U.S. patent application number 15/578121 was filed with the patent office on 2018-10-25 for method for manufacturing a sleeved product.
The applicant listed for this patent is Fuji Seal International, Inc.. Invention is credited to Ernst Christian Koolhaas, Nao Yoshida.
Application Number | 20180304525 15/578121 |
Document ID | / |
Family ID | 54325626 |
Filed Date | 2018-10-25 |
United States Patent
Application |
20180304525 |
Kind Code |
A1 |
Yoshida; Nao ; et
al. |
October 25, 2018 |
METHOD FOR MANUFACTURING A SLEEVED PRODUCT
Abstract
A method of activating the shrink characteristic of a
multi-layered film (1), the method comprising the steps of
providing a multi-layered film comprising at least a base layer
film (2) that comprises a shrinkable film, and a photothermic layer
(3), associated with the base layer film, and comprising a
photothermic material, exposing the multi-layered film (1) to
electromagnetic radiation in order for the photothermic material to
generate heat and shrink the multi-layered film (1), wherein the
electromagnetic radiation comprises UV-light having a peak
wavelength between 200 nm and 399 nm, and at least 90% of the
UV-light is within a bandwidth of .+-.30 nm of the peak
wavelength.
Inventors: |
Yoshida; Nao; (EE Eindhoven,
NL) ; Koolhaas; Ernst Christian; (TT Nuenen,
NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fuji Seal International, Inc. |
Osaka Osaka-shi |
|
JP |
|
|
Family ID: |
54325626 |
Appl. No.: |
15/578121 |
Filed: |
May 26, 2016 |
PCT Filed: |
May 26, 2016 |
PCT NO: |
PCT/EP2016/061929 |
371 Date: |
November 29, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65B 53/02 20130101;
B29C 61/02 20130101; B32B 2325/00 20130101; B65B 53/00 20130101;
B32B 2307/736 20130101; B32B 27/302 20130101; B32B 27/08 20130101;
B29L 2031/7158 20130101; B32B 27/36 20130101; B32B 2439/60
20130101; B29C 63/42 20130101; B29C 63/40 20130101 |
International
Class: |
B29C 61/02 20060101
B29C061/02; B65B 53/00 20060101 B65B053/00; B29C 63/40 20060101
B29C063/40; B29C 63/42 20060101 B29C063/42; B32B 27/08 20060101
B32B027/08; B32B 27/36 20060101 B32B027/36; B32B 27/30 20060101
B32B027/30 |
Foreign Application Data
Date |
Code |
Application Number |
May 29, 2015 |
NL |
2014885 |
Claims
1. Method of activating the shrink characteristic of a
multi-layered film, the method comprising the steps of: providing a
multi-layered film comprising at least a base layer film comprising
a shrinkable film, and a photothermic layer, associated with the
base layer film, and comprising a photothermic material, exposing
the multi-layered film to electromagnetic radiation in order for
the photothermic material to shrink the multi-layered film; wherein
the electromagnetic radiation comprises UV-light having a peak
wavelength between 200 nm and 399 nm, and at least 90% of the
UV-light is within a bandwidth of .+-.30 nm of the peak
wavelength.
2. The method of claim 1, wherein the UV-light is emitted by a
LED-UV emitter.
3. The method of claim 1, wherein the UV-light has a peak
wavelength between 300 nm and 395 nm, more preferably between 350
nm and 390 nm.
4. The method of claim 1, wherein the base layer film is
substantially free from a photo-thermic material.
5. The method of claim 1, wherein the base layer film is a
multi-layered laminated base layer film.
6. The method of claim 1, wherein the photothermic layer is
provided in direct contact with the base layer film.
7. The method of claim 1, wherein the multi-layered film has a UV
absorption of at least 50%, calculated from transmittance and
reflectance as measured by ISO13468-2.
8. The method of claim 7, wherein the photothermic layer is
multi-layered and at least one of the photothermic layers has a UV
absorption of at least 50%, calculated from transmittance and
reflectance as measured by ISO13468-2.
9. The method of claim 1, wherein the multi-layered film comprises
a design layer, associated with the base layer film and/or the
photo-thermic layer, and comprising a colored ink composition.
10. The method of claim 9, wherein the design layer is the
photothermic layer.
11. The method of claim 9, wherein the design layer forms a pattern
of discontinuous regions, and the multi-layer film comprising a
base layer, a photothermic layer and a design layer is
substantially homogeneously shrunk independent from the
pattern.
12. The method of claim 9, wherein the photothermic layer and/or
the design layer is printed.
13. The method of claim 1, wherein the multi-layer film preferably
has a UV shrinkage of at least 15% in main shrinking direction as
obtained by exposure to UV light of 6.0 J/cm.sup.2.
14. The method of claim 1, wherein the base layer film preferably
has a UV shrinkage of less than 5% in main shrinking direction as
obtained by exposure to UV light of 6.0 J/cm.sup.2.
15. The method of claim 1, wherein the base layer film has a free
shrink in main shrinking direction of less than 10% after immersion
in water at 60.degree. C. for 10 sec.
16. The method of claim 1, wherein the photothermic layer comprises
a photothermic composition comprising one or more binder resins and
from 3 to 80 wt. % of the photothermic material relative to the
photothermic layer.
17. The method of claim 1, wherein the photothermic material
comprises UV-light absorbing material selected from (white)
titanium dioxide (TiO2); (black) carbon black; (cyan)
phtalocyanide; (magenta) quinacridone, diketopyrrolopyrrole,
naphtol-based azo pigment, anthraquinone; (yellow) aceto acetic
acid- and/or anhydride-based azo pigment; dioxiazine and
benzotriazole UV absorber, benzo triazole, benzo phenone,
salicylate, triazine and/or cyano acrylate type of UV absorber; and
combinations thereof.
18. The method of claim 16, wherein the photothermic composition of
the photothermic layer comprises a white ink composition,
comprising from 20 to 80 wt. % of titanium dioxide relative to the
photothermic layer.
19. The method of claim 1, wherein the photothermic composition of
the photothermic layer comprises a transparent lacquer composition
comprising a benzotriazol UV absorber.
20. A method for manufacturing a sleeved product, the method
comprising arranging a sleeve around the product, the sleeve
comprising a multi-layered film comprising at least a base layer
film comprising a shrinkable film, and a photothermic layer,
associated with the base layer film, and comprising a photo-thermic
material, exposing the sleeve to electromagnetic radiation in order
for the photothermic material to shrink the multi-layered film;
wherein the electromagnetic radiation comprises UV-light having a
peak wavelength between 200 nm and 399 nm, and at least 90% of the
UV-light is within a bandwidth of .+-.30 nm of the peak
wavelength.
21. The method of claim 20, wherein the sleeve is provided in a
flat form and wrapped around a mandrel, whereby two sleeve edge
parts to be sealed overlap and/or contact each other in a seam
area, and the edges are sealed to provide a tubular sleeve,
whereafter the sleeve is opened and ejected around the product.
22. The method of claim 20, wherein the sleeve is provided in a
flat form and wrapped around the product whereby two sleeve edge
parts to be sealed overlap and/or contact each other in a seam
area, and the edges are sealed to provide the sleeve.
23. The method of according to claim 20, wherein the sleeve is
provided in a preformed tubular form and arranged around the
product.
24. The method of claim 20, wherein at least one of the edge parts
does not comprise the photothermic layer in the seam area.
25. The method of claim 20, wherein the product has a substantially
cylindrical shape comprising a large diameter part and a smaller
diameter part, and the sleeve covers at least part of the large
diameter and smaller diameter part.
26. The method of claim 25, wherein the circumference of the
smaller diameter part is between 15-70% of the circumference of the
large diameter part.
27. The method of claim 20, wherein the electromagnetic radiation
comprises UV-light having a peak wavelength of 365 nm, 385 nm or
395 nm, wherein at least 75% of the UV-light is within a bandwidth
of 10 nm of the peak wavelength.
28. The method of claim 27, wherein the electromagnetic radiation
comprises UV-light having a peak wavelength of 365 nm or 385 nm,
wherein at least 90% of the UV-light is within a bandwidth of
.+-.10 nm of the peak wavelength.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of activating the
shrink characteristic of a multi-layered film, and a method for
manufacturing a sleeved product.
BACKGROUND
[0002] Shrinkable films are commonly used to label products such as
plastic containers or glass bottles.
[0003] Examples of products labelled with shrinkable films include
detergent bottles, milk and yoghurt containers, jam jars and
medicine bottles.
[0004] Shrinkable films, and in particular heat-shrinkable films,
are designed to contract or shrink when heated and, in doing so,
substantially conform to the shape of the product the film is being
used to label.
