Note: Descriptions are shown in the official language in which they were submitted.
1~3~
-- 1 --
LAMINATED, THERMAL INSULATION PANEL
BACKGROUND OF THE INVENTION
1. Field of the invention:
The present invention relates to a laminated,
thermal insulation panel for outside covering of a cons-
truction, such as a residential house, which insulation
panel is impervious to air and moisture from the outside
but is permeable to water vapor from the inside.
2. Brief description of the prior art:
Rigid polystyrene insulation material is pre-
sently widely used in residential construction for exterior
wall insulation. Such insulation material is commonly
available under the Eorm expanded,molded polystyrene boards.
These boards are mounted adjacent -to each other to cover
the entire, exterior wall surface of the residential cons-
truction.
~3~ 7
-- 2
In order to prevent air and moisture Erom the
outside to penetrate into the walls, a membrane permeahle
to water vapor but impervious to air and moisture is applied
externally on the polystyrene boards. This membrane must
totally and adequately cover the exterior surface to give
proper protection. In particular, it must seal a]l cracks,
fissures and joints in the wall s-tructure to prevent air
and moisture penetration. Accordingly, a problem is -to
adequately and suitably attach the membrane -to the exterior
wall assembly.
One can appreciate that it is not possible to
staple the membrane to the soft, pliable cellular plastic
polystyrene for adequate interface contact. Consequently,
the membrane is conventionally attached to the wood stud
framing of the wall substrate by stapling through the
membrane, in particular through the lapped joints thereof.
Decision as to the proper lapping over of the membrane,
the proper laps and the number of staple fixation points
is left to the specialized on-site workmen. This often
results into unappropriate fixation of the membrane and/or
in unadequate covering of the exterior wall surface by the
membrane.
As the polystyrene boards and the membrane are
both breathable to the diffusion of water vapor conveyed
from the inside to the outside, condensation within the
wall structure is thereby prevented. However, when the
membrane is not adequately applied on the exterior wall
surface for any of the above reasons, air and moisture can
penetrate into the wall to cause condensation and/or air
infiltration inside of the wall and eventually inside of
the house.
As the membrane is commonly available under the
form of rolls, another problem is that application of this
membrane on the exterior wall surface becomes very difficult
3~
in presence of h:ig~l winds. Moreover, hiyh wlnds can cause
tearing of the lapped joints of the membrane during cons-
truction.
OBJECT OF THE INVENTION
An object of the present invention is therefore
to provide a laminated, thermal insulation panel and a
thermal, wall insulation method which eliminate all of
the above discussed drawbacks of the prior art.
SUMMARY OF THE INVENTION
More specifically, according to the present
invention, there is provided a laminated, thermal insula-
tion panel comprising:
a board made of expanded polystyrene permeable
to water vapor;
a membrane laminated over one side of the poly-
styrene board, which membrane presents imperviousness to air
and moisture and permeability to water vapor; and
an adhesive applied between the membrane and
board for laminating the membrane on said one side of the
polystyrene board, said adhesive being applied in a pattern to ensure
permeability to water vapor and being compatible with both the polys-ty-
rene of the board and the material constituting the membrane,
so that the adhesive does not chemically attack the board
polystyrene and the membrane material whereby the water vapor
permeability of the board polystyrene and the membrane
material as well as the air/moisture imperviousness of the
membrane material are not affected by the adhesive.
Pre~erably, the membrane is made of non-woven,
spunbonded olefin, and the board of expanded, molded poly-
styrene.
9~7
In accordance with a preferred embod.iment of
the laminated, insulation panel oE the inven-ti.on, the pattern is
fo.nm~d by a plurality o:E s-trips o:E an adhesive co~lprising as elastomeri.c
base a blend of polybutene and styrene-isoprene-styrene
block copolymer, and as tackifying resins a blend of syn-
thetic hydrocarbon resins and rosin esters.
