U.S. patent application number 11/004070 was filed with the patent office on 2005-04-14 for adhesive tape for masking.
Invention is credited to Gruber, George.
Application Number | 20050077003 11/004070 |
Document ID | / |
Family ID | 29269396 |
Filed Date | 2005-04-14 |
United States Patent
Application |
20050077003 |
Kind Code |
A1 |
Gruber, George |
April 14, 2005 |
Adhesive tape for masking
Abstract
An absorbent edge coating for masking tape and other masking
materials is herein disclosed. A masking tape according to the
present invention comprises a substrate having a top surface, a
bottom surface, and at least one masking edge. The bottom surface
of the substrate has an adhesive layer applied thereto. An
absorbent edge coating is applied to at least one masking edge of
the substrate so as to at least substantially prevent liquids
addressed to the at least one coated masking edge from being
absorbed into the substrate of the tape and from passing between
the bottom surface of the tape and a surface to which the tape has
been applied.
Inventors: |
Gruber, George; (Stillwater,
MN) |
Correspondence
Address: |
MOORE, HANSEN & SUMNER, PLLP
225 SOUTH SIXTH ST
MINNEAPOLIS
MN
55402
US
|
Family ID: |
29269396 |
Appl. No.: |
11/004070 |
Filed: |
December 3, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11004070 |
Dec 3, 2004 |
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10138683 |
May 3, 2002 |
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6828008 |
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Current U.S.
Class: |
156/280 ;
156/443 |
Current CPC
Class: |
Y10S 428/906 20130101;
Y10T 428/24793 20150115; Y10T 428/28 20150115; B05B 12/24 20180201;
Y10T 156/1052 20150115; Y10T 428/24777 20150115; C09J 2203/31
20130101; C09J 7/20 20180101; Y10T 428/24446 20150115 |
Class at
Publication: |
156/280 ;
156/443 |
International
Class: |
B32B 031/00; B65C
001/00 |
Claims
What is claimed is:
1. A method of manufacturing an adhesive tape having an absorbent
edge coating comprising: providing a substrate having a top surface
and a bottom surface; applying an adhesive layer to the bottom
surface of the substrate; rolling the substrate onto a cylindrical
core; cutting the substrate and the core onto which the substrate
is rolled into discrete rolls; and, applying an absorbent material
to an edge of a discrete roll of tape such that the absorbent
material is adhered to the edge of the substrate exposed on the cut
edge of the roll by the adhesive layer applied to the bottom
surface of the substrate.
2. The method of manufacturing an adhesive tape of claim 1 wherein
the absorbent material is a cross-linked polyacrylate polymer.
3. A method of manufacturing an adhesive tape having an absorbent
edge coating comprising: providing a roll of tape comprising a
substrate with an adhesive applied to a bottom surface thereof and
wound on a core, the roll of tape having an exposed edge; and,
applying an absorbent material to the exposed edge of the roll of
tape such that at least some of the absorbent material is adhered
to the adhesive applied to the bottom surface of the substrate at
the exposed edge of the roll of tape.
4. The method of manufacturing an adhesive tape of claim 3 wherein
the absorbent material is a cross-linked polyacrylate polymer.
5. A bi-directional tape dispensing device capable of applying tape
around and into corners of a first surface, wherein the first
surface may be adjacent to a second surface, said tape dispensing
device comprising: a frame having an alignment member extending
from said frame; a hub rotatably attached to said frame and adapted
for receiving a roll of tape, the roll of tape comprising an
elongate substrate having a top surface, a bottom surface, and at
least one masking edge, an adhesive layer applied to the bottom
surface of the substrate for adhering the tape to one of said first
and second surfaces, and an absorbent edge layer applied to the at
least one masking edge, and wherein when the roll of tape is
received by said hub, the at least one masking edge of said tape
aligns with an outer edge of said alignment member, and further
wherein said roll of tape may be pressed onto said hub with the at
least one masking edge of said roll of tape being oriented on said
bi-directional tape dispenser independent of a width of the roll of
tape and with no dependency on an inner edge of said roll of
tape.
6. The bi-directional tape dispensing device of claim 5 wherein the
absorbent edge layer is a cross-linked polyacrylate polymer.
Description
RELATED APPLICATIONS
[0001] This is a divisional application of U.S. patent application
Ser. No. 10/138,683, filed May 3, 2002, titled "ADHESIVE TAPE FOR
MASKING", which is commonly assigned, the entire contents of which
are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an improved adhesive tape
having an edge coating.
[0003] More specifically, the present invention relates to an edge
coating for masking tape and masking materials that improves the
masking ability of those materials.