[0005] It is known to activate the shrink characteristic of a
heat-shrinkable film using steam and/or hot air, for example, by
carrying the label and product through a tunnel provided with steam
and/or hot air. US 2008/0197540 A1 for example discloses a
multi-layered film that may be shrunk around an item in a heat
tunnel using steam or hot air. However, there are some
disadvantages associated with using hot steam and/or hot air to
label products. For example, the hot steam and/or air may
undesirably heat a substance contained within the product. Also,
labels shrunk using hot steam and/or air often do not conform
completely to all of the contours of the product, especially if the
product has a complex shape.
[0006] It is also known to use UV light to shrink shrinkable films.
Such films typically comprise a material that is capable of
absorbing UV light. When the material absorbs the UV-light, heat
may be generated and it is this generated heat that causes the
shrinkable film to contract. US 2005/0142313 A1 for instance
discloses a method of shrinking a film that comprises the steps of
providing a shrink film and exposing the film to an amount of
radiation energy effective to activate the shrink characteristics
of the film. The film comprises single-walled carbon nanotube
material as photothermic material. The effective amount of
radiation energy may for instance comprise one or more of any of
visible light, infrared light, ultraviolet light, microwave and
radiowave.
[0007] Typical UV-emitting devices are known from US 2007/0235689
A1, US 2007/006924 A1, U.S. Pat. No. 4,859,903, EP 1067166 A2, and
US 2006/0138387 A1.
[0008] The present invention is directed towards an improved method
of activating the shrink characteristic of a multi-layered
film.
SUMMARY
[0009] The present invention provides a method of activating the
shrink characteristic of a multi-layered film, the method
comprising the steps of: [0010] providing a multi-layered film
comprising at least a base layer film that comprises a shrinkable
film, and a photothermic layer, associated with the base layer
film, and comprising a photothermic material, [0011] exposing the
multi-layered film to electromagnetic radiation in order for the
photothermic material to shrink the multi-layered film; [0012]
wherein [0013] the electromagnetic radiation comprises UV-light
having a peak wavelength between 200 nm and 399 nm, and [0014] at
least 90% of the UV-light is within a bandwidth of 30 nm of the
peak wavelength.
[0015] This method has the advantage of providing improved
shrinkage of the multi-layered film. For example, the method
produces more homogenous shrinkage of the multi-layered film.
[0016] The method of the present invention involves exposing the
film to UV light, where at least 90% of the UV-light that falls
within .+-.30 nm of the peak wavelength. This means that 90% of all
of the UV radiation used falls within a 60 nm range.
[0017] If the intensity of the UV light used in the method of the
present invention was to be plotted on a graph against the wave
length of the UV light, there would be a peak on this graph for the
peak wavelength. In addition, at least 90% of the total intensity
of the UV light would fall within .+-.30 nm of this peak on the
graph.
[0018] In some embodiments of the invention, the photothermic layer
comprises a white pigment suitable for absorbing UV light (for
example, titanium dioxide). For example, the photothermic layer may
be formed by printing an ink comprising the white pigment on to a
base layer film. Alternatively, the photothermic layer may be
formed by printing transparent lacquer comprising a UV absorber,
such as a benzotriazole that is capable of absorbing UV light.
Again, a transparent lacquer composition comprising said UV
absorber may be printed onto the base layer film.
[0019] In other embodiments, the photothermic layer may comprise
both a transparent lacquer composition, comprising a UV absorber,
and an ink composition (comprising a white pigment). For example,
if the multi-layered film also comprises a design layer and the
photothermic layer is provided on top of this design layer, the
photothermic layer may be formed from a transparent lacquer, and a
white ink composition may be provided below the design layer at its
back side in order to increase the contrast and brilliance of the
design layer.
[0020] In some embodiments at least 90% of the UV-light is within a
bandwidth of .+-.10 nm of the peak wavelength.
[0021] In preferred embodiment of the invention, the
electromagnetic radiation may comprise UV-light having a peak
wavelength of 365 nm, or 385 nm, or 395 nm, wherein at least 75% of
the UV-light is within a bandwidth of .+-.10 nm of the peak
wavelength.
[0022] In a more preferred embodiment, the electromagnetic
radiation may comprise UV-light having a peak wavelength of 365 nm
or 385 nm, wherein at least 90% of the UV-light is within a
bandwidth of .+-.10 nm of the peak wavelength.
[0023] Preferably, the UV-light is emitted by a LED-UV emitter.
[0024] The UV-light preferably has a peak wavelength between 300 nm
and 395 nm, more preferably between 350 nm and 390 nm. For example,
the peak wavelength may be 365 nm, 385 nm or 395 nm, with 365 nm
and 385 being preferred.
[0025] In preferred embodiments of the invention, the base layer
film is substantially free from a photothermic material. The base
layer film may be a multi-layered laminated base layer film.
Preferably, the base film comprises over 95% of a thermoplastic
resin.
[0026] With `substantially` is meant in the context of the present
application at least 90% of the indicated quantity, more preferably
at least 95% of the indicated quantity, and most preferably at
least 98% of the indicated quantity.
[0027] In embodiments of the invention, the photothermic layer may
be provided in direct contact with the base layer film. However, in
other embodiments, the photothermic layer may be provided in
indirect contact with the base film. For example, the photothermic
layer may contact the base film via an intermediate design
layer.
[0028] Preferably, the multi-layered film has a UV absorption of at
least 50%, calculated from transmittance and reflectance as
measured by ISO13468-2. The photothermic layer preferably has a UV
absorption of at least 50%, more preferably of at least 60%, most
preferably of at least 70%, calculated from transmittance and
reflectance as measured by ISO13468-2.
[0029] In some embodiments of the invention, the photothermic layer
is multi-layered and at least one of the photothermic layers has a
UV absorption of at least 50%, calculated from transmittance and
reflectance as measured by ISO13468-2.
[0030] Preferably, the multi-layered film comprises a design layer,
associated with the base layer film and/or the photo-thermic layer,
and comprising a colored ink composition. In some embodiments of
the invention, the design layer may be the photothermic layer.
[0031] Preferably, the design layer is continuous with the base
layer film and/or the photothermic layer. However, in some
embodiments, the design layer may form a pattern of discontinuous
regions, and the multilayer film comprising the base layer, the
photothermic layer and the design layer is substantially
homogeneously shrunk independent from the pattern. In this context,
`substantially` means at least 90% of the base layer film is shrunk
independent from the pattern. The photothermic layer may be
discontinuous but is preferably continuous.
[0032] Preferably, the photothermic layer and/or the design layer
is printed. A photothermic layer may be formed typically by coating
the base layer film, comprising the shrink film with a printing
ink. Coating of the base layer film is performed by a known or
common printing technique. The printing technique may be a common
technique and is preferably selected typically from gravure
printing and flexographic printing. The photothermic ink printed to
form the photothermic layer may comprise but is not limited to a
photothermic material, a binder resin, a solvent, and other
additives. The solvent is typically evaporated at least partly
after deposition of the ink on to the base layer film. This yields
a photothermic composition on the base layer film, which
photothermic composition then comprises a binder resin, the
photothermic material and the other additives. The solvent may be
selected from solvents generally used in printing inks, which are
exemplified by organic solvents such as toluene, xylenes, methyl
ethyl ketone, ethyl acetate, methyl alcohol, ethyl alcohol, and
isopropyl alcohol; and water.
[0033] The binder resin for use herein is exemplified by, but not
limited to, acrylic resins, urethane resins, polyamide resins,
vinyl chloride-vinyl acetate copolymer resins, cellulosic resins,
and nitrocellulose resins.
[0034] The photothermic material comprises a UV-light absorbing
material selected from (white) titanium dioxide (TiO2); (black)
carbon black; (cyan) phtalocyanide; (magenta) quinacridone,
diketopyrrolopyrrole, naphtol-based azo pigment, anthraquinone;
(yellow) aceto acetic acid- and/or anhydride-based azo pigment;
dioxiazine and benzotriazole UV absorber; and combinations thereof.
Each of the photothermic materials, binder resins, and solvents may
be used alone or in combination in each category.
[0035] In the photothermic composition, a white ink composition
comprising titanium dioxide is preferred. When a clear based design
is required, a transparent lacquer composition comprising a UV
absorber is preferably used as the photothermic composition.
[0036] The thickness of the photothermic layer may be selected
within wide ranges since the thickness is not particularly
critical. A thickness of the photothermic layer of from 0.1 to 10
.mu.m is particularly preferred however.
[0037] A design layer in accordance with some embodiments of the
invention is defined as a layer that indicates an item such as a
trade name, an illustration, handling precautions, and the like.
