Note: Descriptions are shown in the official language in which they were submitted.
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
FLOCKED SUBSTRATES FOR USE AS SCOURING MATERIALS
The present invention relates to substrates that are suitable for consumer use
as scouring
materials for cleaning surfaces in various environments, including domestic,
industrial,
hospital and food industry environments.
Substrates that provide a scouring action are widely used for cleaning in the
domestic
environment, being most frequently employed for cleaning cooking utensils and
for
cleaning surfaces in kitchens and bathrooms. Scouring substrates that are
already known
for such uses include resin-bonded non-woven webs of the type described in US-
A-2 95~
593. Those webs may incorporate abrasive particles to enhance their abrasive
action.
Also known for scouring cooking utensils are pads that are formed from a
continuous tow
of crimped or undulated filaments, as described in US-A-4 991 362. Those pads
may also
incorporate abrasive particles to enhance their abrasive action.
It has also been proposed, in GB-A-1 539 477 and WO 02/06009, to use flocked
substrates
for domestic cleaning and to enhance the abrasive action of the substrates by
depositing
abrasive particles (in the form of beads of resin) on the free ends of the
flock fibres.
With the increasing use, in many environments, of surfaces that can be damaged
by
aggressive abrasive materials, there is a growing demand from consumers for
cleaning
substrates that have a softer abrasive action but which, nevertheless, are
able to remove
material such as dirt, grease, burnt-on food etc. quickly and thoroughly.
Consumers also
require cleaning substrates that are themselves easy to clean (for example,
simply by
rinsing after use) and retain no undesirable odours and no undesirable
residues (e.g. pieces
of food) that could subsequently contaminate other surfaces on which they
might be used.
It is an object of the present invention to enable those requirements to be
met.
The present invention is based on the surprising discovery that flocked
substrates in which
the flock fibres are short in comparison with those previously-proposed for
use in
domestic scouring substrates can function efficiently as scouring materials
without the
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
need to deposit any abrasive particles on the flock fibres. The absence of
abrasive particles
on the flock fibres reduces the likelihood that the substrate will damage a
surface that is
being cleaned.
The present invention accordingly provides, for use as a domestic scouring
material, a
flocked substrate wherein the flock comprises fibres that are arranged
substantially
perpendicular to the substrate and have a maximum length of 2.0 mm, the fibres
being
substantially free of abrasive particles.
Flocked substrates in which the flock fibres have a length of less than 2.0 mm
and are free
of abrasive particles have already been proposed for use as polishing pads in
certain
industrial processes (see WO 98/45112, FR-A-2 799 403 and EP-A-1 057 590 which
describe the use of flocked substrates for polishing items such as optical
glass and
semiconductor substrates). In those industrial processes, the polishing pads
are typically
used in combination with some form of polishing compound.
The present invention also provides a cleaning article comprising a flocked
substrate
laminated to a layer of foam, wherein the flock comprises fibres that are
arranged
substantially perpendicular to the surface of the substrate to which they are
secured and
have a maximum length of 2.0 mm, the fibres being substantially free of
abrasive particles.
The foam can be of any type known to be suitable for domestic cleaning,
including
cellulosic foams having a density in the range of from 75 to 125 Kg/m3 and
polyurethane
foams having a density in the range of from 18 to 30 Kg/m3. A cleaning article
of that
type, which may be in the form of a pad suitable for hand-held use, offers the
user two
different cleaning actions that are useful when cleaning surfaces, namely a
scouring action
provided by the flocked surface of the pad and a wiping action provided by the
opposed
foam surface of the pad.
The present invention fixrther provides cleaning article comprising a flocked
wipe, wherein
the flock comprises fibres that are arranged substantially perpendicular to
the surface of
the wipe to which they are secured and have a maximum length of 2.0 mm, the
fibres
being substantially free of abrasive particles.
2
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
The term "wipe" as used herein means liquid-absorbent web material that is
suitable for
use in either a dry or a damp condition to remove an unwanted substance from a
surface
by means of a wiping action. Wipes are often classified, in accordance with
their
durability, as "disposable" (meaning that they are intended to be discarded
immediately
after use), "semi-disposable" (meaning that it is possible to wash and re-use
them a limited
number of times), and "reusable" (meaning that they are intended to be washed
and re-
used). Known wipe materials generally have a basis weight in the range of from
15 to 300
gm/m2, although materials having a higher basis weight can be used, and
comprise knitted,
woven and non-woven materials. Wipe materials are often hydrophilic but can
also be
specifically constructed to absorb non-aqueous liquids, for example grease and
oil.
