CN104302257B - Apparatus and process for aperturing and stretching a web - Google Patents

Abstract

Apparatuses and processes for aperturing and stretching a web are disclosed. In one embodiment, the method involves feeding a web into a nip that is formed between at least one pair of intermeshing rolls. The first roll is a raised ridge rotary knife aperturing roll and the second roll is a ring roll; both rolls comprise ridges and grooves. The first roll comprises a plurality of spaced-apart teeth extending outwardly from the top surface of the ridges, said teeth having tips, wherein the top surface of said ridges are disposed between the tips of said teeth and the bottom surface of said grooves. These apparatuses and processes enable a web to be formed which comprises apertures having greater open area than previously achievable with traditional processes and apparatuses.

Description

Apparatus and method for aperturing and stretching a fiber web

technical field

The present invention relates to apertured web materials and apparatus and methods for apertured and stretched webs to form such materials.

Background technique

Various methods and apparatus for aperturing, deforming and/or stretching webs are disclosed in the patent literature. In the case of utilizing an aperture method such as roller knife aperture, it is difficult to produce a web with closely spaced apertures having a desired width in the cross direction ("CD"). In order to space the rows of holes closer together, the activation teeth can be provided with very small included angles. However, this method poses problems, since the holes produced do not have sufficient hole width in the transverse direction, even at high engagement depths (interference of the activating toothed roller with the counter-ring roller). The resulting pores are often elongated in the machine direction, resulting in a slit-like appearance, low open area, and potential stress concentrations that can lead to tearing in use. The creation of slit-like, low open area pores is especially problematic when using tougher and more tear-resistant webs. Rounded or tapered thermal needle apertures are a common approach, but have the disadvantage of requiring greater alignment accuracy of the mating rollers, and they generally result in greater aperture spacing. Rounded or tapered thermal needle apertures are generally performed at lower line speeds.

It is possible to cylindrically ring roll an apertured web to stretch it, but may result in alternating rows of aperture sizes because the apertures cannot be registered with the subsequent ring-roll stretching process. Due to the variable spreading of the substrate, it is difficult to align the structure laterally with subsequent processes. Cylindrical ring rolling may also significantly weaken the web, making it more susceptible to tearing.

It would be desirable to produce a web having discrete, closely spaced pores of greater transverse width than previously possible. There is a need for an apertured web that is stronger in the cross direction and thus less prone to tearing in the cross direction. What is needed is a method of producing apertured webs with larger, wider, more open pores. There is also a need for an apparatus that allows a web to be apertured with apertures of a desired larger width in the transverse direction.

There are many known processes for producing webs with ridges and grooves, such as ring rolling. There are also many known processes for producing webs with apertures, such as hot needle aperturing. However, it is difficult to produce a corrugated web with alternating ridges and grooves aligned with a specific hole pattern. There are processes for micro-drilling followed by ring rolling. However, this results in a flat web without corrugations. The web (flat strip) with ridges and grooves can be formed via spraying air or water on the patterned belt. However, air or water spraying is a much slower process and requires more energy than the invention described herein. In addition, the ridges are not hollow and are able to hold more fluid.

It is desirable to create a web having alternating ridges and grooves, with holes located at specific locations in the web, eg, in the grooves or in the ridges. There is a need for an apertured web comprising an aligned corrugation pattern.

These are goals of the present invention; embodiments described herein can achieve various combinations of these goals. A particular embodiment may, but is not required to, implement each objective.

Contents of the invention

The present invention relates to apertured and often corrugated web materials, and apparatus and methods for apertured webs to produce such materials. Such materials may be provided as components of products such as absorbent articles (such as topsheets, backsheets, acquisition layers, liquid management layers, and absorbent cores), packaging (such as flow wraps, shrink wraps, and polybags), wipes, Facial tissue, toilet paper, paper towels, etc. There are numerous non-limiting embodiments of the invention.

The present invention relates to an apparatus comprising two intermeshing forming structures forming a nip therebetween, said apparatus comprising: a first forming structure comprising: a plurality of first ridges on a surface of the forming structure and a first groove, wherein the first ridge has a top surface and the first groove has a bottom surface; and a plurality of spaced apart teeth extending outwardly from the top surface of the first ridge , each tooth is capable of forming a hole, wherein the top surface of the first ridge is located between the tip of the tooth and the bottom surface of the first groove; and a second forming structure comprising a plurality of consecutive first grooves; Two ridges and a second groove.

The present invention also relates to an apparatus comprising two intermeshing counter-rotating rollers forming a nip therebetween, said apparatus comprising a generally cylindrical first roller having a surface, a circumference, and axes, the first roll comprising: a plurality of circumferential first ridges and circumferential first grooves on the surface of the roll, wherein the first ridges have a top surface and the first grooves have a bottom surface; and a plurality of spaced apart teeth extending outwardly from a top surface of the first ridge, each tooth tapering from the top surface to a tip, wherein the top surface of the first ridge is located on the between the ends of the teeth and the bottom surface of the first groove; and a generally cylindrical second roller including a plurality of continuous circumferential second ridges and circumferential second grooves.

The present invention also relates to a process for deforming a web using an apparatus comprising feeding a precursor web into a nip formed between two intermeshing rolls comprising : a) a generally cylindrical first roller having a surface, a circumference and an axis, the first roller comprising: a plurality of first ridges and first grooves, the first ridges and first grooves Grooves extend on the surface of the roll around the circumference of the roll, wherein the first ridge has a top surface and the first groove has a bottom surface; and a plurality of teeth spaced apart from the first ridge The top surface of the tooth extends outwardly, the tooth has a tip, wherein the top surface of the first ridge is disposed between the tip of the tooth and the bottom surface of the first groove; and b) a generally cylindrical first Two rolls, the second roll comprising a plurality of continuous circumferential ridges and circumferential grooves, wherein the second ridges have a top surface and the second grooves have a bottom surface; wherein when the web is fed When entering the nip, the tops of at least some of the ridges on the first roll extend inwardly toward the axis of the second roll beyond the tops of at least some of the second ridges on the second roll. depth, and the web:

(i) apertured by said teeth at spaced first locations to form a spaced plurality of apertures; and

(ii) stretched in the transverse direction by said intermeshing rolls.

Description of drawings

The accompanying drawings are included herein to facilitate a better understanding of the invention. The drawings illustrate the inventions described herein and together with the description serve to explain the claimed subject matter.

Figure 1 is a perspective view of a prior art pair of ring rolls for texturing a web.

Figure 2A is a perspective view of a prior art pair of rolls, a Roller Knife Aperturing (or "RKA") roll and a ring roll, for apertured webs.

Figure 2B is a side view of the pair of prior art rollers shown in Figure 2A.

Figure 2C is an enlarged side view of the nip between the rolls shown in Figure 2A.

Figure 2D is a top view of an exemplary prior art web that can be formed using the roll shown in Figure 2A.

Figure 3A is a perspective view of a pair of rolls, one of which is a staggered "ridge" RKA roll and the other roll is a ring roll, useful in the apparatus and methods described herein.

Figure 3B is an enlarged side view of the nip between the rolls shown in Figure 3A.

4A is a perspective view of a portion of the surface of an exemplary raised ridge RKA roll.

4B is a perspective view of a portion of the surface of an exemplary ring roll.

4C is a perspective view of a portion of the surface of an exemplary raised ridge SELM roll.

5A is a perspective view of a portion of the surface of another exemplary raised ridge RKA roll.