BACKGROUND OF THE INVENTION
[0004] Adhesive tapes for masking are typically comprised of a
paper substrate having an adhesive layer applied to a bottom
surface thereof. In addition, some masking tapes have an upper,
liquid-resistant, or liquid-proof layer applied to an upper surface
of the substrate. A persistent problem with masking tapes of this
type is that the tape is typically only partially successful in
defining a clean masking edge or boundary between masked and
unmasked surfaces. For example, when an unmasked surface is
painted, it is common for paint to work its way into gaps between
the adhesive layer of the tape and the surface to which the tape is
applied. In addition, the paper substrate has a tendency to absorb
or wick moisture from the paint through the unprotected edge of the
tape substrate. This absorption causes swelling in the tape that
degrades the ability of the tape to form a tight seal with the
surface to which it is applied.
[0005] Yet another problem associated with masking tape and other,
similar masking products is that paint that overlies the edge of
the tape will cure in place and make it difficult to remove the
tape from beneath the edge of the layer of cured paint. In these
circumstances, tape can tear or worse, remove portions of the cured
paint, thereby necessitating touch up of the painted surface.
[0006] Accordingly, it is an objective of the present invention to
provide an edge coating that eliminates or at least minimizes the
movement of paint or other liquids past a boundary defined by a
masking edge of an adhesive tape or other masking product. It is
another object of the present invention to provide an absorbent
edge coating that will prevent or at least minimize liquids from
being wicked into the substrate of an adhesive tape or other
masking product. A final objective of the present invention is to
provide an edge coating for an adhesive tape or other masking
product that retards the curing of paints or other coatings applied
to a surface at a boundary between an unmasked area and a masked
area of a surface, thereby facilitating the clean release of the
adhesive tape or masking product from the surface to which it is
applied.
[0007] These and other objectives and advantages of the invention
will appear more fully from the following description, made in
conjunction with the accompanying drawings wherein like reference
characters refer to the same or similar parts throughout the
several views.
SUMMARY OF THE INVENTION
[0008] The objects of the present invention are realized in a
masking tape having a substrate with a top surface, a bottom
surface, a first edge, and a second edge. The bottom surface of the
substrate has an adhesive layer applied thereto and at least one of
the edges of the substrate, also referred to as a masking edge, has
an absorbent edge coating that substantially prevents liquids
addressed thereto from being absorbed into the substrate of the
tape and from passing between the bottom surface of the tape and a
surface to which the tape has been applied. The edge coating is
preferably a super absorbent polymer and has an absorbency that is
greater than that of the substrate of the tape. In this manner, the
edge coating reduces or substantially prevents the absorption of
liquids into the substrate and also prevents the movement of the
liquids beneath the tape. The super absorbent polymers of the edge
coating also absorb and retain excess liquids addressed to the
coated edge in such a manner as to retard the curing of the
liquids. By retarding the curing of the liquids at the edge of the
substrate, the absorbent edge coating facilitates the clean release
of the tape from the surface to which it has been applied and from
the remaining liquid applied to the surface.
[0009] In one embodiment, the substrate of the tape is fashioned of
a paper product such as a paper crepe ribbon though it is
envisioned that the tape may also be fashioned from polyethylene,
polyester, or other synthetic materials as well. To further prevent
the absorption of the liquids into the substrate of the tape, in
another embodiment a liquid resistant layer may be applied to the
top surface of the substrate of the tape. In yet another
embodiment, a liquid-proof layer applied to the top surface of the
substrate of the tape.
[0010] Another embodiment of the present invention may be
characterized as an improved masking tape for defining a boundary
between a masked area of a surface and an unmasked area of the
surface. Such a masking tape comprises an elongate substrate having
a top surface, a bottom surface, and at least one masking edge. An
adhesive layer is applied to the bottom surface of the substrate
for adhering the masking tape to the surface. An absorbent edge
layer is also applied to at least one masking edge of the substrate
to at least substantially prevent or minimize liquids applied to
the unmasked area of the surface from moving past the boundary on
the surface that is defined by the at least one edge of the
substrate to which the absorbent edge layer is applied. Preferably
the absorbent edge layer will be a super absorbent polymer capable
of absorbing water, oil based paint, latex paint, stains, glazes,
dyes, cleaning compounds, strippers, and solvents. Furthermore, the
absorbent edge layer applied to the at least one masking edge is
able to absorb and retain liquids applied thereto in such a manner
as to retard the curing of the liquid located at the boundary.
