U.S. patent application number 12/573236 was filed with the patent office on 2010-04-08 for scouring material comprising natural fibres.
Invention is credited to Jean-Marie Coant, Maria de los Angeles Alcazar, Cristobal Martin-Bernia, Carmen Martin Rivera, Jeremie PEYRAS-CARRATTE.
Application Number | 20100087117 12/573236 |
Document ID | / |
Family ID | 40042277 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100087117 |
Kind Code |
A1 |
PEYRAS-CARRATTE; Jeremie ;
et al. |
April 8, 2010 |
SCOURING MATERIAL COMPRISING NATURAL FIBRES
Abstract
A scouring material comprises a three-dimensional non-woven web
(3) of entangled fibres (5) bonded to one another at mutual contact
points (7). The fibres comprise natural vegetable fibres in an
amount of at least 50% by weight, and crimped synthetic fibres in
an amount of at least 5% by weight. The fibres, throughout the web,
have a substantially continuous coating of binder resin; and the
web of bonded fibres has a maximum density of 60 kg/m.sup.3. A
method of making the scouring material comprises the steps of:
forming a three-dimensional non-woven web of entangled fibres;
roll-coating the web with a binder resin; and curing the binder
resin to form the scouring material.
Inventors: |
PEYRAS-CARRATTE; Jeremie;
(Chambly, FR) ; Coant; Jean-Marie; (Saint-Denis,
FR) ; Martin Rivera; Carmen; (Madrid, ES) ;
Martin-Bernia; Cristobal; (Madrid, ES) ; de los
Angeles Alcazar; Maria; (Madrid, ES) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
40042277 |
Appl. No.: |
12/573236 |
Filed: |
October 5, 2009 |
Current U.S.
Class: |
442/356 ;
264/128 |
Current CPC
Class: |
B24D 11/005 20130101;
D04H 1/55 20130101; D04H 1/4266 20130101; D04H 1/64 20130101; D04H
1/587 20130101; D04H 1/549 20130101; D04H 1/4291 20130101; Y10T
442/632 20150401; A47L 13/16 20130101; D04H 1/425 20130101; D04H
1/541 20130101; D04H 1/435 20130101; D04H 1/4334 20130101; D04H
1/66 20130101; D04H 1/04 20130101 |
Class at
Publication: |
442/356 ;
264/128 |
International
Class: |
D04H 3/12 20060101
D04H003/12; D04H 1/64 20060101 D04H001/64 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 6, 2008 |
GB |
0818186.9 |
Claims
1. A scouring material comprising a three-dimensional non-woven web
of entangled fibres bonded to one another at mutual contact points,
wherein: (i) the fibres comprise natural vegetable fibres in an
amount of at least 50% by weight, and crimped synthetic fibres in
an amount of at least 5% by weight; (ii) the fibres, throughout the
web, have a substantially continuous coating of binder resin; and
(iii) the web of bonded fibres has a maximum density of 60
kg/m.sup.3.
2. The scouring material of claim 1, wherein the natural vegetable
fibres comprise fibres from the hearts of Agave tequilana; fibres
from the leaves of Agave sisalana; or fibres from the tissues
surrounding the seeds of Cocos nucifera; or mixtures thereof.
3. The scouring material of claim 1, wherein the amount of natural
vegetable fibres in the non-woven web is greater than 50% by
weight.
4. The scouring material of claim 3, wherein the amount of natural
vegetable fibres in the non-woven web is at least 60% by
weight.
5. The scouring material of claim 2, wherein the natural vegetable
fibres also comprise finer fibres.
6. The scouring material of claim 1, wherein the crimped synthetic
fibres comprise polyamide fibres; polyester fibres; polypropylene
fibres; or mixtures thereof.
7. The scouring material of claim 1, wherein the crimped fibres
have a denier of at least 2 dtex, preferably at least 15 dtex.
8. The scouring material of claim 1, wherein the binder resin is a
water-based resin, for example a latex resin or an acrylic
resin.
9. The scouring material of claim 1, wherein at least some of the
fibres are bonded to one another at mutual contact points by a
pre-bond resin.
10. The scouring material of claim 9, wherein the pre-bond resin is
a polyester resin.
11. The scouring material of claim 1, further comprising abrasive
particles adhered to the web by a make-coat resin.
12. The scouring material of claim 11, wherein the abrasive
particles comprise aluminium oxide particles or poly(vinyl
chloride) particles.
