US20030176136A1

US20030176136A1 - Biodegradable cotton composites

Info

Publication number: US20030176136A1
Application number: US10/339,129
Authority: US
Inventors: Larry Wadsworth
Original assignee: Individual
Current assignee: University of Tennessee Research Foundation
Priority date: 2002-01-10
Filing date: 2003-01-09
Publication date: 2003-09-18
Also published as: AU2003202935A1; WO2003059621A1

Abstract

A non-woven composite is disclosed, comprising a first layer, further comprising a biodegradable component; and a second layer, further comprising a biodegradation enhancement component, the second layer being bonded to the first layer. As each of these two layers has a biodegradable component, overall biodegrading is enhanced. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Description

PRIORITY DATA

This application claims benefit under 35 U.S.C. Section 119 of provisional application 60/348,033 filed Jan. 10, 2002.[0001]

FIELD OF THE INVENTION

The present invention relates generally to the field of composite materials and in particular non-woven fabrics which contain biodegradable material such as cotton.

BACKGROUND OF THE INVENTION

Cellulosic fibers offer the advantage of biodegradability of that component of the composite and render the composite more comfortable for wear and more useful in hygienic personal care products due to enhanced liquid absorption. The cotton-core and cotton-surfaced composites of this invention have been further enhanced by imparting elasticity, by incorporating more biodegradable components in addition to cellulosic fibers and by the addition of wetting agents to improve the wetting properties and accessibility for enhanced biodegradability.

Thermally bonded non-woven laminates with spunbond polypropylene on one side and a meltblown polypropylene web on the other side have been shown to have greater wicking rate, water absorptive capacity, and water retention capacity than a similar construction with light weight meltblown polypropylene webs on both sides. An example of such a laminate is disclosed in U.S. Pat. No. 5,683,794.

Inherent properties of fibers that can be produced from different biodegradable polymers may be a factor in engineering structures to produce the laminate with the required mechanical strength, flexibility, barrier, filtration, absorbency properties and other traits. For example, spunbond and meltblown non-woven fabrics and staple fibers made from poly(lactide). Poly(lactide) has tenacity and elongation-to-break properties similar to more conventional polypropylene fibers and fabric. In fact, poly(lactide) staple fibers can be readily processed through a carding machine as 100% poly(lactide) or in blends with other fibers such as cotton or rayon. However, the poly(lactide) fibers and fabrics are more difficult to thermally bond by hot air, heated calenders, ultrasonic and infrared bonding than polypropylene or other material.

A problem with many laminates is that only portions of the laminate are fully biodegradable, leaving other portions either partially or non-biodegradable.

SUMMARY OF THE INVENTION

A non-woven composite having increased biodegradation properties is disclosed and may be produced by creating a first layer, the first layer comprising a first biodegradable component; creating a second layer, the second layer comprising a biodegradation enhancement component; and bonding the first layer to the second layer. The biodegradable component may comprise a wetting agent, a hydrophilic biodegradable material, or the like.

In an embodiment, a third layer may also be created, the third layer comprising a nonbiodegradable component, where the third layer is also bonded to the first layer.

The scope of protection is not limited by the summary of an exemplary embodiments set out above, but is only limited by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a planar schematic view of a process line for preparation of thermally point-bonded Cotton-Core Non-wovens on spunbond line by laminating cotton and meltblown webs onto the spunbond web; [0010]
FIG. 2 is a planar schematic view of a process line for preparation of thermally point-bonded Cotton-Surfaced Non-wovens on the spunbond line by introducing a carded cotton/polypropylene web on one or both sides of the spunbond web; [0011]
FIG. 3 is a planar schematic illustration of lamination and Infrared bonding of CCN non-wovens consisting of a supporting web of spunbonded web and a core of carded cotton/polypropylene web and a top layer of meltblown polypropylene or meltblown EASTAR BIO non-wovens; [0012]
FIG. 3[0013] a is a planar schematic illustration of ultrasonic bonding of CCN non-wovens consisting of a supporting web of spunbonded web and a core of carded cotton/polypropylene web and a top layer of meltblown polypropylene or meltblown EASTAR BIO non-wovens;
FIG. 4 illustrates the effect of percentage of Cotton in Cotton/polypropylene core content on Tenacity; [0014]
FIG. 5 illustrates the effect of meltblown weight on Tenacity with core of 75% Cotton/25% PP; [0015]
FIG. 6 illustrates the effect of meltblown weight on Tearing Strength with core of 75% Cotton/25% PP; [0016]
FIG. 7 illustrates the effect of Cotton/polypropylene core content and meltblown Weight on Tenacity; [0017]
FIG. 8 illustrates the effect of Cotton/polypropylene core content and meltblown Weight on Tearing Strength; [0018]
FIG. 9 illustrates absorption versus time curves (meltblown side) for laminates containing meltblown EASTAR BIO GP Copolyester webs; [0019]
FIG. 10 illustrates absorption versus time curves (spunbond side) for laminates containing meltblown EASTAR BIO GP copolyester webs; [0020]
FIG. 11 illustrates directional Flow Rate/Orientation of E-29-01-1 spunbond side; [0021]
FIG. 12 illustrates directional Flow Rate/Orientation of E 29-01-1 meltblown side; [0022]
FIG. 13 illustrates directional Flow Rate/Orientation of E-29-01-3A on spunbond side; [0023]
FIG. 14 illustrates directional Flow Rate/Orientation of E-29-01-3 HS On spunbond side; and [0024]
FIG. 15 illustrates directional Flow Rate/Orientation of E-29-01-4A HS on spunbond side.[0025]