Figure 5B is a side view of the tooth arrangement shown in Figure 5A.

Figure 5C is an end view of the tooth arrangement shown in Figure 5A.

Figure 5D is a top view of the tooth arrangement shown in Figure 5A.

Fig. 5E is a cross-sectional view taken along the line D-D of the tooth arrangement shown in Fig. 5B.

Fig. 5F is a cross-sectional view taken along line E-E of the tooth arrangement shown in Fig. 5B.

Figure 6A is a front view of a first exemplary set of teeth where the teeth are tapered and truncated.

6B is a front view of a second exemplary set of teeth, where the teeth are tapered and half-truncated.

6C is a front view of a second exemplary set of teeth, where the teeth are tapered and untruncated.

Figure 7 is a schematic illustration of a tooth pattern in which end facet angle γ and ridge finishing can be achieved in a single helical machining step.

Figure 8 is an enlarged side view of a portion of the surface of an alternative raised ridge RKA roll.

Figure 9A is a top view of an example of a web that may be formed using a variation of the roll in Figure 3A.

Figure 9B is an enlarged view of one of the holes shown in Figure 9A.

Figure 10 is a side view of another embodiment of an apparatus for aperturing a web with three rolls in a planetary arrangement.

Figure 11 is a top view of a 25 gsm PE film web (film stretched/flattened to show areas of high and low basis weight).

Figure 12 is a top view of a 60 gsm PP nonwoven web (nonwoven stretched/flattened to show high and low basis weight regions).

Fig. 13 is a cross-sectional view of the fiber web shown in Fig. 12 .

Figure 14 is a side perspective view of another nonwoven web.

Figure 15 is a top perspective view of a nonwoven web.

Figure 16 is a cross-sectional view of a membrane web.

17, 18A and 18B are top views of the apertured film web of Example 1.

19A is a top perspective view of an apertured nonwoven web as described in Example 2. FIG.

Figure 19B is a bottom perspective view of the web of Figure 19A.

detailed description

A broad description of many different embodiments of the invention is set forth below. This description is intended to be construed as exemplary only, and does not describe every possible embodiment, since describing every possible embodiment would be impossible or impractical. And it should be understood that any feature, property, component, composition, ingredient, product, step or method described herein may be deleted, wholly or in part, and any other feature, property, component, composition described herein , composition, product, step or method combined or replaced by the latter. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. All publications and patents cited herein are hereby incorporated by reference.

It should also be understood that unless a term is expressly defined in this specification using the sentence "As used herein, the term '______' is hereby defined to mean..." or a similar sentence, no intention is made to express or imply the meaning of that term beyond their plain or ordinary meaning, and such terms should not be construed as limiting the scope based on any statement made in any part of this patent (other than the language of the claims). No term is essential to the invention unless so specified. When any term recited in this patent's appended claims is referred to in this patent in a manner consistent with a single meaning, it is for the sake of clarity so as not to confuse the reader, and is not intended to be implicit or otherwise Such claim terms are not intended to be limited to this single meaning. Finally, unless a claim element is defined by describing the word "means" and a function without describing any structure, there is no intent to interpret the scope of any claim element based on the application of the sixth paragraph of 35 U.S.C. §112.

The present invention enables the formation of an apertured web which is stronger in the transverse direction and thus less prone to tearing in the transverse direction. The present invention describes a process for producing an apertured web having discrete, closely spaced pores having a desired larger width in the transverse direction. The process is also capable of producing structures with alternating ridges and grooves, with holes contained in the grooves. The invention also describes an apparatus that will allow a web to be apertured with the desired discrete, closely spaced, larger width apertures in the transverse direction.

As used herein, the term "absorbent article" includes disposable articles such as sanitary napkins, pantiliners, tampons, interlabial devices, wound dressings, diapers, adult incontinence products, wipes, and the like. In addition, the absorbent members produced by the methods and apparatus disclosed herein are also applicable to other webs such as scouring pads, dry mop pads (such as pad) etc. At least some of such absorbent articles are intended for the absorption of bodily fluids, such as menses or blood, vaginal secretions, urine and faeces. The wipes may be used to absorb bodily fluids, or may be used for other purposes, such as for cleaning surfaces. The various absorbent articles described above will generally comprise a liquid-permeable topsheet, a liquid-impermeable backsheet joined to the topsheet, and an absorbent core between the topsheet and the backsheet.

As used herein, the term "absorbent member" refers to a component of an absorbent article that typically provides one or more fluid handling functions such as fluid acquisition, fluid distribution, fluid transport, fluid storage, and the like. If the absorbent member comprises an absorbent core assembly, the absorbent member may comprise the entire absorbent core or only a part of the absorbent core.

As used herein, the term "pore" means a hole. Holes may be punched cleanly through the web so that the material surrounding the holes lies in the same plane as the web prior to hole formation ("two-dimensional" holes), or holes may be formed in which at least some of the material surrounding the openings is pushed out of the plane of the web. In the latter case, these pores may resemble "three-dimensional" pores. Three-dimensional holes generally maintain a larger open area under an applied load. As used herein, the term "apertured" refers to a web comprising a plurality of apertures.

As used herein, the term "components" of an absorbent article refers to the individual components of the absorbent article, such as the topsheet, acquisition layer, liquid management layer, absorbent core or absorbent core layer, backsheet, and barriers such as barrier layers and barrier cuffs.

As used herein, the term "corrugated" or "corrugation" refers to a three-dimensional web topographical feature comprising an alternating plurality of generally parallel ridges and grooves, wherein the ridges and grooves surround (horizontally pass through the cross-section of the web) The drawn) axis X undulates. The ridges and grooves can be equally undulating on either side of the axis, or can be inclined to one side.

As used herein, the term "cross direction" or "CD" refers to the path in the plane of the web perpendicular to the machine direction.

As used herein, the term "deformable material" is a material capable of changing its shape or density in response to applied stress or strain.

As used herein, the term "depth of engagement" ("DOE") refers to the degree of engagement between two rollers. The distance is measured from the outermost ends of the teeth or ridges on the first roll to the outermost ends of the teeth or ridges on the second roll. As used herein, the terms "mesh" or "intermesh" refer to an arrangement in which the teeth/ridges on one of the rollers extend towards the surface of the other roller and some portions of at least some of these teeth/ridges are on the other roller. The teeth/ridges on the surface of one roll extend between and lie below an imaginary plane drawn through the ends of the teeth/ridges on the surface of the other roll.

As used herein, the term "discrete" means distinct or unconnected. When the term "discrete" is used in relation to teeth on a raised ridge roll, it means that the distal (or radially outermost) ends of the teeth are distinct or unconnected in all directions, including both longitudinal and transverse directions (even if the base of the tooth can be shaped to the same surface as the roller, for example). For example, ridges on a ring roll are not considered discrete.

As used herein, the term "disposable" describes absorbent articles and other products that are not intended to be laundered, or restored, or reused as absorbent articles or products (i.e., they are intended to be discarded after use, and preferably recycled utilization, composting or otherwise disposing of in an environmentally compatible manner).

As used herein, the term "hollow" describes the ridges and grooves present in webs produced by the apparatus and methods described herein. The ridges and grooves include voids that do not have web material. For example, a web includes ridges, grooves, and an X-axis drawn horizontally through a cross-section of the web; regions above the X-axis but below the tops of the ridges are hollow, or include hollow regions. Likewise, the area below the X-axis but above the bottom of the groove is hollow, or includes a hollow area.

As used herein, the term "machine direction" or "MD" refers to the path along which a material, such as a web, travels through a manufacturing process.