[0011] Yet another embodiment of the present invention may comprise
a roll of tape or a masking article that has had an absorbent edge
coating applied during the original manufacturing process, or may
comprise an absorbent edge coating that is applied to a roll of
tape or to a masking article immediately prior to its use. In one
embodiment, a method of manufacturing an adhesive tape that
includes an absorbent edge coating begins with the step of
providing a substrate that has a top surface and a bottom surface.
An adhesive layer is applied to the bottom surface of the
substrate. The substrate is subsequently rolled onto a cylindrical
core and cut into discrete rolls. The absorbent material that makes
up the edge coating is applied to at least one cut edge of the
discrete rolls such that the absorbent material is adhered to the
edge of the substrate exposed on the cut edge of the roll by the
adhesive layer applied to the bottom surface of the substrate.
[0012] Various embodiments of the present may be employed in
masking off a first area of a surface from a second area of the
surface by applying the tape to the surface such that the masking
edge of the tape is coincident with the boundary between the first
and second areas of the surface. An adhesive layer applied to the
bottom surface of the tape adheres the tape to the surface to which
it is applied. The absorbent layer on the masking edge of the tape
is preferably a super absorbent polymer.
[0013] Another embodiment of the present invention may also be
embodied in various masking materials used to define a boundary
between a masked area of a surface and an unmasked area of the
surface. Such masking materials comprise a substrate having a top
surface, a bottom surface, at least one edge, an adhesive layer
applied to at least a portion of the bottom surface of the
substrate for adhering the masking material to the surface, and an
absorbent edge layer that is applied to the at least one edge of
the substrate. The absorbent edge layer at least substantially
prevents liquids applied to the unmasked area of the surface from
moving past the boundary on the surface that is defined by the at
least one edge of the substrate to which the absorbent edge layer
is applied. Again, its is preferred that the absorbent edge layer
be made of a super absorbent polymer. These super absorbent
polymers absorb and retain liquids applied to the surface in such a
manner as to retard the curing of the liquid absorbed, thereby
facilitating the clean release of the edge of the tape from the
surface to which it has been applied and from the remaining liquid
applied to the surface.
[0014] Some embodiments of the present invention may also be
employed with a roll of tape that is to be applied for masking
purposes with a bi-directional tape dispensing device that is
capable of applying tape around and into the corners of a first
surface wherein the first surface may be adjacent to a second
surface. When so employed, such a tape-dispensing device may
comprise a frame having an alignment member extending from the
frame and a hub rotatably attached to the frame and adapted for
receiving a roll of tape. As will be appreciated the roll of tape
will comprise an elongate substrate having a top surface, a bottom
surface, and at least one masking edge. An adhesive layer is
applied to the bottom surface of the substrate for adhering the
tape to one of the first and second surfaces, and an absorbent edge
layer applied to the at least one masking edge of the substrate to
at least substantially prevent liquids applied to one of the first
and second surfaces from moving past a boundary on the first or
second. The boundary is defined by the at least one masking edge of
the substrate to which the absorbent edge layer is applied. The
roll of tape is received by the hub such that the at least one
masking edge of the tape is aligned with an outer edge of the
alignment member. Furthermore, the roll of tape may be pressed onto
the hub with the at least one masking edge of the roll of tape
being oriented on the bidirectional tape dispenser independent of a
width of the roll of tape and with no dependency on an inner edge
of the roll of tape.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a typical roll of masking
tape;
[0016] FIG. 2 is a cross sectional view of a prior art masking tape
taken along cutting lines 2-2 illustrating schematically the
multiple layers thereof;
[0017] FIG. 3 is a cross sectional view of a roll of masking tape
having an absorbent edge coating applied to a cut edge thereof;
[0018] FIG. 4 is a partial cross sectional view of a masking tape
having an absorbent edge coating of the present invention;
[0019] FIG. 5 is a schematic cross sectional view of the masking
tape of FIG. 4 illustrating one manner in which the masking tape
may be used;
[0020] FIG. 6 is a partial plan view of a surface that had been
masked with a masking tape having an absorbent edge coating on one
edge and another edge without such a coating;
[0021] FIG. 7 is a cross sectional view of the surface of FIG. 6
taken along cutting lines 7-7; and,
[0022] FIG. 8 is a close up partial cross sectional view of a
masking tape of the present invention illustrating how the
absorbent edge coating expands to absorb liquids applied to the
surface to which the masking tape is applied.
DETAILED DESCRIPTION
[0023] Although the disclosure hereof is detailed and exact to
enable those skilled in the art to practice the invention, the
physical embodiments herein disclosed merely exemplify the
invention, which may be embodied in other specific structure. While
the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by
the claims.
