Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to wallboard tapes used in
covering joints between adjacent drywall panels. The tapes of
this type have long been used in drywall constructions to produce
a smooth joint between abutting wall board panels, suitable for
subsequent painting or wall papering.
In a typical application, the dr~wall panels are nailed to
the studs such that the panels abut or are closely spaced from
each other at the area of the stud. It i6 impossible to avoid
cracks between the edges of adjacent panels and the wallboard
tape is one of the elements used in providing a smooth transition
over such crack.
The cracks are usually filled by a crack filling substance.
This is known to be done by two distinct methods. Both of them
use a reinforcing tape. Merely filling the crack between two
gypsum boards with a plaster of caulking compound would
eventually result in a new crack. This is due to ~tructural
movements in walls and ceilings which occur for a variety of
reasons. The use of a reinforcing tape or some similar product is
, therefore inevitable.
The first, and by far the most prevalent method of taping
and filling the cracks, utilizes a paper tape devoid of adhesive
coating. The tape is supplied in rolls about 2" wide. It is
cemented over the joint utilizing drywall joint compound as the
cement or adhesive US Patent 2,814,080, Tvorik et al, presents an
example of the method. This procedure is known as "taping
joints".
The drywall joint compound used in securing the tape to the
joint comes in two basic forms. The first is a water based air
drying compound which dries and sets as a consequence of
evaporation of water which is one of its constituents. Such
drying is a lengthy procedure which takes about 12 - 24 hours
before the joint may be top coated by paint or the like. The
second group of compounds used in securing the paper tape sets
chemically, as a result of a chemical reaction. The chemically
setting joint compounds are usually plaster based. They set in
about 15 minutes to a few hours and can then be top coated. One
of the disadvantages of this second group is in that the
application is messy. Furthermore, it requires relatively
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accurate estimates of time within whioh to apply the given batch
of the compound b~fore it begins to set. The final product is
difficult to ~and. The advantage of chemically setting substance6
is in that they are tougher and less likely than the water ba~ed
substances to develop cracks again.
From the standpoint of the pre~ent invention, it ~hould be
noted that in the first method the reinforcing tape i~ a plaln
paper tape devoid of an adhssive or the like coating.
The crack filling compound i8 not lnstrumental for holding a
reinforcing tape in place in the ~econd known method, wherein an
open me6h of gla~ fibre ~S Patont 4.5~2~Q04- E~aDs st al.. or a
paper tape S Pa~eat 4.042.739. E~l et 1 is coated with a
pressure aensitive glue and i8 applied over the crack prior to
the application of the crack filling ~ubstance. Im~edi~tely after
the application of euch reinforcing tape, either of the two ~oint
compounds can be appl~ed over and through the me~h of the tape to
fill in the crack. The glass fibre scrlm iB provided with a
pressure sensitive adhesive layer. The tape i8 adhered to
drywalls over 2 joint, then the joint compound is applied over
the mesh. The compound passes directly through the mesh and
bonds to the edges of the adjacent drywall panel~. If the paper
tape i6 used, the compound stAys only on the 6urface of the tape
and of the ad~acent drywall panelfi.
It iB noteworthy that the manufacturers of the glass fibre
reinforcing tapes recommend the use of the tape with chemically
setting compound~, mainly for the reason that they provide a
tougher joint wh~ch is les~ likely to impair the final product by
recurrence of the cracking which occurs within and beyond the
mesh of glass fibre. The cost of the glags fibre mesh is
relatively high. The use of the chemically setting compounds i~
di 8 advantageous for reasons 9xpl ained above.
Attempts have been made to alleviate the problsms as~oclated
with the use of the glass fibre ~esh by using a paper tape with
pres~ure sensitive adhe~ive. The bonding of the t~pe to drywall
panels was improved. However, it was di~covered that cracka tand
to occur at the edge~ of the tape when the ~oint compound dries.
This was found to be the case particularly when the tape was used
in conjun¢tion with the otherwise preferred water based joint
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compound.
It is an object of the present invention to further advancethe art of reinforcement tapes for drywall joints and, in
particular, to provide advantages of both of the paper and glass
S fibre me6h tapes while eliminating or at least reducing most of
their disadvantages.
In general terms and in one aspect thereof, the invention
provides a wallboard tape for covering the joint between ad;acent
drywall panels, said wallboard tape comprising: (a) an elongated
base strip made from paper and having two opposed side edges
defining the width of the base strip; (b) one face of the base
strip ~eing provided with an adhesive layer of a pres~ure
sensitive adhesive; (c) the layer of pres6ure 6ensitive adhesive
being covered with a peel-off backing strip means; (d) the base
strip being provided with perforations disposed in a pattern
extending over the entire length of the base strip.
In another aspect but still defining the invention in
general terms, a wallboard tape is provided for covering the
joint between adjacent drywall panels, said wallboard tape
. 20 comprising: (a) an elongated ba~e strip made from paper and
having two opposed side edges defining the width of the base
! strip; (b) one face of the base 6trip being provided with an
layer of a pressure sensitive adhesive; (c) the adhesive layer
being covered with a peel-off backing sheet means; (d) said peel-
off backing sheet means including a first portion and a 6econd
portion; (e) 6aid first and second portion covering each ,a part
of the adhesive layer extending along one of the side edges of
the base; (f) backing ~eparation means a6~0ciated with said
backing sheet means to allow removal of one of said portions
while leaving the other portion applied to the respective part of
~ the adhesive layer.
