U.S. patent application number 10/898451 was filed with the patent office on 2004-12-30 for adhesive tape structure for use with insulation jackets.
This patent application is currently assigned to Venture Tape Corp.. Invention is credited to Cohen, Lewis S., Litman, Gary.
Application Number | 20040265530 10/898451 |
Document ID | / |
Family ID | 32712780 |
Filed Date | 2004-12-30 |
United States Patent
Application |
20040265530 |
Kind Code |
A1 |
Cohen, Lewis S. ; et
al. |
December 30, 2004 |
Adhesive tape structure for use with insulation jackets
Abstract
A tape structure and/or closure system particularly useful with
cylindrical insulation segments for pipes. The tape structure
provides both a temporary and a permanent closure. The tape
structure includes a substrate and a layer of pressure sensitive
adhesive disposed on both sides of the substrate. One of the layers
of pressure sensitive adhesive is covered by a release liner, while
the other layer of pressure sensitive adhesive is exposed. The
exposed layer of pressure sensitive adhesive is applied to one of
either the underside of a flap covering a slit in the insulation
jacket, or to the outer surface of the insulation jacket. The
release liner is divided into two portions, one of which is narrow
with respect to the other portion. The narrow portion of the
release liner is removed, and a narrow strip of the second layer of
pressure sensitive adhesive is attached to the other of either the
outer surface of the jacket, or the underside of the flap to form a
temporary closure. When it is desired to insert a pipe into the
insulation segment, the temporary closure is broken by pulling the
flap away from the insulation jacket. The pipe is then inserted,
and a permanent closure is effected by removing the other portion
of the release liner and attaching the second layer of pressure
sensitive adhesive to the other of either the underside of the flap
or the outer surface of the insulation jacket.
Inventors: |
Cohen, Lewis S.; (Needham,
MA) ; Litman, Gary; (Framingham, MA) |
Correspondence
Address: |
Lawrence M. Green
Wolf, Greenfield & Sacks, P.C.
600 Atlantic Avenue
Boston
MA
02210
US
|
Assignee: |
Venture Tape Corp.
Rockland
MA
|
Family ID: |
32712780 |
Appl. No.: |
10/898451 |
Filed: |
July 23, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10898451 |
Jul 23, 2004 |
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10349802 |
Jan 23, 2003 |
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6783830 |
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Current U.S.
Class: |
428/40.1 |
Current CPC
Class: |
Y10T 428/24793 20150115;
Y10T 428/14 20150115; C09J 7/403 20180101; C09J 2301/124 20200801;
Y10T 428/24777 20150115; C09J 2301/204 20200801; C09J 7/38
20180101; Y10T 428/139 20150115; Y10T 428/1393 20150115; Y10T
428/149 20150115 |
Class at
Publication: |
428/040.1 |
International
Class: |
D21J 001/00 |
Claims
What is claimed is:
1. An elongated tape structure comprising: a substrate; a first
layer of a pressure sensitive adhesive disposed on one surface of
said substrate; a second layer of a pressure sensitive adhesive
disposed on another surface of said substrate; and a release liner
covering said second layer of pressure sensitive adhesive, said
release liner being formed of first and second portions separated
along a line extending in a direction of elongation of the tape
structure.
2. The tape structure as recited in claim 1 wherein said first
portion of said release liner is substantially wider than said
second portion as measured in a direction transverse to the
direction of elongation of the tape structure.
3. The tape structure as recited in claim 1 wherein said second
layer of pressure sensitive adhesive includes a gap with no
adhesive aligned with and extending along the line separating the
first and second portions of the release liner.
4. The tape structure as recited in claim 1 further comprising a
tab disposed on the first portion of the release liner for removal
of the first portion of the release liner separately from the
second portion.
5. The tape structure as recited in claim 2, further comprising a
tab disposed on the second portion of the release liner for removal
of the second portion of the release liner, separately from the
first position.
6. The tape structure as recited in claim 3, further comprising a
tab disposed on said second portion of said release liner along an
edge of said second portion facing said first portion of said
release liner and overlying said gap, said tab being graspable for
removal of said second portion.
7. The tape structure as recited in claim 6, further comprising a
tab disposed on said first position of said release liner along an
edge of said first portion facing said second portion of said
release liner and overlying said gap, said tab being graspable for
removal of said first portion from said second layer of pressure
sensitive adhesive. 8-25. (Canceled)
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to adhesive tape
structures, and more particularly to adhesive tape structures which
are used in conjunction with insulation for fluid conduits.
