U.S. patent application number 10/899569 was filed with the patent office on 2006-01-26 for non-loading abrasive article.
Invention is credited to Ehrich J. Braunschweig, Ian R. Owen, Thomas W. Rambosek, Edward J. Woo.
Application Number | 20060019579 10/899569 |
Document ID | / |
Family ID | 34972799 |
Filed Date | 2006-01-26 |
United States Patent
Application |
20060019579 |
Kind Code |
A1 |
Braunschweig; Ehrich J. ; et
al. |
January 26, 2006 |
Non-loading abrasive article
Abstract
An abrasive article and methods of making and using the same are
disclosed. The abrasive article includes a particle impermeable
back-up pad attached to an abrasive disc. The abrasive disc
includes a plurality of perforations therethrough. When the
abrasive article is moved and contacted against a workpiece, debris
from the workpiece is captured between the back-up pad and
workpiece.
Inventors: |
Braunschweig; Ehrich J.;
(Woodbury, MN) ; Woo; Edward J.; (Woodbury,
MN) ; Owen; Ian R.; (River Falls, WI) ;
Rambosek; Thomas W.; (Woodbury, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
34972799 |
Appl. No.: |
10/899569 |
Filed: |
July 26, 2004 |
Current U.S.
Class: |
451/28 |
Current CPC
Class: |
B24D 9/08 20130101; B24B
55/102 20130101; B24D 9/10 20130101 |
Class at
Publication: |
451/028 |
International
Class: |
B24B 1/00 20060101
B24B001/00 |
Claims
1. An article comprising: a back-up pad having a particle
impermeable major surface; and an abrasive disc removably attached
to the impermeable major surface, the abrasive disc including a
plurality of perforations therethrough.
2. The article of claim 1, wherein the perforations arc distributed
over the entire disc.
3. The article of claim 2, wherein the perforations are
substantially uniformly distributed over the entire disc.
4. The article of claim 1, wherein the perforations are distributed
over an annular section of the disc.
5. The article of claim 1, wherein the perforations are of
substantially uniform size.
6. The article of claim 1, wherein the disc is attached to the
back-up pad via a hook and loop arrangement.
7. The abrasive article of claim 6, wherein the hooking members are
on the back-up pad and the loop members are on the disc.
8. The article of claim 1, further including an adhesive layer
between the back-up pad and the disc.
9-10. (canceled)
11. The article of claim 1, wherein the plurality of perforations
is less than 14.
12. A method of sanding comprising: providing an article comprising
a back-up pad having a particle impermeable major surface; an
abrasive disc removably attached to the impermeable major surface,
the abrasive disc including a plurality of perforations
therethrough; moving the abrasive article; and contacting a
workpiece with the abrasive article.
13. The method of claim 12, wherein the perforations arc
distributed over the entire disc.
14. The method of claim 13, wherein the perforations are
substantially uniformly distributed over the entire disc.
15. The method of claim 12, wherein the perforations are
distributed over an annular section of the disc.
16. The method of claim 12, wherein the perforations are of
substantially uniform size.
17. The method of claim 12, wherein the disc is attached to the
back-up pad via a hook and loop arrangement.
18. The method of claim 17, wherein the hooking members are on the
back-up pad and the loop members are on the disc.
19. The method of claim 12, further including an adhesive layer
between the back-up pad and disc.
20-22. (canceled)
23. The method of 12, wherein the method of sanding includes wet
sanding.
24. The method of claim 12, wherein the method of sanding includes
dry sanding.
25. The method of claim 12, wherein moving the abrasive article
includes manually moving the abrasive article.
26. The method of claim 12, wherein moving the abrasive article
includes moving the abrasive article with a powered device.
27. A method of making an article comprising: removably attaching a
particle impermeable back-up pad to a disc, wherein the disc
includes a plurality of perforations therethrough.
28. The method of claim 27, wherein the perforations are
distributed over the entire disc.
29. The method of claim 28, wherein the perforations are
substantially uniformly distributed over the entire disc.
30. The method of claim 27, wherein the perforations are
distributed over an annular section of the disc.
31. The method of claim 27, wherein the perforations are of
substantially uniform size.
32. The method of claim 27, wherein the disc is attached to the
back-up pad via a hook and loop arrangement.
33. The method of claim 32, wherein the hooking members are on the
back-up pad and the loop members are on the disc.
34. The method of claim 27, further including an adhesive layer
between the back-up pad and the disc.
35-36. (canceled)
37. The method of claim 26, wherein the powered device is an
electric sander.
Description
FIELD
[0001] The present disclosure relates generally to abrasive
articles, and more particularly to back-up pad/abrasive disc
combinations.