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENTS

EASTAR BIO GP COPOLYESTER (“EASTAR BIO”) is marketed by the Eastman Chemical Company of Kingsport, Tenn.. Spunbond/Cotton/meltblown (SCM) Cotton-Core Non-wovens (CCNs) comprising a biodegradable web, such as one comprising a totally biodegradable polymer such as an EASTAR BIO meltblown web instead of meltblown polypropylene webs, were produced and compared to CCNs containing polypropylene in both the meltblown and spunbond components. The absorbent cores had a weight of 1.5 oz/yd[0026] ²(51 g/m²) and consisted of carded 75/25 and 50/50 Cotton/polypropylene staple fiber blends. The laminates were all infrared bonded and evaluated for tearing strength, tenacity, and water absorption rate and maximum absorption. Use of EASTAR BIO meltblown in place of meltblown polypropylene resulted in stronger well-bonded laminates with exceptionally high absorbency on the EASTAR BIO meltblown side as well as in the cotton core.
Cotton-based non-woven materials may include cotton-core non-wovens (CCNs) and/or cotton-surfaced non-wovens (CSNs). CCN laminates are typically a three-layered structure with cotton or cotton/polypropylene webs in the center, or core, layer bonded with spunbond (“SB”) and meltblown (“MB”) webs as top and bottom layers. It has been discovered that a cotton composite with enhanced biodegradable properties occurs when a meltblown polypropylene (“PP”) web is replaced with a totally biodegradable meltblown web, such as one made using EASTAR BIO. [0027]
Although meltblown and spunbond webs have been produced with 100% EASTAR BIO, and may be laminated on both sides of a cotton-core web, to produce a totally biodegradable SCM CCN laminate, it has been discovered that better thermal bonding of cotton core fibers to each other and to the outer spunbond or meltblown fabrics may be achieved by blending thermoplastic staple fibers with the cotton fibers. However, the staple fibers should be essentially biodegradable in order for the entire CCN to be biodegradable. This may be achieved by producing a bicomponent staple fiber with a core of biodegradable poly(lactide) (PLA), e.g. to achieve the desired mechanical strength and moderate to low elasticity for carding, and a sheath of a biodegradable material such as EASTAR BIO for the desired ease of thermal bonding, good adhesion, and good wetability. Although the core/sheath bicomponent fiber geometry may be a preferred geometry, numerous other bicomponent fiber geometries may also be suitable such as side-by-side, segmented, and islands-in-the-sea. The types of degradable CCNs that may be produced comprise: [0028]
1. 100% meltblown EASTAR BIO outer layer/100% Cotton Core/100% meltblown EASTAR BIO outer layer [0029]
2. 100% spunbond EASTAR BIO outer layer/100% Cotton Core/100% spunbond EASTAR BIO outer layer [0030]
3. 100% spunbond EASTAR BIO outer layer/100% Cotton Core/100% meltblown EASTAR BIO outer layer [0031]
4. 1, 2 and 3 above except the core cotton-based web has a blend of cotton (or any cellulose fiber) with EASTAR BIO staple fibers for improved thermal bonding [0032]
5. 1, 2, 3 and 4 in which the EASTAR BIO webs may be replaced with poly(lactide) webs on one or both sides of the cotton-based core web. [0033]
6. MELTBLOWN or spunbond bicomponent fiber webs, preferably with a core of poly(lactide) and a sheath of EASTAR BIO, but with any of the possible bicomponent fiber geometries, may replace any of the meltblown or spunbond outer webs in the above constructions. [0034]
Since the meltblown polypropylene in the above CCNs was successfully replaced with a totally biodegradable polymer, numerous other biodegradable polymers such as poly(lactide) may also be candidates for replacing the meltblown polypropylene or EASTAR BIO. Further, the polypropylene in the spunbond web of the CCNs may be replaced with biodegradable polymers such as EASTAR BIO, poly(lactide), polyvinyl alcohol, and copolymers of polyhydroxybutyrate (PHB)-polyhydroxyvalerate (PHV). Furthermore, the thermoplastic staple fibers such as polypropylene, which may be blended with the cotton fibers in the center “core” layer to improve the thermal bonding of the CCN laminate, may be replaced with biodegradable fibers such as those noted above, as well as others. [0035]
Additionally, biodegradable Cotton-Surfaced Non-wovens (CSNs) may be produced. Among the possible embodiments for producing biodegradable CSNs are the following constructions: [0036]
a. Base supporting web of spunbond poly(lactide) and top web of cotton (or any cellulose fiber) blended with staple poly(lactide) fibers with is subsequently thermally calendered, or bonded by hot through-air, ultrasonic or infrared thermal bonding methods. [0037]
b. Structure “a” above in which cotton fibers are blended with bicomponent core/sheath (or any possible bicomponent fiber geometry) with a core of poly(lactide) and a sheath of EASTAR BIO. [0038]
Structures “a” and “b” above in which cotton webs blended with poly(lactide) or with bicomponent fiber (preferably a core of poly(lactide) and a sheath of EASTAR BIO. [0039]
Furthermore, the CSN constructions above may be heat-stretched in one direction to produce elasticity in the CSN in the direction perpendicular to the direction of stretch (or biased to the direction of stretch) and to induce wetting and wicking in the direction of stretch. [0040]
Referring now to FIG. 1, a non-woven composite may comprise a plurality of layers. In a first exemplary embodiment, a first layer, further comprising a biodegradable component is bonded to a second layer, further comprising a biodegradation enhancement component. The first layer may further comprise a thermoplastic biodegradable fiber where the thermoplastic biodegradable fiber may further comprise at least one of EASTAR BIO, poly(lactide), polyvinyl alcohol, other biodegradable fibers, or bicomponent fibers with biodegradable components, or the like, or a combination thereof. The second layer may comprise a spunbond non-woven material, a meltblown non-woven material, or the like. [0041]
In a further exemplary embodiment, the non-woven composite may further comprise additional layers. For example, the non-woven composite may comprise a third layer. In such an embodiment, the second layer may comprise a meltblown layer bonded on a first outer surface of the first layer and the third layer may comprise a spunbond layer bonded to a second outer surface of the first layer disposed opposite the first outer surface. [0042]
The first layer may further comprise a cellulosic fiber blended with a thermoplastic fiber, the thermoplastic fiber further comprising polyethylene, polypropylene, polyester, nylon, a low melting point fiber, a bicomponent fiber, or the like, or a combination thereof. At least one of the outer spunbond or meltblown layers may comprise a biodegradable polymer, the biodegradable polymer further comprising poly(lactide), EASTAR BIO, polyvinyl alcohol, other biodegradable polymers, or the like, or a combination thereof. [0043]
Bonding may be accomplished by calender patterned bonding, ultrasonic patterned bonding, infrared bonding, hot air bonding, or the like, or a combination thereof. [0044]
The biodegradation enhancement component may be a wetting agent or a hydrophilic biodegradable material or the like, or a combination thereof. The wetting agent makes the non-woven composite more wettable. [0045]
Referring still to FIG. 1, CCNs may be produced by sandwiching a cotton web between outer layers of a meltblown and/or a spunbond web such as by using a thermal calendaring process. In an exemplary embodiment, a bleached cotton web is introduced into a production line after extrusion and laying of spunbond polypropylene, and a meltblown polypropylene web may be introduced into a production zone after the cotton web so as to develop a three layered structure in which one or more cotton webs is bonded in between a spunbond layer and a meltblown layer. A spunbond polypropylene web and a meltblown polypropylene web may act as binder fibers in the thermal bonding and may be engineered to transport liquid into a highly absorbent cotton core from its dry surfaces. The absorbent core and the dry surfaces make CCNs highly suitable for diaper components, feminine hygiene products, baby wipes, sponges, bandages, surgical gowns and other industrial and consumer applications. [0046]
Heat-stretching the CCNs may impart instantaneous elastic recoveries of up to 70%-80% from an extension of 50%. Heat-stretching in one direction imparts elasticity to the laminate in the other direction. For example, if a non-woven composite laminate is heat-stretched in the machine direction, as that term is understood by those of ordinary skill in the art, then it will be elastic in the cross-machine direction, as that term is understood by those of ordinary skill in the art. Elastic non-wovens such as a laminate possess excellent comfort and fit properties useful in applications such as inexpensive elastic leg cuffs and waist bands for disposable diapers. Elastic CCNs have improved wicking properties, in addition to stretchability, due to the greater orientation of cotton and polypropylene fibers in the machine direction which makes them ideal for protective apparel, face masks, bandages, wound dressings, feminine hygiene products and diapers. [0047]
Referring now to FIG. 2, Cotton-Surfaced Non-wovens (CSNs) have been developed with cotton on one or both sides of a base structure, generally a spunbonded polypropylene web, in which the cotton content varies from 20-70% of the fabric weight. As shown in FIG. 2, CSNs may be made by placing a carded cotton/polypropylene web on one or both sides of spunbond polypropylene filament webs prior to calendaring rollers. The thermally bonded two or three layered laminates are soft but strong and have excellent wetting, wicking, water absorption, and water retention properties. They are ideally suited as cotton-surfaced outer fabrics for diapers, acquisition layers in diapers and feminine hygiene products, disposable bed linens and textile interfacings. A post-treatment process enhances the extensibility of the fabrics produced with instantaneous elastic recoveries of 83%-93% from an extension of 50%. [0048]
These elastic fabrics also exhibit minimal Tinting characteristics and would be suitable as isolation gowns, or drapes and gowns (if fluorochemical finished), physical therapy pants, head covers and shoe covers, bed sheets, pillow cases and for consumer applications such as disposable underwear, towels, wipers and personal hygiene products. [0049]
A cotton web may comprise a bleached cotton staple used for the initial stage of fabric development such as a premium medical grade with excellent absorbency, entanglement potential and comfort characteristics. Additionally, additional grades of cotton may be incorporated into CSN and CCN composites with similar results as well. [0050]
Referring now to FIGS. 3 and 3[0051] a, CCNs may be bonded using infrared bonding, ultrasonic bonding, or the like.
In the operation of an exemplary embodiment, a non-woven composite may be produced by creating a first layer which comprises a first biodegradable component, e.g. cotton or another cellulosic fiber. A second layer may be created, the second layer comprising a biodegradation enhancement component such as a wetting agent or a hydrophilic biodegradable material. In a preferred embodiment, a wetting agent may be added topically to a layer comprising spunbond material. [0052]
The first layer may then be bonded to the second layer. The second layer may further comprise a spunbond material, a meltblown material, or the like, or a combination thereof. [0053]
A non-elastic thermoplastic component may be added to the biodegradable component in the first layer. Further, the non-elastic thermoplastic component and the biodegradable component may be heat-stretched in either the machine or cross-machine direction. [0054]
Additionally, a laminate having a third layer may be created where the third layer comprises a nonbiodegradable component. The third layer may be bonded to the first layer, e.g. the biodegradable, such that the third layer is on a side of the first layer opposite the second layer. [0055]

In a first exemplary method of preparation, an spunbond polypropylene comprising polypropylene 3155, 35 MFR, marketed by ExxonMobil Chemical Company of Houston, Tex., with basis weights of 11 and 17 g/m ²were first produced on a 1-meter Reicofil 2 spunbond Line. Next, carded webs with a weight of 51 g/m²(1.5 oz/yd²) at a width of 28 inches in compositions of 50% cotton (VERATEC EASY STREET)/50% staple polypropylene (FiberVisions T-156, 2.2 denier×1.5 in.), and 75% cotton/25% staple polypropylene were deposited from the card onto the 11 and 17 g/m²spunbond polypropylene webs. Rolls of unbonded carded web/SB polypropylene laminates were laminated to meltblown webs as shown in FIG. 3a. Two laminates, Sample 1 (E-29-01-1) and Sample 2 (E-29-01-2), illustrated in Table 1, were produced by adding a 34 g/m²meltblown EASTAR BIO web instead of meltblown polypropylene with two-ply combinations of 11 g/m²spunbond polypropylene and carded cotton/polypropylene webs consisting of 75% cotton/25% polypropylene and 50% cotton/50% polypropylene. The remaining samples illustrated in Table 1 were prepared by laminating the carded cotton/polypropylene and spunbond polypropylene combinations with 30-inch meltblown polypropylene webs with basis weights of 12 and 16 g/m².