The design layer may be formed typically by coating the shrink film
with a colored ink. The coating is performed by a known or common
printing technique, and is preferably selected from gravure
printing and flexographic printing. The colored ink printed to form
the design layer may comprise but is not limited to a photothermic
material, a binder resin, a solvent and other additives. The binder
resin for use herein is exemplified by, but not limited to, acrylic
resins, urethane resins, polyamide resins, vinyl chloride-vinyl
acetate copolymer resins, cellulosic resins, and nitrocellulose
resins. Suitable pigments to be used in the design layer include
but are not limited to white pigments, such as titanium oxide
(titanium dioxide); indigo blue pigments, such as copper
phthalocyanine blue; and other coloring pigments such as carbon
black, aluminum flake, and mica. These pigments may be selected and
used according to an intended purpose. The pigment may also be
selected from extender pigments, typically used for gloss
adjustment. Suitable extender pigments include but are not limited
to alumina, calcium carbonate, barium sulfate, silica, and acrylic
beads. The pigment may work as photothermic material. The level of
potency is different depending on the pigment. The solvent may be
selected from solvents generally used in inks, which are
exemplified by organic solvents such as toluene, xylenes, methyl
ethyl ketone, ethyl acetate, methyl alcohol, ethyl alcohol, and
isopropyl alcohol; and water. Each of such pigments, binder resins,
and solvents may be used alone or in combination in each
category.
[0038] The design layer may have any thickness which is not
critical, but preferably ranges from 0.1 to 10 .mu.m.
[0039] The base layer film in accordance with the invention
comprises a shrinkable film. The shrinkable film for use in the
method comprises a layer that serves as a base of the label and
which bears strength properties and shrinking properties. One or
more thermoplastic resins for use in the shrinkable film may be
suitably selected typically according to required properties and
cost. Exemplary resins include, but are not limited to, polyester
resins, olefinic resins, styrenic resins, poly(vinyl chloride)s,
polyamide resins, and acrylic resins. The shrinkable film is
preferably made from a polyester film, a polystyrenic film, or a
multilayered laminated film of these films. Exemplary polyester
resins usable herein include poly(ethylene terephthalate) (PET)
resins, poly(ethylene-2,6-naphthalenedicarboxylate)s (PENs), and
poly(lactic acid)s (PLAs), of which polyethylene terephthalate)
(PET) resins are preferred. Preferred exemplary styrenic resins
include regular polystyrenes, styrene-butadiene copolymers (SBSs),
and styrene-butadiene-isoprene copolymers (SBISs).
[0040] The shrinkable film for use herein may be a single-layer
film, or a multilayered laminated film including two or more film
layers according typically to required properties and intended use.
When use is made of a multilayered laminated film, the multilayered
laminated film may include two or more different film layers made
from two or more different resins, respectively.
[0041] The shrinkable film is preferably a monoaxially, biaxially,
or multiaxially oriented film, so as to exhibit shrinking
properties. When the shrinkable film is a multilayered laminated
film including two or more film layers, at least one film layer of
the multilayered laminated film is preferably oriented. When all
the film layers are not or only slightly oriented, the shrinkable
film may not exhibit sufficient shrinkage properties. The
shrinkable film is preferably a monoaxially or biaxially oriented
film and is even more preferably a film substantially oriented in a
transverse direction or in a machine direction of the film. In
other words, the shrinkable film is preferably oriented
substantially monoaxially in a transverse direction or in a machine
direction. This direction of main orientation will preferably
coincide with a circumferential direction of a sleeve or ROSO
label.
[0042] The shrinkable film may be prepared according to a common
procedure such as film formation using a molten material or film
formation using a solution. Independently, commercially available
shrinkable films are also usable herein. Where necessary, the
surface of the shrinkable film may have been subjected to a common
surface treatment such as corona discharge treatment and/or primer
treatment. The lamination of the shrinkable film, in case of a
laminated structure, may be performed according to a common
procedure such as coextrusion or dry lamination. Orientation of the
shrinkable film may be performed by biaxial drawing in a machine
direction (MD) and in a transverse direction (TD) or by monoaxial
drawing in a machine or transverse direction. The drawing can be
performed according to any of roll drawing, tenter drawing, or tube
drawing. The drawing is often performed by conducting drawing in a
machine direction according to necessity and thereafter drawing in
a transverse direction each at a temperature of from about
70.degree. C. to about 100.degree. C. The draw ratio in the machine
drawing may be from about 1.01 to about 1.5 times, and preferably
from about 1.05 to about 1.3 times. The draw ratio in the
transverse drawing may be from about 3 to about 8 times, and
preferably from about 4 to about 7 times.
[0043] Though not critical, the thickness of the shrinkable film is
preferably from 10 to 100 .mu.m, more preferably from 20 to 80
.mu.m, and even more preferably from 20 to 60 .mu.m. The shrinkable
film may be a three-layer film including a core layer and surface
layers. In this case, the ratio in thickness among the core layer
and the surface layers [(surface layer)/(core layer)/(surface
layer)] is preferably from 1/2/1 to 1/10/1. In case a five-layer
shrinkable film is used, the ratio in thickness among the core
layer and the surface layers [(surface layer)/(core layer)/(surface
layer) is preferably from 1/0.5 to 2/2 to 10/0.5 to 2/1.
[0044] The shrinkable film may be shrunk or may not be shrunk in UV
light without the photothermic layer. The shrinkable film can be
shrunk well to combine to a photothermic layer. The percentage of
shrinkage in UV light of 6.0 J/cm.sup.2 (such as obtained by UV
light of a wavelength of 365 nm at 3.3 W/cm.sup.2, or a wavelength
of 385 nm at 5.5 W/cm.sup.2) of the shrinkable film in its main
direction of orientation is preferably less than 5%. Although not
critical, the percentage of thermal shrinkage of the shrinkable
film in its main direction of orientation is preferably less than
10% in hot water at 60.degree. C. for 10 seconds, more preferably
less than 10% in hot water at 70.degree. C. for 10 seconds, even
more preferably less than 10% in hot water at 80.degree. C. for 10
seconds, and most preferably less than 10% in hot water at
90.degree. C. for 10 seconds. When the shrinkable film has a
percentage of thermal shrinkage in its main orientation direction
exceeding the above preferred ranges, the stability of storage is
higher and the risk to shrink unnecessarily during transportation
is reduced. A further advantage of the present embodiments is
represented by a limited or even non-existing shrinkage at
atmospheric temperatures during transportation, Although not
critical, the percentage of thermal shrinkage in a hot glycerin
bath at 150.degree. C. for 10 seconds of the shrinkable film in its
main direction of orientation is preferably at least 30%. From the
viewpoint of accessibility, a shrinkable film having at least 40%
of thermal shrinkage in hot water at 90.degree. C. for 10 seconds
can also be chosen.
[0045] The percentage of shrinkage in UV light of 6.0 J/cm.sup.2
(such as obtained by UV light of a wavelength of 365 nm at 3.3
W/cm.sup.2, or a wavelength of 385 nm at 5.5 W/cm.sup.2) of the
base layer film in its main direction of orientation is preferably
less than 5%. Although not critical, the percentage of thermal
shrinkage of the base layer film in its main direction of
orientation is preferably less than 10% in hot water at 60.degree.
C. for 10 seconds, more preferably less than 10% in hot water at
70.degree. C. for 10 seconds, even more preferably less than 10% in
hot water at 80.degree. C. for 10 seconds, and most preferably less
than 10% in hot water at 90.degree. C. for 10 seconds. When the
base layer film has a percentage of thermal shrinkage in its main
orientation direction exceeding the above preferred ranges, the
stability of storage is higher and the risk to shrink unnecessarily
during transportation is reduced.
[0046] Although not critical, the percentage of thermal shrinkage
in hot glycerin bath at 150.degree. C. for 10 seconds of the base
layer film in its main direction of orientation is preferably at
least 30%. In point view of accessibility, the base layer film
having at least 40% of thermal shrinkage in hot water at 90.degree.
C. for 10 seconds also can be chosen.
[0047] The percentage of shrinkage of the multi-layer film in its
main direction of direction, as obtained by exposure to UV light of
6.0 J/cm.sup.2 (such as obtained by UV light of a wavelength of 365
nm at 3.3 W/cm.sup.2, or a wavelength of 385 nm at 5.5 W/cm.sup.2),
is preferably at least 15%, more preferably from 30% to 80%, and
even more preferably from 50% to 80%. This embodiment yields a
higher total shrinkage after the shrinkage treatment, which is
beneficial in sleeving irregularly shaped containers or bottles.
When the multilayer film has a percentage of shrinkage by UV light
in its main orientation direction exceeding the above preferred
ranges, the film when shrunk conforms substantially completely to
substantially all contours of the product to be sleeved, in
particular when the product has a complex shape.
[0048] Although not critical, the percentage of thermal shrinkage
of the multi-layer film in its main direction of orientation is
preferably less than 10% in hot water at 60.degree. C. for 10
seconds, more preferably less than 10% in hot water at 70.degree.
C. for 10 seconds, even more preferably less than 10% in hot water
at 80.degree. C. for 10 seconds, and most preferably less than 10%
in hot water at 90.degree. C. for 10 seconds. When the multi-layer
film has a percentage of thermal shrinkage in its main orientation
direction exceeding the above preferred ranges, the stability of
storage is higher and the risk to shrink unnecessarily during
transportation is reduced.
