Note: Descriptions are shown in the official language in which they were submitted.
CA 02296779 2005-12-22
JOINT SEAL WITH RESILIENT CAP
Field of the Invention
The present invention relates to the field of joint sealants, and provides an
expanding
foam sealant with a resilient cap.
Background of the Invention
Impregnated expanding foam sealants are sealants made from an open celled foam
that has been impregnated with an adhesive, an acrylic, an asphalt or the
like. Examples of
expanding foam sealants are GREYFLEXTM, 25VTM and 20HTM, each of which is sold
by
Emseal Corporation. These products are precompressed and sold in shrink-
wrapped batts
or on reels, and are cut-to-length, and inserted into a joint, wherein they
expand tightly
against the sides ofthe joint, to seal it. Additional adhesive may be applied
to the joint sides,
or to the sides of the expanding foam sealant before it is placed. Typically,
the foam is
precompressed to one-third to one fifth of its original volume, and only
allowed to expand
slightly when emplaced, to ensure a tight fit in a joint.
The present invention provides an improved form of expanding foam joint seal,
that
is provided with a resilient cap to protect the foam portion of the seal.
In a broad aspect, the present invention relates to a joint seal including a
body of
expanding impregnated foam, and a resilient cap having an upper surface and
side walls
depending downwardly therefrom, wherein said side walls are apertured, and
further
comprising a downward, longitudinally extending spine extending from said
lower surface.
-1-
CA 02296779 2005-05-20
Brief Description of the Drawings
In drawings that illustrate the present invention by way of example:
Figure 1 is an end view of a first embodiment of the present invention;
Figure 2 is a cross-sectional view of a cap for use in the present invention;
-1 a-
CA 02296779 2005-04-13
Figure 3 is a perspective view of another form of cap for use in the present
invention;
Figure 4 is a cross-sectional view of a joint seal according to the present
invention, using the cap of Figure 3;
Figure 5 is a cross-sectional view of a further form of joint seal according
to the
present invention;
Figure 6, which comprises Figures 6A, 6B and 6C, is a cross-sectional view of
a
further form of joint seal and caps according to the present invention;
Figure 7 is a perspective view of a cap similar to that shown in Figure 3,
illustrating effect of over-lengthening of cap side wall;
Figure 8 is a cross-sectional view of a further form of seal according to the
present invention;
Figure 9 is a cross-sectional view of an alternative form of cap for use with
the
seal of Figure 8;
Figure 10 is a cross-sectional view of a further form of seal according to the
present invention; and
Figure 11 is a cross-sectional view of a further form of seal according to the
present invention.
Detailed Description
Figure 1 illustrates the simplest form of the present invention which
essentially
comprises a cap 1 which can be placed over an expanding foam sealant 2. The
cap can
be either extremely elastic or of a more plastic nature. The cap, if extruded
or formed
from a relatively elastic (low modulus) material, may have the ability to
accept
sideways movement as a result of the expansion of the foam encapsulated by it.
Thus,
pre-compressed impregnated expanding foam sealant will tend to want to expand
and
utilize this expansion to increase the width across the top of the cap. The
cap is,
however, initially independent of the impregnated expanding foam sealant core,
and
thus has to be retained in position. This may be achieved by the use of a
ribbed inner
surface 3, as shown in Figure 2.
-2-
CA 02296779 2005-04-13
Moreover, the cap may be extruded directly onto the precompressed foam
sealant, for instance using a UV curable silicone, the selection of which will
be a matter
of choice to one skilled in the art. Such a cap will adhere strongly to the
expanding
foam core (made, in each case, of GREYFLEX, 25V or 20H) because it will tend
to
flow into the cells of the foam and form a mechanical anchor thereto when
cured.
Moreover, to enhance the attachment of the cap to the impregnated expanding
foam sealant, the cap may be provided with holes or voids 4 created or punched
along
both sidewalk thereof S, as shown in Figure 3. The voids, or holes, may be of
different
shapes or configurations. The purpose of the voids is to provide a mechanism
whereby
the impregnated expanding foam sealant may attach itself, through the voids,
to the
joint substrate and thus more securely attach the cap to the complete
assembly.
Alternatively, impregnated exapanding foam sealant, or other suitable flexible
material
such as closed cell foam, may be placed on the outer face of the punched walls
as a
'substrate' for the internal material pushing through the holes to bond to.
