U.S. patent application number 13/902771 was filed with the patent office on 2013-12-19 for film and sheet for folding packaging containers.
The applicant listed for this patent is Thomas Inglis. Invention is credited to Thomas Inglis.
Application Number | 20130337206 13/902771 |
Document ID | / |
Family ID | 37463744 |
Filed Date | 2013-12-19 |
United States Patent
Application |
20130337206 |
Kind Code |
A1 |
Inglis; Thomas |
December 19, 2013 |
FILM AND SHEET FOR FOLDING PACKAGING CONTAINERS
Abstract
A film of biodegradable polylactic acid polymers (PLA) and
copolymers are produced by biaxially orienting single and
multilayer extrusions. The film and sheets are stiff, have
excellent optical properties and show excellent retained folding
and creasing properties making them especially desirable for the
production of folded box like containers. The surface layer(s) of
the film and sheet may be heat sealable or modified with a particle
to give improved coefficient of friction (COF), blocking
resistance, reduced static generation, improved winding and
improved package formation on packaging machines.
Inventors: |
Inglis; Thomas; (Wingham,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Inglis; Thomas |
Wingham |
|
CA |
|
|
Family ID: |
37463744 |
Appl. No.: |
13/902771 |
Filed: |
May 24, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11442441 |
May 30, 2006 |
|
|
|
13902771 |
|
|
|
|
Current U.S.
Class: |
428/36.4 |
Current CPC
Class: |
B32B 7/02 20130101; B32B
27/16 20130101; B32B 27/20 20130101; B32B 1/08 20130101; Y10T
428/1352 20150115; B32B 2264/0207 20130101; Y10T 428/1372 20150115;
B32B 2307/518 20130101; B32B 2307/406 20130101; B32B 2307/554
20130101; B32B 2307/746 20130101; Y10T 428/24942 20150115; B65D
1/40 20130101; B32B 2439/62 20130101; B32B 27/36 20130101; B32B
2264/025 20130101; B32B 27/18 20130101; B32B 2250/40 20130101; B32B
2307/412 20130101; B32B 2307/4026 20130101; B32B 27/08 20130101;
B32B 2307/544 20130101; B32B 2250/244 20130101; B32B 2307/581
20130101; B32B 2307/7163 20130101; B32B 2307/704 20130101; B32B
2439/40 20130101 |
Class at
Publication: |
428/36.4 |
International
Class: |
B65D 1/40 20060101
B65D001/40 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2005 |
CA |
2508859 |
Claims
1. A high clarity container produced from a bi-axially oriented
heat stable composite film of from 4 to 30 mils thickness which has
been stretched in both the machine direction and transverse
direction by a ratio of 2 to 6 times consisting essentially of, an
inner layer of polylactic acid with a first and second surface and
attached to one or both of said first and second inner layer
surfaces one or more additional skin layers of the same or
different polylactic acid resins as the inner layer, at least one
of the skin layers containing spherical particles for the purpose
of reducing the coefficient of friction (COF) of the composite
film, the container produced by folding or creasing combined with
sealing or gluing along at least one edge or between two surfaces
to create a sealed container.
2. A high clarity container produced from film according to claim
1, by folding or creasing and sealing or gluing along an edge with
a folding and reclosable flap on at least one surface of the
container for the purpose of gaining access to the interior of the
package.
3. A folding thermoformed high clarity container from a bi-axially
oriented heat stable composite film of from 4 to 30 mils thickness
which has been stretched in both the machine direction and
transverse direction by a ratio of 2 to 6 times consisting
essentially of, an inner layer of polylactic acid with a first and
second surface and attached to one or both of said first and second
inner layer surfaces one or more additional skin layers of the same
or different polylactic acid resins as the inner layer, the skin
layers containing spherical particles for the purpose of reducing
the coefficient of friction (COF) of the composite film, with a
hinged fold for repetitive opening and closing of the container in
conjunction with a means for sealing or holding the container in a
closed configuration.
