U.S. patent application number 11/169576 was filed with the patent office on 2006-01-05 for process for manufacturing a packaging material.
This patent application is currently assigned to ALCAN TECHNOLOGY & MANAGEMENT LTD.. Invention is credited to Franz Peler Hombach, Berl Molter, Hans Rudolf Nageli, Steve Santa.
Application Number | 20060003122 11/169576 |
Document ID | / |
Family ID | 34932174 |
Filed Date | 2006-01-05 |
United States Patent
Application |
20060003122 |
Kind Code |
A1 |
Nageli; Hans Rudolf ; et
al. |
January 5, 2006 |
Process for manufacturing a packaging material
Abstract
A process for manufacturing a packaging material having at least
two films (12, 16) or foils (14) bonded together via at least one
layer of adhesive (13,15) to give a multi-layer laminate (10), is
such that the adhesive layers (13,15) are of an adhesive that cures
under electron beam radiation, and the laminate (10) is radiated
with electrons for the purpose of curing the adhesive. The laminate
is particularly suitable for the manufacture of self-standing
pouches, in particular for drinks. The production of the laminate
using adhesives that cure under electron beam radiation leads to a
significantly reduced throughput time and to a reduction in the
emission of solvents when replacing solvent-based adhesives by
electron beam curing adhesives.
Inventors: |
Nageli; Hans Rudolf;
(Neuhausen, CH) ; Hombach; Franz Peler; (Beringen,
CH) ; Molter; Berl; (Crestwood, KY) ; Santa;
Steve; (Lake Bluff, IL) |
Correspondence
Address: |
FISHER, CHRISTEN & SABOL
1725 K STREET, N.W.
SUITE 1108
WASHINGTON
DC
20006
US
|
Assignee: |
ALCAN TECHNOLOGY & MANAGEMENT
LTD.
|
Family ID: |
34932174 |
Appl. No.: |
11/169576 |
Filed: |
June 30, 2005 |
Current U.S.
Class: |
428/35.7 |
Current CPC
Class: |
B32B 2553/00 20130101;
B32B 37/02 20130101; B32B 37/12 20130101; B32B 2323/00 20130101;
B32B 27/16 20130101; Y10T 428/1352 20150115; B32B 2311/24 20130101;
B32B 2310/0887 20130101; B32B 7/12 20130101; B32B 2367/00 20130101;
B65D 31/06 20130101; B32B 37/203 20130101 |
Class at
Publication: |
428/035.7 |
International
Class: |
B65D 1/00 20060101
B65D001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 1, 2004 |
EP |
04405406.2 |
Claims
1. A process for manufacturing a packaging material having at least
two films (12, 16) or foils (14) bonded together via at least one
layer of adhesive to give a multi-layer laminate (10), whereby the
adhesive layer/layers (13,15) is/are cured, at least one adhesive
layer (13) is of an electron beam curable adhesive and the laminate
(10) is radiated with electrons for the purpose of curing the
adhesive.
2. The process according to claim 1, wherein the laminate (10)
exhibits three films (12,16) or foils (14) and two adhesive layers
(13,15).
3. The process according to claim 2, wherein one of the adhesive
layers (13) is an adhesive that cures under electron beam
radiation.
4. The process according to claim 2, wherein both adhesive layers
(13,15) are an adhesive that cures under electron beam
radiation.
5. The process according to claim 3, wherein the first adhesive
layer (13) is an adhesive that cures under electron beam radiation
and the second adhesive layer (15) is a solvent-based or
solvent-free PUR adhesive.
6. The process according to claim 4, wherein the laminate (10)
exhibits the following structure: PET film (12)/first adhesive
layer of an electron beam curing adhesive (13)/aluminum foil
(14)/second adhesive layer of an electron beam curing adhesive
(15)/polyolefin film (16).
7. The process according to claim 5, wherein the laminate (10)
exhibits the following structure: PET film (12)/first adhesive
layer of an electron beam curing adhesive (13)/aluminum foil
(14)/second adhesive film (15) of a solvent-based or solvent-free
PUR adhesive/polyolefin film (16).
8. The process according to claim 5, wherein the laminate exhibits
the following structure: PET film (12)/first adhesive layer of a
solvent-based or solvent-free PUR adhesive (13)/aluminum foil
(14)/second adhesive layer of an electron beam curing adhesive
(15)/polyolefin film (16).
9. The process according to claim 8, wherein the PET film (12)
exhibits printing on the side coated with adhesive.