As used herein, the term "macroscopic" refers to structural features that are readily visible and distinctly discernible by a person with 20/20 vision when the vertical distance between the observer's eyes and the fiber web is about 12 inches (30 cm) or components. Conversely, as used herein, the term "microscopic" refers to features that are not easily seen and not clearly discernible under such conditions.

As used herein, the term "ring rolling" or "ring rolling" refers to a process using a deforming member comprising counter-rotating rolls containing at least some sections of continuous ridges and grooves, intermeshing belts, or intermeshing Engaging plates in which interengaging ridges (or protrusions) and grooves (or depressions) of deforming members engage and stretch a web inserted between them. Unless otherwise specified, the ring rolls alone did not aperture the web. For ring rolling, depending on the orientation of the ridges and grooves, the deformation members can be arranged to stretch the web in the cross direction, in the longitudinal direction or in a helical direction/at an angle to the cross or longitudinal direction. Examples described herein with respect to one orientation are intended to be understood as applicable to orientations other than the one described.

As used herein, the term "Roll Knife Aperturing" (RKA) refers to methods and apparatus using intermeshing deforming members or rollers, wherein one or more rollers include a plurality of teeth. The teeth may be sharp to cut through and deform the web to produce an apertured web, or in some cases, a three-dimensional apertured web, as disclosed in US 2005/0064136A1 and US 2006/0087053A1.

The term "structural elastic-like film" or "structural elastic-like film" refers to the Procter & Gamble technology, where SELF (structured elastic-like film) stands for Structural Elastic Like Film . Methods, apparatus, and patterns produced via SELF are illustrated and described in US Patent Nos. 5,518,801; 5,691,035; 5,723,087; 5,891,544; 5,916,663; While the process was originally developed using tooth geometries that deform polymer films without creating holes, other tooth geometries have been developed that are more favorable for forming tufts (in the case of nonwovens), or and a tent-shaped part (in terms of membrane) with holes on the rear end. A process for forming tufts with apertures in a nonwoven web using SELF is disclosed in US Pat. No. 7,682,686 B2.

As used herein, the term "teeth" refers to any element on the surface of a roll that is capable of opening a web.

I. Open cell fiber mesh material

Although the term "apertured web material" is used herein, it is intended that components such as absorbent members (or non-absorbent members) for absorbent articles be produced from such apertured web materials. In such cases, the apertured web material will be cut into individual components for the absorbent article (such as topsheet, backsheet, acquisition layer, absorbent core). In the case of webs for absorbent articles, such new structures may include those that provide improved properties, such as improved softness, fluid handling, or other properties, in predetermined portions of the web. These apertured webs can be cut to form various other components for packaged products (eg, flow wrap, shrink wrap, and plastic bags), wipes, facial tissues, toilet tissue, paper towels, and the like.

Discrete, closely spaced apertures of large width in the transverse direction, which cannot be produced with current methods and dies, can be provided in webs and assemblies formed from them. The new pores comprise larger open areas and lower aspect ratios (pore length:pore width) compared to pores of equivalent open area achievable via prior art techniques (see Figure 2D), which (in terms of membranes) resulting in increased fiber web strength.

In addition, webs produced with this new technology also have a unique, more textured appearance. The textured web may comprise alternating ridges and grooves, where holes are intentionally contained within the grooves. In the case of apertured webs used in absorbent articles, the webs can provide better fluid acquisition, breathability, or separation from the body, thereby promoting a drier, cleaner feel. For example, in sanitary napkins, apertures located in the grooves help direct and transfer fluid from the topsheet to the lower absorbent member. Not only do the holes provide these benefits, but any ripples present in the final web can additionally support these benefits. For example, corrugations provide at least partial non-contact with the body, which improves breathability, creates a dry feel, and facilitates less contact with wet/dirty surfaces that may irritate the skin or make the person feel uncomfortable. In the case of sanitary napkins, the corrugations can direct fluid longitudinally along the sanitary napkin and keep fluid away from the side edges of the sanitary napkin.

The web to be apertured (or "precursor web") may comprise any suitable deformable material, such as a woven material, a nonwoven material, a film, a flat film, a microtextured film, a combination of any of the foregoing, or laminate. As used herein, the term "nonwoven web" refers to a web that has a structure of individual fibers or threads that are sandwiched, but not in a repeating pattern as in a woven or knitted fabric, The woven or knitted fabric generally does not have randomly oriented fibers. The nonwoven web may or may not include thermal bond points. This may include paper stock such as tissue paper, dry stock, liner, filter paper, and combinations thereof. Nonwoven webs or fabrics have been formed by a number of processes, for example, meltblowing, spunbonding, hydroentanglement, air-laying, wet-laying, through-dry papermaking processes, and bonded carded web processes, including carded Comb heat bond. Depending on the forming process, the nonwoven web may or may not include thermal bond points. Film materials can be single layer, multilayer, embossed, or microtextured. The woven fabric, nonwoven fabric, film, combination or laminate may be made from any suitable material, including but not limited to natural materials, synthetic materials, and combinations thereof. Suitable natural materials include, but are not limited to, cellulose, cotton linters, bagasse, wool fibers, silk fibers, and the like. In some embodiments, the web of material may be substantially free of cellulose, and/or include no paper material. In other embodiments, the methods described herein can be performed on cellulose-containing precursor materials. Suitable synthetic materials include, but are not limited to, rayon and polymeric materials. Suitable polymeric materials include, but are not limited to: polyethylene (PE) (e.g., linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), etc.), polyester, polypara Ethylene Phthalate (PET), and Polypropylene (PP). Any of the above materials may include post-consumer recycled materials. The devices described herein are applicable to a wide range of materials and lower cost materials. For example, commodity spunbond nonwovens, multiple layers with different chemical and mechanical properties (and controlling the degree to which the two or more layers intermix), nonwovens with various a woven material; or a film. In addition, the equipment is capable of running directly in-line (and without loss of loft due to roll compression/storage).

Various polymers can be used to produce webs of interest. Potential materials include biopolymers made from non-petroleum sources such as bio-derived polyethylene (bio-PE), bio-derived polypropylene (bio-PP), bio-derived polyethylene terephthalate Ethylene glycol ester (bio-PET), and bio-derived poly(ethylene 2,5-furandicarboxylate) (bio-PEF). These materials may be partially or completely derived from at least one renewable resource, wherein a renewable resource refers to a natural resource that is renewable within a 100-year period. Renewable resources include plants, animals, fish, bacteria, fungi, and forestry products, and may be naturally occurring, hybrid, or genetically engineered organisms. Natural resources such as crude oil, coal and peat that take longer than 100 years to form are not considered renewable resources. Other polymers derived from non-petroleum sources include starch-based polymers and cellulose. In addition, recycled resins can be used 100% or blended with various resins, such as r-HDPE, r-LLDPE, r-LDPE, r-PET, r-PEF, or r-PP after consumer milling. Polymers derived from renewable resources and recycled resins can be used on their own or blended with petroleum-based polymers at varying levels to control costs. Sources and methods of preparing polymers from non-petroleum sources can be found in US 8,063,064 B1 and US 2011/0319849 A1.

