JP2003520307A - Nonwoven laminated wipe product and method of manufacturing the same - Google Patents

Abstract

  (57) [Summary] A nonwoven laminated product comprising a fine denier base web of thermoplastic material bonded to a bulk layer and a method of making the same. The bulk layer is preferably a cellulose material, more preferably wood pulp. Nonwoven laminated products have improved strength, flexibility, and drape properties when compared to conventional nonwoven laminated products.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION The present invention relates generally to nonwoven laminated products. More specifically, the present invention relates to nonwoven laminated products having a fine denier per filament.

As used herein, the term “nonwoven laminated product” refers to polymeric fibers or filaments produced by extrusion and a nonwoven “bulk” layer bonded thereto, preferably a nonwoven “bulk” layer of cellulosic material. A multi-layer product having a non-woven "substrate" layer. The term "nonwoven laminated product" as used herein excludes multiphase materials such as those described in U.S. Pat. No. 2,414,833, in which both the phases and layers are deposited on the stomatal member by dispersion.

The nonwoven laminated product of the present invention can be cut into individual wipe sheets. While the sheets can be used dry, the individual sheets are typically dipped into a chemical solution suitable for the intended end use, stacked, and packaged in a liquid tight container for later distribution. Chemical solutions often contain germicides and other biocontrol agents as well as emulsifiers, pH buffers, perfumes and the like. The liquid-tight container keeps the wiping sheet saturated.

Such wipes, called wet wipes or simply wipes, are commonly used by consumers for cleaning or wiping, especially when wash water is not readily available or conveniently available. Has been. Such wipes are very convenient for travelers and parents of small children. Such wipes have been used for make-up and makeup removers, for cleaning body parts, and as an alternative to conventional dry toilet paper. The wipes are also useful for household and industrial cleaning.

Current non-woven laminated products have strength, flexibility, lotion distribution, cleanability, purity (ie, no binder added) in product applications such as baby wipes.
It has provided consumers with the marketability of various desired characteristics, such as. Of course, these pre-moistened wipes must also have sufficient wet strength to withstand the tearing and puncture that occurs during heavy use in wet conditions. While existing products have been well received by consumers, there is a desire to improve the strength, flexibility, and thickness of such existing products.

Definitions Composite fiber-A fiber formed from at least two polymers from a single filament formed from different extruders through a single spinneret hole. The polymer is
It is located in a well-defined area at a substantially constant position within the cross section of the conjugate fiber and extends continuously over the entire length of the conjugate fiber. The configuration of such a bicomponent fiber is, for example, a core-sheath arrangement or parallel arrangement in which one polymer is surrounded by another polymer.

Mixed Fiber-A fiber formed from a mixture of two or more polymers extruded from the same spinneret. Mixed fibers do not have different polymer components arranged in well-defined areas that are relatively constant in the cross section of the fiber, and the different polymers are usually not continuous over the entire length of the fiber, Instead, they form fibrils that usually start and end in a chaotic manner.

Cellulose Fiber-A cellulosic fiber from natural sources such as wood and non-wood plants. Wood plants include, for example, deciduous and coniferous trees. Non-timber plants include, for example, cotton, flax, African hemlock, sisal, Manila hemp, milkweed, straw, jute, hemp, and bagasse.

[0009]   Transverse direction (CD) -the direction perpendicular to the longitudinal direction.

Denier-A unit used to describe the weave of filaments. This unit is expressed as the mass of the filament divided by its length. 1 denier filament has a length of 9
It has a mass of 1 gram per 000 meters.

[0011]   Machine Direction (MD) -The direction of travel of the forming surface on which fibers are deposited during formation of the nonwoven web.

[0012] Meltblown fibers-A molten thermoplastic material is extruded as filaments from a plurality of fine, usually circular die capillaries into a high velocity gas (eg, air) stream, thereby determining the diameter of the filaments of molten thermoplastic material. Fiber formed by reducing. Thereafter, the meltblown fibers are carried in a high velocity gas stream and deposited on the collecting surface to form a web in which the meltblown fibers are randomly dispersed. Meltblown fibers are generally discontinuous. The melt blown method includes a melt spray method.

[0013]   Non-thermoplastic-any substance that does not fall within the definition of thermoplastic.

Nonwoven fibers or webs-webs in which individual fibers are stacked but have a structure that is not identical to the method in knitting. Nonwoven fibers or webs are formed from a number of methods including, for example, meltblowing, spunbonding and wet or dry lamination. The basis weight of non-woven fibers is expressed in grams per square meter (gsm),
Fiber weave is measured in denier.