[0049] Although not critical, the percentage of thermal shrinkage
in hot glycerin bath at 150.degree. C. for 10 seconds of the
multi-layer film in its main direction of orientation is preferably
at least 30%. From the point of view of accessibility, a
multi-layer film having at least 40% of thermal shrinkage in hot
water at 90.degree. C. for 10 seconds can also be chosen.
[0050] As used herein the term "main orientation direction" refers
to a direction in which the drawing process of the shrinkage film
has been mainly performed (i.e., a direction in which the
percentage of thermal shrinkage is largest) and, when the
shrinkable label is a tubular shrinkable label, the main
orientation direction will generally be in a width direction of the
film.
[0051] The percentage of shrinkage of the multi-layered film in a
direction perpendicular to the main orientation direction by
exposure to UV light of 6.0 J/cm.sup.2 (365 nm at 3.3 W/cm.sup.2;
or 385 nm at 5.5 W/cm.sup.2) is preferably from about -10% to about
50%, more preferably from -10% to 20%, and most preferably from -5%
to 10%, or from -5% to 3%, although these percentage are not
critical.
[0052] The transparency of the shrinkable film for use in
embodiments wherein the shrinkable film is a transparent film, is
preferably less than 15.0, more preferably less than 10.0, and most
preferably less than 5.0, in terms of haze (%) determined in
accordance with ISO14782. The shrinkable film, when having a haze
of 15 or more, may cloud a print and thereby cause insufficient
decorativeness when the print is to be seen through the shrinkable
film. If the haze of the shrinkable film is within the preferred
ranges, it may be possible in some embodiments to print on the
backside.
[0053] In some embodiments, the base layer film may have a stretch
ratio (ST ratio) of at least three in one or more directions.
[0054] The multi-layer film preferably has a UV shrinkage of at
least 15% in main shrinking direction as obtained by exposure to UV
light of 6.0 J/cm2.
[0055] The base layer film preferably has a UV shrinkage of less
than 5% in main shrinking direction as obtained by exposure to UV
light of 6.0 J/cm2.
[0056] The base layer film has a free shrink in main shrinking
direction of less than 10% after immersion in water at 60.degree.
C. for 10 sec.
[0057] In some embodiments, the photothermic layer may comprise a
photothermic composition comprising one or more binder resins and
from 3 to 80 wt. % of the photothermic material relative to the
weight of the photothermic layer.
[0058] The photothermic material may comprise UV-light absorbing
material selected from (white) titanium dioxide (TiO2); (black)
carbon black; (cyan) phtalocyanide; (magenta) quinacridone,
diketopyrrolopyrrole, naphtol-based azo pigment, anthraquinone;
(yellow) aceto acetic acid- and/or anhydride-based azo pigment;
dioxiazine and benzotriazole UV absorber, benzo triazole,
benzophenone, salicylate, triazine and/or cyano acrylate type of UV
absorbers; and combinations thereof.
[0059] In embodiments of the invention, the photothermic
composition of the photothermic layer may comprise a white ink
composition, comprising from 20 to 80 wt. % of titanium dioxide
relative to the weight of the photothermic layer. Alternatively or
additionally, the photothermic composition of the photothermic
layer may comprise a transparent lacquer composition comprising a
benzotriazol UV absorber.
[0060] Exemplary UV absorbers or organic photothermic materials
include compounds in the benzophenone type of UV absorbers, such as
2-Hydroxy-4-methoxy benzophenone (e.g., Cyasorb UV 9) and
2-hydroxy-4-octoxy benzophenone (e.g., Cyasorb 531 and CibaR
CHIMASSORBR 81). Other exemplary UV absorbers include compounds in
the benzotriazole type of UV absorbers, such as
2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole,
2-(2H-hydroxy-3-5-Di-tert-amyllphenyl)benzotriazole,
2-2-hydroxy-5-tert-octylphenyl) benzotriazole,
2-(2H-hydroxy-3-5-di-tert-butylphenyl)benzotriazole,
2-(2-hydroxy-5-methyl phenyl) benzotriazole, and
2-[2-hydroxy-3,5-di-(1,1-dimethylbenzyl)phenyl]-2H-benzotriazole.
Yet other exemplary UV absorbers include p-aminobenzoic acid
(PABA), avobenzone, 3-benzylidene camphor, benzylidene camphor
sulfonic acid, bisymidazylate, camphor benzalkonium methosulfate,
cinoxate, diethylamino hydroxybenzoyl hexyl benzoate, diethylhexyl
butamido triazone, dimethicodiethylbenzal malonate (Parsol SLX),
dioxybenzone, drometrizole trisiloxane, ecamsule, ensulizole,
homosalate, isoamyl p-methoxycinnamate, 4-methylbenzylidene
camphor, menthyl anthranilate, octocrylene, octyl dimethyl PABA,
octyl methoxycinnamate, octyl salicylate, octyl triazone,
oxybenzone, PEG-25 PABA, polyacrylamidomethyl benzylidene camphor,
sulisobenzone, bisethylhexyloxyphenol methoxyphenol triazine (e.g.,
Tinosorb S), methylene bis-benzotriazolyl tetramethylbutylphenol
(e.g., Tinosorb M), and trolamine salicylate.
[0061] According to a second aspect of the present invention there
is a method for manufacturing a sleeved product, the method
comprising arranging a sleeve around the product, the sleeve
comprising a multi-layered film comprising at least a base layer
film comprising a shrinkable film, and a photothermic layer,
associated with the base layer film, and comprising a photo-thermic
material, [0062] exposing the sleeve to electromagnetic radiation
in order for the photothermic material to shrink the multi-layered
film; [0063] wherein [0064] the electromagnetic radiation comprises
UV-light having a peak wavelength between 200 nm and 399 nm, and
[0065] at least 90% of the UV-light is within a bandwidth of +30 nm
of the peak wavelength.
[0066] Preferably, the sleeve is provided in a flat form and
wrapped around a mandrel, whereby two sleeve edge parts to be
sealed overlap and/or contact each other in a seam area, and the
edges are sealed to provide a tubular sleeve, whereafter the sleeve
is opened and ejected around the product.
[0067] The sleeve is preferably provided in a flat form and wrapped
around the product whereby two sleeve edge parts to be sealed
overlap and/or contact each other in a seam area, and the edges are
sealed to provide the sleeve. Alternatively, the sleeve may be
provided in a preformed tubular form and arranged around the
product.
[0068] Preferably, at least one of the edge parts does not comprise
the photothermic layer in the seam area. This provides reduced
shrinkage of the film in the seam area and results in stronger
bonding strength between the edge parts.
[0069] In some embodiments, the product may have a substantially
cylindrical shape comprising a large diameter part and a smaller
diameter part, and the sleeve covers at least part of the large
diameter and smaller diameter part. In these embodiments, the
circumference of the smaller diameter part may be between 15-70% of
the circumference of the large diameter part.
BRIEF DESCRIPTION OF THE FIGURES
[0070] The accompanying figures are used to illustrate non-limiting
exemplary embodiments of the present invention.
[0071] FIG. 1A is a schematic view of a cross section through a
first embodiment of a multi-layered film of the present
invention;
[0072] FIG. 1B is a schematic view of a cross section through a
second embodiment of a multi-layered film of the present
invention;
[0073] FIG. 1C is a schematic view of a cross section through a
third embodiment of a multi-layered film of the present
invention;
[0074] FIG. 1D is a schematic view of a cross section through a
fourth embodiment of a multi-layered film of the present
invention;
[0075] FIG. 1E is a schematic view of a cross section through a
fifth embodiment of a multi-layered film of the present
invention;
[0076] FIG. 1F is a schematic view of a cross section through a
sixth embodiment of a multi-layered film of the present
invention;
[0077] FIG. 2 is a schematic view of a cross section through a
seventh embodiment of a multi-layered film of the present
invention;
[0078] FIGS. 3A to 3C are a front view and two cross-sectional
views of an eighth embodiment of a multi-layered film of the
present invention;
[0079] FIG. 4 shows a bottle that has been provided with a shrink
sleeve comprising the multi-layered film of FIGS. 3A to 3C;
[0080] FIGS. 5A to 5C show cross-sections of three further
embodiments of a multi-layered film of the present invention in a
seaming area; and
[0081] FIGS. 6A and 6B show perspective views of method steps in
the manufacturing of a sleeved product in accordance with
embodiments of the invention.
DESCRIPTION OF EMBODIMENTS
[0082] All of FIGS. 1A to 3 illustrate embodiments of multi-layered
films configured to be shrunk by the method of activating the
shrink characteristic of a multi-layered film of the present
invention.