BACKGROUND
[0002] Back-up pads are used in the abrasives field to support an
abrasive article, such as a disc or sheet during abrading. These
abrasive articles can be in various forms, such as a disc, a sheet,
or a polygon and, may optionally, contain holes or slits to aid in
dust extraction. The back-up pad includes a generally planar major
surface, to which the abrasive article, such as a disc or sheet,
may be attached. Although back-up pads may be hand held, back-up
pads are more commonly used in conjunction with a powered abrading
apparatus such as electric or pneumatic sanders.
[0003] Abrasive discs and sheets (hereinafter collectively "discs")
may be attached to a back-up pad in various ways. One attachment
method includes an abrasive disc having pressure sensitive adhesive
(PSA) on one surface thereof, such that the abrasive disc may be
adhered to the major surface of the back-up pad. The major surface
of the back-up pad may have, for example, a smooth foam, vinyl, or
cloth surface to facilitate attachment of the abrasive disc. An
example of such a back-up pad is available from 3M Company of St.
Paul, Minn., under the designation "STIKIT" brand back-up pad. An
example of an abrasive disc for attachment to that back-up pad is
available from the same company under the designation "STIKIT"
brand abrasive disc.
[0004] A second type of back-up pad includes a major surface having
a plurality of hooks projecting therefrom. The hooks are adapted to
engage certain structures provided on the back face of an abrasive
disc to releasably attach the disc to the back-up pad. An example
of such a back-up pad is available from the 3M Company of St. Paul,
Minn., under the designation "HOOKIT" brand back-up pad, and an
example of an abrasive disc for attachment to that back-up pad is
available from the same company under the designation "HOOKIT"
brand abrasive disc. Alternatively, the back-up pad major surface
can include engaging structures to cooperate with hooks on an
abrasive disc. An example of such an assembly is available from 3M
Company under the designation "HOOKIT II" brand back-up pad and
abrasive disc.
SUMMARY
BRIEF DESCRIPTION OF THE DRAWING
[0005] The present disclosure will be further explained with
reference to the appended Figures, wherein like structures are
referred to by like numerals throughout the several views, and
wherein:
[0006] FIG. 1 is a section view of an example embodiment of a
back-up pad and abrasive disc combination according to the present
disclosure;
[0007] FIG. 2 is an example embodiment of a disc according to the
present disclosure;
[0008] FIG. 3 is example embodiment of a disc according to the
present disclosure;
[0009] FIG. 4 an example embodiment of a disc according to the
present disclosure;
[0010] FIG. 5 an example embodiment of a disc according to the
present disclosure;
[0011] FIG. 6 an example embodiment of a disc according to the
present disclosure
[0012] FIG. 7 an example embodiment of a disc according to the
present disclosure; and
[0013] FIG. 8 an example embodiment of a disc according to the
present disclosure.
DETAILED DESCRIPTION
[0014] Generally, the invention of the present disclosure is
directed to an abrasive article including a back-up pad removably
attached to an abrasive disc. Within the context of this
disclosure, removably attached means that the disc is secured to
the back-up such that it will not detach during an abrading
operation, but can be removed from the back-up pad via manual
means, e.g., taken off by hand. The abrasive disc includes a
plurality of perforations or holes therethrough for allowing
passage of debris (swarf, dust, particles, metal, etc.) from a
workpiece into the area or volume between the back-up pad and the
abrasive disc.
[0015] FIG. 1 illustrates an exemplary article 105 including
back-up pad 110 with an abrasive article 130 attached thereto.
Abrasive layer 111 of article 130 comprises a plurality of abrasive
particles 120 attached to a flexible backing 112 by adhesive
coating 121. The backing 112 has a front side 113 and a backside
114. Attachment layer 115 is provided as a pressure sensitive
adhesive layer (PSA) to releasably attach the abrasive article 130
(layers 111 and 112) to the facing layer 116 provided on the front
surface 117 of molded foam layer 118. Foam layer 118, on its rear
surface 119, is attached to a rigid metal backing plate 122. A
threaded stud 123 is fixed in a known manner to the back side of
the rigid backing plate 122 to allow attachment of the back-up pad
110 to a suitable tool or drive means (not shown) capable of, for
example, rotatably driving the pad 110 and the article 130 around
the longitudinal axis of threaded stud 123. The back-up pad 110 is
substantially impermeable to matter that is removed during the
abrading process.
[0016] Various perforation (interchangeably, also holes)
configurations in the abrasive disc can be used with the particle
impermeable back up pad. FIG. 2 illustrates a 5-hole disc 230,
which is typically 3-8 inches (76.2-203.2 mm) in diameter. The
holes 250 are spaced-regularly around the disc 230, at about 72
degree intervals. Such discs are available under the trade
designation "DUST-FREE SANDING DISCS--5 HOLE," from 3M Company, St.