The present invention relates to apertured web materials and apparatus and methods for apertured and stretched webs to produce such materials, which overcome one or more of the disadvantages of the prior art. Stretching or stretching the web is beneficial because it enables cost reduction by reducing the basis weight of the web as a whole. By performing aperture opening and stretching in the same process step, wider, more preferred apertures are produced in the web material. Here, opening and stretching are done in a single unit in an aligned manner such that the stretching is done while the teeth are still penetrating the material, thus not allowing the holes to collapse when stretched. The additional stretching step not only makes the pores wider, but also has the potential to create a web with a corrugated appearance. This combination of opening and subsequent stretching must be precisely aligned. If hole opening and stretching are performed in separate steps, as in the prior art, the holes will not be aligned with the stretch ring rolls and the holes may close. Additionally, the webs produced with this new process are softer and more drapable (loose and/or thinned fibers and/or films) due to stretching. Thinner webs are generally desirable because they are able to hold less fluid. This is important when the fibrous web is used as the topsheet of an absorbent article because there is less saturation in the topsheet.

In one non-limiting example, an apertured web material includes a web having discrete pores formed therein. The fiber web has a first surface and a second surface opposite the first surface. The web includes a substantially non-apertured region or matrix surrounding a plurality of discrete pores.

These pores are densely packed in a relatively small area. For example, the center-to-center spacing between holes may be less than or equal to about 20 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, or 0.5 mm in any direction. The total number of holes in an area of 1 square inch (645 mm ² ) may be greater than or equal to 4, 25, 100, 250, 500, 1000, or 3000. The number of holes in a one-inch square area can be determined by marking a square area on the material with a fine-point pen or marker pen and measuring 1 inch (25.4 mm) The number of first holes, second holes, third holes, etc. located within or on the border of the 1 inch square is counted. If desired, a low power microscope or other magnification aid can be used to aid in the visualization of the pores in the material. The pores may be of any suitable configuration.

The holes can be of any suitable size. Typically, the pores will be macroscopic. The plan view area of the holes may be greater than or equal to about 0.5 mm ² , 1 mm ² , 5 mm ² , 10 mm ² , or 15 mm ² . The methods described herein can also be used to create microscopic pores, which have a plan view area of less than 0.5 mm ² .

In addition to holes, the web may also include alternating ridges and grooves, with the holes located in the grooves. The ridges may extend continuously or form discontinuous ridges in the deformed regions of the web. The groove may extend continuously, with the holes spaced at regular intervals within the groove. It should be noted that if the web is turned upside down, the grooves will become ridges and the ridges will become grooves, and the holes will now be located in the ridges. Depending on process and material parameters, the pores can be two-dimensional or three-dimensional. For a three-dimensional hole, the base of the hole will extend in the opposite direction of the ridge. The ridge sides and groove sides are oriented to a greater extent in the z-direction than the ridge tops and groove bottoms.

In the case of films, the ridge sides and groove sides can be thinner and have a lower basis weight than the ridge tops and groove bottoms due to the stretching process. This results in a web having alternating regions of higher caliper and basis weight and regions of lower caliper and basis weight, wherein the regions of higher caliper and basis weight are located in the ridge tops and groove bottoms and have lower caliper and basis weight. The heavy areas are located in the side walls between them. Alternating basis weights provide thinned/flexible areas for comfort and maintain thickness for strength.

In the case of nonwovens, the basis weight is also reduced in the stretch zone, which again results in a web having alternating areas of higher basis weight and lower basis weight, with the higher basis weight areas being at the top of the ridges and in the bottom of the groove, and the region of lower basis weight in the sidewall between them. In the case of nonwovens, the web thickness may not decrease in the stretch zone because the fibers can untangle and move away from each other. However, the thickness of some of the individual fibers may decrease due to stretching, resulting in a fiber diameter in the range of 40% to 80% of the original fiber diameter. The average fiber diameter at the top of the ridges and the average fiber diameter at the bottom of the grooves may be greater than the average fiber diameter at the sidewalls. Although the teeth locked at the ridges and grooves, the base web thickness did not change significantly. Although the web is textured, the thickness of the web locally at the ridges and grooves does not change significantly, as the ridges and grooves are not filled but instead form hollow areas as they have been deformed to a flat surface outside. Hollow ridges are not able to retain as much fluid as filled ridges, which can provide a dry benefit when used as a topsheet in an absorbent article. Due to stretching, the web is permanently elongated in the direction of stretching. Suitably, the web thickness in the stretch zone is 20% to 80% of the initial web thickness.

II. PRIOR ART APPARATUS FOR DEFORMING WEB MATERIALS

The methods of the prior art are not suitable for producing holes with wider dimensions in the transverse direction, especially for tough or tear-resistant films. Therefore, it is desirable to devise a process that enables aperturing and stretching to be performed in the same process step (i.e., in the same nip and while the aperture teeth are still penetrating the web) to obtain in the web material Pores having larger dimensions in the transverse direction than can be obtained with prior art methods. Prior art methods are also not suitable for producing webs with alternating ridges and grooves with the holes located in the grooves using high speed aperture and stretching devices such as those described herein.

Figure 1 shows a first prior art apparatus 10 in which rolls 12 and 14 are referred to herein as ring rolls. As in the case of the rollers in the other apparatus shown and described herein, the rollers 12, 14 are carried on respective rotatable shafts having axes of rotation A arranged in parallel relationship. In all of the embodiments described herein, the rollers are non-contact and axially driven. In this embodiment, the surface of the roller has a plurality of alternating grooves 16 and ridges 18 extending around the circumference of the roller. In other embodiments, the ridges and grooves may extend parallel to the axis A of the roll. One or more such rollers may be used in various embodiments of the apparatus described herein.

In the embodiment shown in FIG. 1 and various other embodiments described herein, the rollers mesh or at least partially mesh with each other. As shown in Figure 1, the rollers generally rotate in opposite directions (ie, the rollers are counter-rotated). This is also true for the other embodiments described herein.

Figures 2A-2C illustrate a second prior art apparatus 20 in which the top roll 22 is a Roll Knife Apertured (or "RKA") roll and the bottom roll 24 is referred to herein as a ring roll. The apparatus comprises a pair of counter-rotating intermeshing rollers, wherein the top roller 22 includes pyramidal teeth 30 having four or more sides that are substantially triangular and tapered from the base toward the tip, and the bottom roller 24 Circumferentially extending grooves 26 and ridges 28 are included. The teeth 30 are arranged in spaced circumferential rows with grooves between the rows. Teeth 30 extend from top roll 22 at bases, and the bases of the teeth have a cross-sectional length dimension that is greater than a cross-sectional width dimension. Typically, apertures are formed in the web material when the teeth 30 on the RKA roll 22 intermesh with the grooves 26 on the ring roll 24 . With regard to tooth height, pitch, pitch, depth of engagement, and other process parameters, the homing and homing equipment may be the same as described in US Patent Application Publication US 2006/0087053 A1.

The RKA roll 22 shown in FIG. 2A includes a staggered (vs. standard) tooth pattern. As used herein, the term "staggered" means that adjacent teeth are not laterally aligned in rows. As used herein, the term "normal" means that adjacent teeth are aligned in transverse rows and thus non-staggered. As shown in FIG. 2C , rolls 22 and 24 are laterally aligned such that teeth 30 on RKA roll 22 align with grooves 26 on ring roll 24 . As the teeth 30 penetrate the web, the ridges on the mating ring roll 28 support the web so that the teeth 30 can penetrate the web while simultaneously forming holes in the opposite direction. Figure 2D shows a top view of an exemplary prior art web 34 that can be produced by equipment similar to that shown in Figures 2A-2C. The resulting web 34 includes a matrix 36 surrounding apertures 38 . Aperture 38 formed by prior art apparatus like that of FIGS. 2A-2C includes a length L in the longitudinal direction and a width W in the transverse direction. These holes are usually slit-like, having a width W that is much smaller than the length L, especially for tougher and more resilient webs.