In a cleaning article in accordance with the invention, the flock should be
applied in such a
way that at least one area of a liquid absorbent surface of the wipe remains
exposed. A
cleaning article of that type also offers the user two different cleaning
actions that are
useful when cleaning surfaces, namely a scouring action provided by the
flocked areas) of
the wipe and a wiping action provided by the exposed liquid absorbent area(s).
Typically, both sides of a wipe provide the same wiping action. If, however, a
cleaning
article in accordance with the invention comprises a wipe in which the wiping
action is
provided by one side of the wipe only then the flock fibres should be applied
so that part at
least of the surface on that one side remains exposed.
By way of example, embodiments of the invention will now be described with
reference to
the accompanying drawings, in which:
Fig. 1 is a diagrammatic cross-section of a scouring substrate;
Fig. 2 is a plan view of a patterned scouring substrate;
Fig. 3 is a diagrammatic cross-section of a hand-held cleaning pad;
Fig. 4 is a perspective view of a hand-held cleaning pad;
Fig. 5 is a diagrammatic cross-section of another cleaning article; and
Figs. 6 and 7 are plan views of other cleaning articles.
3
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
The scouring substrate 1 shown in Fig. 1 is a flocked substrate in which the
flock
comprises fibres 3 arranged substantially perpendicular to the substrate
material 5, and
secured to the substrate material by a layer of adhesive 7.
Flocked substrates of the general type shown in Fig. 1, and processes for
manufacturing
them, axe well known. In the conventional processes, a layer of adhesive is
applied to the
substrate material and, while the adhesive is still tacky, flock fibres are
attracted to it
electrostatically so that they become embedded at one end in the adhesive and
stand up
generally perpendicular to the substrate material. The substrate is then
heated in an oven to
dry and cure the adhesive layer.
For the manufacture of the scouring substrate 1, any woven or non-woven
flexible
material suitable for domestic cleaning (i.e. able to withstand hot water and
cleaning
fluids) can be used for the substrate material 5. One suitable material is a
woven
polyester/cotton material comprising 65% polyester and 35% cotton, and having
a basis
weight of 105 g/m2.
Any fibres known to be suitable for flocking and also suitable for domestic
cleaning (i.e.
able to withstand hot water and cleaning fluids) can be used for the flock 3.
A particularly
suitable material is polyamide, especially in the form of nylon 6 or nylon
6.6, but
polypropylene or polyester fibres could also be used. The fibres, which may be
coloured
as required, preferably have a titre (mass per unit length) in the.range of
from 15 to ~0
dtex (more preferably in the range of from 22 to 50 dtex) and are cut to a
length no greater
than 2.0 mm. It has been found that a particularly effective scouring action
is achieved
using fibres having a length of 0.~ mm and a titre of 44 dtex, or a length of
0.4 mm and a
titre of 22 dtex.
The flock 3 may be applied evenly over the substrate material, in which case
it is
preferably applied in an amount of from 150 to 1~0 g/ma. Alternatively, the
flock 3 may
be applied so that it forms a pattern over the surface of the substrate
material 5: a process
by which that can be achieved is well-known and involves applying the adhesive
7 to the
surface in the required pattern, usually by some form of printing process,
with the result
4
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
that the flock fibres will be adhered to the substrate only in the areas to
which the adhesive
has been applied. Fig. 2, for example, shows a patteni that is achieved by
omitting the
adhesive 7 from regularly-spaced rectangular patches 11 of the substrate
material 5. In this
case, the flock fibres 3 will adhere to the substrate material 5 everywhere
except in those
patches, where the substrate will remain exposed. The size of the patches 11
can be altered
to change the area of the substrate material 5 that is not covered by the
flock 3, and the
shape of the patches 11 can also be changed.
The adhesive selected to bind the flock 3 to the substrate material 5 should
also be suitable
for domestic cleaning (in particular, it should be able to withstand hot water
and cleaning
fluids), and should not adversely affect the flexibility of the substrate
material. Suitable
adhesives are acrylic adhesives and PVC (polyvinylchloride) resins, and are
applied in an
amount (for example, about 90 to 140 g/m2) that will yield a very thin layer
on the
substrate material.