13. The scouring material of claim 11, wherein the make-coat resin
is a water-based resin, for example a latex resin or an acrylic
resin.
14. A method of making a scouring material of claim 1, the method
comprising the steps of: (a) forming a three-dimensional non-woven
web of entangled fibres; (b) roll-coating the web with a binder
resin; and (c) curing the binder resin to form the scouring
material.
15. The method of claim 14, wherein the fibres include
heat-sensitive fibres and the method comprises the further step,
between steps (a) and (b), of applying heat to the web to form a
pre-bonded web in which some at least of the fibres are bonded to
one another at mutual contact points by a pre-bond resin provided
by the heat-sensitive fibres.
16. The method of claim 15, wherein the heat-sensitive fibres are
polyester fibres.
17. The method of claim 15, wherein the heat-sensitive fibres also
provide at least some of the crimped synthetic fibres in the
scouring material.
18. The method of claim 14, comprising the further step, after step
(c), of spraying the web with a slurry of abrasive particles in a
make-coat resin.
Description
[0001] This application claims priority from United Kingdom
Application No. 0818186.9, filed Oct. 6, 2008.
[0002] The present disclosure relates to non-woven fibrous scouring
materials suitable for use for cleaning surfaces.
BACKGROUND
[0003] Scouring materials are produced in many forms, one being as
a web of non-woven fibrous material (for example material of the
type described in U.S. Pat. No. 2,958,593 of Hoover et al).
Following manufacture, the web of scouring material may be divided
into individual pieces of a size suitable for its intended use.
[0004] Examples of scouring pads comprising non-woven fibrous
materials are described in U.S. Pat. No. 2,327,199 (Loeffler), U.S.
Pat. No. 2,375,585 (Rimer), and U.S. Pat. No. 3,175,331 (Klein).
Non-woven fibrous hand pads for domestic use and for more general
abrasive applications are available, under the trademark
"Scotch-Brite", from 3M Company of St. Paul, Minn., USA, and
non-woven fibrous hand pads that provide a very mild scouring
action for skin cleansing are available, under the trademark
"Buf-puf", also from 3M Company. Non-woven fibrous scouring
materials are also used outside the domestic environment, for
example in floor pads such as those available, also under the
trademark "Scotch-Brite", from 3M Company.
[0005] A non-woven fibrous scouring material is preferably a
comparatively open material (i.e. it has a comparatively high void
volume) so that it can retain debris removed from the surface that
is being cleaned and thereby provide an effective cleaning action.
Such a material can also be cleaned very easily by rinsing in water
or another suitable liquid, so that it can be re-used.
[0006] Known processes for manufacturing non-woven fibrous
materials having a comparatively high void volume involve forming
an open, three-dimensional non-woven web of synthetic fibres,
applying a liquid binder resin to the web, and then curing the
binder resin to bond the fibres together. A preferred method of
applying the binder resin is roll coating, which coats the fibres
with the resin substantially continuously throughout the web. For
use as a scouring material, this bonded web of fibres typically has
a maximum density of 60 kg/m.sup.3. The characteristics of the
bonded web may be such that it can be used without further
treatment as a scouring material. Alternatively, abrasive particles
can be adhered to the bonded web to enhance the abrasive
characteristics of the web.
[0007] Scouring products formed from materials produced in this way
are popular with consumers and are widely used in the domestic
environment and elsewhere. However, in this area as in many others,
environmental concerns are leading to an increasing demand from
consumers for products that are based on natural materials,
especially materials derived from plants (including trees and
bushes). In the case of fibres, there is a growing interest in
fibres derived directly from plants (i.e. non-regenerated vegetable
fibres, hereinafter referred to as natural vegetable fibres).
[0008] Scouring materials formed solely from natural vegetable
fibres are known and include, for example, traditional scourers for
domestic use formed from the fibrous parts of gourds or palm
leaves. Such traditional scourers have the disadvantage that they
cannot be mass-produced to a uniform standard.
[0009] The use of a substantial amount of natural vegetable fibres
in place of synthetic fibres in a conventional manufacturing
process of the type described above has not been seen as an option
for mass-producing non-woven fibrous scouring materials having a
comparatively high void volume because of the risk that the
vegetable fibres will be crushed when the liquid binder resin is
applied, resulting in a bonded web that has a reduced void volume
and is too compact to function effectively as a scouring material.
The risk of the fibres being crushed is considered to be
particularly high if the binder resin is applied by roll coating.