Paul, Minn. FIG. 2 illustrates an 8-hole disc 330, which is
typically 3-8 inches (76.2-203.2 mm) in diameter. The holes 350 are
spaced-regularly around the disc 330, at about 45 degree intervals.
Such discs are available under the trade designation "DUST-FREE
SANDING DISCS--8 HOLE," from 3M Company, St. Paul, Minn.
[0017] While the above-described discs include circular holes (or
perforations), other shapes can be used, either singly or in
combination. Referring to FIG. 4, an exemplary disc 420 includes
alternating rectangular shaped perforations 452 arranged regularly
around the disc 420. Triangular perforations 452 are placed between
the rectangular perforations near the periphery of the disc
420.
[0018] FIG. 5 illustrates an 8-perforation disc 520, which is
typically 3-8 inches (76.2-203.2 mm) in diameter. The perforations
550 are spaced-regularly around the disc 520, at about 45-degree
intervals. The perforations 550 have an end 551 near the periphery
of the disc 520 and extend inwardly along a diameter of the disc
520 to a second end 553 near the center of the disc 520.
[0019] FIG. 6 illustrates an 8-perforation disc 630, which is
typically 3-8 inches (76.2-203.2 mm) in diameter. The perforations
650, 652 are spaced-regularly around the disc 630. The perforations
650, 652 are arcuate and have a circularly-shaped end 651, 653 near
the periphery of the disc 630 and extend inwardly to a second
cusp-shaped end 655, 657 near the center of the disc 630.
[0020] FIG. 8 illustrates a 13-perforation disc 820, which is
typically 3-8 inches (76.2-203.2 mm) in diameter. Eight
perforations 850 are spaced-regularly around the disc 820 near the
disc 820 periphery, at about 45-degree intervals. The remaining
five perforations 850 include a center hole and an X-shaped layout
of the remaining four perforations surrounding the center hole.
[0021] Other possible arrangements include the holes or
perforations distributed over the entire disc, both uniformly and
non-uniformly. The holes or perforations can also be distributed
over annular sections of the disc. The perforations on a given disc
can be of uniform size, or can be of various shapes and sizes.
[0022] To increases the amount of debris that can be accommodated
between the disc and the back-up pad, means for accumulating the
debris can be optionally included. For example, the back-up pad can
have an undulating surface, wherein the low points in the surface
will allow more debris to be trapped. The back-up pad can also
include cavities, which allows debris to be trapped. An interface
pad can also be included between the back-up pad and the disc,
adding further debris holding capacity. An exemplary interface pad
is available under the trade designation "SOFT INTERFACE PAD,"
available from 3M Company, St. Paul, Minn.
[0023] The back-up pad of the invention can be used in any of a
variety of desired abrading applications so long as it is properly
designed to meet the requirements of the given abrading
application. The foam material and mixing proportions of the
components of the foam should be formulated to meet the needs of
the desired abrading application.
[0024] It is within the capability of one of ordinary skill in the
art to select the back-up pad to meet the requirements of the
abrading for which the pad is used. It is to be understood that the
term abrading, and its variants, as used herein are meant to
include operations used to reduce or refine a workpiece surface
through frictional contact between the workpiece surface and an
abrasive article, such as grinding, sanding, finishing, cleaning or
polishing operations. These abrading applications can vary widely
from final polishing of ophthalmic lenses to heavy stock removal of
metal parts. These abrading applications can also involve either
abrading by hand or abrading with a machine as the mode of driving
the abrasive article in motion. The abrading motions may include a
linear motion, random motion, rotary motion, oscillation, random
orbital motion, combinations thereof or the like.
[0025] The shape of the foam back-up pad may be a square, triangle,
rectangle, oval, circle, pentagon, hexagon, octagon, polygon, or
any other suitable shape. The diameter for a circular back-up pad
ranges from about 0.5 to 50 inches (1.25 cm to 127.0 cm), typically
1 to 30 inches (2.5 cm to 76.2 cm). The length and/or width of the
back-up pad can range from about 0.05 to 50 inches (0.13 cm to
127.0 cm), typically 1 to 30 inches (2.5 cm to 76.2 cm). In some
instances, a coated abrasive article will overhang the back-up pad
by a very slight amount, i.e., typically less than 0.1 inches (0.25
cm), preferably less than 0.05 inches (0.13 cm). The thickness of
the foam body member generally will range from between about 0.2 cm
to 7.0 cm typically 0.5 cm to 5.0 cm, and preferably between 1.0
cm. to 3.0 cm.