TABLE 1


Description of Biodegradable Cotton-Core Non-wovens (CCN's)

			Web Wt.
Sample		Core Content*	(G/m²)	IR Bonded

#/Descr.	Laminate	C/polypropylene	SB	MB	T/FPM

1	E-29-01-1	75/25	11	34**	164F/34
2	E-29-01-2	50/50	11	34**	164F/34
3	E-29-01-3A	75/25	11	12	200F/38
4	E-29-01-4	50/50	11	16	200F/38
5	E-29-01-5	50/50	11	12	200F/38
6	E-29-01-6A	75/25	11	12	200F/38
7	E-29-01-7A	75/25	11	16	200F/38
8	E-29-01-3 HS***	75/25	11	12	200F/38
9	E-29-01-4A HS***	75/25	11	—	200F/38
10	E-29-01-5A HS***	50/50	11	16	200F/38

The 34 g/m[0057] ²meltblown EASTAR BIO was produced on a 20-inch ACCURATE PRODUCTS meltblown line. The web was collected on release paper. Alternatively, water spray quench may be utilized between the die and collector in order to avoid the use of release paper to prevent the web from sticking to the collector. Although thermal calendaring may be used to bond the webs as depicted in the preparation of CCNs in FIG. 1, CCN laminates may also be bonded utilizing infrared (IR) bonding.
Laminates 1 and 2 were bonded by placing the spunbond polypropylene side on top for impingement of the infrared radiation with the [0058] infrared heater 8 inches above the spunbond polypropylene. The line speed was 34 feet/min and a nip roller after the IR heater was heated to 164° F. with a nip pressure of 80 psi. These conditions were sufficient to bond the spunbond polypropylene to the cotton/polypropylene webs and also resulted in excellent bonding of the EASTAR BIO and spunbond polypropylene to the carded cotton/polypropylene center webs. Laminates 3 through 7 illustrated in Table 1 were first bonded using infrared bonding under the same conditions as samples 1 and 2, except meltblown polypropylene webs were placed on the bottom and the line was increased to 45 feet/min. It was later found that the meltblown polypropylene webs were not well-bonded and Samples 3-7 were bonded using infrared bonding a second time with the meltblown polypropylene webs on top and exposed to the infrared bonding unit and the height of the infrared bonding unit was reduced to 7 inches. Also, the nip roller was heated to 200° F. with a nip pressure of 80 psi and the line speed was 38 feet/minute.
Also as noted in Table 1, approximately 20-meter lengths of [0059] laminates 3, 4 and 5 were heat-stretched ( laminates 8, 9 and 10 respectively) through a 6-ft forced hot air oven at a temperature of 300° F. The first pair of nip rolls had a surface speed of 3.8 m/min and the second pair of nip rolls had a speed of 7.2 m/min, resulting in a draw ratio of 1.9.
In a second exemplary embodiment, ultrasonic bonding (UB), like infrared bonding described in the previous section a bonding technique which does not compress a laminate as much as thermal point-bonding in a calendar, was utilized. [0060]
Thermoplastic polyurethanes have been developed in recent years, which have the elasticity of thermoset cross-linked rubber or SPANDEX, but do not have to be solvent spun like SPANDEX, for example. The thermoplastic polyurethanes can be spun into fibers by more environmentally friendly melt spinning process and the addition of cotton to the surface of meltblown thermoplastic polyurethanes and spunbond thermoplastic polyurethane fabrics will made them even more suitable with the comfort and biodegradability afforded by the cotton component. Furthermore, thermoplastic polyurethanes can possess hydrophilic backbone chemistry and be breathable. During preliminary meltblown trials it was observed that the thermoplastic polyurethane filaments were often traveling horizontally from meltblown die only a few inches or more, depending on air flow rates, before dropping vertically towards the floor. This observation coupled with the fact that relatively large diameter meltblown fibers were being produced led the inventor to believe that efforts had been going in the wrong direction with respect to spinneret hole diameter and air knife gap. With many high melt viscosity polymers such as polyesters and nylons, a large hole die (0.018 inch hole diameter compared to the standard hole diameter of 0.0145 in.) and larger air knife gap of 0.090 inches actually results in finer fibers and softer webs. However, based on observations described above, the standard die tip with 0.0145 in. diameter holes and with an LID of 8.5/1 and a hole density of 25 holes/inch was used. Also, the air knife gap on both sides of the nose tip was reduced to 0.030 in. and the die tip setback to 0.030 in. These innovations enabled us to produce uniform meltblown thermoplastic polyurethane webs with fiber diameters of 5 micrometers, well in the microfiber range (data not shown). [0061]
In an effort to successfully produce spunbond thermoplastic polyurethane, which would enable the production of cotton-surfaced spunbond thermoplastic polyurethane, Two resins, 58283-045 and X-4981-045, were obtained from Noveon, Inc. of Cleveland, Ohio. These resins were re-extruded to lower molecular weight and a filler was added to both resins to minimize sticking of the extruded filaments before quenching. [0062]
In a third exemplary embodiment, additional carded webs of Barnhardt bleached raw cotton were prepared at a basis weights of 13 grams/square-meter (“gsm”) for the preparation of CSNs and at weights of 40-51 gsm for the preparation of CCNs. Also, since the bicomponent core/sheath (c/s) staple fibers with a core of poly(lactide) (for strength and low elongation for good carding) and a sheath of EASTAR BIO (for good thermal bonding and biodegradability) were not be available, a bicomponent C/S polypropylene/EASTAR BIO staple fiber was selected for blending with cotton fiber to form carded webs for the preparation of CCNs and CSNs. Replacement of the polypropylene with poly(lactide) in the bicomponent binder core/sheath fiber will make the bicomponent fiber completely biodegradable. [0063]
Wicking and absorption properties (to distilled water) of all the samples were evaluated using an ATS-600 Absorbency Testing System which is a table top instrument that measures the absorption and desorption rate and total capacity of absorbent materials. The desorption of these samples was not determined. All samples were cut from the sheets into 2-inch squares and placed on the table oriented in the same direction. Results were corrected for sample weight and appear in grams/gram. The Cotton-Core samples were tested on the spunbond (SB) side, except the laminates with meltblown EASTAR BIO were also tested on the meltblown side. Tests were run for a period of time, usually 100-300 seconds, to ensure that absorption had tapered off, and the differential fluid head was set approximately at zero. [0064]
FIG. 4 illustrates the effect of the percentage of cotton in a cotton/polypropylene core on tenacity. [0065]
FIGS. 5 and 6 illustrate that an increase in the basis weight of meltblown web in the CCN laminate also had minimal effect on the tenacity and tearing strength. [0066]
FIG. 7 illustrates that the machine direction tenacity values of the heat-stretched laminates are greater than that of As-Bonded laminates. Heat-stretching increased the fabric orientation and compactness of the fabric, which helped in increasing the strength of the fabric and tenacity of the fabric. The machine-direction/cross-machine-direction ratio of tenacity values for all the laminates is >2.5. [0067]
Referring now to FIG. 8, there are no clear trends in tearing strength in the heat-stretched samples in either machine or cross-machine directions when compared to the As-Bonded laminates. [0068]
Referring now to FIG. 9, a graph of absorption versus time curves on a meltblown side for laminates containing a meltblown EASTER BIO web, the sample with 50% cotton in the core, E 29-1-2, had slightly lower absorption than the sample containing 75% cotton in the core, E 29-1-1. [0069]
Referring now to FIG. 10, in which the above samples E 29-1-1 and E-29-1-2 were wetted from the spunbond polypropylene side instead of the meltblown side, as above, both laminates absorbed nearly as much water with time from the spunbond polypropylene side as from the meltblown EASTAR BIO side as illustrated in FIG. 9. [0070]
The maximum absorption values are expectedly slightly lower when tested from the spunbond side at 6.4 grams/gram and 6.1 grams/gram respectively for the CCNs containing 75 and 50% cotton in the cotton/polypropylene cores. [0071]
In a further embodiment, a laminate, E 29-1-3 HS, containing higher cotton content (75%) had a greater absorption amount and a second laminate, E 29-1-5A, containing 50% cotton, had the second highest absorption amount. The maximum absorption values for three laminates E 29-1-3, E 29-1-5A HS, and E 29-1-4A, were 9.6 grams/gram, 9.4 grams/gram, and 8.0 grams/gram respectively. Comparing the maximum absorption amount values of the Heat-Stretched laminates with the As-Bonded laminates, for the laminates containing higher cotton content, Heat-Stretching produced minimal changes in the absorption properties. After the Heat-Stretching the laminates were oriented in the machine direction and their directional absorption properties were prominent in the machine direction. Directional flow rates of As-Bonded samples containing 75% Cotton/polypropylene and 50% Cotton/polypropylene in the cotton based cores and the corresponding Heat-Stretched CCNs are illustrated in FIGS. [0072] 12-15. As is illustrated in FIGS. 12-15, the As-Bonded CCNs have a more circular wetting pattern and the CCN webs with 50% cotton/polypropylene in the core had a smaller wetting area and a slower wicking rate. The Heat-Stretched samples exhibited greater directional flow in that the machine direction/CD rates were greater.
In a further embodiment, in order to improved the wettability of CSNs and CCNs for hygienic products and for other products such as wound dressings and absorbents in the packaging of meats, as well as to improve water absorption to better facilitate the biodegradation processes of the degradable components of CCNs and CSNs, a study was made to determine the best method of adding wetting agents to spunbond polypropylene. [0073]
Additional follow-up in determining the most cost-effective method for producing acceptable wettability and rewettability in spunbond polypropylene led to the evaluation of two new fluorosurfactant (FS) type wettable concentrates, S-1242, a monomer-based fluorosurfactant, and S-1243, a polymer-based fluorosurfactant, both available from Polyvel Inc. of Hammonton, N.J. It was found that both fluorosurfactant concentrates improved the wetting performance of cotton composites containing spunbond polypropylene. It was further found that of the two, the polymer-based fluorosurfactant gave better wetting properties than the monomer-based fluorosurfactant. [0074]
In a further embodiment, in an effort to determine if lower grades of less expensive cotton other than bleached first quality cotton could be used to produce CCNs and CSNs, three 75-lb bags, each of two grades of greige re-ginned cotton motes (Grade 1H50 and [0075] Grade 1, with a slightly lower quality having more trash content) were obtained from T. J. Beall Company, West Point, Ga. for the preparation of two weights of carded webs in a 50/50 blend with FiberVisions Type 196 polypropylene staple fiber with a hydrophilic spin finish. Both the 13 g/m2 (gsm) and the 36-40 gsm carded webs described above were rolled up with tissue paper during the carding work for the preparation of CCNs and CSNs.