With that mind, EP-A-1 618 239 (3M Innovative Properties Company)
describes a method of making a scouring material comprising the
steps of: forming a three-dimensional non-woven web of natural
fibres contacted with dry particulate material that includes
fusible binder particles; exposing the web to conditions that cause
the binder particles to form a flowable liquid binder; and then
solidifying the liquid binder to form bonds between the fibres of
the web and thereby provide a bonded web. Abrasive particles are
then adhered to the pre-bonded web by at least a make-coat
resin.
[0010] Although the method described in EP-A-1 618 239 is
effective, it requires the use of apparatus that is less widely
available than that used to carry out the conventional type of
manufacturing process referred to above. It would be advantageous
to be able to continue to use the conventional type of process to
produce non-woven fibrous scouring materials comprising a
substantial amount of natural vegetable fibres, and the present
disclosure is based on the surprising discovery that this can be
achieved through an appropriate selection of the fibres
employed.
SUMMARY
[0011] The present disclosure provides a scouring material
comprising a three-dimensional non-woven web of entangled fibres
bonded to one another at mutual contact points, wherein:
(i) the fibres comprise natural vegetable fibres in an amount of at
least 50% by weight, and crimped synthetic fibres in an amount of
at least 5% by weight; (ii) the fibres, throughout the web, have a
substantially continuous coating of binder resin; and (iii) the web
of bonded fibres has a maximum density of 60 kg/m.sup.3.
[0012] In the case of hand pads for domestic use, the scouring
material typically has a maximum density of 55 kg/m.sup.3, more
especially a density in the range of from 25 to 45 kg/m.sup.3.
[0013] The inclusion of crimped synthetic fibres with the natural
vegetable fibres has been found to facilitate the production of a
scouring material using the conventional type of manufacturing
process described above, especially one in which a binder resin is
applied to a web of fibres by roll coating.
[0014] With a view to providing scouring materials in which the
amount of natural vegetable fibres in the non-woven web is greater
than 50% by weight, it has been found advantageous to select
natural fibres that comprise fibres from the hearts of Agave
tequilana; fibres from the leaves of Agave sisalana; or fibres from
the tissues surrounding the seeds of Cocos nucifera; or mixtures
thereof. The natural vegetable fibres may also comprise finer
fibres, for example hemp fibres.
[0015] A method of making a scouring material in accordance with
the disclosure may comprise the steps of:
(a) forming a three-dimensional non-woven web of entangled fibres;
(b) roll-coating the web with a binder resin; and (c) curing the
binder resin to form the scouring material.
[0016] As described above, such a method offers the advantage that
it can be carried out using apparatus that is already known and
widely available. In some cases, the non-woven web of entangled
fibres includes heat-sensitive fibres and the method comprises the
further step, between steps (a) and (b), of applying heat to the
web to form a pre-bonded web in which some at least of the fibres
are bonded to one another at mutual contact points by a pre-bond
resin provided by the heat-sensitive fibres. The heat-sensitive
fibres, when present, may contribute at least some of the crimped
synthetic fibres in the web of bonded fibres. For example, if the
heat-sensitive fibres are bi-component fibres having a sheath/core
structure, the cores of the heat-sensitive fibres may contribute at
least some of the crimped synthetic fibres in the web of bonded
fibres.
[0017] As used herein, the term "natural vegetable fibres" means
fibres derived directly from plants (including trees and bushes);
the term "synthetic fibres" means fibres produced from synthetic
polymers, typically by extrusion; and the term "roll-coating" means
a process in which a nonwoven fibrous web is passed between rollers
that apply resin to the web with sufficient pressure to ensure that
the fibres, throughout the web, receive a substantially continuous
coating of the resin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] By way of example only, scouring materials in accordance
with the disclosure and methods of making those materials will now
be described with reference to the accompanying drawings, in
which
[0019] FIG. 1 shows a scouring pad comprising scouring material in
accordance with the disclosure;
[0020] FIG. 2 illustrates diagrammatically, and on an enlarged
scale, the structure of the scouring pad of FIG. 1;
[0021] FIG. 3 is a diagrammatic illustration of apparatus for
making scouring materials in accordance with the disclosure;
and
[0022] FIG. 4 is a diagrammatic illustration of another form of
apparatus for making scouring materials in accordance with the
disclosure.