10. The process according to claim 9, wherein the polyolefin film
is a PE or PP film.
11. The process according to claim 10, wherein the electron beam
curing adhesive is an acrylate-based adhesive.
12. A self-standing pouch manufactured from a laminate (10)
utilizing the process according to claim 10.
13. A self-standing pouch manufactured from a laminate (10)
utilizing the process according to claim 10, wherein at least film
(12) of the laminate (10) forming the outside of the pouch is
laminated via an adhesive layer (13) that cures under electron beam
radiation.
14. The self-standing pouch according to claim 13, wherein the
adhesive that cures under electron beam radiation is an
acrylate-based adhesive.
15. The process according to claim 6, wherein the PET film (12)
exhibits printing on the side coated with adhesive.
16. The process according to claim 6, wherein the polyolefin film
is a PE or PP film.
17. The process according to claim 1, wherein the electron beam
curing adhesive is an acrylate-based adhesive.
18. The self-standing pouch manufactured from a laminate (10)
utilizing the process according to claim 1.
19. The self-standing pouch manufactured from a laminate (10) using
the process according to claim 2, wherein at least film (12) of the
laminate (10) forming the outside of the pouch is laminated via an
adhesive layer (13) that cures under electron beam radiation.
20. The self-standing pouch according to claim 19, wherein the
adhesive that cures under electron beam radiation is an
acrylate-based adhesive.
21. The self-standing pouch according to claim 12, wherein the
adhesive that cures under electron beam radiation is an
acrylate-based adhesive.
22. The self-standing pouch according to claim 18, wherein the
adhesive that cures under electron beam radiation is an
acrylate-based adhesive.
Description
[0001] The invention relates to a process for manufacturing a
packaging material having at least two films or foils bonded
together into a multilayer laminate by means of at least one layer
of adhesive, whereby the adhesive layer/layers is/are
cure-hardened. Also within the scope of the invention is a
self-standing pouch made from the laminate.
[0002] Laminates for manufacturing self-standing pouches for drinks
are manufactured today in two steps using solvent-free adhesives
and in one step using solvent-based adhesives.
[0003] The solvent-free process is environmentally friendly,
however, requires two production steps. In a first step an
aluminium foil is bonded to a printed polyethyleneterephthalate
(PET) film which is coated with a solvent-free poly-urethane (PUR)
adhesive. After a curing time of several hours this pre-laminate
can be bonded to a polyolefin-film using a solvent-based or
solvent-free PUR adhesive. The final structure is:
RET-film/adhesive layer/aluminium foil/adhesive layer/polyolefin
film. After the final curing over a period of several days, the
final laminate can be cut to size and dispatched to the customer.
The throughput time from receipt of order to dispatch of the
finished product depends essentially on the time required for
curing the PUR-adhesive
[0004] The object of the invention is to provide a process of the
kind described at the start by means of which the time required for
curing the adhesive needed for the laminate--and with that the
throughput time can be reduced in comparison with the adhesive
curing time in conventional laminate manufacture.
[0005] That objective is achieved by way of the invention in treat
at least one adhesive layer is of an adhesive that can be cured
using an electron beam and the laminate is radiated with electrons
for the purpose of curing the adhesive.
[0006] The application of an electron beam curable adhesive results
in an increase of the initial adhesion, the so called greentack,
which could not be expected at once. Furthermore the application of
an electron beam curable adhesive results not only in an excellent
adhesion against plastic films but also against aluminium foils. In
addition, an aluminium foil forms a functional barrier for electron
beam curable adhesives, which is important with packaging for food,
in particular beverages.
[0007] The radiation curing of plastics that can be cured with an
electron beam takes place in a fraction of a second on passing
through a radiation station, whereby the final bond strength has
already been essentially achieved without an additional curing time
when the laminate emerges from the radiation station and is
coiled.
[0008] The advantage of manufacturing laminate using adhesives that
can be cured by means of electron beam radiation is not only the
much reduced throughput time, but also in the reduction of solvent
emissions is solvent based adhesives can be replaced by adhesives
that can be cured using an electron beam.
[0009] A preferred laminate exhibits three films or foils and two
adhesive layers, whereby one of the adhesive layers or both
adhesive layers is/are of the electron beam curing type of
adhesive.
[0010] If only one of the adhesive layers is curable with an
electron beam, a solvent based or solvent-free PUR-adhesive is used
by way of preference for the second adhesive layer.
