Method for manufacturing coformed nonwoven web

Abstract

Various embodiments include methods of making a nonwoven web having a substantially uniform structure. The method includes providing a stream of secondary fibrous material, providing a stream of meltblown fibrous material, and providing a stream of softener. The stream of secondary fibrous material, the stream of meltblown fibrous material, and the stream of softener are combined to form a composite stream. The composite flow is deposited onto a forming surface to form the composite flow into a nonwoven web.

Description

Background Art

[0001] Nonwoven webs, sometimes referred to as coform webs, formed as a composite of a meltblown thermoplastic fiber matrix and a secondary fiber material have been used as absorbent layers in a variety of applications, including absorbent articles, absorbent dry wipes, absorbent wet wipes, and mops. However, there is a continuing need to improve the softness and strength characteristics of coform webs. Additionally, there is a continuing need to increase the efficiency of coform web manufacturing, including by reducing material usage and / or waste. Summary of the Invention

[0002] Some of the aspects of the present disclosure relate to a method of making a nonwoven web having a substantially uniform structure, the method comprising: providing at least one stream of a secondary fibrous material; providing at least one stream of a meltblown fibrous material; providing at least one stream of a softening agent; combining the at least one stream of the secondary fibrous material, the at least one stream of the meltblown fibrous material, and the at least one stream of the softening agent to form a composite stream comprising the secondary fibrous material, the meltblown fibrous material, and the softening agent; and depositing the composite stream onto a forming surface to form the nonwoven web.

[0003] In some aspects, in addition to or instead of any of the preceding aspects, combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: combining the at least one stream of secondary fibrous material and the at least one stream of softening agent to form a mixed stream consisting of the secondary fibrous material and the softening agent; and subsequently combining the mixed stream with the at least one stream of meltblown fibrous material to form the composite stream.

[0004] In some aspects, in addition to or instead of any of the preceding aspects, combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: combining the at least one stream of meltblown fibrous material and the at least one stream of softening agent to form a mixed stream consisting of meltblown fibrous material and softening agent; and subsequently combining the mixed stream with the stream of secondary fibrous material to form the composite stream.

[0005] In some aspects, in addition to or instead of any of the preceding aspects, the at least one stream of meltblown fibrous material includes a first stream of meltblown fibrous material and a second stream of meltblown fibrous material, such that combining the at least one stream of meltblown fibrous material and the at least one stream of softening agent to form the mixed stream includes combining the first stream of meltblown fibrous material and the at least one stream of softening agent to form the mixed stream, the method further comprising combining the second stream of meltblown fibrous material with the mixed stream and the stream of the secondary fibrous material to form the composite stream.

[0006] In some aspects, in addition to or instead of any of the preceding aspects, combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent in a forming zone to form the composite stream.

[0007] In some aspects, in addition to or instead of any of the preceding aspects, combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: combining the at least one stream of secondary fibrous material and the at least one stream of meltblown fibrous material to form a mixed stream consisting of secondary fibrous material and meltblown fibrous material; and subsequently combining the mixed stream with the at least one stream of softening agent to form the composite stream.

[0008] In some aspects, in addition to or instead of any of the foregoing aspects, the meltblown fiber material comprises a polymer.

[0009] In some aspects, in addition to or instead of any of the preceding aspects, the polymer comprises polypropylene or polyethylene.

[0010] In some aspects, in addition to or instead of any of the foregoing aspects, the secondary fibrous material comprises wood pulp.

[0011] In some aspects, in addition to or instead of any of the foregoing aspects, the softener comprises silicone.

[0012] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is in a range from 20 / 80 to 60 / 40.

[0013] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is in a range from 25 / 75 to 40 / 60.

[0014] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is 30 / 70.

[0015] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of softening agent to secondary fiber material in the nonwoven web is in a range from 20 lb / MT to 80 lb / MT.

[0016] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of softening agent to secondary fiber material in the nonwoven web is 40 lb / MT.

[0017] In some aspects, in addition to or instead of any of the foregoing aspects, the nonwoven web has a TS7 value of less than 7.0.

[0018] In some aspects, in addition to or instead of any of the foregoing aspects, the nonwoven web has a TS7 value of less than 6.0.

[0019] In some aspects, in addition to or instead of any of the foregoing aspects, the nonwoven web has a TS7 value of less than 5.0.

[0020] Some aspects of the present disclosure relate to a method of making a nonwoven web having a substantially uniform structure, the method comprising: providing a mat of a secondary fibrous material treated with a softening agent; combing the mat of secondary fibrous material to form at least one mixed stream comprising the secondary fibrous material and the softening agent; providing at least one stream of meltblown fibrous material; combining the at least one stream of meltblown fibrous material with the at least one mixed stream to form a composite stream comprising the secondary fibrous material, the meltblown fibrous material and the softening agent; and depositing the composite stream onto a forming surface to form a nonwoven web.

[0021] In some aspects, in addition to or instead of any of the preceding aspects, providing a mat of secondary fibrous material treated with a softening agent comprises: providing the mat of secondary fibrous material; and combining a stream of softening agent with the mat of secondary fibrous material.

[0022] In some aspects, in addition to or instead of any of the foregoing aspects, providing a mat of secondary fibrous material treated with a softening agent comprises: providing the secondary fibrous material; combining a stream of softening agent with the secondary fibrous material; and forming the combined secondary fibrous material and softening agent into the mat of secondary fibrous material treated with softening agent.

[0023] In some aspects, in addition to or in lieu of any of the foregoing aspects, the mat of secondary fibrous material comprises a first mat of secondary fibrous material, the method further comprising: providing a second mat of secondary fibrous material; and combing the second mat of secondary fibrous material with the first mat of secondary fibrous material to form a mixed stream of the secondary fibrous material and the softener.

[0024] In some aspects, in addition to or in lieu of any of the foregoing aspects, the method further comprises providing a third pad of secondary fibrous material, the first pad of secondary fibrous material disposed between the second pad of secondary fibrous material and the third pad of secondary fibrous material; and combing the first pad of secondary fibrous material, the second pad of secondary fibrous material, and the third pad of secondary fibrous material to form a mixed stream of the secondary fibrous material and the softener.

[0025] In some aspects, in addition to or instead of any of the foregoing aspects, the meltblown fiber material comprises a polymer.

[0026] In some aspects, in addition to or instead of any of the preceding aspects, the polymer comprises polypropylene or polyethylene.

[0027] In some aspects, in addition to or instead of any of the foregoing aspects, the fibrous material comprises wood pulp.

[0028] In some aspects, in addition to or instead of any of the foregoing aspects, the softener comprises silicone.

[0029] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is in a range from 20 / 80 to 60 / 40.

[0030] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is in a range from 25 / 75 to 40 / 60.

[0031] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is 30 / 70.

[0032] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of softening agent to secondary fiber material in the nonwoven web is in a range from 20 lb / MT to 80 lb / MT.

[0033] In some aspects, in addition to or instead of any of the foregoing aspects, the weight ratio of softening agent to secondary fiber material in the nonwoven web is 40 lb / MT.

[0034] In some aspects, in addition to or instead of any of the foregoing aspects, the nonwoven web has a TS7 value of less than 7.0.

[0035] In some aspects, in addition to or instead of any of the foregoing aspects, the nonwoven web has a TS7 value of less than 6.0.

[0036] In some aspects, in addition to or instead of any of the foregoing aspects, the nonwoven web has a TS7 value of less than 5.0.

[0037] Additional aspects of the present disclosure will be set forth in part in the detailed description, drawings, and claims that follow, and in part will be derived from the detailed description, or may be learned by practice of the present disclosure. It should be understood that both the foregoing general description and the following detailed description are exemplary and illustrative only and do not limit the disclosed disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] There are disclosed in the drawings example features and implementations. However, the disclosure is not limited to the precise arrangements and instrumentalities shown.

[0039] Figure 1 is a schematic diagram of an example cross-section of a nonwoven web according to aspects of the present disclosure.

[0040] Figure 2is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to one embodiment of the present disclosure.

[0041] Figure 3 is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to another embodiment of the present disclosure.

[0042] Figure 4 is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to another embodiment of the present disclosure.

[0043] Figure 5 is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to another embodiment of the present disclosure.

[0044] Figure 6 is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to another embodiment of the present disclosure.

[0045] Figure 7 is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to another embodiment of the present disclosure.

[0046] Figure 8 is a schematic diagram of an apparatus that can be used to produce a fibrous nonwoven web structure according to another embodiment of the present disclosure.

[0047] Figure 9 yes Figures 2 to 8 Schematic diagram of some of the coform features present in the device shown. DETAILED DESCRIPTION

[0048] Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are shown below. Each example is provided by way of explanation and not limitation. In view of this disclosure, it will be apparent to those skilled in the art that various modifications and variations may be made to the various embodiments described herein without departing from the scope or spirit of the present disclosure.

[0049] As used herein, the term "nonwoven fabric or web" means a web having a structure of individual fibers or threads that are sandwiched but not in a regular or identifiable manner (as in a knitted fabric). The term also includes foams and films that have been fibrillated, apertured, or otherwise treated to impart fabric-like properties. Nonwoven fabrics or webs have been formed by many processes, for example, meltblown processes, spunbond processes, hydroentangled processes, and bonded carded web processes. The basis weight of nonwoven fabrics is typically expressed in ounces of material per square yard (osy) or grams per square meter (gsm), while the fiber diameter is typically expressed in μm.

[0050] As used herein, the term "microfiber" means a small diameter fiber having an average diameter of no greater than about 75 μm, for example, an average diameter of about 0.5 μm to about 50 μm, or more specifically, an average diameter of about 2 μm to about 40 μm. Another commonly used expression of fiber diameter is denier, which is defined as the grams per 9,000 meters of fiber and can be calculated by multiplying the fiber diameter in μm squared by the density in grams / cc by 0.00707. Lower deniers indicate thinner fibers, and higher deniers indicate thicker or heavier fibers. For example, a polypropylene fiber diameter given as 15 μm can be converted to denier by squaring, multiplying the result by 0.89 g / cc, and multiplying by 0.00707. Thus, the denier of a 15 μm polypropylene fiber is about 1.42 (152×0.89×0.00707=1.415). Outside the United States, the unit of measurement is more commonly "tex," which is defined as grams per kilometer of fiber. Tex can be calculated as denier / 9.

[0051] As used herein, the term "meltblown fibrous material" means fibers formed by extruding molten thermoplastic material through a plurality of generally circular, fine die capillaries in the form of molten strands or filaments into a converging high-velocity gas (e.g., a gas stream) that attenuates the filaments of molten thermoplastic material to reduce their diameter, which may be a microfiber diameter. Thereafter, the meltblown fibrous material is carried by the high-velocity gas stream and deposited onto a forming surface, which is a collecting surface, to form a web composed of randomly dispersed meltblown fibrous material. Meltblown fibrous material is microfiber that may be continuous or discontinuous and typically has an average diameter of less than 10 μm.

[0052] The apparatus, systems, and methods disclosed herein provide nonwoven web materials that can be used in various applications, including wet wipe products. In various embodiments, the nonwoven web material includes a softening agent that is added during the manufacture of the web (e.g., by coforming). The addition of the softening agent during manufacture improves the softness properties of the nonwoven web material.

[0053] In various embodiments, nonwoven web materials can be used as substrates in wet wipe products. The wet wipe product comprises an absorbent substrate and a liquid formulation absorbed into the substrate. The liquid formulation can include various chemicals, such as preservatives and fragrances diluted (e.g., in water). The wet wipe product can be converted by applying the liquid formulation chemical substances to the absorbent substrate. The liquid formulation for the wet wipe product should remain stable, which may limit the formulation chemicals applicable to the wet wipe. For example, when the liquid formulation includes a softener, the remaining chemicals in the formulation should be selected so that when mixed with the softener, the resulting liquid formulation remains stable.