DETAILED DESCRIPTION
[0023] FIG. 1 shows a generally-rectangular scouring pad 1 intended
for hand use, and FIG. 2 illustrates the structure of the pad
material in greater detail. The pad 1 comprises a three-dimensional
non-woven web 3 of entangled fibres 5, bonded to one another at
mutual contact points 7. The fibres 5, described in greater detail
below, comprise at least 5% by weight of crimped synthetic fibres
and at least 50% by weight of natural vegetable fibres. Throughout
the web 3, the fibres 5 have a substantially continuous coating of
binder resin (not visible in the drawing). FIG. 2 also shows
optional abrasive particles 9 adhered to the fibres. The web of
fibres 5, including the binder resin but without the abrasive
particles 9 has a maximum density of 60 kg/m.sup.3 (more
preferably, in the case of hand pads for domestic use, a density in
the range of from 25 to 45 kg/m.sup.3).
[0024] If desired, a scouring pad as shown in FIG. 1 can be
laminated to another type of material, for example a sponge
material. Advantageously, that other material is a natural material
(for example, a cellulosic sponge) or has a comparatively high
content of natural material.
[0025] A process for making the web 3 and the scouring pad 1 will
now be described with reference to FIG. 3, which illustrates
apparatus for carrying out the process.
[0026] The apparatus illustrated in FIG. 3 comprises web-forming
equipment 10 to which a selected mix of fibres 11 is supplied to be
formed into a dry-laid, open, lofty three-dimensional web 12. A
preferred type of web is an air-laid web as described in U.S. Pat.
No. 2,958,593, in which case the web-forming equipment 10 may be a
commercially-available "Rando-Webber" device available, for
example, from the Rando Machine Co. of Macedon, N.Y., USA.
Alternatively, the web-forming equipment 10 may be of the type
described in WO 05/044529 (Form-Fibre Denmark APS), or of the type
available from DOA of Linz, Austria.
[0027] The fibre mix 11 comprises at least 50% by weight natural
vegetable fibres and at least 5% by weight crimped synthetic
fibres. Examples of suitable fibre mixes will be described in
greater detail below. For the production of a web of open scouring
material, the web-forming equipment 10 is preferably operated to
produce a dry-laid web 12 having a minimum thickness of about 5 mm
and a maximum basis weight of about 500 g/m.sup.2. If the web is
intended for conversion into hand pads, a maximum basis weight of
about 300 g/m.sup.2 may be preferred. Other web thicknesses and
basis weights may, however, be appropriate depending on the
required nature of the scouring material that is being
produced.
[0028] Downstream of the web-forming equipment 10 is a conventional
roll-coating station 13, where the web 12 passes through the nip
between rollers 14 that apply a binder resin 15 from a tank 16 to
the web at a metered rate. The pressure exerted by the rollers 14
on the web is sufficient to ensure that the binder resin penetrates
the entire thickness of the web and coats the fibres throughout.
The web then passes through an oven 17 which is operated at a
temperature sufficient to cure the binder resin 15 whereby, when
the web has emerged from the oven and cooled, the fibres 11 are
bonded together at their points of contact and, throughout the web
(now indicated by the reference 12'), have a substantially
continuous coating of the binder resin.
[0029] Through a suitable choice of the materials and the process
conditions employed, the characteristics of the web 12' (e.g. its
tensile strength, flexibility, durability) can be adapted to the
intended use of the web.
[0030] Depending on the nature of the fibres 11, the bonded web 12'
may be suitable without further treatment for use as a scouring
material for domestic or cosmetic cleaning. If so, it can be cut
into pads of a suitable size for the intended use, typically pads
of a suitable shape and size for hand-held use. If required,
however, the abrasive properties of the web 1 can be enhanced by
applying a make-coat resin with optional abrasive particles 9 to
the web as shown in FIG. 2. That can be achieved by passing the web
12' through the additional apparatus illustrated in FIG. 3, which
comprises successive spray booths 18, 19, each having an associated
oven 20, 21. As the web passes through the first spray booth 18,
one surface of the web is sprayed with a liquid make-coat resin (or
a slurry 22 of abrasive particles mixed with the make-coat resin)
that is subsequently cured by passing the web through the oven 20.
The web then passes through the second spray booth 19, in which
other surface of the web is sprayed with the same liquid make-coat
resin, or abrasive-resin slurry, which is then cured by passing the
web through the oven 21. The resulting abrasive web 12'' may then
be cut into pads of a suitable shape and size as already described
above. If the surfaces of the web are required to have different
scouring properties, two different make-coat resins or
abrasive-resin slurries can be used in the spray booths 18, 19.