4. The high clarity container of claim 1 wherein the polylactic
acid skin layers are of the same polymer as the inner layer.
5. The high clarity container of claim 1 wherein the skin layers
are of a lower melting polylactic acid composition than the inner
layer.
6. The high clarity container of claim 1 wherein the skin layers
are of a lower crystallinity than the inner layer.
7. The high clarity container of claim 1 wherein one skin layer is
of a different polylactic acid composition than the other skin
layers.
8. The high clarity container of claim 1 wherein one skin layer
does not contain the spherical particles.
9. The high clarity container of claim 1 wherein the spherical
particles are a crosslinked polymethylsilsesquioxane particles.
10. The high clarity container of claim 1 wherein the spherical
particles are a crosslinked acrylic resin particles.
11. The high clarity container of claim 1 wherein the spherical
particles are composed of a polymeric substance.
12. The high clarity container of claim 1 wherein the spherical
particles are present in a range of from 0.01% to 0.5% (100 to 5000
ppm) by weight of the polylactic acid of the skin layer.
13. The high clarity container of claim 1 wherein one or both first
and second inner layer surfaces are subjected to corona, flame or
plasma treatment.
14. The high clarity container of claim 1 wherein at least one
intermediate skin layer is added between the inner layer and outer
skin layers.
15. The high clarity container of claim 1 wherein intermediate skin
layers are attached to the first surface and second surface of the
inner layer and located between the inner layer and outer skin
layers.
16. The high clarity container of claim 15 wherein at least one of
the intermediate skin layers are colored with a transparent
dye.
17. The high clarity container of claim 1 wherein the inner layer
is colored with a transparent dye.
18. The high clarity container of claim 1 wherein at least one of
the skin layers are colored with a transparent dye.
Description
FIELD OF THE INVENTION
[0001] This invention relates to the production and use of oriented
multilayered biodegradable films with improved dead fold, crease
retention, a hinging action, excellent optical properties,
coefficient of friction (COF), flavor and aroma barrier and reduced
blocking and static generation. In particular it relates to
multilayered biodegradable mono or biaxially oriented polylactic
acid films and sheets for use in packaging articles in die cut and
folded containers or tubular containers or with formed and hinged
clam shell packaging, or as lid stock and the like. The films are
heat and ultrasonic and solvent sealable.
DESCRIPTION OF THE RELATED ART
[0002] High quality products such as perfume, liquors, jewelry,
confectionary products, and the like are beneficially displayed in
high clarity box like containers consisting of folded polymers,
tubular containers or clam shell hinged containers which have
replaced highly printed paperboard containers. However, existing
polymers such as PVC, polystyrene and polyolefins when used to
replace the paperboard containers give up the composting behavior
of the paper board and are considered by some to be less desirable
environmentally. This is especially true when the high clarity
replacement is produced from chlorine containing polymers such as
polyvinyl chloride (PVC), polyvinylidene chloride (PVDC) or their
copolymers. In some locations the use of these high clarity
chlorinated packaging materials are not legally permitted, severely
limiting the choice of alternatives for high clarity folding
containers. In addition many of the alternative materials such as
styrene based materials are brittle and require heat for folding
and the fold is not extremely durable and therefore, unsuitable as
a hinge requiring a large amount of flexing as in opening and
closing of the container. Also if the more flexible polymers are
chosen, they generally have poorer optical properties and stiffness
such as the propylene based materials. Other materials, if modified
to make them flexible and more durable, have the tendency to stress
whiten when bent, creased or flexed due to the toughing mechanisms
of the polymers. These problems are readily overcome by the use of
a multilayer, oriented polylactic acid film or sheet ranging from 4
to 25 mils in thickness.