[0054] As disclosed herein, applying functional chemicals (e.g., softeners) in the substrate forming process has several advantages, including improved substrate softness, improved substrate retention and other improved substrate properties. In certain embodiments, when a softener is added to a substrate in a forming process and then the substrate is used to form a wet wipe product, a wider range of liquid formulations can be added to the substrate. For example, in certain embodiments, the improved softness of the substrate can make the liquid formulation free of softeners, which is conducive to using a wider range of functional chemicals (e.g., chemicals that would otherwise damage the stability of the liquid formulation if included with a softener) while maintaining the stability of the liquid formulation. Therefore, various embodiments of the apparatus, system, and method disclosed herein provide more flexible options for producing wet wipes and other nonwoven web materials with various liquid formulation chemicals, which results in improved characteristics (e.g., softness, gentleness, and strength) that consumers expect in wet wipe products. Additionally, as described herein, various embodiments can achieve more efficient manufacturing of nonwoven web materials and wet wipe products made of the nonwoven web materials. As discussed herein, when a nonwoven web is used as a substrate in a wet wipe product, applying the functional chemicals during the web formation process can enable greater flexibility in the liquid formulations used in the wet wipe product (e.g., compared to applying the functional chemicals to the formed substrate via wet application during a converting process).

[0055] Nonwoven web structure

[0056] According to various embodiments, a nonwoven web material (also referred to as a "coform web" or "nonwoven coform web") that combines a meltblown fiber material and a secondary fiber material is disclosed. As discussed in more detail herein, the nonwoven web material can be made using a coform process in which the meltblown fiber material is mixed with the secondary fiber material. In the mixture, a plurality of the secondary fiber material fibers join at least some of the meltblown fiber material fibers to separate the meltblown fibers. The mixture is collected in the form of a fibrous nonwoven web, which, according to various embodiments, can be bonded or treated to provide a cohesive nonwoven material. These mixtures are referred to as "coform" materials because they are formed by combining two or more materials into a single structure in a forming step. More details about such coform materials and processes are described herein.

[0057] During the coform process, a softening agent is introduced and combined with the mixture of meltblown fiber material and secondary fiber material. In various embodiments described herein, softening agents (e.g., silicones) can be introduced into the coform material at different stages to achieve desired material properties (e.g., softness) and manufacturing efficiency. As described herein, various embodiments of nonwoven web materials have a unique combination of softness and strength properties and can be used to more efficiently manufacture consumer products (such as wet wipes).

[0058] By about Figures 2 to 9 The method and apparatus described herein, wherein a meltblown fiber material can be combined with a secondary fiber material and a softening agent to produce a coform nonwoven web structure, an exemplary schematic cross-section of which can be about Figure 1 What I see. Figure 1 The example cross section of FIG shows a coform nonwoven web structure 100. The nonwoven web 100 is formed from secondary fibrous material fibers 101, meltblown fibrous material fibers 103, and a softening agent 105. Figure 1 As depicted, the secondary fibrous material fibers 101 are shown as straight, flat-ended lines, the meltblown fibrous material fibers 103 are shown as thinner, wavy lines, and the softener 105 are shown as dots.

[0059] In the illustrated embodiment, the secondary fibrous material fibers 101, the meltblown fibrous material fibers 103, and the softening agent 105 are substantially uniformly dispersed throughout the nonwoven web 100. Thus, in the illustrated embodiment, the nonwoven web 100 has a substantially uniform structure. In various embodiments, by mechanically entangled the meltblown fibrous material fibers 103 with the secondary fibrous material fibers 101, the secondary fibrous material fibers 101 can be interconnected by and remain entrapped within the meltblown fibrous material fibers 103, with the mechanical entanglement and interconnection of the fibers 101, 103 forming a cohesive, integrated fibrous structure. In various embodiments, the cohesive, integrated fibrous structure can be formed by combining the fibers 101, 103 with the softening agent 105 without any adhesive, molecular bonds, or hydrogen bonds between the two different types of fibers.

[0060] It should be understood that Figure 1 The description in is for illustrative purposes. For example, in some embodiments, the meltblown fibrous material fibers 103 and the secondary fibrous material fibers 101 can have the same size. Additionally, the meltblown fibrous material fibers 103 within the nonwoven web 100 can be arranged to be larger than Figure 1 In addition, there may be crossovers or connections between some of the meltblown fibrous material fibers 103 and the secondary fibrous material fibers 101.

[0061] In various embodiments of nonwoven web 100, it may be particularly advantageous that nonwoven web 100 has a total basis weight between about 20gsm and about 150gsm. In a more specific embodiment, nonwoven web 100 can have a total basis weight between about 50gsm and about 125gsm, or between about 40gsm and about 90gsm, or between about 50gsm and about 80gsm. This basis weight of nonwoven web 100 also can change according to the final use of desired nonwoven web 100. For example, a suitable fiber nonwoven web structure for wiping skin can limit a basis weight of about 30 to about 80gsm and desirably about 45 to 70gsm. Basis weight (in grams per square meter, g / m²) is calculated by dividing dry weight (in grams) by area (in square meters). 2 or GSM).

[0062] In various embodiments, the relative percentages of meltblown fiber material and secondary fiber material in the nonwoven web 100 can vary over a wide range depending on the desired characteristics of the nonwoven web 100. For example, the nonwoven web 100 can have about 20 to 60 weight percent meltblown fiber material and about 40 to 80 weight percent secondary fiber material. In certain embodiments, the weight ratio of meltblown fiber material to secondary fiber material can be about 20 / 80 to about 60 / 40. In more specific embodiments, the weight ratio of meltblown fiber material to secondary fiber material can be about 25 / 75 to about 40 / 60. In some embodiments, the weight ratio of meltblown fiber material to secondary fiber material is 30 / 70.

[0063] In various embodiments, the weight ratio of the softening agent to the secondary fiber material is in the range of 5 lb / MT to 100 lb / MT. In some embodiments, the weight ratio of the softening agent to the secondary fiber material is in the range of 10 lb / MT to 80 lb / MT. In some embodiments, the weight ratio of the softening agent to the secondary fiber material is in the range of 20 lb / MT to 60 lb / MT. In some embodiments, the weight ratio of the softening agent to the secondary fiber material is in the range of 20 lb / MT to 50 lb / MT. In some embodiments, the weight ratio of the softening agent to the secondary fiber material is in the range of 20 lb / MT to 40 lb / MT. In some embodiments, the weight ratio of the softening agent to the secondary fiber material is in the range of 30 lb / MT to 40 lb / MT. In some embodiments, the weight ratio of the softening agent to the meltblown fiber material and the secondary fiber material is 40 lb / MT.

[0064] In some embodiments, the nonwoven web 100 has a TS7 value (indicating softness) of less than 7.0. In some embodiments, the nonwoven web has a TS7 value of less than 6.0. In some embodiments, the nonwoven web has a TS7 value of less than 5.0. In some embodiments, the nonwoven web has a TS7 value between about 7.0 and about 3.0. In some embodiments, the nonwoven web has a TS7 value between about 6.0 and about 3.0. In some embodiments, the nonwoven web has a TS7 value between about 6.0 and about 4.0. In some embodiments, the nonwoven web has a TS7 value between about 5.5 and about 4.0.

[0065] In some embodiments, the nonwoven web 100 has a flexibility between about 2.5 mm / N and 3.5 mm / N. In some embodiments, the nonwoven web 100 has a flexibility between about 2.7 mm / N and 3.1 mm / N. In some embodiments, the nonwoven web 100 has a flexibility between 1.0 mm / N and 5 mm / N.

[0066] In some embodiments, the nonwoven web 100 has a machine direction tensile strength (MDT) between about 400 gf and about 860 gf. In some embodiments, the nonwoven web 100 has an MDT strength between about 450 gf and about 700 gf. In some embodiments, the nonwoven web 100 has an MDT strength between about 400 gf and about 550 gf.

[0067] In some embodiments, the nonwoven web 100 has a cross-direction tensile strength (CDT) of between about 150 gf and about 500 gf. In some embodiments, the nonwoven web 100 has a CDT strength of between about 200 gf and about 400 gf. In some embodiments, the nonwoven web 100 has a CDT strength of between about 250 gf and about 350 gf.

[0068] Meltblown fiber materials

[0069] Suitable meltblown fiber materials for forming fibers 103 in the nonwoven web 100 include polyolefins (e.g., polyethylene, polypropylene, polybutylene, etc.), polyamides, olefin copolymers, and polyesters. In some embodiments, the meltblown fiber material fibers 103 in the nonwoven web 100 are polypropylene. In some embodiments, the meltblown fiber material for forming the meltblown fibers 103 is a high melt flow rate metallocene-based polypropylene homopolymer (e.g., Metocene MF650X manufactured by LyondellBassell; Achieve TMAdvanced PP6945G1). In various embodiments, the meltblown fibrous material fibers 103 may have an average diameter of about 0.5 to 40 μm.

[0070] In certain embodiments, the nonwoven web 100 may include meltblown fibers 103 comprising a first polymer component and a second polymer component (referred to herein as "bicomponent fibers," also known as multicomponent fibers) or meltblown fibers comprising a homopolymer (referred to herein as "homogeneous fibers," also known as monocomponent fibers). Although the term "bicomponent fibers" is used herein, it should not be understood as limiting such fibers to comprising only two polymer components. Rather, such bicomponent fibers, as used herein, comprise at least two polymer components but may comprise additional polymer components. Bicomponent meltblown fibers and homogeneous meltblown fibers may be combined in a layered manner along with a secondary fiber material to produce a layered coform structure.

[0071] Secondary fiber materials

[0072] The secondary fiber materials suitable for use in the nonwoven web 100 or the fibers 101 forming the nonwoven web can be selected from the group consisting of one or more polyester fibers, polyamide fibers, cellulose-derived fibers (such as rayon fibers and wood pulp fibers), multicomponent fibers (such as sheath-core multicomponent fibers), natural fibers (such as silk fibers, wool fibers, or cotton fibers), or conductive fibers, or mixtures of two or more such secondary fiber materials. Other types of secondary fiber materials, such as polyethylene fibers and polypropylene fibers, as well as mixtures of two or more other types of secondary fiber materials, can be utilized. The secondary fiber material can be a microfiber, or the secondary fiber material can be a coarse fiber having an average diameter of about 300 μm to about 1,000 μm.

[0073] In at least some embodiments, the secondary fiber material forming the fiber 101 of nonwoven web 100 can be an absorbent fiber. As an example, this absorbent fiber can be the fiber formed by various pulping processes, such as kraft pulp, sulfite pulp, thermomechanical pulp, etc. In certain embodiments, wood pulp fiber is suitable for use as the secondary fiber material, and has advantages due to low cost, high absorbency and maintaining satisfactory tactile properties. Pulp fiber can include softwood fibers having an average fiber length greater than 1 mm and specifically about 2 to 5 mm based on a length-weighted average. Such softwood fibers include, but are not limited to, following northern softwood, southern softwood, redwood, red juniper, hemlock, pine (e.g., southern pine), spruce (e.g., black spruce), combinations thereof, etc. In some embodiments, the secondary fibrous material used to form the secondary fibrous material fibers 101 is rolls of ECF bleached Southern pine softwood kraft fluff pulp (medically certified, FDA approved, and BfR compliant) treated with a debonder and antistatic agent (e.g., available from Georgia-Pacific or International Paper).

[0074] In some embodiments, hardwood fibers, such as eucalyptus, maple, birch, poplar, etc., may also be used. In some cases, eucalyptus fibers may be particularly desirable for increasing the softness of the net. Eucalyptus fibers may also enhance brightness, increase opacity and change the pore structure of the net to enhance its wicking capacity. In addition, if desired, the secondary fibers obtained by recycled materials may be used, such as fiber pulp from, for example, newsprint, recycled cardboard, and office waste paper sources. In addition, other natural fibers may also be used in the present invention, such as Manila hemp, Indian grass, milkweed silk, pineapple leaves, etc. In addition, in some cases, synthetic fibers may also be used.