BACKGROUND OF THE INVENTION
[0002] Most heating and air conditioning units in dwellings,
commercial buildings and industrial plants include cylindrical
pipes which carry heated or cooled air or water or steam. In
addition, in industrial applications, pipes may be used to carry
these and other fluids. In most instances, particularly in more
severe climates, these pipes must be insulated to prevent freezing,
and/or to maintain the temperature of the fluid within the pipes,
especially where the pipes are disposed on the exterior of the
building structure.
[0003] Insulation segments may be used to insulate such pipes.
These segments typically are cylindrical in shape and include an
inner insulating layer surrounded by ajacket. In the center of the
segments is a cylindrical passageway extending axially or
longitudinally along the segment and having a diameter roughly
equal to the outside diameter of the pipe to be insulated. A
longitudinal slit is provided extending from one end of the segment
to the other. This slit may be opened to allow insertion of the
pipe therethrough and into the central passageway. A flap is
provided for covering the slit and for sealing the pipe within the
segment. Such segments typically extend along a pipe in an end to
end, abutting relationship to fully insulate and seal the pipe.
[0004] The inner insulating layer in each segment typically is
formed of a fiberglass or mineral wool, a foamed cellular
fiberglass or a rigid foam. The jacket which covers the insulating
layer typically is formed of a metal or metalized foil, and/or a
layer of kraft paper or the like. A preferred jacket material is an
All Service Jacket (ASJ), which has layers that include paper,
scrim, and aluminum foil and/or metalized polyester. Often, the
metal or metalized layers and/or paper layers are laminated
together to provide a weather-tight structure with a suitable tear
and tensile strength. Typically the flap which covers the slit is
merely an extension of the jacket and is formed of the same
materials.
[0005] Often, the flap and/or the outer surface of the insulation
jacket adjacent the slit is provided with a strip of adhesive or
adhesive tape to bond the flap to the outer surface of the jacket
to cover and seal the slit. The actual sealing of the flap to the
jacket typically occurs at the job site when the insulation is
installed. It is desirable, if not necessary, to keep the bonding
surfaces of the flap and the confronting, outer surface of the
jacket free from dirt and moisture to permit a tight seal. If the
seal is not satisfactory, "fish mouthing" can occur either as a
result of the breakdown of the bond between the adhesive strip and
the flap, or the bond between the adhesive strip and the outer
surface of the jacket. This breakdown can produce delamination or
disintegration of the jacket or the flap which can occur over a
period of a few weeks in a very damp environment, or over a period
of many months in less damp environments. If such "fish mouthing"
occurs, the insulation segments must be removed and replaced if the
desired level of protection is to be maintained "Fish mouthing" is
a particular problem on jobs for the United States Government,
since such "fish mouthing" does not meet its specifications and the
contractor may be required to return to the job site and repair the
damage at his or her own cost.
[0006] Moreover, hot melt adhesives typically are used to bond the
jacket to the inner insulating layer. The insulation segments
typically are still hot, and the adhesive is still soft and not yet
cured, when the insulation segments are placed in containers for
shipment. This quick placement in containers is necessary to
expedite the manufacturing and shipping process. The containers
into which the segments are placed tend to act as insulators and
retain the heat within the container maintaining the hot melt
adhesive in a softened condition for a prolonged period of time
after placement in the containers. As a result, the jacket can
separate from the inner insulating layer prior to cooling and
curing, and prior to arrival of the segment at the job site. Such
separated segments are not acceptable, and must either be discarded
or reattached. Obviously, this repair or replacement is very
costly. To overcome this problem, harder, more quickly curing
adhesives have been used to bond the jacket to the inner insulating
layer. However, since these harder adhesives do not permit movement
of the jacket with respect to the inner insulating layer with time
and under charging temperature and moisture conditions,
unacceptable dimpling of the jacket often occurs with such
adhesives.
[0007] One solution to the foregoing problems is to use soft, hot
melt adhesives or two component urethane adhesives and to
temporarily seal the flap to the outer surface of the insulation
jacket at the factory prior to shipping. This solution protects the
surfaces to be adhered to one another to minimize any "fish
mouthing" effects. This solution also wraps the jacket tightly
about the inner insulating layer, and prevents separation of the
structure during shipment because of the soft or uncured condition
of the hot melt adhesive. This solution also avoids most dimpling
effects. One existing structure that provides such a solution is
found in U.S. Pat. No. 4,157,410. In this structure, tape is
provided having either two or four layers of pressure sensitive
adhesive separated by release liners. When applied to the
insulation jacket and flap at the factory, the outer two release
liners are removed, exposing a layer of pressure sensitive adhesive
on either side of the structure which then temporarily bonds the
flap to the outer surface of the insulation jacket. When it is
desired to install the insulation segment at the job site, the flap
is separated from the outer surface of the jacket by prying apart
the structure along a central release liner in the structure that
separates two adhesive layers. The central release liner is then
removed, and the two adhesive layers are bonded together to
permanently seal the flap to the outer surface of the insulation
jacket.