[0003] Polylactic acid is a biodegradable or compostable polymer
produced from the condensation polymerization of lactic acid. The
monomer used for the production of polylactic acid is available in
two optically active isomers, the D-Lactic acid and the L-lactic
acid. The relative amounts of the two isomers when combined
together and polymerized yield various polymers with different
crystallinity (amorphous to semicryatalline), crystallization
behavior and melting points. Polymers of this type are available
from Cargill-Dow and are represented by the commercial polymer
grades, PLA4042 and PLA4060. Both resins are produced by the
combination of the two optical isomers of lactic acid, the L-lactic
acid and the D-lactic acid in different ratios. The relative ratio
of the two isomers controls the final crystallinity and
crystallization behavior of the polymers which result in polymers
with varying physical and thermal properties.
[0004] When the commercially available polylactic acid polymers
(PLA) are coextruded and biaxially stretched, the films produced
have excellent dead fold, fold durability when flexed, optical
clarity and gloss. When the films and sheets are in the thickness
range of 4 mils to 25 mils they display an excellent folding
property where a scored or unscored bend, crease or fold is made.
The folded film or sheets are both durable and flexible displaying
a hinge like action on multiple folding and a permanent fold which
readily holds it position when flexed. In addition, the fold shows
little or no voiding or "stress whitening" typical of other
toughened polymers used in these applications. These properties
makes it especially attractive for the manufacture of high clarity
folded display cartons such as are currently manufactured with PVC,
amorphous polyester, polypropylene, polypropylene copolymers,
polystyrene and impact modified polystyrene and the like. The film
and sheet is especially suitable for replacing existing clear box
materials with an improved folding performance as well as for
replacing card board or paper products in tubular or clam shell
containers where the clarity of the new film or sheet is desired
and the composting ability of the polylactic acid does not detract
from the environmental concerns of the paper board replacement with
the polymers.
[0005] U.S. Pat. No. 4,447,479 discloses packaging applications
using polypropylene based products.
[0006] U.S. Pat. No. 6,743,490 B2 discloses a lamination of a PLA
film to a thick paper and relates to a packaging box for a golf
ball, and more particularly to a packaging box which can be
decomposed completely when it is disposed into the ground in
consideration of environmental protection, looks fine, and is not
damaged easily to allow the packaging box to have a high function.
The packaging box makes use of a combination of thick paper and PLA
films where the PLA film is used to give a folded window in the box
while the majority of the container is opaque due to the presence
of the paper laminated to the film. The PLA film is biaxially
oriented.
[0007] The use of slip modified outer layers also permit the slip
modification of the PLA films and sheets to improve the performance
of unmodified or single layer PLA films or sheets. In general
unmodified PLA films or sheets demonstrate poor surface slip
properties as defined by the coefficient of friction (COF) and
result in poor film roll quality and in poor registration and
stacking in cut and stack applications and as a result are prone to
surface scratching when processed or when passed over stationary
equipment parts as found on converting and packaging machines. In
addition excessive forces are required to pull film products
through the packaging machines leading to film breakage wrinkles
and creases. In addition thin films produced with skins of
unmodified lower crystallinity PLA 4060 show a pronounced tendency
to block in roll or stack form especially when surface treated such
as by corona, flame or plasma treatment methods common in the film
industry. Aside from the blocking the formation of well formed
rolls both in winding on the orienter and in rewinding and slitting
is very difficult. This tendency towards poor roll formation and
blocking leads to excessive film loss and poor manufacturing
efficiencies especially with thin PLA films below 4 mils in
thickness. However, it has been observed that three layer
coextruded films produced above 4 mils and especially above 7 mils
using the high crystallinity PLA4042 resin and without slip
modification can be used without too much trouble.