In accordance with the present invention, there
is further provided a method of thermally insulating the
exterior walls of a construction, such as a residential
house, comprising the steps of:
in-plant manufacturing laminated, thermal insu-
lation panels each obtained by laminating a membrane over
one side of a board made of expanded polystyrene, which
board and membrane are both permeable to water vapor and
which membrane is further impervious to air and moisture;
covering the outside of said walls with a
plurality of said insulation panels with the membrane
thereof at the exterior; and
sealing the joints between adjacen-t
ones of the panels with-an adhesive tape impervious
to air and moisture, which tape comprising an adhesive
surface applied on the membranes of the adjacent pa-
nels.
Preferably, the tape comprises permanent acrylic
adhesive with an oriented polypropylene backing.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, advan-tages and other features of
the present invention will become more apparent upon reading
of the following non restrictive description of a preferred
embodiment thereof, given in conjunction with the accompa-
nying drawings in which:
Figure 1 illustrates the structure of a laminated,
- 5 ~ 339~7
thermal insulation panel in accordance with the preserlt
invention; and
Figure 2 shows a method oE sealing ~he join-t
between two adjacent insula-tion panels both having a struc-
ture similar to that illustrated in Figure 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated in Figure 1, the laminated,
thermal insulation panel comprises (a) a board 1 made of
expanded, molded polystyrene of varying thickness which is
permeable to water vapor, and ~b) a membrane 2 which is
impervious to air and moisture, while being also permeable to
water vapor. The membrane 2 is laminated over one side of the board
1 by means oE a suitable adhesive applied in a pattern, for example longi-
tudinal strips 3 as shown in Figure 1, to ensure permeability to water
vapor. The adhesive should of course be compatible with both the
membrane 2 and the board 1, i.e. it does not attack chemi-
cally these board and membrane whereby the water vapor
permeability and the air/moisture imperviousness of the
same are not affected by the adhesive.
Each of the board 1, the membrane 2 and the
adhesive forming the strips 3 will now be described sepa-
rately by means of their characteristics and/or composition.
Of course, the different elements forming the insulation
panel have been selected for the best results, which selec-
tion results from a wide experimentation.
The board 1 is advantageously composed of an expanded,
molded polystyrene board. An example is the board of Type-l
manufactured and commerciallzed under the trademark ISOLOFOAM
by the Applicant company " LES PRODUITS ISOLOFOAM INC." .
The board 1 can vary in thickness depending on the desired
level of thermal insulation. Of course, the ISOLOFOAM board
is permeable to water vapor.
-- 6 --
Tests on a specimen oE ISOLOE'OAM expanded poly-
styrelle board oE Type-l have ~iven the following results:
Average thickness: 36~8 mm
Bulk density: 15.5 kg/m'
Hot surEace temperature: 3~ 8 C
Cold surface temperature: 13.7 C
Temperature difference: 21.1 K
Mean temperature of test: 24.3 C
Heat f],ux (through the
thickness): 21.52 W/m2
Thermal conductance: 1.020 W/(m2 K)
Thermal resistance: 0.9~0 m2 K/W
Thermal conductivity: 0.0375 W/(m K)
Thermal resistance by
unit thickness: 26.6 m K/W
These tests were performed with the specimen
placed horizontally in a 610 mm2 Heat Flow Meter Apparatus.
Heat flowed upwards through the specimen during testing.
Paper-backed glass fiber insulation was placed around the
perimeter of the plates of the Heat Flow Meter Apparatus
and of the specimen to reduce edge heat losses.
Additional tests carried out on a plurality of
specimen 25 mm thick of ISOLOFOAM expanded, molded polysty-
rene board of Type-l indicated the following results:
Average compressive strength: 80 kPa
Average Flexural strength: 193 kPa0
The membrane 2 is advantageously that manufac-
tured andcommercialized by the company DUPONT CANADA under
the trademark TYVEK. The TYVEK membrane is a sheet of Eine
synthetic fibers. More specifically, it is composed of
~3~ ~7
-- 7 --
non-woven, spunbonded olefill. As it i.s -totally synthetic,
it does not shrink nor ro-t. :[t resis-ts to tear and puncture,
it is permeable to water vapor but is impervious to air
and mois-ture. It therefore constitutes an air/moisture
barrier and accordingly an energy saving air barrier.
