Process for treating a fibrous material and article thereof

A process for treating a fibrous material which includes the steps of: 1) providing a liquid suspension composed of fibrous material; 2) intermixing the liquid suspension of fibrous material with a treatment over a time period T.sub.1 --wherein the treatment requires a period of time T.sub.R sufficient to treat the fibrous material; 3) depositing the liquid suspension of fibrous material and intermixed treatment onto a forming surface to form a layer and removing a substantial portion of the liquid, over a period of time T.sub.2 ; and 4) applying pressurized jets of a liquid to the layer of fibrous material to wash unused treatment from the fibrous material within a period of time T.sub.3. Periods of time T.sub.1, T.sub.2 and T.sub.3 are immediately consecutive and amount to a total period of time at least as great as T.sub.R. Also disclosed is a hydraulically entangled structure composed of: 1) at least one layer a wet-laid nonwoven web containing fibrous cellulosic material; and 2) colorfast dye imparting color to the fibrous cellulosic material such that the fibrous cellulosic material is colorfast.

FIELD OF THE INVENTION 
This invention relates to a method of treating a fibrous material. The 
invention also relates to a cellulosic material having durable color. 
BACKGROUND OF THE INVENTION 
A demand exists for cellulose fiber containing nonwoven materials that are 
colored, have textile aesthetics and performance, and remain fast under 
harsh chemical and abrasive use. It is highly desirable for such nonwoven 
materials to be laundrable and durable. It is also desirable for such 
substrates to be lightfast. 
These nonwoven materials can be used to replace traditional textiles in 
applications including, but not limited to, wipers, wearing apparel, 
equipment protection, and bedding. Such products are used in a wide range 
of industries including: manufacturing, medical, printing, spray paint, 
garment and food services. 
Insoluble colorant pigments are used to color cellulose fiber containing 
nonwoven materials. These pigments are generally inorganic or contain a 
synthetic organic base. A fixing agent is typically used to improve 
fastness because these colorant pigments are insoluble in the application 
medium and do not readily migrate into cellulose fibers or fix onto them. 
Useful fixing agents include alum, caseins, starches, acrylics, rosin 
sizes, polyvinyl alcohols, and cationic colorant fixatives. Generally 
speaking, these fixatives only modestly improve durability. 
Soft polymeric adhesive binders or resins are also used as fixing agents. 
They improve durability by encapsulating and binding the insoluble pigment 
to fiber surfaces. Binders and resins have limited use because they are a 
surface treatment and generally have only moderate fastness. Deeper shades 
of color require excess pigment and binder or resin that tend to rub off 
or crock. Moreover, high levels of pigment act as fillers and can 
physically weaken a sheet. Binders or resins also stiffen nonwoven 
materials and impair textile-like aesthetics while often negatively 
impacting liquid distribution and absorbency properties. 
Binders and resins are often soluble in many common volatile and 
semi-volatile commercial and industrial liquids and solvents and could 
leach from the nonwoven material leaving undesirable residues and streaks. 
When used on hot surfaces or at high temperature, binder or resin on 
colored nonwoven materials may migrate, soften, degrade, alter the 
nonwoven material properties and/or leave residues. Another disadvantage 
of binder and resin coloring systems is that they are often added to dried 
sheets using size presses, saturation techniques or printing operations 
and then again dried. Many binders are also applied as a secondary process 
off-line to the basesheet production which also increases costs. 
Dye colorants are also used to color cellulose fibers and cellulose fiber 
containing nonwoven materials. Dyestuffs, dye colorants, or dyes are 
generally categorized into numerous classes according to application. 
These categories include: basic, acid, direct (including cationic 
directs), mordant, azoic, disperse, reactive, sulfur and vat dyes. These 
dyes have a wide range of cost, dyeing properties and fastness. In 
addition, the method of applying such dyes varies widely from simple 
introduction to suspended stocks and webs to multistage chemical 
processes. 
Dyes are physically or chemically bonded to fiber to provide durable color. 
They are bonded typically by one or more forces including physical 
entrapment, hydrogen bonding, van der Waals forces, coordinately bonded, 
ionic forces or covalent bonds. Generally speaking, dyes are usually fast 
or permanent in only some aspects or under certain conditions. 
It is desirable for dye colorants to be resistant to light and water. It is 
also desirable for a dye colorant to withstand other influences 
encountered in commercial and industrial applications of cellulose fiber 
containing nonwoven materials. These include, but are not limited to, 
bleaches and detergents used during laundering and soaking for stain 
removal; cleaners including acids such as vinegar and bases; and a large 
list of industrial chemicals including oils, cutting oils, and solvents 
having a wide range of dipole moments such as: acetone, methylene 
chloride, 1,1,1 trichloroethane and various alcohols, ketones, benzene, 
naphthalene and mineral spirits. 
Generally speaking, basic dyes have poor light fastness and are susceptible 
to uneven coloring of cellulose fibers (e.g., paper fibers). Acid dyes are 
readily susceptible to water bleeding because of their low affinity to 
cellulose fibers. Direct or substantive dyes will color cellulose fibers 
without the use of dyeing assistants or mordants. However, they tend to 
lack the overall chemical fastness needed even with the use of mordanting, 
cationic fixing agents, formaldehydes or coupling compounds. Direct dyes 
lack overall fastness since the forces binding them are easily broken. 
Generally speaking, mordant dyes have no affinity for cellulose fibers and 
require use of a metallic oxide treatment for good fastness properties. 
Azoic dyes require coupling of two dye components onto the fiber but lack 
overall chemical fast requirements and are normally limited to only a few 
cellulosic applications. Disperse dyes are typically used to color 
hydrophobic fibers and are fine-size organic compounds with limited 
solubility and crock resistance. 
Reactive dyes can be described as acid, basic or mordant dye with an 
attached reactive group that is capable of covalent bonding to a cellulose 
fiber. 
Good fastness is typically obtained by converting soluble compounds into 
relatively insoluble compounds within the fiber. Sulfur and vat dyes are 
insoluble and therefore must be chemically modified before coloring fiber. 
With these dyes, the insoluble dye is first reduced to the soluble leuco 
compound and after integration into fiber, oxidized back to the insoluble 
form using typically sodium sulfide for sulfur dyes and sodium perborate 
for vat dyes. 
Cellulose fibers may be dyed utilizing a variety of methods ranging from 
dyeing individual fibers to consolidated webs and by dyeing at points 
within the nonwoven web construction process. Exemplary methods include 
beater or stock coloring within the slush or slurry to dyeing webs by 
padding, jig dipping, dyebaths, squeezing, extraction operations, foam 
curtain dyeing and printing. Many of these methods are off-line textile 
finishing processes. 
Specialized pad-batch, pad-thermofix, and pad-steam methods and modified 
versions for continuous operations with numerous steps have also been 
developed for reactive dyes by padding the web with dye solution. The web 
is then either stored for extended reaction times in a vapor tight 
enclosure or steam heated, further padded, and afterwards the web is 
washed of spent chemical. 
Low speed continuous pad-jig methods and pad-steam methods are often 
employed for permanent dyeing of webs with vat dyes. Suitable reaction 
times have been achieved especially at elevated temperatures. After 
chemical dyeing using reactive and vat dyes, a washing step(s) is added to 
remove unreacted exhausted chemicals since the reaction is not 100% 
complete. More permanent colorants generally require several chemical 
process steps and extended reaction times. 
While reactive dyes, vat dyes and sulfur dyes appear desirable for use with 
cellulose fibers, application of these dyes requires more than one process 
step and is often hampered by slow line speeds needed to achieve adequate 
reaction times. 