[0083] In FIGS. 1A and 1B, the multi-layered film 1 comprises a
base layer film 2 and a photothermic layer 3. The layer 3 may also
be a photothermic layer in case only one color is used. The layer 3
is a combined photothermic and design layer when more than one
color is used such that a design may be noted. In FIG. 1A, the
combined photothermic and design layer 3 has been printed on top of
the base layer film 2, whereas in FIG. 1B, combined photothermic
and design layer 3 has been printed below the base layer film 2. In
FIGS. 1A to 3, a bottom or lower side of the film is defined as a
side of the film that faces or touches a product surface when
applied onto said product, whereas a top or upper side of the film
relates to a side of the film that faces a UV light source when
irradiated.
[0084] In FIG. 1A, the combined photothermic and design layer 3 may
be formed from a transparent lacquer. As well as having good UV
absorption properties, this transparent lacquer may provide a
protective layer. This is because when the film 1 of FIG. 1A is
fitted around a product, it is the base layer film 2 that will be
in contact with the product, and the combined photothermic and
design layer 3 will form the top layer of the film 1.
[0085] The combined photothermic and design layer 3 of the film 1
of FIG. 1B may also be formed from a transparent lacquer. However,
in contrast to the first embodiment, it is the combined
photothermic and design layer 3 of this second embodiment that will
come into contact with a product. Therefore, in addition to
providing good UV absorption, this embodiment protects the combined
photothermic and design layer 3 against scratching.
[0086] Alternatively, the combined photothermic and design layer 3
of the embodiment of FIGS. 1A and 1B may be formed from coloured
inks, for example, black and white inks, where these inks also have
good UV absorption properties.
[0087] In FIGS. 1C to 1F, the multi-layered film 1 is provided with
separate photothermic and design layers 4, 5.
[0088] In the embodiment of FIG. 1C, the film 1 is provided with a
photothermic layer 4 provided directly below the base layer film 2,
and a separate design layer 5 provided on the photothermic layer 4.
With this embodiment, the photothermic layer 4 may also comprise a
transparent lacquer that has good UV absorption properties.
Preferably, the photothermic layer 4 will act as a binder between
the base layer film 2 and the design layer 5.
[0089] FIG. 1D illustrates an embodiment of the invention
comprising a photothermic layer 4 provided on the upper surface of
the base layer film 2 and a design layer 5 provided on the lower
surface of the base layer film 2. In this embodiment, the
photothermic layer 4 may once again be formed from a transparent
lacquer that has good UV absorption properties. As the lacquer is
provided on top of the base layer film 2, the photothermic layer 4
will form the outer layer of the film 1 and so, preferably, the
lacquer additionally provides a protective coat for the film 1.
[0090] In addition, in FIGS. 1C and 1D, the design layer 5 forms
the lowermost layer of the film 1. This means, therefore, that both
the photothermic layer 4 and the base layer film 2 should be
transparent so that the design can be seen when it is viewed
through both the photothermic and base layer film (4, 2).
[0091] In all of the embodiments of FIGS. 1A to 1D, the layer
comprising the photothermic material (either the photothermic layer
4 or the combined photothermic and design layer 3) is provided
directly on the base layer film 2.
[0092] In contrast, in the embodiments of FIGS. 1E and 1F, the
photothermic material is provided in a photothermic layer 4 that is
in indirect contact with the base layer film 2. In other words, in
the embodiments of FIGS. 1E and 1F, the design layer 5 lies between
the base layer film 2 and the photothermic layer 4.
[0093] In FIG. 1E, the film 1 is provided with a base layer film 2
as the outmost layer. A design layer 5 is then provided on the
lower surface of this base layer film 2, and a photothermic layer 4
is provided below the design layer 5. In this embodiment, the
photothermic layer 4 could comprise a transparent lacquer or
coloured inks (such as black and white ink). Both the lacquer and
the coloured inks would have good UV absorption properties.
[0094] In the embodiment of FIG. 1F, the photothermic layer 4 and
the design layer 5 are both provided on the upper surface of the
base layer film 2. In particular, in this embodiment, the design
layer 5 is sandwiched between the photothermic layer 4 and the base
layer film 2. As the design layer 5 is positioned below the
photothermic layer 4, the photothermic layer 4 must be transparent
(for example, a transparent lacquer) or the design would not be
visible.
[0095] As the photothermic layer 4 is provided on an exposed
surface of the film 1 in both of FIGS. 1E and 1F, this layer 4 can
once again act as a protective layer. In the embodiments of FIGS.
1E and 1F, the photothermic layer 4 is protecting the design layer
5.
[0096] The embodiment of FIG. 2 shows a film 1 comprising a
combined photothermic and design layer 3 and a base layer film 2
comprising a multi-layered laminated film formed from five separate
layers 2a, 2b, 2c, 2d, 2e. The multi-layered laminated film may
have any number of layers, preferably three or five. The base layer
film 2 comprising a multi-layered laminated film in the present
embodiment comprises a core layer 2c of polystyrene (PS), two
middle layers (2b, 2d) of a blend of polyethylene terephthalate
(PET) and polystyrene (PET/PS), and two surface layers (2a, 2e) of
polyethylene terephthalate (PET).
[0097] FIG. 3A shows a front view of a multi-layered film 10
provided with a design. As shown in FIGS. 3B and 3C which
respectively show a cross-section according to lines B-B' and A-A',
the film 10 comprises a base layer film 12, a photothermic layer 14
and a design layer 15. The horizontal direction (B-B' direction) is
the direction of main orientation. The photothermic layer 14 in
this embodiment comprises a white ink composition 14a and a
transparent lacquer composition 14b that includes a photothermic
material, while the design layer 15 comprises a plurality of
colored ink compositions comprising a pigment. The printed colored
ink compositions (15a, 15b, 15c, . . . ) together define the design
as best shown in FIG. 3A. The UV absorption and shrinkage of each
of the printed colored ink compositions (15a, 15b, 15c, . . . ) are
different depending on the used pigment in the printed colored ink
compositions (15a, 15b, 15c, . . . ). Even if the multi-layer film
10 is comprised of partial design layers (15a, b, c) including
different pigments, the complete area covered and not covered by
design layers 15 can be shrunk and will not show a substantial
difference of shrinkage ratio, because the multi-layer film 10 has
a photothermic layer 14 that covers the complete area of the base
layer film 12. As shown in FIG. 3C, a top and bottom end of the
film 10 has a transparent area comprising a photothermic layer
formed by a transparent lacquer composition.
[0098] As shown in FIG. 3B, this photothermic layer 14 and the
design layer 15 do not extend over the complete width 16 of the
film 10 but leave some free area in which a seaming area 17a is
applied for seaming in a next step. Seaming is performed by
wrapping the film 10 around a product such that one end section
(seaming area 17a) of the film 10 that is, for the purpose,
provided with solvent or adhesive is brought in contact with
another seaming area 17b at another end of the film 10, in
accordance with arrow 11 and both seaming areas (17a, 17b) pressed
against each other to provide the seam. It is noted that the
seaming areas (17a, 17b) and the arrow 11 are shown to explain the
relationship to the next step, but are not part of the
cross-section of FIG. 3B. The arrangement shown makes it clear that
shrinkage of the seaming area 17a can occur since a photothermic
layer 14 is present in area 17b, even though the seaming area 17a
is substantially free of photothermic material.
[0099] Referring to FIG. 4, the film 10 when shrunk by a UV-light
source forms a tight sleeve 18 around the product, which in the
embodiment shown in FIG. 4 is a bottle 19, having a large diameter
part 19a and a smaller diameter part 19b, a top part with a cap
19c, and a bottom part 19d. The bottom part 19d may also be
provided with a shrunk film 10 if desired. In the sleeved
configuration shown in FIG. 4, the photothermic layer 14 of white
ink faces the outer surface of the bottle 19, while the base layer
film 12 faces outside towards a radiation source for shrinking the
sleeve. The method of the invention allows to tightly shrink a film
10 around a bottle 19 having large and small diameter parts (19a,
19b).
[0100] FIGS. 5A to 5C show yet other embodiments of a multi-layered
film 1 that may be subject to shrinkage in accordance with the
invented method. The film 1 comprises a base layer film 2 and a
printed layer 3, the latter comprises a design layer 31 and a
photothermic layer 32. The base layer film 2 has an end part 22
that defines a seaming area 29 having a first end 29a and a second
end 29b, as has already been explained above in the context of
FIGS. 3A to 3C. In an overlapping arrangement, end part 22 is
brought in line with other end part 21 of base layer film 2 and
adhesively bonded in area 29. The embodiment of FIG. 5A has a
backing print only, in that the design and photothermic layers (31,
32) are provided on a backside of the film 1 only. The embodiment
of figure SA is formed after seaming the embodiment shown in FIG.
1E. The backside of the film 1 is the side facing a sleeved product
surface. In the embodiment of figure SA, the photothermic layer 32
in end part 22 overlaps with the photothermic layer 32 in other end
part 21.