Some data given by the manufacturer concerning
the TYVEK membrane are the following:
Water vapor transmission rate
(g/100 in2 _ 24 hours~:51.30
Weight (lb/1000 ft2): 8.81
Rupture resistance (lb/in2): 105.00
Tearing resistance (lb) (lengthwise): 32.50
(transversal): 24.80
Porosity to the air - seconds: 7.60
Resistance to water (cm of water
pressure): 99.30
Thickness (mils): 6.10
The adhesive pattern is formed, in the example
of Figure 1, by a plurality of longitudinal strips 3 of
the adhesive SWIFT # 68468 manufactured and commercialized
by the company SWIFT adhesives, division of Reichhold Limited.
Some of its physical properties are the following:
ELASTOMERIC BASE: Blend of Polybutene and
Styrene-Isoprene-Styrene
block copolymer
TACKIFYING RESINS: Blend of synthetic hydrocarbon
resin and rosi.n esters
VISCOSITY: 12 - 15 poise
SOLIDS: 48 - 50~
FLASH POINT: - 18C (T.C.C.*)
SPECIFIC GRAVITY: 0.84 g/cc
* Abbreviation for Tag (actually Tagliabue) closed cup,
~g3~7
a type of flash point tes-t.
The SWIFT # 68468 adhesive is a solvent-base
pressure-sensitive adhesive of the permanent type including
a blend of synthetic rubber and of aliphatic/aromatic hydro-
carbons in a solvent. It has been formulated expressly
for applications requiring high peel strength and holding
power. The adhesive exhibits high shear strength over a
broad range of service temperatures as well as an aggressive
tack to a wide variety of surfaces.
In order to laminate the TYVEK membrane 2 on
the ISOLOFOAM polystyrene board of Type-l, it is not
sufficient to think to use an adhesive to glue the mem-
brane 2 on the board 1. Indeed, the following requirements
must be taken into consideration:
- the adhesive must not attack chemically
neither the membrane 2 nor the board 1 whereby these board
and membrane keep their physical characteristics, i.e. the
adhesive must be compatible with both the board 1 and mem-
brane 2;
- the adhesive must be applied in a pattern to
ensure permeability to water vapor in order to cause no reduc-
tion in water vapor permeability of-the overall insulation panel; and
- the adhesive must produce a suitable bond
between the membrane 2 and board 1.
2S Accordingly, one can appreciate that the selec-
tion of the adhesive cannot be effected without a great
quantity of tests and experimentations. Laminating the
membrane 2 on the board l is not an evident matter when it
is desired to obtain an insulation panel having the appro-
priate, desired characteristics.
The adhesive SWIFT # 68468 meets with these
requirements as it is non chemically aggressive when con-
fronted with the materials forming the board 1 and membrane
2 at temperatures under 70C. Accordingly, it bonds the
3~ 317
_ 9 _
two materials without altering their chemical or perEormance
charac-teristics.
Moreover, the adhesive SWIFT # 68~6~ dries
quickly. ~ccordingly, in the manufacture process, it is
not required to speed up cure by subjecting it to -tempera-
tures above 70C at which the adhesive attacks chemically
the polystyrene of the board 1.
The selected adhesive provides a bond between
the board 1 and membrane 2 strong enough that when the TYVEK
membrane is removed, it tends to remove the surface of the
polystyrene of the board 1. This results into stability
of laminate while slippage is not a problem. However, due
to the strong adhesion, re-adhesion properties are poor.
It has been experimented that strips 3 of a
width a = 12.7 mm lengthwise of the insulation panel at
a distance b = 100 mm between the centers of each pair of
adjacent strips 3 provide for good bond between the TYVEK
membrane 2 and the ISOLOFOAM board 1. Such a bond is strong
enough to prevent delamination problems or flapping situa-
tions.
A distance c = 3.2 mm is maintained between the
ends of the strips 3 and the corresponding edge of the board
1, as well as between the outer strips 3 and the respective
board edges.
Total covering of the surEace oE the board 1
with adhesive is not desirable due to potential negative
effects on the water vapor transmission rate through the
insulation panel.