Accordingly a need exists for a simple process for applying reactive dyes, 
vat dyes and sulfur dyes to cellulose fibers and to cellulose fiber 
containing nonwoven materials to produce durable coloration. This need 
extends to a continuous or one-step process for applying such dyes to the 
described substrates so they are colorfast. This need also extends to a 
process for applying such dyes that is suitable for high-speed 
manufacturing processes. There is also a need for colorfast cellulose 
fibers, nonwoven materials containing colorfast cellulose fibers, and 
colorfast nonwoven materials that include cellulose fibers that are 
prepared in a simple, one-step process. 
DEFINITIONS 
As used herein, the term "nonwoven web" refers to a web that has a 
structure of individual fibers or filaments which are interlaid, but not 
in an identifiable repeating manner. Nonwoven webs have been, in the past, 
formed by a variety of processes known to those skilled in the art such 
as, for example, meltblowing, spunbonding, wet-forming and various bonded 
carded web processes. 
The term "pulp" as used herein refers to cellulosic fibers from natural 
sources such as woody and non-woody plants. Woody plants include, for 
example, deciduous and coniferous trees. Non-woody plants include, for 
example, cotton, flax, esparto grass, milkweed, straw, jute hemp, and 
bagasse. 
The terms "colorfast" and/or "fastness" refer to the extent that color will 
fade or change upon exposure to an agent such as, for example, sunlight, 
reactive gases, chemicals, solvents and the like. Colorfastness or 
fastness can be measured by standard test methods such as, for example, 
AATCC Test Method 3-1989. 
The terms "crock" or "crockfast" refers to the extent that color may be 
transferred from the surface of a dyed fabric to another surface by 
rubbing. Crock testing may be carried out utilizing standard test 
procedures and equipment such as, for example, an AATCC Crockmeter Model 
CM.5, available from Atlas Electric Devices Co. Chicago, Ill. 
As used herein, the term "sheet" refers to a material that can be a woven 
fabric, knit fabric, nonwoven fabric or film-like material (e.g., an 
apertured film-like material). 
As used herein, the term "spunbonded filaments" refers to small diameter 
continuous filaments which are formed by extruding a molten thermoplastic 
material as filaments from a plurality of fine, usually circular, 
capillaries of a spinnerette with the diameter of the extruded filaments 
then being rapidly reduced as by, for example, eductive drawing and/or 
other well-known spunbonding mechanisms. The production of spun-bonded 
nonwoven webs is illustrated in patents such as, for example, in U.S. Pat. 
No. 4,340,563 to Appel et al., and U.S. Pat. No. 3,692,618 to Dorschner et 
al. The disclosures of these patents are hereby incorporated by reference. 
As used herein, the term "conjugate spun filaments" refers to spun 
filaments and/or fibers composed of multiple filamentary or fibril 
elements. Exemplary conjugate filaments may have a sheath/core 
configuration (i.e., a core portion substantially or completely enveloped 
by one or more sheaths) and/or side-by-side strands (i.e., filaments) 
configuration (i.e., multiple filaments/fibers attached along a common 
interface). Generally speaking, the different elements making up the 
conjugate filament (e.g., the core portion, the sheath portion, and/or the 
side-by-side filaments) are formed of different polymers and spun using 
processes such as, for example, melt-spinning processes, solvent spinning 
processes and the like. Desirably, the conjugate spun filaments are formed 
from thermoplastic polymers utilizing a melt-spinning process such as a 
spunbond process adapted to produce conjugate spunbond filaments. 
As used herein, the term "hydraulic entangling" refers to a method of 
mechanically bonding a fibrous material by treatment with pressurized jets 
of a liquid. Exemplary hydraulic entangling processes are disclosed at, 
for example, U.S. Pat. No. 3,485,706 to Evans et al.; U.S. Pat. No. 
4,939,016 to Radwanski et al.; and U.S. Pat. No. 5,389,202 to Everhart et 
al. 
As used herein, the term "hydraulic needling" refers to a method of 
loosening, opening up, rearranging and/or modifying a relatively compact 
network of fibrous material utilizing pressurized jets of a liquid. An 
exemplary hydraulic needling process is disclosed at, for example, U.S. 
Pat. No. 5,137,600 to Barnes et al. 
As used herein, the term "consisting essentially of" does not exclude the 
presence of additional materials which do not significantly affect the 
desired characteristics of a given composition or product. Exemplary 
materials of this sort would include, without limitation, pigments, 
antioxidants, stabilizers, surfactants, waxes, flow promoters, 
particulates or materials added to enhance processability of a 
composition. 
SUMMARY OF THE INVENTION 
The problems described above are addressed by the present invention which 
is directed to a process for treating a fibrous material. The process 
includes the steps of: 1) providing a liquid suspension composed of 
fibrous material; 2)intermixing the liquid suspension of fibrous material 
with a treatment over a time period T.sub.1 --wherein the treatment 
requires a period of time T.sub.R to treat the fibrous material; 3) 
depositing the liquid suspension of fibrous material and intermixed 
treatment onto a forming surface to form a layer and removing a 
substantial portion of the liquid, over a period of time T.sub.2 ; and 4) 
applying pressurized jets of a liquid to the layer of fibrous material to 
wash unused treatment from the fibrous material within a period of time 
T.sub.3. According to the invention, the periods of time T.sub.1, T.sub.2 
and T.sub.3 are immediately consecutive and amount to a total period of 
time at least as great as T.sub.R. 
The liquid suspension of fibrous material may be an aqueous suspension and 
may contain fibrous material such as, for example, polyester fibers and/or 
cellulose containing fibers. Desirably, the cellulosic fibers are hydrated 
cellulosic fibers. Generally speaking, the fibrous cellulosic material can 
be pulp fibers, synthetic cellulose fibers, modified cellulose fibers and 
combinations thereof. The fibrous cellulosic material may include 
particulates, non-cellulosic fibrous materials and/or other materials. 
According to the invention, the treatment is desirably a chemically 
reactive treatment. The chemically reactive treatment may be one or more 
of reactive dyes, vat dyes and sulfur dyes. 
In an aspect of the invention, the deposited layer of fibrous material and 
intermixed treatment may be formed into a web or sheet-like structure. 
This web may be smooth or may have patterns, striations, bumps, ridges or 
the like. 
The forming surface which receives the deposited layer may include at least 
one layer of sheet material between the forming surface and the deposited 
layer of fibrous material and intermixed treatment. This sheet material 
can be one or more nonwoven webs, textile webs, scrim materials, 
plexifilimentary films, tows and combinations of the same. For example, 
the nonwoven webs may be one or more meltblown webs, spunbond webs, bonded 
carded webs, fibrous batts, air-laid webs, wet-laid webs, coformed webs 
and combinations thereof. Additional layers of sheet material may be 
positioned over the deposited layer of fibrous material. According to an 
embodiment of the invention, the deposited layer of fibrous material may 
be sandwiched between two layers of sheet material. Alternatively and/or 
additionally, the web may be formed separately and then joined to another 
layer of material (e.g., a spunbond nonwoven web or the like) prior to 
treatment with pressurized jets of a liquid. 
According to the invention, the applied pressurized jets of liquid used to 
wash unused treatment from the fibrous material may also be sufficient to 
hydraulically entangle the fibrous material. Hydraulic entangling may be 
limited to only the fibrous material or may involve the fibrous material 
and one or more layers of sheet material described above. Alternatively 
and/or additionally, the applied pressurized jets of liquid used to wash 
unused treatment from the fibrous material may also be sufficient to 
hydraulically needle the fibrous material. Hydraulic needling may be 
limited to only the fibrous material or may involve the fibrous material 
and one or more layers of sheet material described above. 
The process of the present invention may include one or more (e.g., at 
least one) secondary or post treatment step(s). Exemplary post treatment 
steps include additional washing steps, drying steps, embossing steps, 
perforating steps, adding a fixative, curing agent, mechanical softening 
steps, slitting, winding and the like. 
The present invention encompasses a product produced by the process 
described above. The product is a web or sheet-like material composed of 
or including treated fibrous material. For example, the product may be a 
web composed of or including colorfast fibrous cellulosic material. 