[0026] The foam back-up layer, as used in most abrading
applications, will be molded to present a pair of substantially
parallel spaced major surfaces or faces. Referring to FIG. 1, the
front face 117 of the foam back-up pad 110 provides a surface upon
which a pad-facing layer 116 can be provided. Examples of materials
useful for forming the front facing layer include cloth, nonwoven
substrates, treated cloth, treated nonwoven substrates, polymeric
films and the like. Examples of preferred front facing materials
include loop fabric, cloth sheeting, vinyl sheeting, hooks, nylon
coated cloths, vinyl coated nonwovens, vinyl coated cloth, hook
faced materials, and the like. The loop fabric can be a knitted
loop, brushed loop, a chenille stitched loop, and the like. The
polyurethane material of the foam layer 118 is bonded to the
pad-facing layer 116 and can be hardened in-situ on the pad facing.
For instance, a polyurethane material can be foamed directly to the
back side of a pad facing such as loop fabric, thereby adhering to
the pad facing. Alternatively, the front facing material can be
adhesively bonded to the polyurethane foam. If the polyurethane is
foamed onto the front facing material, the front facing material
preferably is first sealed to prevent undesired excessive
penetration of the foam therethrough.
[0027] If the foam back-up pad is intended to be used in machine
driven applications, it will typically have some type of mechanical
attachment system opposite the side of the loop fabric to secure
the back-up pad to the machine. One such system comprises rigid
backing plate 122 fixed to the rear surface 119 of the foam back-up
pad 110 with threaded stud 123 fixed to the plate 122 (e.g., by
welding) for attachment of the foam pad 110 to a drive motor, such
as described in U.S. Pat. No. 4,844,967 (Goralski), incorporated
herein by reference. Backing plate 122 is affixed (e.g., by rivets)
to a larger diameter fiberglass plate (not shown) or an equivalent
member, and the foam surface 119 is bonded directly to the
fiberglass to thereby affix the mounting system to the back-up pad
110. Any of a variety of systems or means can be provided for
detachable coupling of the foam pad 110 to different types of drive
motor assemblies. Such means are known in the art and may include,
for example, central concentric openings extending through the foam
and the backing plate and accommodating the threaded end of a
headed bolt, with the bolt head abutting the surface of the backing
plate affixed to the foam with the head of the bolt positioned in
the central opening of the foam and the threaded end of the bolt
engaging the drive member of a drive motor assembly. For random
orbital applications, the support member may contain a threaded
studded or other attachment system for mounting onto the machine.
Other means that can be provided to adapt the back-up pad for
operation with drive mechanisms include those disclosed in U.S.
Pat. No. 4,631,220 (Clifton), incorporated herein by reference. It
will be understood that the invention is not limited by the
specific mounting system employed, and those skilled in the art
will appreciate that the specific mounting system employed for use
with a specific back-up pad will depend on the type of tool to be
used with the pad.
[0028] For manual abrasive operations held in the hand, various
shapes or configurations of foam back-up pads may be utilized. Two
such types include hand pads and foamed back-up pads used on long
planing boards. The strength and other physical properties required
for these manual abrasive operations is less than those for random
orbital applications where the strength and physical property
requirements of the foam become much more significant. The physical
properties of the foam depend on the end use application. As the
back-up pad is used in abrading applications, there can be a manual
grip handle associated with it.
[0029] In some instances, it is preferred to incorporate a pressure
sensitive adhesive onto the backside of the abrasive article so
that the backing of the abrasive article can be secured to the
facing layer of the foam back-up pad. Representative examples of
pressure sensitive adhesives suitable for this invention include
latex crepe, rosin, acrylic polymers and copolymers e.g.,
polybutylacrylate, polyacrylate ester, polyvinyl ethers, e.g.
polyvinyl n-butyl ether, alkyd adhesives, rubber adhesives, e.g.,
natural rubber, synthetic rubber, chlorinated rubber, and mixtures
thereof. The preferred pressure sensitive adhesive is an
isooctylacrylate: acrylic acid copolymer.
[0030] Alternatively, a hook and loop type attachment system may be
employed to secure the abrasive article to the facing of the foam
back-up pad. The hook fabric may be on the backside of the abrasive
article with hooks on the front side of the back-up pad. Otherwise,
the hooks may be on the backside of the abrasive article with the
loops on the front side of the back-up pad. This hook and loop type
attachment system is further described in U.S. Pat. No. 4,609,581
(Ott); U.S. Pat. No. 5,254,194 (Ott et al.); U.S. Pat. No.
6,579,162 (Chesley et al.); U.S. Pat. No. 5,505,747 (Chesley et
al.); U.S. Pat. No. 5,607,345 (Barry et al.); and U.S. patent
publication No. 03-0159363-A1 (Chesley et al.); each of which is
incorporated herein by reference. The opposite exposed front side
of the abrasive article has an abrasive coating that is responsible
for the abrading action.