[0008] Another solution is that disclosed in U.S. Pat. No.
5,104,701 assigned to the assignee of the present application. In
the closure system of this '701 patent, a tape contains a layer of
a low tack, pressure sensitive adhesive which bonds the tape on one
side to a strip either on the outer surface of the jacket on one
side of the slit or on the flap. The opposite side of the tape has
a release liner to which a high tack adhesive layer on the other of
the flap or the outer surface of the jacket is bonded to
temporarily bond the flap to the outer surface of the jacket. The
tape structure can be opened at the job site by peeling the
adhesive layer on the tape away from the strip. Once the flap is
opened, the release liner is removed and the high tack adhesive
layer on the flap or jacket may be permanently bonded respectively
to the outer surface of the jacket or the flap to provide a
permanent seal.
[0009] Another structure is found in U.S. Pat. No. 5,964,252, in
which an abridged release liner is provided to allow partial
exposure of the adhesive layer to achieve a temporary bond. This
temporary bond may be severed and the release liner may be
subsequently removed to achieve a permanent bond.
[0010] Another existing prior art structure in which an adhesive
layer is disposed on one of the flap and the outer surface of the
jacket is disclosed in U.S. Pat. No. 5,104,701. In one embodiment
of this prior art structure, an adhesive tape is provided which can
be bonded to the underside of the flap or to the outer surface of
the jacket, either at the job site or at the factory. This tape
typically includes a substrate having a layer of a pressure
sensitive adhesive disposed on both sides thereof. The adhesive
layer on one side of the substrate is bonded to the inside surface
of the flap or to the jacket, while the adhesive layer on the other
side of the substrate is covered by a release liner typically
having a silicon coated surface. This tape is either cut or
provided in strips which are adhered on the exposed adhesive side
to the underside of the flap or to the outer surface of the jacket.
At the job site, the insulation is wrapped about the pipe, the
release liner is removed from the adhesive layer on the other side
of the substrate, and the newly exposed adhesive layer then bonds
the flap to the outer surface of the jacket of the insulation
segment.
[0011] While the foregoing closure systems solve some of the
problems associated with cylindrical pipe insulation, these closure
systems are somewhat complicated, and therefore more expensive than
desired.
SUMMARY OF INVENTION
[0012] This invention relates generally to an adhesive tape
structure which may be used as a temporary closure and as a
permanent closure for a flap for an insulation segment for a fluid
conduit. The tape structure of this invention retains the
insulation segment in a closed condition after manufacture and
during shipment to prevent separation of the jacket and the inner
insulating layer. Moreover, the temporary closure maintains the
surfaces to be joined on the underside of the flap and the outer
surface of the jacket in a clean and dry condition. The temporary
seal is easily broken, and the permanent seal may be readily
effected at the job site after wrapping the insulation segment
about a pipe. The closure system of the present invention is
simpler and therefore less complicated to use and less expensive to
manufacture than some prior art closure systems.
[0013] In one aspect, this invention discloses an elongated tape
structure which includes a substrate, a first layer of a pressure
sensitive adhesive disposed on one surface of the substrate, a
second layer of a pressure sensitive adhesive disposed on another
surface of the substrate and a release liner which covers the
second layer of pressure sensitive adhesive. The release liner is
formed of first and second portions which are separated along a
line extending in a direction of elongation of the tape structure.
In one embodiment of this aspect, the first portion of the release
liner is substantially wider than the second portion as measured in
a direction transverse to the direction of elongation of the tape
structure. In another embodiment, the second layer of pressure
sensitive adhesive includes a gap having no adhesive which is
aligned with and extends along the line separating the first and
second portions of the release liner. In yet another embodiment, a
tab is disposed on the first portion of the release liner for
removal of the first portion of the release liner separately from
the second portion. In another embodiment, there is a tab disposed
on the second portion of the release liner for removal of the
second portion of the release liner separately from the first
portion.
[0014] In yet another embodiment, there is a tab disposed on the
second portion of the release liner along an edge of the second
portion facing the first portion of the release liner and overlying
the gap. The tab is graspable for removal of the second portion of
the release liner. In yet another embodiment of this aspect, there
is a tab disposed on the first portion of the release liner along
an edge of the first portion facing the second portion of the
release liner and overlying the gap. This tab is also graspable for
removal of the first portion of the release liner from the second
layer of pressure sensitive adhesive.