III. Apparatus and Method for Aperturing Web Material Using Teeth Extending from Raised Ridges

Generally, the apparatus includes two intermeshing forming structures forming a nip therebetween. The forming structure may include rolls, plates, belts, sleeves, other structures capable of imparting texture to the web, or combinations thereof. The first forming structure includes a first plurality of ridges and first grooves on a surface of the forming structure, wherein the first ridges have a top surface and the first grooves have a bottom surface. The first forming structure also includes a plurality of spaced apart teeth extending outwardly from a top surface of the first ridge, each tooth being capable of forming a hole, wherein the top surface of the first ridge is located between the ends of the teeth and between the bottom surfaces of the first groove. The second shaped structure includes a plurality of continuous second ridges and second grooves.

More specifically, the apparatus comprises a single pair of counter-rotating, intermeshing rolls forming a single nip N therebetween. Although, for convenience, these devices will be described herein primarily in terms of rollers, it should be understood that the description will apply to any suitable device that may include any suitable type of forming member, including but not limited to: a pair of rollers ; pairs of plates; conveyors with elastic discs (or small plates); belts; or combinations thereof. The first and second rollers each include a surface 106, 108 that includes a plurality of circumferentially extending ridges and grooves. Alternatively, the ridges and grooves may extend in a direction parallel to the axis of the roll as long as it is paired with a roll having ridges and grooves extending in the same direction. The first roller additionally includes a plurality of teeth spaced apart, wherein the teeth extend outwardly from the top surface of the ridge. This creates "ridges". The ridges of the second roll extend toward the axis of the first roll to a depth beyond the tops of at least some of the ridges on the first roll. In this way, the initial engagement of the teeth creates a hole which is then stretched transversely as the engagement proceeds to a depth below the ridge. By first performing the aperture in one process step followed by stretching while the teeth are still penetrating the web, the resulting apertures are significantly shorter than those produced by standard toothed rolls as described above and shown in Figures 2A-2D. It has a larger width in the horizontal direction.

The pores of the present invention comprise a lower aspect ratio (pore length:pore width) and a much higher open area than prior art pores, especially when used in tougher membranes, e.g. containing high levels of Those of LLDPE. The new tooth geometry facilitates high open area at lower mold temperatures, enabling the formation of apertures in webs that cannot be apertured with conventional tooth geometries. The new die geometry provides the ability to aperture the web at lower temperatures (eg, between 35 and 70 degrees Celsius) or even at ambient temperature without the need to heat the equipment. In addition, the costs involved to produce this mold are minimal or low relative to previous molds, since in particular less metal is removed. Thus, room temperature precursor webs can be used. In one embodiment, the precursor web and the intermeshing rolls are not heated. Alternatively a generally preheated web may be used. Or zoned preheating of the web may enable the formation of pores in some zones and bubbles in other zones. Preheating can be accomplished by wrapping the RKA roll prior to splicing (where varying wrapping times may be used prior to splicing) or by wrapping the ring roll prior to splicing. Also, heated or non-heated molds can be used. Suitably, the web is heated by wrapping an RKA roll heated to 50-200 degrees Celsius, or 50-100 degrees Celsius. The RKA roll and the ring roll may be driven at the same outermost surface speed, or there may be a speed difference between the two rolls.

The following figures show non-limiting examples of specific roll arrangements and apertured web materials that may be formed thereby. These devices are able to utilize a single nip and run at higher process speeds, in some cases without heating, and are less expensive than prior art methods for aperture and stretching (e.g., because they are Simple mechanical process - only two intermeshing rollers).

Figures 3A and 3B illustrate an exemplary apparatus 100 of the present invention comprising a single pair of counter-rotating intermeshing rolls 102, 104 forming a single nip N therebetween. The first (top) roll 102 is a variation of the RKA roll shown in Figure 2A. This particular variation will be referred to herein as a "raised ridge RKA roll". The second (bottom) roll 104 in the apparatus 100 shown in Figures 3A and 3B is a ring roll.

As shown in FIG. 4A , the first roller 102 includes a plurality of grooves 110 and ridges 120 , and a plurality of staggered spaced apart teeth 130 extending outwardly from a top surface 122 of the ridges 120 . The roller 104 is configured such that the top surface 122 of the ridge 120 is disposed between the tip 134 of the tooth 130 and the bottom surface 112 of the groove 110, depending on the orientation relative to the axis A of the roller. As shown in FIG. 4B , the second roller 104 includes a plurality of grooves 140 and ridges 150 . The groove 140 has a bottom surface 142 and the ridge 150 has a top surface 152 . Here, the distance between the top surface 152 of the ridge 150 and the bottom surface 142 of the groove 140 is substantially the same around the circumference of the roller. Figure 4C is an alternative second roll 104B in the form of a staggered-ridge LSELM roll. The roller 104B is configured such that the top surface 122 of the ridge 120 is disposed between the tip 134 of the tooth 130 and the bottom surface 112 of the groove 110, depending on the orientation relative to the axis A of the roller. Referring back to FIGS. 3A and 3B , the teeth 130 and ridges 120 of the first roller 102 extend toward the axis A of the second roller 104 intermeshing to a depth beyond the tops 152 of at least some of the ridges 150 on the second roller 104 .

Teeth suitable for this process must facilitate the opening of the fiber web. The teeth on the rollers may have any suitable configuration. A given tooth may have the same plan length and width dimensions (such as a tooth with a circular or square plan). Alternatively, a tooth may have a length that is greater than its width (such as a tooth with a rectangular plan view), in which case the tooth may have any suitable aspect ratio of its length to its width. Suitable configurations for the teeth include, but are not limited to: teeth with triangular side views; teeth with square or rectangular side views; cylindrical teeth; pyramidal teeth; , polygonal, etc. planar configuration teeth; and their combinations. Polygons include, but are not limited to, rectangles, triangles, pentagons, hexagons, or trapezoids. The sidewalls of the teeth may taper at a constant angle from base to tip, or they may vary in angle. The teeth may taper towards a single point at the tip of the tooth, such as the tooth shown in Figure 4A. The teeth may have rounded, flat or pointed ends. Alternatively, the teeth may taper toward a multipoint, elongated tooth tip, such as the SELM tooth shown in Figure 4C. However, the tip of the tooth must form an apex with at least one of the vertical walls of the tooth (eg, the vertical walls on the front and rear ends of the tooth, as shown in FIG. 4C ), so the tooth perforates or pierces the web. For the teeth shown in Figure 4C, each tooth may form 2 holes, one at the leading edge of each tooth and the other at the trailing edge.