EXAMPLES
[0031] The following materials were obtained from 3M Company, Saint
Paul, Minn. As noted, some materials were subsequently modified for
evaluation purposes. [0032] "AD1": A P320 grade alumina, resin
bonded, 5-inch (12.7 cm) diameter abrasive disc, commercially
available under the trade designation "210U P320 STIKIT DISC";
[0033] "AD2": A 5-hole P320 grade alumina, resin bonded, 5-inch
(12.7 cm) diameter abrasive paper disc, commercially available
under the trade designation "210U P320 STIKIT DUST-FREE DISC",
wherein a single center-hole, 13/8 inch (3.5 cm) diameter, was die
punched out of the abrasive film disc; [0034] "AD3": A P400 grade
alumina, resin bonded, 5-inch (12.7 cm) diameter abrasive disc,
commercially available under the trade designation "210U P400
STIKIT DISC"; [0035] "AD4": A 5-hole P400 grade alumina, resin
bonded, 5-inch (12.7 cm) diameter abrasive paper disc, commercially
available under the trade designation "210U P400 STIKIT DUST-FREE
DISC", wherein a single center-hole, 13/8 inch (3.5 cm) diameter,
was die punched out of the abrasive film disc; [0036] "AD5": A P400
grade alumina, resin bonded, 5-inch (12.7 cm) diameter abrasive
paper disc, commercially available under the trade designation
"210U P400 HOOKIT II DISC"; [0037] "AD6": A 5-hole P400 grade
alumina, resin bonded, 5-inch (12.7 cm) diameter abrasive paper
disc, commercially available under the trade designation "210U P400
HOOKIT II DUST-FREE DISC", wherein a single center-hole, 13/8 inch
(3.5 cm) diameter, was die punched out of the abrasive film disc;
[0038] "AD7": A P400 grade alumina, resin bonded, 6-inch (15.2 cm)
diameter abrasive paper disc, having a stearate antiloading
supersize, commercially available under the trade designation "216U
P400 FRE-CUT HOOKIT II DISC"; [0039] "AD8": A 6-hole P400 grade
alumina, resin bonded, 6-inch (15.2 cm) diameter abrasive paper
disc, having a stearate antiloading supersize, commercially
available under the trade designation "216U P400 FRE-CUT HOOKIT II
DUST-FREE DISC" [0040] "AD9": A 9-hole P400 grade alumina, resin
bonded, 6-inch (15.2 cm) diameter abrasive paper disc, having a
stearate antiloading supersize, commercially available under the
trade designation "216U P400 FRE-CUT DUST-FREE HOOKIT II DISC";
[0041] "AD10": A P500 grade alumina, resin bonded, 5-inch (12.7 cm)
diameter abrasive film disc, commercially available under the trade
designation "360L P500 HOOKIT II"; [0042] "AD11": As per "AD10",
wherein a single center-hole, 13/8 inch (3.5 cm) diameter, was die
punched out of the abrasive film disc; [0043] "AD12": A 5-hole P500
grade alumina, resin bonded, 5-inch (12.7 cm) diameter abrasive
film disc, commercially available under the trade designation "360L
P500 HOOKIT II DUST-FREE DISC", wherein a single center-hole, 13/8
inch (3.5 cm) diameter, was die punched out of the abrasive film
disc; [0044] "AD13": A P1000 grade alumina, resin bonded, 6-inch
(15.2 cm) diameter abrasive film disc, commercially available under
the trade designation "260L P1000 HOOKIT II DISC"; [0045] "AD14": A
6-hole P1000 grade alumina, resin bonded, 6-inch (15.2 cm) diameter
abrasive film disc, commercially available under the trade
designation "260L P1000 HOOKIT II DUST-FREE DISC"; [0046] "AD15": A
P1000 grade alumina, resin bonded, 6-inch (15.2 cm) diameter
abrasive film disc, commercially available under the trade
designation "260L P1000 STIKIT DISC"; [0047] "AD16": A 6-hole P1000
grade alumina, resin bonded, 6-inch (15.2 cm) diameter abrasive
film disc, commercially available under the trade designation "260L
P1000 STIKIT DUST-FREE DISC"; [0048] "AD17": A P1000 grade alumina,
resin bonded, 6-inch (15.2 cm) diameter abrasive film disc,
commercially available under the trade designation "260L P1000
HOOKIT DISC"; [0049] "AD18": A 6-hole P1000 grade alumina, resin
bonded, 6-inch (15.2 cm) diameter abrasive film disc, commercially
available under the trade designation "260L P1000 HOOKIT DUST-FREE
DISC"; [0050] "AD19": A P320 grade alumina, resin bonded, 5-inch
(12.7 cm).times.3-inch (7.6 cm) rectangular abrasive paper sheet,
commercially available under the trade designation "334U P320
HOOKIT II"; [0051] "AD20": As per "AD19", wherein 13 holes of
1/8-inch (0.32 cm) diameter, in an evenly distributed