[0075] Other absorbent materials can be used together with the pulp fibers, such as superabsorbents in the form of fibers, particles, gels, etc. In general, superabsorbents are water-swellable materials that can absorb at least about 20 times their weight in an aqueous solution containing 0.9% by weight of sodium chloride, and in some cases can absorb at least about 30 times their weight. Superabsorbents can be formed from natural, synthetic, and modified natural polymers and materials. Examples of synthetic superabsorbent polymers include alkaline earth metal salts and ammonium salts of poly(acrylic acid) and poly(methacrylic acid), poly(acrylamide), poly(vinyl ether), copolymers of maleic anhydride with vinyl ether and α-olefin, poly(vinyl pyrrolidone), poly(vinyl morpholinone), poly(vinyl alcohol), and mixtures and copolymers thereof. In addition, superabsorbents include natural and modified natural polymers, such as hydrolyzed acrylonitrile-grafted starch, acrylic acid-grafted starch, methylcellulose, chitosan, carboxymethylcellulose, hydroxypropyl cellulose, and natural gums, such as algin, xanthan gum, locust bean gum, etc. Mixtures of natural and wholly or partially synthetic superabsorbent polymers are also useful in the present invention.

[0076] softener

[0077] Suitable softeners for the nonwoven web 100 include, for example, silicones (e.g., silicones diluted in water). In some embodiments, the softener comprises a nonionic microemulsion of a functional silicone fluid, such as WACKER HC 3502 (34% active silicone by weight) or Shin-Etsu KF-889s available from Wacker Chemie AG. In some embodiments, the softener is transparent or translucent. In some embodiments, the ratio of silicone to water in the softener is in the range of 10 / 90 to 50 / 50. In some embodiments, the weight ratio of silicone to water in the softener is about 34 / 66.

[0078] Systems and methods for making nonwoven web structures

[0079] The coform nonwoven web 100 is typically made by a process in which at least one meltblowing die (e.g., two) is positioned adjacent a chute through which absorbent material is added while the web is being formed. Some examples of such coform technology are disclosed in U.S. Pat. Nos. 4,100,324 to Anderson et al., 5,350,624 to Georger et al., and 5,508,102 to Georger et al., as well as U.S. Patent Application Publication Nos. 2003 / 0200991 to Keck et al. and 2007 / 0049153 to Dunbar et al., all of which are incorporated herein by reference in their entirety for all purposes.

[0080] In various embodiments, a method for manufacturing a nonwoven web structure is disclosed that allows for the spraying of a functional chemical during the nonwoven web formation process. The applied functional chemical may include, but is not limited to, one or more softening agents. In various embodiments, a spray system is used to apply the functional chemical directly during the web formation process to achieve uniform distribution and mixing of the functional chemical with the meltblown fiber material fibers and the secondary fiber material fibers of the web. A process airflow can be used to substantially retain the sprayed functional chemical within the web during formation and provide a substantially uniform structure.

[0081] According to various embodiments, a method for making a nonwoven web generally includes providing a stream of meltblown fibrous material, providing a stream of a secondary fibrous material, providing a stream of a softening agent, and combining the streams of meltblown fibrous material, the streams of the secondary fibrous material, and the streams of the softening agent to form a composite stream. The composite stream is then deposited onto a forming surface so that the composite stream forms a nonwoven web having a substantially uniform structure.

[0082] As discussed herein, in certain embodiments, a stream of a secondary fibrous material and a stream of a softening agent are combined to form a mixed stream. The mixed stream (of the secondary fibrous material and the softening agent) is then combined with a stream of a meltblown fibrous material to form a composite stream. In other embodiments, a stream of a secondary fibrous material and a stream of a meltblown fibrous material are combined to form a mixed stream, and then the mixed stream (of the secondary fibrous material and the meltblown fibrous material) is combined with a stream of a softening agent to form a composite stream.

[0083] According to various other embodiments, a method for making a nonwoven web generally includes providing a mat of a secondary fibrous material treated with a softening agent and combing the mat to form a mixed stream of the secondary fibrous material and the softening agent. The method also includes providing a stream of meltblown fibrous material and combining the stream of meltblown fibrous material with the mixed stream (of the secondary fibrous material and the softening agent) to form a composite stream. The composite stream is then deposited onto a forming surface so that the composite stream forms a nonwoven web having a substantially uniform structure.

[0084] Figure 2An apparatus 200 for forming a fibrous nonwoven structure according to some embodiments is shown. The apparatus 200 includes a conventional spreading roll 236 configured for pulp fiberization. The spreading roll 236 has a plurality of teeth 238 adapted to separate a mat or wadding 240 of secondary fibrous material into individual secondary fibrous materials 232 (e.g., secondary fibrous material fibers). The mat or wadding 240 of secondary fibrous material fed to the spreading roll 236 may be a pulp fiber sheet (if a two-component mixture of thermoplastic polymer fibers and secondary pulp fibers is desired), a chopped fiber mat (if a two-component mixture of thermoplastic polymer fibers and secondary chopped fibers is desired), or both a pulp fiber sheet and a chopped fiber mat (if a three-component mixture of thermoplastic polymer fibers, secondary chopped fibers, and secondary pulp fibers is desired). In aspects where, for example, an absorbent material is desired, the secondary fibrous material 232 is an absorbent fiber. The secondary fibrous material 232 may generally be selected from the materials disclosed herein for forming fibers 101 (e.g., Figure 1 shown).

[0085] The sheet or mat 240 of secondary fibrous material is fed to the spreading roll 236 by a roller arrangement 242. After the teeth 238 of the spreading roll 236 have separated the sheet or mat 240 of secondary fibrous material into individual secondary fibrous materials 232, the individual secondary fibrous materials 232 (e.g., secondary fibrous material fibers 101) are directed through nozzles 244 to form a stream 234 of secondary fibrous material 232.

[0086] The housing 246 surrounds the spreader roller 236 and provides a passage or gap between the housing 246 and the surface of the teeth 238 of the spreader roller 236. A dilution gas, such as air, is supplied by a dilution air blower 272 through a gas conduit 250 to the passage or gap between the surface of the spreader roller 236 and the housing 246. The gas is supplied in a sufficient amount to serve as a medium for conveying the secondary fibrous material 232 through the nozzles 244, thereby forming the secondary fibrous material stream 234.

[0087] In some embodiments, a dual annular manifold serves as the dilution air blower 272, providing uniform air distribution for delivery into the gas duct 250. The dilution air provided by the dual annular manifold uniformly delivers the pulp fibers to the forming zone 230 over a forming surface 258, such as a belt or wire, as will be discussed further herein.

[0088] A separate stripping air blower 274 is used to provide a secondary stripping air flow that enters the system at the junction 252 to assist in removing the secondary fibrous material 232 from the teeth 238 of the spreader roll 236. Separate dilution air blowers 272 and stripping air blowers 274 are used to allow the operator to balance the stripping air flow, allowing for optimal fiber release from the teeth 238 and increased flow rate of the secondary fibrous material stream 234.

[0089] In various embodiments, the secondary fibrous material stream 234 is conveyed through the nozzle 244 at approximately the velocity of the individual secondary fibrous materials 232 exiting the teeth 238 of the sprinkler roll 236. In other words, the secondary fibrous material 232 generally maintains a velocity in the magnitude and direction of the point at which it exited the teeth 238 of the sprinkler roll 236 as it exits the teeth 238 of the sprinkler roll 236 and enters the nozzle 244. Such an arrangement is discussed in greater detail in U.S. Patent No. 4,100,324 to Anderson et al.

[0090] like Figure 2 As shown, the softener manifold 290 is disposed below the nozzle 244, downstream of the introduction of the stream 234 of the secondary fibrous material 232 and upstream of the introduction of the streams 226, 228 of the meltblown fibrous material 220. The softener manifold 290 includes a body (e.g., a tubular body) defining one or more openings 292. A softener is introduced into the body of the softener manifold 290 under pressure so that the softener flows through the one or more openings 292 and out of the softener manifold 290, thereby forming one or more softener streams 294. The softener can generally be selected from the softeners disclosed herein for forming the softener 105 (e.g., Figure 1 shown).

[0091] In certain embodiments, the one or more openings 292 of the softener manifold each have a diameter between about 0.01 inches and 0.05 inches. In one embodiment, the one or more openings 292 of the softener manifold each have a diameter of 0.02 inches. In various embodiments, the one or more openings 292 of the softener manifold include a plurality of openings 292. In certain embodiments, the plurality of openings 292 are aligned in rows along the length of the softener manifold 290 and are evenly spaced apart from each other. In various embodiments, the openings 292 of the softener manifold are each spaced apart from each other by 0.5 inches to 2.0 inches. In one embodiment, the openings 292 of the softener manifold are each spaced apart by one inch (e.g., such that the softener manifold 290 includes one opening 292 per inch along its length). In another embodiment, the openings 292 of the softener manifold are each spaced apart by two inches (e.g., such that the softener manifold 290 includes one opening 292 per two inches along its length). In one embodiment, the softener manifold includes twelve openings 292, each having a diameter of 0.02 inches, and each opening is spaced one inch apart from each other in a linear row.

[0092] In other embodiments, the openings 292 of the softener manifold may each include a spray nozzle secured to the manifold 290. For example, in one embodiment, the openings 292 of the softener manifold include four flat spray nozzles. Each spray nozzle has, for example, an orifice diameter of 0.02 inches (e.g., McMaster-Carr anti-drip flat spray nozzle, part number 4846T112). The four spray nozzles 292 are evenly spaced apart from one another (e.g., spaced 3 inches apart along the length of the softener manifold 290).

[0093] like Figure 2 As shown, the one or more openings 292 of the softener manifold 290 are oriented so that the one or more softener streams 294 flowing from the one or more openings 292 merge with the secondary fibrous material stream 234 exiting the nozzle 244 at a certain angle. In this manner, the merging of the one or more softener streams 294 and the secondary fibrous material stream 234 forms a mixed stream 235 of secondary fibrous material and softener.

[0094] like Figure 2 As further depicted, in the apparatus 200, the softener manifold 290 is positioned on a side of the secondary fibrous material stream 234 adjacent the second meltblowing die 218 and opposite the first meltblowing die 216 (the meltblowing dies 216, 218 are discussed in greater detail herein). In this manner, the softener stream 294 discharged from the softener manifold 290 merges with the secondary fibrous material stream 234 on a side of the secondary fibrous material stream 234 that is longitudinally downstream relative to the forming surface 258. Figure 2 As shown, the softener stream 294 discharged from the softener manifold 290 merges with the secondary fibrous material stream 234 on its downstream side, which is the side adjacent the second meltblowing die 218 and the nonwoven web 254 on the forming surface 258 .

[0095] In various embodiments, the angle of the one or more softening agent streams 294 relative to the secondary fibrous material stream 234 is selected to facilitate merging of the streams. Figure 2 In the exemplary embodiment, the one or more softening agent streams 294 are angled at about 45 degrees relative to the secondary fibrous material stream 234 .

[0096] In various embodiments, the speed and flow rate of one or more softener streams 294 together with the angle of one or more softener streams 294 relative to the secondary fiber material stream 234 are configured to fully merge the softener with the secondary fiber material 232 so that the softener is substantially evenly dispersed throughout the nonwoven web material. In certain embodiments, the flow rate of one or more softener streams 294 (passing together through the softener manifold 230) is between about 250mL / min and 1000mL / min. In certain embodiments, the flow rate of one or more softener streams 294 (passing together through the softener manifold 230) is between about 400mL / min and 600mL / min. In one embodiment, the flow rate of one or more softener streams 294 (passing together through the softener manifold 230) is 425mL / min. In another embodiment, the flow rate of one or more softener streams 294 (passing together through the softener manifold 230) is 600mL / min.