Alternatively, a make-coat resin or abrasive-resin slurry may be
applied to one surface only of the web.
[0031] In a modified version of the apparatus, the second spray
booth 19 and the associated oven 21 are omitted and the web is
turned over after it has left the first oven 20 and is conveyed a
second time through the first spray booth 18 so that the other side
of the web can be sprayed. The web then passes for a second time
through the oven 20. The web may then be cut into pads of a
suitable shape and size as already described above.
[0032] FIG. 4 illustrates a modified form of the apparatus shown in
FIG. 3, suitable for use when it is desired to consolidate the web
12 emerging from the web-forming equipment 10 before it passes to
the roll-coating station 13. The consolidation may be required, for
example, if the web 12 cannot be passed directly to the
roll-coating station 13 from the web-forming equipment 10 and,
consequently, is subjected to additional handling. The apparatus of
FIG. 4 differs from that shown in FIG. 3 by the inclusion of an
oven 25 between the web-forming equipment 10 and the roll-coating
station 13. Use of the apparatus of FIG. 4 requires that the fibre
mix 11 supplied to the web-forming equipment includes
heat-sensitive fibres that will melt when the web 12 passes through
the oven 25, forming bonds between other fibres in the web
sufficient to enable the web to withstand any handling that it
might receive during its passage to the roll-coating station 13.
Thereafter, the process carried out using the apparatus of FIG. 4
is as described above with reference to FIG. 3.
[0033] When appropriate, other methods could be used in the process
of FIG. 4 for consolidating the web 12 emerging from the
web-forming equipment 10.
[0034] Scouring materials can be produced as described above in a
variety of thicknesses and basis weights, and can be cut into other
shapes, depending on their intended use. Thicker webs, for example,
may be cut into discs for use as floor pads.
[0035] The materials employed when using the apparatus of FIG. 3 or
FIG. 4 to make scouring materials in accordance with the disclosure
will now be described.
The Fibres
[0036] Any suitable fibres can be used in the apparatus of FIGS. 3
and 4, provided they enable a non-woven fibrous material suitable
for use as a scouring material to be produced.
[0037] With regard to the crimped synthetic fibres, and without
wishing to be bound by theory, it is believed that they contribute
to the resilience of the web 12 that is produced in the web-forming
equipment 10 of the apparatus of FIGS. 3 and 4, and thus influence
the ability of the web to be roll-coated in the station 13 without
being crushed to such an extent that its open nature is destroyed.
The crimped synthetic fibres should comprise at least 5% by weight
of the total fibre content of the final scouring material, the
actual amount being determined having regard to the nature of the
other fibres in the fibre mix 11 (particularly the natural
vegetable fibres) and the required characteristics of the final
scouring material. Crimped synthetic fibres suitable for use in the
fibre mix 11 include crimped nylon fibres and crimped polyester
fibres. Mixtures of different crimped synthetic fibres may also be
used.
[0038] Generally, it has been observed that the ability of the web
12 to resist being crushed in the roll-coating station 13 tends to
increase with the amount of synthetic fibre present in the web;
with the linear density of the crimped synthetic fibres; and with
the degree of crimp in the crimped synthetic fibres. The synthetic
fibres should have a length in the range normally used for
non-woven fibrous webs (typically between 40 and 60 cm), it being
known that very long fibres may get trapped in the web-forming
equipment 10 and that short fibres tend to reduce the cohesion of
the web.
[0039] In examples of scouring materials in accordance with the
disclosure, at least some of the crimped synthetic fibres have a
linear density of at least 15 dtex. However, the use of crimped
synthetic fibres having a linear density of less than 15 dtex is
possible, depending on the nature of the other fibres in the fibre
mix 11. Typically, the degree of crimp in the fibres will be in the
range of from about 2 to about 10 crimps per cm.
[0040] As regards the natural vegetable fibres present in the fibre
mix 11, it has been found that the nature of those fibres also has
an influence on the resilience of the web 12 produced in the
web-forming equipment 10, and thus on the ability of the web to be
roll-coated in the station 13 without being crushed to such an
extent that its open nature is destroyed. Some natural vegetable
fibres can provide comparatively-resilient open webs even when
combined with only comparatively-small amounts of crimped synthetic
fibres, whereas other natural vegetable fibres may need to be
combined with larger amounts of crimped synthetic fibres to enable
open webs with the required resilience to be produced. When
selecting the natural vegetable fibres, account should be taken of
the wide variation in length and linear density that occurs even
among fibres derived from the same plants.