3.times.3/2.times.2 array, were die punched out of the abrasive
sheet, having the hole pattern as illustrated in FIG. 8; [0052]
"BP1": Back-up pad having pressure sensitive adhesive as a means
for attaching abrasive discs, available under the trade designation
"STIKIT LOW PROFILE DISC PAD"; [0053] "BP2": Back-up pad having
hooks as a means for attaching abrasive discs in a hook and loop
mechanical fastener system, available under the trade designation
"HOOKIT LOW PROFILE DISC PAD"; [0054] "BP3": Back-up pad having
loops as a means for attaching abrasive discs in a hook and loop
mechanical fastener system, available under the trade designation
"HOOKIT II DISC PAD"; [0055] "BP4": As per backup pad BP1, wherein
a polypropylene mask having a pressure sensitive adhesive coated
macro structure, 0.317 mm.times.0.317 mm.times.0.35 mm height, and
0.156 mm channels between macro structures, was laminated to the
face of the back up pad; [0056] "BP5": Hand-held back-up pad having
pressure sensitive adhesive as a means for attaching abrasive
discs, available under the trade designation "HOOKIT II CENTER
WATER FEED FOAM DISC PAD"; [0057] "BP6": A hard hand sanding block,
23/4-inch (7.0 cm).times.5-inch (12.7 cm), commercially available
under the trade designation "HOOKIT II HAND BLOCK"; [0058] "TP1": A
mild steel test panel coated with a grey primer, commercially
available under the trade designation "URO 1140S" from E. I. DuPont
de Nemours Company, Wilmington, Del.; [0059] "TP2": A mild steel
test panel coated with a powder primer, commercially available
under the trade designation "PCV 70118" from PPG Industries,
Pittsburgh, Pa.; [0060] "TP3": A mild steel test panel coated with
a urethane clearcoat, commercially available under the trade
designation "DCU 2021" from PPG Industries; [0061] "TP4": A mild
steel test panel coated with a primer, commercially available under
the trade designation "TAUPE U28RW035K" from BASF Automotive
Refinish Technologies, Inc., Southfield, Mich.; [0062] "TP5": A
mild steel test panel coated with black primer, commercially
available under the trade designation "SIKKENS COLORBUILD BLACK"
from Akzo Nobel Coatings Inc., Norcross, Ga. Test Methods
[0063] The following test methods were used.
Off-Hand Abrasion Test.
[0064] An abrasive disc was secured to the appropriate size backup
pad according to the respective attachment system. The disc pad was
then attached to a dual action sander, commercially available as
model number "57015", from the Dynabrade Company, Clarence, N.Y.
Abrasion tests were run for up to 138 seconds, in various
intervals, over three adjacent sections of the test panel, at an
air pressure of up to 620.5 kPa (90 Psi) and a disc-to-panel angle
of 0-2.5 degrees.
Surface Finish
[0065] Surface finish (Rz) is the average individual roughness
depths of a measuring length, where an individual roughness depth
is the vertical distance between the highest point and the lowest
point. The surface finish of abraded test panels were measured
using a profilometer under the trade designation "PERTHOMETER MODEL
M4P-127527" from Mahr Corporation, Cincinnati, Ohio. Surface finish
values were measured at five points within each of the three
abraded sections of the test panel at the end of the third sanding
interval.
Cut Rate
[0066] Cut-rate refers to the ability of the abrasive article to
remove stock material or surface particles from the workpiece. The
cut rate is the amount of weight loss of the test panel during the
sanding operation. The test panel was weighed with an accurate
electronic balance before the sanding test began. Using the sample
test fixture the painted panel was sanded as described above. After
each sanding cycle the test panel was cleaned of accumulated swarf
by blowing with compressed air. The test panel was re-weighed to
establish the weight loss (cut) during each sanding interval. The
cumulative weight loss for each sanding interval was then recorded.
The tests were run in triplicate.
Stiction
[0067] Sanding a smooth abrasive coating may create what is known
in the industry as "stiction", whereby the abrasive coating may
stick to the workpiece surface, with unwanted results. It is
preferred to minimize stiction in fine finishing applications.