[0101] The embodiment of FIG. 5B has the design layer 31 printed on
the backside, and the photothermic layer 32 printed on a surface
side of the film 1. The embodiment of FIG. 5B is formed after
seaming the embodiment shown in FIG. 1D. The surface side of the
film 1 is the side facing away from a sleeved product surface, or,
alternatively, facing towards a UV-light source during a shrinkage
treatment. The embodiment of FIG. 5C finally has a combined
design/photothermic layer (31, 32) printed on the backside, and a
photothermic layer 32' printed on a surface side of the film 1. In
the embodiments of FIGS. 5A and 5C, the photothermic layer 32
covers substantially the complete area around the seaming area 29
in a circumferential direction 36. In the embodiment of FIG. 5B,
there is a small gap 35 which is not covered by the photothermic
layer 32, and therefore is not or less subject to shrinkage. Given
the small width of the gap 35 in a circumferential direction 36,
this is not much of a problem, because the main shrinking direction
corresponds to the circumferential direction 36.
[0102] FIGS. 6A and 6B finally disclose possible method steps in
embodiments of the invented method. The method for manufacturing a
sleeved product 40 comprises arranging a sleeve label 41 around a
product, which, in the embodiment shown is a bottle 39. The sleeve
41 comprises an embodiment of a multi-layered film (1, 10) as shown
in FIGS. 3 and 5. The sleeve 41 is arranged around the bottle 39
and then exposed to electromagnetic radiation emitted by a
plurality of UV LED sources 44. The photothermic material present
in the film (1, 10) generates heat and shrinks the multi-layered
film (1, 10). As claimed, the electromagnetic radiation comprises
UV-light having a peak wavelength between 200 nm and 399 nm, and at
least 90% of the UV-light is within a bandwidth of 30 nm of the
peak wavelength.
[0103] The sleeve 41 may be provided in a preformed tubular form,
the sleeve 41 being cut from an elongated preformed sleeve 410 of
the multi-layered film (1, 10) at a pitch 43 in a transverse
direction 42 to the axis of the sleeve 41. The circumferential
direction of the sleeve 410 corresponds to the main orientation and
main shrinkage direction.
[0104] In an alternative embodiment, the sleeve 41 is provided in
the form of a flat film 50 and a piece of the flat film 50 is cut
in a transverse direction 53 to a longitudinal axis of the flat
film 50, and then wrapped around a cylindrical mandrel 51 that is
rotated in a circumferential direction 52 of the mandrel 51. An
edge part of the cut flat film 50 is provided with a strip of
adhesive 54 which bonds two overlapping edge parts of the flat film
50 to provide the tubular sleeve 41. A machine direction of the
flat film 50 corresponds to the main shrinkage and circumferential
direction 52.
[0105] To arrange the sleeve 41 around the bottle 39, the sleeve 41
is slightly opened and ejected around the bottle 39 in a direction
55. The sleeve 41 is then exposed to electromagnetic radiation
emitted by a plurality of UV LED sources 44, which move relative to
the sleeved bottle (39, 40). The relative movement may be achieved
by moving the sleeved bottle (39,40) and/or by moving the UV light
sources 44, for instance in a circular spinning movement.
[0106] As shown in FIG. 6B, when the sleeve 41 is provided in the
shape of a flat film 50, the film may also be wrapped immediately
around the bottle 39 that is rotated in a circumferential direction
56 of the bottle 39. An edge part of the cut flat film 50 is
provided with a strip of adhesive 54 which bonds two overlapping
edge parts of the flat film to provide the tubular sleeve 41 around
the bottle 39.
[0107] UV devices suitable for producing the UV light required for
embodiments of the invention include UV-LED lamps with the item
code FE300 produced by Phoseon Technology. Details of three FE300
UV-LED lamps with peak wavelengths of 365 nm, 385 nm and 395 nm are
outlined in Table 1 below.
[0108] According to the invention, a UV-light source having a peak
wavelength between 200 nm and 399 nm is used, whereby at least
90.degree. % of the UV-light is within a bandwidth of .+-.30 nm of
the peak wavelength. A UV-light emitter having the claimed narrow
wave length distribution may be used, but it is also possible to
use a UV light source having a wider wavelength distribution and
filtering the light to obtain the claimed narrow wave length
distribution.
[0109] Although the power of the UV-light source may be varied
within a large range, a preferred power of the UV-light source
ranges from 0.5-100 W/cm.sup.2, more preferably from 1-30
W/cm.sup.2, and most preferably from 3-20 W/cm.sup.2. Suitable
UV-light emitters are for instance FE300 (365 nm): 3.3 W/cm.sup.2,
and FE300 (385 nm): 5.5 W/cm.sup.2.
[0110] The preferred UV LED devices may use any tip disposition,
and one line type UV LED emitters such as FE300 (Phoseon), and/or
multi line type UV LED emitters such as FJ 100 (Phoseon) may be
used.
[0111] Preferred lenses may have any shape and comprise rod lenses
and flat lenses, whereby a rod lens is more preferred than a flat
lens in order to keep the irradiation power at an even distance
from the light source. The distance between the UV-light source and
the product surface to be irradiated may be varied but is
preferably close enough to prevent a large reduction of the
irradiation power, which typically reduces with distance. A
preferred distance between a product surface to be irradiated and a
UV-light source is <75 mm, more preferably <50 mm, even more
preferably <30 mm, and most preferably <20 mm.
[0112] The product may be irradiated by the UV-light source in a
device that allows irradiation of substantially the complete
product surface once, or a few times. Preferably, a sleeved product
that needs to be irradiated is moved relative to the UV-light
source or sources. Movement may be achieved in any conceivable way,
such as by hoisting or spinning a product and/or UV-light source,
or a line or multi line of UV-light sources or sleeved
products.
[0113] In addition, for comparison, Table 1 also details an
electrodeless lamp produced by Heraeus Noblelight. This lamp does
not produce the UV-light required for the method of activating the
shrink characteristic of a multi-layered film of the present
invention.
[0114] Tables 2 to 5 below detail the distribution of relative
radiance of each of the lamps listed in Table 1.
[0115] As can be seen from Tables 1 to 5, the lamps produced by
Phoseon Technology all produce UV-light that is within +30 nm of
the peak wavelength.
TABLE-US-00001 TABLE 1 UV devices Percentage Percentage Percentage
Peak Irradiated of intensity of intensity of intensity wave wave in
peak in peak in peak Itemcode length length .+-.10 nm .+-.30 nm
.+-.60 nm Type of UV light Lamp Supplier UV light I 365 nm 350
nm-380 nm 94% 100% 100% UV-LED FE300 Phoseon Technology UV light II
385 nm 370 nm-400 nm 93% 100% 100% UV-LED FE300 Phoseon Technology
UV light III 395 nm 380 nm-410 nm 90% 100% 100% UV-LED FE300
Phoseon Technology UV light IV 365 nm 200 nm-500 nm 15% 18% 39%
Electrodeless LIGHT Heraeus Noblelight lamp HAMMER- 10; H+ bulb
TABLE-US-00002 TABLE 2 UV light I 365 nm Distribution Wave length
Range of Relative irradiance <350 nm 0% 350 nm-355 nm 1% 355
nm-360 nm 8% 360 nm-365 nm 30% 365 nm-370 nm 34% 370 nm-375 nm 22%
375 nm-380 nm 5% .gtoreq.380 nm 0% Total 100%
TABLE-US-00003 TABLE 3 UV light II 385 nm Distribution Wave length
Range of Relative irradiance <370 nm 0% 370 nm-375 nm 1% 375
nm-380 nm 7% 380 nm-385 nm 27% 385 nm-390 nm 41% 390 nm-395 nm 19%
395 nm-400 nm 5% .gtoreq.400 nm 0% Total 100%
TABLE-US-00004 TABLE 4 UV light III 395 nm Distribution Wave length
Range of Relative irradiance <390 nm 2% 390 nm-395 nm 15% 395
nm-400 nm 43% 400 nm-405 nm 30% 405 nm-410 nm 8% 410 nm-415 nm 2%
Total 100%
TABLE-US-00005 TABLE 5 UV light IV 365 nm Distribution Wave length
Range of Relative irradiance <300 nm 48% 300 nm-310 nm 4% 310
nm-320 nm 7% 320 nm-330 nm 1% 330 nm-340 nm 2% 340 nm-350 nm 0% 350
nm-360 nm 1% 360 nm-370 nm 13% 370 nm-380 nm 1% 380 nm-390 nm 1%
390 nm-400 nm 1% 400 nm-410 nm 6% 410 nm-420 nm 1% 420 nm-430 nm 1%
.gtoreq.430 nm 13% Total 100%
Base Layer
[0116] The multi-layer films that are configured to be shrunk on
the application of heat comprise a base layer. The base layer film
of the multi-layered film comprises a shrinkable film, and
preferably comprises over 95% of thermoplastic resin. Suitable
types of base layer are detailed in Table 6 below. Their heat
shrinkage in TD is shown in the Table 6.
