Nonwoven pad for applying active agents

The present invention provides an topically appliable active agent impregnated nonwoven pad, and the pad is fabricated from a nonwoven web that contains crimped conjugate fibers of spunbond fibers or staple fibers, wherein the nonwoven web is characterized as having autogenous interfiber bonds at the crossover contact points of its fibers throughout the web. The invention additionally provides a method of cleaning or buffing a solid surface with the nonwoven web.

BACKGROUND OF THE INVENTION 
This invention is related to a pad for applying topically appliable active 
agents. More particularly, the invention is related to a disposable 
nonwoven pad that is used to carry, apply and work topically appliable 
active agents, for example, polishing and cleaning agents. 
There are many different nonwoven products that are designed and produced 
to carry and/or work surface active agents. For example, there are 
nonwoven pads that are designed to apply and work surface active agents, 
such as polishing wax and dermatological medicaments. U.S. Pat. Nos. 
3,537,121 and 3,910,284, for example, disclose a buffing pad that cleans 
or restores luster without scratching or abrading the target surface that 
is being cleaned or buffed. The buffing pad is fabricated from a synthetic 
fiber web that is bonded with an external elastomeric binder. Although 
this type of buffing pad is highly useful, the use of an external binder 
not only complicates the production process of the pads but also the 
selection of the external binder must be carefully made to ensure 
durability of the pad and physical and chemical compatibilities of the 
binder with the fibers forming the pad. In addition, the binder must not 
hinder the performance of the nonwoven pad. 
Another group of active agent nonwoven products are nonwoven webs that 
carry active agents for various applications. For example, U.S. Pat. Nos. 
4,793,941 to Serviak et al. and 5,053,157 to Lloyd disclose a laundry 
detergent impregnated nonwoven web which is highly suitable for delivering 
a proper amount of detergent for each wash load. U.S. Pat. No. 4,775,582 
to Abba et al. discloses a meltblown nonwoven wet wipe for personal care 
uses. U.S. Pat. No. 4,683,001 to Floyd discloses an automotive wash and 
dry wipe that contains a polishing composition. U.S. Pat. No. 3,965,519 to 
Hermann discloses a disposable floor wiper, preferably of a natural fiber 
web, which is impregnated with a floor-coating composition. Although the 
prior art active agent impregnated nonwoven pads of microfibers and 
natural fibers are highly useful, they may not be particularly suitable 
for certain applications in which a large amount of an active agent needs 
to be delivered and/or high strength and abrasion resistance are required. 
For heavy duty wiping and polishing applications, it is desirable that an 
active agent applying or polishing pad exhibits high strength properties 
as well as has a capacity for carrying a large amount of active agents 
compared to the weight of the pad. It is also desirable for the polishing 
pad to have a compressible resiliency such that the amount of release of 
the active agent applied on the pad can be controlled by applying varying 
levels of hand pressure and that a portion of the released active agent 
can be re-absorbed when the pressure is reduced should more than necessary 
amount was released. It is also highly important for economical reasons 
that the interfiber structure of the pad allows thorough release of the 
absorbed active agent during use such that the used pad does not retain a 
significant amount of the agent. In addition, it is highly desirable for 
the pad to have high physical strength and abrasion resistance such that 
the pad can be used to apply and spread the active agent on the target 
surface as well as buff or polish the surface. Furthermore, it is 
desirable to have the pad produced from a non-abrasive material such that 
the pad does not abrade or damage the finishing of the target surface. For 
example, an automotive polishing pad should desirably be able to carry a 
sufficient amount of a polishing agent for at least one complete 
application and is made from a non-abrading material such that the painted 
surface is not scratched or damaged from the use of the pad. Additionally, 
it is highly desirable for the pad to have sufficient strength to be 
useful not only as an applicator of the polishing agent but also as a 
buffing or polishing pad. 
SUMMARY OF THE INVENTION 
There is provided in accordance with the present invention an active agent 
impregnated nonwoven pad, which is impregnated with a topically appliable 
active agent. The pad is fabricated from a nonwoven web that contains 
crimped conjugate fibers of spunbond fibers or staple fibers. The nonwoven 
web can be characterized as having autogenous interfiber bonds at the 
crossover contact points of its fibers throughout the web, wherein the 
nonwoven pad is impregnated with a topically appliable active agent. 