[0097] Device 200 also includes a first meltblowing die 216 and a second meltblowing die 218, and the first meltblowing die and the second meltblowing die are oriented so that they are relative to each other. Each meltblowing die 216, 218 is associated with a pellet hopper 212, 212' and an extruder 214, 214'. The pellets or fragments of thermoplastic polymers (not shown) are introduced into each pellet hopper 212, 212' to be fed into meltblowing die 216, 218. Extruder 214 has an extrusion screw (not shown), which is driven by a conventional drive motor (not shown). When polymer advances through extruder 214, because the drive motor rotates the extrusion screw, the polymer is gradually heated to a molten state. Thermoplastic polymer is heated to a molten state and can be completed in multiple discontinuous steps, and its temperature gradually increases as it advances through the discontinuous heating zone of extruder 214 towards two meltblowing dies 216 and 218 respectively. The meltblowing dies 216, 218 may be another heating zone where the temperature of the thermoplastic resin is maintained at an elevated level for extrusion.

[0098] exist Figure 2In the exemplary embodiment of the present invention, each meltblowing die head 216, 218 is configured so that the two attenuating gas streams of each die head converge to form a single gas stream that entrains and attenuates the meltblown fibrous material 220 as it exits the small holes or orifices 224 in the respective meltblowing die head 216, 218. The meltblown fibrous material 220 is attenuated into fibers or, depending on the degree of attenuation, into microfibers having a small diameter that is generally smaller than the diameter of the orifice 224. Thus, the meltblowing dies 216 and 218 each discharge a meltblown fibrous material stream 226, 228 consisting of gas containing entrained and attenuated meltblown fibrous material 220 (e.g., thermoplastic polymer fibers). The first meltblown fibrous material stream 226 and the second meltblown fibrous material stream 228 containing the meltblown fibrous material 220 are aligned to converge at the forming zone 230.

[0099] The mixed stream 235 of the secondary fibrous material 232 and the softening agent is combined with two meltblown fibrous material streams 226, 228 of meltblown fibrous material 220 (e.g., thermoplastic polymer fibers or microfibers) at the forming zone 230 to form a composite stream 256. In various embodiments, the fibers (e.g., microfibers) of the meltblown fibrous material streams 226, 228 are in a soft, nascent state at an elevated temperature as they turbulently mix with the secondary fibrous material 232 and softening agent in the air within the forming zone 230. The combining of the mixed stream 235 into the two meltblown fibrous material streams 226, 228 is designed to produce a distribution of the secondary fibrous material 232 and softening agent within the mixed meltblown fibrous material streams 226, 228 of the meltblown fibrous material 220. Figure 2 As shown, this can be accomplished by merging a mixed stream 235 (comprising a secondary fibrous material 232 and a softening agent) between two opposing streams 226, 228 of meltblown fibrous material such that all three streams converge in a controlled manner. Figure 9 The orientation of the meltblown fiber material streams 226, 228 relative to the mixed stream 235 is discussed further.

[0100] Figure 9 The orientation of the meltblown fibrous material streams 226, 228 relative to the mixed stream 235 is illustrated and highlights process variables that may affect the type and characteristics of the nonwoven web 254. Various forming distances that affect the type of fibrous nonwoven web structure 254 are also shown.

[0101] In various embodiments, the meltblown fiber material streams 226, 228 comprising meltblown fiber material 200 (e.g., thermoplastic polymer fibers) are aligned to converge at a forming zone 230 (also referred to as an impact zone). Typically, the meltblowing dies 216, 218 are arranged at an angle relative to the forming surface 258, as described in U.S. Pat. Nos. 5,508,102 and 5,350,624 to Georger et al.

[0102] The use of meltblowing dies 216, 218 as described in various embodiments herein allows for improved forming and softness characteristics. The meltblowing dies 216, 218 are mounted so that they can each be positioned at an angle θ. Figure 9 As shown, angle θ is measured from a plane "A" that is tangential to the meltblowing dies 216, 218 and generally parallel to the forming surface 258 (e.g., an endless belt or line). Typically, each die 216, 218 is positioned and mounted at an angle θ such that the streams of meltblown fiber material 226, 228 generated from the die intersect the forming zone 230. In some embodiments, angle θ may be in the range of about 30 degrees to about 75 degrees. In certain embodiments, angle θ may be in the range of about 35 degrees to about 60 degrees. In other embodiments, angle θ may be in the range of about 40 degrees to about 55 degrees.

[0103] like Figure 9 As shown, the meltblowing dies 216, 218 are separated by a distance α. Generally speaking, the distance α can range up to about 41 cm (16 inches). In some embodiments, the distance α can range from about 13 cm (5 inches) to about 25 cm (10 inches). In other embodiments, the distance α can range from about 15 cm (6 inches) to about 21 cm (8 inches). Figure 9 It can be appreciated that the distance α between the meltblowing dies 216 , 218 and the angle θ of each meltblowing die head 216 , 218 determine the location of the forming zone 230 .

[0104] The distance from the forming zone 230 to the tip of each meltblowing die 216, 218 (i.e., distance X) should generally be set to minimize dispersion of each meltblown fiber material stream 226, 228. For example, in various embodiments, the distance X can range up to about 41 cm (16 inches). In certain embodiments, the distance should be greater than 6 cm (2.5 inches). For example, for a distance X in the range of about 6 cm (2.5 inches) to 16 cm (6 inches), the distance from the tip of each meltblowing die 216, 218 to the forming zone 230 can be determined by the spacing α between the die tips and the die angle θ using the following formula:

[0105] X=α / (2cosθ)

[0106] In general, dispersion of the composite stream 256 can be minimized by selecting an appropriate vertical forming distance (i.e., distance β) before the composite stream 256 contacts the forming surface 258. β is the distance from the tip of the meltblowing die 216, 218 (e.g., at the orifice 224 of the die) to the forming surface 258. In various embodiments, a shorter vertical forming distance is generally desired to minimize dispersion. This is balanced by the need to solidify the extruded fibers from their viscous semi-molten state before contacting the forming surface 258. For example, in various embodiments, the vertical forming distance β may be in the range of about 7 cm (3 inches) to about 38 cm (15 inches) from the meltblowing die tip. Ideally, in certain embodiments, the vertical distance β may be about 10 cm (4 inches) to about 28 cm (11 inches) from the meltblowing die tip.

[0107] An important component of the vertical forming distance β is the distance (i.e., distance Y) between the forming zone 230 and the forming surface 258. In various embodiments, the forming zone 230 is positioned so that the composite stream 256 has only a minimum distance (Y) to travel to reach the forming surface 258 to minimize dispersion of entrained fibers of the secondary fibrous material and fibers of the meltblown fibrous material. For example, in various embodiments, the distance (Y) from the forming zone to the forming surface can range up to about 31 cm (12 inches). Desirably, in certain embodiments, the distance (Y) from the forming zone 230 to the forming surface 258 can range from about 5 cm (3 inches) to about 18 cm (7 inches). The distance from the forming zone 230 to the forming surface 258 can be determined from the vertical forming distance β, the spacing between the die tips (α), and the die angle (θ) using the following formula:

[0108] Y=β-((α / 2)*cosθ)

[0109] As about Figure 2 As discussed, the secondary fibrous material stream 234 is emitted from the nozzle 244 before being combined with the softening agent stream 294 to form the mixed stream 235. Generally, the nozzle 244 is positioned with its vertical axis substantially perpendicular to the forming surface 258. Thus, in various embodiments, both the secondary fibrous material stream 234 and the mixed stream 235 are oriented in a direction substantially perpendicular to the forming surface 258.

[0110] In certain embodiments, it may be desirable to cool the secondary fibrous material stream 234. For example, cooling the secondary fibrous material stream 234 can accelerate the quenching of the molten or viscous meltblown fibrous material and provide a shorter distance between the meltblowing die tip and the forming surface 258, which can be used to minimize fiber dispersion. In some embodiments, the temperature of the secondary fibrous material stream 234 can be cooled to a temperature of about 65 to about 85 degrees Fahrenheit.

[0111] By balancing the meltblown fiber material streams 226, 228 and the mixed stream 235, the desired die angle θ of the meltblowing dies 216, 218, the vertical forming distance (β), the distance between the meltblowing die tips (α), the distance between the forming zone 230 and the meltblowing die tips (X), and the distance between the forming zone 230 and the forming surface 258 (Y), controlled integration of the secondary fiber material 232 and the softening agent within the meltblown fiber material streams 226, 228 can be provided.

[0112] Return Reference Figure 2 In order to convert the composite stream 256 (comprising the meltblown fibrous material 220, the secondary fibrous material 232, and the softening agent) into a nonwoven structure 254 comprised of a cohesive mixture of the meltblown fibrous material 220, the secondary fibrous material 232, and the softening agent, a collecting apparatus is positioned in the path of the composite stream 256. The collecting apparatus includes a forming surface 258 upon which the composite stream 256 is disposed. Figure 2 In the exemplary embodiment of the present invention, the forming surface 258 is an endless belt that is conventionally driven by rollers 260 and rotates as shown by directional arrows 262. Other collecting devices are well known to those skilled in the art and can be used in place of the endless belt. For example, in other embodiments, a porous drum apparatus can be used. The composite stream 256 (of the meltblown fibrous material 220, the secondary fibrous material 232, and the softening agent) is collected on the forming surface 258 as a cohesive mixture of fibers to form the nonwoven web 254.

[0113] The deposition of fibers into composite stream 256 is aided by an offline vacuum supplied by a negative air pressure unit, or offline exhaust system 280. Unlike conventional machines, the illustrated offline exhaust system has an increased number of zones, providing three zones in the longitudinal direction. For example, a first zone 282 is located longitudinally upstream of forming zone 230, a secondary zone 284 is located directly below the pump nozzle and forming zone 230, and a third zone 286 is located longitudinally downstream of forming zone 230. In various embodiments, second zone 284 has the highest air flow, first zone 282 has the lowest air flow, and third zone 286 has a higher air flow than first zone 282 but lower than second zone 284. In other embodiments, zones 284, 282, and 286 can also be supplied with the same air flow, if found to be optimal. The zoned offline exhaust system 280 provides increased air flow where needed and better control of forming zone air management, resulting in improved forming and uniformity.

[0114] The fibrous nonwoven web structure 254 is cohesive and can be removed from the forming surface 258 as a self-supporting nonwoven material. In various embodiments, the nonwoven web 254 has sufficient strength and integrity to be used without any post-processing, such as pattern bonding, etc. In certain embodiments, a pair of hold-down rolls or pattern bonding rolls can be used to bond portions of the material.

[0115] According to the apparatus 200 and related processes described above, the thermoplastic polymer fibers are mechanically entangled with the secondary fibrous material 232, and the secondary fibrous material is interconnected by the meltblown fibrous material 220 and remains trapped within the meltblown fibrous material. The mechanical entanglement and interconnection of the polymer fibers and the secondary fibrous material alone can form a cohesive, integrated fibrous structure (e.g., a coform nonwoven web structure 254). The cohesive, integrated fibrous structure can be formed from the polymer fibers and the secondary fibrous material without any adhesive, molecular, or hydrogen bonds between the two different types of fibers. Furthermore, as a result of the processes implemented on the apparatus 200, the softening agent is substantially uniformly dispersed throughout the coform nonwoven web structure 254, thereby enhancing various properties of the nonwoven web 254 (e.g., softness).

[0116] Figure 3 Another apparatus 300 for forming a fibrous nonwoven structure 254 is shown, according to some embodiments. Figure 3 The device 300 shown is similar to Figure 2 The device 200 shown differs in the location of the softener manifold 290. Figure 3 Used and used for Figure 2 The same or similar reference numerals as those of the device 200 in FIG. 1 are used to represent the same or similar features of the device 300 .