In an aspect of the invention, T.sub.R may range from a few minutes to an 
hour or more. T.sub.1, T.sub.2 and T.sub.3 may each individually range 
from less than a second to several minutes to an hour or more as long as 
they are immediately consecutive (i.e., with no significant time gaps, 
down time or off-line time between at least T.sub.2 and T.sub.3) and 
amount to a total period of time at least as great as T.sub.R. 
In one embodiment, the present invention encompasses a process of forming a 
web of treated fibrous cellulosic material. The process includes the steps 
of: 1) providing an aqueous suspension including hydrated fibrous 
cellulosic material; 2) intermixing the aqueous suspension of hydrated 
fibrous cellulosic material with a reactive treatment over a time period 
T.sub.1, the treatment requiring a period of time T.sub.R sufficient to 
treat the fibrous cellulosic material; 3) depositing the aqueous 
suspension of hydrated fibrous cellulosic material and intermixed reactive 
treatment onto a surface to form a web and removing a substantial portion 
of the aqueous liquid, over a period of time T.sub.2 ; and 3) applying 
pressurized jets of a liquid to the web to wash unused reactive treatment 
from the web within a period of time T.sub.3 ; wherein T.sub.1, T.sub.2 
and T.sub.3 are immediately consecutive and amount to a period of time at 
least as great as T.sub.R. 
Desirably, the chemically reactive treatment is selected from reactive 
dyes, vat dyes and sulfur dyes. If a vat dye is used, the process is 
practiced such that the vat dye is reduced to its soluble leuco form and 
subsequently converted to an insoluble form during the period of time 
T.sub.R. 
The process may be practiced such that the forming surface includes at 
least one layer of sheet material between the forming surface and the 
deposited layer of fibrous material and intermixed treatment. 
Alternatively and/or additionally, the deposited layer of fibrous material 
may be formed separately and then joined to one or more layers of the same 
or another material (e.g., a spunbond nonwoven web or the like) prior to 
treatment with pressurized jets of a liquid. The fibrous cellulosic 
material may be one or more of pulp fibers, synthetic cellulose fibers and 
combinations thereof. 
According to the invention, the jets of a liquid may be adapted to 
hydraulically entangle the web. Alternatively, the jets of a liquid may be 
adapted to hydraulically needle the web. Of course, the process of present 
invention may further include at least one post treatment steps. 
Another embodiment of the invention encompasses a process for forming a web 
of colorfast fibrous cellulosic material. The process includes the steps 
of: 1) providing an aqueous suspension comprising hydrated fibrous 
cellulosic material; 2) intermixing the aqueous suspension of hydrated 
fibrous cellulosic material with a reactive treatment over a time period 
T.sub.1, said treatment selected from reactive dyes, vat dyes and sulfur 
dyes requiring a period of time T.sub.R sufficient to treat the fibrous 
cellulosic material; 3) depositing the aqueous suspension of hydrated 
fibrous cellulosic material and intermixed reactive treatment onto a 
surface to form a web and removing a substantial portion of the aqueous 
liquid, over a period of time T.sub.2 ; and 3) applying pressurized jets 
of a liquid to the web to wash unused reactive treatment from the web 
within a period of time T.sub.3 ; wherein T.sub.1, T.sub.2 and T.sub.3 are 
immediately consecutive and amount to a period of time at least as great 
as T.sub.R. 
If a vat dye is used, the process is practiced such that the vat dye is 
reduced to its soluble leuco form and subsequently converted to an 
insoluble form during the period of time T.sub.R. 
The forming surface may include a least one layer of sheet material between 
the forming surface and the deposited layer of fibrous cellulosic material 
and intermixed reactive treatment. Alternatively and/or additionally, the 
deposited layer of fibrous cellulosic material may be formed separately 
and then joined to one or more layers of the same or another material 
(e.g., a spunbond nonwoven web or the like) prior to treatment with 
pressurized jets of a liquid. The fibrous cellulosic material may be one 
or more of pulp fibers, synthetic cellulose fibers, modified cellulose 
fibers and combinations thereof. 
According to the invention, the pressurized jets of a liquid may be adapted 
to hydraulically entangle the web. Alternatively, the pressurized jets of 
a liquid may be adapted to hydraulically needle the web. Of course, the 
process of present invention may further include at least one post 
treatment step. 
The present invention also encompasses a hydraulically entangled structure 
composed of colorfast, fibrous material. The structure is composed of: 1) 
at least one layer a wet-laid nonwoven web containing fibrous cellulosic 
material; and 2) colorfast dye imparting color to the fibrous cellulosic 
material such that the fibrous cellulosic material is colorfast. 
The wet-laid nonwoven web component of the hydraulically entangled 
structure may include a layer of sheet material. The sheet material may be 
selected from spunbond webs, meltblown webs, bonded carded webs, woven 
fabrics, knit fabrics, scrims and combinations thereof. Alternatively 
and/or additionally, the hydraulically entangled structure of colorfast, 
fibrous material may include a matrix of adhesive material. The adhesive 
material may be a resin or glue. The colorfast dye component of the 
hydraulically entangled structure may be selected from reactive dyes, vat 
dyes and sulfur dyes. 
The present invention also encompasses a hydraulically needled structure 
composed of colorfast, fibrous material. The structure is composed of: 1) 
at least one layer a wet-laid nonwoven web containing fibrous cellulosic 
material; and 2) colorfast dye imparting color to the fibrous cellulosic 
material such that the fibrous cellulosic material is colorfast. The 
hydraulically needled structure of colorfast, fibrous material may include 
a matrix of adhesive material. The adhesive material may be a resin or 
glue. The colorfast dye component of the hydraulically needled structure 
may be selected from reactive dyes, vat dyes and sulfur dyes.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to FIG. 1, there is shown an illustration (not necessarily to 
scale) of an exemplary process for treating a fibrous material. Generally 
speaking, the treatment process may be incorporated into the fiber 
preparation stage of a high speed wet-laying web forming operation that is 
coupled with a pressurized liquid jet operation where unused or spent 
treatment and/or chemicals are washed from the fibrous material. For 
example, the treatment process can be incorporated into the pulping and 
stock preparation stage of a high-speed papermaking operation that is 
coupled with a hydraulic entangling or hydraulic needling operation where 
unused or spent treatment and/or chemicals are washed from the fibrous 
material. However, it should be understood that the present invention is 
not limited to such a configuration. 
According to an embodiment of the present invention, a fibrous material 10 
may be placed in a conventional papermaking fiber stock prep beater or 
pulper 12 containing a liquid (usually water). If the fibers are 
cellulosic in nature, the fibers may be refined in the beater or pulper 
until they are hydrated. The fibrous material stock is kept in continual 
agitation to form a liquid suspension. 
A treatment is added to the fibrous material in the pulper or beater 12. If 
the fibrous material is cellulosic, the treatment is desirably added after 
the fibers are hydrated. The treatment may be in solid, liquid or gaseous 
form or combinations thereof. For example, the treatment may be in the 
form of pellets that dissolve in the liquid medium used to suspend the 
fibrous material. Alternatively and/or additionally, the treatment may be 
in form of a liquid added to or a gas that is blown into the liquid 
medium. The treatment may be composed of one or more components, reactants 
and/or phases added to the fibrous material at the same or at different 
times. 
Generally speaking, the fibrous material is kept in continual agitation 
thus intermixing the liquid suspension of fibrous material and treatment. 
However, agitation may be stopped or used intermittently if excessive 
agitation would be harmful to the treatment or fibrous material. For 
example, agitation could be reduced if air entrained by agitation could 
oxidize or react with the treatment and reduce its effectiveness. 