In yet a further embodiment, for preliminary work in the preparation of CSNs with wettable spunbond polypropylene on an [0076] spunbond line 100 pounds of wettable concentrate, S-1180, a concentrate with 7% silica, 15% surfactant, and 78% polypropylene, were obtained from Polymer Applications Inc., Lawrenceville, N.J. The wettable concentrate was mixed at 4% and 6% (weight %) levels with 35 MFR polypropylene before spunbond extrusion. For a comparison of the wettability of the base spunbond polypropylene webs, 200-meter rolls of 12 g/m2 (gsm) spunbond polypropylene with no wetting agent and rolls with 4% and 6% wettable concentrate were produced. Three 200-meter rolls of 17 gsm spunbond polypropylene with 6% wettable concentrate were also prepared for the preparation of CCNs.
In yet a further embodiment, EASTAR BIO was meltblown to produce meltblown EASTAR BIO web with a weight of 27 gsm for the subsequent preparation of mostly biodegradable CCNs. [0077]
Also, 50 lbs of bicomponent core/sheath (c/s) staple fiber with a core of polypropylene and a sheath of EASTAR BIO were obtained with the following specifications: 50% polypropylene core/50% EASTAR BIO; 4 denier/filament; 1.4 inch staple length; and 9.4 crimps/inch. This bicomponent fiber was then mixed and carded in blends of 60% bleached cotton/40% bicomponent and 70% bleached cotton/30% bicomponent to produce carded webs with weights of 11 gsm, 22 gsm, 25 gsm and 36-40 gsm and rolled with tissue paper for subsequent unwinding to laminate for other webs to produce SCNs and CCNs as specified in this document. [0078]
In addition, 30 yards of 20 gsm spunbond poly(lactide) at a width of 15 inches was also obtained from Cargill Dow for preparation of CSNs and CCNs. [0079]
CSNs were prepared on a 1.0 [0080] meter Reicofil 2 spunbond line in which 13 gsm carded bleached cotton/polypropylene staple fiber webs (50/50 cotton/polypropylene and 60/40 cotton/polypropylene) were thermally bonded to 12 gsm spunbond polypropylene webs with 4% and 6% wettable concentrate. Bonding of the CSNs produced with the wettable concentrate appeared to be much better than had here-to-fore been produced with spunbond polypropylene not containing wetting agent. CSNs were also prepared with spunbond base webs containing 6% wettable concentrate in which carded webs of greige reginned cotton motes formed the surface layer.
CSNs were prepared with spunbond base webs containing 6% wettable concentrate in which carded webs of greige Cotton Gin Motes formed the surface layer. Carded 10 gsm re-ginned cotton motes consisting of 50% [0081] Gray Beall Grade 1/50% polypropylene staple and 50% Greige Bealls Grade lH50/50% staple polypropylene were unrolled onto the 12 gsm spunbond polypropylene (6% wettable concentrate). Also, a 36 gsm carded web of 50% Greige Bealls 1H50 and staple polypropylene was laid onto the wettable 12 gsm spunbond polypropylene web and thermally point bonded on the spunbond line. It was anticipated that the natural waxy coating on the greige cotton fiber would adversely affect bonding to the spunbond polypropylene. Nevertheless, excellent bonding of the greige re-ginned cotton mote/staple polypropylene blend was obtained to the wettable spunbond polypropylene, as was obtained with the CSNs containing bleached cotton blend surface webs. The spunbond run conditions for the preparation of the above samples on the 1.0 m spunbond line were as follows and it should be noted that in the preparation of all CSNs on the spunbond line in this study, the top heated calender roller had a raised diamond pattern with a bonding area of 14.7% and the bottom heated calender roller was smooth steel:
A. Preparation of 12 gsm spunbond polypropylene controls with no S-1180 and with 4 and 6% S-1180: [0082]
1) Die Zones 4.1 and 4.7: 445 F. (229° C.) [0083]
2) Melt temp: Die 1-384 F.(195.6° F.); Die 2: 422° F. (216.7° C.) [0084]
3) Thru-put of 0.15 gram/spinneret hole/min (g/h/m) [0085]
4) Quench Air Temp of 64° F.; Cooling Air Fan at 1586 RPM [0086]
5) Suction Fan at 1469 RPM [0087]
6) Belt Speed of 59.4 m/min [0088]
7) Calender Speed of 62 meter/min (m/m) [0089]
8) Winder Speed of 64 m/m [0090]
9) Calendering Conditions: 265° F. Top/261° F. (Bottom); 141 PLI (lbs/linear inch) Nip Pressure. [0091]
B. Preparation of CSNs with 4 and 6% S-1180: [0092]
1) Increase Calender Temps to 290° F. Top/285° F. Bottom [0093]
2) Increase PLI to 618 PLI [0094]
3) Unwind unbonded carded cotton-blend webs (while removing the tissue paper used to roll up the carded webs) onto unbonded spunbond filament web prior to the thermal calender section [0095]
4) Other line conditions same as “A” above without cotton lamination [0096]
Similar CSNs were then also made onto 12 gsm containing 5% S-1242 fluorosurfactant and 5% S-1243 fluorosurfactant. The run conditions for the 12 gsm spunbond polypropylene without and with 5% S-1242 and 5% S-1243 are as follows: [0097]
A. Preparation of 12 gsm spunbond polypropylene with no wetting agent and with 5% S-1242 and 5% S-1243: [0098]
1) Die Zones 4.1 and 4.7: 445° F. (229° C.) [0099]
2) Melt temp: Die 1-379 F. (192.8° C.); Die 2-421° F. (216° C.) [0100]
3) Thru-put of 0.15 g/h/m [0101]
4) Quench Air Temp of 64° F.; Cooling Air Blower at 1586 RPM [0102]
5) Suction Fan at 1469 RPM [0103]
6) Belt Speed of 59 m/min (mpm) [0104]
7) Calender Speed of 61 mpm [0105]
8) Winder Speed of 64 mpm [0106]
9) Calendering Conditions: 265° F. Top/262° F. (Bottom); 200 PLI Nip Pressure [0107]
B. Preparation of CSNs with 5% S-1242 and with 5% S-1243: [0108]
1) Increase Calender Temps to 290° F. Top/286° F. Bottom [0109]
2) Increase PLI to 618 [0110]
3) Unwind unbonded carded cotton-blend webs onto unbonded spunbond filament web prior to calender [0111]
4) Other conditions same as “A” above with run of no cotton with S-1242 and S-1243 in spunbond polypropylene. [0112]
In all of the above runs, the belt speed, calender speed and winder speeds were simply reduced to produce 17 gsm spunbond polypropylene with and without 4% and 6% S-1180 and 5% S-1242 and S-1243 for subsequent preparation of CCNs and SCNs for thermal bonding and ultrasonic bonding. [0113]
The spunbond EASTAR BIO was produced on a 1.0 [0114] m Reicofil 2 spunbond line. First, two 200-meter rolls comprising 25 and 48 gsm spunbond EASTAR BIO were produced without the application of cotton-blended surface webs. Then, carded 11 and 25 gsm webs of 70% bleached cotton/30% bicomponent staple consisting of a core of polypropylene and a sheath of EASTAR BIO were unwound onto a 48 gsm and 25 gsm EASTAR BIO spunbond web just before the calendaring component of the spunbond line. Excellent bonding of the cotton blended webs to the spunbond EASTAR BIO webs has been achieved and these essentially biodegradable CSNs are highly absorbent and are elastic in all directions with good strength and dimensional stability. If complete biodegradability is desired, the polypropylene in the bicomponent fiber may be replaced with an inelastic biodegradable fiber such as poly(lactide). The spunbond conditions on the 1.0 m spunbond line for the preparation of 25 gsm spunbond EASTAR BIO were as follows:
A. Preparation of 25 gsm spunbond EASTAR BIO without cotton web addition: [0115]
1) Extruder: Zone 1.1-332° F. (166.7° C.); Zone 1.4-378° F. (192° C.) [0116]
2) Die Zones: Die 4.1-405° F. (207° C.); Die 4.4-384° F. (195.6° C.); Die 4.7-404° F. [0117]
3) Melt temp: Die 1-365° F. (185° C.); Die 2-389° F. (198° C.) [0118]
4) Thru-put of 0.15 g/h/m [0119]
5) Quench Air Temp of 46° F.; Cooling Air Blower at 1859 RPM [0120]
6) Suction Fan at 1652 RPM [0121]
7) Belt Speed of 41 meters/min. (mpm) [0122]
8) Calender speed of 53 mpm [0123]
9) Winder Speed of 55 mpm [0124]
10) Calendering Conditions: Top Roll-171° F.; Bottom Roll-167° F.; 53 PLI Nip [0125]
B. Preparation of CSNs on 25 gsm spunbond EASTAR BIO: [0126]
1) Increase calender nip to 544 PLI and leave all of the above “A” conditions the same [0127]
2) Unwind the carded cotton-blend webs onto the unbonded 25 gsm EASTAR BIO filament web prior to the thermal calender. [0128]
The spunbond runs conditions for the 48 gsm EASTAR BIO were as follows: [0129]
A. Preparation of 48 gsm spunbond EASTAR BIO without cotton web addition: [0130]
1) Extruder: Zone 1.1-330° F. (165.6° C.); Zone 1.4-377° F. (191.7° C.) [0131]
2) Die Zones: Die 4.1-405° F. (207 C.); Die 4.4-377° F. (191.7° C.); Die 4.7-405° F. [0132]
3) Melt temp: Die 1-365° F. (185° C.); Die 2-389° F. (198° C.) [0133]
4) Thru-put of 0.15 g/h/m [0134]
5) Quench Air Temp of 40° F.; Cooling Air Blower at 1865 RPM [0135]
6) Suction Fan at 1652 RPM [0136]
7) Belt Speed of 41 meters/min. (mpm) [0137]
8) Calender speed of 26 mpm [0138]
9) Winder Speed of 28 mpm [0139]
10) Calendering Conditions: Top Roll-171° F.; Bottom Roll-167° F.; 52 PLI Nip [0140]
B. Preparation of CSNs on 48 gsm spunbond EASTAR BIO: [0141]
1) Increase calender nip to 544 PLI and leave all of the above “A” conditions the same [0142]
2) Unwind the carded cotton-blend webs onto the unbonded 48 gsm EASTAR BIO spunbond filament web prior to the thermal calender [0143]
In a further embodiment, thermally-point bonded CCNs may be thermally-point bonded using the same calendering conditions as described herein above. CCNs to be thermally-point bonded may be prepared by depositing a carded cotton blend web of the appropriate weight, composition, and width onto a predetermined spunbond polypropylene, e.g. 17 gsm, with the specified wetting agent. Then a meltblown polypropylene web, e.g. 12 gsm, may be laid onto the laminate on the side opposite from the spunbond web. Un-bonded CCN may then be unrolled such as onto a 1.0 [0144] m Reicofil 2 spunbond line, e.g. without the spunbond extrusion die in operation, and run through a thermal calender with the meltblown side positioned against a patterning device, e.g. a heated raised diamond patterned (14.7% bonding area) steel roller, and the spunbond polypropylene web positioned against a second device, e.g. a heated bottom smooth steel roller. In an embodiment, the patterned roller temperature was 266° F., the bottom smooth roller was 261° F., the nip pressure was 500 PLI, and the calender surface speed was 20 meters/min.
In a further embodiment, CCN and CSN laminates may be ultrasonically bonded, such as using a [0145] Branson 184V 20 kHz laboratory unit. In an embodiment, one of two 10-inch wide ultrasonic horns was engaged on the laboratory unit. The setting on the laboratory unit was 60 with a 20 load factor and the gap was 15 mils. The fabric speed through the unit was 2 meters/min.
When CCN or SCN were ultrasonically bonded, the highly elastic meltblown or spunbond EASTAR BIO webs could not be on the side next to the ultrasonic horn, but had to be placed on the side against the patterned roller since the vibrating horn would otherwise pinch up under the elastic web causing it to tear. [0146]
In certain embodiments, in order to improve the biodegradability of cotton-based non-wovens, different types of wetting agents were added to the non-biodegradable spunbond polypropylene layer of CSNs and CCNs to better enable water to better penetrate into the structures and enhance the biodegradation process of cotton and other naturally degradable components. Wetting agents were also added to improve the absorption and wicking performance of CSNs and CCNs for personal hygiene applications such as baby diapers, sanitary napkins, panty liners and pre-wetted wipes, as well as for wound dressings and absorbent pads in meat packaging. [0147]