[0117] As in Figure 2 The same as in the device 200, Figure 3 The apparatus 300 includes a softener manifold 290 having one or more openings 292 oriented so that one or more softener streams 294 exiting the one or more openings 292 merge with the secondary fibrous material stream 234 exiting the nozzle 244 at an angle. In this manner, the merging of the one or more softener streams 294 and the secondary fibrous material stream 234 forms a mixed stream 235 of the secondary fibrous material 232 and softener. However, as Figure 3 As shown, in apparatus 300, the softener manifold 290 is located on the opposite side of the secondary fiber material stream 234 (as in apparatus 200). Figure 2In other words, in apparatus 300, softener manifold 290 is positioned adjacent first meltblowing die 216 (opposite second meltblowing die 218) and adjacent an upstream portion (a portion on which no nonwoven material is deposited) of forming surface 258. In this manner, softener stream 294 discharged from softener manifold 290 merges with secondary fibrous material stream 234 on a side of the secondary fibrous material stream 234 that is longitudinally upstream of the secondary fibrous material stream 234 relative to forming surface 258.

[0118] Figure 4 Another apparatus 400 for forming a fibrous nonwoven structure 254 is shown, according to some embodiments. Figure 4 The device 400 shown is similar to Figure 2 The device 200 shown differs in the location of the softener manifold 290. Figure 4 Used and used for Figure 2 The device 200 (and Figure 3 The same or similar features of the device 400 are represented by the same or similar reference numerals as the reference numerals of the device 300 in FIG.

[0119] As in Figure 2 The same as in the device 200, Figure 4 The apparatus 400 includes a softener manifold 290 having one or more openings 292 that discharge one or more softener streams 294. However, in the apparatus 400, the softener manifold 290 is positioned below the second meltblowing die 218. In other words, in the apparatus 400, the softener manifold 290 is positioned above the forming surface 258 at a height that is less than the vertical forming distance (β) of the meltblowing die (e.g., Figure 9 shown).

[0120] like Figure 4 As shown, the secondary fibrous material stream 234 and the meltblown fibrous material streams 226, 228 are combined in the forming zone 230 to form a mixed stream 235 (composed of the secondary fibrous material 232 and the meltblown fibrous material 220). The softener manifold 290 of the apparatus 400 is oriented so that the softener stream 294 is combined with the mixed stream 235 below the forming zone 230. Thus, in the apparatus 400, the softener stream 294 is then combined with the mixed stream 235 to form a composite stream 256 (composed of the secondary fibrous material 232, the meltblown fibrous material 220, and the softener). The composite stream 256 is then deposited onto the forming surface 258 of the collecting device to form the nonwoven web 254 (e.g., in a manner similar to that described with respect to FIG. 1 ). Figure 2 (in the manner described in the device 200).

[0121] In addition, as in the apparatus 200, the softener manifold 290 in the apparatus 400 is positioned adjacent to the second meltblowing die 218 and opposite to the first meltblowing die 216. Therefore, in the apparatus 400, the softener stream 294 discharged from the softener manifold 290 is combined with the mixed stream 235 on the side of the mixed stream 235 that is longitudinally downstream relative to the forming surface 258 (i.e., the side of the mixed stream 235 that is adjacent to the second meltblowing die 218).

[0122] Figure 5 Another apparatus 500 for forming a fibrous nonwoven structure 254 is shown, according to some embodiments. Figure 5 The device 500 shown is similar to Figure 4 The device 400 shown differs in the location of the softener manifold 290. Figure 5 Used and used for Figure 4 The device 400 (and respectively for Figure 2 and Figure 3 The same or similar features of the device 500 are represented by the same or similar reference numerals as the devices 200, 300 in the drawings.

[0123] As in Figure 4 The same as in the device 400, Figure 5 The apparatus 500 includes a softener manifold 290 having one or more openings 292 oriented so that one or more softener streams 294 exiting the one or more openings 292 merge at an angle with the mixed stream 235 (comprising the secondary fibrous material 232 and the meltblown fibrous material 220). However, in the apparatus 500, the softener manifold 290 is located on the opposite side of the mixed stream 235 (from that in the apparatus 400). Figure 4 In other words, in the apparatus 500, the softener manifold 290 is positioned adjacent to the first meltblowing die 216 and opposite to the second meltblowing die 218. In this manner, the softener stream 294 discharged from the softener manifold 290 merges with the mixed stream 235 on a side of the mixed stream 235 that is longitudinally upstream relative to the forming surface 258 (i.e., a side of the mixed stream 235 that is adjacent to the first meltblowing die 216).

[0124] Figure 6 Another apparatus 600 for forming a fibrous nonwoven structure 254 is shown, according to some embodiments. Figure 6 The device 600 shown is similar to Figure 2 The device 200 shown differs in the location of the softener manifold 290. Figure 6 Used and used for Figure 2 The device 200 (and Figures 3 to 5The same or similar reference numerals as those of the devices 300-500 in FIG. 1 are used to represent the same or similar features of the device 600.

[0125] As in Figure 2 The same as in the device 200, Figure 6 The apparatus 600 includes a softener manifold 290 having one or more openings 292 that discharge one or more softener streams 294. However, in the apparatus 600, the softener manifold 290 is positioned proximate to the mat 240 of secondary fibrous material (before the mat 240 enters the spreader roll 236). The softener manifold 290 of the apparatus 600 is oriented so that the softener stream 294 merges with the mat 240 of secondary fibrous material. Once the mat 240 of secondary fibrous material has been treated with the softener, the treated mat 240 passes through the spreader roll 236. The plurality of teeth 238 of the spreader roll 236 separate the treated mat 240 of secondary fibrous material into separate treated secondary fibrous materials 232, which are themselves mixed streams 235 (comprising the secondary fibrous material and the softener). The mixed stream 235 (of the secondary fiber material and the softening agent) flows through the nozzle 244 and combines with the meltblown fibrous material 220 in the forming zone 230 to form a composite stream 256 (e.g., Figure 2 The composite stream 256 is then deposited onto a forming surface 258 of a collecting device to form a nonwoven web 254 (e.g., in a manner similar to that described for the apparatus 200 shown). Figure 2 (in the manner described in the device 200).

[0126] although Figure 6 The illustrated apparatus 600 includes a softener manifold 290 that treats the mat 240 of secondary fibrous material 232 immediately before it enters the spreader roll 236, but in other embodiments, the mat 240 of secondary fibrous material is treated with a softener at a location remote from the apparatus 600. In such embodiments, the apparatus 600 may not include a softener manifold 290, and the treated mat 240 of secondary fibrous material is fed into the spreader roll 236 (e.g., in a manner similar to that described above). Figure 6 In some embodiments, the softening agent-treated mat 240 of secondary fibrous material may be stored until it is used to convert the nonwoven web 254. In some embodiments, the softening agent may be added during the process of forming the mat 240 and thoroughly dispersed throughout the secondary fibrous material (e.g., such that a softening agent-treated mat 240 supplied from a remote location may then be used in the apparatus 600 without the need for a softener manifold 290).

[0127] In some embodiments, it is desirable to feed at least one additional mat of secondary fibrous material into the piling roll 236 along with the mat 240 of secondary fibrous material. In such embodiments, the mats of secondary fibrous material are stacked in layers and enter the piling roll simultaneously. This may be advantageous in embodiments such as those discussed above, where a softening agent is included in the mat 240 of secondary fibrous material. In some cases, using at least one additional untreated mat of secondary fibrous material (e.g., without the addition of a softening agent) between the piling roll 236 and the treated mat of secondary fibrous material can reduce the likelihood of the mat 240 adhering to the teeth 238 of the piling roll 236. In such embodiments, the treated mat of secondary fibrous material (e.g., treated with a softening agent) is placed over an untreated mat of secondary fibrous material (e.g., where the untreated mat is not treated with a softening agent). The treated mat of secondary fibrous material and the untreated mat of secondary fibrous material are then fed into the piling roll 236. Because the mat of secondary fibrous material that has been treated with the softening agent is covered on one side by the untreated mat, the treated mat of secondary fibrous material is less likely to adhere to the teeth 238 of the spreader roll. The plurality of teeth 238 of the spreader roll 236 separate the untreated mat of secondary fibrous material and the treated mat of secondary fibrous material into separate streams of secondary fibrous material 232 that are mixed with the softening agent to form a mixed stream 235. The mixed stream 235 of secondary fibrous material and softening agent flows through the nozzle 244 and merges with the meltblown fibrous material streams 226, 228 in the forming zone 230 to form a composite stream 256 (e.g., similar to Figure 2 The device 200 shown).

[0128] In certain embodiments, two additional untreated mats of minor fibrous material are included with the treated mat of minor fibrous material. In such embodiments, the treated mat of minor fibrous material (e.g., treated with a softening agent) is disposed between a first untreated mat of minor fibrous material and a second untreated mat of minor fibrous material (e.g., wherein the first untreated mat and the second untreated mat are not treated with a softening agent). The first untreated mat of minor fibrous material, the treated mat of minor fibrous material, and the second untreated mat of minor fibrous material are then fed into a spreading roller 236. Because both surfaces of the softening agent-treated mat of minor fibrous material are covered by the untreated mat, the teeth 238 of the spreading roller 236 first contact the untreated mat to reduce the likelihood that the treated mat of minor fibrous material will adhere to the teeth 238 of the spreading roller. The plurality of teeth 238 of the spreading roller 236 separate the first untreated mat of minor fibrous material, the treated mat of minor fibrous material, and the second untreated mat of minor fibrous material into separate streams of minor fibrous material 232 mixed with the softening agent to form a mixed stream 235. The mixed stream 235 of secondary fiber material and softening agent flows through the nozzle 244 and merges with the meltblown fiber material streams 226, 228 in the forming zone 230 to form a composite stream 256 (e.g., similar to Figure 2 The device 200 shown).

[0129] Figure 7 Another apparatus 700 for forming a fibrous nonwoven structure 254 is shown, according to some embodiments. Figure 7 The device 700 shown is similar to Figure 2 The device 200 shown differs in the location of the softener manifold 290. Figure 7 Used and used for Figure 2 The device 200 (and Figures 3 to 6 The same or similar features of device 400 are represented by the same or similar reference numerals as devices 300-600 in FIG.

[0130] As in Figure 2 The same as in the device 200, Figure 7 The apparatus 700 includes a softener manifold 290 having one or more openings 292 that discharge one or more softener streams 294. However, in the apparatus 700, the softener manifold 290 is positioned below the second meltblowing die 218. In other words, in the apparatus 700, the softener manifold 290 is positioned above the forming surface 258 at a height that is less than the vertical forming distance (β) of the meltblowing die (e.g., Figure 9 shown).

[0131] In addition, the softener manifold 290 of the apparatus 700 is oriented so that the softener stream 294 merges with the second meltblown fibrous material stream 228 above the forming zone 230. Thus, in the apparatus 700, the second meltblown fibrous material stream 228 and the softener stream 294 merge to form a mixed stream 235 (composed of the meltblown fibrous material stream 220 and the softener). The mixed stream 235 then merges with the secondary fibrous material stream 234 and the first meltblown fibrous material stream 226 at the forming zone 230 to form a composite stream 256 (composed of the secondary fibrous material 232, the meltblown fibrous material 220, and the softener). The composite stream 256 is then deposited onto the forming surface 258 of the collecting device to form the nonwoven web 254 (e.g., in a manner similar to that described with respect to FIG. 1 ). Figure 2 (in the manner described in the device 200).