Polymers-generally includes polymers such as copolymers such as block, graft, random and alternating copolymers, terpolymers, and mixtures and variations thereof. Further, unless otherwise specifically limited, “polymer” includes all possible geometric arrangements of materials. These configurations include isotactic, syndiotactic and random symmetry.

Spun filaments or fibers-Filaments formed by extruding a molten thermoplastic material from a plurality of fine, usually circular, spinneret capillaries. The diameter of the extruded filament is then rapidly reduced, for example by drawing and / or known mechanisms. The whole spun filament is continuous,
The maximum value in the denier range is about 5 or more.

Thermoplastic-A polymer that is fusible and softens when exposed to heat and returns to its normally non-softened state when cooled to room temperature. Thermoplastics are, for example, polyvinyl chloride, some of the polyesters, polyamides, polyfluorocarbons, polyolefins, some of the polyurethanes, polystyrene, polyvinyl alcohol, caprolactam, copolymers of ethylene with at least one vinyl monomer (for example poly ( Ethylene vinyl acetate)), and acrylic resin.

SUMMARY OF THE INVENTION Briefly, one aspect of the invention in its preferred form comprises a bulk layer predominantly composed of cellulosic fibers or pulp bonded to a substrate web of extruded fine denier fibers. It is a non-woven laminated or composite product. The layers are preferably joined by hydroentanglement. The "fine denier" substrate web fiber has a denier of 1.5 or less,
It preferably has a denier of 1.2 or less, and more preferably a denier in the range of 0.5 to 1.2. The basis weight of the nonwoven laminated product of the present invention is preferably 100 gs.
It is less than m, and more preferably in the range of 35 to 75 gsm.

The base web fiber is made of an extruded material such as polyolefin (eg, polyethylene / polypropylene), polyester, rayon, tencel, acetate, and acrylic. The base web fiber is preferably extruded from a thermoplastic polymer. The substrate web is more preferably a layer of spun or bonded substantially continuous filaments of a material selected from the group consisting of polyolefins, polyesters, and polyethylene / polypropylene composites and polyethylene / polyester composites. Consists of. The composite filaments are preferably in a low melting sheath or high melting core arrangement.

The basis weight of the substrate web is preferably less than 25 gsm, more preferably 9
Is in the range of up to 20 gsm. The basis weight of the substrate web is preferably between 20 and 60% of the basis weight of the resulting laminated product.

The bulk layer can consist of cellulose fibers, cellulose pulp, synthetic or other artificial fibers or composites of the above. The bulk layer preferably comprises cellulose fibers, more preferably wood pulp. The basis weight of the bulk layer is preferably between 40 and 80% of the basis weight of the resulting nonwoven laminated product.

Another aspect of the present invention is a preferred method of making the nonwoven laminated product of the present invention comprising providing a substrate web of fine denier fibers on a forming wire or conveyor. The substrate web is preferably preformed and placed on a conveyor. Alternatively, the substrate web may be extruded directly onto the conveyor. The bulk layer is deposited on the substrate web. The bulk layer can be deposited, for example, by wet laying or air laying. It is also possible to deposit the bulk layer as a preformed texture. The resulting fine denier substrate web covered with the bulk layer can optionally be passed under a compaction roll. The substrate web / bulk layer composite is entangled with or without consolidation, preferably by passing under a series of hydroentanglement nozzles. The water jet ejected from the nozzle impinges on the bonded web material and hydraulically entangles the bulk layer fibers or pulp with the substrate web. The hydroentangled wet laminate is placed under vacuum to remove most of the water. The semi-dried laminated sheet material is preferably subjected to further heat drying operations to further remove residual water, after which the resulting nonwoven laminated product is wound into rolls for subsequent handling.

The non-woven laminated product of the present invention offers considerable advantages. The fine denier spunbond substrate web serves to provide a softer, drapeable, nonwoven laminate product with a smoother surface than conventional nonwoven laminate products using higher denier substrate webs. The improved softness, drape, and surface smoothness of the nonwoven laminated products of the present invention provide significant advantages in the end consumer market. In addition, the plastic content obtained by the substrate web serves to facilitate embossing of the handle into the final product, thereby increasing consumer appeal.