[0011] A preferred laminate exhibits the following structure: PET
film/first adhesive layer of electron beam curable
adhesive/aluminium foil/second adhesive layer of an electron beam
curable adhesive/polyolefin film.
[0012] If only one of the two adhesive layers is of an electron
beam curable adhesive, a further preferred laminate exhibits the
following structure: PET film/first adhesive layer of electron beam
curable adhesive/aluminium foil/second adhesive layer of a solvent
based or solvent-free PUR adhesive/polyolefin film or PET
film/first adhesive layer of a solvent based or solvent-free PUR
adhesive/aluminium foil/second adhesive layer of an electron beam
curable adhesive/polyolefin film
[0013] Preferred polyolefin films are sealable films of
polyethylene (PE) or polypropylene (PP). For applications involving
sterilisation or high temperature cooking, PP is preferable because
of its ability to withstand high thermal loads.
[0014] The PET film may exhibit printing on it. The printing is
preferably provided as counterprint on the side coated with
adhesive.
[0015] The electron beam curable adhesive is preferably an adhesive
on an acrylate basis.
[0016] The adhesive on an acrylate basis may contain monomers,
oligomers or mixtures of monomers and oligimers as the basis.
Examples of monomers are mono, di- and multifunctional acrylates
such as phosphoric acid ester acrylates, hydroxy-acrylates,
carboxy-acrylates, amino-acrylates, acrylic acid and acrylamide.
Examples of oligomers are epoxy-acrylates, urethane-acrylates,
polyester-acrylates and silicon-acrylates. The monomers and
oligomers mentioned are either available commercially or can be
manufactured by routine methods. The term "acrylate" (or "acryl")
used here also includes "methacrylate" (or "methacryl", whereby the
acrylates are preferred.
[0017] The laminate manufactured according to the invention is
particularly suitable for manufacturing self-standing pouches, in
particular such for drinks. Preferred is at least for the film of
the laminate forming the outside of the pouch to be laminated using
an adhesive layer that can be cured using an electron beam.
[0018] Further advantages, features and details of the invention
are revealed in the following description of preferred exemplified
embodiments and with the aid of the drawing which shows
schematically in
[0019] FIG. 1 cross-section through a laminated packaging film;
[0020] FIG. 2 manufacture of a pre-laminated partial film of the
packaging film shown in FIG. 1;
[0021] FIG. 3 manufacture of the packaging film in FIG. 1 from the
pre-laminated partial film in FIG. 2;
[0022] FIG. 4 manufacture of the packaging film in FIG. 1 by triple
lamination.
[0023] FIG. 1 shows a packaging film 10 for manufacturing
self-standing pouches for drinks featuring a printed PET film 12
representing the outer side, an aluminium foil 14 as barrier layer
and a sealable PE or PP film 16 representing the inner side. The
PET film 12 is permanently bonded to the aluminium foil 14 by way
of a first adhesive layer 13 and the aluminium foil 14 to the
sealing film 16 by way of a second adhesive layer 15. In a typical
packaging film 10 the thickness of the PET film is e.g. 12 .mu.m,
the thickness of the aluminium foil 8-10 .mu.m and the thickness of
the sealing layer 90-100 .mu.m.
[0024] FIG. 2 shows the manufacture of a partial film A comprising
PET film 12, adhesive layer 13 and aluminium foil 14. The printed
PET film 12 is uncoiled from a first spool 18 in strip form an
continuously coated with adhesive 13. The aluminium foil 14 is
uncoiled in strip form from a second spool 20 and fed to the PET
film 12 coated with adhesive 13 and laminated to this to a partial
film A. The partial film A is passed through a radiation station 22
in which the adhesive layer 13 is cured by electron beam radiation
within a fraction of a second. After leaving the radiation station
22, the partial film A is coiled onto a third spool 24.
[0025] In a further production step, shown in FIG. 3, the sealing
film 16 is uncoiled from a fourth spool 26 and continuously coated
with adhesive 15. The partial film A is fed from the third spool in
strip form and fed to the sealing film 16 coated with adhesive 15
and laminated continuously to this to yield the packaging film 10.
The packaging film passes through a radiation station 28 in which
the adhesive layer 15 is cured by electron beam radiation within a
fraction of a second. On leaving the radiation station 22 the
packaging film 10 is coiled onto a fifth spool 30.