As shown in Table 2, CSN “o” consists of a 2-layer thermally point bonded laminate with a carded 13 g/m2 (gsm) web of 50% bleached (Ed Hall) cotton/50% staple polypropylene (FiberVisions T-196) with a hydrophilic finish on top of a 12 gsm spunbond polypropylene substrate containing 6% Polyvel S-1180 wettable concentrate, as mixed in pellet with Exxon 35 MFR polypropylene 3155 pellets prior to the spunbond process. The concentration of silicone-based wetting agent in the S-1100 was 15%, resulting in a net active add-on of wetting agent of 0.9%. CSN “s” only differed from “o” in that the top 13 gsm carded web consisted of a blend of 60% bleached cotton and 40% staple polypropylene T-196. The target weight of both of these samples was 25 gsm and as can be seen in Table 2, the actual weights of “o” and “s” were very close at 24.1 and 25.9 gsm, respectively, and the thickness measurements were 0.31 and 0.31 mm. Both samples also have excellent air permeability, an important attribute for thermal comfort for items worn on or near the body. However, Sample “o”, which had the lower cotton content of 50% exhibited very poor wettability, in that no uptake of water resulted during testing with the ATS-600 unit when the spunbond polypropylene side with 6% S-1100 was subjected to the initial pulse of water to start the test cycle. When the cotton/polypropylene blend side was turned down and subjected the wetting challenge, a small maximum absorption of 2.9 grams of water per gram of sample resulted. Sample “s”, which had 60% cotton allowed some wetting to occur on the spunbond polypropylene side (3.4 g/g) and had a slightly higher absorption of 4.4 g/g from the cotton side. The apparently improved wettability of the spunbond polypropylene side with the higher cotton content on the opposite side may be explained by the fact that these are comparatively thin samples with the cotton and spunbond polypropylene fibers being intermingled at the interface and a greater number of cotton fibers would be in a position to wick water through the sample to the cotton-based side.

TABLE 2


Weight, Thickness, Air Permeability and Maximum Amount of Water
Absorbed and Absorption Rate of Thermally Bonded (TB) CSNs Containing 12 gsm
spunbond polypropylene Substrate with Silicone-based Wettable Concentrate

					Maximum
				Air	Absorption	Absorption
				Permeability	(g/g) & Sec	Rate-1^st60
Sample		Weight	Thickness	(cm³/	in Test	sec (g/g/s)
No.	Description	(gsm)	(mm)	cm²/s)	C-up/C-dn	C-up/C-dn

“o”	13 gsm 50/50	24.1	0.31	222.8	nw	2.9	nw	0.04
	C/polypropylene					(64)
	12 gsm spunbond
	polypropylene/6%
	S-1180 (Silicone)
“s”	13 gsm 60/40	25.9	0.32	277.9	3.4	4.4	0.05	0.07
	C/polypropylene				(180)	(58)
	12 gsm spunbond
	polypropylene/6%
	S-1180 (Silicone)

Given the less than anticipated wetting performance with the S-1180 silicone-based wetting concentrate in the spunbond polypropylene, two fluorosurfactant based wetting agents were obtained from Polyvel, Inc. of Hammonton, N.J. The fluorosurfactant wetting agents are comparatively more expensive than silicone-based compounds, but may be more effective in enhancing polypropylene wetting performance. The two fluorosurfactant concentrates evaluated were S-1242, a monomer-based fluorosurfactant, and S-1243, a polymer-based fluorosurfactant. Both concentrates were mixed with Exxon polypropylene 3155 pellets at a level of 5%, resulting in a calculated add-on of 0.5% of the fluorosurfactant wetting agent on the spunbond fabric. As shown in Table 3, the first two identical samples in Table 3, D3PP1 and D3PP2, which had a 5% addition of S-1242, the monomer-based fluorosurfactant, to the spunbond polypropylene did not take up any water from either the 50/50 cotton/staple polypropylene side or the spunbond polypropylene side during testing on the ATS-600 unit. However, as with the 6% addition of S-1180 to the spunbond polypropylene, the CSNs with 5% S-1242 in spunbond polypropylene and with a top web of 60% cotton/40% staple polypropylene (D4aPP and D4bPP) exhibited some uptake of water. On the other hand, CSNs with 5% addition of the polymer-based fluorosurfactant, S-1243, with both the 50/50 cotton/polypropylene and 60/40 cotton/polypropylene, top webs generally exhibited notably high maximum absorption values and absorption rates. It is believed that the polymer-based fluorosurfactant (S-1243) is less likely to be volatilized off or decomposed by the heat of the spunbond extrusion process and that the polymer molecules will be slower in migrating from the interior of the spunbond polypropylene filaments to the surface, where the fluorosurfactant can be volatized or can be readily washed off. Nevertheless, the cotton/polypropylene side of these CSNs had appreciably higher maximum absorption and absorption rates than did the very wettable spunbond polypropylene side. Sample H1PP, which had 5% S-1243 in the spunbond polypropylene only absorbed a small amount of water on both sides; however, the gray cotton was not scoured or bleached in the top 36 gsm web of 50 % Bealls Grade 1 reginned cotton motes/50% polypropylene staple, was very non-absorbent since the natural pectins and waxes were still on the fiber.