Desirably, the crimped conjugate fibers of the present invention have at 
least 2 crimps per extended inch (2.54 cm) as measured in accordance with 
ASTM D-3937-82. 
The present invention additionally provides a method of cleaning or buffing 
a solid surface. The method has the steps of applying a cleaning or 
polishing agent on the solid surface, and spreading and rubbing the agent 
against the surface with a crimped conjugate fiber nonwoven web, wherein 
the nonwoven web contains crimped conjugate fibers selected from spunbond 
fibers and staple fibers. The conjugate fibers having at least 2 crimps 
per extended inch (2.54 cm) as measured in accordance with ASTM D-3937-82, 
and the nonwoven web containing autogenous interfiber bonds at the 
crossover contact points of the conjugate fibers throughout the web. 
The nonwoven pad of the present invention is highly suitable for polishing 
and buffing applications. In addition, the pad, which has a porous, lofty 
structure and yet exhibits high resilience, strength and abrasion 
resistance, is adapted for impregnating a large amount of active agents 
and for evenly and selectively applying the impregnated active agents. The 
pad is also nonabrasive and gentle enough for polishing typical solid 
target surfaces. 
The term "spunbond fibers" as used herein indicates fibers formed by 
extruding molten thermoplastic polymers as filaments from a plurality of 
relatively fine, usually circular, capillaries of a spinneret, and then 
rapidly drawing the extruded filaments by an eductive or other well-known 
drawing mechanism to impart molecular orientation and physical strength to 
the filaments. The drawn fibers are deposited onto a collecting surface in 
a highly random manner to form a nonwoven web having essentially a uniform 
density, and then the nonwoven web is bonded to impart physical integrity 
and strength. The processes for producing spunbond fibers and webs 
therefrom are disclosed, for example, in U.S. Pat. Nos. 4,340,563 to Appel 
et al., 3,802,817 to Matsuki et al. and 3,692,618 to Dorschner et al. A 
particularly suitable conjugate spunbond fiber web production process is 
disclosed in commonly assigned U.S. patent application Ser. No. 
07/933,444, U.S. Pat. No. 5,382,400 to Pike et al. filed Aug. 21, 1992. 
The term "staple fibers" refers to noncontinuous fibers. Staple fibers are 
produced with a conventional fiber spinning process and then cut to a 
staple length, from about 1 inch to about 8 inches. Such staple fibers are 
subsequently carded, wet-laid, or air-laid and then thermally bonded to 
form a nonwoven web. The term "meltblown webs" refers to nonwoven webs 
formed by extruding a molten thermoplastic polymer through a spinneret 
containing a plurality of fine, usually circular, die capillaries as 
molten filaments or fibers into a high velocity, usually heated gas stream 
which attenuates or draws the filaments of molten thermoplastic polymer to 
reduce their diameter. After the fibers are formed, they are carried by 
the high velocity gas stream and are deposited on a forming surface to 
form an autogenously bonded web of randomly disbursed, highly entangled 
meltblown microfibers. Such a process is disclosed, for example, in U.S. 
Pat. 3,849,241 to Butin. Typically, the polymer chains of meltblown fibers 
are not highly oriented, and thus meltblown fibers exhibit substantially 
weaker strength properties when compared to spunbond and staple fibers. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention provides a nonwoven pad that is highly suitable for 
impregnating a large amount of topically appliable, surface active agents 
and is highly adapted for evenly and selectively releasing the impregnated 
active agents. The nonwoven pad is also highly suitable for buffing and 
polishing applications. The pad is produced from a nonwoven web that 
contains crimped spunbond or staple conjugate fibers, and the conjugate 
fibers have at least two component polymers having different melting 
points. The fibers have an average diameter between about 8 .mu.m and 
about 50 .mu.m, desirably between about 10 .mu.m and about 30 .mu.m. The 
structure of a suitable nonwoven web for the present invention can be 
characterized as having autogenous interfiber bonds at the crossover 
contact points of the fibers throughout the nonwoven web. The nonwoven 
web, which contains crimped fibers and interfiber bonds, has a structure 
that is lofty and yet compressibly resilient. Alternatively stated, the 
nonwoven web is flexible and readily compressible and yet upon release of 
compacting pressure, essentially completely recovers to the initial 
uncompressed structure. The nonwoven webs suitable for the present 
invention typically have a density between about 0.01 g/cm.sup.3 and about 
0.1 g/cm.sup.3, desirably between about 0.02 g/cm.sup.3 to about 0.9 
g/cm.sup.3, and a basis weight of about 0.3 ounces per square yard (osy) 
to about 20 osy (about 10 to about 680 g/m.sup.2), desirably about 0.5 osy 
to about 15 osy (about 17 to about 510 g/m.sup.2). Desirably, the total 
void space of the suitable nonwoven webs occupies between about 80% and 
about 99%, more desirably between about 85% and about 98.5%, of the total 
volume of the nonwoven webs. 