[0015] In another aspect, a temporary closure between a flap and an
outer surface of a jacket of an insulation segment is disclosed.
The jacket includes a slit extending in the direction of
elongation, and the flap is used to cover the slit. In this aspect,
the temporary closure includes a substrate, a first layer of a
pressure sensitive adhesive disposed on one lo side of the
substrate and adhered to a selected one of the underside of the
flap and an outer surface of the jacket, a second layer of a
pressure sensitive adhesive disposed on another side of the
substrate, and a release liner covering a first portion of the
second layer of pressure sensitive adhesive to allow a second
portion of the second layer of pressure sensitive adhesive to bond
to the other of the underside of the flap and the outer surface of
the jacket. In one embodiment of this aspect, the second portion of
the second layer of pressure sensitive adhesive is positioned on a
side of the slit in the insulation jacket facing a distal end of
the flap. In another embodiment, the release liner is removable
from the first portion of the second layer of pressure sensitive
adhesive after breaking of a bond between the second portion of the
second layer of pressure sensitive adhesive and the other of the
underside of the flap and the outer surface of the insulation
jacket, to allow the first portion of the second layer of pressure
sensitive adhesive to be bonded to the other of the underside of
the flap and the outer surface of the insulation jacket. In another
embodiment, the closure is spaced from a distal end of the flap to
provide an extension on the flap for grasping by a user to break
the bond between the second portion of the second layer of pressure
sensitive adhesive and the other of the underside of the flap and
the outer surface of the insulation jacket.
[0016] In yet another embodiment of this aspect, the first layer of
pressure sensitive adhesive is bonded to the underside of the flap,
and the closure covers the slit in the insulation jacket. In this
embodiment, the second portion of the second layer of pressure
sensitive adhesive is adhered to the outer surface of the jacket on
a side of the slit facing a distal end of the flap. In another
embodiment, the first layer of pressure sensitive adhesive is
bonded to the outer surface of the insulation jacket on a side of
the slit facing the distal end of the flap, and the second portion
of the second layer of pressure sensitive adhesive is bonded to the
underside of the flap. In yet another embodiment, the second
portion of the second layer of pressure sensitive adhesive is
substantially narrower in width than the first portion in a
direction transverse to the direction of elongation of the
insulation segment.
[0017] In another aspect of the invention, a method for insulating
a pipe is disclosed which uses an elongated cylindrical insulation
segment having an outer jacket, a slit in the outer jacket
extending in the direction of elongation of the segment to a
central passageway for insertion of a pipe into the central
passageway, and a flap for covering the slit in the outer jacket.
This method includes providing a tape structure having a substrate,
a first layer of a pressure sensitive adhesive disposed on one side
of the substrate, a second layer of a pressure sensitive adhesive
disposed on the other side of the substrate, and a release liner
covering the second layer of pressure sensitive adhesive, bonding
the tape structure along the first layer of pressure sensitive
adhesive to a selected one of the underside of the flap and an
outer surface of the insulation jacket, removing a narrow strip of
the release liner to expose a narrow strip of adhesive on the
second layer of pressure sensitive adhesive, and bonding the narrow
strip of adhesive on the second layer of pressure sensitive
adhesive to the other of the underside of the flap and the outer
surface of the outer jacket to provide a temporary seal for
shipment of the insulation segment to a job site. In one
embodiment, the narrow strip of adhesive is bonded to the other of
the underside of the flap and the outer surface of the insulation
jacket on a side of the slit facing a distal end of the flap. The
method of this aspect may also further include breaking the
temporary seal between the narrow strip of adhesive on the second
layer of pressure sensitive adhesive and the other the underside of
the flap and the outer surface of the outer jacket, inserting a
pipe into the central passageway through the slit, removing the
release liner from the second layer of pressure sensitive adhesive,
and adhering the second layer of pressure sensitive adhesive to the
other of the underside of the flap and the outer surface of the
outer jacket.
[0018] In another embodiment, the removing step includes grasping
the release liner by a tab and pulling the release liner from the
second layer of pressure sensitive adhesive. In another embodiment,
the step of bonding the tape may comprise adhering the first layer
of pressure sensitive adhesive to the underside of the flap, and
the step of bonding the narrow strip may comprise bonding the
narrow strip of adhesive on the second layer of pressure sensitive
adhesive to the outer surface of the outer jacket on a side of the
slit facing a distal end of the flap.