It has been found that a flocked substrate constructed as described above with
reference to
Fig. 1 will provide an effective scouring action in the domestic environment,
sufficient not
only to clean kitchen and bathroom surfaces but also to remove burnt-on food
from
cooking utensils using normal liquid detergents, despite the absence of any
abrasive
particles on the flock fibres 3. The scouring action has been found to be
comparable to,
and in some cases better than, that of non-woven, non-scratch, domestic
scouring materials
that are currently commercially available including some that contain plastic
(or other
soft) abrasive particles. On the other hand, the absence of abrasive particles
from the
flocked substrate substantially eliminates the risk of any damage being done
to the surface
that is being cleaned. The flocked substrate has been found not to trap
residues of material
removed from the surface that is being cleaned, so that any residues remaining
on the
substrate after use are easily removed by simply rinsing the substrate in
water. If desired,
the substrate can be washed in hot water and detergent, and then re-used.
The appearance of the flocked substrate can be varied by using a substrate
material that is
coloured, or carnes a printed design, and applying the flock 3 in such a way
that the colour
or printed design remains apparent.
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
In a preferred embodiment of the invention, a flocked substrate 1 as described
above with
reference to Figs. 1 and 2 is laminated to a layer of foam 9 as shown in Fig.
3 The
laminate may then be cut into pads of a suitable size for domestic cleaning,
in particular
for hand-held use. The foam 9 can be of any type known to be suitable for
domestic
cleaning, including cellulosic foams having a density in the range of from 75
to 125 Kg/m3
and polyurethane foams having a density in the range of from 18 to 30 Kg/m3.
The foam can be of any suitable thickness but it has been found that
thicknesses in the
range of from 0.5 to 5.0 cm are particularly useful for domestic cleaning.
When a thinner
layer of foam is used, the laminate can be cut into pads having a larger
surface area (e.g.
having dimensions of up to 20 cm by 20 cm). A thicker layer of foam may be
more
suitable for pads having a smaller surface area (e.g. dimensions of about 7 cm
by 9 cm).
By way of example, a cleaning pad 13 that comprises a flocked substrate 15
laminated to a
layer of foam 17 is shown in Fig. 4. In this case, the flock is applied on the
substrate to
form the pattern illustrated in Fig. 2: that is not essential, however, and
the flock could be
applied to form other patterns, or be applied continuously over the substrate.
Fig. 5 shows a cleaning article 21 that also comprises a flocked substrate in
which the
flock comprises fibres 23 arranged substantially perpendicular to the
substrate 25, and
secured to the substrate by a layer of adhesive 27. In this case, however, the
substrate 25
comprises a wipe suitable for consumer use for cleaning surfaces. The wipe 25
may be
"disposable" (meaning that it intended to be discarded immediately after use),
"semi-
disposable" (meaning that it is possible to wash and re-use it a limited
number of times),
or "reusable" (meaning that it is intended to be washed and re-used). Known
wipe
materials generally have a basis weight in the range of from 15 to 300 gm/m2,
although
materials having a higher basis weight could be used. Woven and knitted
materials are
suitable, as are non-woven materials including dry-laid, wet-laid and spun-
bonded
materials which may, as appropriate, be thermally-bonded, resin-bonded,
ultrasonically-
bonded, needle-punched, hydro-entangled etc.
6
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
Materials suitable for disposable wipes include spun-bond and spun-lace non-
woven
materials having a basis weight in the range of from 15 to 75 g/ma and formed,
for
example, from PET, rayon, viscose, wood pulp, polypropylene, natural fibres,
polyamide
or mixtures thereof. Examples of disposable wipe materials are available under
the trade
names: "Sontara" from DuPont; and "TenoLace" from Tenotex of Terno d'Isola,
Italy.
Materials suitable for semi-disposable wipes include spun-lace non-woven
materials
having a basis weight in the range of from 75 to 250 g/ma and formed, for
example, from
fibres or microfibres of polyester, polyamide, viscose. Examples of semi-
disposable wipe
materials are available under the trade names "Scotch-BriteTM Dusting Cloth"
from 3M
Company of St. Paul, Minnesota, USA; and "Sontara" from DuPont.