Suitable conjugate fibers for the nonwoven pad contain at least two 
component polymers that have different melting points. The component 
polymers occupy distinct cross sections along substantially the entire 
length of the fibers, and the cross section that contains the lowest 
melting component polymer occupies at least some portion, desirably at 
least half, of the peripheral surface of the fibers. Suitable conjugate 
fibers may have a side-by-side configuration or sheath-core configuration, 
e.g., eccentric configuration or concentric configuration. Of the 
sheath-core configurations, particularly suitable are eccentric 
configurations in that they are more amenable to crimp imparting 
processes. 
In accordance with the present invention, the crimp level of the conjugate 
fibers can be changed to impart different properties to the web, including 
different density, strength, softness and texture, as well as the active 
agent retaining capacity of the nonwoven web. In general, a nonwoven web 
containing fibers having a higher crimp level provides a loftier and lower 
density structure that is highly adapted for carrying a larger amount of 
active agents and for carrying higher viscosity fluids. In addition, 
crimps in the fibers impart a soft, cloth-like texture in the web. 
Desirably, suitable fibers for the present nonwoven web have at least 
about 2 crimps per extended inch (2.54 cm), particularly between about 2 
and about 50 crimps per extended inch, more particularly between about 5 
and about 30 crimps per extended inch, as measured in accordance with ASTM 
D-3937-82. 
The component polymers of suitable conjugate fibers desirably are selected 
to have a melting point difference between the highest melting component 
polymer and the lowest melting component polymer of at least about 
5.degree. C., more desirably at least about 10.degree. C., most desirably 
at least about 30.degree. C., such that the lowest melting component 
polymer can be melted and rendered adhesive without melting the higher 
melting component polymers of the fibers, thereby the difference in the 
melting points can be advantageously used to bond nonwoven webs containing 
the conjugate fibers. When a nonwoven web containing the conjugate fibers 
is heated to a temperature equal to or higher than the melting point of 
the lowest melting component polymer but below the melting point of the 
highest melting component polymer, the melted portions of the fibers form 
autogenous interfiber bonds, especially at the crossover contact points, 
throughout the web while the high melting polymer portions of the fibers 
maintain the physical and dimensional integrity of the web. Desirably, the 
component polymers are selected additionally to have different 
crystallization and/or solidification properties to impart latent 
crimpability in the fibers. While it is not wished to limit the invention 
to a particular theory, it is believed that, in general, conjugate fibers 
containing component polymers of different crystallization and/or 
solidification properties possess subsequently activatable "latent 
crimpability". The latent crimpability is imparted in the conjugate fibers 
because of incomplete crystallization of one or more of the slow 
crystallizing component polymers. When such conjugate fibers are exposed 
to a heat treatment or mechanical drawing process, the component polymers 
further crystallize. The crystallization disparity among the component 
polymers of the conjugate fibers during the subsequent crystallization 
process causes the fibers to crimp, unless the component polymers of the 
fibers are concentrically arranged and thus dimensionally restrained from 
forming crimps. 
An exemplary process for producing highly suitable spunbond conjugate 
fibers having such latent crimpability and nonwoven webs containing the 
conjugate fibers is disclosed in commonly assigned U.S. patent application 
Ser. No. 07/933,444, U.S. Pat. No. 5,382,400 to Pike et al. filed Aug. 21, 
1992, which in its entirety is herein incorporated by reference. Briefly, 
the process for making crimped conjugate fiber web disclosed in the patent 
application includes the steps of meltspinning continuous multicomponent 
polymeric filaments, at least partially quenching the multicomponent 
filaments so that the filaments have latent crimpability, activating the 
latent crimpability and drawing the filaments by applying heated drawing 
air, and then depositing the crimped, drawn filaments onto a forming 
surface to form a nonwoven web. The spunbond fiber forming process of the 
patent application is particularly desirable for the present nonwoven web 
in that the heated air crimping and drawing process provides a convenient 
way to impart crimps and control the crimp density, i.e., the number of 
crimps per unit length of a fiber. In general, a higher drawing air 
temperature results in a higher number of crimps. 