TABLE 3


Weight, Thickness, Air Permeability and Maximum Amount of Water
Absorbed and Absorption Rate of TB CSNs Containing 12 gsm spunbond
polypropylene Substrate with 5% of Two Fluorosurfactant (FS) Concentrates

D3PP1	13 gsm 50/50	26.0	0.33	334	nw	nw	nw	nw
	C/polypropylene
	12 gsm spunbond
	polypropylene/5%
	S-1242
	fluorosurfactant
D3PP2	Same as D3PP1	27.3	0.26	277.0	nw	nw	nw	nw
D4aPP	13 gsm 60/40	24.7	0.31	328.5	3.3	4.0	0.04	0.07
	C/polypropylene				(180)	(180)
	12 gsm spunbond
	polypropylene/5%
	S-1242
	fluorosurfactant
D4bPP	Same as D4aPP	29.6	0.30	288.7	6.4		0.14
					(200)
G2aPP	13 gsm 50/50	26.6	0.31	170.3
	C/polypropylene
	12 gsm spunbond
	polypropylene/5%
	S-1243
	fluorosurfactant
G2bPP	Same as G2aPP	27.0	0.30	295.2	7.3	15.9	0.05	0.15
					(250)	(298)
G3aPP	13 gsm 60/40	24.8	0.28	311.6	nw	12.2	nw	0.11
	C/polypropylene					(252)
	12 gsm spunbond
	polypropylene/5%
	S-1243
	fluorosurfactant
G3bPP	Same as G3aPP	24.5	0.28	321.2
G3cPP	Same as G3aPP	27.5	0.34	295.8	8.3	13.5	0.20	0.35
					(180)	(100)
H1PP	36 gsm 50/50	64.8	0.66	167.4	0.9	0.4	0.04	0.02
	Bealls Gr 1 Gin				(20)	(20)	(1^st
	Motes/						20
	polypropylene						sec
	12 gsm spunbond						for
	polypropylene/5%						both)
	S-1243
	fluorosurfactant

Table 4 illustrates weight, thickness, air permeability and absorption properties for CSNs with a carded cotton blend web on 25 and 48 gsm spunbond EASTAR BIO. The CSNs in Table 4 have air permeability values comparable to similarly constructed CSNs in Table 1 and 2 even though both EASTAR BIO spunbond fabrics are much heavier than 12 gsm spunbond polypropylene. Samples D1E and D3E have top carded webs with weights of 12.5 and 22.6 gsm consisting of 70% bleached cotton and 30% bicomponent (bico) staple fiber with a core of polypropylene and a sheath of EASTAR BIO, on a 25 gsm spunbond EASTAR BIO. Except for the polypropylene component used in the blend with cotton, these samples are biodegradable. The polypropylene in the bicomponent fiber can be replaced with a biodegradable fiber such as poly(lactide), which also had the high modulus required for carding, and thereby make the CSN completely biodegradable. Samples D1E and D3E have maximum absorption values and absorption rates comparable to the CSNs in Table 2 with 5% of the polymer-based fluorosurfactant (S-1243) in spunbond polypropylene. Sample “ah”, which had a 25 gsm carded 70% cotton/30% bicomponent polypropylene/EASTAR BIO on a 48 gsm spunbond EASTAR BIO, had similar absorbency to Samples D1E and D3E, when tested with the cotton blend side up, but when the cotton side was down and subjected to the wetting charge on the ATS-600 unit, the sample transported the water in a manner that resulted in water being left on the testing table in puddles and possibly contributing to an error in absorbency testing.

TABLE 4


Weight, Thickness, Air Permeability and Maximum Amount of water
Absorbed and Absorption Rate of TB CSNs Containing 25 gsm and 48 gsm
spunbond EASTAR BIO Substrates

D1E	12.5 gsm 70 C/30	42.0	0.37	310.6	11.5	15.6	0.09	0.21
	Bico				(219)	(94)
	polypropylene/
	Eastar
	25 gsm spunbond
	EASTAR BIO
D3E	22.6 gsm 70 C/30	56.8	0.52	184.9	11.3	11.8	0.18	0.19
	Bico				80)	(70)
	polypropylene/
	Eastar
	25 gsm spunbond
	Eastar Bio
E1E	13 gsm 60/40	35.4	0.30	327.2
	C/polypropylene
	25 gsm spunbond
	Eastar Bio
E4E	40 gsm 50 Beals	97.2	1.12	197.1
	Grade 1 Cotton
	Reginned Motes/
	50 polypropylene
	25 gsm spunbond
	Eastar Bio
“ah”	25 gsm 70 C/30	74.7	0.48	115.8	10	pdl	0.163	pdl
	Bico				(86)
	polypropylene/
	Eastar
	48 gsm spunbond
	Eastar Bio

The effects of silicone-based and fluorosurfactant wettable concentrates in the spunbond components of thermally point-bonded CCN samples are shown in Table 5. CCN Sample 9/12D had a 12 gsm meltblown polypropylene on the top against the diamond patterned heated calendar roll during thermal bonding of the laminate, a center core of 40 gsm carded 50 % Bealls Grade 1 unbleached reginned cotton motes/50% staple polypropylene, and a 17 gsm spunbond polypropylene web containing 6% silicone based S-1100 against the bottom heated smooth steel calendar roll The fact that the reginned cotton motes had not been scoured and bleached likely contributed to the lack of absorbency of this sample. However, Sample 9/12C which ad a similar construction, except the 51 gsm core had 60% scoured and bleached cotton and 40% staple polypropylene, had notable absorbency when tested from the wettable spunbond side. The meltblown side of the CCNs would not be expected to readily absorb water since the meltblown webs were not treated with wetting agents (although it is feasible to do so) and since the meltblown webs have very fine microfibers with high cover factor compared to spunbond webs. Nevertheless, CCN Sample 9/12D, which had the same construction as 9/12C, except that 5% S-1243 fluorosurfactant was added to the spunbond side, had some absorbency on the meltblown side.

TABLE 5


Weight, Thickness, Air Permeability and Maximum Amount of Water
Absorbed and Absorption Rate of Thermally Bonded (TB) CCNs Containing 12
gsm spunbond polypropylene with Silicone-based and Fluorosurfactant (FS)
Wettable Concentrates

					Maximum
				Air	Absorption	Absorption
				Permeability	(g/g) & Sec	Rate-1^st60
Sample		Weight	Thickness	(cm³/	in Test	sec (g/g/s)
No.	Description	(gsm)	(mm)	cm²/s)	S-up/S-dn	S-up/S-dn

TB	Top Web-	106.4	0.76	22.1	nw	nw	Nw	nw
CCN
	12 gsm MB
9/12A	polypropylene
	(against
	diamond roll)
	Core - 40 gsm
	50% Bealls Gr
	1/50%
	polypropylene
	Bottom Web-
	17 gsm
	spunbond
	polypropylene
	w 6% S-
	1180(Silicone)
TB	Top Web-	79.2	0.622	20.4	nw	5.6	Nw	0.10
CCN	12 gsm MB					(59.7)
9/12C	polypropylene
	(against
	diamond roll)
	Core - 51 gsm
	60% Cotton/40%
	polypropylene
	Bottom Web-
	17 gsm
	spunbond
	polypropylene
	w 6% S-1180
	(Silicone)
TB	Top Web-	81.23	0.63	19.3	3.5	4.9	0.03	0.09
CCN	12 gsm MB				(169)	(57.8)
9/12D	polypropylene
	(against
	diamond roll)
	Core - 51 gsm
	60% Cotton/40%
	polypropylene
	Bottom Web-
	17 gsm
	spunbond
	polypropylene
	w
5% S-1243
	fluorosurfactant

Furthermore, another highly effective wetting agent, CIBA IRGASURF HL 560, has been reported in the product literature of Ciba Specialty Chemicals of Tarrytown, N.Y. It may be mixed as a concentrate in pellet form with 35 MMR polypropylene pellets before melt extrusion in the spunbond or meltblown processes. [0152]

Ultrasonic bonding, like infrared bonding described in the previous section, is a bonding technique which does not compress a laminate as much as thermal point-bonding in a calendar. Thus ultrasonic bonding was investigated as a technique for thermally point-bonding CCN and CSN laminates for sufficient strength for possible use in hygienic applications, while maintaining high loft (greater bulk) in the structure for absorbing and holding liquid. All of the ultrasonically bonded CCNs in Table 6 have high thickness ranging from 1.0-1.5 mm and high maximum absorption when tested from either the meltblown EASTAR BIO sides or on the spunbond sides. All of these samples had very rapid absorption rates when tested from both sides, especially CCN 9/23A-PLA, which had a spunbond poly(lactide) web on the top side against the ultrasonic horn, a 44 gsm core of 70% bleached cotton and 30% bicomponent polypropylene/EASTAR BIO staple binder fiber and a bottom web of meltblown EASTAR BIO against the patterned roller during ultrasonic bonding. However, EASTAR BIO is very hydrophilic in both staple fiber and meltblown components. No difference in the absorption properties were seen between UB CCN 9/23B, which had a 17 gsm spunbond polypropylene web with 6% silicone based S-1180 on top against the horn, and Sample 9/23C, which had a 17 gsm spunbond polypropylene with 5% polymer-based fluorosurfactant 1243. Both of these samples also had a heavy (51 gsm) core of 60% cotton/40% staple polypropylene and a bottom 27 gsm meltblown EASTAR BIO web against the patterned roller. It was not possible to bond any of the samples in Table 6 when the meltblown EASTAR BIO web was placed on top next to the ultrasonic horn because the vibrating horn would pinch the elastic EASTAR BIO web and after accumulating some material under the horn tore holes in the web. On the other hand, when the inelastic webs such as spunbond polypropylene or spunbond poly(lactide) were placed on top against the ultrasonic horn, the laminates were easily ultrasonically bonded without tearing.