[0132] In addition, if Figure 7 As shown, the softener manifold 290 in the apparatus 700 is positioned so that the softener stream 294 merges with the second meltblown fibrous material 228 on the downstream side of the second meltblown fibrous material stream 228, which downstream side is the side closer to the nonwoven web 254 and the forming surface 258. In other embodiments, the softener manifold 290 can be positioned and oriented so that the softener stream 294 merges with the second meltblown fibrous material stream 228 on the upstream side of the second meltblown fibrous material stream 228. In other embodiments, the softener manifold 290 can be positioned and oriented so that the softener stream 294 merges with the first meltblown fibrous material stream 226 on the downstream side of the first meltblown fibrous material stream 226. In other embodiments, the softener manifold 290 can be positioned and oriented so that the softener stream 294 merges with the first meltblown fibrous material stream 226 on the upstream side of the first meltblown fibrous material stream 226.

[0133] Figure 8 Another apparatus 800 for forming a fibrous nonwoven structure 254 is shown, according to some embodiments. Figure 8 The device 800 shown is similar to Figure 7 The device 700 shown differs in the location of the softener manifold 290. Figure 8 Used and used for Figure 8 The device 800 (and respectively for Figures 2 to 6 The same or similar features of the device 800 are represented by the same or similar reference numerals as the reference numerals of the devices 200, 600 in FIG.

[0134] As in Figure 7 As in the device 700, Figure 8The apparatus 800 includes a softener manifold 290 having one or more openings 292 oriented so that one or more softener streams 294 exiting the one or more openings 292 merge at an angle with other material streams (e.g., the secondary fiber material stream 234 and the meltblown fiber material streams 226, 228). However, in the apparatus 800, the softener manifold 290 is positioned and oriented so that the softener stream 294 merges with each of the secondary fiber material stream 234, the first meltblown fiber material stream 226, and the second meltblown fiber material stream 228 in the forming zone 230. In this manner, the various material streams 234, 226, 228, 294 all merge together in the forming zone 230 to form the composite stream 256.

[0135] like Figure 8 As shown, the softener stream 294 discharged from the softener manifold 290 is merged into the forming zone 230 on the downstream side relative to the longitudinal direction of the forming surface 258 (i.e., the side of the forming zone 230 adjacent to the second meltblowing die 218 and closer to the nonwoven material 254 on the forming surface 258).

[0136] It should be understood that the present disclosure is by no means limited to the above-described embodiments. In alternative embodiments, for example, a first meltblowing die and a second meltblowing die may be employed that extend substantially across the forming surface in a direction substantially transverse to the direction of movement of the forming surface. The die head may also be arranged substantially vertically, i.e., arranged perpendicular to the forming surface, so that the meltblown fibers produced thereby are blown directly downward onto the forming surface. This configuration is well known in the art and is described in more detail, for example, in U.S. Patent Application Publication No. 2007 / 0049153 to Dunbar et al., which is incorporated herein by reference in its entirety for all purposes. In addition, although the above-described embodiments employ multiple meltblowing dies to produce fibers of different sizes, a single die head may also be employed. An example of such a process is disclosed, for example, in U.S. Patent No. 7,168,932 to Lassig et al., which is incorporated herein by reference in its entirety for all purposes.

[0137] Example nonwoven web

[0138] Various nonwoven webs were formed according to aspects of the present disclosure and tested to determine specific web properties, including softness, strength, and flexibility.

[0139] Use About Figure 2The apparatus 200 is described to form a first set of example nonwoven webs (PSD-10 and PSD-40). Thus, each of the first example nonwoven webs (PSD-10 and PSD-40) includes a secondary fiber material, a meltblown fiber material, and a softening agent (e.g., a nonwoven web 100 formed from secondary fiber material fibers 101, meltblown fiber material fibers 103, and softening agent 105, as shown in FIG. Figure 1 ). In addition, each of the example webs (PSD-10 and PSD-40) was formed using a process in which a softening agent was combined with a stream of secondary fibrous material to form a mixed stream (of secondary fibrous material and softening agent), wherein the softening agent stream was combined with the stream of secondary fibrous material on a side of the stream of secondary fibrous material that was longitudinally downstream relative to the forming surface (e.g., as described with respect to Figure 2 ), and wherein the mixed stream is then combined with the meltblown fibrous material stream to form a composite stream that is deposited onto the forming surface. Additionally, a control nonwoven web (Control 1) was formed using the same method, but without using a softening agent.

[0140] Web Examples PSD-10, PSD-40, and Control 1 were formed with a total basis weight of 70 gsm. The secondary fiber material used was a pulp mat supplied by International Paper (rolled ECF bleached Southern pine softwood kraft fluff pulp treated with debonders and antistatic agents, medically certified, FDA approved, and BfR compliant) and comprised approximately 70% by weight (i.e., 49 gsm) of each example nonwoven web. The meltblown fiber material used was a high melt flow rate metallocene-based polypropylene homopolymer (Achieve TM Advanced PP6945G1) and comprised approximately 30% by weight (i.e., 21 gsm) of each example nonwoven web. The softener used was silicone (WACKER HC 3502) and was provided in varying amounts in each example nonwoven web (approximately 0.000-0.315 gsm, or 0-40 lbs / MT of pulp). The softener manifold used included twelve openings, each having a diameter of 0.02 inches, and each opening was spaced 1.0 inches apart from one another in linear rows. Specific characteristics of the example webs PSD-10, PSD-40, and Control 1 are shown in Table 1 below.

[0141] Table 2 reports the performance properties of the exemplary nonwoven webs PSD-10, PSD-40, and Control 1. More specifically, the exemplary nonwoven webs PSD-10, PSD-40, and Control 1 were tested for strength according to the CDT and MDT Strength Test Methods described herein, and for softness and flexibility according to the EMTEC TSA Softness and Flexibility Test Methods described herein.

[0142]

[0143] Table 1

[0144]

[0145]

[0146] Table 2

[0147] Use About Figure 3 The apparatus 300 is described to form a second set of example nonwoven webs (PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80). Thus, each of the example nonwoven webs PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, and PSU-80 includes a secondary fiber material, a meltblown fiber material, and a softening agent (e.g., a nonwoven web 100 formed from secondary fiber material fibers 101, meltblown fiber material fibers 103, and softening agent 105, as shown in FIG. 1 ). Figure 1 ). In addition, each of the example webs (PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80) was formed using a process in which a softening agent was combined with a stream of secondary fibrous material to form a mixed stream (of secondary fibrous material and softening agent), wherein the softening agent stream was combined with the stream of secondary fibrous material on a side of the stream of secondary fibrous material that was longitudinally upstream relative to the forming surface (e.g., as described with respect to Figure 3 300 in the apparatus ), and wherein the mixed stream is then combined with the meltblown fibrous material stream to form a composite stream that is deposited onto the forming surface. Additionally, a control nonwoven web (Control 2) was formed in which no softening agent was used.

[0148] Examples PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80, and Control 2 were formed with a total basis weight of 70 gsm. The secondary fiber material used was a pulp mat supplied by Georgia-Pacific (rolled ECF bleached southern pine softwood kraft fluff pulp treated with debonders and antistatic agents, medically certified, FDA approved, and BfR compliant) and accounted for approximately 70% by weight (i.e., 49 gsm) of each example nonwoven web. The meltblown fiber material used was a high melt flow rate metallocene-based polypropylene homopolymer (Metocene MF650X manufactured by LyondellBassell) and accounted for approximately 30% by weight (i.e., 21 gsm) of each example nonwoven web. The softener used was silicone (WACKER HC 3502) and was provided in varying amounts in each example nonwoven web (approximately 0.000-0.605 gsm, or 0-80 lbs / MT of pulp). The softener manifold used included twelve openings, each having a diameter of 0.02 inches, and each opening was spaced 1.0 inches apart from each other in a linear row. Specific characteristics of the example webs PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80, and Control 2 are shown in Table 3 below.

[0149] Table 4 reports the performance properties of the exemplary nonwoven webs PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80, and Control 2. More specifically, the exemplary nonwoven webs PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80, and Control 2 were tested for strength according to the CDT and MDT strength test methods described herein, and for softness and flexibility according to the EMTEC TSA softness and flexibility test method described herein.

[0150]

[0151] Table 3

[0152]

[0153] Table 4

[0154] Use About Figure 7 The apparatus 700 is described to form a third set of example nonwoven webs (MSD-10, MSD-20, MSD-40). Thus, each of the example nonwoven webs MSD-10, MSD-20, and MSD-40 includes a secondary fiber material, a meltblown fiber material, and a softening agent (e.g., a nonwoven web 100 formed from secondary fiber material fibers 101, meltblown fiber material fibers 103, and softening agent 105, as shown in FIG. Figure 1 ). In addition, each of the example webs (MSD-10, MSD-20, MSD-40) was formed using a process in which a softening agent was combined with a first stream of meltblown fibrous material to form a mixed stream (of meltblown fibrous material and softening agent), wherein the softening agent stream was combined with the meltblown fibrous material stream on a side of the meltblown fibrous material stream that was longitudinally downstream relative to the forming surface (e.g., as described with respect to Figure 7 700 in FIG), and wherein the mixed stream is then combined with the secondary fibrous material stream (and the second meltblown fibrous material stream) to form a composite stream that is deposited onto the forming surface. Additionally, the control 2 web discussed above, which did not use a softening agent, was again used as the control web.

[0155] Examples MSD-10, MSD-20, MSD-40, and Control 2 were formed with a total basis weight of 70 gsm. The secondary fiber material used was a pulp mat supplied by Georgia-Pacific (a roll of ECF bleached southern pine softwood kraft fluff pulp treated with a debonder and antistatic agent, medically certified, FDA approved, and BfR compliant) and comprised approximately 70% by weight (i.e., 49 gsm) of each example nonwoven web. The meltblown fiber material used was a high melt flow rate metallocene-based polypropylene homopolymer (Metocene MF650X manufactured by LyondellBassell) and comprised approximately 30% by weight (i.e., 21 gsm) of each example nonwoven web. The softener used was silicone (WACKER HC 3502) and was provided in varying amounts in each example nonwoven web (approximately 0.000-0.302 gsm, or 0-40 lbs / MT pulp). The softener manifold used included twelve openings, each having a diameter of 0.02 inches, and each opening was spaced 1.0 inches apart from each other in a linear row. Specific characteristics of the example meshes MSD-10, MSD-20, MSD-40, and Control 2 are shown in Table 5 below.

[0156] Table 6 reports the performance properties of the exemplary nonwoven webs MSD-10, MSD-20, MSD-40, and Control 2. More specifically, the exemplary nonwoven webs MSD-10, MSD-20, MSD-40, and Control 2 were tested for strength according to the CDT and MDT Strength Test Methods described herein, and for softness and flexibility according to the EMTEC TSA Softness and Flexibility Test Methods described herein.

[0157]

[0158]

[0159] Table 5

[0160]

[0161] Table 6

[0162] Use About Figure 8 The apparatus 800 described above forms a fourth set of example nonwoven webs (FZD-10, FZD-40). Thus, each of the example nonwoven webs FZD-10 and FZD-40 includes a secondary fiber material, a meltblown fiber material, and a softening agent (e.g., a nonwoven web 100 formed from secondary fiber material fibers 101, meltblown fiber material fibers 103, and softening agent 105, as shown in FIG. Figure 1 ). In addition, each of the example webs (FZD-10, FZD-40) was formed using a process in which a softening agent was combined with a stream of secondary fibrous material and two streams of meltblown fibrous material in a forming zone to form a composite stream (of secondary fibrous material, meltblown fibrous material, and softening agent), wherein the softening agent stream was combined with the material streams on a side of the forming zone that was longitudinally downstream relative to the forming surface (e.g., as described with respect to Figure 8 ), and wherein the composite stream is deposited onto a forming surface. Additionally, the control 2 web discussed above, in which no softener was used, was again used as a control web.