Examples 1-5 & Comparatives A-D
[0068] Samples of test panel TP1 were sanded according to the
method described above at a pressure of 620.5 kPa (90 Psi). Results
are listed in Table 1. TABLE-US-00001 TABLE 1 Sanding Total
Abrasive Back- Interval Cut Rate Cut Disc up Pad (seconds) (grams)
(grams) Example 1 AD2 BP1 30, 60, 90 Not 6.0 Measured Comparative A
AD1 BP1 30, 60, 90 Not 6.6 Measured Example 2 AD2 BP4 30, 60, 90
Not 7.2 Measured Comparative B AD1 BP4 30, 60, 90 Not 6.1 Measured
Example 3 AD4 BP1 30, 60, 90 1.79, 1.68, 5.0 1.51 Example 4 AD4 BP4
30, 60, 90 2.08, 1.92, 5.7 1.66 Comparative C AD3 BP1 30, 60, 90
1.84, 1.53, 4.8 1.46 Example 5 AD6 BP3 30, 60, 90 Not 5.2 Measured
Comparative D AD5 BP3 30, 60, 90 Not 3.6 Measured
Examples 6-8 & Comparatives E-G
[0069] Samples of test panel TP2 were sanded according to the
method described above at a pressure of 620.5 kPa (90 Psi). Results
are listed in Table 2. TABLE-US-00002 TABLE 2 Sanding Abrasive
Back- Interval Total Cut Disc up Pad (seconds) Improvement Example
6 AD6 BP3 30, 60, 90, 148% 120 Comparative E AD5 BP3 30, 60, 90,
100% 120 Example 7 AD6 BP3 30, 60, 90, 144% 120 Comparative F AD5
BP3 30, 60, 90, 100% 120 Example 8 AD8 BP3 30, 60, 90, 150% 120
Comparative G AD7 BP3 30, 60, 90, 100% 120
Example 9 & Comparative H
[0070] Samples of test panel TP1 were sanded according to the
method described above at a pressure of 620.5 kPa (90 Psi). Results
are listed in Table 3. TABLE-US-00003 TABLE 3 Sanding Total
Abrasive Back- Interval Cut Rate Cut Finish (microinches)/ Disc up
Pad (seconds) (grams) (grams) (micrometers) Example 9 AD9 BP3 30,
60, 90, 120 1.86, 1.42, 5.86 146/125 1.34, 1.24 (3.71/3.18) @30/120
s Comparative H AD7 BP3 30, 60, 90, 120 1.36, 0.95, 4.26 147/130
1.01, 0.95 (3.73/3.30) @30/120 s
Examples 10-11 & Comparative I
[0071] Samples of test panel TP1 were sanded according to the
method described above at a pressure of 620.5 kPa (90 Psi). Results
are listed in Table 4. TABLE-US-00004 TABLE 4 Sanding Total
Abrasive Back- Interval Cut Rate Cut Finish (microinches)/ Disc up
Pad (seconds) (grams) (grams) (micrometers) Example 10 AD11 BP3 30,
60, 90, 120 1.82, 1.31, 5.42 104/88 1.16, 1.13 (2.64/2.24) @30/120
s Example 11 AD12 BP3 30, 60, 90, 120 1.88, 1.40, 5.76 106/92 1.25,
1.23 (2.69/2.34) @30/120 s Comparative I AD10 BP3 30, 60, 90, 120
1.50, 1.10, 4.73 108/90 1.11, 1.02 (2.74/2.29) @30/120 s
Examples 12-14 & Comparatives J-L
[0072] Samples of test panel TP3 were sanding according to the
method described above at a pressure of 248.2 kPa (36 Psi). An
interface pad, commercially available under the trade designation
"HOOKIT II SOFT INTERFACE PAD" from 3M Company, was applied between
the abrasive disc and the back-up pad. Results are listed in Table
5. Three different lots of "260L P1000 HOOKIT II DISC" and "260L
P1000 HOOKIT II DUST-FREE DISC" were evaluated. TABLE-US-00005
TABLE 5 Sanding Abrasive Back- Interval Total Cut Finish
(microinches)/ Disc up Pad (seconds) (grams) (micrometers) Example
12 AD14, Lot 1 BP3 23, 46, 69, 0.30 76.8 92, 115, (1.95) 138
Comparative J AD13, Lot 1 BP3 23, 46, 69, 0.35 81.0 92, 115, (2.06)
138 Example 13 AD14, Lot 2 BP3 23, 46, 69, 0.35 89.1 92, 115,
(2.26) 138 Comparative K AD13, Lot 2 BP3 23, 46, 69, 0.33 87.3 92,
115, (2.22) 138 Example 14 AD14, Lot 3 BP3 23, 46, 69, 0.21 53.3
92, 115, (1.35) 138 Comparative L AD13, Lot 3 BP3 23, 46, 69, 0.25
56.4 92, 115, (1.43) 138
Examples 15-16 & Comparatives M-N
[0073] Samples of test panel TP2 were sanded according to the
method described above at a pressure of 275.8 kPa (40 Psi) using a
STIKIT disc pad. Results are listed in Table 6. TABLE-US-00006
TABLE 6 Abrasive Back- Sanding Interval Cut Rate Finish