This outer
material may then be subsequently bonded to the substrate forming the walls of
the
joint. In other words, the impregnated expanding foam sealant may not be
required to
be attached primarily immediately to the joint substrate. The addition of
another layer
6 on the outer surface of the cap side walls (closest to the joint substrate)
would ensure
that the cap is retained in position more firmly. See Figure 4. The above
illustrates a
method or methods of more securely attaching the cap to the underlying
internal
cellular mechanism. Other methods will be a matter of choice to one skilled in
the art.
Alternatively, as shown in Figure S, the cap 1 may be extruded or formed from
the silicone group. In such a case, a silicone sealant 7 may be applied to the
inner walls
of the capping which is then place over the impregnated expanding foam sealant
2.
This will ensure that an adhesive bond is created between the silicone cap
extrusion
and the impregnated expanding foam sealant.
-3-
CA 02296779 2005-04-13
The above configurations essentially are provided to ensure that the cap
remains
in place during movement cycles of the joint and that the cap and the
impregnated
expanding foam sealant which it encapsulates do not separate from one another.
However, the configuration thus formed is limited by the elasticity of the
base material
forming the cap. To increase the movement capability of the total
configuration, the
cap may be provided with grooves 8 as shown in Figure 6A, B & C. The depth of
the
groove 8 (multiple grooves may be used) will then determine the extent of
movement
possible.
The side returns or walls of the cap should not be allowed to extend the full
depth of the impregnated expanding foam sealant in the joint. This
configuration may
inhibit correct attachment of the assembly to the walls of the joint and allow
the
migration of water or air between dissimilar materials that are not intimately
attached
to one another, as illustrated in Figure 7. This is particularly the case for
larger joints
that require a greater depth of impregnated expanding foam sealant to provide
support
for the capping in the event of pedestrian or vehicular traffic passing over
the joint. In
these cases, the external capping provided is optimally that of a T-section.
The central
spline 9 of the T will have impregnated expanding foam sealant on either side
immediately adjacent the top 10 of the T, thus providing the necessary support
(Figure
8). The T-piece may in addition be provided with flanges 11 on the lower
portion of
the central spline to more securely hold and position the impregnated
expanding foam
sealant (Figure 9).
From the above configurations, and especially from Figures 3, 6 and 8, it can
be
seen that the T-section, illustrated in Figure 8, and cap sections illustrated
in Figure 6,
may be combined to provide a configuration that meets the criteria of joint
stability,
transition support, joint movement, and waterproofing integrity, as shown in
Figure 10.
In this case, the central spline 12 of the T-piece is split into an elongated
groove
terminating in an endflange 11. A cap 10 and side wall returns 5 are
incorporated into
the format.
-4-
, CA 02296779 2005-12-22
For smaller joints existing, for instance in building facades and between
panelized
systems, the available depth of final seal configuration is limited. However,
thermal
movement considerations may be large in relation to joint size. In such
circumstances, the
depth of groove or split spline will determine the joint movement capability.
For larger movement joints such as trafficable expansion joints in parking
garages,
multiple grooves may require to be utilized, as illustrated in Figure 11. In
this type of joint,
layers of uncompressible foam 13 may be included. This permits a wider overall
joint to be
fabricated.
Thus, a range of profiles may be created based on the present invention that
can cater
for different sealant and movement joint configurations ranging from vertical
applications
(with small to extremely large joints) to horizontal applications (with small
to extremely
large joints) that must accept pedestrian or vehicular traffic.
Again, the support and recovery mechanism for the profiles is provided by the
choice
of impregnated expanding foam sealant. The impregnated expanding foam sealant
acts as
the return or recovery force for the profile - while the profile acts as the
main water or air
barrier to the system. The impregnated expanding foam sealant may be
interleaved where
necessary with a closed cell flexible foam or other flexible rigid material
that is
compressible and will reinforce the resilience and recovery of the internal
mechanism.
The cap for the joint seal of the present invention can be made of any
suitable
material, including polyethylene, polypropylene, natural or synthetic rubber
such as
SANTOPRENETM, silicone, or the like.
It is to be understood that the examples described above are not meant to
limit the
scope of the present invention, it is expected that the numerous variants will
be obvious to
one skilled in the field of joint seal design without any departure from the
-5-
CA 02296779 2000-O1-21
spirit of the invention. The intended claims, properly construed, form the
only
limitation on the scope of the invention.
-6-