TABLE 6


Weight, Thickness, Air Permeability and Maximum Amount of Water
Absorbed and Absorption Rate of Ultrasonically Bonded (UB) CCNs Containing
Wettable spunbond polypropylene Webs and MB and spunbond Eastar Bio Webs

UB	Top Web-17	92.2	1.0	119.9	9.5	8.8	0.16	0.12
CCN	gsm spunbond				(81.3)	(150)
9/23B	polypropylene w
	6% S-1180
	(Silicone) against
	Horn
	Core - 51 gsm
	60% C/40%
	polypropylene
	Bottom Web-27
	gsm MB Eastar
	Bio
UB	Top Web-17	96.1	1.1	118.9	9.6	8.8	0.16	0.12
CCN	gsm spunbond				(77)	(151.7)
9/23C	polypropylene w
	5% S-1243
	(Fluorosurfactant)
	against Horn
	Core - 51 gsm
	60% C/40%
	polypropylene
	Bottom Web-27
	gsm MB Eastar
	Bio
UB	Top Web-20	124.3	1.5	85.6	10.8	9.82	0.18	0.29
CCN	gsm spunbond				(69.7)	(33.7)		(1^st
9/23A-	poly(lactide)							33.7 s)
PLA	against Horn
	Core - 44 gsm
	70% C/30% Bico
	polypropylene
	Core/Eastar Bio
	Sheath
	Bottom Web-27
	gsm MB Eastar
	Bio

The effects of ultrasonically bonding CSNs are illustrated in Table 7. As with the meltblown EASTAR BIO webs above, it was necessary to place the elastic spunbond EASTAR BIO webs on the bottom against the patterned roller to avoid tearing of the Eastar web. With CSN Samples 9/23E and 9/23F, the 48 gsm carded 60/40 cotton/polypropylene webs were placed on top against the horn and UB proceeded with no problem. CSN Sample 9/23B-PLA also bonded well with the spunbond poly(lactide) web on top. All of these samples had comparatively good bulk and air permeability. Samples 9/23E and 9/23F demonstrated excellent maximum absorbency and absorption rate on the when tested on the spunbond side (cotton side up), but the problem with puddles being observed on the ATS-600 testing table, which could cause errors in absorbency determinations, occurred when all three of the samples in Table 7 were tested on the cotton side. CSN Sample 9/23B-PLA, however, did not appear to wet when tested from the spunbond poly(lactide) side.

TABLE 7


Weight, Thickness, Air Permeability and Maximum Amount of Water
Absorbed and Absorption Rate of Ultrasonically Bonded (UB) CSNs Containing
Wettable spunbond Webs and spunbond Eastar Bio Webs

UB	Top Web - 48	88.7	0.85	138.5	13.1	pdl	0.21	pdl
CSN	gsm 60%				(90.7)
9/23E	C/40%
	polypropylene
	(against Horn)
	Bottom Web-
	25 gsm
	spunbond
	Eastar Bio
UB	Top Web - 48	69.8	0.92	221.6	21.9	pdl	0.34	pdl
CSN	gsm 60%				(101)
9/23F	C/40%
	polypropylene
	(against Horn)
	Bottom Web-
	25 gsm
	spunbond
	Eastar Bio
UB	Top Web-20	36.7	0.50	225.3	Nw	pdl	nw	pdl
CSN	gsm spunbond
9/23B-	poly(lactide)
PLA	(against Horn)
	Botton Web-
	11 gsm
	70% C/30%
	Bico
	polypropylene
	Core/Eastar
	Bio Sheath

As illustrated in Table 8, the calender point-bonded CSN Samples “o” and “s” had good strength properties with the cross-machine direction (“CD”) tearing strength values being about 40% greater than the machine direction (“MD”) values.

TABLE 8


Strength Properties of TB CSNs Containing 12 gsm spunbond
polypropylene Substrate with Silicone-based Wettable Concentrate

			Tearing
	Breaking		Strength
Sample	Load	Breaking	(KG)

No.	Description	(KG)	Elongation (%)	MD	CD

“o”	13 gsm 50/50	1.58	53.0	0.16	0.23
	C/polypropylene
	12 gsm spunbond
	polypropylene/6%
	S-1180 (Silicone)
“s”	13 gsm 60/40	1.87	37.7	0.13	0.19
	C/polypropylene
	12 gsm spunbond
	polypropylene/6%
	S-1180 (Silicone)

Likewise, the calender point-bonded CSNs in Table 9 had excellent tearing strength with the cross-machine direction values again being much higher. On the other hand, machine direction breaking load values were more than twice the cross-machine direction values. However, breaking elongations were more similar between meltblown and cross-machine direction, with these values ranging from 51-82%, even without elastomeric components such as meltblown or spunbond EASTAR BIO, are highly extensible.

TABLE 9


Strength Properties of TB CSNs Containing 12 gsm spunbond
polypropylene Substrate with 5% of Two Different Fluorosurfactant (FS)
Concentrates

		Breaking	Tearing
	Breaking	Elongation	Strength
Sample	Load (KG)	(%)	(KG)

No.	Description	MD	CD	MD	CD	MD	CD

D3PP1	13 gsm 50/50 C/polypropylene	1.46	0.77	61.8	74.3	0.34	0.40
	12 gsm spunbond
	polypropylene/5% S-1242
	fluorosurfactant
D3PP2	Same as D3PP1
D4aPP	13 gsm 60/40 C/polypropylene	1.78	0.62	67.8	68.0	0.18	0.30
	12 gsm spunbond
	polypropylene/5% S-1242
	fluorosurfactant
D4bPP	Same as D4aPP	1.68	0.61	62.9	67.6	0.23	0.51
G2aPP	13 gsm 50/50 C/polypropylene
	12 gsm spunbond
	polypropylene/5% S-1243
	fluorosurfactant
G2bPP	Same as G2aPP	1.71	0.58	63.6	65.1	0.21	0.31
G3aPP	13 gsm 60/40 C/polypropylene	1.71	0.73	51.3	73.2	0.20	0.27
	12 gsm spunbond
	polypropylene/5% S-1243
	fluorosurfactant
G3bPP	Same as G3aPP	1.97		62.8		0.19	0.34
G3cPP	Same as G3aPP	1.64		68.9		0.15	0.34
H1PP	36 gsm 50/50 Bealls Gr 1 Gin	1.72	0.71	72.7	82.5	0.30	0.41
	Motes/polypropylene
	12 gsm spunbond polypropylene/
	5% S-1243
	fluorosurfactant

In Table 10, the strength and breaking elongation properties of calender point-bonded CSNs with cotton-blend webs on 25 and 48 gsm spunbond EASTAR BIO are illustrated. As with the CSNs having 12 gsm wettable spunbond polypropylene as the substrate described above, all of the samples in Table 10 had excellent breaking load and tearing strength, and the machine direction breaking loads were greater than the cross-machine direction values, and the cross-machine direction tearing strength values were greater in the cross-machine direction than in the machine direction. However, the breaking elongations were much higher in both machine direction and cross-machine direction directions with the elastic 25 and 48 gsm spunbond EASTAR BIO substrates than with the relatively inelastic 12 gsm spunbond polypropylene webs.

TABLE 10


Strength Properties of Thermally Bonded (TB) CSNs Containing 25 gsm
and 48 gsm spunbond EASTAR BIO Substrate

		Breaking	Tearing
	Breaking	Elongation	Strength
Sample	Load (KG)	(%)	(KG)

No.	Description	MD	CD	MD	CD	MD	CD

D1E	12.5 gsm 70 C/30 Bico	0.49	0.27	88.9	125.4	0.26	0.41
	polypropylene/Eastar
	25 gsm spunbond EASTAR
	BIO
D2aE	11 gsm 60 C/40 Bico	2.93	2.04	133.5	156.6	0.50	0.97
	polypropylene/Eastar
	25 gsm spunbond Eastar Bio
D2bE	Same as D2aE	0.40	0.32	84.7	114.5	0.21	0.43
D3E	22.6 gsm 70 C/30 Bico	0.50	0.29	68.4	119.4	0.21	0.40
	polypropylene/Eastar
	25 gsm spunbond Eastar Bio
E1E	13 gsm 60/40 C/polypropylene	0.59	0.34	60.5	61.7	0.20	0.34
	25 gsm spunbond Eastar Bio
E4E	40 gsm 50 Beals Grade 1	0.60	0.35	89.0	110.5	0.20	0.37
	Cotton Reginned Motes/50
	polypropylene
	25 gsm spunbond Eastar Bio
“ah”	25 gsm	1.42	0.50	99.6	130.5	0.27	0.60
	70 C/30 Bico polypropylene/Eastar
	48 gsm spunbond Eastar Bio