[0041] Examples of natural vegetable fibres capable of providing
comparatively-resilient open webs even when combined with only
comparatively-small amounts of crimped synthetic fibres
include:
(i) fibres from the hearts (also known as the pine cones) of Agave
tequilana (hereinafter referred to as agave fibres, available in
various grades depending on the washing and-or drying treatment to
which the fibres have been subjected); (ii) fibres from the leaves
of Agave sisalana (hereinafter referred to as sisal fibres); and
(iii) fibres from the tissues surrounding the seed of Cocos
nucifera (hereinafter referred to as coco fibres and also known as
coir).
[0042] Mixtures of those fibres may be used and, in some case, the
fibres may be mixed with finer natural vegetable fibres, for
example, hemp fibres.
[0043] When heat-sensitive fibres are included in the fibre mix 11
as described above with reference to FIG. 4, they should be
selected to ensure that they melt and bond to the other fibres in
the web at a temperature below that at which those other fibres
would be degraded or melted. Heat-sensitive fibres may be either
mono-component or multi-component fibres.
[0044] A multi-component fibre is a synthetic fibre having at least
a first portion and a second portion, where the first portion has a
melting point lower than the second portion. A variety of different
types and configurations of multi-component fibre exist. One type
of multi-component fibre is a bi-component fibre, examples of which
are described in U.S. Pat. No. 5,082,720 of Minnesota Mining and
Manufacturing Company. One form of bi-component fibre has a
sheath/core structure, where the sheath that surrounds the core has
the lower melting point. Another form of multi-component fibre has
a layered structure, where one layer has a lower melting point than
another layer.
[0045] During heating, the first (lower melting point) portion of a
multi-component fibre will melt, while the second (higher melting
point) portion remains intact. During melting, the first portion
tends to collect at junction points where fibres contact one
another. Then, upon cooling, the material of the first portion will
re-solidify to secure the fibres together.
[0046] The first (lower melting point) portion of a multi-component
fibre may be comprised of such materials as copolyester or
polyethylene; and the second portion may be comprised of such
materials as polypropylene or polyester.
[0047] When multi-component fibres are included in the fibre mix,
the higher melting point portion may contribute to the content of
crimped synthetic fibre in the scouring material produced (see
above).
The Binder Resin
[0048] Any resin known to be suitable for roll-coating and for use
in the manufacture of scouring materials can be used in the
roll-coating stations 13 of the apparatus shown in FIGS. 3 and 4
although, for environmental reasons, water-based resins are
preferred. The resin should be selected to provide the scouring
material with sufficient flexibility and strength for its intended
use, and with the appropriate degree of water and heat resistance.
Suitable resins include phenolic resins, polyurethane resins,
polyureas, styrene-butadiene rubbers, nitrile rubbers, epoxies,
acrylics, and polyisoprene. The resin is preferably water soluble.
Examples of water soluble resins include modified styrene-butadiene
rubbers, polyethylene glycol, polyvinylpyrrolidones, polylactic
acid (PLA), polyvinylpyrrolidone/vinyl acetate copolymers,
polyvinyl alcohols, carboxymethyl celluloses, hydroxypropyl
cellulose starches, polyethylene oxides, polyacrylamides,
polyacrylic acids, cellulose ether polymers, polyethyl oxazolines,
esters of polyethylene oxide, esters of polyethylene oxide and
polypropylene oxide copolymers, urethanes of polyethylene oxide,
and urethanes of polyethylene oxide and polypropylene oxide
copolymers.
[0049] The coating weight of the binder resin may be in the range
of from 50 to 300 g/m.sup.2 (dry), more specifically 100 to 200
g/m.sup.2 (dry).
The Optional Make-Coat Resin or Abrasive-Resin Slurry
[0050] The slurry applied in the spray booths 18, 19, when used,
typically comprises abrasive particles in an amount in the range of
from 30 to 55% by weight.
[0051] The abrasive particles used in the slurry can be of any type
known to be suitable for scouring materials, taking into account
the nature of the surfaces to be cleaned and the abrasive action
that the scouring material is required to produce. Suitable
abrasive materials include inorganic materials, for example
aluminium oxide (including ceramic aluminium oxide, heat-treated
aluminium oxide, and white-fused aluminium oxide), silicon carbide,
tungsten carbide, alumina zirconia, diamond, ceria, cubic boron
nitride, silicon nitride, garnet, and combinations thereof.