In an exemplary embodiment shown in FIGS. 5A-F , the first roller 102 includes a plurality of pyramid-shaped teeth 130 extending outwardly from the top surface 122 of the ridge 120 . 5A is a perspective view of a portion of the surface of another exemplary raised ridge RKA roll. Figure 5B is a side view of the tooth arrangement shown in Figure 5A, Figure 5C is an end view, and Figure 5D is a top view. FIG. 5E is a cross-sectional view taken along line DD of the tooth arrangement shown in FIG. 5B. Fig. 5F is a cross-sectional view taken along line EE of the tooth arrangement shown in Fig. 5B. The tooth cross-sectional area A _t shown in FIG. 5E is smaller than the tooth cross-sectional area A _tb shown in FIG. 5F . The sides (eg, 130a - 130f shown in FIG. 5E ) are substantially triangular and taper at a constant angle from tip 134 to base 132 . The number of sides can be four (eg, FIG. 4A ), six (eg, FIGS. 5A-6C ), or another number less than or equal to twelve. The teeth 130 are arranged in spaced circumferential rows with grooves 110 between the rows. The longitudinal end-to-end pitch S _MD is 0.4mm to 15mm (or 3mm to 8mm). The transverse pitch P is 0.4mm to 10mm (or 1mm to 3mm). The teeth have an included angle α of 30 to 90 degrees (or 45 to 65 degrees), a sidewall angle β on the long sides (eg, 130c, 130f) of the teeth of 3 to 15 degrees, and 45 to 120 degrees (or 60 to 60 degrees). 90 degrees) between the leading and trailing edges of the tooth's terminal facet angle γ (eg, the angle between sides 130a and 130b or the angle between sides 130d and 130e). In some cases, when producing teeth by helical grinding, longitudinal and transverse tooth pitches are chosen that are staggered and include a terminal facet angle γ.

There are different ways to finish the portion 136 where the tooth 130 and the ridge surface 122 meet, for example, truncated ( FIG. 6A ), where the taper on each side is truncated by some plane; Figure 6B), where the taper on at least one side is truncated by some arc; or non-truncated (Figure 6C), where the taper on each side is not truncated in any way. The tooth 130 shown in FIG. 6A tapers from a tip 134 toward a base 132 and has a truncated lower portion 136 . Can be tapered and/or truncated in various degrees. The truncated taper on the tooth makes the tooth easier to manufacture. In this case, see FIG. 7 , as is well known in forming operations, the end facet angle γ and ridge finish can be achieved in a single helical machining step by rotating in the circumferential direction D _C die, while advancing machining in the axial direction of the die. Following the machining path _MP will produce the end facet of the tooth 130 . For the tooth interlace T _S , the included tip facet angle γ is thus produced as 2*Arctan (transverse tooth pitch “P”/tooth interlace “T _S ”).

The top surface 122 of the ridge between the teeth 130 can be finished in different ways. For example, surface 122 may be radiating or non-radiating. A radial surface will protect the web from tearing during formation, especially with films; a non-radiative surface such as surface 122 shown in Figures 6A-6C may be more cost effective.

The raised ridge RKA roll 102 is configured such that the top surface 122 of the ridge 120 is disposed between the tip 134 of the tooth 130 and the bottom surface 112 of the groove 110 , depending on the orientation relative to the axis A of the roll 102 . The tooth height h _t is defined as the distance between the tip 134 of the tooth 130 and the bottom surface 112 of the groove 110 . The tooth height h _t is 1 mm to 12 mm, or 2 mm to 8 mm, or 3 mm to 6 mm. The ridge height _hr is at least 20% of the tooth height, usually 20% to 95%. The depth of cut d _cc is defined as the distance between the tip 134 of the tooth 130 and the top surface 122 of the ridge 120 . In this embodiment, the distance between the tips 134 of the teeth 130 and the top surface 122 of the ridge 120 is substantially the same around the circumference of the roller. The depth of crosscut d _cc depends on the amount of deformation required to form the hole. For example, the depth of incision d _cc may be in the range of 0.2 mm to 9 mm, or 1.0 mm to 4.0 mm, or 2.0 mm to 3.5 mm. A smaller depth of crosscut d _cc (at the same DOE) produces a larger open hole. The depth of engagement of the pair of rollers 102, 104 must be greater than the depth of cut d _cc . Suitably, the depth of engagement is at least 0.1mm or 0.3mm greater than the depth of incision. The DOE at the nip N is 0.5mm to 10mm, or 3mm to 7mm, or 3mm to 4mm.

The ridge height h _r is defined as the distance between the top surface 122 of the ridge 120 and the bottom surface 112 of the groove 110 . In some embodiments, such as those shown in FIGS. 3B and 4A , the first roller 102 includes a transverse width, and the distance between the top surface 122 of the ridge 120 and the bottom surface 112 of the groove 110 is around the circumference and across the roller 102 The lateral widths are substantially the same. Or the distance between the top surface of the first ridge and the bottom surface of the second groove may vary around the circumference or across the transverse width of the first roller. Various alternative embodiments of the ridge roller are possible. For example, as shown by roller 162 in FIG. 8 , the height h _r of the ridges may vary between at least some of the teeth 168 . The ridge height h _r depends on the amount of deformation required to form the desired hole. The top surface 166 of at least one ridge 164 located between a pair of teeth 168 will have a height h _r1 that is at least 10%, 20%, or 30% greater than another ridge located between another pair of teeth 168 164 height h _r2 . This roll 162 may be used in a process such as that shown in FIG. 3A in place of the raised ridge RKA roll 102 . The second roll may be a ring roll with ridges of different heights in the circumferential or axial direction.

FIG. 9A shows an example of a web 170 that may be produced by the apparatus shown in FIG. 3A : an RKA raised roll with a staggered tooth pattern is used as the upper roll 102 and a ring roll is used as the lower roll 104 . Rollers 102 and 104 are laterally aligned such that teeth 130 on first roller 102 align with grooves 140 on second roller 104 . As the teeth 130 on the first roll 102 penetrate the web 170, the ridges 120 between the teeth 130 on the RKA raised ridge roll 102 support the web 170 so that the ridges 150 on the second roll 104 can pass through the web 170. The web 170 is stretched in the transverse direction.

A web in its initial state can be considered relatively flat and composed entirely of non-apertured regions. The web 170 has a first surface 170A and a second surface 170B. As the web is fed in the machine direction into a nip N between rolls (such as those shown in FIG. 3A ), the web is: (i) perforated by teeth 130 of first roll 102 to form spaces and (ii) stretched by the spine 120 of the first roll 102 to stretch the holes 172 in the transverse direction. The result is an apertured web 170 comprising apertures 172 and a matrix 174 surrounding the apertures 172, as shown in FIG. 9A, a top view of the web. Holes 172 may be pushed out of the plane of web 160 in one direction (downward, as viewed in FIG. 9A ), so holes 172 may have a height H _a . The holes 172 are aligned in rows in the longitudinal and transverse directions. FIG. 9B shows an enlarged top view of a single hole 172 . Aperture 172 includes a length La in the longitudinal direction and _{a width W a in} the transverse direction. The apertures will preferably have an aspect ratio AR of length divided by width of 1 to 4, or 1.25 to 3, or 1.5 to 2.5, or 1.6 to 2.3. Aperture 172 also includes each open area A _a and a perimeter surrounding open area P _a . The apertured web comprises a total open area of 5% to 25%, or 9% to 21%, or 10% to 16%, or 14% to 20% of the total web area. The apertured film comprises a tear or tensile strength (per 25.4 mm) in the transverse direction in the range of 1.5N to 5N, 2N to 4N, 2.5N to 4N, 2.5N to 3.5N, or 2.7N to 3.9N. Apertured nonwovens include a tensile strength in the cross direction (per 25.4 mm) in the range of 2N to 20N, or higher. In one example, the web includes a machine direction orientation and a transverse direction orientation, wherein the apertures include a length in the machine direction and a width in the transverse direction, and wherein the plurality of apertures include an aspect ratio of length divided by width of 1 to 4.