As indicated above, the deposited nonwoven web is bonded by heating the 
conjugate fiber web to melt or render adhesive the lowest melting 
component polymer of the conjugate fibers and, thus, allowing the fibers 
to form interfiber bonds, especially at cross over contact points of the 
fibers. Bonding processes suitable for the present invention include 
through-air-bonding processes, oven bonding processes and infrared bonding 
processes. Of these, particularly suitable are through-air-bonding 
processes that apply a penetrating flow of heated air through the nonwoven 
web to quickly and evenly raise the temperature of the web. In addition, 
through-air-bonding processes can be modified to impart a fiber density 
gradient in the nonwoven web during the bonding process. When a high flow 
rate of heated air is applied onto the nonwoven web during the bonding 
process, the compacting pressure of the air flow and the weight of the 
fibers create an increasing fiber density gradient in the direction of the 
air flow, forming a bonded nonwoven web having a fiber density gradient. A 
nonwoven web having an increasing fiber density gradient in the direction 
of its thickness provides two distinct surfaces having different textural 
and physical properties, a low fiber density surface and a high fiber 
density surface. In general, the low fiber density surface of such bonded 
nonwoven webs provides a soft surface that is suited for applying the 
impregnated active agent, while the high fiber density surface provides a 
more rigid, abrasion resistant surface that is suited for buffing and 
scrubbing actions. 
As a particularly desirable embodiment of the present invention, nonwoven 
webs suitable for the nonwoven pad are produced from a nonwoven web of 
crimped spunbond conjugate filaments. As stated above, the crimp level 
and, thus, the interfiber void structure of spunbond conjugate filament 
nonwoven webs can be conveniently controlled during the production 
process, providing a highly controllable in-situ process for conveniently 
producing customized or particularized nonwoven webs for various pad 
applications to accommodate different types and viscosities of active 
agents. In addition, spunbond nonwoven processes, unlike staple fiber web 
forming processes, do not have separate filament cutting, i.e., staple 
fiber forming, and web-forming steps, thereby making the processes more 
economical than the processes for forming staple fiber webs. Furthermore, 
the continuous filaments of spunbond nonwoven webs tend to provide higher 
strength nonwoven webs than staple fiber webs and are less likely to 
produce lint, i.e., loose fibers, that may interfere with the performance 
of the pad. 
Conjugate fibers suitable for the present invention can be produced from a 
wide variety of thermoplastic polymers that are known to form fibers. The 
component polymers are selected in accordance with the above-described 
selection criteria including melting points and crystallization 
properties. Suitable polymers for the present invention are selected from 
polyolefins, polyamides, polyesters, copolymers containing acrylic 
monomers, and blends and copolymers thereof. Suitable polyolefins include 
polyethylene, e.g., linear low density polyethylene, high density 
polyethylene, low density polyethylene and medium density polyethylene; 
polypropylene, e.g., isotactic polypropylene, syndiotactic polypropylene, 
blends thereof and blends of isotactic polypropylene and atactic 
polypropylene; and polybutylene, e.g., poly(1-butene) and poly(2-butene); 
polypentene, e.g., poly-4-methylpentene-1 and poly(2-pentene); as well as 
blends and copolymers thereof. Suitable polyamides include nylon 6, nylon 
6/6, nylon 10, nylon 4/6, nylon 10/10, nylon 12, nylon 6/12, nylon 12/12, 
and hydrophilic polyamide copolymers such as copolymers of caprolactam and 
an alkylene oxide, e.g., ethylene oxide, and copolymers of hexamethylene 
adipamide and an alkylene oxide, as well as blends and copolymers thereof. 