[0019] In another embodiment of the method of this invention, a
step of bonding the tape may comprise adhering the first layer of
pressure sensitive adhesive to the outer surface of the outer
jacket on a side of the slit facing the distal end of the flap, and
the step of bonding the narrow strip of adhesive may comprise
adhering the narrow strip of adhesive on the second layer of
pressure sensitive adhesive to the underside of the flap. In yet
another embodiment, the step of breaking the temporary seal
comprises grasping an extension of the flap and pulling the flap
away from the outer surface of the outer jacket. In yet another
embodiment of the method of this invention, the release liner may
be scored to separate the release liner into a narrow strip and a
second strip substantially wider than the narrow strip in a
direction transverse to the direction of elongation of the
insulation segment. This scoring step may be performed after the
step of bonding the tape and before the removing step. In yet
another embodiment, the method may comprise providing a gap in the
second layer of pressure sensitive adhesive. In another embodiment,
the release liner is scored along a line aligned with the gap in
the second layer of pressure sensitive adhesive to divide the
release liner into two strips, the narrow strip and the second
strip which is substantially wider than the narrow strip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The objects, advantages and features of this invention will
be more clearly appreciated from the following detailed
description, when taken in conjunction with the accompanying
drawings, in which:
[0021] FIG. 1 is a partial, cross-sectional view of a tape
structure illustrating one embodiment of the temporary closure
system of this invention;
[0022] FIG. 2 is a partial, cross-sectional view of a tape
structure illustrating another embodiment of the temporary closure
system of this invention;
[0023] FIG. 3 is a partial, cross-sectional view illustrating
application of the structure of FIG. 2 to an insulation segment to
produce a temporary seal;
[0024] FIG. 4 is a partial, cross-sectional view illustrating a
permanent seal on an insulation segment using the structure of FIG.
2;
[0025] FIG. 5 is a partial, cross-sectional view illustrating an
alternative embodiment of the application of the structure of FIG.
2 to an insulation segment to produce a temporary seal; and
[0026] FIG. 6 is a partial, cross-sectional view illustrating an
alternative embodiment of a permanent seal created on an insulation
segment using the structure of FIG. 2.
DETAILED DESCRIPTION
[0027] The present invention relates to a tape structure and/or a
closure system that provides a temporary closure that may be
transformed into a permanent closure. This structure or system has
particular applicability to flaps on insulation segments, including
insulation segments used in conjunction with pipes. It is to be
understood, however, that this closure system may be used in other
applications that require a temporary closure that can be
transformed into a permanent closure. The closure system of this
invention provides the advantages of prior art closure systems,
including protection of the surfaces to be finally bonded prior to
final closure so that the bond is dirt and moisture free, and, for
cylindrical insulation segments, including holding the jacket and
inner insulating layer together prior to curing of the adhesive to
prevent their separation. The closure system of this invention
includes a substrate with a pressure sensitive adhesive layer
disposed on either side, and a release liner covering one of the
pressure sensitive adhesive layers. The closure system is attached
to the underside of the flap at the factory by the other, exposed
adhesive layer. The release liner is scored such that a small strip
of the release liner may be removed at the factory to expose a
similarly narrow strip of pressure sensitive adhesive on the one
adhesive layer. The narrow strip of adhesive is then secured
directly to the outer surface of the jacket to temporarily attach
the flap to the outer surface of the jacket. At the job site, the
user can easily break the temporary seal provided by the narrow
strip of pressure sensitive adhesive to permit removal of the
remainder of the release liner. The now fully exposed one pressure
sensitive adhesive layer can then be bonded directly to the outer
surface of the jacket to provide a final and firm closure.
Preferably, the layer of pressure sensitive adhesive covered by the
release liner has a slight gap adjacent the score to facilitate
easy scoring and/or removal of the release liner. It is understood,
of course, that the narrow strip of adhesive could be bonded to the
flap, and the other adhesive layer could be bonded permanently to
the outer surface of the jacket adjacent the slit.
[0028] With reference now to the drawings, and more particularly to
FIG. 1 thereof, one embodiment of the structure of the tape or
closure system 10 of this invention will be described. Structure 10
includes at least one substrate 12, a first layer 14 of a pressure
sensitive adhesive disposed on one side of substrate 12, another
layer 16 of a pressure sensitive adhesive disposed on the other
side of substrate 12 and a release liner 18 covering one of layers
14 and 16. Release liner 18 is provided with a score 20 extending
along the length of structure 10 or into the page as shown in FIG.