[0163] Examples FZD-10, FZD-40, and Control 2 were formed with a total basis weight of 70 gsm. The secondary fiber material used was a pulp mat supplied by Georgia-Pacific (a roll of ECF bleached southern pine softwood kraft fluff pulp treated with a debonder and antistatic agent, medically certified, FDA approved, and BfR compliant) and accounted for approximately 70% by weight (i.e., 49 gsm) of each example nonwoven web. The meltblown fiber material used was a high melt flow rate metallocene-based polypropylene homopolymer (Metocene MF650X manufactured by LyondellBassell) and accounted for approximately 30% by weight (i.e., 21 gsm) of each example nonwoven web. The softener used was silicone (WACKER HC 3502) and was provided in varying amounts in each example nonwoven web (approximately 0.000-0.302 gsm, or 0-40 lbs / MT pulp). The softener manifold used included four spray nozzles, each being a McMaster-Carr anti-drip flat spray nozzle (Part No. 4846T112) having a diameter of 0.02 inches and spaced 4.0 inches apart from each other in a linear row. Specific characteristics of the example webs FZD-10, FZD-40, and Control 2 are shown in Table 7 below.

[0164] Table 8 reports the performance properties of exemplary nonwoven webs FZD-10, FZD-40, and Control 2. More specifically, exemplary nonwoven webs FZD-10, FZD-40, and Control 2 were tested for strength according to the CDT and MDT Strength Test Methods described herein, and for softness and flexibility according to the EMTEC TSA Softness and Flexibility Test Methods described herein.

[0165]

[0166] Table 7

[0167]

[0168] Table 8

[0169] Use something like About Figure 6 The apparatus 600 described above formed a fifth set of example webs (EXP-40, EXP-60, EXP-80) but without the softener manifold. Instead, a pulp supply pretreated with softener was used as the secondary fiber material and supplied to a spreader roll for conversion into nonwoven web samples (with Figure 6 Thus, each of the example nonwoven webs EXP-40, EXP-60, and EXP-80 includes a secondary fibrous material, a meltblown fibrous material, and a softening agent (e.g., a nonwoven web 100 formed from secondary fibrous material fibers 101, meltblown fibrous material fibers 103, and softening agent 105, as shown). Figure 1 Additionally, a control nonwoven web (Control 3) was formed in which no softener was used.

[0170] Examples EXP-40, EXP-60, EXP-80, and Control 3 were formed with a total basis weight of 70 gsm. The secondary fiber material used was a pulp mat supplied by International Paper (rolled ECF bleached Southern pine softwood kraft fluff pulp treated with debonders and antistatic agents, medically certified, FDA approved, and BfR compliant) and comprised approximately 73% by weight (i.e., 51 gsm) of each example nonwoven web. The meltblown fiber material used was a high melt flow rate metallocene-based polypropylene homopolymer (Achieve TM Advanced PP6945G1) and comprised approximately 27% by weight (i.e., 19 gsm) of each example nonwoven web. The softener used was silicone (WACKER HC 3502) and was used to pretreat the pulp mat in varying amounts (approximately 0.000-0.630 gsm, or 0-80 lbs / MT of pulp). Specific characteristics of the example webs EXP-40, EXP-60, EXP-80, and Control 3 are shown in Table 9 below.

[0171] Table 10 reports the performance properties of the exemplary nonwoven webs EXP-40, EXP-60, EXP-80, and Control 3. More specifically, the exemplary nonwoven webs EXP-40, EXP-60, EXP-80, and Control 3 were tested for strength according to the MDT Strength Test Method described herein, and for softness and flexibility according to the EMTEC TSA Softness and Flexibility Test Method described herein.

[0172]

[0173] Table 9

[0174]

[0175] Table 10

[0176] As can be seen in Tables 1 to 10, the example nonwoven webs (i.e., PSD-10, PSD-40, PSU-2.5, PSU-5, PSU-10, PSU-20, PSU-40, PSU-80, MSD-10, MSD-20, MSD-40, FZD-10, FZD-40, EXP-40, EXP-60, EXP-80) produced according to the methods and apparatus described herein generally had improved softness values (TS7) compared to control webs (i.e., Control 1, Control 2, Control 3) in which no silicone was used. In addition, the example nonwoven webs in Tables 1 to 10 demonstrate that the softness (TS7) of the nonwoven web generally improves as more silicone is added to the nonwoven mixture. Tables 1 to 10 also show that the example nonwoven webs exhibit improved flexibility (mm / N) and maintain sufficient strength (gf).

[0177] Additionally, the example nonwoven webs surprisingly exhibit a sufficient combination of softness, flexibility, and strength while using relatively small amounts of silicone. In many instances, softness values of less than 6.0 (TS7) were achieved using 0.079 gsm (10 lb / MT pulp) of silicone while maintaining sufficient strength and flexibility. In further instances, softness values of less than 5.0 (TS7) were achieved using 0.302 gsm (40 lb / MT pulp) (or less) of silicone while maintaining sufficient strength and flexibility.

[0178] For processes in which a softening agent stream is combined with a secondary fibrous material stream (to form a mixed stream of softening agent and secondary fibrous material), Applicants have surprisingly discovered that combining the softening agent with the secondary fibrous material stream on a side of the secondary fibrous material stream that is longitudinally downstream relative to the forming surface (e.g., as described with respect to Figure 2The improved softness values obtained by applying the softening agent to the downstream side of the secondary fibrous material stream are reflected in the data of Tables 1 and 2 (by comparison with the softness values obtained by applying the softening agent to the upstream side of the secondary fibrous material stream as shown in Tables 3 and 4).

[0179] Absorbent articles, such as wet wipes

[0180] In various embodiments, the nonwoven web structures disclosed herein (e.g., Figure 1 Nonwoven web 100 and Figures 2 to 8 The nonwoven web 254 of the present invention can be used as a substrate in a wet wipe product, particularly a wet wipe product suitable for babies. In such embodiments, a liquid formulation is applied and absorbed into the substrate. The liquid formulation may include various components (e.g., chemicals diluted (e.g., in water) such as preservatives and fragrances) that provide desired wiping properties. In various embodiments, the liquid formulation may include water, emollients, surfactants, fragrances, preservatives, chelating agents, pH buffers, or combinations thereof, as known to those skilled in the art. The liquid may also contain lotions, medicines, and / or other active agents.

[0181] The amount of liquid contained in each wet wipe can vary depending on the type of material used to provide the wet wipe, the type of liquid used, the type of container for storing the wet wipe, and the desired end use of the wet wipe. Generally speaking, based on the dry weight of the wipe, each wet wipe can contain about 150 to about 600 weight % and desirably about 250 to about 450 weight % of liquid to improve wiping. In a specific aspect, the amount of liquid contained in the wet wipe is about 250 to about 300 weight % based on the dry weight of the wet wipe. If the amount of liquid is less than the above range, the wet wipe may be too dry and may not function fully. If the amount of liquid is greater than the above range, the wet wipe may become oversaturated and damp, and the liquid may accumulate at the bottom of the container.

[0182] Each wet wipe can be roughly rectangular in shape and can have any suitable unfolded width and length. For example, the wet wipe can have an unfolded length of about 2.0 cm to about 80.0 cm, and ideally about 10.0 cm to about 25.0 cm, and an unfolded width of about 2.0 cm to about 80.0 cm, and ideally about 10.0 cm to about 25.0 cm. Typically, each individual wet wipe is arranged in a folded configuration and stacked one on top of the other, or is a continuous strip of material with perforations to provide a stack of wet wipes. The stack of wet wipes can be placed inside a container, such as a plastic bucket, and arranged in piles for distribution to provide a package of wet wipes for ultimate sale to consumers.

[0183] As disclosed herein, applying functional chemicals (e.g., softeners) during the nonwoven web (substrate) formation process has several advantages, including improved substrate softness, improved substrate retention, and other improved substrate properties. Using the methods described herein, applicants surprisingly discovered that by applying a softener during the formation of the nonwoven web (substrate), suitable softness (TS7) can be achieved without including a softener in the liquid formulation added to the substrate to form the wet wipe. In other words, in various embodiments, the nonwoven web itself (substrate) has softness properties such that the liquid formulation applied to the substrate does not contain a softener.

[0184] Furthermore, the applicants have surprisingly discovered that the methods described herein can achieve suitable softness values using significantly less softening agent (compared to wet wipes in which the softening agent is not applied during substrate formation but rather included in the liquid formulation). For example, the applicants have surprisingly discovered that applying a softening agent during substrate formation (as shown and described herein with respect to apparatus 200-800) can produce a nonwoven web having suitable softness properties (and sufficient strength and flexibility) using approximately 55% less softening agent (e.g., for a comparable web basis weight, a nonwoven web prepared according to the methods herein using approximately 0.302 to 0.315 gsm of silicone will have substantially the same softness properties as a conventional wet wipe having approximately 0.567 gsm of silicone applied via a liquid formulation). Thus, as described herein, various embodiments can enable more efficient manufacturing of nonwoven web materials and wet wipe products made from the nonwoven web materials.

[0185] In certain embodiments, when a softener is added to a substrate during the forming process and then used to form a wet wipe product, a wider range of liquid formulations can be added to the substrate. For example, in certain embodiments, the improved softness of the substrate allows the liquid formulation to be free of softeners, which facilitates the use of a wider range of functional chemicals (e.g., chemicals that would otherwise compromise the stability of the liquid formulation if included with the softener) while maintaining the stability of the liquid formulation. Thus, various embodiments of the apparatus, systems, and methods disclosed herein provide more flexible options for producing wet wipes and other nonwoven web materials with a variety of liquid formulation chemistries, resulting in improved consumer-desired properties (e.g., softness, gentleness, and strength) in wet wipe products.

[0186] The nonwoven webs of the present disclosure can be used alternatively in a variety of articles. For example, the web can be incorporated into an "absorbent article" that can absorb water or other fluids. Examples of some absorbent articles include, but are not limited to, personal care absorbent articles such as diapers, training pants, absorbent underpants, incontinence products, feminine hygiene products (e.g., sanitary napkins), swimsuits, and the like; medical absorbent articles such as clothing, fenestration materials, padding, mattresses, bandages, absorbent drapes, and medical wipes; clothing articles; pockets, and the like. The materials and methods for forming such articles are well known to those skilled in the art. Several examples of such absorbent articles are described in U.S. Patent No. 5,649,916 to DiPalma et al., U.S. Patent No. 6,110,158 to Kielpikowski, and U.S. Patent No. 6,663,611 to Blaney et al., which are incorporated herein by reference in their entirety for all purposes. Other suitable articles are described in U.S. Patent Application Publication No. 2004 / 0060112A1 to Fell et al., U.S. Patent No. 4,886,512 to Damico et al., U.S. Patent No. 5,558,659 to Sherrod et al., U.S. Patent No. 6,888,044 to Fell et al., and U.S. Patent No. 6,511,465 to Freiburger et al., all of which are incorporated herein by reference in their entirety for all purposes. When used in absorbent articles, the nonwoven web of the present disclosure can form a component of an absorbent core or any other absorbent component of absorbent articles well known in the art.

[0187] Although various implementations have been described in detail herein, it should be understood that those skilled in the art, upon gaining an understanding of the foregoing, may readily conceive of modifications, variations, and equivalents to these embodiments. Furthermore, it should be noted that any given range presented herein is intended to include any and all lesser encompassed ranges. For example, a range of 45-90 also includes 50-90; 45-80; 46-89, etc.

[0188] EMTEC TSA Softness and Flexibility Test Method

[0189] The softness and flexibility (stiffness) of the nonwoven webs were measured using an EMTEC Tissue Softness Analyzer ("TSA") (Emtec Electronic GmbH, Leipzig, Germany). Softness was measured in terms of the TS7 value, while flexibility was measured in terms of mm / N.

[0190] The TSA consists of a rotor with vertical blades that rotate on the test piece, applying a defined contact pressure. The contact between the blades and the test piece generates vibrations, which are detected by a vibration sensor. The sensor then transmits the signal to a personal computer (PC) for processing and display. The signal is displayed as a frequency spectrum. To measure the TS7 value, the blades are pressed against the sample with a load of 100 mN and rotate at a speed of 2 revolutions per second.