Suitable abrasive materials also include softer, less aggressive
materials such as polymeric particles and crushed natural materials
(for example, crushed nut shells). Suitable polymeric materials for
the abrasive particles include polyamide, polyester, poly(vinyl
chloride, poly(methacrylic) acid, polymethylmethacrylate,
polycarbonate, polystyrene, and melamine-formaldehyde condensates.
The abrasive particles should have a particle size small enough to
allow them to penetrate into the bonded web 12' and, subject to
that, it is contemplated that abrasive agglomerates, for example
those described in U.S. Pat. No. 4,625,275 and U.S. Pat. No.
4,799,939, may also be used.
[0052] The make-coat resin used, with or without the abrasive
particles, can be any resin known to be suitable for spray-coating
and as a make-coat in scouring materials although, for
environmental reasons, water-based resins are preferred. The resin
should be selected to provide the scouring material with sufficient
flexibility and strength for its intended use, and with the
appropriate degree of water and heat resistance. Suitable resins
include any of the resins listed above for use in the roll-coating
equipment. Preferred resins include water-based phenolic resins
(especially for harder-wearing scouring material) and water-based
latex resins (especially for non-scratch scouring materials for use
in bathrooms etc.).
[0053] The coating weight of the make-coat resin may be in the
range of from 50 to 400 gsm(wet), more specifically 150 to 250
gsm(wet).
[0054] Dispersed throughout the binder or make-coat resin, or
separately applied following application of the resin may be a
crosslinker, filler, catalyst, fragrance, perfume, microcapsules,
antibacterial agents, antimicrobial agents, antifungal agents,
antifoaming agents, thickeners, or fillers.
EXAMPLES
[0055] Scouring materials in accordance with the disclosure, and
methods for producing them, are described in the following
non-limiting examples. All parts and percentages are by weight
unless otherwise indicated. The examples used the following
materials and equipment:
Materials
[0056] Agave fibres: Grade 1 natural fibres from the leaves of
Agave tequilana plants, available through Vinmexco of Stanton,
Calif. 90680, USA. Sisal fibres: natural fibres from the leaves of
Agave sisalana plants, available from CORONA Comercio Industria of
Salvador, Brazil. Coco fibres (also known as coir): natural fibres
from the tissues surrounding the seed of Cocos nucifera (the
coconut palm), available from AVW Vietnam Ltd of Buggenhout,
Belgium. Hemp fibres: natural fibres from the leaves of Musa
textilis plants, available from Caruso GmbH of Ebersdorf, Germany.
Curaua fibres: natural fibres from the leaves of Ananas lucidus
Miller plants, available from Pematec-Triangel do Brazil Ltda. of
Sao Bernardo Do Campo, Brazil. Heat-sensitive fibres: bi-component
polyester fibres having, a linear density of 72 dtex and a length
of 53 mm, available from Fiber Innovation Technology, Inc. of
Johnson City, Tenn., USA; and bi-component copolyester/polyester
fibres having a linear density of 15 dtex and a length of 40 mm,
available from Huvis Corporation of Guangzhou, Guangdong Province,
China. Polyamide fibres: nylon 6.6 fibres having a linear density
of 22 dtex and a length of 40 mm, available from Rhodia SA, of
Paris La Defense, France. Water-based latex resin: SBR latex resin,
available from PolymerLatex GmbH of Marl, Germany. Water-based
acrylic resin: Acrodur 3558 resin, available from BASF of
Ludwigshafen, Germany. Abrasive particles: grade P400 aluminium
oxide particles available, under the trade designation "Corundum
FRPL", from Treibacher Schleifmittel AG of Villach, Austria.
Equipment:
[0057] Web-forming equipment: a pilot or an industrial scale "Rando
Webber" machine, both available from the Rando Machine Co. of
Macedon, N.Y., USA; or a "DOA Webber" machine available from DOA of
Linz, Austria. Roll coating apparatus: equipment available, under
the trade designation PSI-33737, from CAVITEC AG of Tobel, Germany.
Ovens: through-air bonding ovens available from CAVITEC AG of
Tobel, Germany. Spray equipment: Spray guns (type A25 with type
227T nozzles) available, under the trade name "Kremlin", from
KREMLIN REXON of Stains, France.
