This invention relates to Fibre Glass Reinforced Aluminiua
Foil and a method for manufacturing the same
Aluminium Foils have wide ranges of Applications, These
Foils are very thin. Pure Aluminium Foil, in other words,
has Halted Mechanical strength. In the process, where strength
is main criteria, thin foil alone cannot be used. Accordingly,
the Aluminium Foil is laminated on a paper backing sheet
with or without an additional intermediate thin plastic film,

such as polyethylene. Such laminated Foils have wide applications
viz. cartons made of Paper-Polyethylene-Aluminium Foil are
widely used for dispensing Food Products such as soft drinks
and many other consumer items.
Aluminium Foils are used for domestic purposes, such as,
for decorative purposes, Food packaging otc. In the Consumer
Industries, laminated Aluminium Foil Cartons are also used
as explained before. A paper-polyethylene laminated Aluminium
Foil is met suitable for several other Industrial Applications
where stringent properties, such as* satisfactory tensile
strength, yield strength, insulation properties, lightweight,
moisture proof are required. These cannot be realised with
paper-polyethylene laminated Aluminium Foils.
Eventually, it is therefore an objective of this invention
to propose Improved Aluminium Foil that will have satisfactory
sechamical properties such as, improved tensile strength, and
yield strength than the known paper-polyethylene laminated
Aluminium Foil.
Furthermore, another objective of this invention is to
propose improved laminated Aluminium Foil that exures better
themal insulation properties than hitherto know before.
Accordingly, this improved laminated Aluminium will can
conveniently be glued or otherwise fixed to several surfaces,
such as metal surfaces, glass surfaces, for improving its
utility.
Thus, according to this invention there is improved
laminited Aluminium Foil comprising Four components namely,
(i) Metallic Aluminium Foil, (ii) Kraft Paper, {&%) Fibre
Glass and (iy) Polder layer such as polyethyles* and wherein
the Aluminium Foil is bonded to one surface of «m? Kraft Paper
while toe fibre glass and polymer layer are bondee to other
surface of the Kraft Paper.
The glass fibre yarn is preferably used in ttee form of a
netted mat* The mat is preferably made of a plurality of glass
fibres Held longitudinally and a plurality of glass fibre
held transversely*
A glass fibre is obtained by spining from a fiat yarn.
The Kraft Paper is preferably unbleached and this has
low water absorption index.
A polyethylene Film is of commercial grade of low density
variety obtained by instant melt spining.
According to this invention, Aluminium Foil is laminated
with one side of a Kraft Paper using an organic adhesive
material to obtain a first Kraft Paper-laminated Aluminium
Foil. This is followed by laminating other side of Kraft
Paper with a layer of fibre glass using simultaneously a layer

of organic polymer such as polyethylene film on the second
side of the Kraft Paper.
The Aluminium Foil is laminated to the Kraft Paper
using an adhesive material preferably selected fro* vinyl
alcohol, vinyl acetate, casein-gus based adhesive ormetalic
silicate, The adhesive material is used in the fora of a
water solution or water solvent aixture solution.
The Fibre glass material is used in the form of a net
and this is bonded to the under surface of the Kraft Paper
using hot extruded polyethylene File at site.
Thus final laminated material obtained consists of
four layers material sandwiched together where the surface
of the Aluminium Foil remains on top.
The invention will now be more fully described in the
following example.

Fox manufacturing Fibre Glass reinforced
Aluminium Foil, the Foil can very in thickness
froa 5.5. microns to 15 aicrons. We used a
10 aicron foil.
ii) Kraft Paper :
Unbleached Kraft Paper of preferably 50 GSM
and having a water absorption index of preferably
35, was used. Tensile strength was
measured as per ASTM D-202. Values in the