After fiber treatment (e.g., dyeing) within the pulper or beater 12, the 
suspension of fibrous material and intermixed treatment (e.g., stock 
slurry)is then diluted and readied for formation into a layer of fibrous 
material or web utilizing conventional wet-laying or papermaking 
techniques. The stock slurry 14 may be stored in a machine chest 15 prior 
to web forming. If desired, the stock slurry pH may be adjusted for 
equipment compatibility 
Fixatives and additives may be added at the pulper, machine chest, or 
immediately prior to forming. These material may be added to improve 
fastness and other properties such as softness and wet-strength. If 
desired, additional fibrous materials may be added. These materials may 
have had the same or different treatment. For example, these additional 
materials may have the same color or a different color. Examples of 
fibrous materials that may be added include wood furnishes, other 
cellulosic fibers, synthetic non-cellulosic wet forming staple fibers and 
the like. 
These fibrous materials can be added to the stock slurry prior to forming 
the web to enhance strength, aesthetic, and durability properties. They 
can also be handled as separate slurry or slurries if one or more layers 
of different fiber types is desired. 
Although non-cellulosic fibrous material (e.g., staple fibers) can be 
treated or dyed in a separate process, it is contemplated that they could 
be treated or dyed within the same system as the cellulosic fibrous 
material. For example, certain conventional vat dyes may be used to dye 
polyester fibrous material using thermofixing. Staple synthetic 
non-cellulosic fibers include polypropylene, polyester, nylon and 
polyethylene fibers. 
The diluted aqueous suspension (e.g., stock slurry) 14 is conveyed and 
formed onto a moving foraminous forming wire 16 using a conventional 
papermaking headbox 18 or layering headbox with a forming section such as 
a Fourdrinier or incline wire. The incline wire generally being used to 
wet form relatively long fibers such as, for example, staple fibers. 
According to the present invention, high-speed papermaking machine web 
speeds of up to 2000 feet per minute (fpm) or more may be used. These 
speeds can be much greater than conventional continuous textile vat and 
reactive dye processes. Web speeds in such conventional textile process 
may reach up to 360 fpm utilizing improved festoon web pathways and 
washers. 
After the aqueous suspension (e.g., stock slurry) is formed into a web 20 
and sufficiently dewatered (typically at consistencies greater than 18%), 
pressurized jets of a liquid are applied to the web while it is on the 
forming fabric. Alternatively, the web may be transferred to a different 
moving fabric 22 or moving drum (not shown) where pressurized jets of a 
liquid are applied utilizing a pressurized liquid jet forming apparatus 
such as, for example, conventional hydraulic entangling equipment 24. 
Generally speaking, after treatments such as reactive or vat dyeing, the 
fibrous colored material must be washed to remove hydrolyzed and unfixed 
dye as well as spent chemicals. If this washing step is not done, fabric 
tendering, fastness, and color stability can be impaired. In addition, the 
washing step helps remove undesirable chemical residue that might present 
safety problems, problems for persons who have unprotected skin contact 
with the residue. Washing also helps minimize or eliminate undesirable 
wiping residue that could be caused by chemical left in the sheet. With 
most conventional textile fabric reactive and vat dye coloring systems, 
the washing step is necessary. A hot detergent bath is often used in the 
washing step of such conventional systems. However, these systems tend to 
be slow and are often performed in separate operations unconnected with 
the fabric forming process. 
According to the present invention, unused, excess or exhausted treatment 
(e.g., dye chemical) may be effectively removed from the web/fibrous 
material by using pressurized jets of a liquid such as, for example, 
hydraulic entangling jets. This can be attributed to the high velocities 
and high volumes of liquid (typically water) employed. Effective washing 
is also due to individual treated fibers being thoroughly washed with the 
first hydraulic entangling manifolds while fibers are still loose and 
mobile before becoming impacted and entangled within the web's fiber 
matrix. 
Warm soaps and detergents may be incorporated into the pressurized liquid 
jets used to wash the webs. However, the high shear and washing action of 
the jets may be adequate to remove unused treatments so that 
soap/detergent washing is not needed. Utilizing such high pressure jets of 
liquid immediately after the formation of the web from a liquid suspension 
to wash the web can eliminate additional washing steps. 
In an embodiment of the invention, hydraulic entangling or hydraulic 
needling steps are combined with the washing steps such that additional 
washing equipment and/or web consolidation equipment can be eliminated. 
For example, the pressurized jets of a liquid may be adapted to 
hydraulically entangle the web. The hydraulic entangling may be 
accomplished utilizing conventional hydraulic entangling equipment 24 such 
as may be found in, for example, in U.S. Pat. No. 3,485,706 to Evans, the 
disclosure of which is hereby incorporated by reference. The hydraulic 
entangling of the present invention may be carried out with any 
appropriate working fluid such as, for example, water. 
Alternatively, the pressurized jets of a liquid may be adapted to 
hydraulically needle the web. The hydraulic needling may be accomplished 
utilizing a process and equipment such as may be found in, for example, in 
U.S. Pat. No. 5,137,600, issued on Aug. 11, 1992, to Barnes et al., the 
disclosure of which is hereby incorporated by reference. The hydraulic 
needling of the present invention may be carried out with any appropriate 
working fluid such as, for example, water. 
Aqueous suspensions of fibrous material and intermixed treatment may also 
be wet formed onto a substrate material such as, for example, a nonwoven 
web. In some cases, the substrate material is surfactant treated and 
partitioned vacuum dewatering zones employed. Treated fibrous material 
(e.g., colorfast fibers) and a pre-formed nonwoven synthetic web can be 
treated with pressurized jets of a liquid (e.g., hydraulically entangled) 
on the forming wire or downstream on another wire section or perforated 
drum. 
Substrates such as, for example, woven and/or nonwoven webs 26 can also be 
readily added upstream of the hydraulic entangling equipment 24 after the 
layer of fibrous material or web 20 has been formed. Generally speaking, 
such techniques are disclosed in, for example, in U.S. Pat. No. 5,389,202 
issued on Feb. 14, 1995, to Everhart et al., the disclosure of which is 
hereby incorporated by reference. Other layers may be added on top of the 
fibrous layer 20 to form a multi-layered (e.g., three or more layered) 
web. A wide variety of substrates is contemplated. For example, if the 
substrate is a nonwoven web, it can include continuous filaments such as 
spunbond and netting, meltblown, coform admixtures, carded and air formed 
staple fiber webs and combinations thereof. Such webs can be made of 
elastic or non-elastic spun polymers. Fibers and/or filaments can be made 
of thermoset or thermoplastic polymers. 
Either one side or both sides of the materials may be treated with 
pressurized jets of a liquid. It is contemplated that the jets of liquid 
can be use to pattern the materials to produce cloth-like aesthetics using 
selective entangling backings. 
Discharged water from the first pressurized liquid jet (e.g., hydraulic 
entangling) manifolds can be isolated from downstream manifolds since they 
are richer in washed-off treatments such as, for example, exhausted dye 
chemicals. Exhausted chemical and water can be treated and either reused 
within the process or cascaded in other on-site papermachine processes 
which require less stringent water conditions. 
After the washing step, additional chemical and/or mechanical treatments 28 
can be applied. For example, further washing or application of liquid 
treatments can accomplished by using, sprays, dip and squeeze techniques, 
vacuum extraction processes liquid curtains or the like. An example of a 
suitable process for applying liquid is disclosed at, for example, U.S. 
Pat. No. 5,486,381, entitled "Liquid Saturation Process" and issued on 
Jan. 23, 1996, to Cleveland et al., the contents of which are incorporated 
herein by reference. 
Such equipment can also be used to add other types of chemicals or 
treatments including, for example, fixing agents. With the web washed of 
treatments such as, for example, exhausted dye, various fixing agents can 
be used at lower amounts than if introduced in the fiber stock prep stage 
(i.e., in the pulper or beater 12) to better fix the treatment since 
fugitive treatment has been washed from the fabric. For example, less dye 
fixing chemical may be required to fix dye molecules diffused into or 
bonded to individual fibers since excess or fugitive dye has been washed 
from the surface and interstices of the fibrous material. 