Example 1
[0058] A fibre mixture comprising, by weight, 80% agave fibres and
20% heat-sensitive fibres (72 dtex linear density) was used in the
pilot scale "Rando Webber" to form a non-woven web of fibres having
a thickness of about 25 mm and a basis weight of about 400
g/m.sup.2. The web was then passed through an oven which was
operated at a temperature of 140.degree. C. The web had a dwell
time of 3 minutes in the oven to soften the heat-sensitive fibres
so that, when the web left the oven and cooled, some of the fibres
in the web were bonded together, giving the web a greater degree of
cohesion.
[0059] The pre-bonded web was then passed between the rolls of the
roll-coating apparatus in which it was impregnated with the latex
resin. The web was passed once again through an oven, operated this
time at 170.degree. C. The web had a dwell time of 8 minutes in the
oven to cure the resin and was then allowed to cool forming a
bonded web.
Examples 2 to 5
[0060] Example 1 was repeated, except that the agave fibres were
replaced with sisal fibres (Example 2); coco fibres (Example 3);
hemp fibres (Example 4); and curaua fibres (Example 5).
Example 6
[0061] Example 1 was repeated, except that the latex resin applied
by the roll coating apparatus was replaced by the acrylic
resin.
Examples 7 and 8
[0062] Example 1 was repeated, except that the bonded web from the
roll-coating apparatus was sprayed on both sides, using the spray
equipment, with a slurry of the latex resin and the abrasive
particles (the latter making up 45% by weight of the slurry). The
slurry was applied at rates of 150 g/m.sup.2 (Example 7) and 200
g/m.sup.2 (Example 8).
Example 9
[0063] A fibre mixture comprising, by weight, 80% agave fibres and
20% polyamide fibres was used in the industrial scale "Rando
Webber" to form a non-woven web of fibres. The web was produced
under operating conditions similar to those used to produce
non-woven webs of synthetic fibres for scouring materials and had a
basis weight of about 220 g/m.sup.2. The web was then passed
between the rolls of the roll-coating apparatus in which it was
impregnated with the latex resin. The web was then passed through
an oven which was operated at a temperature of 150.degree. C. to
cure the resin, the dwell time of the web in the oven being about 1
minute. The web was then allowed to cool, forming a bonded web.
Example 10
[0064] Example 9 was repeated except that the fibre mixture
comprised, by weight, 60% agave fibres and 40% polyamide fibres and
was used in the industrial scale "Rando Webber" to form a non-woven
web of fibres having a basis weight of about 215 g/m.sup.2.
Example 11
[0065] Example 1 was repeated except that the fibre mixture
comprised, by weight, 70% agave fibres, 15% polyamide fibres and
15% heat-sensitive fibres (15 dtex linear density) and was used in
the "DOA Webber" to form a non-woven web of fibres having a
thickness of about 10 mm and basis weight of about 200
g/m.sup.2.
Results
[0066] The webs of Examples 1 to 3 exhibited only a limited
decrease in thickness as a result of the roll-coating step. In each
case, the open structure of the web was retained sufficiently to
provide samples suitable for use as a scouring material. Of these
webs, that of Example 1 exhibited the lowest decrease in thickness
as a result of the roll-coating step. The webs of Examples 4 and 5,
on the other hand, exhibited a substantial decrease in thickness as
a result of the roll-coating step and were considered to be too
compacted to be of use as scouring materials.
[0067] The web of Example 6 indicated that the use of a different
water-based resin for the roll-coating step also did not produce
any significant change in the results.
[0068] The webs of Examples 7 and 8 demonstrated that the bonded
webs could be sprayed with an abrasive slurry in the same way as
conventional non-woven scouring materials formed from synthetic
fibres.
[0069] The webs of Examples 9 and 10, prepared without the use of
heat-sensitive fibres and the formation of a pre-bonded web also
exhibited only a limited decrease in thickness as a result of the
roll-coating step. In each case, the open structure of the web was
retained sufficiently to provide samples suitable for use as a
scouring material.
[0070] The web of Example 11 exhibited very little change in
thickness as a result of the roll-coating step. The open structure
of the web was retained sufficiently to provide samples suitable
for use as a scouring material. It was also observed that less dust
was produced during the web-forming process.
CONCLUSIONS
[0071] The Examples show that non-woven fibrous scouring materials
comprising a substantial amount of natural vegetable fibres can be
produced using a conventional process (in some cases one that
involves the formation of a pre-bonded web), through an appropriate
selection of the natural vegetable fibres employed and by
including, with the natural fibres, an appropriate amount of
crimped synthetic fibres.
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