Despite providing greater softness and smoothness, the nonwoven laminate products of the present invention are comparable to conventional nonwoven laminate products having similar basis weight but higher denier substrate webs. By comparison, it has a surprisingly high tensile and burst strength. The improved strength of the laminated product of the present invention is beneficial in subsequent manufacturing steps, in dispensing finished finished products such as baby wipes from storage containers, and in the use of baby wipes, due to improved burst strength. "Perforated" that occurs when using conventional non-woven laminated wipes
Is significantly reduced. Bulk layers provide a very useful surface in end uses such as cleaning, and help reduce manufacturing costs by substituting less expensive cellulosic fibers for more expensive synthetic fibers. Furthermore, a suitable wood pulp material,
In particular, the air-laid product increases the thickness of the resulting nonwoven laminated product.

It is an object of the present invention to provide non-woven laminated products with enhanced properties of strength and flexibility.

Another object of the present invention is to provide a nonwoven laminate product having higher tensile and burst strength than conventional nonwoven laminate products.

[0027] Yet another object of the present invention is to provide an improved method of making a nonwoven laminate product having higher tensile and burst strengths as compared to conventional nonwoven laminate products.

The present invention is illustrated by the following detailed disclosure of desired functions, properties, features and element relationships, and steps, with each other as illustrated in the description and illustrated embodiments. , Will be better understood.

Detailed Description of the Preferred Embodiments A preferred embodiment of the present invention comprises a non-woven substrate web comprised of fine denier fibers bonded to a bulk layer to form the non-woven laminated product of the present invention. . The invention does not exclude additional layers. The basis weight of the resulting nonwoven laminated product of the present invention is preferably 100 gsm.
Less, more preferably about 35-75 gsm.

The nonwoven substrate web consists of extruded and bonded fine denier fibers. As used herein, "fine" denier filaments or fibers have a denier of 1.5 or less, more preferably 1.2 or less, most preferably 0.5 to 1.2. Have. Nonwoven substrate web fibers consist of extruded materials such as polyolefins (eg polyethylene / polypropylene), polyester, rayon, tencel, acetate, and acrylics, for example. The base web fiber is preferably extruded from a thermoplastic polymer.

The substrate web is more preferably a span and bonded substantially continuous filaments. The substrate web filaments are preferably polyolefins, polyesters, and polyethylene / polypropylene composites, and polyethylene / polypropylene
The material is at least one selected from the group consisting of polyester composites.
If present, the composite filaments preferably take the form of a low melting point sheath and a high melting point core.

The type of bond of the substrate web material is not considered critical, and may include, for example, solvents,
It can include adhesives, needles, hydroentanglements, or thermal bonds. The base web component is
It preferably has a basis weight of less than 25 gsm. More preferably, the substrate web has a basis weight in the range of 9-20 gsm. The substrate web component is preferably between 20 and 60% of the basis weight of the resulting nonwoven laminated product.

The bulk layer generally consists of a cellulosic material. More preferably, the bulk layer is cellulose pulp and most preferably the bulk layer is wood pulp. It is also possible to use mixtures of various cellulose fibers and pulps. The bulk layer can include up to 25% synthetic or other artificial materials such as rayon, tencel, polyester, polyolefins, polyamides, and composites, depending on the desired resulting bulk layer properties. The bulk layer preferably has a basis weight of less than 75 gsm, more preferably in the range of 25-60 gsm. The bulk layer is preferably between 40 and 80% of the basis weight of the resulting nonwoven laminated product.

A preferred method of making the nonwoven laminated product of the present invention comprises providing a spunbonded web of substantially continuous fine denier filaments on a stomatal conveyor. Heat treating the filaments directly on the conveyor is within the scope of the invention, but it is preferred that the fine denier spunbond substrate web be preformed. The cellulosic material can be deposited on a fine denier substrate web to form a bulk layer. The cellulosic material can be deposited on a substrate web that is dispersed either in liquid (wet laying) or in air (air laying). It is also possible to deposit the bulk layer as a preformed texture on the substrate web. It should be noted that the deposition of cellulosic material on a conveyor or papermaking machine and the placement of spunbonded substrate webs on a bulk cellulose layer is fully understood by the present invention. Optionally, the substrate web with the deposited bulk layer passes under a consolidation roll.

The substrate web having the deposited bulk layer is hydroentangled to provide a laminated sheet having desired tactile, adsorptive, and strength properties. Preferably, the hydroentanglement step is performed before the drying operation. Typically, the hydroentanglement operation is a low to intermediate pressure hydroentanglement operation, as disclosed in US Pat. No. 5,151,320 by Homonoff et al., Incorporated herein by reference. While the Homonov et al. Patent relates to non-woven web materials different from the present invention, the hydroentanglement operation described therein can also be effectively used in the present invention. That is, the hydroentanglement process preferably applies a large amount of liquid jet to the fibers of the bulk layer with sufficient force to eject some of the fibers into the substrate web layer to cause hydroentanglement. The liquid jet is preferably an aqueous jet. The hydroentanglement process is about 0.1-0.4 per pound of web.
It can be done on a conveyor with the total energy input at horsepower (Hp-hr / lb). It should be appreciated that energy inputs of 0.4 Hp-hr / lb and above can be used in the practice of the invention.