[0008] The use of antiblock particles to improve film performance
is widely known and in the case of single layer films the
incorporation of additives must be in the entire thickness of the
polymer. This has several disadvantages in that the antiblock
particles are surface agents designed to control the contact area
of two adjacent film layers or between the film surface and
adjacent surfaces such as metal or rubber covered rollers on
processing equipment and therefore the benefit of a large portion
of the particles are lost due to their incorporation in the inside
of the film away from the surface. Therefore larger quantities of
antiblocking particles must be used than are required for the
improvement in surface properties. This results in an increased
cost for the antiblock particles and will limit the use of
expensive but highly effective additives such as the spherical
crosslinked silicones such as Tospearl or crosslinked acrylic
spheres such as Epostar. In addition, the use of additional non
functional particles in the core will increase the amount of light
scattering as measured as the film haze and reduce the value and
aesthetic appeal of the film as it impacts the ability to display
the packaged product.
[0009] There still remains a need for multilayer coextruded films
or sheet comprised of biodegradable polylactic acid copolymers with
improved folding, creasing and folded hinge durability, excellent
optical clarity and are of high gloss while displaying improved COF
and scuff resistance when wound or cut and stacked as sheets.
SUMMARY OF THE INVENTION
[0010] The invention is related to the production of multilayer
coextruded films or sheet of from 4 to 30 mils thick comprised of
various commercially available biodegradable polylactic acid
copolymers with improved folding, creasing and folded hinge
durability. The films also display an excellent optical clarity and
are of high gloss while displaying improved COF and scuff
resistance when wound or cut and stacked as sheets.
[0011] The films and sheets are of high clarity and gloss and are
scuff resistant, stiff and durable and may be die cut, folded and
sealed, welded or glued into containers for a range of products.
The boxes produced may contain flap type openings with a hinge like
fold for easy entry and reclosing of the container for ready access
to the product. In addition the films and sheets may be
thermoformed and folded to produce clam shell containers with a
well formed and durable hinge suitable for multiple opening and
reclosing.
DESCRIPTION OF THE INVENTION
[0012] The present invention provides for a PLA film which is
relatively thick (4 to 30 mils), biaxially oriented and may be
coextruded with identical skin and core polymers (equivalent to a
monolayer film or sheet), or with heat sealable skins to aid in the
sealing of the container by adhesive, ultrasonic, solvent or
thermal welding as well as having slip modified surfaces to improve
the handling and scuff resistance of the container while
maintaining high clarity and gloss of the unmodified film and
sheet. The film and sheet products may be wound into rolls or
sheeted and may be used in die-cutting and folding applications as
well as in the production of tubular containers and for
thermoforming applications to produce clam shell containers with
hinged lids. The films of the present application provide packaging
and other products which do not require the lamination to a
relatively thick paper and are used alone without lamination
simplifying the manufacture of the packaging.
[0013] The present application also provides for the production of
multilayer films where surface active antiblock particles can be
added to the surface layers alone and which place the particles
where they are most useful while reducing significantly the amount
of additive required lowering the cost of the film. In addition the
total haze of the film may be significantly reduced due to the
lower light scattering induced by the absence of scattering
particles from the core.
[0014] The use of lower melting surface copolymers of polylactic
acid permit the containers to be edge sealed or glued or welded as
in paper board carton manufacture. The PLA film and sheet surfaces
can be adhered to themselves or to the inside and outside layers of
the film or sheet by adhesive, heat or ultrasonic and solvent
welding to produce high strength bonds to form a high strength
container. Single layer films are readily sealed with ultrasonic
and solvent welding methods. The sealing method used can be
selected to produce a high clarity seals if so desired.
[0015] The invention is a coextruded, biodegradable film comprising
a core layer of polylactic acid copolymer and at least one
additional layer and as many as four additional layers of
polylactic acid copolymer of the same or lower melting point from
that of the core, and preferably a three layer film or sheet of
from 4 to 30 mils in thickness. In addition the films may also be
slip modified such that to at least one of the outermost skin layer
may be added an antiblock particle generally known in the art such
as a spherical particle produced from crosslinked
polymethylsilsesquioxane with a particle size ranging from 2 to 10
micrometer in diameter and in an amount ranging form 0.05% to 0.6%
by weight of the skin layer and preferably from 0.1 to 0.3% by
weight of the skin layer. The relative thicknesses of the core and
surface layers are chosen such that the final surface skin layer
thickness after stretching may vary from 1 to 68 microns and
preferably from 3 to 25 microns regardless of the final film
thickness
[0016] The multilayer film may be produced by sequential or
simultaneous orientation with a tenter frame process common to the
industry and well known in the art. In the particular case of a
sequential orientation the following steps are outlined.