Other chemicals can also be added including wet-strength resins, binders, 
brighteners, flame retardants, germicides, softeners, starches, corrosion 
inhibitors and a wide range of textile finishes. Citric acid and ethylene 
diamine can also be added to improve colorant fastness properties. 
The treated and washed material may be dried. Through-air drying processes 
and can drying processes 30 have been found to work well. Other drying 
processes which incorporate infra-red radiation, yankee dryers, vacuum 
de-watering, microwaves, and ultrasonic energy may also be used. Thermal 
post-treatments may be used alone or in combination with the drying step 
to fuse a portion of any thermally fusable fibers that may be present in 
the material. 
It may be desirable to use finishing steps and/or post treatment processes 
to impart selected properties to the material. For example, the material 
may be lightly pressed by calender rolls, creped or brushed to provide a 
uniform exterior appearance and/or certain tactile properties. 
Alternatively and/or additionally, chemical post-treatments such as, 
adhesives or dyes may be added to the fabric. 
The material may also be wet or dry creped and/or mechanically softened via 
other methods to improve softness and hand or adhesive recreped to improve 
strength and bulk properties. Printed finishes may also be applied to 
improve aesthetics. Such processes can be inline prior to winding up the 
fabric onto a roll 32 or off-line. 
A variety of fibrous materials may be used in the present invention. 
Generally speaking, the fibrous material should be able to withstand 
potentially aggressive or deleterious treatments such as, for example, 
reactive treatments or treatments requiring a relatively long exposure or 
residence time. Some fibers that may be used include, but are not limited 
to, pulp, cellulosic fibers including natural, synthetic and modified 
cellulose fibers, and polyester fibers, and combinations thereof. 
Cellulose fiber sources for treatment (e.g., dyeing) include virgin wood 
fibers such as thermomechanical, bleached and unbleached softwood and 
hardwood pulps. Secondary or recycled fibers may be used. These fibers may 
be obtained from sources such as office waste, newsprint, brown paper 
stock, and paperboard scrap. Vegetable fibers can be used. These include 
hemp, abaca, flax, milkweed, cotton, modified cotton, and cotton linters. 
Synthetic cellulosic fibers such as, for example, rayon and viscose rayon 
may also be used. Another exemplary type of synthetic cellulose is 
available under the trade designation "Lyocell" from Cortaulds. Modified 
cellulose fiber may also be used. For example, the fibrous material may be 
composed of derivatives of cellulose formed by substitution of appropriate 
radicals (e.g., carboxyl, alkyl, acetate, nitrate, etc.) for hydroxyl 
groups along the carbon chain. These fibers may be used alone, in 
combination with other cellulosic fibers and/or non-cellulosic fibers. 
Particulates and/or other materials may also be used with the fibrous 
materials. 
When wood pulp (e.g., wood fibers) are used, stock consistencies of up to 
about 12% can readily be treated (e.g., dyed). After cellulosic fibers are 
fully hydrated, loose, and the fiber lumen swollen for accessibility, 
impregnation of a treatment (e.g., dye molecule) within the fiber 
structure is more fully and effectively accomplished. Less treatment 
(e.g., less dye) may be used under these conditions in comparison to 
conventional web treatments (e.g., web dyeing). Additional benefits may be 
realized if the treatment is a dye treatment. For example, in situations 
where excess dye is used to obtain deep levels of color, better 
incorporation of dye within the fiber produces better colorfastness. 
Although the inventors should not be held to a particular theory of 
operation, the process of the present invention intermixes individual, 
agitated and freely suspended fibers with a treatment (e.g., a dye 
treatment). It is thought that more effective and thorough coloring may be 
obtained since migration of dye treatment/chemical into individual fibers 
is not impaired. 
In contrast, fibers already fixed and embedded within a consolidated web 
are thought to impede migration of dye treatment/chemical into individual 
fibers. In addition, many treatments and dyes have strong affinity for 
cellulose which may make uniform penetration into fibers already fixed and 
embedded in consolidated webs rather difficult. The process of the present 
invention is thought to provide more uniform application of treatment than 
many conventional methods such as, for example, padding methods. 
The fiber stock preparation step of the present invention allows control of 
long reaction times that may be needed for some treatments (e.g., to 
properly fix dye treatments) For example, reaction times typically greater 
than 60 seconds and often an hour or longer, may be realized. According to 
the present invention, temperature of the liquid suspension of fibrous 
material and intermixed treatment can also be controlled to facilitate 
optimum reaction kinetics. 
The present invention contemplates a variety of treatments to fibrous 
materials. The treatments may interact with the fibrous material in many 
ways including, but not limited to, coating, reacting, diffusing and 
fixing. Multicomponent treatments may be used. Treatments having several 
different reactants may also be used. In an aspect of the invention, the 
treatments will react with the surface of the fibrous material. In another 
aspect of the invention, the treatments may diffuse into the fibrous 
material and react with the fibrous material. In yet another aspect of the 
invention, the treatment may diffuse into the fibrous material or coat the 
surface of the fibrous material and then react with another component or 
agent of the treatment to fix the treatment in the fibrous material or on 
the fibrous material. 
Exemplary treatments include acid treatments, caustic or base treatments, 
single and multicomponent reactants, reactive dyes and the like may be 
used, either alone or in combination. Certain types of dye treatments have 
been found to work well in the process of the present invention. For 
example, the process of the present invention may be used to dye fibrous 
material using reactive dyes, vat dyes or sulfur dyes. 
Desirable treatments include reactive dyes. Generally speaking, these dyes 
are used with fibrous cellulosic materials. Although the inventors should 
not be held to a particular theory of operation, such dyes are generally 
thought to covalently bond to fiber. Reactive functional groups in the 
dyes are typically designed to react with cellulosic fiber often and 
preferably after diffusing into the fiber structure. These functional 
groups are designed to remain stable in and not react with the medium used 
for applying the dye. It is desirable that such dyes be able to function 
when water is used as the medium for applying the dye. Functional groups 
of these dyes may react with hydroxyl groups of cellulose to form 
cellulose ester fiber-dye covalent bonds that provide durable color. 
Water hardness may require adjustment when these dyes are used in aqueous 
fiber handling systems. The level of adjustment may be readily determined 
by one of ordinary skill in the art. Reactive dyes are generally added to 
cellulosic fibers in the beater or pulper after hydration. An electrolyte 
salt such as, for example, magnesium sulfate or sodium chloride may be 
added. Generally speaking, the pH of the liquid suspension of fibers and 
intermixed reactive dye is raised to alkali levels to enhance reactivity 
between the dye and the fibers. For example, the pH may be raised to about 
11 or 12. Alkali material such as, for example, soda ash (sodium 
hydroxide) or sodium bicarbonate may be used. Temperatures of the mixture 
of dye and fiber may be increased and held at elevated levels. Overall 
reaction time or period of time needed to adequately treat/dye the fiber 
(T.sub.R) may range from less than 60 seconds to more than 120 minutes. 
Exemplary reactive dyes include Procion.RTM. H and M series (ICI Americas 
Inc.) and Cibacron.RTM. series (Ciba-Geigy). These dyes have desirable 
levels of solubility in water. 
Reactive dyes have good light and wet fastness yet lack in bleachfastness. 
With use of secondary treatments after dyeing such as the use of urea, 
cationic fixing agents, and resins, modest improvements can be made. For 
many applications needing more stringent fastness requirements, vat dyes 
may be utilized. 
When used with cellulosic fibrous material, vat dyes may be added to the 
beater or pulper after the fibrous material is hydrated. When aqueous 
suspensions of fibers are employed, vat dyes are typically water insoluble 
and must first be reduced to produce a water soluble form. This can be 
accomplished in the beater or pulper at conventional conditions. For 
example, consistencies of up to 12% may be used. Water hardness may be 
adjusted to improve water solubility of the vat dye. Sodium sulfate may be 
added to facilitate dye impregnation into cellulose fibers. The presence 
of calcium, magnesium, aluminum and similar polyvalent ions can negatively 
effect the solubility of a vat dye. 