The invention will now be described by way of two preferred
embodiments with reference to the accompanying diagrammatic,
drawings. For the sake of more clearly showing the features of
the invention, the drawing~ are not to scale, particularly in
cross-sectional representations. In the drawings:
Figure 1 is a top plan view of a first embodiment of the
invention;
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Figure 2 i6 6ection II-II of Figure 1;
Figure 3 i6 a top plan view of a 6econd embodiment of the
invention; and
Figure 4 i6 6ection IV-IV or Figure 3.
Turning fir~tly to the embodiment of Fig6. 1 and 2,
reference numeral 10 generally denotes a wallboard tape. The tape
10 has infinite length and includes an elongated base strip 11
made of drywall joint paper. The width of the tape is about 2"
and the thickness of the paper base i8 about .005" to about
.010". The underside of the ba6e strip 11 as viewed in Figure 2
is provided with a layer 12 of pressure 8 ensitive adhesive (PSA).
Typically, the adhesive is polymeric adhesive. It usually cover6
the entire undersurface of the ba6e strip even though two
6eparate 6tripes, one along each edge of the base strip 11 would
also be acceptable.
The layer 12 of the PSA is covered by a peel-off backing
sheet means generally designated with reference numeral 13. The
backing 6heet 13 has a centrally disposed, longitudinally
extending line of weakne66 1~ which subdivides the backing 6heet
means 13 into a fir6t portion 15 and a second portion 16.
The outside edges 17, 18 of the backing sheet portions 15,
16 are disposed slightly beyond the adjacent 6ide edges 19, 20 of
the base strip 11.
Each of the first and 6econd portion6 15, 16, covers that part of
the adhesive layer 12 which is disposed along one of the 6ide
edges .
~ he line of weakne66 14 i6 coincident with the longitudinal
axis of the tape. It allow6 removal of one portion 15 of the
backing strip while the other portion 16 may remain in place for
a sub6equent removal.
-- The base 6trip 11 is provided with perforation. The
repre6entation of Figure 1 pre6entæ a preferred pattern of the
perforation for the purpose of providing the object of the
pre6ent invention.
The perforation ha6 a central part 21 which extends
centrally of the tape and is formed by a 6ingle row of
equidi6tantly spaced circular openings 22 having the diameter of
about 3/16". The 6pacing of the centre6 of the openings 22 i6
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about 1/2~.
The perforation further include6 two 6ide parts ~3 and 24
both of which are compri6ed of 6maller diameter (about 1/8")
circular openings. One side part 23 i8 di6posed along one edge
l9, of the ba6e 6trip 11 in a zig-zag pattern. The width of the
pattern i6 about 5/16~'. The spacing between openings ~ or 26
adjacent in the direction parallel with elongation of the tape i8
about 3/8".
Another embodiment of the invention i~ ~hown in Figs. 3 and
4. Here, again, the tape 30 ha6 a paper base ctrip ~1 Of the
structure generally corresponding to that of the fir6t
embodiment. The base sheet i8 likewise provided with a PSA layer
32 which i6 covered over by peel-off backing trip means
cumulatively decignated with reference numeral ~. A6 in the
first embodiment, the backing 6trip mean6 33 i6 6ubdivided into
two portion6 34 and ~. Contrary to the arrangement of Fig. 4,
; the portion 35 overlaps portion 34 at the centre of the tape 30.
The protection of the outer edges of the portion6 34 and 35
beyond the respective side edge6 of the paper tape 31 i8 imilar
to that of the fir6t embodiment described.
The 6econd embodiment i8 intended to show that other wayQ of
;l a 6plit backing of the base 6trip and a different perforation can
be made without departing from the ~cope of the invention.
In Fig6. 3 and 4, the ba6e 6trip 31 i6 provided with tiny
perforations 36 di6po6ed in an equidi6tant pattern over the width
of the tape 30. They pre6ent another embodiment or perforation
, producing the de6ired result.
The seaond embodiment utilize6, in addition to the line of
weakne6s provided by the 6plit of ths backing, a crea6e line 37
- 3~ in the ba6e 6trip 31. The line 37 further facilitate6 the
- folding of the tapa along the longitudinal axi6 to provide for
convenient application of the tape at the corner6.
In use, the tape i8 applied to a joint in the 6ame fashion
a6 the known glas6 fiber me6h, as de6cribed above. When working
with the fir6t embodiment, the joint compound can be trowelled
over the tape and through the perforation6 into the gap between
the adjacent boards. The second embodiment is 6uitable in
in6tallation6 whsre it i6 de6ired to apply the ~oint compound
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only over the 6urface of the tape without the need for filling
the gap between the panel 6 .
The split backing 6h0et 13, 33 prs~ents added convenience ln
applying the tape in the corners, between two abutting panels
disposed at right angles to each other. The tape i8 first folded
upon itself along the centreline, with the backing out. One of
the two backing portions 15 - 16 or 34 - 35 i6 then stripped off
to expose the re6pective stripe of the adhe~lve layer 12, 32.
The tape thus preformed iB then applied to one of the two
drywall panels. Then the second backing portion 16 - 15 or 35 -
34 can be removed and the second half of the tape applied to the
other board by simply unfolding the tape. The crease line 37
provides added convenience in thi6 re6pect. However, the
embodiment of Figures 1 and 2 i8 no less convenient to fold,
apparently due to ths line 14 of weaknesR in the backing sheet
13.
~ hose skilled in the art will appreciate that the described
embodiments may be further modified within the 6pirit of the
present invention. Accordingly, we wish to protect by letters
patent which may is6ue on the present application all such
embodiments as reasonably fall within the scope of our
contribution to the art.