Materials suitable for reusable wipes include knitted, woven, thermo-bonded,
latex-coated,
and chamois-type materials having a basis weight in the range of from 100 to
300 g/m2 and
formed, for example, from fibres or microfibres of PET, rayon, viscose,
polypropylene,
natural fibres, polyamide or mixtures thereof. An example of a reusable wipe
is available
under the trade name "Ideal" from Lever of Madrid, Spain.
Wipes are often hydrophilic but can also be specifically constructed to absorb
non-
aqueous liquids. Microfibre wipes, for example, are intended to remove grease
from
surfaces.
Typically, both sides of the wipe 25 will provide the same wiping action. If,
however, only
one side of the wipe 25 provides a wiping action then the flock fibres 23 are
applied to the
wipe in such a way that a sufficient area of that one side of the wipe remains
exposed and
can be used to provide a wiping action. For example, in such a case the flock
fibres 23
could be applied only to the other (non-wiping) side of the wipe 25.
The description above of the flock 3 of Figs. 1 to 3 applies also to the flock
23 of cleaning
article 21. The flock 23 can likewise be applied either evenly over the
surface of the wipe
25, in which case it is preferably applied in an amount of from 150 to 180
g/m2, or more
preferably so that it forms a pattern over the surface of the wipe 25 in the
manner
7
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
described above. In the latter case, use of a screen coating process for
applying the
adhesive 27 in a desired pattern on the surface of the wipe material is
preferred, because it
enables a very thin layer of a high-viscosity adhesive to be applied: that, in
turn, enables
the liquid-absorbent properties of the non-coated regions of the surface and
the liquid-
absorbent properties of the other surface of the wipe (as appropriate) to be
retained.
The flock 23 may be applied to the surface of the wipe 25 in the pattern
illustrated in Fig.
2 or, by way of example, in the alternative patterns illustrated in Figs. 6
and 7. Other
patterns could be used, including non-ordered patterns if desired.
Fig. 6 shows a pattern that is achieved by printing adhesive 27 onto the wipe
25 as two
perpendicular sets of parallel lines; and Fig. 7 shows a pattern that is
achieved by printing
adhesive 27 onto the wipe 25 as one set of parallel lines. When the surface of
the wipe 25
to which the flock is applied is liquid-absorbent, the flock is preferably
applied in such a
way that the liquid-absorbent properties are retained in the un-flocked areas.
The flock is
also preferably applied in such a way that any liquid-absorbent properties of
the other
surface of the wipe are unaffected. For some applications, it may be desirable
to apply the
flock only in one selected area of the wipe 25, for example, in one corner.
The adhesive selected to bind the flock 23 to the wipe 25 should also be
suitable for use in
the conditions for which the wipe is intended (for example, able to withstand
hot water
and cleaning fluids). Preferably, it should not adversely affect either the
flexibility of the
wipe or, as already mentioned, the liquid-absorbency of the uncoated parts of
the wipe
surface. Suitable adhesives and coating weights are as described above for the
adhesive 7
of Fig. 1.
If desired, a further coating of adhesive can be applied on top of the first
layer, after the
flock has been applied and the first layer of adhesive has cured. This
additional process
step is already known in the textile art for increasing the durability of
flocked materials.
It has been found that a flocked wipe constructed as described above with
reference to Fig.
5 will, through use of the flocked surface, provide an effective scouring
action sufficient
8
CA 02497438 2005-03-02
WO 2004/021855 PCT/US2003/027223
not only to clean work surfaces but also to remove burnt-on food from cooking
utensils
using normal liquid detergents, despite the absence of any abrasive particles
on the flock
fibres 23. The scouring action has been found to be comparable to, and in some
cases
better than, that of non-woven, non-scratch, domestic scouring materials that
are currently
commercially available including some that contain plastic (or other soft)
abrasive
particles. On the other hand, the absence of abrasive particles from the flock
fibres 23
substantially eliminates the risk of any damage being done to the surface that
is being
cleaned. At the same time, the unflocked surface or surface areas of the wipe
are available
to provide the normal wiping action for which the wipe 25 is intended. The
flocked
surface or surface areas of the wipe 25 have been found not to trap residues
of material
removed from a surface that is being cleaned, so that any residues remaining
on the wipe
after use are easily removed by simply rinsing the wipe in water.
The wipe 25 will typically be of a size suitable for hand use but could, for
example, be of a
larger size suitable for use on a mop head for cleaning floors.
9