TABLE-US-00006 TABLE 6 Spec Heat Heat Heat Shrink Shrink Shrink
Formulation ratio ratio ratio Film ST @60.degree. C. @90.degree. C.
@150.degree. C. Thickness Ratio for for for Name (.mu.m) supplier
Surface Core Middle (TD) 10 sec 10 sec 10 sec Haze Film I PETG TD
Pentalabel .RTM. 50 Klockner PETG 4-6R 0 65 77 2.0 shrink film LF-
TG10F12- T45 Film II Hybrid Fancylap 40 GUNZE PETG Adhesive SBS
4-6R 0 70 78 4.0 multilayer TD HG8 layer shrink film Film III
Olefin Fancylap 50 GUNZE COC PP 4-6R 0 55 76 10.0 multilayer TD FL1
shrink film Film IV APET TD -- 40 -- APET* 4R 0 5 31 2.0 shrink
film (@90d) Film V Aclyic coated Label-Lyte 40 Jindal Aclylic PP
BOPP 0 0 7 2.0 BOPP film LL666 coating
[0117] The heat shrink ratio of the APET and BOPP films of Table 6
at 130.degree. C. for 2 min is APET: 34%, and BOPP: 3%.
Photothermic and Design Layers
[0118] Shrinkable films adapted to be shrunk may also comprise ink
in a photothermic layer and/or a design layer. Examples of such
inks are listed in Table 7.
[0119] These inks may be printed onto another layer of the film,
for example the base layer film, using Gravure printing. The layers
of printed ink may be 1.0 .mu.m thick. Titanium dioxide may be used
in the white ink composition, for instance an amount of 50% by
weight of the total white ink composition.
[0120] Alternatively, a photothermic layer may comprise a clear
lacquer (i.e. a "clear lac"). Suitable lacquers include Lacquers B
and C listed in Tables 8-1 and 8-2.
TABLE-US-00007 TABLE 7 Color inks for Photothermic layer or Design
layer Color Code n. Name of color inks medium Solvent Supplier
White WB68-0AFG Pluritech White NITROBASE CLEAR 50/50 EtAc/TSDA
Flint CSWS - 01-21990 SLEEVEFLEX WHITE SOLVAFILM P SL TV nPr-Ac
Sunchemical Cyan WZ61-15AF NITROBASE CYAN NITROBASE CLEAR 2 TO 1
TSDA/ Flint nPrAc YSBL-05- Finetap Cyan SOLVAFILM P SL TV/
nPr-Ac/EtAc Sunchemical 21519/JP01 NC Vanish Magenta WZ61-36BF
NITROBASE MAGENTA NITROBASE CLEAR 2 TO 1 TSDA/ Flint nPrAc YSBL-04-
Finetap Magenta SOLVAFILM P SL TV/ nPr-Ac/EtAc Sunchemical
21521/JP01 NC Vanish Yellow WZ61-55DF NITROBASE YELLOW NITROBASE
CLEAR 2 TO 1 TSDA/ Flint nPrAc YSBL-02- Finelap Yellow SOLVAFILM P
SL TV/ nPr-Ac/EtAc Sunchemical 21517/FJ09 NC Vanish Black WZ61-96BF
NITROBASE BLACK NITROBASE CLEAR 2 TO 1 TSDA/ Flint nPrAc YSBL-09-
Finelap Black SOLVAFILM P SL TV/ nPr-Ac/EtAc Sunchemical 21524/JP01
NC Vanish *inks from Flint is used for example.
TABLE-US-00008 TABLE 8.1 Type Code n. Medium Solvent viscosity
Supplier Lacquer A WB63- ELIOTECH n-propyl 18-20 sec Flint 0VSG SL
CLEAR Acetate
TABLE-US-00009 TABLE 8.2 Formulation (Base lacquer + UV absorber)
Note Base UV Absorber Type lacquer UV absorber Solvent Viscosity
type Chemical name of UV absorber Lacquer B Lacquer A Tinuvin
Supplied by n-propyl 18-20 sec Benzotriazol
2-(2H-benzotriazol-2-yl)-4,6- (100 wt %) 328 BASF Acetate
ditertpentylphenol (3 wt %) Lacquer C Lacquer A Seesorb Supplied by
n-propyl 18-20 sec Benzophenone 2,2',4,4'- (100 wt %) 106 SHIPRO
Acetate Tetrahydroxybenzophenone (13 wt %) KASEI KAISHA LTD
Example 1
[0121] Shrink films (i.e. films that are configured to be shrunk)
were prepared using a base layer selected from Table 6. In
addition, a photothermic layer was applied to this base layer. This
photothermic layer comprised one of the Flint inks listed in Table
7, or a clear lacquer selected from those listed in Table 8-2.
These films form working examples I-1 to I-11 in Table 9 below.
[0122] Comparison examples I-1 to 1-7 listed in Table 9 comprise
only a base layer (i.e. there is no photothermic layer). In
comparison example I-8, the shrink film comprises Lacquer A in the
printed layer. The printed Lacquer A does not comprise a
photothermic material.
[0123] UV light was applied to these shrink films using one of the
UV lamps described in Table 1. The percentage shrinkage of these
films by the UV light was then measured and the results of these
shrinkage experiments are given in Table 9.
TABLE-US-00010 TABLE 9 Flat Shrinkage without design layer
photothermic layer (P) UV Based Film (B) UV abs UV shrinkage by UV
device TYPE UV abs % {circle around (1)} Ink type (B + P = abs %
1.5 J/cm2 4 J/cm2 6 J/cm2 Comparison example I-1 UV light I Film I
8% -- 8% 0% 0% 0% 0% Comparison example I-2 UV light II Film I 8%
-- 8% 0% 0% 0% 0% Comparison example I-3 UV light III Film I 8% --
8% 0% 0% 0% 0% Comparison example I-4 UV light I Film II 9% -- 9%
0% 0% 0% 0% Comparison example I-5 UV light I Film III 7% -- 7% 0%
0% 0% 0% Comparison example I-6 UV light II Film IV 8% -- 8% 0% 0%
0% 0% Comparison example I-7 UV light II Film V 7% -- 7% 0% 0% 0%
0% Comparison example I-8 UV light I Film I 8% Lacquer A 8% 0% 0%
0% 0% Working example I-1 UV light I Film I 8% Magenta 40% 32% 0%
0% 49% Working example I-2 UV light I Film I 8% Cyan 88% 80% 0% 48%
77% Working example I-3 UV light I Film I 8% Yellow 40% 32% 0% 0%
71% Working example I-4 UV light I Film I 8% Black 97% 89% 8% 63%
77% Working example I-5 UV light I Film I 8% White 94% 86% 6% 43%
77% Working example I-7 UV light I Film II 9% White 93% 84% 0% 58%
74% Working example I-8 UV light I Film III 7% White 94% 87% 4% 34%
70% Working example I-9 UV light II Film IV 8% White 94% 86% 50%
Working example I-10 UV light II Film V 7% White 94% 87% 17%
Working example I-6 UV light I Film I 8% Lacquer B 87% 79% 0% 33%
74% Working example I-11 UV light I Film I 8% Lacquer C 89% 81% 5%
45% 77%
[0124] In the multi-layer films of Table 9, there is no design
layer.
Example 2
[0125] In Example 2, multi-layer films were prepared from a base
layer, a photothermic layer and a design layer. Details of these
multi-layer shrink films are listed in Table 10.
[0126] The base layer was selected from those examples listed in
Table 6, the photothermic layer comprises the white Flint ink
listed in Table 7, and the design layer comprises additional flint
inks of Table 7.
[0127] UV light was applied to the films using one of the UV lamps
listed in Table 1. The shrinkage of the multi-layer films of
Example 2 was measured and the results are listed in Table 10.
[0128] The working examples II-2, 4, 5 and the comparative example
II-1 have a continuous backing white on design layer that is
printed with a number of color inks (cyan, magenta, black, yellow)
to eliminate overlap with each design ink below a base layer.
[0129] In working example II-3 a continuous transparent lacquer
comprising photothermic material shown as lacquer B in table 8 is
printed on top of a base layer film together with a number of color
inks (cyan, magenta, black, and yellow) to eliminate overlap with
each design ink on the other side of the base layer film, meaning
below the base layer film.
[0130] When any color is described as a design layer in the table,
it means that the part does not have a design layer.