[0017] The individual layers of the film are produced by melting
the polymers individually in separate extruders, adding the
particles to the polymer feed to the extruder, and mixing and
dispersing in the polymer during the melting of the polymer. The
individual layers are filtered to insure melt cleanliness without
removing the added particles and combined in a multicavity die. (It
should be understood by those skilled in the art that the
multilayer melt combination can also be done with a coextrusion
feedblock or combined in a coextrusion feedblock and a multicavity
die in combination). As the multilayer melt is extruded from the
die it is cast directly against a chilled chromed casting roll or
alternatively, it may be forced against a chilled chromed casting
roll with the use of a pinning mechanism well known in the art such
as electrostatic pinning, an air knife, a vacuum box, an additional
nip cooling roll or a combination of methods such as an air knife
and electrostatic edge pinning. However it is formed, the cast film
is cooled by the casting roll to set the molecular structure of the
skin and core for subsequent orientation.
[0018] On removal from the casting section, the cast sheet is
transported to the machine direction orienter at a uniform speed
where it is contacted with a series of heated rolls and reheated to
the drawing temperature. The heated sheet is then passed between
two rolls, the second of which is driven at a speed higher than the
first, to stretch the film in the axial or machine direction. This
machine direction stretching speed ratio (MDX) may range from 2 to
6 times and preferably from 2.5 to 4 times. The MD stretched film
is then cooled after stretching on additional heat transfer rolls
and transferred to a tenter for transverse (TD) orientation.
[0019] The TD orientation is accomplished by stretching in a heated
oven consisting of preheat, stretching and annealing sections. The
stretching is performed between two continuous rails in which
travel a continuous chain with clips designed for gripping the
edges of the MD stretched sheet. In the preheat section the rails
are approximately parallel and at the approximate width of the MD
stretched sheet. The rails then diverge forcing the chains apart
and stretching the film restrained in the clips. This TD stretching
can be from 2 times to 6 times the initial width of the chain
separation and preferably from 2.5 to 4 times. The rails are then
made parallel at the end of the stretching section at the final
width and the film is heated at a temperature suitable for
crystallizing and annealing the film while restrained in the clips.
This crystallization and annealing will reduce the shrinkage of the
film when reheated and the conditions chosen to give the desired
shrinkage of the film in subsequent converting operations. If
desired the chain separation may be reduced slightly to improve the
dimensional stability of the film as is well known in the art. The
rails then exit the oven and the film is quenched in air before
being released from the clips.
[0020] Upon release, the stretched film is passed to a thickness
scanning station to measure the thickness uniformity of the film.
Die adjustments either in a manual or automatic mode may be made to
improve the uniformity of the thickness as required or desired. The
stretched film then has its edges slit off to remove the remaining
thick regions where it was held by the clips and the trim is then
ground for reuse. If desired, the ground trim may be added directly
back into the film making process or pelletized in a separate
operation and added back into the film making process or resold for
other purposes. The film is then passed thru a web handling system
and may be subjected to a surface treatment step on one or both
sides and is then alternatively wound up on master or mill rolls
for subsequent slitting, or may be cut into various sized sheeting
and stacked for use in various converting processes.
[0021] The 4 to 30 mil films and sheets produced show an unexpected
folding and crease retention behavior which makes the product
especially desirable for die cutting and folding into high clarity
containers and other products such as presentation cards including
gift cards and certificates. The folded containers may have a
reclosable lid due to the excellent fold flex durability. The films
also show an excellent haze and gloss values and display a low and
uniform COF off the line and do not require additional time or
temperature to reduce the COF.