The hydroentangled wet laminate is placed under vacuum to remove most of the water. The semi-dried laminated sheet material is further subjected to a conventional heat drying operation such as a heat drying can to further remove water. The drying process and temperature are controlled to achieve the desired thermoplastic fiber melting level. As an example, a nonwoven laminated product with a polyolefin-based web has a drying temperature of about 100 ° C. After the finished nonwoven laminated product is dried, it is wound into rolls for subsequent handling, shipping and production of the final product.

The nonwoven laminate product of the present invention exhibits surprisingly high tensile strength in both wet and dry conditions when compared to conventional web materials of similar basis weight with higher denier substrate webs. The tensile test used here is 1 inch in width (about 25 mm) and 5 in length.
Perform on inch (about 125 mm) samples. Place the sample in the jaws of the tensile tester. Suitable tensile testers are available from Instron and Zwick. The tensile tester applies a constant elongation of 5 inches per minute until the test sample fails. A load cell is used to measure the force exerted on the sample during breakage. The force required to break a test sample is 25 grams.
It is displayed in grams per mm (g / 25 mm). For the wet tensile test, the sample is immersed in water at room temperature. After dipping, the sample is absorbed on absorbent cotton to remove excess water. Tensile strength can also be expressed as total tensile strength, which is the sum of MD and CD tensile strengths.

The nonwoven laminate products of the present invention exhibit even more surprising breaking strength, especially in wet conditions, when compared to similar web weight conventional web materials with larger denier substrate webs. The breakage test used here is performed according to ASTM D3786.

Having provided a general description of the invention, the following examples are included for purposes of illustrating the invention more readily, and are meant to limit the scope of the invention unless specifically indicated. Not a thing. All parts are given by dry weight unless otherwise indicated.

Example 1 Four non-woven laminated products (Samples 1-4) were prepared generally according to the method described above.
In all samples, the substrate web consisted of spun and bonded substantially continuous polypropylene filaments. Corsnas (Kor) in all samples
snaes) treated wood pulp was air laid on each substrate web. The resulting laminated material was hydroentangled and dried using vacuum and heat as before.

Samples 1 and 2 consisted of a conventional nonwoven laminated product having a spunbonded substrate web with filaments having an average denier of about 2.2. Sample 3
And 4 consisted of a non-woven laminated product having a fine denier spunbonded substrate web with filaments having an average denier of less than 1.2.

The base web of Sample 3 and 4, the total laminate basis weight of 74 g / ^{m 2} obtained about 2
It was 5%. Sample 2 had a similar base web to wood pulp fiber ratio as Samples 3 and 4, while the base web of Sample 1 contained slightly more wood pulp. The basis weight of the resulting laminated product was slightly higher for sample 2, than samples 1, 3, and 4, and samples 1, 3, and 4 were similar. Dry and wet tensile strength tests were conducted in the machine direction (MD), transverse direction (CD) and total tensile strength for the samples. The samples were also tested for wet Mullen burst strength. The properties of Samples 1 to 4 are summarized in Table 1.

[0043]

[Table 1] The fine denier substrate webs of Samples 3 and 4 are much softer and smoother and more drapeable than the conventional high denier substrate webs of Samples 1 and 2. The improved softness, surface smoothness, and drapability of the fine denier substrate webs of Samples 3 and 4 obtained with the present invention compared to conventional non-woven laminated products represented by Samples 1 and 2. Non-woven laminated products for greater flexibility, drape,
And play a role in providing surface smoothness.

As can be further seen from Table 1, the nonwoven laminated products of the present invention (Samples 3 and 4)
Both show significantly increased tensile strength compared to conventional samples 1 and 2. This increase was obtained both under wet and dry conditions, as well as in the machine direction (MD) and the transverse direction (CD). Also, the nonwoven laminated products of the present invention (Samples 3 and 4) both exhibit significantly increased burst strength compared to conventional Samples 1 and 2. Given the fine denier of the base web fibers of the present invention and the improved flexibility, drape, and surface smoothness of the resulting nonwoven laminated products, the improved tensile and burst strengths are surprising and surprising. To have.