In some embodiments, the stretching step described above not only increases the transverse width of the pores, but also creates alternating ridges and grooves in which the pores are located. The parts of the web in contact with the ridges on the two rolls are frictionally locked on top of the ridges and are not stretched, while the web between the ridges is stretched out of plane. Portions of the web that are stretched out of plane become more oriented in the z-direction. Thus, a web can be formed having ridges and grooves, with holes located in the grooves. It should be noted that if the web is turned upside down, the grooves will become ridges and the ridges will become grooves, and the holes will now be located in the ridges. Fibers at the top of the ridges and fibers at the bottom of the grooves may be oriented to a greater extent in the X-Y plane than fibers at the sidewalls.

In the case of a film, the web is thinned and the basis weight is reduced in the stretch zone, while the web thickness and basis weight remain constant in the zone where the web is frictionally locked to the crest. This results in a web having alternating regions of higher caliper and lower caliper, and regions of alternating higher and lower basis weight, with the regions of higher caliper and higher basis weight being at the top of the ridges and the bottom of the grooves , and a region of lower thickness and lower basis weight is located in the sidewall between them. Figure 11 is a top view of a 25 gsm PE film web 210 (film stretched/flattened to show high basis weight regions 212 and low basis weight regions 214). The web 210 also shows ridges R, grooves G, and side walls S. As shown in FIG. A hole 216 exists in the groove G. As shown in FIG. As can be seen, the high basis weight regions 212 are located in the ridges R and grooves G, while the low basis weight regions 214 are located in the sidewalls S. FIG.

In the case of nonwovens, the basis weight is also reduced in the stretch zone, which again results in a web having alternating regions of higher and lower basis weight, with the higher basis weight regions being at the top of the ridges and the valleys. in the bottom of the tank, and a region of lower basis weight in the side walls between them. Figure 12 is a top view of a 60 gsm polypropylene nonwoven web 220 (nonwoven stretched/flattened to show high basis weight regions 222 and low basis weight regions 224). The web 220 also shows ridges R, grooves G, and side walls S. As shown in FIG. A hole 226 exists in the groove G. As shown in FIG. Thermal or fusion bond points 228 may be present in various locations on web 220 . As can be seen, the high basis weight regions 222 are located in the ridges R and grooves G, while the low basis weight regions 224 are located in the sidewalls S. FIG. In the case of nonwovens, the web thickness may not decrease in the stretch region because the fibers can untangle and move away from each other. However, the thickness of some of the individual fibers may decrease due to stretching. It should be noted that the "area" of a web used to characterize basis weight does not include the pores themselves.

Due to stretching, the web is permanently elongated in the direction of stretching. If the web is maintained in its corrugated state, most of the increased web width is filled by the ridges and grooves formed in the web. Alternatively, tension may be applied to stretch the web, which will cause the height and frequency of the ridges and grooves to decrease, and reduce the overall basis weight of the web. If desired, the web can be stretched such that the ridges and grooves are no longer present, and the web returns to its flattened state. The texturing process can stretch or grow the web by 10%, 15%, 20%, 25%, or more in the cross direction. The amount of permanent stretch and formability of the ridges and grooves depends on the mold geometry, process conditions and properties of the material. Typically, the process will permanently stretch or grow the nonwoven web material more than the film material. For example, the web may grow from 165mm to 190mm in the cross direction. Suitably, the web has an initial web basis weight region and a lower basis weight region, the lower basis weight region having a basis weight that is lower than the initial web basis weight.

13 is a cross-sectional view of the web 220 shown in FIG. 12 showing the ridges, grooves G, and axis X drawn horizontally through the cross-section of the web; the region above the X-axis but below the crests of the ridges is hollow, or includes a hollow area HA. Likewise, the area below the X-axis but above the bottom of the groove is hollow, or comprises a hollow area HA. Suitably, the thickness of the web at the top of the ridge and the thickness of the web at the bottom of the groove are similar. The web thickness at the top of the ridges and the web thickness at the bottom of the grooves may be similar to the web thickness at the sidewalls. By similar, it is meant that the thicknesses are within about 60% of each other. Or the web thickness at the top of the ridge and the web thickness at the bottom of the groove is greater than the web thickness at the sidewalls. FIG. 14 is a side perspective view of another nonwoven web 230 having ridges 232 , grooves 234 , and sidewalls 236 . Figure 15 is a top perspective view of a 28 gsm polyethylene/polypropylene bicomponent nonwoven web 240 comprising ridges 242 and grooves 244 and apertures 246, wherein aperture width W _a is greater than ridge width W _r . 16 is a cross-sectional view of film web 250 showing greater thinning at sidewalls 256 than at the tops of ridges 252 or bottoms of grooves 254 .

The processes of interest here may also utilize multiple deformation steps in order to deform the material more gently or to impart a greater amount of permanent deformation. Such multiple deformation steps may be performed by any suitable apparatus described in US Patent Application Serial No. 13/094,195 to Lake et al. Suitably, at least the first roll or the second roll also forms a nip with one or more additional rolls to further stretch or deform the web. In one arrangement 200 as shown in Figure 10, a ring roll 202 is paired with a ridge roll 204 which in turn is paired with another ring roll 206 such that the rolls are in a planetary or satellite configuration. The process utilizing multiple deformation steps may also be carried out on equipment with a relatively small number of rollers in a nested arrangement, or such as a hybrid with any suitable number of rollers, in order to effect the desired deformation. , closed-loop and shared row and other equipment.

Numerous alternative embodiments of apertured web materials and processes for their manufacture are possible. For example, web materials may be provided that have different regions (including deformed and/or undeformed regions) across surfaces having different characteristics. These regions may be selected by at least one characteristic from: ridge height, ridge spacing, pore size, fiber diameter, membrane thickness, or combinations thereof. In one embodiment, an apertured web material may be provided having aperture regions, and in some cases, ridge regions and groove regions. The webs disclosed herein may contain apertures of different sizes and/or ridge and groove regions of different sizes and frequencies. A fiber web may comprise one or more layers. In another embodiment, the film is a microtextured film comprising stretched regions and unstretched regions, wherein the stretched regions have different microtexture properties than the unstretched regions, and wherein the microtexture properties are selected from Opening area, size, orientation, and combinations thereof. Webs produced by the methods and apparatus described herein may include ridges extending discontinuously across the deformation zone, or ridges extending continuously across the deformation zone. To produce such apertured web materials, the ring rolls used may include land and groove regions. Or the ring roll may have regions where the ridges are of different heights, resulting in different depths of engagement (DOE), different depths below the ridges, and thus holes with different widths and open areas. Alternatively or in addition, the raised ridge roll may also include different zones, wherein the ridge heights are different in the different zones.

example

Example 1

In a non-limiting example for making pores in a polymeric film such as the web 300 shown in FIG. The ring rolls intermesh with 1.5mm pitch raised ridge HKA rolls for the device. The raised ridge RKA roll has teeth oriented such that the length direction extends in the longitudinal direction. These teeth are arranged in a staggered pattern, as shown in Figure 5A. These teeth have the shape of a pyramid with 6 sides tapering from the base to the tip at the tip and have a height _ht of 4.7mm. These teeth have an included angle of 62 degrees (α in Figure 5B), a sidewall angle on the long side of the tooth of about 6 degrees (β in Figure 5C), and a terminal facet angle of 90 degrees (α in Figure 5E). gamma). The ridges spanning between the teeth on the RKA roll are non-radial and form a flat surface. The teeth are finished in a half-truncated pattern at the ridges, as shown in Figure 6B. The ridges and grooves extend circumferentially around the ring roll.

