative, or variation, an uncoated, unprinted,
lightweight, white paper could be utilized in place of the
unprinted lightweight, coated, white paper. This unprinted,
uncoated paper has the following properties: basis weight up to 80
lbs./3000 sq. ft., with a preferred embodiment of 30 lbs./3000 sq.
ft. or less, and a thickness of 6.0 mils or less, with a preferred
embodiment of 3.5 mils or less. The uncoated sheet could be
printed, as is, or could be coated on line during the lamination
and/or printing operations, using a gravure cylinder and/or a spray
coating method to add a coating or a pre-print varnish. It is
important to note that the bleached top sheet is not pre-printed
prior to lamination. This is essential to the invention. The
adhesive 18 can be either an aqueous based, solvent based, a hot
melt, an extruded polymer, or a UV or ion-beam cured adhesive.
Further, the resin for adhesive and coating applications can be
biodegradable to make environmentally friendly substrates or
containers.
[0022] As an alternative, the lightweight-coated paper described
earlier can also be replaced by a lightweight-coated Bristol board
grade with a caliper greater than 6 mils. The Bristol grade is
bleached and coated on one or two sides with titanium dioxide,
calcium carbonate, talc, clay, pearlescent pigments, colored
pigments, or combinations thereof. This coated Bristol grade
consists of bleached fibers and has a Sheffield smoothness less
than 100 SU and a Parker print surface smoothness less than 2.0
.mu.m when measured using a pressure of 10 kgf/cm.sup.2.
[0023] The lamination procedure provides a laminated board
structure, which is an economical alternative to current structures
in the marketplace. The curl often produced from aqueous based
lamination processes or aqueous adhesives can be minimized or
eliminated by use of a backside moisturization system (spray or
cylinder application). A chemical fragrant or perfume can also be
added to the moisturization water to impart an attractive odor to
the finished carton.
[0024] Alternatively, by using hot melt or extruded adhesives, the
curl often produced from aqueous based lamination
processes/adhesives can be minimized or eliminated relative to
other adhesives such as aqueous adhesives and/or starch based
adhesives. Furthermore, heavyweight multi-layered coatings of up to
three layers can be eliminated thereby producing a product that is
economical. Expensive components such as titanium dioxide are not
necessary to produce the particular product, but can be used for
enhanced brightness, opacity, and/or visual appeal.
[0025] Numerous modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that within the scope of the appended
claims, the invention may also be practiced otherwise than as
specifically described herein.
* * * * *