Suitable polyesters include polyethylene terephthalate, polybutylene 
terephthalate, polycyclohexylenedimethylene terephthalate, and blends and 
copolymers thereof. Acrylic copolymers suitable for the present invention 
include ethylene acrylic acid, ethylene methacrylic acid, ethylene 
methylacrylate, ethylene ethylacrylate, ethylene butylacrylate and blends 
thereof. Particularly suitable polymers for the present invention are 
polyolefins, including polyethylene, e.g., linear low density 
polyethylene, low density polyethylene, medium density polyethylene, high 
density polyethylene and blends thereof; polypropylene; polybutylene; and 
copolymers as well as blends thereof. Of the suitable polymers, 
particularly suitable polymers for the high melting component of conjugate 
fibers include polypropylene, copolymers of polypropylene and ethylene and 
blends thereof, more particularly polypropylene; and particularly suitable 
polymers for the low melting component include polyethylenes, more 
particularly linear low density polyethylene, high density polyethylene 
and blends thereof. In addition, the polymer components may contain 
additives or thermoplastic elastomers for enhancing the crimpability 
and/or lowering the bonding temperature of the fibers, and enhancing the 
abrasion resistance, strength and softness of the resulting webs. For 
example, the low melting polymer component may contain about 5 to about 
20% by weight of a thermoplastic elastomer such as an ABA' block copolymer 
of styrene, ethylene-butylene and styrene. Such copolymers are 
commercially available and some of which are identified in U.S. Pat. No. 
4,663,220 to Wisneski et al. An example of highly suitable elastomeric 
block copolymers is KRATON G-2740. Another group of suitable additive 
polymers is ethylene alkyl acrylate copolymers, such as ethylene butyl 
acrylate, ethylene methyl acrylate and ethylene ethyl acrylate, and the 
suitable amount to produce the desired properties is from about 2 wt % to 
about 50 wt %, based on the total weight of the low melting polymer 
component. Yet other suitable additive polymers include polybutylene 
copolymers and ethylenepropylene copolymers. 
In accordance with the present invention, two-component conjugate fibers, 
bicomponent fibers, are particularly useful for the invention, and 
suitable bicomponent fibers have from about 10% to about 90%, desirably 
from about 20% to about 80%, more desirably from about 40% to about 60%, 
by weight of a low melting polymer and from about 90% to about 10%, 
desirably from about 80% to about 20%, more desirably about 60% to about 
40%, by weight of a high melting polymer. 
The conjugate fiber nonwoven pads of the present invention in general are 
oleophillic since most of the above-illustrated suitable fiber-forming 
polymers are naturally oleophillic. Consequently, oil based active agents 
and emulsified active agents are readily absorbed and retained by the 
present nonwoven web. When aqueous or hydrophilic active agents are 
desired to be impregnated in the nonwoven pad, the conjugate fibers or the 
nonwoven web that forms the pad may be hydrophilically modified. Any of a 
wide variety of surfactants, including ionic and nonionic surfactants, may 
be employed to hydrophilically modify the pad. Suitable surfactants may be 
internal modifiers, i.e., the modifying compounds are added to the polymer 
composition prior to spinning or forming fibers, or topical modifiers, 
i.e., the modifying compounds are topically applied during or subsequent 
to the formation of fibers or nonwoven webs. An exemplary internal 
modification process is disclosed in U.S. Pat. No. 4,578,414 to Sawyer et 
al. An exemplary topical modification process is disclosed in U.S. Pat. 
No. 5,057,361 to Sayovitz et al. Both of the patents are herein 
incorporated by reference. Illustrative examples of suitable surfactants 
include silicon based surfactants, e.g., polyalkylene-oxide modified 
polydimethyl siloxane; fluoroaliphatic surfactants, e.g., perfluoroalkyl 
polyalkylene oxides; and other surfactants, e.g., actyl-phenoxypolyethyoxy 
ethanol nonionic surfactants, alkylaryl polyether alcohols, and 
polyethylene oxides. Commercially available surfactants suitable for the 
present invention include various poly(ethylene oxide) based surfactants 
available under the tradename Triton, e.g., grade X-102, from Rohm and 
Haas Crop; various polyethylene glycol based surfactants available under 
the tradename Emerest, e.g., grades 2620 and 2650, from Emery Industries; 
various polyalkylene oxide modified polydimethylsiloxane based surfactants 
available under the tradename Silwet, e.g., grade Y12488, from OSI 
Specialty Chemicals; and alkenyl succinamide surfactants available under 
the tradename Lubrizol, e.g., grade OS85870, from Lubrizol Crop.; and 
polyoxyalkylene modified fluoroaliphatic surfactants available from 
Minnesota Mining and Manufacturing Co. The amount of surfactants required 
and the hydrophilicity of modified fibers for each application will vary 
depending on the type of surfactant selected and the component polymers 
used. In general, the surfactant may be added, topically or internally, in 
the range of from about 0.1 to about 5%, desirably from about 0.3% to 
about 4%, by weight based on the weight of the fiber or the nonwoven web. 