1, or in the direction of elongation of structure 10. Score 20
divides release liner 18 into a narrow strip 22 and a wider strip
24. In the embodiment illustrated in FIG. 1, typically strip 24 of
release liner 18 may extend beyond substrate 12 and layer 16 a
short distance (i.e. to the right as shown in FIG. 1) to provide a
tab 25 which may be grasped by the user for removal of strip 24.
Similarly, strip 22 also may extend beyond layer 16 and substrate
12 on an opposite side of structure 10 (i.e. to the left as shown
in FIG. 1) to provide a tab 23 for gripping by a user for removal
of strip 22 independently of strip 24. In the embodiment shown in
FIG. 1, there is no gap in the pressure sensitive adhesive layer 16
aligned with score 20.
[0029] An alternative structure 11 is illustrated in FIG. 2. A
substrate 32 is provided with a first layer 34 of a pressure
sensitive adhesive disposed on one side, and a second layer 36 of a
pressure sensitive adhesive disposed on the other side thereof. A
release liner 38 covers one of layers 34 and 36. Release liner 38
includes a score 40 which divides release liner 38 into a wider
strip 44 and a narrower strip 42. In FIG. 2, the adhesive layer 34
or 36 adjacent liner 38 includes a gap 46 in which there is no
adhesive. Gap 46 is generally aligned with score 40. In this
embodiment, gap 46 permits release liner 38 to be scored using a
sharpened implement without engaging adhesive layer 34 or 36. When
the sharpened implement pierces liner 38, it does not touch any
adhesive which could slow down the scoring process, or gum up the
sharpened implement, as the sharpened implement passes along gap
46. In addition, gap 46 may provide a slight tab 47 on strip 42
which can be grasped by a user for removal of strip 42, if needed.
Similarly, there may be a tab 48 on strip 44 which is not adhered
by adhesive layer 34 or 36 which can be grasped by the user for
removal of strip 44. The provision of tabs 47 and 48 may render
unnecessary overlapping of release liner 18 with respect to layer
16 and substrate 12 to provide tabs 23 and 25, as illustrated in
FIG. 1, since strips 42 and 44 can be gripped along tabs 47 and 48.
It is to be understood, however, that overlapping portions of
strips 42 and 44 to provide tabs 23 and 25 could also be present in
structure 11 in the manner illustrated in FIG. 1, in addition to
tabs 47 and 48, or no tabs could be provided at all. In addition in
other embodiments, only tab 48 may be provided, or both tabs 25 and
48 could be present in the same structure, but not tabs 23 and
47.
[0030] Substrates 12 and 32 may be formed of any material typically
used for a substrate for an adhesive, such as a low density or high
density polyethylene, Nylon.RTM., polyester, polyethylene,
polypropylene or a metalized polyester or polyethylene.
[0031] Adhesive layers 14, 16, 34 and 36 may be formed of any
suitable pressure sensitive adhesive that is commercially available
and that is suitable for bonding to kraft paper or a metalized
foil, such as metalized biaxially oriented polypropylene, or to any
other materials that are typically used to form jackets on
insulation segments. One example is a pressure sensitive acrylic
adhesive such as that disclosed in U.S. Pat. No. 4,780,347, which
is specifically incorporated herein by reference, and which is
assigned to the assignee of the present application. This
particular adhesive is a pressure sensitive, acrylic adhesive
which, when cured, approaches a 100% acrylic compound in which
substantially all solvents have been removed. This adhesive can,
however, tolerate up to 1% solvents after curing and still perform
as desired. When cured, these adhesive layers typically have a
thickness of between about 1.0 and 5 mils and a coating weight of
about 5.5 to about 27.5 pounds per 1,000 square feet. This
particular acrylic adhesive is especially desirable, since it
remains tacky and usable at temperatures as low as minus 17.degree.
Fahrenheit and as high as 284.degree. Fahrenheit.
[0032] Release liners 18 and 38 can be any conventional release
liner suitable for use with an acrylic adhesive. A typical release
liner is a silicon coated, natural kraft paper release liner rated
at about 70 pounds per ream.
[0033] Score 20 and score 40 may be formed utilizing any
conventionally available cutting implement such as a knife, razor
blade or other sharpened cutting blade such as that found on a high
speed, coating line for manufacturing tape structures. With respect
to the embodiment of FIG. 2, it is important that score 40 be
aligned with gap 46. Therefore, preferably, score 40 is formed by a
sharpened blade that is found on the machinery used to form the
tape structure and that can be controlled to be within the closely
defined tolerances required by the narrow width of gap 46.