[0191] To measure the TS7 value, frequency analysis is performed over a range of approximately 1 kHz to 10 kHz, and the peak amplitude occurring at 7 kHz is recorded as the TS7 value. The TS7 value represents the softness of the sample, with lower amplitudes associated with softer samples. The unit of the TS7 value is dB V2 root mean square (rms).

[0192] Test specimens were prepared by cutting circular specimens with a diameter of 112.8 mm. All samples were allowed to equilibrate under TAPPI standard temperature and humidity conditions for at least 24 hours before completing the TSA test. To measure non-wire side (NWS) softness, the sample was placed in the TSA with the air side of the sample facing up (the side of the sample collected on the forming wire facing down). To measure wire side (WS) softness, the sample was placed in the TSA with the air side of the sample facing down (the side of the sample collected on the forming wire facing up). The sample was secured and the measurement was started via the PC. The PC recorded, processed and stored all data according to the standard TSA protocol. The reported values are the average of 5 repeated tests, using a new sample for each test. Sample

[0193] As used herein, the term flexibility (or stiffness parameter (D)) refers to the output of the TSA in mm / N. Generally speaking, the flexibility value (reported in mm / N) is a measure of the deformation of a sample under a specified load. Flexibility data is collected when a bladed rotor is pressed against a test piece in two cycles at two different forces. Force 1 (100 mN) and then Force 2 (600 nM) are applied to the test piece as a pre-extension to measure the displacement D.

[0194] TSA Softness and Flexibility Test Method: TSA is calibrated according to EMTEC's instructions using a 1-point calibration method and an appropriate reference standard (e.g., "Reference 2 Sample" or equivalent, available commercially from EMTEC).

[0195] CDT and MDT strength test methods

[0196] The CDT strength test method measures the peak load value, which is the maximum force generated by the sample when it is pulled to rupture in the cross direction (CD). The samples are cut into 25 mm wide and 152 mm long using a die cutter or using a sample cutter such as a JDC Precision Sample Cutter (Thwing-Albert Instrument Company, Philadelphia, Pa., Model JDC 3-10, Serial No. 37333) and conditioned at 23±2°C and 50±5% relative humidity for at least 4 hours before testing and tested under the same environmental conditions. The length dimension of the sample should extend in the cross direction (CD) of the web from which the sample was cut. The CDT strength value is the peak load in grams-force when the sample is pulled to rupture (cross direction tensile strength). More specifically, the CDT strength value is the peak load when the sample is stretched with a force oriented in a direction that is cross-directional with the longitudinal orientation of the sample.

[0197] The MDT strength test method measures the peak load value, i.e. the maximum force generated by the sample when the sample is pulled to fracture in the machine direction (MD). The sample is cut into 25 mm wide and 152 mm long using a die cutter or using a sample cutter such as a JDC precision sample cutter (Thwing-Albert Instrument Company, Philadelphia, Pa., model JDC 3-10, serial number 37333) and treated at least 4 hours at 23 ± 2 ° C and 50 ± 5% relative humidity before testing, and tested under the same environmental conditions. The length dimension of the sample should extend in the machine direction (MD) of the web from which the sample is cut. The MDT strength value is the peak load (machine direction tensile strength) in grams-force when the sample is pulled to fracture. More specifically, the MDT strength value is the peak load when the sample is stretched by the force oriented in the machine direction of the sample.

[0198] The tensile strength tester used for CDT and MDT strength test methods is MTS Standard 41 or 43 and MTS TestSuite Elite TM (MTS Systems Corp., Research Triangle Park, NC). The load cell was selected so that the peak load value fell between 10% and 90% of the load cell's full-scale load—a 50 Newton or 100 Newton maximum load cell would typically be appropriate, depending on the strength of the test specimen. The gauge length was 76 mm, and the jaw width was 76 mm, with an approximate height of 12.7 mm. The crosshead speed was 305 mm / min, and the break sensitivity was set at 70%.

[0199] The sample is placed in the jaws of the instrument and centered vertically and horizontally with the longer dimension parallel to the direction of load application. The clamps are operated using pneumatic action and are coated with rubber. The test is then started and ends when the sample breaks. The peak load is determined and reported as the CDT (or MDT) strength value of the sample, accurate to 0.1 gf. Five (5) representative samples are tested and the arithmetic mean of all the individual samples tested is the tensile strength of the product.

[0200] Example Implementations

[0201] A number of example embodiments are provided herein. However, it should be understood that various modifications may be made without departing from the spirit and scope disclosed herein. As used in the specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a / an" and "the" include plural referents. As used herein, the term "include" and its variants are used synonymously with the term "comprise" and its variants, and are open, non-restrictive terms. Although the terms "include" and "comprising" are used herein to describe various embodiments, the terms "consisting essentially of" and "consisting of" may be used in place of "include" and "comprising" to provide more specific embodiments and are also disclosed.

[0202] Disclosed are materials, systems, devices, methods, compositions, and components that can be used in, used in conjunction with, or used to prepare the disclosed methods, systems, and devices, or are products of the disclosed methods, systems, and devices. These and other components are disclosed herein, and it should be understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed, while specific reference to each individual and collective combination and arrangement of these components may not be explicitly disclosed, each component is specifically contemplated and described herein. For example, if a device is disclosed and discussed, each and every combination and arrangement of the device is disclosed herein, and unless specifically indicated to the contrary, possible modifications are specifically contemplated. Similarly, any subset or combination of these is also specifically contemplated and disclosed. This concept applies to all aspects of the present disclosure, including but not limited to steps in methods using the disclosed systems or devices. Therefore, if there are multiple additional steps that can be performed, it should be understood that each of these additional steps can be performed using any specific method step or combination of method steps of the disclosed method, and each such combination or subset of combinations is specifically contemplated and should be considered disclosed.

Claims

1. A method of making a nonwoven web having a substantially uniform structure, the method comprising: providing at least one stream of secondary fibrous material; providing at least one stream of meltblown fibrous material; providing at least one stream of a softening agent; combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form a composite stream comprising the secondary fibrous material, the meltblown fibrous material, and the softening agent; as well as The composite stream is deposited onto a forming surface to form a nonwoven web.

2. The method of claim 1 , wherein combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: combining the at least one stream of secondary fibrous material and the at least one stream of softening agent to form a combined stream of secondary fibrous material and softening agent; as well as The mixed stream is then combined with the at least one stream of meltblown fibrous material to form the composite stream.

3. The method of claim 1 , wherein combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: combining the at least one stream of meltblown fibrous material and the at least one stream of softening agent to form a combined stream of meltblown fibrous material and softening agent; as well as The mixed stream is then combined with the stream of the secondary fibrous material to form the composite stream.

4. The method of claim 3, wherein the at least one stream of meltblown fibrous material comprises a first stream of meltblown fibrous material and a second stream of meltblown fibrous material; wherein combining the at least one stream of meltblown fibrous material and the at least one stream of softening agent to form the mixed stream comprises combining the first stream of meltblown fibrous material and the at least one stream of softening agent to form the mixed stream; and Also included is combining the second stream of meltblown fibrous material with the mixed stream and the stream of secondary fibrous material to form the composite stream.

5. The method of claim 1 , wherein combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: The at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent are combined in a forming zone to form the composite stream.

6. The method of claim 1 , wherein combining the at least one stream of secondary fibrous material, the at least one stream of meltblown fibrous material, and the at least one stream of softening agent to form the composite stream comprises: combining the at least one stream of secondary fibrous material and the at least one stream of meltblown fibrous material to form a combined stream of secondary fibrous material and meltblown fibrous material; as well as The mixed stream is then combined with the at least one stream of softening agent to form the composite stream.

7. The method of claim 1, wherein the meltblown fibrous material comprises a polymer.

8. The method of claim 4, wherein the polymer comprises polypropylene or polyethylene.

9. The method of claim 1, wherein the secondary fibrous material comprises wood pulp.

10. The method of claim 1, wherein the softening agent comprises silicone.

11. The method of claim 1 , wherein the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is in the range of 20 / 80 to 60 / 40.

12. The method of claim 11, wherein the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is in the range of 25 / 75 to 40 / 60.

13. The method of claim 12, wherein the weight ratio of the meltblown fiber material to the secondary fiber material in the nonwoven web is 30 / 70.

14. The method of claim 1 wherein the weight ratio of the softening agent to the secondary fiber material in the nonwoven web is in the range of 20 lb / MT to 80 lb / MT.

15. The method of claim 14, wherein the weight ratio of the softening agent to the secondary fiber material in the nonwoven web is 40 lb / MT.

16. The method of claim 1, wherein the nonwoven web has a TS7 value of less than 7.

0.

17. The method of claim 16, wherein the nonwoven web has a TS7 value of less than 6.

0.

18. The method of claim 17, wherein the nonwoven web has a TS7 value of less than 5.

0.

19. A method of making a nonwoven web having a substantially uniform structure, the method comprising: providing a mat of secondary fibrous material treated with a softening agent; combing the mat of secondary fibrous material to form at least one mixed stream comprising the secondary fibrous material and the softening agent; providing at least one stream of meltblown fibrous material; combining the at least one stream of meltblown fibrous material with the at least one mixing stream to form a composite stream comprising the secondary fibrous material, the meltblown fibrous material, and the softening agent; as well as The composite stream is deposited onto a forming surface to form a nonwoven web.

20. The method of claim 19, wherein providing a mat of secondary fibrous material treated with a softening agent comprises: providing said mat of secondary fibrous material; as well as The stream of softening agent is combined with the mat of secondary fibrous material.

21. The method of claim 19, wherein providing a mat of secondary fibrous material treated with a softening agent comprises: providing the secondary fiber material; combining a stream of softening agent with the secondary fibrous material; as well as The combined secondary fibrous material and softening agent are formed into the mat of secondary fibrous material treated with softening agent.

22. The method of claim 19, wherein the mat of secondary fibrous material comprises a first mat of secondary fibrous material, and further comprising: providing a second mat of secondary fiber material; as well as The second mat of secondary fibrous material is combed with the first mat of secondary fibrous material to form a mixed stream of the secondary fibrous material and the softening agent.

23. The method of claim 22, further comprising providing a third mat of secondary fibrous material, wherein the first mat of secondary fibrous material is disposed between the second mat of secondary fibrous material and the third mat of secondary fibrous material; and The first mat of secondary fibrous material, the second mat of secondary fibrous material, and the third mat of secondary fibrous material are combed to form a mixed stream of the secondary fibrous material and the softening agent.

24. The method of claim 19, wherein the meltblown fibrous material comprises a polymer.

25. The method of claim 24, wherein the polymer comprises polypropylene or polyethylene.

26. The method of claim 19, wherein the fibrous material comprises wood pulp.

27. The method of claim 19, wherein the softening agent comprises silicone.

28. The method of claim 19, wherein the weight ratio of the meltblown fibrous material to the secondary fibrous material in the nonwoven web is in the range of 20 / 80 to 60 / 40.

29. The method of claim 28, wherein the weight ratio of the meltblown fibrous material to the secondary fibrous material in the nonwoven web is in the range of 25 / 75 to 40 / 60.

30. The method of claim 29, wherein the weight ratio of the meltblown fibrous material to the secondary fibrous material in the nonwoven web is 30 / 70.

31. The method of claim 19, wherein the weight ratio of the softening agent to the secondary fiber material in the nonwoven web is in the range of 20 lb / MT to 80 lb / MT.

32. The method of claim 31 wherein the weight ratio of the softening agent to the secondary fibrous material in the nonwoven web is 40 lb / MT.

33. The method of claim 19, wherein the nonwoven web has a TS7 value of less than 7.

0.

34. The method of claim 33, wherein the nonwoven web has a TS7 value of less than 6.

0.

35. The method of claim 34, wherein the nonwoven web has a TS7 value of less than 5.0.

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