Furthermore, both the nonwoven laminate products of the present invention (Samples 3 and 4) had higher surface area and higher web uniformity as compared to the conventional Sample 1 and 2 nonwoven laminate products. The high homogeneity of both non-woven laminated products of the present invention (Samples 3 and 4) makes them more attractive in appearance as a wiped product and has a higher quality image as compared to conventional non-woven laminated products. Was decided to draw. It should be noted that these benefits are obtained while maintaining a basis weight that is substantially the same as or less than conventional products. In fact, the use of a substrate web having filaments with a denier of about 2.2 or more has undesirable "stains" in the final nonwoven laminated product.
Is known to bring some.

While the preferred embodiments of the above invention have been set forth for purposes of illustration, the above description should not be construed as a limitation of the invention. Thus, various modifications, adaptations, and alternatives can be made by those skilled in the art without departing from the spirit and scope of the invention.

─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Richard B. Anise             Connecticut State 06074, USA,             South Windsor, Sandston Dora             Eve 910 (72) Inventor Stanley M. Griskiwich             Connecticut State 06010, USA,             Bristol, Breaksley Street             −159, 200 F-term (reference) 4F100 AJ06B AK01A AK04A AK07A                       AK41A AK64A BA02 DG02B                       DG04A DG06B DG15B DG20A                       EC092 EJ192 GB15A GB71                       GB90 JA13A JB16A JK02                       JK03 JK13 JK15 YY00A                 4L047 AA12 AA14 AA17 AA21 AA27                       AB03 AB06 AB07 BA04 BA09                       CA07 CB01 CB10

Claims (20)

[Claims] 1. A tensile strength reinforced composite non-woven material comprising a non-woven substrate web, the thermoplastic fiber having a maximum denier of 1.5 and covering the surface of the non-woven substrate web and being dense with the non-woven substrate web. A composite nonwoven material having an additional layer entangled with. 2. The material of claim 1, wherein the thermoplastic fiber is 0.5
A material characterized by having a denier in the range of 1.2. 3. The material according to claim 1, wherein the thermoplastic fiber is made of a material selected from at least one selected from the group consisting of polyolefin, propylene, polyester, polyethylene / polypropylene and polyethylene / polyester. And the material. 4. The material of claim 1, wherein the thermoplastic fiber is a substantially continuous span of material selected from the group consisting of polyolefins, polyesters, polyethylene / polypropylene and polyethylene / polyester. A material characterized by being a filament. 5. The material according to claim 1, wherein the additional layer is a bulk layer. 6. The material of claim 1, wherein the additional layer is a bulk layer of cellulosic material. 7. The material according to claim 1, wherein the additional layer is a bulk layer made of wood pulp. 8. The material of claim 1, having a basis weight, wherein the substrate web is 20-60% of the basis weight. 9. Material according to claim 1, characterized in that it has a basis weight of less than 100 g / m ² . 10. Material according to claim 1, characterized in that it has a basis weight in the range 35-75 g / m ² . 11. The material according to claim 1, wherein the base material web is 25 g.
A material having a basis weight of less than / m ² . 12. The material of claim 1, wherein the substrate web is 9-2.
A material having a basis weight in the range of 0 g / m ² . 13. A method of making a composite nonwoven material having enhanced tensile and burst strength, the method comprising providing a nonwoven substrate web comprising thermoplastic fibers having a maximum denier of 1.5. A method comprising: providing a layer adjacent to a substrate web; and interlacing the adjacent layer with the substrate web to form a composite nonwoven material. 14. The method of claim 13, wherein the adjacent layer is provided in a substantially dry form. 15. The method of claim 13, wherein the adjacent layer is provided as a predetermined layer of nonwoven cellulosic web material. 16. The method according to claim 13, wherein the confounding step comprises:
A method comprising hydroentanglement and further comprising the step of drying the hydroentangled composite nonwoven material. 17. The method of claim 13, further comprising consolidating the substrate web and adjacent layers. 18. The method of claim 13, wherein the step of providing the nonwoven substrate web comprises spunbonding a thermoplastic material. 19. A non-woven wipe material having a non-woven substrate web suitable for wet use, the thermoplastic fiber having a maximum denier of 1.5 and a cellulosic material intimately entangled with the web substrate. And a nonwoven wipe having a tensile strength of at least 1.5 times that of a similar nonwoven wipe having a base web of filaments having a greater denier. Wiping material. 20. The wet wipe of claim 19 having at least twice the wet tensile strength of a similar nonwoven wipe having a base web of filaments having a higher denier. Wet wiping material characterized by: