Abstract:
A process of forming a soft and resilient web exhibiting a substantially continuous pattern of debossments or apertures is disclosed. The process comprises locally heating process to melt predetermined points of the web. The process includes: continuously bringing the web in contact relation with a forming structure exhibiting a substantially continuous pattern of apertures corresponding to the debossments or apertures of the web; locally heating the region of the web at the predetermined points along the surface of the web by an energy source to give the web temperature above its melting temperature; applying a substantially uniform fluid pressure differential to the locally heated web at least in those areas to be debossed or apertured, whereby the web is debossed or apertured at the predetermined points and generally maintains its surface structure at least in those areas in which the web is not debossed or apertured; and removing the debossed or apertured web from the forming structure. A soft and resilient web formed by the process is also disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a divisional of application Ser. No. 09/555,933 filed on Jun. 6, 2000, pending. 
     
    
     
       FIELD OF INVENTION  
         [0002]    The present invention relates to a process of forming a soft and resilient web and a soft and resilient web formed by the process. More particularly, the present invention relates to a process utilizing a locally heating process to form a soft and resilient web exhibiting a substantially continuous pattern of debossments or apertures. The present invention also relates to a soft and resilient web exhibiting a substantially continuous pattern of debossments or apertures.  
         BACKGROUND  
         [0003]    In processes disclosed in prior art for producing a web such as a formed film, a web of heat-softened film is provided on the patterned, perforated outer surface (referred to herein as a forming surface) of a structure such as an endless belt or a drum cylindrical surface. A vacuum beneath the forming surface pulls the heat-softened film into conformity with the forming surface. Alternatively, a positive pressure may be used to force the heat-softened film against the forming surface. Whether the web of film is simply embossed or is debossed and perforated will depend on the size of the holes in the forming surface, the softness and thickness of the film being formed, and the fluid pressure differential across the film.  
           [0004]    Processes for producing webs of embossed thermoplastic film are disclosed in U.S. Pat. Nos. Re 23,910 issued to Smith &amp; Smith on Dec. 12, 1954; 2,776,451 and 2,776,452 both issued to Chavannes on Jan. 8, 1957; and 2,905,969 issued to Gilbert &amp; Prendergast on Sep. 29, 1959. Processes for the production of webs of debossed and perforated thermoplastic films are disclosed in U.S. Pat. Nos. 3,038,198 issued to Shaar on Jun. 12, 1962; 3,054,148 issued to Zimmerli on Sep. 18, 1962; 4,151,240 issued to Lucas &amp; Van Coney on Apr. 24, 1979; 4,155,693 issued to Raley on May 22, 1979; 4,226,828 issued to Hall on Oct. 7, 1980; 4,259,286 issued to Lewis, Sorensen &amp; Ballard on Mar. 31, 1981; 4,280,978 issued to Dannheim &amp; McNaboe on Jul. 28, 1981; 4,317,792 issued to Raley &amp; Adams on Mar. 2, 1982; 4,342,314 issued to Radel &amp; Thompson on Aug. 3, 1982; and 4,395,215 issued to Bishop on Jul. 26, 1983. A process for the production of perforated seamless tubular film is disclosed in U.S. Pat No. 4,303,609 issued to Hureau, Hureu &amp; Gaillard on Dec. 1, 1981.  
           [0005]    The processes disclosed in the references cited above require that the thermoplastic film be heat-softened in order to achieve the desired embossing or debossing and perforation of the film. This can be achieved as disclosed in many of the above references by heating an existing web of film to a temperature above its melt temperature range such that it is in a molten state and will readily flow and attain a new configuration. Alternatively, the molten film may be achieved by feeding a web of film directly from a film extruder onto the forming surface. Such a process is disclosed in U.S. Pat. No. 3,685,930 issued to Davis &amp; Elliot on Aug. 22, 1972, where a web of thermoplastic film is extruded directly onto the outer surface of an endless belt and a vacuum is pulled beneath the belt to make the molten web of film assume the configuration of the outer belt surface. Similarly, U.S. Pat. No. 3,709,647 issued to Barnhart on Jan. 9, 1973 discloses a web of molten thermoplastic film extruded directly onto the outer cylindrical surface of a vacuum forming drum.  
           [0006]    It is known to shape molten thermoplastic sheet material by the use of a fluid pressure forcing the sheet against a mold; such processes are disclosed in U.S. Pat. Nos. 2,123,552 issued to Helwig on Jul. 12, 1938; and 3,084,389 issued to Doyle on Apr. 9, 1963.  
           [0007]    When webs of embossed or debossed and perforated thermoplastic film are produced on a patterned surface by the above prior art processes, it is generally necessary to cool the film below its melting temperature range to set its three-dimensional structure prior to removing the web of formed film from the forming surface. This makes the web of formed film much less susceptible to distortion of its bulk conformation.  
           [0008]    To make webs of formed film by these prior art processes, it is necessary to have the film within or above its melting temperature range in order to form the film. This limits the range of desired properties that can be engineered into the formed film since all previous thermo-mechanical history of the film is erased.  
           [0009]    Other attempts to produce a web, such as a formed film, are to apply a liquid pressure to the web on the forming surface. The liquid pressure has sufficient force and mass flux to cause the web to be deformed toward the forming surface such that the material acquires a substantial three-dimensional conformation. The temperature of the web of material is controlled such that it remains below the transformation temperature range of the material throughout the process. Such process is disclosed in U.S. Pat. No. 4,695,422 issued to Curro et al. on Sep. 22, 1987.  
           [0010]    In the process disclosed in the reference, the web is exposed to the liquid pressure, however, the temperature is below the transformation temperature range of the material which does not melt the material. When the material deforms by the liquid pressure, the material substantially ruptures and the some “spring-back” of the material generally occurs after it passes the zone of liquid pressure. This “spring-back” of the material causes dimensionally unstable, three-dimensional apertures on the web which results in poor resiliency of the web.  
           [0011]    Therefore, it is an objective of the present invention to provide a process of forming a soft and resilient web utilizing a locally heating process to form a substantially continuous pattern of debossments or apertures on the web.  
           [0012]    It is a further objective of the present invention to provide a soft and resilient web formed by the process utilizing a locally heating process to form a substantially continuous pattern of debossments or apertures on the web.  
         SUMMARY  
         [0013]    The present invention provides a process of forming a soft and resilient web exhibiting a substantially continuous pattern of debossments or apertures being formed by locally heated at predetermined points along the surface of the web. The process comprises: continuously bringing the web in contact relation with a forming structure exhibiting a substantially continuous pattern of apertures corresponding to the debossments or apertures of the web, the continuous pattern of the apertures extending from the outermost to the innermost surface of the forming structure; locally heating the region of the web at the predetermined points along the surface of the web by an energy source, the energy source heating the region of the web above its melting temperature range; applying a substantially uniform fluid pressure differential to the locally heated web at least in those regions to be debossed or apertured while the web is in contact with the forming structure, whereby the web is debossed or apertured at the predetermined points and generally maintains its surface structure at least in those areas in which the web is not debossed or apertured; and removing the debossed or apertured web from the forming structure.  
           [0014]    The present invention also provides a soft and resilient web exhibiting a substantially continuous three-dimensional pattern of macro-apertures. The web comprises a fluid impermeable plastic material. The web has a first surface, a second surface, a multiplicity of micro-apertures and a multiplicity of macro-apertures. The web has a land area on the first surface and a wall protruding beyond the second surface of the land area. The land area includes a pattern of fine-scale, volcano-like micro-apertures comprising discrete volcano-like surface aberrations and micro-openings. The aberrations protrude from the land area beyond the first surface of the land area. The micro-opening locates at the top of each aberration. The macro-apertures are defined by the wall, an opening on the first surface surrounded by the wall and an apex opening. The wall has the micro-apertures thereon. The size of the micro-apertures on the wall is generally smaller than that of the micro-apertures on the land area.  
           [0015]    The present invention further provides a soft and resilient web exhibiting a substantially continuous three-dimensional pattern of macro-apertures. The web comprises a fluid impermeable plastic material. The web has a first surface, a second surface, a multiplicity of micro-apertures and a multiplicity of macro-apertures. The web has a land area on the first surface and a wall protruding beyond the second surface of the land area. The land area includes a pattern of fine-scale, volcano-like micro-apertures comprising discrete volcano-like surface aberrations and micro-openings. The aberrations protrude from the land area beyond the first surface of the land area. The micro-opening locates at the top of the aberration. The macro-apertures are defined by the wall, an opening on the first surface surrounded by the wall and an apex opening. The wall has the micro-apertures thereon. The number of the micro-apertures on the wall is less than the number of the micro-apertures on the land area, per a unit area.  
           [0016]    The present invention further provides a soft and resilient web exhibiting a substantially continuous three-dimensional pattern of apertures. The web comprises fiber aggregation. The web has a first surface, a second surface, and a multiplicity of apertures. The web has a land area on the first surface and a wall protruding beyond the second surface of the land area. The apertures are defined by the wall, an opening on the first surface surrounded by the wall and an apex opening. The land area on the first surface comprises the fiber aggregation. At least a portion of the wall comprises the fiber aggregation, and at least a portion of the fiber aggregation is melted to each other at least adjacent the apex opening of the apertures. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be better understood from the following description in conjunction with the accompanying drawings, in which like reference numbers identify like elements, and wherein:  
         [0018]    [0018]FIG. 1 is a simplified schematic view of a web forming process of the present invention including two phase process;  
         [0019]    [0019]FIG. 2 is an enlarged fragmentary perspective view of the first forming structure utilized to support the web when the web is subjected to a first phase shown in FIG. 1;  
         [0020]    [0020]FIG. 3 is an enlarged cross-sectional view of the web which is supported on the surface of the first forming structure of the first phase shown in FIG. 1 when the web is subjected to a fluid pressure differential and a locally heating energy;  
         [0021]    [0021]FIG. 4 is an enlarged inset of the web after it has been removed from the first forming structure of the first phase shown in FIG. 1;  
         [0022]    [0022]FIG. 5 is an enlarged fragmentary perspective view of the second forming structure utilized to support the web when the web is subjected to a second phase shown in FIG. 1;  
         [0023]    [0023]FIG. 6 is an enlarged cross-sectional view of the web which is supported on the surface of the second forming structure of the second phase shown in FIG. 1 when the web is subjected to a fluid pressure differential and a locally heating energy;  
         [0024]    [0024]FIG. 7 is an enlarged cross-sectional view of the alternative embodiment of the forming structure;  
         [0025]    [0025]FIG. 8 is an enlarged cross-sectional view of the alternative embodiment of the forming structure;  
         [0026]    [0026]FIG. 9 is a simplified schematic view of the alternative embodiment which may be utilized for a part of the two phase process shown in FIG. 1;  
         [0027]    [0027]FIG. 10 is an enlarged cross-sectional view of the web which is supported on the surface of the forming structure of the alternative embodiment shown in FIG. 9 when the web is subjected to a fluid pressure differential and a locally heating energy;  
         [0028]    [0028]FIG. 11 is an enlarged fragmentary perspective view of a plastic film after completion of the web forming process;  
         [0029]    [0029]FIG. 12 is an enlarged cross-sectional view of the plastic film after completion of the web forming process;  
         [0030]    [0030]FIG. 13 is a greatly enlarged fragmentary perspective view of the plastic film after completion of the web forming process;  
         [0031]    [0031]FIG. 14 is an enlarged fragmentary perspective view of a web comprising fiber aggregation after completion of the web forming process;  
         [0032]    [0032]FIG. 15 is an enlarged cross-sectional view of the web comprising fiber aggregation after completion of the web forming process; and  
         [0033]    [0033]FIG. 16 is an enlarged cross-sectional view of a web comprising fiber aggregation and a plastic film after completion of the web forming process. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    While the present invention will be described in the context of providing three dimensional, apertured webs particularly suited for use as a wearer contacting surface on absorbent bandages such as disposable diapers, sanitary napkins, wound dressings and the like, the present invention is in no way limited to such applications. The patterns created may be of any desired shape, they may be regulated or random, reticulated or non-reticulated, continuous or interrupted, or any desired combination thereof. The detailed description of the structures disclosed herein and their suggested use as topsheets and/or backsheets in a disposable absorbent bandage context will allow one skilled in the art to readily adapt the invention to produce webs well suited to other applications.  
         [0035]    A particularly preferred multi-phase, continuous forming process of the present invention is schematically illustrated in FIG. 1. In the embodiment shown in FIG. 1, a substantially planar web  10  which may be comprised of, e.g., a thermoplastic film, a fiber aggregation, or a combination of a fiber aggregation and a thermoplastic film is fed from a supply roll  1  onto the surface of a first forming drum  18  about which a forming structure  15  continuously rotates at substantially the same speed as the incoming web. The forming drum  18  preferably includes an internally located vacuum chamber  20  and an energy source  21  such as a radiant energy source which is preferably stationary relative to the moving forming structure  15 . The forming drum  18  may further include a reflector  23 . An air jet means  22  is also provided adjacent the outside surface of the forming structure  15  opposite the vacuum chamber  20 .  
         [0036]    Forming structure  15 , a greatly enlarged fragmentary segment of which is illustrated in FIG. 2, includes a multiplicity of relatively small apertures  16  across all or any desired portion of its surface. For disposable absorbent article topsheet applications these apertures typically range in size between about 0.05 mm and about 0.5 mm in diameter. Their spacing may be in a regular pattern or it may vary randomly, as desired, in the resultant plastic film  10 . Methods for constructing suitable three-dimensional tubular forming members of this general type are disclosed in commonly assigned U.S. Pat. No. 4,503,256 issued to Radel et al. On Apr. 2, 1985 and commonly assigned U.S. Pat. No. 4,509,908 issued to Mullane, Jr. on Apr. 9, 1985, said patents being hereby incorporate herein by reference.  
         [0037]    The apertures  16  in the forming structure  15  may be of any desired shape or cross-section when the forming structure is fabricated utilizing the laminar construction techniques generally disclosed in the aforementioned commonly assigned patents. Alternatively, the tubular shaped forming structure  15  may be comprised of non-laminar construction and the desired pattern of apertures  16  created by means of laser drilling or the like. It is also possible to use belts or the like comprised of pliable material and operating continuously about a pair of rolls. In the latter circumstance, it is generally desirable to provide suitable support beneath the pliable belt while it is subjected to the fluid pressure differential in order to avoid distortion.  
         [0038]    It is preferable that the physical characteristics of the incoming web be substantially maintained in the regions of the web that overlay the area of the forming structure that are not aligned with the apertures  16 . This is, at least in part achieved by ensuring that the outer surface of the forming structure  15  is not heated to the temperature above the melting temperature of the incoming web. This may be achieved by coating the inside surface  15 A of the forming structure  15  with a reflective material  19  to reflect the radiant energy  21  A generated by the energy source  21  as shown in FIG. 3. The aperture walls  16 A may also be coated with this reflective material. The reflective material  19  may, for example be nickel plating or any other coating that effectively adheres to the inside surface  15 A while substantially reflecting the type of energy being used as a source. Alternately, the inside surface  15 A and/or the wall  16 A may be laminated using a reflective material. It is preferable to select appropriate reflective coatings based on their absorbency to the frequency spectrum of the energy source. To minimize conductive heat transfer from the inside surface ISA to the outside surface  15 B, layers of the forming structure  15  can be constructed of low thermal conductivity materials such as ceramics or high service temperature plastics. A semi-continuous layer internal to the forming structure  15  may be used to create interior voids further reducing thermal conduction to the outer surface  15 B. Other approaches to reduce conductive heat transfer to the web may include texturing of the outer surface of the forming structure  15 B to minimize physical contact with the web. Additionally, the forming structure  15  may be precooled as it rotates in order to further reduce the peak temperature that the outer surface  15 B reaches during the forming process. This may take the form of an airjet of cool air incident on the forming structure  15  immediately upstream of the location where the plastic film  10  is introduced. Alternatively, an additional vacuum plenum may be added internally to the forming structure  15  in a similar location to the above example to draw air through the forming structure thus cooling it prior to introduction of the plastic film  10 .  
         [0039]    The energy source  21  generates the radiant energy  21 A and the radiant energy source  21 A melts at least a part of the plastic web  10 . The radiant energy  21 A reaches the part of the plastic film  10  which is supported on the surface of the forming structure  15  through the apertures  16  of the forming structure  15 . The radiant energy  21 A heats a part of the plastic film  10  to a temperature above its melting temperature range such that a part of the plastic film  10  is in a molten and/or flowable state. The energy source  21  may take the form of a substantially targeted flux of electromagnetic radiation such as that provided by an infra-red radiant heater. This type of heater may be used to direct an electromagnetic energy flux towards a targeted area on the inside surface  15 A of the forming structure  15 . Radiant thermal heaters of this type are commercially available, emitting infra-red radiation at a predetermined and preferred wavelength. Further, these heaters can be equipped with variously shaped parabolic reflectors. The parabolic reflector serves to provide a concentrated parallel flux of radiant energy in a confined beam or, alternately, can target the energy flux at a predetermined focal point thus further intensifying the energy flux over this region. The energy flux incident on the plastic film  10  at the points co-incident with the apertures  16  must be sufficient to melt the plastic film  10  such that it can be induced to substantially conform to the apertures  16  by the fluid pressure differential. Although the above is one preferred embodiment of the energy source, the source can take many alternate forms. These may include lasers or other frequencies of electromagnetic radiation.  
         [0040]    It is desired that the temperature of the outside surface  15 B be maintained below the melting temperature of the plastic film  10  so as to maintain the physical structure of the incoming web in the areas not located above the apertures  16 . It is therefore preferable that the energy flux be targeted on a limited arc or region of the inside surface  15 A. This minimizes the opportunity for substantial thermal conduction to the outside surface  15 B, which would result in an undesirable increase in temperature for this surface. The energy flux should be of sufficient intensity so as to melt the plastic film  10  through the apertures  16  while permitting the duration of the energy incident on the inside surface  15 A to be minimized. It is known that the absorption co-efficient of polymers varies as a function of the frequency of the incident electromagnetic energy source. Therefore, the frequency of the energy source should typically be selected to maximize the energy absorbed by the plastic film  10 . At the same time, the reflective coating  15 A on the inner surface of the forming structure  15 , should be selected such that the maximum amount of energy incident on this surface  15 A is reflected. Appropriate selection and balancing of these two design parameters contributes to a robust process.  
         [0041]    A reflector  23  directs a part of the radiant energy  2   1 A towards a desired region on the inner surface  15 A of the forming structure  15 . The reflector  23  preferably has a parabolic shape with an opening  24  which faces the inside surface  15 A of the forming structure  15  and extends along the length of the energy source  21 . The reflector  23  may focus the radiant energy  21 A onto a very narrow region on the inner surface  15 A of the forming structure  15  in a circumferential direction. It may focus the radiant energy  21 A into a predetermined area on the inner surface  15 A of the forming structure  15 . The reflector  23  may have any preferred cross-sectional profile, such as a parabola. The reflector  23  is preferably made of metal coated with a highly emissive material such as nickel so as to reflect the radiant energy  21 A very effectively. The reflector  23  may for example, be made by electroplating a pre-formed thin metal plate. Such reflectors are commercially available from suppliers such as OGDEN Mfg. Co. (USA) and are often an integral component of a radiant heater.  
         [0042]    A differential pressure is applied across the plastic film  10  between the air jet means  22  and inner chamber  20  and in the region along the circumference of the forming structure  15  where the plastic film  10  is locally melted. The air jet means  22  approximately coincides with the beginning and the end of the inner chamber  20  and is located adjacent the outside surface  15 B of the forming structure  15 . In this region, a substantially uniform fluid pressure differential is applied to the plastic film  10 . This may be applied by means of a positive pressure (high pressure) within the air jet means  22 , a partial vacuum (low pressure) within the chamber  20  or a combination of these two conditions. Thus, a substantial differential pressure is applied to the substantially planar web of the polymeric web  10  as it passes across the suction chamber. The high pressure air  22 A which is generated by the air jet means  22  may be preheated to a temperature below the softening temperature of the plastic film  10  to help to make more dimensionally stable micro-apertures  50 . Alternatively, the high pressure air  22 A may be precooled to help further maintain the thermo-mechanical history given to the plastic film  10  which is not located on the apertures  16  of the forming structure  15 . The high pressure air  22 A may be precooled to a temperature below the plastic film temperature before the plastic film  10  is provided on the forming structure  15 .  
         [0043]    As shown in FIG. 3, the forming structure  15  rotates in the direction D with the plastic film  10 . FIG. 3 shows four sequential apertures  16 B,  16 C,  16 D and  16 E of the forming structure  15  as it rotates in the downstream direction D. At the aperture  16 B at the upstream end, the energy source  21  gives the radiant energy  21 A to the plastic film  10  from the inside of the forming structure  15  through the aperture  16 B to soften the plastic film  10 . Since there is an inward pressure differential  22 A applied in this region, the softened plastic film  10  is deformed slightly inward. While the forming structure  15  rotates toward the position of the aperture  16 C shown in FIG. 3, the plastic film  10  receives more radiant energy  21 A and the softened plastic film  10  deforms further into the aperture  16 . As the forming structure  15  further rotates, the softened plastic film  10  locally melts, rupturing and debossing as shown at the position of the aperture  16 D making the aperture  50  in the plastic film  10 . While the forming structure  15  continues to rotate from the position of the aperture  16 D to  16 E, the plastic film  10  receives more radiant energy  21 A and high air pressure  22 A flowing through the newly formed film aperture  50 . This causes the plastic film  10  to further conform to the shape of the aperture  16  of the forming structure  15  and the aperture  50  to become more stable to form a fine-scale, three-dimensional, volcano-like micro-aperture  50 . During the process, regions of the polymeric film  10  not located above the apertures  16  of the forming structure  15  are not heated beyond the melting temperature range of the resin. Therefore, the thermo-mechanical history previously existing in the film is maintained in these regions.  
         [0044]    After the plastic film  10  is apertured, the finely apertured plastic film  10  is removed from the surface of the first fine-scale forming structure  15  about an idler roll  39  in the condition illustrated in greatly enlarged form in the inset of FIG. 4. Because the plastic film  10  is molten only at a portion over the apertures  16  of the forming structure  15  during the forming process, it can be more easily removed from the forming structure  15  requiring only a shorter time period for cooling the plastic film  10 . This has the further advantage of permitting increased processing speeds and web stability and/or a broader range of plastic webs that would otherwise lack stability in alternate processes. This further increases the flexibility to obtain finished webs of greater wearer acceptance by using, for example, incoming webs of lower basis weight or lower density resins to increase flexibility and thus softness of the micro-apertures.  
         [0045]    Because of the presence of the fine-scale, three-dimensional, volcano-like micro-apertures  50  and fine cusps  53 , the first surface  57  which contacted forming structure  15  exhibits a much softer tactile impression than the second surface  54  which was contacted by the high pressure air  22 A. Accordingly, the first surface  57  of the plastic film  10  is generally preferred as the wearer contacting surface over the second surface  54 .  
         [0046]    As will be appreciated by those skilled in the art, the degree of conformance of the plastic web  10  to the surface of the forming structure  15  and the size of the apertures created therein will be influenced by factors such as the temperature of the film  10  at the time it is subjected to the high pressure air  22 A, the pressure at which the air jet means  22  is applied to the surface of the film, the temperature of the air, the mass flux of the air, etc. More importantly, the degree of conformance and the size of the apertures may be influenced by the type of radiant energy, intensity of radiant energy, flux of radiant energy, etc. In general, when the fluid pressure differential is applied to the web, the lower the viscosity of the plastic film  10  being locally heated, the greater will be the degree of conformance and aperturing. In addition, the less the temperature of the plastic film  10  in the regions not located above the apertures  16  is altered from its original state, the less the thermo-mechanical history is altered.  
         [0047]    After completion of the first phase of the web forming process disclosed in FIG. 1, the finely apertured plastic film  10  may be fed to the second phase of the forming process for macroscopic expansion or to a rewind station for temporary storage. In the latter circumstance, application of the second phase of the process may be deferred until a later date, perhaps at a different location. Alternatively, the finely apertured plastic film  10  may be utilized without further processing in an end product wherein fluid permeability and a soft tactile impression are particularly desirable, but a macroscopically expanded, three-dimensional cross-section is not essential.  
         [0048]    Because of the desirable tactile impression imparted to the first surface  57  of the plastic film  10  in the embodiment illustrated in FIG. 1, the plastic film  10  which is to undergo macroscopic, three-dimensional expansion is preferably fed onto a second forming structure  35  which operates about forming drum  38  so that its opposite second surface  54  is placed in contact with the second forming structure  35 . The forming drum  38 , which may be generally similar to the forming drum  18  includes a stationary vacuum chamber  40  located adjacent the interior of the forming structure  35  and an energy source  41 , both of which may be generally similar structure to the chamber  20  and the energy source  21  respectively. The forming drum  38  may further include a reflector  43 , which also may be generally similar to the reflector  23 . An air jet means  42  is also provided adjacent the outside surface of the forming structure  35  opposite the vacuum chamber  40 . Because the macroscopic cross-section of forming structure  35  is considerably different than that of forming structure  15 , the pressure and mass flux rates of the air jet means  42  are preferably adjusted independently of the pressure and mass flux rates used for the air jet means  22 . The radiant energy generated by the energy source  41  is also preferably adjusted independently of the radiant energy of the radiant energy source  21 .  
         [0049]    The macroscopic cross-section of forming structure  35  is visible in the greatly enlarged fragmentary perspective of FIG. 5. The forming structure  35  exhibits a substantially continuous three-dimensional pattern including a multiplicity of apertures  36 . Although not limited to these dimensions, for disposable absorbent article topsheet applications, these macro-apertures typically range in size from 0.3 to 3.0 mm and are typically at least 4 times as big as the fine-scale small apertures  16  of the forming structure  15 . The forming structure  35  has the outside surface  35 B and the inside surface  35 A. The forming structure  35  may comprise a plurality of layers. In the embodiment shown in FIG. 5, the forming structure  35  includes three layers L1, L2 and L3. Each of the layers may have a different thermal conductivity from layer to layer in order to minimize heat transfer to the plastic film  10  supported on the outer surfaces  35 B. This is so that the outer surface of the forming structure  35 B is not heated above the melting temperature range of the plastic film  10 . Alternatively, the inside surface  35 A of the forming structure  35  may be coated with a reflective material in order to reflect the radiant energy generated by the energy source  41 . The wall of the apertures  36 A also may be coated by the reflective material or laminated with the reflective material. As shown in FIG. 6, the wall of the apertures  36 A may be generally at a right angle to the outside surface  35 B and the inside surface  35 A. Alternatively, the wall  36 A of the apertures  36  may be angled relative to the inner surface such that the size of the apertures  36  becomes smaller from the outside surface  35 B towards the inside surface  35 A as shown in FIG. 7. Alternatively, the wall  36 A of the apertures  36  may be angled relative to the inner surface such that the size of the apertures  36  becomes larger from the outside surface  35 B towards the inside surface  35 A as shown in FIG. 8.  
         [0050]    As is more readily apparent from the inset of FIG. 6, the plastic film  10  containing the fine-scale, volcano-like micro-apertures  50  is fed onto the outside surface  35 B of the forming structure  35  such that its second surface  54  contacts the forming structure  35 , while its first surface  57  is oriented toward the air jet means  42 . Accordingly, the small cusps  53  of the micro-apertures  50  are oriented toward the air jet means  42 .  
         [0051]    The regions of the plastic film  10  with the fine-scale, volcano-like micro-apertures  50 , which are located above the apertures  36  of the forming structure  35 , receive the radiant energy  41 A generated by the energy source  41 . Thereby, the regions of the plastic film  10  receiving the radiant energy  41 A are locally heated above the film softening temperature. The region of the plastic film  10  locally heated is also exposed to high pressure air  42 A and deforms toward the inside of the forming structure  35 . As the forming structure  35  rotates, the region of the plastic film  10  receives more radiant energy  41 A and high pressure air  42 A. The region of the plastic film  10  further deforms into the aperture  36  and finally ruptures to form the macro-apertures  60  surrounded by a wall  61  on the plastic film  10 . As the forming structure  35  rotates further, the region of the plastic film  10  further melts, and the plastic film  10  substantially conforms to the shape of the apertures  36 . Since the plastic film  10  is melted and conforms to the shape of the apertures  36 , the shape of the macro-apertures  60  corresponding to the apertures  36  become substantially regular and thus the plastic film  10  with the dimensionally stable macro-apertures  60  becomes substantially dimensionally stable and resilient. During this process, because a region of the wall  61  of the plastic film  10  melts, the fine scale, volcano-like micro-apertures  50  on the wall  61  tend to disappear such that the wall  61  of the plastic film  10  conforms to the apertures  36  of the forming structure  35  and is substantially without micro-apertures. On the other hand, the region of the plastic film  10  which contacts the outside surface  35 B of the forming structure  35  does not receive the radiant energy  41 A, the forming structure  35  also being constructed so as to minimize heat transfer to these portions of the plastic film  10 . The high pressure air  42 A also does not change the surface structure of the plastic film  10 . Therefore, the fine-scale volcano-like micro-apertures  50  which are oriented toward the air jet means  42  do not disappear and remain on the surface of the plastic film  10 .  
         [0052]    After completion of the second phase the macroscopically expanded, three-dimensional, apertured plastic web  10  is removed from the forming structure  35  and wrapped about idler rolls  110  and  120  from where it may be fed either to a rewinding station for temporary storage or directly to converting lines where it may be applied to making finished product structures, such as disposable absorbent articles.  
         [0053]    In the above multi-phase forming process, the first phase may comprise any conventional process which forms apertures on incoming web, such as a process using a liquid pressure differential across the web or a process using an air pressure differential across the web while the entire web is in the molten state. The first phase may be directly coupled to the second phase to form an integral multi-phase process, or may be conducted separately and a roll of material unwound into the second phase described above for final forming.  
         [0054]    [0054]FIGS. 9 and 10 show alternative embodiment of a forming process of the present invention which may be used for either or both of the first or second phases in the above two-phase forming process. The alternative shown in FIGS. 9 and 10 is suitable especially for the second process. In the embodiment shown in FIG. 9, the plastic film  10  may be fed onto the surface of a forming drum  100  about which a forming structure  101  continuously rotates at substantially the same speed as the incoming web  10 . The forming drum  100 , which may be generally similar to the forming drum  38 , may include a stationary vacuum chamber  102 , which may be generally similar structure to the chamber  40 , located adjacent the interior of the forming structure  101 . An energy source  103  with a reflector  104  may be disposed outside the forming structure  101 . The energy source  103  may be covered by a shield screen  105  with a pattern of apertures and air jet means  106  may be provided adjacent the outside surface of the forming structure  101 .  
         [0055]    The forming structure  101  has a pattern of apertures  110  which may be generally similar to the pattern of the apertures  36  on the forming structure  35 . The shield screen  105  which has a cylindrical shape rotates at substantially the same speed as the forming structure  101 . The shield screen  105  may have a pattern of apertures  111  on the surface generally identical to the pattern of the apertures  110  on the forming structure  101 . As the shield screen  105  rotates with the forming structure  101 , each of the apertures  111  on the shield screen  105  and each of the apertures  110  on the forming structure  101  correspond to each other as shown in FIG. 10. The shield screen  105  comprises a material which reflects at least a part of the radiant energy  103 A generated by the energy source  103 . Alternatively, at least the inside  105 A of the shield screen  105  may be coated by the reflective material or laminated with the reflective material. The energy source  103  provides radiant energy  103 A to the region of the plastic film  10  through the aperture  111  from the inside of the shield screen  105  such that the region of the plastic film  10  is locally heated. As the region of the plastic film  10  receives more radiant energy  103 A, the region of the plastic film  10  softens and melts. The air jet means  106  applies high pressure air  106 A to the plastic film  10  and/or the vacuum chamber  102  draws air to pull the softened region of the plastic film  10 . Thereby, a fluid pressure differential is provided across the plastic film  10  by a pressure gradient from the air jet means  106  toward the vacuum chamber  102 . While the energy source  103  locally heats and melts the region of the plastic film  10  which corresponds to the apertures  111  of the shield screen  105 , the shield screen  105  prevents the region of the plastic film  10 , which is shielded from the radiant energy  103 A, from being substantially heated, thereby retaining its original form. After completion of the process, the plastic web  10  is removed from the forming structure  101  and may be forwarded down stream. The high pressure air  106  may be pre-heated or pre-cooled in order to further stabilize the process as previously described.  
         [0056]    FIGS.  11 - 13  show the fully processed plastic film  10 . The plastic film  10  shown in FIGS.  11 - 13  may be used for a body-facing material for an absorbent article. As will be apparent from the enlarged fragmentary perspective view of the plastic film  10  shown in FIG. 11, the fully processed plastic film  10  exhibits dimensionally stable, three-dimensional macro-apertures  60  and fine-scale, volcano-like micro-apertures  50 . The plastic film  10  has a first surface  57  and a second surface  54 . The plastic film  10  has a land area  56  which faces the wearer&#39;s body when the plastic film  10  is used as a topsheet of an absorbent article. The plastic film  10  also has volcano-like aberrations  58 .  
         [0057]    The land area  56  has a pattern of fine scale, volcano-like surface micro-apertures  50 . The fine scale, volcano-like micro-apertures  50  comprise the volcano-like aberrations  58  and the micro-opening  62  at the top of the aberrations  58 . The size of the micro-apertures  50  on the land area  56  may be defined by either of the average height of the aberrations  58  or the average area of the micro-openings  62  or by both of these. The micro-openings  62  on the land area  56  have an average aperture area which typically may be from 0.002 mm 2  and 0.2 mm 2 . The aberrations  58  on the land area  56  protrude from the land area  56  beyond the first surface  57  of the land area  56 . The aberrations  58  have an average height which typically may be from 0.05 mm and 0.5 mm. Each of the fine-scale, volcano-like micro-apertures  50  actually forms a small capillary network resembling a tiny volcano, the outermost edges of which end in silky and soft feeling cusps  53 . Due to the tactile impression imparted to the plastic film  10  by cusps  53 , the land area  56  of the plastic film  10  is normally perceived as well suited for sustained contact with the skin. As explained in the above process description, the fine-scale, volcano-like micro-apertures  50  are maintained on the first surface  57  generally without changing its shape.  