There are two different tooth segments on the roll which are exhibited to demonstrate the benefit of the raised ridges and are referred to individually as "Segment A" and "Segment B". Segment A had a longitudinal pitch S _MD of 4.9 mm tip-to-tip, a cross-cut depth (d _cc in Figure 6A ) of 3.6 mm and a resulting ridge height (h _R in Figure 6A ) of 1.1 mm. Section B has a longitudinal pitch S _MD of 3.7 mm tip to tip, a depth of cut d _cc of 2.7 mm, and a resulting ridge height h _r of 2.0 mm.

The paired ring rolls were 1.5 mm pitch, had a height of 4.8 mm, a tip radius of 0.12 mm, and a side wall angle of about 4 degrees. Both rolls have a diameter of about 205 mm and are heated to 80 degrees Celsius. The RKA and ring rolls are laterally aligned such that the gap on both sides of the teeth is approximately equal.

The precursor web was a microscopically apertured polymer film having a basis weight of 26 g/m ² with a blend of LLDPE and LDPE, commercially available from RKW-Group (Germany). LLDPE comprises about 60% of the film composition, about 30% of LDPE, and the remaining 10% is inerts and fillers such as _TiO2 and its carrier resin. The microscopic pores were 55 mesh (number of pores per inch in the orthogonal direction) and they were arranged in an equilateral triangle pattern with a center-to-center spacing of approximately 462 microns. The hole diameter is 175-200 microns and the tapered cone height is about 120 microns.

The precursor web was pre-wrapped on ring rolls before being passed between intermeshing rolls at a linear web speed of 480 meters per minute. The microscopic aperture cone side of the film was placed facing the RKA roll. Use an engagement depth of 3.8mm. The resulting film is shown in Figures 18A and 18B at low magnification. Open area (percentage of film area with open pores), pore length, and pore width of the film are measured with a vision system, such as that available from Cognex Corporation (Natik, Massachusetts) under the IN-SIGHT tradename. A comparison of the open area, length and width of the pores from section A (Fig. 18A) and the pores from section B (Fig. 18B) is shown in the table below. 18A and 18B show membrane webs 320,340 having microscopic apertures 322,342 and apertures 324,344.

Example 2

In one non-limiting example for making a corrugated web having holes in the grooves, an apparatus comprising 2.0 mm 2.0 mm pitch ring rolls intermeshed with 2.0 mm pitch at a 6.3 mm depth of engagement may be used. Pitched ridge homing rolls. The raised ridge RKA roll has teeth oriented such that the length direction extends longitudinally, and the ridges and grooves extend circumferentially around the ring roll. The teeth are arranged in a staggered pattern, as shown in Figure 5A. These teeth have the shape of a pyramid with 4 sides tapering from the base to the tip at the tip and have a height _ht of 6.9 mm. These teeth had an included angle (α in FIG. 5B ) of 57 degrees and a sidewall angle on the long side of the tooth (β in FIG. 5C ) of about 5 degrees. The ridges spanning between the teeth on the RKA roll are not rounded and form a flat surface. The teeth are finished in an untruncated pattern at the ridges, as shown in Figure 6C. These teeth had a longitudinal pitch S _MD of 8.0 mm tip-to-tip, a cross-cut depth (d _cc in Figure 6A ) of 3.7 mm and a resulting ridge height (h _R in Figure 6A ) of 3.2 mm.

The paired ring rolls were 2.0 mm pitch, had a height of 6.9 mm, a tip radius of 0.12 mm, and a side wall angle of about 4 degrees. Both rolls have a diameter of about 142mm. The RKA and ring rolls are aligned laterally so that the gaps on either side of the teeth are approximately equal.

The first precursor web was a polymeric film having a basis weight of 25 g/m2 having a blend of LLDPE and LDPE, commercially available from Clopay Plastics Co. (Ohio). The precursor web was pre-wrapped on ring rolls before being passed between intermeshing rolls at a linear web speed of 20 meters per minute. The resulting corrugated apertured film is shown in Figure 11 (film stretched/flattened to show high and low basis weight regions). Images were acquired at low magnification using an optical microscope, such as that available from Allasso Industries, backlit with a red LED.

The second precursor web was a thermally bonded polypropylene nonwoven having a basis weight of 60 g/m2, commercially available from Fiberweb (France). The precursor web was pre-wrapped on ring rolls before being passed between intermeshing rolls at a linear web speed of 20 meters per minute. The resulting corrugated apertured nonwovens are shown in Figure 12 (top view; web stretched/flattened to show high and low basis weight regions), Figure 13 (cross-sectional view), Fig. 19A (ridge hob opening side), and Figure 19B (ring roll side). Images were acquired at low magnification using an optical microscope such as that available from Allasso Industries. The web 400 in FIGS. 19A and 19B includes alternating ridges 402 and grooves 404 ; holes 406 are present in the grooves 404 .

Dimensions and numerical values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range around that value. For example, a dimension disclosed as "40mm" is intended to mean "about 40mm". Moreover, recitations of numerical ranges herein include each discrete numerical value falling within that range as well as any other narrower ranges. It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference. Citation of any document is not to be construed as an admission that it is available as prior art to the present invention. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of that term in a document incorporated by reference, the meaning or definition assigned to that term in this written document shall control.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims (8)

1. it is a kind of for make fleece deform equipment, the equipment include two intermeshing reverse rolls, described two phases Mutually the reverse roll of engagement forms between the two roll gap, and the equipment includes：

A) the first roller of general cylindrical, first roller has surface, circumference and axis, and first roller includes：

The ridge of multiple circumferences first and circumferential first groove on the surface of the roller, wherein first ridge has top surface, And first groove has lower surface；With

Multiple teeth spaced apart, the tooth stretches out from the top surface of first ridge, and each tooth is from the top table Face to end is tapered, wherein the top surface of first ridge is located at the end of the tooth and the lower surface of first groove Between；With

B) the second roller of general cylindrical, second roller includes multiple ridges of continuous circumference second and circumferential second groove,

The a height of 1mm to 12mm of wherein described tooth,

Wherein described first roller includes the crosscutting depth measured from the end of the top surface to tooth of first ridge, wherein The roll gap includes the depth of engagement between first roller and second roller, and the wherein described depth of engagement more than described Crosscutting depth, and

Wherein described first ridge has height, wherein the height is at least the 20% of the height of the tooth.

2. equipment according to claim 1, wherein the roll gap includes nibbling between first roller and second roller Depth is closed, wherein the depth of engagement is 3mm to 4mm.

3. the equipment according to claim 1 or claim 2, wherein first roller includes transverse width, and wherein Around the circumference and across the bottom of the transverse width of first roller, the top surface of first ridge and first groove The distance between portion surface is substantially the same.

4. the equipment according to claim 1 or claim 2, wherein first roller includes transverse width, and wherein Around the circumference or the transverse width across first roller, the top surface of first ridge and the bottom of first groove The distance between portion surface changes.

5. the equipment according to claim 1 or claim 2, wherein the tooth for faceted and including at least four Or six sides.

6. the equipment according to claim 1 or claim 2, wherein the part that the tooth and ridge surface are intersected is finishing , to provide the geometry selected from truncation, half truncation, non-truncation and combinations thereof.

7. the equipment according to claim 1 or claim 2, wherein the top surface of first ridge is selected from radiant type , non-radiative formula or combinations thereof.

8. the equipment according to claim 1 or claim 2, wherein second roller is the ring roll with ridge, the ridge There is different height on described circumferential or axial direction.