Generally speaking, vat dyes are converted from a water-insoluble form to a 
water-soluble "colorless" sodium-leuco form. This may be accomplished by 
adding an aqueous alkali solution of caustic soda (sodium hydroxide) and a 
reducing agent sodium hydrosulfite (sodium dithionite). The specific 
chemistry may vary with particular vat dyes but carrying out this step may 
be accomplished by one of ordinary skill in the art of vat dyeing. 
After the vat dye is solubilized, the sodium-leuco form has good affinity 
for cellulose fibers and thus impregnates the fiber structure. If not in 
this form, there is little to no impregnation into fiber. Vat dyes tend to 
impregnate fiber less than other dyes so care must be taken in application 
to produce good fastness. Consistency of the fiber suspension, agitation, 
and dye, chemical, electrolyte concentrations and addition rates are 
variables that may require adjustment. Such adjustments can be made by one 
of ordinary skill in the art of vat dyeing. Improper addition can produce 
uneven coloring. If impregnation into fiber does not properly occur, when 
the leuco form is oxidized back to the insoluble pigment, the vat dye will 
simply wash out. Typical period of time or reaction times (T.sub.R) for 
good dye impregnation and exhaustion in embodiments of the present 
invention are about 30-45 minutes. In some embodiments of the present 
invention, the time needed (T.sub.R) for adequate treatment may be even 
shorter. For example, adequate treatment may be carried out over a time 
period of 10 minutes. 
The water-soluble form of the vat dye which is impregnated in the fiber is 
then oxidized back to the water-insoluble form. This oxidation step is 
also a component of the period of time or reaction time (T.sub.R) needed 
to treat the fibrous material. The oxidation reaction normally occurs 
simply by exposing the impregnated fiber to air and with continued 
agitation. Materials such as, for example, sodium perborate, sodium 
bichromate, and/or sodium or calcium hypochlorite may be added to reduce 
the oxidation reaction time. In some cases, an acid may be added to 
achieve high levels of oxidation. 
Vat dyes may be classified into two categories: anthraquinonoid and 
indigoid dyes. Both may be used in the practice of the present invention. 
Examples of anthraquinonoid dyes include Cibanone.RTM. Dyes (Ciba-Geigy), 
Sandothrene.RTM. Dyes (Sandoz), and Caledon.RTM. Dyes (ICI). Indigoid dyes 
include Durindone.RTM. Dyes (ICI) and Ciba Blue 2B (Ciba-Geigy). Stable 
water soluble sulfate esters of leuco vat dyes may also be used. 
EXAMPLES 1-15 
Different reactive dyes, vat dyes and direct dyes were used to treat wood 
fibers. The dyes were used alone or in combination with fixative 
treatments. The dyes and fixative are available from the Ciba-Geigy 
Corporation, Basel, Switzerland. Specific Cibanone.RTM. series vat dyes, 
Cibacron.RTM. series reactive dyes, Pergasol.RTM. series cationic direct 
dyes and Tinofix.RTM. NF liquid fixative used in the examples are 
identified in Table 1. 
Wood fiber furnish utilized for the dyeing studies was Terrace Bay Longlac 
19, a bleached Northern softwood kraft pulp available from Kimberly-Clark 
Corporation, Roswell, Ga. 
Percentage amounts of formulations or recipes for vat dyes, reactive dyes 
and fixative treatments are based on pounds of ingredient per ton of wood 
fiber (i.e., lbs. of ingredient/2000 lbs. of wood fiber) where the wood 
fiber has an estimated 7% moisture content. The percentage amounts for 
other materials added are based on grams of ingredient per 100 grams of 
wood fiber or other furnish (i.e., gms. of ingredient/100 gms. wood fiber 
or other furnish). Reactions were typically carried out at ambient 
temperatures, under agitation, and water hardness was adjusted to 
approximately 100 PPM prior to dye addition unless noted. The specific 
amounts of material used in the formulations or recipes are identified for 
each example in Table 1. 
GENERAL PROCEDURE--VAT DYE 
The wood fiber furnish was soaked in tap water to full hydration and puiped 
at approximately 3 percent consistency utilizing a laboratory blender. A 
caustic solution (e.g., NaOH solution) was added to the wood furnish. In 
general, sufficient caustic solution was added to adjust the pH to about 
12. An electrolyte salt (e.g., sodium sulfate) was also added. The amount 
of electrolyte salt is listed in Table 1 for each example as a percentage 
based on pounds of ingredient per ton of wood fiber (i.e., lbs. of 
ingredient/2000 lbs. of wood fiber) where the wood fiber has an estimated 
7% moisture content. 
A vat dye was added to the wood furnish along with a reducing agent (e.g., 
sodium hydrosulfite) and agitated for a period of time. The amount is 
listed in Table 1 for each example as a percentage. Reaction time after 
the dye was added is listed in Table 1 for each example. 
After a specified period of time in which the vat dye impregnated the 
hydrated cellulose, an oxidizing agent (e.g., sodium perborate) was added 
to the mixture under agitation. The amount is listed Table 1 for each 
example as a percentage. The agitation time after addition of the 
oxidizing agent is also listed in Table 1 for each example. After 
agitation, the mixture was immediately transferred to a stock chest where 
it was diluted to a consistency appropriate for conventional handsheet 
formation. The handsheets were washed and formed utilizing a conventional 
handsheet former and then hydraulically entangled. 
GENERAL PROCEDURE--HYDRAULIC ENTANGLING 
The wet-formed (wet-laid) web of dyed wood pulp was positioned on top of a 
relatively low basis weight, conventional polypropylene spunbond web. The 
basis weight of the spunbond web was approximately 17 gsm (.about.0.5 osy) 
and the basis weight of wet-formed treated pulp web was approximately 73 
gsm (.about.2.2 osy) as determined from samples that were oven dried. 
A conventional hydraulic entangling system composed of 3 manifolds was 
used. The basic operating procedure is described at, for example, U.S. 
Pat. No. 5,389,202, issued Feb. 14, 1995, to Everhart et al., the contents 
of which are incorporated herein by reference. Each manifold had an 
orifice size of 0.006 inch diameter. Orifices were positioned in a single 
row at a spacing of about 40 orifices per linear inch of manifold. 
Manifold water pressure was 850 psig which generated high energy fine 
columnar jets. The hydraulic entangling surface was a single layer 103AM 
polyester wire backing manufactured by Albany International, Portland, 
Tenn. The wood pulp and spunbonded webs were passed under the manifolds at 
a line speed of about 20 feet per minute (fpm) where they were washed and 
consolidated by the pressurized jets of water. The resulting composite 
material was dried utilizing a conventional laboratory handsheet dryer. 
GENERAL PROCEDURE--DIRECT DYE 
A Pergasol Blue F3R solution was used to treat a hydraulically entangled 
wood/polypropylene spunbond substrate available as WORKHORSE.RTM. 
Manufactured Rags from Kimberly-Clark Corporation, Roswell, Ga. The wood 
fiber furnish employed is about 50% Longlac 19, 25% bleached Southern 
softwood kraft and 25% secondary fiber. The Pergasol Blue F3R solution was 
applied to the substrate utilizing a liquid weir arrangement as described 
in U.S. Pat. No. 5,486,381, entitled "Liquid Saturation Process" and 
issued on Jan. 23, 1996, to Cleveland et al., previously incorporated by 
reference. 
SAMPLE TESTING 
Substrate color levels were measured and recorded in Table 2 in CIELAB 
coordinates using a Hunter Lab Color Difference Meter, Model D25 Optical 
Sensor and manufactured by Hunter Associates Laboratory, Reston, Va. 