[0022] It should be obvious that the folding behavior and slip
modification technology can be applied to films with additional
intermediate layers between the core and skins which are, clear,
dyed or pigmented, to create colored films or to add desirable
decorative effects to the film.
[0023] The following examples are an illustration of the present
invention, but the invention is not limited to the specific
examples.
EXAMPLE 1
[0024] An 8 mil, three layer film was produced by individually
extruding a major or inner layer (core) of PLA4042 and onto this
core extruding two additional unmodified surface layers of PLA4042.
The final skin thickness after stretching was approximately 2.5
mils. The three polymer flows were combined in a three cavity die
and cast onto a cooled chill roll. The sheet so produced was
transferred to a machine direction orienter (MDO) and reheated on
hot rollers set at from 55.degree.-70.degree. C. and preferably at
60.degree.-62.degree. C. The sheet was then stretched between two
rollers driven at different speeds with a speed increase of
approximately 3 times between the first and second rolls. The drawn
sheet was then passed over a series of cooling rollers and
transferred to a tenter frame for transverse stretching where it
was introduced into a set of clips located on parallel chains
traveling at a uniform speed with a uniform spacing and preheated
in a forced air oven at a temperature of 50.degree.-65 .degree. C.
Next the film was stretched 3 times in the transverse (TD)
direction by a divergence of the chains in the oven at a
temperature of 65.degree.-75.degree. C. and then annealed and
crystallized in a section of parallel or slightly converging chain
separation at approximately 135.degree. to 145.degree. C. and
preferably at 141.degree. C. to heat set the film and increase it
crystallinity and reduce its tendency to shrink on reheating. Next
the film was released from the clips and transferred to a film
gauging system to determine its thickness uniformity and then the
thickened edges remaining for the clips were slit and removed. The
film next passed through a surface treatment station and was
treated to a desired level to improve film processing and
conversion and wound into master rolls for subsequent slitting
operations. The 8-10 mil film or sheet) produced show a highly
desirable folding and crease retention behavior which makes the
product especially suitable for die cutting and folding into high
clarity containers. The folded containers may have a reclosable lid
due to the excellent fold flex durability. The film produced also
showed an excellent optical clarity and a surprisingly low tendency
towards scuffing and dust pick up.
EXAMPLE 2
[0025] An 8 mil, three layer film was produced by individually
extruding a major or inner layer (core) of PLA4042 and onto this
core extruding two additional surface layers of PLA4042 each
containing 0.2% by weight of the skin layer of a spherical particle
produced from crosslinked polymethylsilsesquioxane. The average
particle size was 2 micrometers (Tospearl 120A) and the final skin
thickness after stretching was from 0.8 to 1.5 microns. The three
polymer flows were combined in a three cavity die and cast onto a
cooled chill roll. The sheet so produced was transferred to a
machine direction orienter (MDO) and reheated on hot rollers set at
from 55.degree.-70.degree. C. and preferably at
60.degree.-62.degree. C. The sheet was then stretched between two
rollers driven at different speeds with a speed increase of
approximately 3 times between the first and second rolls. The drawn
sheet was then passed over a series of cooling rollers and
transferred to a tenter frame for transverse stretching where it
was introduced into a set of clips located on parallel chains
traveling at a uniform speed with a uniform spacing and preheated
in a forced air oven at a temperature of 50.degree.-65.degree. C.