[0034] Where removal of strips 22 or 42 occurs during an automated
process at the factory, no gripable tab 23 or 47 may be required
for respective strips 22 or 42. In this instance, strips 22 and 42
are removed automatically by machinery which does generally not
require a griping tab.
[0035] An illustrative use of structures 10 and 11 in conjunction
with a typical insulation segment will now be described with
particular reference to FIGS. 3 and 4. While FIGS. 3 and 4 show
only structure 11, it is understood, of course, that structure 10
can be used in the same manner as structure 11, and that the
following description applies equally to structure 10. Like numbers
will be used for like parts, where appropriate. As described in the
background section above, a cylindrical insulation segment 51
typically includes an inner insulating layer 52 surrounded by
ajacket 54. A slit 56 extends through layer 52 and jacket 54 to
allow opening of the segment 51 for insertion of a pipe in a
central passageway 55. A flap 50, which is typically an extension
of jacket 54, passes over the exterior of slit 56 for closure of
slit 56 to seal a pipe (not shown) within insulation segment 51.
Typically, jacket 54, as well as flap 50, is formed of a metalized,
biaxially oriented polypropylene, although other layers of
materials, such as kraft paper, polyester scrim, polyester or
non-metalized polypropylene, could be employed in place of or in
addition to the biaxially oriented polypropylene layer. The
insulating layer 52 typically includes fiberglass or metal mineral
wool, foamed cellular fiberglass or a rigid foam.
[0036] Initially, as shown in FIG. 3, structure 10 or 11 is mounted
to the underside of flap 50 by pressure sensitive adhesive layer 14
or 34. Structure 10 or 11 typically is mounted to the underside of
flap 50 at a point at which flap 50 overlies slit 56. Also, in one
embodiment, as shown in FIG. 3, structure 10 or 11 is spaced
inwardly from the distal end of flap 50 toward a proximal portion
of flap 50 to form an extension 61 that may be gripped by a user to
break a temporary seal, as will be described. The application of
structure 10 or 11 to flap 50 typically is performed at the
factory, although it need not be. Thereafter, strip 22 or 42 is
removed and a resulting exposed thin strip of pressure sensitive
adhesive layer 16 or 36 is bonded directly to the outer surface of
jacket 54 adjacent slit 56 so that flap 50 covers slit 56. The
exposed width of adhesive layer 16 or 36 that is bonded to the
outer surface of jacket 54 is relatively narrow, so that this bond
can be easily broken by the user at the job site. Thereafter, this
insulation segment 51 is placed in a box for shipping.
[0037] At the job site, as illustrated in FIG. 4, the user breaks
the bond between adhesive layer 16 or 36 and the outer surface of
jacket 54, typically, by manually ripping flap 50 from jacket 54 by
grabbing extension 61. Since flap 50 is only bonded to jacket 54
along an area about the width of strip 22 or 42, and since
extension 61 of flap 50 extends beyond the area of flap 50 that is
bonded jacket 54 extension 61 can be grabbed by the user to provide
the leverage necessary to break the bond. Any damage done to flap
50 or to jacket 54 is minor and will be covered by flap 50 when
slit 56 is permanently sealed. Once the bond has been broken, a
pipe (not shown) is inserted through slit 56 until it resides in
passageway 55. Thereafter, slit 56 is tightly closed about the
pipe. The user then removes strip 24 or 44 by grabbing strip 24 or
44 by respective tab 25 or 48 and pulling strip 24 or 44 from
respective layer 16 or 36. The user then affixes the exposed layer
16 or 36 of pressure sensitive adhesive directly to the outer
surface of jacket 54 adjacent slit 56, as illustrated in FIG. 4,
for a final and permanent bond to seal slit 56. Since this part of
the outer surface of jacket 54 has been protected from
contamination by flap 50 during storage, it is dry and free from
dirt so that a secure and long lasting bond is provided.
[0038] It is to be understood that in the embodiment of FIGS. 3 and
4, while structure 10 or 11 is shown to be covering slit 56,
structure 10 or 11 instead may be placed in a position on the outer
surface of jacket 54 adjacent to but not covering slit 56,
preferably adjacent to but spaced from a distal end of flap 50.
Preferably, structure 10 or 11 is placed on a side of slit 56
facing the distal end of flap 50 and opposite the side facing a
proximal portion of flap 50, where flap 50 is attached to or
extends from jacket 54, so that flap 50 completely seals slit
56.