TABLE-US-00011 TABLE 10 Flat Shrinkage with design layer
photothermic layer Design layer UV UV Total layer Free Shrinkage
dispersion of shrinkage Free shrinkage Film abs UV abs % abs % UV
abs % UV abs % (A) by light (2.sigma.) (B) by light UV device TYPE
UV abs % {circle around (1)} Color (B + P = (P = 2 - Color (B + D =
(D = 3 - (B + P Min abs % 0.4 J/cm2 0.4 J/cm2 Classification
Comparison UV light IV Film 8% Whit 94% 86% -- -- -- 94% 94% 37%
23% B example II-1 Whit 94% 86% Magent 40% 32% 97% 54% Whit 94% 86%
Cyan 88% 80% 97% 59% Whit 94% 86% Black 97% 89% 97% 64%
photothermic layer Design layer Total layer Free dispersion of Free
Film UV UV abs UV UV UV Shrinkage shrinkage shrinkage UV UV abs %
abs % (P = abs % abs % abs % Min (A) by light (2.sigma.) (B) by
light device TYPE {circle around (1)} Color (B + P = {circle around
(2)} - Color (B + D = (D = {circle around (3)} - (B + P abs % 1.5
J/ 4 J/cm2 6 J/cm2 1.5 J/ 4 J/cm2 6 J/cm2 Classification Working
example UV Film I 8% Whit 94% 86% -- -- -- 94% 94% 6% 43% 77 7% 8%
3% A II-2 light I Whit 94% 86% Magent 40% 32% 97% 6% 43% 75 Whit
94% 86% Cyan 88% 80% 97% 0% 44% 75 Whit 94% 86% Yellow 40% 32% 97%
0% 49% 76 Whit 94% 86% Black 97% 89% 97% 0% 38% 73 Working example
UV Film I 8% Lacqu 87% 79% -- -- -- 87% 87% 6% 37% 76 5% 10% 0% A
II-3 light I Lacqu 87% 79% Magent 40% 32% 90% 0% 27% 76 Lacqu 87%
79% Cyan 88% 80% 90% 0% 36% 76 Lacqu 87% 79% Yellow 40% 32% 90% 0%
40% 76 Lacqu 87% 79% Black 97% 89% 90% 0% 36% 76 photothermic Free
dispersion of Film layer Design layer Total layer Shrinkage
shrinkage UV UV UV abs UV UV UV (A) by light (2.sigma.) abs abs %
(P = abs % abs % abs % Min 1.5 J/ 1.5 J/ Appearance after UV device
TYPE % 1 Color (B + P = {circle around (2)} - Color (B + D = (D =
{circle around (3)} - (B + P abs % 4 J/cm2 6 J/cm2 4 J/cm2 6 J/cm2
Classification Working example UV light II Film I 8% Whit 86% 78%
-- -- -- 86% 86% 48 69% 76 7% 5% 2% A II-4 Whit 86% 78% Magent 31%
23% 93% 50 63% 78 Whit 86% 78% Cyan 65% 57% 97% 56 68% 78 Whit 86%
78% Yellow 52% 44% 97% 50 65% 77 Whit 86% 78% Black 98% 90% 97% 56
68% 77 Working example UV light III Film I 8% Whit 69% 61% -- -- --
69% 69% 36 63% 76 13% 12% 2% A II-5 Whit 69% 61% Magent 33% 25% 87%
43 71% 77 Whit 69% 61% Cyan 45% 37% 87% 42 68% 78 Whit 69% 61%
Yellow 60% 52% 97% 47 77% 78 Whit 69% 61% Black 94% 86% 97% 53 77%
78 indicates data missing or illegible when filed
Example 3
[0131] As with Example 2, the films of Example 3 comprise a base
layer, a photothermic layer and a design layer. The multi-layer
shrink films of Example 3 are listed in Table 11.
[0132] The results of experiments conducted on the films of Example
3 are given in Table 11. The top part of Table 11 discloses
experiments on the indicated films, whereas the bottom part of
Table 11 describes the results of the carousel and around shrink
test performed on working examples II-4. III-1 and III-2.
TABLE-US-00012 TABLE 11 Shrink test for products Design layer Film
photothermic layer UV UV Total layer UV abs UV abs UV abs % abs %
abs % UV abs % UV device TYPE % {circle around (1)} Color (B + P =
{circle around (2)}) (P = {circle around (2)} - {circle around
(1)}) Color (B + D = {circle around (3)} (D = {circle around (3)} -
{circle around (1)}) (B + P + D) Min abs % Working UV light II
FilmII 9% White 86% 77% -- -- -- 86% 86% example White 86% 77%
Magenta 32% 23% 93% III-1 White 86% 77% Cyan 65% 56% 97% White 86%
77% Yellow 53% 44% 97% White 86% 77% Black 98% 89% 97% Working UV
light II FilmIII 7% White 86% 79% -- -- -- 86% 86% example White
86% 79% Magenta 31% 24% 93% III-2 White 86% 79% Cyan 64% 57% 97%
White 86% 79% Yellow 52% 45% 97% White 86% 79% Black 98% 91% 97%
Carousel Around UV Film Min shrink shrink device TYPE Abs %
Classification Classification Working UV light Film I 86% A A
example II-4 II Working UV light Film II 86% A A example III-1 II
Working UV light Film III 86% A A example III-2 II
Experiment to Analyse the Percentage of UV Absorption
[0133] In Examples 1, 2 and 3, the UV absorption was measured using
a UV spectrometer of the type Shimadzu UV-VIS Recording
spectrophotometer UV-2401PC. The UV absorption was calculated from
transmittance and reflectance as measured using the standard
ISO13468-2 (=JIS K 7361-2).
[0134] In Examples 1 to 3, the UV absorption of the multi-layer
film and a part of multi-layer film or same formulations as the
part of the multi-layer film was measured. Firstly, the
transmittance and reflectance of the film were measured. Secondly,
the UV absorption percentage was calculated using:
UV absorption %=100-(transmittance+reflectance)
[0135] In addition, the UV absorption of the photothermic layer was
measured. This was achieved by: [0136] (1) Measuring the UV
absorption of only the base layer film [0137] (2) Measuring the UB
absorption of the photothermic layer and the base layer film [0138]
(3) Calculating the UV absorption of the photothermic layer as
follows:
[0138] UV absorption of the photothermic layers=(2)-(1)
[0139] A similar method was used to calculate the UV absorption of
the design layer (if present).
Free Shrink Test
[0140] In the tables, the free shrinkage by light has also been
measured.
[0141] In the method used to measure the free shrinkage, samples of
the multi-layered films were first prepared. These samples each had
dimensions of: [0142] 50 mm in the transverse direction (TD) [0143]
15 mm in the machine direction (MD)
[0144] Then: [0145] (1) Each sample was placed on a PET sheet that
has not been treated with any coating. [0146] (2) Each sheet was
then placed on a conveyer belt and passed under the UV light source
in a constant condition. [0147] (3) The free shrinkage was then
calculated using:
[0147] Shrinkage (%)=(L.sub.0-L.sub.1)/L.sub.0.times.100; with
[0148] L.sub.0: Length of transverse direction before irradiation
[0149] L.sub.1: Length of transverse direction after irradiation In
addition, the appearance of the shrunken sample was checked and
classified either A or B: [0150] A--if there was an even shrink,
[0151] B--if there was an uneven shrink
[0152] In Examples 1 to 3, three samples of each example listed in
the tables were used and the average value (i.e. the mean value)
obtained from these three samples is given in the tables.
Carousel Shrink Test
[0153] In Example 3, a carousel shrink test was also performed.
This test involved: [0154] (1) Preparing a lay-flat sample (a
seamed tubular sleeve laid flat) that has a width of 72 mm and a
cut height (or pitch) of 95 mm in size [0155] (2) The sample was
then formed into a sleeve and arranged around a bottle so that a
maximum shrinkage of 30% is required to fit the sleeve to the
bottle [0156] (3) The bottle and sample were then placed in the
middle of a set of six UV lights of type UV light II with a rod
lens and spun around at 200 bpm [0157] (4) The sample was then
irradiated with 7 J/cm of UV light II [0158] (5) After shrinking,
the appearance was checked an classified as either A or B, where:
[0159] A--indicates shrinking without concentration by colour
influence [0160] B--indicates shrinking with concentration by
colour influence
Around Light Shrink Test
[0161] In Example 3, an around light shrink test was additionally
performed. This test involved: [0162] (1) Preparing a lay-flat
sample that is 72 mm by 95 mm in size [0163] (2) The sample was
then formed into a sleeve and arranged around a bottle so that a
maximum shrinkage of 30% is required to fit the sleeve to the
bottle. [0164] (3) The bottle and sample were then placed in the
middle of a set of four UV lights of type UV light II with a ROD
lens. These four UV lights are arranged in a square configuration
around the bottle. [0165] (4) The bottle was then moved vertically
at a speed of 1 m/min through the middle of the square of UV lights
so that the sample is irradiated at 24 J/cm.sup.2. [0166] (5) After
shrinking, the appearance was checked and classified as for the
carousel test.
* * * * *