[0024] FIG. 2 illustrates a cross section of a standard, prior art
adhesive tape 10 of a type commonly used for masking. Tape 10 has a
middle layer or substrate 12 and an adhesive layer 14 applied to a
bottom surface of the substrate 12. In some instances, tape 10 may
have a top layer 16 applied to a top surface of the substrate 12
that is impervious or at least resistant to liquids. Tape 10 is
most often wound on a core 18 to form a roll 20 as illustrated in
FIG. 1.
[0025] The present invention comprises an adhesive tape 30 as
illustrated in FIGS. 3 and 4. Tape 30 has a substrate 32, an
adhesive layer 34, and an edge coating 36.
[0026] Tape 30 may also comprise an optional liquid proof or liquid
resistant top layer 38. The edge coating 36 may be applied to one
or both edges of the tape 30 and comprises an absorbent material
that acts to prevent or at least minimize the absorption of liquids
into the tape substrate 32 and the ingress of liquids between the
adhesive layer 34 and a surface to which the tape has been
applied.
[0027] The edge coating or edge layer 36 preferably has
super-absorbent properties such that the edge coating can absorb
many times its own weight in liquids brought into contact with the
edge 40 of the tape 30. At the very least, the edge coating 36 will
have a greater absorbency than the substrate 32 of the tape 30 and
will tend to draw liquids from the substrate 32 and will reduce or
prevent the absorption of liquids into the substrate 32. The
absorbency of the edge coating 36 also acts to overcome the
capillary action that can draw liquids such as paint beneath the
tape.
[0028] Super-absorbent materials are well known for their use in
diapers, as soil replacements, fire retardants, and in cabling
applications. Super-absorbent materials are also used in the
absorption and solidification of various types of wastewaters and
sludges, including radioactive waste. Super-absorbent materials are
typically solid, granular cross-linked polyacrylate polymers that
rapidly absorb and retain large volumes of aqueous and other types
of solutions and liquids. While virtually any type of
super-absorbent material may be used in conjunction with the
present invention, sodium polyacrylate has proven to be
particularly useful. Sodium polyacrylate is a chemical that
consists of very long carbon chains that are bonded together with
sodium atoms found in the center of the molecule. This structure,
through osmosis, is able to absorb and retain many times its own
weight. The liquids absorbed by a super-absorbent material are
entirely encapsulated within the long chain molecule that makes up
the super-absorbent material and these liquids are only slowly
released therefrom. This slow release, coupled with the complete
encapsulation of the liquids, retards the curing of liquids such as
paint.
[0029] Other super-absorbent materials that are available today and
which may be used with the present invention include, but are not
limited to cellulosic or starch-graft copolymers and synthetic
super-absorbent materials made from polyacrylic acids, polymaleic
anhydride-vinyl monomers, polyvinyl alcohols, and
polyacrylonitrile.
[0030] As tape 30 may be used in many different masking
applications, including, but not limited to painting, staining,
glazing, shellacking, varnishing, lacquering, cleaning, and
stripping, the edge coating 36 of tape 30 may be called on to
absorb many different types of liquids to prevent these liquids
from being absorbed by the substrate 32 of tape 30 or entering
between the adhesive layer 34 and a surface S to which the tape 30
has been applied. Liquids that may be absorbed by the edge coating
36 may include, but are not limited to, paint (oil, latex, milk,
whitewash etc.), shellac, varnish, lacquer, thinners, cleaners,
strippers, water, and solvents of many types. The term "liquids" as
used herein is to be construed broadly to include all of the
aforementioned substances as well as any other substances, liquid
or merely viscous, whose use may require the use of masking tape or
other masking products.
[0031] FIG. 5 illustrates how tape 30 may be used in a painting
application. In FIG. 5, tape 30 has been adhered to a surface S
such that its left edge 40a is coincident with a boundary B between
a first, unmasked area A1 and a second, masked area A2. Paint P is
applied with a brush 42 to the unmasked area A1. Paint P is applied
right up to and at times over boundary B thereby covering
substantially all of area A1. When paint P reaches the boundary B
formed by the edge 40 of the tape 30, the liquid paint P at the
edge 40 of the tape that would otherwise be absorbed by the
substrate of the tape 30 or pass between the tape 30 and the
surface S is absorbed by the edge coating 36 of tape 30. Note that
in the Figures, edge coating 36 is not illustrated to scale and
therefore it is to be appreciated that though the super-absorbent
materials from which the edge coating 36 are made will swell when
liquids such as paint P are absorbed, the expanded edge coating 36
does not expand significantly away from the edge 40 of the tape 30
and will not mar the final finish of the paint P. This result is
best seen in FIGS. 6 and 7.