Next the film was stretched 3 times in the transverse (TD)
direction by a divergence of the chains in the oven at a
temperature of 65.degree.-75.degree. C. and then annealed and
crystallized in a section of parallel or slightly converging chain
separation at approximately 135.degree. to 145.degree. C. and
preferably at 141.degree. C. to heat set the film and increase it
crystallinity and reduce its tendency to shrink on reheating. Next
the film was released from the clips and transferred to a film
gauging system to determine its thickness uniformity and then the
thickened edges remaining for the clips were slit and removed. The
film next passed through a surface treatment station and was
treated to a desired level to improve film processing and
conversion and wound into master rolls for subsequent slitting
operations. The 4 to 25 mil films and sheets produced show a highly
desirable folding and crease retention behavior which makes the
product especially suitable for die cutting and folding into high
clarity containers. The folded containers may have a reclosable lid
due to the excellent fold flex durability. The film produced also
showed excellent handling in sheeting and winding operations while
maintaining an excellent optical clarity and a surprisingly low
tendency towards scuffing and static generation and dust pick
up.
EXAMPLE 3
[0026] The film was prepared as in example 2 with the exception
that the antiblock particle was comprised of from 0.05-2.5% by
weight of the skin layer of a silica particle of 4-5 micron average
particle size. The 4 to 25 mil films and sheets produced show a
highly desirable folding and crease retention behavior which makes
the product especially suitable for die cutting and folding into
high clarity containers. The folded containers may have a
reclosable lid due to the excellent fold flex durability. The film
produced also showed excellent handling in sheeting and winding
operations but displayed a poor clarity evidenced by a increased
and objectionable haze level. There was no improvement in reducing
static generation and in reduced dust pick up.
EXAMPLE 4
[0027] The film was produced as in example 2 where both surface
layers were comprised of a heat sealable PLA 4060 copolymer and
containing 0.2% by weight of the skin layer of a 4.5 micrometer
diameter spherical particle produced from crosslinked
polymethylsilsesquioxane. The 4 to 25 mil films and sheets produced
show a highly desirable folding and crease retention behavior which
makes the product especially suitable for die cutting and folding
into high clarity containers. The folded containers may have a
reclosable lid due to the excellent fold flex durability. The film
produced also exhibited improved heat sealing, excellent handling
in sheeting and winding operations while maintaining an excellent
optical clarity and a surprisingly low tendency towards scuffing
and static generation and dust pick up. The film also has displayed
good hot slip and printability
EXAMPLE 5
[0028] The film of example 1 was die cut and folded and sealed
together along an extended edge flap to produce a box with an
operable hinged flap
EXAMPLE 6
[0029] The film of example 1 or 2 was die cut and folded and glued,
or ultrasonically or solvent welded together along an extended edge
flap to produce a box with an operable hinged flap
EXAMPLE 7
[0030] The film of example 1 was cut and rolled and edge sealed
together to produce a tube suitable for the display of products
when supplied with end caps or similar closures suitable for
tubular packaging.
EXAMPLE 8
[0031] The film of Example 1 was thermoformed into a hinged clam
shell folding container with various closure options generally
known to those skilled in the art
EXAMPLE 9
[0032] The film of example 4 was thermoformed into a hinged clam
shell or folding container for the purpose of holding and
displaying packaged items which is heat, ultrasonically or solvent
welded together along its edges or at discreet points to prevent
casual opening of the package
EXAMPLE 10
[0033] The film of example 1 was thermoformed into a hinged clam
shell or folding container for the purpose of holding and
displaying packaged items which is ultrasonically or solvent welded
together along its edges or at discreet points to prevent casual
opening of the package
EXAMPLE 11
[0034] The film of example 4 was die cut and folded and sealed
together along an extended edge flap to produce a box with an
operable hinged flap
EXAMPLE 12
[0035] The film of example 4 was cut and rolled and edge sealed
together to produce a tube suitable for the display of products
when supplied with end caps or similar closures suitable for
tubular packaging.
[0036] Various modifications to the process and film construction
will be apparent to and can be readily made by those skilled in the
art without departing from the scope and spirit of this invention.
Accordingly, it is not intended the scope of the claims appended
hereto be limited to the description as set forth herein, but
rather that the claims be broadly construed.
* * * * *