Significant progress was also made in developing the technology for the meltblown and spunbond processing of thermoplastic polyurethanes. During preliminary meltblown trials it was observed that the thermoplastic polyurethane filaments were often traveling horizontally from meltblown die only a few inches or more, depending on air flow rates, before dropping vertically towards the floor. This observation coupled with the fact that relatively large diameter meltblown fibers were being produced led us to believe that we had been going in the wrong direction with respect to spinneret hole diameter and air knife gap. With many high melt viscosity polymers such as polyesters and nylons, a large hole die (0.018 inch hole diameter compared to the standard hole diameter of 0.0145 in.) and larger air knife gap of 0.090 inches actually results in finer fibers and softer webs. However, based on our observations described above, the standard die tip with 0.0145 in. diameter holes and with an L/D of 8.5/1 and a hole density of 25 holes/inch was used. Also, the air knife gap on both sides of the nose tip was reduced to 0.030 in. and the die tip setback to 0.030 in. These innovations enabled us to produce uniform meltblown thermoplastic polyurethane webs with fiber diameters of 5 micrometers, well in the microfiber range (data not shown). [0158]
In an effort to successfully produce spunbond thermoplastic polyurethane, which would enable the production of cotton-surfaced spunbond thermoplastic polyurethane, Noveon, Inc. of Cleveland, Ohio designed two resins, 58283-045 and X-4981-045, which were re-extruded to lower molecular weight, and a filler was added to both resins to minimize sticking of the extruded filaments before quenching. [0159]
Estane 58238-045 was first run on a 1.0 [0160] meter Reicofil 2 spunbond line. Although this thermoplastic polyurethane had a higher melt index than Estane 58280, there were still problems with pressure surges in the extruder and spunbond die at the same die temperature of 380° F. Nevertheless, some thermoplastic polyurethane filaments were processed through the spunbond die to produce some spunbond fabric. The filaments still stuck together forming bundles of filaments, although the sticking problem was not as pronounced as before.
Thermally-point bonded laminates of meltblown and spunbond thermoplastic polyurethane webs produced strong, highly elastic composites with excellent cover factor and barrier performance being provided by the meltblown component with its microfibers. Furthermore, cotton-based webs have been bonded in preliminary trials by this inventor to meltblown thermoplastic polyurethane, spunbond thermoplastic polyurethane and to meltblown/spunbond laminated thermoplastic polyurethane webs to produce strong highly elastic fabrics with cotton on one or both sides for enhanced wear comfort, absorption, and biodegradability of the cotton component. [0161]

Some properties of thermally or ultrasonically bonded CCNs are illustrated in Tables 11-13.

TABLE 11


Strength Properties of Thermally Bonded (TB) CCNs Containing 12 gsm
spunbond polypropylene Substrate with Silicone-based and Fluorosurfactant (FS)
Concentrates

Breaking	Breaking	Tearing
Load	Elongation	Strength
(KG)	(%)	(KG)

Sample No.	Description	MD	CD	MD	CD	MD	CD

TB CCN 9/12A	Top Web- l2 gsm MB	2.86	41.9	0.31	0.44
	polypropylene (against diamond roll)
	Core- 40 gsm 50% Bealls Gr
	1/50% polypropylene
	Bottom Web- 17 gsm spunbond
	polypropylene w 6% S-1180
	(Silicone)
TB CCN 9/12C	Top Web- l2 gsm MB	2.91	48.5	0.32	0.46
	polypropylene (against diamond roll)
	Core- 51 gsm 60% Cotton/
	40% polypropylene Staple
	Bottom Web- 17 gsm spunbond
	polypropylene w 6% S-1180
	(Silicone)
TB CCN 9/12D	Top Web- l2 gsm MB	1.72	49.9	0.43	0.68
	polypropylene (against diamond roll)
	Core- 51 gsm 60% Cotton/
	40% polypropylene Staple
	Bottom Web- 17 gsm spunbond
	polypropylene w
5% S-1243
	fluorosurfactant

TABLE 12


Strength Properties of Ultrasonically Bonded (UB) CCNs Containing
Wettable spunbond Webs and spunbond EASTAR BIO Webs

			Tearing
	Breaking	Breaking	Strength
Sample	Load	Elongation	(KG)

No.	Description	(KG)	(%)	MD	CD

UB	Top Web- 17 gsm spunbond	3.27	73.3	0.29	0.50
CCN	polypropylene w 6% S-1180 (Silicone)
9/23B	against Horn
	Core- 51 gsm 60% C/40%
	polypropylene
	Bottom Web- 27 gsm MB EASTAR BIO
UB	Top Web- 17 gsm spunbond	0.99	73.5	0.59	0.77
CCN	polypropylene w	5% S-1243
9/23C	(Fluorosurfactant) against Horn
	Core- 51 gsm 60% C/40%
	polypropylene
	Bottom Web- 27 gsm MB EASTAR BIO
UB	Top Web- 20 gsm spunbond poly(lactide)	0.54	34.1	0.40	0.71
CCN	against Horn
9/23A-	Core- `44 gsm 70% C/30% Bico
PLA	polypropylene Core/EASTAR BIO
	Sheath
	Bottom Web- 27 gsm MB EASTAR BIO

TABLE 13


Strength Properties of Ultrasonically Bonded (UB) CSNs Containing
Wettable spunbond Webs and spunbond EASTAR BIO Webs

	Breaking	Breaking	Tearing
	Load	Elongation	Strength
Sample	(KG)	(%)	(KG)

No.	Description	MD	CD	MD	CD	MD	CD

UB	Top Web- 48 gsm 60% C/40%	1.22	69.0	0.29	0.73
CSN	polypropylene (against Horn)
9/23E	Bottom Web- 25 gsm spunbond
	EASTAR BIO
UB	Top Web- 48 gsm 60% C/40%	0.23	67.6	0.22	0.49
CSN	polypropylene (against Horn)
9/23F	Bottom Web- 25 gsm spunbond
	EASTAR BIO
UB	Top Web- 20 gsm spunbond	0.49	20.9	0.31	0.42
CSN	poly(lactide) (against Horn)
9/23B-	Botton Web- 11 gsm 70% C/30% Bico
PLA	polypropylene Core/EASTAR BIO
	Sheath

EASTAR BIO meltblown bonded better than did the meltblown polypropylene webs in that the CCN laminates produced with meltblown polypropylene and spunbond polypropylene webs had to be run through the infrared bonding unit twice so that each side could be exposed directly to the infrared radiation. The EASTAR BIO meltblown web resulted in very well bonded laminate in one pass through the infrared unit. In addition to having better infrared thermal bonding performance than meltblown polypropylene and spunbond polypropylene, EASTAR BIO meltblown web resulted in exceptionally good wetting and wicking performance compared to the polypropylene web. Further the EASTAR BIO is completely biodegradable thereby making the composite more biodegradable. Heat-Stretching resulted in higher tearing strength and tenacity of laminates. Heat-Stretching produced webs of softer hand and a greater directional wetting in the machine direction. [0165]
It will be understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated above in order to explain the nature of this invention may be made by those skilled in the art without departing from the principle and scope of the invention as recited in the appended claims. [0166]

Claims

What is claimed is:

1. A method of producing a non-woven composite, comprising:

a. creating a first layer, the first layer comprising a first biodegradable component;

b. creating a second layer, the second layer comprising a biodegradation enhancement component; and

c. bonding the first layer to the second layer.

2. The method of claim 1, wherein:

a. the biodegradable component comprises at least one of (i) a wetting agent or (ii) a hydrophilic biodegradable material

3. The method of claim 1, further comprising:

a. adding a non-elastic thermoplastic component to the biodegradable component in the first layer; and

b. heat-stretching the non-elastic thermoplastic component and the biodegradable component in the machine direction.

4. The method of claim 1, further comprising:

b. heat-stretching the non-elastic thermoplastic component and biodegradable component in the cross-machine direction.

5. The method of claim 1, wherein:

a. the second layer further comprises at least one of (i) a spunbond material or (ii) a meltblown material.

6. The method of claim 5, wherein:

a. a wetting agent is added topically to the spunbond material.

7. The method of claim 1, further comprising:

a. creating a third layer, the third layer comprising a nonbiodegradable component; and

b. bonding the first layer to the third layer;

c. wherein the third layer is on a side of the first layer opposite the second layer.

8. A non-woven composite, comprising:

a. a first layer, further comprising a biodegradable component; and

b. a second layer, further comprising a biodegradation enhancement component, the second layer being bonded to the first layer.

9. The non-woven composite of claim 8, wherein:

a. the biodegradation enhancement component is at least one of (i) a wetting agent or (ii) a hydrophilic biodegradable material.

10. The non-woven composite of claim 9, wherein:

a. the wetting agent makes the non-woven composite more wettable.

11. The non-woven composite of claim 8, wherein:

a. the second layer is bonded to the first layer using at least one of (i) calender patterned bonding, (ii) ultrasonic patterned bonding, (iii) infrared bonding, or (iv) hot air bonding.

12. The non-woven composite of claim 8, wherein:

a. the second layer comprises at least one of (i) a spunbond non-woven material or (ii) a meltblown non-woven material.

13. The non-woven composite of claim 8, wherein:

a. the first layer further comprises a thermoplastic biodegradable fiber, the thermoplastic biodegradable fiber further comprising at least one of (i) EASTAR BIO, (ii) poly(lactide), (iii) polyvinyl alcohol, (iv) other biodegradable fibers, or (v) a bicomponent fiber with biodegradable components.

14. The non-woven composite of claim 8, further comprising:

a. a third layer;

b. wherein:

i. the second layer comprises a meltblown layer bonded on a first outer surface of the first layer; and

ii. the third layer comprises a spunbond layer bonded to a second outer surface of the first layer disposed opposite the first outer surface.

15. The non-woven composite of claim 14, wherein:

a. the first layer further comprises a cellulosic fiber blended with a thermoplastic fiber, the thermoplastic fiber further comprising at least one of (i) polyethylene, (ii) polypropylene, (iii) polyester, (iv) nylon, (v) low melting point fibers, or (vi) bicomponent fibers; and

b. at least one of the outer spunbond or meltblown layers comprise a biodegradable polymer, the biodegradable polymer further comprising at least one of (i) poly(lactide), (ii) EASTAR BIO, (iii) polyvinyl alcohol, or (iv) other biodegradable polymers.