longitudinal (machine) and transverse (cross)
was maintained preferably 90 MPa and at
preferably 55 MPa respectively. Similar values
of yield strength in the longitudinal and
transverse directions were preferably 60 MPa
and 35 MPa.
ill) Polyethylene :
Commercial grade low density Polyethylene
can be used for the same.
The material may be spun from 75 to 150 flat
yarn in a manner suitable for machine unwinding.
Step - 1. About 10 micron ALuminium Foil was first
laminated to the specified paper with vinyl
alcohol* The medium1 can be water or water*
solvent mixtures* It can be heat laminated.
One or two component adhesive utilising the
dry lamination process can also be used*
Step - 2. The above paper foil laminate was then laminated
to Fibre glass net using polyethylene ¥ilm of
60 gauge (The gauge can be 40-150)•
The polyethylene film was extruded in an
extruder*
The material thus obtained above was subjected to
estimation of its properties*
A laminate measuring 100 metres in length and 600 metre
in width had the following properties. One can manufacture
laminate of higher lengths*
lie have studied the properties of ordinary paper
polyethylene laminated Aluminium Foil and compared the same
laminated Aluminium FoiJU The results are tabulated in the
laminated Aluminium Foil The results are tabulated in the
accompanying table from which a superior quality of laminated
Aluminium foil of this invention can be understood•
The improved laminated Aluminium Foil of this
invention has wide range of Applications in the domestic
consumer Industry and other Industrial Applications. Some of
the areas where the improved Aluminium Foil of this invention
can be used are the following t
i) Air Conditioning Insulation.
11) Domestic purposes for Room Insulation.
iii) Automobile Industry.
iv) Insulation in Analytical Laboratories.
v) Philips Lamps,
vi) Flower Package.
vii) Book Binding.
viii) Electrical Industry.
ix) Transportation industry for containers transporting
frozen meats/vegetables/deserts etc.
In addition to the above it is possible to make
suitable modification In the selection of Raw materials and
process condition to obtain various customer oriented products.
WE CLAIM :-
1) Improved Laminated Aluminium Foil comprising four
components namely, (i) Metallic Alluminium Foil, (11) Kraft
Paper, (iii) Fibre glass and (iv) polymer layer such as
Polyethylene and wherein the Aluminium foil as bonded to one
surface of the Kraft Paper and the fibre ginan and polymer
layer are bonded to other surface at the kraft Paper.
2) Improved Laminated Aluminium foil as claimed in Claim-1
wherein the Glass Fibre yarns is preferably used in the Form
of a netted mat.
3) Improved Laminated Aluminium Foil as claimed in Claim-2
wherein the mat is preferably made of a plurality of Glass
Fibres, held longitudinally and a plurality of Glass Fibre
held transversely.
4) Improved Laminated Aluminium Foil as claimed in Claims
1 to 3 wherein Glass Fibre is obtained by spining from a flat
yarn.
5) Improved Laminated Aluminium Foil as claimed in
Claim-1 or Glaim-4 wherein the Kraft Paper is preferably unbleached
and has low water absorption index.
6) A method for preparing improved Laminated Aluminium
Foil as claimed in Claim-1 to Claim-5 comprising subjecting
Aluminium Foil to lamination with one side of a Kraft Paper
using an organic Adhesive material to obtain a first Kraft
Paper laminated Aluminium Foil, followed by laminating the
other side of Kraft Paper with a layer of Fibre glass using
simultaneously a layer of organic polymer such as polyethylene
Film on the second side of the Kraft Paper.
7) A method as claimed in Claim-6 wherein the polyethylene
Film is of commercial grade low density variety obtained by
instant melt spining.
8) A method as claimed in Claims 6 & 7 wherein the
Aluminium Foil is laminated to the Kraft Paper using an adhesive
material preferably selected from vinyl alcohol, vinyl acetate
or caseingum based adhesive.
9) A method as claimed in Claim-8 wherein the adhesive
material is used in the form of a water solution or water
solvent mixture solution.
10) A method as claimed in Claims 6 to 9 wherein the Fibre
Glass material is used in the form of a net and is bonded to
the under surface of the Kraft Paper using hot extruded
polyethylene Film at site.
11) A method as claimed in Claims 6 to 10 wherein the final
material obtained is a four layer material sandwiched together
with the surface of the Aluminium Foil remaining on top.
12) Improved Laminated Aluminium Foil as herein described.
13). A method for the manufacture of Improved Laminated
Aluminium Foil as herein described.

An aluminium-based laminate includes (a) a substrate layer, (b) a primer layer, (c) a bonding layer of
polyethylene attached to the substrate layer with the assistance of the primer layer, (d) an aluminum foil
layer secured to the bonding layer, (e) a substantially solvent-free adhesive layer of ionomer or ethylene-
vinylacetate copolymer applied to the aluminium foil layer. and (f) a sealing layer of ethylene and/or
propylene polymer maintained on the aluminium foil layer by means of the substantially solvent-free
adhesive layer. The ionomer is a copolymer of an alpha -mono-olefin, an unsaturated organic acid, and a
metal salt of the unsaturated organic acid. A packaging bag made of such a laminate is able to withstand
pasteurisation without any tendency to delaminate.