[0026] The second adhesive layer 15 does not necessarily have to be
an electron beam curing adhesive. Instead, it may e.g. be a
conventional PUR adhesive. In that case the curing station 28 is
omitted. The longer curing time required for the PUR adhesive has
no influence on the process for producing the composite film 10 and
simply requires a minimum storage time until it is processed
further.
[0027] Another version of the manufacturing process--not shown in
the drawing--is such that first a partial film B comprising sealing
film 16, adhesive layer 15 and aluminium foil 14 is produced. The
sealing film 16 is uncoiled from a first spool and Continuously
coated with adhesive 15. The aluminium foil is fed to the sealing
film 16 which is coated with adhesive 15 and laminated to this to
give a partial film B. The partial film B passes through a
radiation station in which the adhesive a layer 15 is cured within
a fraction of a second. After leaving the radiation station, the
partial film is coiled onto a third spool.
[0028] In a further step the printed PET film 12 is uncoiled from a
fourth spool and coated continuously with adhesive 13. The partial
film B is fed from the third spool to the PET film 12 coated with
adhesive 13 and laminated in a continuous manner to yield the
packaging film 10. The packaging film 10 passes through a radiation
station in which the adhesive layer 12 is cured by electron beam
curing within a fraction of a second. On leaving the radiation
station the packaging film 10 is coiled onto a fifth spool.
[0029] The first adhesive layer 13 does not necessarily have to be
an electron beam curing adhesive. Instead, it may e.g. be a
conventional PUR adhesive. In that case of course the radiation
station is omitted. The longer curing time required by the PUR
adhesive has no influence on the process for manufacturing the
composite film 10 and requires simply a minimum storage time to be
observed until further processing.
[0030] In a first way of manufacturing the threefold lamination
shown in FIG. 4, the production of the packaging film 10 takes
place by bringing together the PET film 12, the aluminium foil 14
and the sealing film 16 and adhesively bonding via the two adhesive
layers 13, 15 in one single pass. The printed PET film 12 is
uncoiled from a first spool 32 and coated continuously with
adhesive 13. The aluminium foil 14 is fed in strip form from a
second spool 34 to the PET film 12 coated with adhesive 13 and
laminated continuously to this to yield partial film A. The sealing
film 16 is uncoiled from a third spool 36 and coated continuously
with adhesive 15, fed in strip form to the partial film A and
laminated to it in a continuous manner yielding the packaging film
10. The sealing film 16 is uncoiled from a third spool 36 and
coated with (adhesive 15, fed in strip form to the partial film A
and laminated to it in a continuous manner yielding the packaging
film 10. The packaging film 10 passes through a radiation station
38 with adequate capacity enabling both adhesive layers 13, 15 to
be cured by electron beam radiation within a fraction of a second
in one single pass. On leaving the radiation station 38 the
packaging film 10 is coiled onto a fourth spool 40.
[0031] In a second way of manufacturing the threefold lamination
shown in FIG. 5, the production of the packaging film 10 takes
place the same way as the production shown in FIG. 4 by bringing
together the PET film 12, the aluminium foil 14 and the sealing
film 16 and adhesively bonding via the two adhesive layers 13,15 in
one single pass. The aluminium foil 14 is uncoiled from a first
spool 42 and coated continuously with adhesive 15 at a first
adhesive application station 17. The sealing film 16 is fed in
strip form from a second spool 44 to the aluminium foil 14 coated
with adhesive 15 and laminated continuously to this to yield
partial film B. The partial film B passes through a first radiation
station 50 with adequate capacity enabling the adhesive layer 15 to
be cured by electron beam radiation within a fraction of a second.
The PET film 12 is uncoiled from a third spool 46 and coated
continuously with adhesive 13 at a second adhesive application
station 19, fed in strip form to the partial film B on leaving the
first radiation station 50 and laminated to it in a continuous
manner yielding the packaging film 10. The packaging film 10 passes
through a second radiation station 52 with adequate capacity
enabling also the adhesive layer 13 to be cured by electron beam
radiation within a fraction of a second. On leaving the radiation
station 52 the packaging film 10 is coiled onto a fourth spool
48.
[0032] Immediately after coiling onto the spool 40, 48 the
packaging film 10 with fully cured adhesive layers 13, 15 is
divided on a slitting line into commercially required breadths
ready for dispatch.
[0033] It is self-evident that, on bonding the films or foils in
the above laminating processes, the adhesive may also be deposited
on the other films or foils mentioned in the examples.
* * * * *