It should also be pointed out that o-ther
types of adhesive having similar characteristics can even-
tually be used, for example pressure-sensitive adhesives
including natural rubber, or moisture cured urethane, etc.
Figure 2 illustra-tes a method of sealing the
joint 7 between two adjacent insulation panels 4 and 5 simi-
33~7
-- 10 --
lar to that of Figure l.
When the two panels 4 and S have been mounted
side by side as illustrated in Figure 2 Eor coveri.ng the
outside of an external wall o:E for example a residential
house, a self-adhesive tape 6 is applied on the outer sur-
face of -the two adjacent membranes 2 in order to seal the
joint 7 between the panels 4 and 5. As the TYVEK membranes
2 and the tape 6 form a system permeable to water vapor but
impervious to air and moisture, a surface presenting uniform
characteristics results from the latter operation.
A self-adhesive tape suitable for the above
purpose is that manufactured and commercialized under No.
Y 8086 by the company 3M CANADA INC. Such a tape is
constituted of permanent acrylic adhesive with an oriented
polypropylene backing.
Use of the laminated, thermal insulation
panel in accordance with the present invention for externally
covering the walls of for example a residential house results
in the following advantages:
- the TYVEK membrane can be in-plant laminated
mechanically and automatically. Before lamination, the
strips 3 of adhesive is applied on the ISOLOFOAM board
surface;
- the in-plant lamination of the insulation
panel results in savings in labor costs;
- the TYVEK membrane 2 constitutes a durable
exterior layer for the ISOLOFOAM board which improves the
puncture resistance and the durability of the expanded po-
lystyrene. The membrane also protects the polystyrene
board against direct exposure to the elements during cons-
truction. This enhances the quality of the final product;
- the TYVEK membrane greatly reduces air infil-
tration through the wall structure from the outside and
accordingly causes reduction in heating and cooling costs;
~293~17
- the TYVEK membrane additionally protects the
inside of the walls and -the polystyrene board against wind--
driven moisture from the outside. This, in particular,
maintalns -the high thermal resistance value oE the polysty-
rene whereby an energy eEficien-t insulation board is obtained;
- when boards as shown in Figure 1 are installed
to cover the outside of for example a residential house, and
using a self-adhesive tape 6 to seal the joints between
these boards, an air and moisture tight overall envelope
results as all the cracks and fissures are sealed; and
- the use of a laminated, thermal insulation
panel as illustrated in Figure 1 eliminates material losses
due to wind damage and wide lapped joints (commonly 4 to 12
inches wide), eliminates any development of loose flaps being
beaten and damaged by the action of strong winds, and eli-
minates all the guesswork on the on-site membrane applica-
tion and fixation by the workers. This of course results
in an enhanced quality of the final product.
During tests carried out on an insulation panel
as that shown in Figure 1 at pressure differences varying
from 25 Pa to 250 Pa, no delamination of the membrane 2 was
produced, and a reduction of 41~ of air leakage compared
with a polystyrene board with no laminated membrane was
observed.
During other tests on a specimen of insulation
panel similar to that of Figure l, comprising a polystyrene
board 1 50 mm thick, it was observed that both the adhesive
and TYVEK membrane had no significant effect on the permea-
bility of the Type-l ISOLOFOAM polystyrene board to water
vapor.
By way of example, with a board 1 of 33 mm
thick, and 47 mm thick, the thermal insulation provided by
the laminated panel is respectively R 4.7 and R 7Ø
Last of all, it should be pointed out that the
1;2~3~17
- 12 -
mos-t important advantage oE the laminated, -thermal klsula-
tion panel,according to the present lnvention,is that it
constitutes a barrier to air and moisture Erom the outside
to the inside, while it allows passage of water vapor from
the inside to the outside, to thereby prevent any condensa-
tion, moisture and air infiltration within or through the
wall assembly.
Although the present invention has been des-
cribed herein above by way of a preferred embodimen-t thereof,
it should be pointed out that any modification to this pre-
ferred embodiment, within the scope of the appended claims,
is not deemed to change or alter the nature and scope of the
present invention.