In accordance with the present invention, a wide variety of topically 
appliable active agents can be impregnated in and used with the present 
nonwoven pad, which include synthetic oil based active agents, e.g. 
paraffin wax, shoes and garment polishing waxes and mineral oil; natural 
active agents, e.g., bees wax, carnauba wax, candelilla wax, and castor 
oil; emulsified active agents, e.g., soaps, detergents, body lotions and 
wax emulsions; aqueous active agents, e.g., dermatological medicaments, 
germicidal solutions and bleaches; and others, e.g., alcohols, perfumes 
and dermatological cleansers. 
The active agents can be impregnated into the nonwoven pad by any 
conventional techniques useful for impregnating or applying liquid on a 
porous material, such as spraying, dipping, coating and printing. 
Optionally, once the nonwoven pad is impregnated with an active agent, the 
liquid content of the agent can be evaporated to provide highly stable and 
low weight nonwoven pads that can be reactivated by subsequently applying 
an appropriate solvent or water. 
The treated nonwoven pads of the present invention are highly suitable for 
carrying and evenly applying topically appliable active agents. The 
nonwoven pads are particularly suited for high viscosity active agents, 
e.g., polishing wax, that cannot be impregnated in a large amount in and 
are not easily released from prior art microfiber nonwoven webs and 
cellulosic natural fiber webs that have small interfiber capillary 
structures which firmly hold the active agents and hinders the exuding 
movement of the agents from the web even when pressure is applied. The 
highly porous and lofty structure of the present nonwoven pads provides a 
unique void structure that is excellent for absorbing and carrying a large 
amount of active agents, and the resilient property of the nonwoven pad 
allows selective, i.e., in response to varying degrees of applied 
pressure, and thorough release of the absorbed agents. In addition, the 
high resiliency and the relatively large void structure, compared to 
microfiber webs, of the present pad promote the release and reabsorption 
of absorbed active agents in response to hand pressure. Moreover, the 
nonwoven pad which contains evenly distributed autogenous interfiber bonds 
exhibits high abrasion resistance and physical strength that are highly 
useful for applying the active agent over a large area, applying the 
absorbed agent over even a rough surface, and buffing or polishing a 
surface without scratches or abrasions. Additionally, the strength of the 
interfiber bonds which are formed by the component polymer of the fibers 
of the nonwoven web, and not by an externally applied adhesive, is 
generally not affected by the impregnated active agent, i.e., the nonwoven 
pad exhibits unimpaired wet strength. Consequently, the present nonwoven 
web is highly useful for various active agent applying and buffing 
applications. Yet another advantageous characteristic of the pad is that 
the crimped fibers and the autogenously bonded interfiber structure of the 
pad provide cloth-like pleasing textural properties. The nonwoven pad 
having these useful properties can be used as a carrier and non-abrading 
applicator of a wide variety of active agents, including automotive 
polishing agents, waxes, cosmetic compounds, topical medicaments, 
cleansers, moisturizers, fragrances, germicidal solutions and the like, as 
well as a buffing or polishing pad for the active agents. 
As an additional embodiment of the present invention, the conjugate fibers 
forming the nonwoven web may have a variety of different cross sectional 
shapes in addition to the conventional round shape in order to impart 
additional advantageous functionalities in the nonwoven web, such as 
increased active agent holding capacity and improved active agent holding 
stability. Suitable cross sectional shapes include ribbon, bilobal, 
trilobal, quadlobal, pentalobal and hexalobal shapes. Methods of forming 
shaped fibers are known to those skilled in the art. As a general rule, 
shaped fibers are prepared by extruding the fiber compositions through a 
die orifice generally corresponding to the desired shape. Such a method is 
described, for example, in U.S. Pat. No. 2,945,739 to Lehmicke. 
As yet another embodiment of the present invention, the nonwoven pad can be 
laminated to variety of different materials. For example, the pad can be 
laminated to a liquid barrier layer, e.g., film layer, so that the 
impregnated agent is released only through the nonwoven side of the pad. 