[0039] An alternative embodiment of the application of the tape
structure and/or closure system 10 or 11 of this invention to a
cylindrical insulation segment will now be described with reference
to FIGS. 5 and 6. Like numbers are used for like parts where
appropriate. In this embodiment, in contrast to that of FIGS. 3 and
4, structure 10 or 11 initially may be applied to the outer surface
of jacket 54, as opposed to the underside of flap 50. While FIGS. 5
and 6 specifically illustrate the use of structure 11 in
conjunction with a cylindrical insulation segment, it is to be
understood that the structure 10 of FIG. 1 could be used with an
insulation segment in the same manner as, or in place of, structure
11, and that the following description applies to both structure 10
and structure 11. In the embodiment of FIG. 5, exposed pressure
sensitive adhesive layer 14 or 34 is applied directly to the outer
surface of jacket 54. In this embodiment, structure 10 or 11 is
positioned adjacent slit 56 rather than covering slit 56 as shown
in FIG. 3 to allow access to slit 56 by a pipe. Moreover,
preferably, structure 10 or 11 is disposed on a side of slit 56
adjacent the distal end of flap 50, or on a side of slit 56
opposite the proximal portion where flap 50 is connected to or
extends from jacket 54. In this manner, slit 56 is fully covered by
flap 50 both for the temporary closure as illustrated in FIG. 5 and
for the permanent closure as illustrated in FIG. 6. This
positioning is preferred so that the flap fully covers and seals
slit 56 for both the temporary closure and the permanent closure,
and yet allows a user to open slit 56 to insert a pipe after
breaking of the temporary seal.
[0040] As illustrated in FIG. 5, strip 22 or 42 has been removed
from release liner 18 or 38, so that a narrow strip of pressure
sensitive adhesive layer 16 or 36 is bonded to the underside of
flap 50 to provide the temporary closure. Strip 24 or 44 of release
liner 18 or 38 remains in place to prevent permanent closure.
Preferably, extension 61 of flap 50 extends beyond structure 10 or
11 to allow flap 50 to be gripped to break the temporary seal at
the job site.
[0041] FIG. 6 illustrates the permanent seal formed at the job site
after the temporary seal illustrated in FIG. 5 has been broken. As
previously described, the temporary seal of FIG. 5 is broken by
gripping extension 61 and ripping flap 50 free of the outer surface
of jacket 54. Thereafter, slit 56 is opened sufficiently to allow
insertion of a pipe through slit 56 and into passageway 55, and
then slit 56 is closed about the pipe. Strip 24 or 44 is removed
such as by grasping respective tab 25 or 48 and pulling strip 24 or
44 free of adhesive layer 16 or 36. Flap 50 is then pulled tightly
over slit 56 and pressed against exposed adhesive layer 16 or 36
until a tight bond is achieved, as illustrated in FIG. 6. This
temporary closure of FIG. 5 and the resulting permanent closure of
FIG. 6, provide a secure, tight seal.
[0042] Some examples of dimensions of various components of
structures 10 and 11 will now be provided. It is understood,
however, that these exemplary dimensions are being provided for
purposes of illustration only, and are not intended to limit the
scope of the invention. In a typical embodiment, the approximate
width of strip 22 or 42 is about 11/4 inch, although wider or
narrower strips could be used. For the embodiment of FIG. 11, gap
46 in adhesive layer 36 is approximately 3/8 of an inch, although
wider or narrower gaps could be used. A typical size for tabs 47,
48, 23 and 25 is about 1/8 inch although wider or narrower tabs
could be provided. Structures 10 and 11 typically are provided in
tape form and a typical width is about 3 inches. However, wider or
narrower tapes or structures could be used. In addition, structures
10 and 11 typically are provided on a roll. If structures 10 or 11
are provided on rolls, release liner 18 or 38 should be provided
with a release coating on both sides, so that when the tape is
wrapped in a roll, release liner 18 or 38 will release from
respective pressure sensitive adhesive layer 14 or 34 to permit the
tape to be unrolled for use. Alternatively, a separate release
liner could be applied to pressure sensitive adhesive layers 14 and
34 to facilitate rolling or storage of the structure. In addition,
if structures 10 and 11 are provided in flat sheets as opposed to
rolls of tape, a release cover or coating must be applied to
adhesive layers 14 and 34 to protect the layers 14 and 34 during
storage.
[0043] Both structures 10 and 11 provide the desired protection to
the surfaces to be bonded and prevent the jacket from separating
from the insulation layer during shipping and storage. The final,
permanent closure completely seals slit 56 to form a long lasting,
permanent closure.
[0044] Modifications and improvements will occur within the scope
of this invention to those of ordinary skill in the art. The above
description is intended to be exemplary only, the scope of the
invention being defined by the following claims and their
equivalence.
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