CIELAB coordinates are a system agreed upon in 1976 within the "Commission 
Internationale de l'Eclairage" or CIE. The coordinates are designated L*, 
a*, b*. The system uses a three axis opponent color scale assuming color 
is perceived in white to black (L*) or "lightness", green to red (a*), and 
yellow to blue (b*) sensations. L* varies from 100 for a perfect white to 
zero for a perfect black. a* measures redness when plus (i.e., positive), 
grey when zero, and greenness when minus (i.e., negative). b* measures 
yellowness when plus (i.e., positive), grey when zero, and blueness when 
minus (i.e., negative). 
The CIELAB "Before Hydraulic Entangling Treatment (Before HET)" 
measurements were made using handsheets of the dyed wood furnish. "After 
Hydraulic Entangling Treatment (After HET)" measurements were made with 
the pulp side acting as the reflecting surface. The hydraulically 
entangled substrate contained white pigmented polypropylene spunbond 
fibrous web. The present invention is not limited to conventional 
hydraulic entangling treatment as a means to supply the pressurized jets 
of liquid to wash the fibrous material. It should be understood that 
hydraulic entangling treatment is an example of a type of pressurized 
liquid jet treatment that may be used. 
Colorfastness or "fastness" of the materials produced in the Examples was 
tested to measured tendency of the color to fade or change upon exposure 
to bleach, vinegar, Formula 409 and an industrial solvent. These tests 
were conducted generally in accordance with AATCC Test Method 3-1989 and 
the I.S.O. Recommendation (International Organization for Standardization) 
as described in Trotman, E. R., Dyeing and Chemical Technology of Textile 
Fibres, 5th Edition, Charles Griffen & Co. Limited, Whitstable, Kent, 
England, 1975. A rating of "1-5" color change grading scale was used with 
"5" being the highest rating with negligible or no color change to "1" 
being the lowest for large color change. 
In each case, a test sample of approximately 1 sq.inch in size was soaked 
for a specified time in 100 mL of test solution/solvent and then dried at 
ambient conditions overnight. Test samples were compared to control 
samples. 
Colorfastness upon exposure to household bleach (5.25% sodium hypochlorite) 
was studied at sarious concentrations of bleach. Test samples were soaked 
for 60 minutes with intermittent gentle agitation. 
Distillate household vinegar (5% acidity) and Formula 409 (The Clorox 
Company, Oakland, Calif.) were used separately on samples to study 
colorfastness. Samples were soaked for 5 minutes in vinegar or Formula 409 
without dilution. 
Colorfastness upon exposure to an industrial solvent was studied using 
Autowash 6000--a printer's solvent available from Printers' Service, 
Newark, N.J. Autowash 6000 is composed of aliphatic and aromatic petroleum 
distillates and ethyleneoxy ethanol. Samples were soaked 5 minutes. The 
results of these tests are reported in Table 3. 
Crock testing of substrates was performed on samples in both the dry state 
(See Table 2) and in the wet state (See Table 3) immediately after soaking 
in bleach, vinegar, Formula 409 or Autowash 6000 for the time specified 
above. The crock test determines the extent to which color may be 
transferred from the surface of a dyed fabric to another surface by 
rubbing (either while dry or while wetted with a specific liquid). 
Testing was conducted utilizing an AATCC Crockmeter Model CM.5 manufactured 
by Atlas Electric Devices Co., Chicago, Ill. Each sample was approximately 
4" wide.times.51/2" long and was oriented along machine direction (i.e., 
along the direction of web formation) when mounted in the tester. A small 
cotton square cloth (2.times.2 Crockmeter squares, Part #12-2592-0000, 
Test Fabrics Inc., Middlesex, N.J.) was mounted on the peg of the crock 
tester. Tests were conducted for 30 cycles utilized (unless fabric damage 
occurred) and each sample was rated using the AATCC Chromatic Transference 
Scale, 1994 Edition, American Association of Textile Chemists and 
Colorists, Research Triangle Park, N.C. Grading was based on a "1-5" scale 
with "5" indicating no color transfer, "4" indicating pale color transfer, 
"3" indicating some color transfer, "2" indicating lots of color transfer 
and "1" indicating large color transfer. A rating of "3" or greater is 
considered acceptable for most applications. 
RESULTS FOR EXAMPLES 1-15 
As shown in Table 2, only a small amount of color loss (if any) was 
measured when dyed wood fibers were subjected to the high velocity 
hydraulic entangling jets which indicates sufficient fiber substantivity. 
This is observed by comparing CIELAB coordinates L*, a*, b* values "Before 
HET" to the "After HET" values. Color differences can be attributed in 
part to loss of unbonded and unreacted dye chemical, fine fiber loss 
through the hydraulic entangling wire backing and added white spunbond 
fibers/filaments causing lightening of the consolidated substrate. 
A conventional spunbond polypropylene nonwoven web having a basis weight of 
about 17 gsm (about 0.5 osy) and identified as Example 15 served as a 
control material. Color measurement values are given as a reference for 
evaluating lightening of shade contribution due to white pigment added to 
the polypropylene used in manufacturing the spunbond nonwoven web. Similar 
polypropylene spunbond nonwoven web was hydraulically entangled with the 
treated (i.e., dyed) wood fibers as described above for Examples 1-13. The 
WORKHORSE.RTM. Manufactured Rag material of Example 14 also contained 
essentially identical polypropylene spunbond nonwoven web. 
Table 2 shows that the samples had acceptable dry crock results. As can be 
seen in Table 3, some dyes have better chemical fastness to certain 
chemicals and not to others and rarely are equally fast to all. Examples 1 
and 2 both have excellent colorfastness. Cibanone.RTM. Yellow 2G is 
included as a generally highly chemical fast colorant. 
Different amounts of other vat dyes which might be less colorfast can be 
added as toners for different color shades of a highly fast colorant. In 
this way, overall fastness can be retained as shown by Example 3 where a 
pizza or salmon color is based on a highly fast yellow color. 
As seen in the green shade Example 4, higher bleach concentrations (sodium 
hypochlorite) can negatively affect fastness. Addition of modest amounts 
of a fixing agent, Tinofix NF, to the stock prep vat dyeing process and a 
longer reaction time did not improve fastness nor crock resistance when 
comparing Examples 4 and 5. Adding fixing agents after the hydraulic 
entangling stage rather than during stock prep is expected to improve 
crock resistance. 
Vat dyes similar in color can have improved fastness as can be seen, for 
example, in Example 6. 
Blue vat colorants are difficult to make bleachfast (i.e., colorfast to 
bleach). Utilizing high levels of a fixing agent in the stock prep dyeing 
stage only modestly improved fastness as can be seen in a comparison of 
Examples 7, 8 and 9. By utilizing a combination of different colorfast vat 
dyes, a colorfast system could be produced. This is shown by combining 
Cibanone.RTM. Violet BNA DP (Example 10) and Cibanone.RTM. Olive B DP 
(Example 6) to produce a light blue which has improved fastness (Example 
11) over Examples 7, 8 and 9 which are composed of only one type of vat 
colorant. A deep shade of blue could be obtained with vat dyes with 
reasonable fastness as shown in Example 12. 
As seen in shown Example 13, the blue reactive dye overall colorant 
fastness was not as good as the vat dyes. For many applications, such 
fastness is acceptable. 
Pergasol.RTM. Blue F 3R, a cationic direct dye, is part of a family of dyes 
which are commonly used in the paper industry for many applications. Such 
dyes fall short in many durable applications requiring high chemical 
resistance. Though Pergosal.RTM. Blue F 3R is highly fast to water at the 
given add-on levels of Example 14, it is highly sensitive to bleach and 
other chemicals as shown in Table 1. 