The pad can also be laminated to a scouring or abrasive layer, e.g., a 
steel wool, so that the large active agent holding capacity and the 
strength properties can be complementarily added to a highly abrasive 
property of the abrasive material. As yet another embodiment of the 
present invention, the high strength nonwoven pad can be impregnated with 
an abrasive compound, e.g., metal polishing agent or abrasive particles, 
to be used as a hard surface polishing pad.

The following examples are provided for illustration purposes and the 
invention is not limited thereto. 
EXAMPLES 
Example 1 
(Ex1) 
A 3 osy (102 g/m.sup.2) spunbond bicomponent fiber web was produced using 
the production process disclosed in aforementioned U.S. patent application 
Ser. No. 07/933,444. A linear low density polyethylene (LLDPE), Aspun 
6811A, which is available from Dow Chemical, was blended with 2 wt % of a 
TiO.sub.2 concentrate containing 50 wt % of TiO.sub.2 and 50 wt % of a 
polypropylene, and the blend was fed into a first single screw extruder. A 
polypropylene, PD3445, which is available from Exxon, was blended with 2 
wt % of the above-described TiO.sub.2 concentrate, and the blend was fed 
into a second single screw extruder. The extruded polymers were spun into 
round bicomponent fibers having a side-by-side configuration and a 1:1 
weight ratio of the two component polymers using a bicomponent spinning 
die, which had a 0.6 mm spinhole diameter and a 6:1 L/D ratio. The melt 
temperatures of the polymers fed into the spinning die were kept at 
450.degree. F. (232.degree. C.), and the spinhole throughput rate was 0.6 
gram/hole/minute. The bicomponent fibers exiting the spinning die were 
quenched by a flow of air having a flow rate of 45 standard feet.sup.3 
/minute/inch (0.5 m.sup.3 /minute/cm) spinneret width and a temperature of 
65.degree. F. (18.degree. C.). The quenching air was applied about 5 
inches (13 cm) below the spinneret, and the quenched fibers were drawn in 
an aspirating unit of the type which is described in U.S. Pat. No. 
3,802,817 to Matsuki et al. The aspirator was equipped with a temperature 
controlled aspirating air source, and the feed air temperature was kept at 
about 350.degree. F. (177.degree. C.). The quenched fibers were drawn with 
the heated feed air to attain a 2.5 denier. Then, the drawn fibers were 
deposited onto a foraminous forming surface with the assist of a vacuum 
flow to form an unbonded fiber web. The unbonded fiber web was bonded by 
passing the web through a through-air bonder which is equipped with a 
heated air source. The heated air velocity and the temperature of the 
heated air were 200 feet/minute (61m/min) and 262.degree. F. (128.degree. 
C.), respectively. The residence time of the web in the hood was about 1 
second. The resulting bonded web had a thickness of 0.14 inches (0.36 cm) 
and a density of 0.027 g/cm.sup.3. 
The bonded nonwoven web was cut into a 3 inch by 3 inch (7.6 cm.times.7.6 
cm) square test specimens and weighed. The square pads were tested for its 
active agent absorbent and delivery capacities using a mineral oil, baby 
oil from Johnson and Johnson, and a liquid dish washing detergent. The pad 
specimen was submerged in a mineral oil bath or a soap bath for one 
minute, and then the soaked pad was taken out of the bath and allowed to 
drip excess fluid for one minute. The weight of the active agent 
impregnated pad was measured to determine the absorbent capacity of the 
nonwoven pad. Then the impregnated pad was placed on a metal block having 
a 3 inch by 3 inch (7.6 cm.times.7.6 cm) planar surface, and a 12 pound 
(5.4 kg) flat weight, which completely covered the pad and provided a 1.2 
psi (0.08 kg/cm.sup.3) pressure, was placed over the pad squeezing the 
active agent out from the pad. The released active agent was allowed to 
flow away from the pad. Again, the pad was weighed to determine the amount 
of the active agent released (delivered) under the pressure. The results 
are shown in Table 1. 
Comparative Example 1 
(C1) 
A meltblown web having a basis weight of 1.1 osy (37 g/m.sup.2) was 
produced in accordance with the procedures described in U.S. Pat. No. 