(microinches)/ Disc up Pad (seconds) (grams) (micrometers) Example
15 AD16 BP1 23, 46, 69, 0.16, 0.27, 36.9 92, 115, 0.42, 0.54 (0.94)
138 Comparative M AD15 BP1 23, 46, 69, 0.19, 0.35, 33.5 92, 115,
0.51, 0.65 (0.85) 138 Example 16 AD16 BP4 23, 46, 69, 0.22, 0.44,
30.8 92, 115, 0.64, 0.85 (0.78) 138 Comparative N AD15 BP4 23, 46,
69, 0.21, 0.47, 31.5 92, 115, 0.69, 0.84 (0.80) 138
Example 17 & Comparative O
[0074] Samples of test panel TP4, moistened with a thin film of
water, were hand sanded using HOOKIT II discs attached to hand
HOOKIT II center water feed back up pad. Results are listed in
Table 7. TABLE-US-00007 TABLE 7 Sanding Total Abrasive Back-
Interval Cut Disc up Pad (seconds) (grams) Stiction Example 17 AD6
BP5 30 30.3 Low stiction Comparative O AD5 BP5 30 33.3 High
stiction
Example 18 & Comparative P
[0075] Samples of test panel TP5, were dry hand sanded using HOOKIT
II sheets attached to hard hand sanding block BP6, in a series of 4
intervals of 5 strokes (backward-forward) each. Cut performance and
stiction ratings, as an average of triplicate samples, are listed
in Table 8. TABLE-US-00008 TABLE 8 Abrasive Back- Cut Rate Disc up
Pad (grams) Stiction Example 18 AD20 BP6 0.47, 1.05, No stiction
1.34 Comparative P AD19 BP6 0.49, 1.02, High stiction 1.24
Examples 19-21 & Comparatives Q-S
[0076] Samples of test panel TP3 were sanded according to the
method described above at a pressure of 248.2 kPa (36 Psi). With
respect to Example 20 and Comparative R, an interface pad,
commercially available under the trade designation "HOOKIT SOFT
INTERFACE PAD" from 3M Company, was applied between the abrasive
disc and the back-up pad. With respect to Example 21 and
Comparative S, an interface pad, commercially available under the
trade designation "HOOKIT II SOFT INTERFACE PAD" from 3M Company,
was applied between the abrasive disc and the back-up pad. Results
are listed in Table 9. TABLE-US-00009 TABLE 9 Abrasive Back-
Sanding Interval Cut Rate Finish (microinches)/ Disc up Pad
(seconds) (grams) (micrometers) Example 19 AD16 BP1 30, 60, 0.40,
0.69, 84.8 120 1.02, (2.15) Comparative Q AD15 BP1 30, 60, 90,
0.33, 0.58, 78.9 120 0.97 (2.00) Example 20 AD18 BP2 30, 60, 90,
0.32, 0.67, 74.2 120 1.25 (1.89) Comparative R AD17 BP2 30, 60, 90,
0.31, 0.62, 73.4 120 1.12 (1.86) Example 21 AD14 BP3 30, 60, 90,
0.30, 0.62, 71.5 120 1.12 (1.82) Comparative S AD13 BP3 30, 60, 90,
0.31, 0.62, 73.7 120 1.10 (1.87)
Examples 22-24 & Comparatives T-V
[0077] Samples of test panel TP2 were sanded according to the
method described above at a pressure of 275.8 kPa (40 Psi). With
respect to Examples 23-24 and Comparatives U-V, interface pads, as
described previously, were applied between the abrasive disc and
the back up pad. Results are listed in Table 10. TABLE-US-00010
TABLE 10 Abrasive Back- Sanding Interval Cut Rate Finish
(microinches)/ Disc up Pad (seconds) (grams) (micrometers) Example
22 AD16 BP1 15, 30, 45, 0.25, 0.38, 40.1 60 0.62 (1.02) Comparative
T AD15 BP1 15, 30, 45, 0.16, 0.36, 48.0 60 0.69 (1.22) Example 23
AD18 BP2 15, 30, 45, 0.22, 0.46, 33.3 60 0.82 (0.85) Comparative U
AD17 BP2 15, 30, 45, 0.20, 0.36, 43.0 60 0.63 (1.09) Example 24
AD14 BP3 30 0.17, 0.38, 38.1 0.77 (0.97) Comparative V AD13 BP3 30
0.17, 0.40, 39.4 0.68 (1.00)
[0078] The abrasive disc, the means for the attachment of the
article to the back-up pad, the foam facing layer, the rigid
backing plate and threaded stud, as mentioned above in connection
with the discussion above, while useful and necessary from a
practical standpoint to the present invention, can be supplied by
known means and constructions in the field and thus should require
no further details than that provided herein to be understood by
one of ordinary skill in the art.
* * * * *