EXAMPLE 16-29 
GENERAL PROCEDURE--VAT DYE 
Wood pulp was treated generally in accordance with the procedure used for 
Examples 1-15. The wood fiber furnish was pulped at consistency noted for 
each example in fresh water or white water from previous runs utilizing a 
Voith Slushmaker Repulper. Certain conditions for each example are noted 
below and in Table 4. The general conditions used for Examples 1-15 
including additional details provided in Examples 16 and 17 as well as 
Table 4 apply to the remaining Examples 18-29 except as given in the 
abbreviated notes below. 
EXAMPLES 16 and 17 PIZZA/SALMON -1 
Step 1. 60 lbs.--Terrace Bay LL19 pulped at a 3.3% consistency (fresh 
water) using a Voith Slushmaker Repulper. 
Step 2. 3 L NaOH (50% soln.)--agitate 30 sec. 
Step 3. 20% Sodium Sulfate--(by wt., 400 lbs./ton) .about.5446 grams. 
Continue agitation. 
Step 4. Add Vat Dyes--Cibanone.RTM. Yellow 2G PST--(40 lbs./ton) .about.545 
gm and Cibanone.RTM. Red 6B PST, (101 lbs./ton) .about.136 gm. Continue 
agitation. 
Step 5. 10% Sodium Hydrosulfite (by wt.) .about.2724 gm. pH=12.3. Agitated 
2 mins. and stopped pulper. Remeasured pH=13.5. Color change occurred with 
reduction of dye. 
Step 6. 40 mins. total reaction time with 30 secs. of agitation after 15 
mins. of reaction, again repeated a second time. During the interim, the 
pulper was stopped. 
Step 7. After 40 mins. pulper restarted, 7.5%, Sodium Perborate added (by 
wt.) .about.2043 gm. and pulper ran 20 mins. before dumping into stock 
chest for forming. 
Step 8. Of the 60 lbs. of dyed stock, the tank was filled to the 103" mark 
(2880 gals.) (0.23 consistency) and then discharged, and diluted to a 
0.17% consistency. This consistency was then utilized to form a web or 
layer of treated wood fibers. 
Results: Crock testing results ranged from Ratings of "3" to "5" and are 
acceptable. See Table 5, Examples 16A through 17B. When the furnish is 
sandwiched between nonwoven spunbond webs, crock fastness improves. 
The leucoform of the vat dye is a dark-colored purple shade. Tinofix.RTM. 
NF (a fixing agent) was added to the pressure jet treated material using a 
weir fluid distributor of the type described at, for example in U.S. Pat. 
No. 5,486,381, previously incorporated by reference. No improvement in 
fastness was noted. 
EXAMPLES 18 and 19 PIZZA/SALMON-2 
Refer to Example 16 for General Dyeing Procedure. Changes are noted in 
specific Steps. 
Step 1. Part of pulping water was make-up white water from Example 16. 
Step 2. 1 L NaOH (50% soln.) added. Lowered pH with hydrochloric and 
sulfuric acid. Remeasured pH=13.3. 
Step 4. Add Cibanone.RTM. Yellow 2G PST--(60 lbs./ton), 717 gm @ 0 reaction 
time. Cibanone.RTM. Red 6B PST--(15 lbs./ton).about.204 gm. 
After 25 mins. of reaction, another 100 gms. of Cibanone.RTM. Yellow 2G was 
added and the reaction time was increased an additional 10 mins. for a 
total time of 50 mins. 
Results: See Table 5. 
EXAMPLES 20 and 21--PIZZA/SALMON-4 
Step 1. White water from prior run was used for repulping. 
Step 2. 185 mL. NaOH (50% soln.). pH=12.5. 
Step 3. 25% Sodium Sulfate (by wt.)--6810 gm. 
Step 4. Add Cibanone.RTM. Yellow 2G PST (80 lbs./t)--1090 gm and 
Cibanone.RTM. Red 6B PST (20 lbs./t)--272 gms. 
Results: See Table 5. 
EXAMPLES 22 and 23--ORANGE-1 
Step 1. Fresh water. 50:50 LL19/SSWK. (i.e., a fiber lend of equal parts 
LL19 Northern softwood kraft pulp and Southern softwood kraft pulp (SSWK)) 
60 lbs. pulped 10 mins. @ 3.3% consistency. 
Step 2. 3.5 L NaOH (50% soln.), pH =12.2 
Step 3. 25% Sodium Sulfate--6810 gm. 
Step 4. Add Cibanone.RTM. Orange 5G DP (33 lbs./t)--450 gm. and 
Cibanone.RTM. Red 2B PST (54 lbs./t)--735 gm. 
Step 7. After 40 min reaction time, the pulper slurry was agitated 5 mins. 
to see if there was sufficient selfoxidation. Because of insufficient 
oxidation (no color change), 7.5% sodium perborate (2043 g) was added. 
Results: The leucoform is a dark chocolate color. Furnish color level was 
acceptable. Crock fastness for the sandwiched fabric was acceptable with 
Ratings of 4 to 5. See Table 5. 
EXAMPLES 24 and 25 BLUE-GRAY-1 (WSK-21) 
Step 1. Fresh water. 60 lbs. of a 50:50 LL19/SSWK furnish. 
Step 2. 2.5 L NaOH (50% soln.). pH=12.2. 
Step 3. 25% Sodium Sulfate--6810 g. 
Step 4. Add Cibanone.RTM. Orange 5G DP--136 g (10 lbs./ton), Cibanone.RTM. 
Navy PS PST--817 g (60 lbs./ton) and Cibanone.RTM. Blue GFJ DP--272 g (20 
lbs./ton). 
Results: See Table 5. 
EXAMPLES 26, 27 and 28--BLUE-GRAY-2 
Step 1. Fresh water. 60 lbs. of 50:50 LL19/SSWK furnish. 
Step 2. 2.5 L NaOH (50% soln.), pH=12.3. 
Step 3. Cibanone.RTM. Orange 5G DP--82 g (6 lbs./ton), Cibanone.RTM. Navy 
PS PST--409 g (30 lbs./ton) and Cibanone.RTM. Blue GFJ DP--136 g (10 
lbs./ton). 
Results: Poor Crock and colorfastness results as shown in Table 5. A shift 
in color took place when the material was exposed to Formula 409. 
EXAMPLE 29--LIGHT BLUE (WSK-9) 
Step 1. 60 lbs. furnish, 50:50 LL19/SSWK. Fresh water. 
Step 2. 2.5 L NaOH (50% soln.) pH=12.3. 
Step 3. 25% Sodium Sulfate--6810 g. 
Step 4. Add Cibanone.RTM. Navy PS PST--68 g (5 lbs./ton) and Cibanone.RTM. 
Blue GFJ DP--109 g (8 lbs./ton) 
Results: See Table 5. 
pH and Sulfate Testing 
Materials from Examples 20-29 were cut into 10 inch by 10 inch square 
samples. Individual samples were soaked for 30 minutes in 200 mL of tap 
water at ambient temperature. After soaking, each sample was squeezed and 
rinsed with soak water through a wash ringer five times. The liquid in 
which an individual sample was soaked and the liquid squeezed from that 
sample was combined. 
The pH of the liquid was measured with a conventional pH tester and the 
results are listed in Table 5. Sulfate levels in the liquid were tested 
utilizing a Hach DR/2000 Direct Reading Spectrophotomer and the Hach 
Sulfaver 4 Method (Turbidity Method). The results of the sulfate testing 
are reported in Table 5 in units of mg/L. As shown in Table 5, the pH 
levels were at or near neutral and the sulfate levels were between zero 
and about 3 mg/L indicating effective washing with the hydraulic 
entangling jets. 
While the present invention has been described in connection with certain 
embodiments, it is to be understood that the subject matter encompassed by 
way of the present invention is not to be limited to those specific 
embodiments. On the contrary, it is intended for the subject matter of the 
invention to include all alternatives, modifications and equivalents as 
can be included within the spirit and scope of the following claims. 
TABLE 1 
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DYE 
EXAMPLE