4,307,143 to Meitner. The web was produced by meltblowing polypropylene, 
which was obtained from Himont, grade PF015, through a die having a row of 
apertures and impinging heated air at the die exit to draw the filaments 
forming microfibers which were collected on a forming wire to form an 
autogenously bonded meltblown web. Because meltblown nonwoven webs 
typically do not have physical strength properties that are required for 
active agent delivery applications, the nonwoven webs were point bonded to 
have a total bonded surface area of 15%. The meltblown web was bonded by 
feeding the web into the nip of a steel calender roll and a steel anvil 
roll. The calender roll had about 117 raised square bonding points per 
square inch (18 points/cm.sup.2). The bonding rolls were heated to about 
220.degree. F. (104.degree. C.) and applied a nip pressure of about 200 
lbs/lineal inch (35 kg/lineal cm). The bond points of the bonded meltblown 
web virtually lost their fibrous structure and formed film-like regions. 
The bonded meltblown web was tested for the absorbent and delivery 
capacities in accordance with the procedure outlined in Example 1. The 
results are shown in Table 1. 
Comparative Example 2 
(C2) 
Comparative example 1 was repeated, except a 2 osy (68 g/m.sup.2) meltblown 
web was prepared and tested for this comparative example. 
TABLE 1 
______________________________________ 
Amount Delivered 
Web Absorbent under applied pressure 
Density Capacity Amount % of Absorbed 
(g/cc) Fluid (g/g) (g/g) (%) 
______________________________________ 
Ex1 0.027 Oil 20.1 10.7 53 
Soap 32.8 19.8 60 
C1 0.089 Oil 6.3 2.0 32 
Soap 14.5 8.2 57 
C2 0.096 oil 6.0 1.9 32 
Soap 12.0 6.1 51 
______________________________________ 
Absorbent Capacity = weight of the active agent absorbed per unit weight 
of the nonwoven web. 
Amount Delivered = weight of the active agent released under pressure per 
unit weight of the nonwoven web. 
The capacity results show that the present conjugate fiber nonwoven web has 
a significantly higher absorbent capacity compared to meltblown nonwoven 
webs and that the conjugate fiber web more readily releases the absorbed 
active agent in response to applied pressure. The results demonstrate that 
the present conjugate fiber nonwoven web has an interfiber structure that 
is highly suitable for absorbing or carrying and delivering various active 
agents. Although it is not wished to be bound by any theory, it is 
believed that meltblown fiber webs and natural fiber webs tend to have a 
small interfiber capillary structure that does not accept a large amount 
of active agents and does not readily release the agents once they are 
absorbed into the capillary structure. In contrast, the large interfiber 
void configuration, high resiliency and strength of the present conjugate 
fiber web provide a unique web structure that makes the present nonwoven 
web highly suitable for active agent delivery systems. 
Example 2 
(Ex2) 
A 2 osy bicomponent nonwoven web was prepared in accordance with Example 1. 
The nonwoven web was tested for its grab tensile strength in accordance 
with Federal Standard Methods 191A, Method 5100 (1978). The grab test for 
tensile strength measures the breaking load a nonwoven web at a constant 
rate of extension in the machine direction (MD) or the cross-machine 
direction (CD). The results are shown in Table 2. 
Comparative Example 3 
(C3) 
The meltblown web of Comparative Example 1 was tested for its grab tensile 
strength. The results are shown in Table 2. 
TABLE 2 
______________________________________ 
Grab Tensile 
MD CD 
Example (lbs) (lbs) 
______________________________________ 
Ex2 16 15 
C3 4 3 
______________________________________ 
As can be seen from the above results, the present conjugate fiber web 
exhibits high strength properties compared to the meltblown web even 
though the meltblown web was point bonded to improve the strength 
properties. Correspondingly, in combination with other advantageous 
properties, e.g., high resiliency, abrasion resistance and absorbency, the 
nonwoven web is an excellent material for buffing and polishing 
applications as well as active agent delivery applications. In addition, 
the conjugate fiber nonwoven web is a nonabrasive buffing or polishing 
material that is gentle to the target surface since the nonwoven web 
itself does not contain any abrasive components. However, because of the 
advantageous strength and absorbent properties of the nonwoven web, the 
web can easily be modified as an abrading pad by impregnating it with an 
abrasive material, e.g., calcium carbonate particles, iron particles or 
sand.