[0032] The super absorbent materials of the edge coating 36 retain
the paint P away from the atmosphere such that the paint P within
the edge coating 36 does not fully cure. Indeed, the paint P at the
boundary B defined by the coated edge 40a of the tape 30 is also
kept somewhat uncured by the slow release of the uncured paint P
and its solvents that had previously been absorbed by the edge
coating 36. Consequently, the less-than-fully cured paint P at the
boundary B will cleanly release from the tape 30 when the tape 30
is removed from the surface S. This also results in clean, linear,
and smooth boundary B between the masked and unmasked areas of
surface S.
[0033] FIGS. 6 and 7 depict results obtained with a standard
adhesive tape 30 of a type commonly used for masking having one
coated edge 40a and one uncoated edge 40b. As can be seen from FIG.
6 (and FIG. 7) the left boundary B formed by the coated edge 40a of
tape 30 is linear and smooth whereas the right boundary B formed by
the uncoated edge 40b of tape 30 is jagged and irregular. FIG. 8
illustrates close up how the edge coating 36 of tape 30 absorbs the
paint P as the paint P contacts the edge coating 36. Conversely,
the uncoated edge 40b of tape 30 permits excess paint P to work its
way onto the masked area A2 beneath the adhesive layer 34, to be
absorbed into the substrate 32 of the tape 30 and to form a bead 44
of dried paint over the boundary B and onto the upper layer 38 of
the tape 30.
[0034] FIG. 3 illustrates one method of applying an edge layer 36
of super absorbent materials 46 to a roll 20 of tape 10, 30. Tape
10, 30 is typically formed in large sheets (not shown) many times
wider than the roll illustrated in FIGS. 1 and 3. These sheets of
tape 10, 30 are rolled onto an elongate core (not shown) to form an
elongate roll of tape 10, 30. The elongate roll of tape 10, 30 is
then cut into rolls 20 of predetermined widths. The cut sides 48,
50 of the rolls 20 of tape 10, 30 have adhesive from the adhesive
layers 14, 34 exposed thereon. The side or sides 48, 50 of each
roll 20 of tape are then pressed into a quantity of super absorbent
material 46 that has been previously deposited in a container 52.
The grains of the super absorbent material 46 are adhered to the
edges 40 of the tape 10, 30 by the adhesive of the adhesive layers
14, 34 of the tape. While the super absorbent material 46 may
occasionally be applied to the sides 48, 50 of the rolls 20 of tape
in an inconsistent manner, it must be remembered even a small
amount of the supper absorbent material 46 is needed to enable the
present invention. It is to be understood that other, alternative
methods may be employed to apply the super absorbent materials 46
to the edges 40 of the tape 10, 30. These methods may include, but
are not limited to, spraying, dipping, sprinkling, or painting the
super absorbent materials onto the tape 10, 30.
[0035] The present invention may be readily employed with masking
products and devices other than masking tapes having an absorbent
substrate. The present invention may be beneficially employed with
adhesive tapes having polyethylene, polyester, or other synthetic
substrates. These adhesive tapes may or may not further comprise a
liquid-proof or liquid-resistant top layer or coating. In addition
to adhesive tapes, it is to be understood that paper or synthetic
drop cloths or masking sheets may also benefit from the present
invention. Paper and synthetic drop cloths or masking sheets are
thin sheets of material that are used in masking large areas during
such operations as painting and cleaning with solvents. These drop
cloths and masking sheets are typically much wider than the
adhesive tapes used in masking objects and may have adhesives over
their entire bottom surface, over only a portion of their bottom
surface, or not at all.
[0036] While it is preferred to apply an edge coating 36 to a roll
20 of tape 30 prior to the sale of the tape 30 in the normal course
of trade, it is to be further understood that super absorbent
materials 46 may be applied to virtually any adhesive tape or other
masking product at a work site. In this case, the super absorbent
materials 46 would be placed in a container and applied to the
adhesive tape or other masking materials as needed. An additional
benefit of the present invention is that the addition of an
absorbent edge coating 36 to any adhesive tape, expensive or cheap,
will greatly enhance the performance of that tape.
[0037] Tape 30 may be applied by hand, as where a user of the tape
manually adheres the tape 30 to a surface such that at least one
masking edge of the tape is coincident with a boundary between an
unmasked area A1 and a masked area A2. Alternatively, tape 30 may
be applied using a tape dispensing mechanism such as that described
in U.S. Pat. No. 6,302,177 issued to the inventor of the present
invention on Oct. 16, 2001. U.S. Pat. No. 6,302,177 is hereby
incorporated by reference.
[0038] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the claims.
* * * * *