         [0058]    The macro-apertures  60  are defined by the wall  61 , an opening  60 A located on the first surface  57  and the apex opening  60 B. The size of the macro-apertures  60  is generally bigger than the size of the fine-scale, volcano-like micro-apertures  50  located on the land area  56 . Preferably, the size of the macro-apertures  60  may be at least b  4  times as big as the size of the micro-apertures  50 . The wall  61  extends and protrudes beyond the second surface  54  of the land area  56 . The wall  61  may have the fine-scale, volcano-like micro-apertures  50  on its surface. The fine-scale, volcano-like micro-apertures  50  on the wall  61  may also comprise the volcano-like aberrations  58  and the micro-opening  62  at the top of the aberrations  58 . The size of the micro-apertures  50  on the wall  61  may be defined by either of the average height of the aberrations  58  or the average area of the micro-openings  62  or by both of these. The size of micro-apertures  50  on the wall  61  is generally smaller than that of the micro-apertures on the land area  56 . As shown in FIGS. 12 and 13, both the height of the aberrations  58  and the aperture area of the micro-openings  62  are generally decreasing toward the apex opening  60 B because the wall  61  of the plastic film  10  is heated and melted during the process as described above. While the micro-apertures  50  on the wall  61  shown in FIGS. 12 and 13 loses both the height and the area of the micro-apertures  50 , they may maintain either of these. The micro-apertures  50  on the wall  61  may lose only its height of the aberrations  58 . Alternatively, the micro-apertures  50  on the wall  61  may lose only its aperture area of the micro-openings  62 . Consequently, the wall  61  becomes dimensionally stable and becomes stiffer than the land area  56  which has many micro-apertures  50  thereon. The wall  61  also becomes more resilient to be capable of withstanding and rebounding from a pressure which is given by the wearer when the plastic film  10  is used for an absorbent article topsheet. Further, losing the height of the volcano-like aberrations  58  and the area of the micro-openings  62 , the wall  61  may have no micro-apertures at the region adjacent the apex opening  60 B, or most or all region of the wall  61 . Therefore, the number of the micro-apertures  50  per a unit area may be less on the wall  61  than the land area  56 . In the embodiment shown in FIG. 13, although there is still aberrations adjacent the apex opening  60 B, the aberrations  58 A have lost the micro-opening on the top of the aberrations.  
         [0059]    When the plastic film  10  is used for the absorbent article topsheet, the plastic film  10  shown in FIGS.  11 - 13  gives softer tactile impression to the wearer because the plastic film  10  has the fine-scale, volcano-like micro-apertures  50  with the cusps  53  on the land area  56 . The plastic film  10  also shows good fluid acquisition because the macro-apertures  60  have a dimensionally stable shape of apertures which makes fluid penetrate easily. In addition, the plastic film  10  shows good rewet performance because the wall  61  of the macro-apertures has resiliency so that the wearer&#39;s skin is maintained at a distance away from an absorbent core which absorbs body fluid by interposing the resilient plastic film  10  therebetween.  
         [0060]    FIGS.  14 - 15  show alternative embodiment of the fully processed web  150  comprising fiber aggregation  152 . The fibrous web  150  can be made from a fiber aggregation  152  which is formed as a nonwoven. The nonwoven may be processed only by the second process shown in FIG. 1 since the fibrous web  150  may not have micro-apertures on the land area. However, if desired, the nonwoven may be processed by both the first process and the second process shown in FIG. 1. Alternatively, a nonwoven may be processed by the process shown in FIG. 9 in order to get the processed fibrous web  150 .  
         [0061]    The fully processed fibrous web  150  exhibits dimensionally stable, three-dimensional macro-apertures  154 . The fibrous web  150  may be used for a body-facing material for an absorbent article. The fibrous web  150  has a first surface  156  and a second surface  158 . The fibrous web  150  has a land area  160  which upwardly faces the wearer&#39;s body when the fibrous web  150  is used as a topsheet of an absorbent article and a wall  162  which protrudes beyond the second surface  158  of the land area  160 . The macro-apertures  154  are defined by the wall  162 , an opening  164  on the first surface surrounded by the wall  162  and an apex opening  166 .  
         [0062]    The fibrous web  150  comprises fiber aggregation  152  which may include one fibrous layer or more layers. Each layer may comprise any type of thermoplastic fibers using such as polyethylene, polypropylene, polyester or any combination thereof. The thermoplastic fibers may be bi-component fibers using the above materials. The thermoplastic fibers may be of varying the cross-section. When the fiber aggregation  152  includes at least two layers having the first layer which is disposed adjacent the first surface  156  and the second layer which is disposed adjacent the second surface  158 , each layer may comprise different types of thermoplastic fibers from each other. Further each layer may comprise different types of forming processes from each other, such as spunbond, carded or meltblown layers. Alternatively, they may comprise the same type of fibers. Optionally, the first layer disposed adjacent the first surface  156  may comprise less hydrophilic fibers than the second layer disposed adjacent the second surface  158  whereby the first layer becomes less hydrophilic than the second layer.  
         [0063]    The land area  160  of the fibrous web  150  comprises fiber aggregation  152  and exhibits capillary network therein. The land area  160  of the fibrous web  150  gives soft tactile impression to the wearer and a soft feeling when the land area  160  touches the wearer&#39;s body.  
         [0064]    A portion of the wall  162 -also comprises the fiber aggregation  152 . At least a portion of the fibers forming the wall  162  are melted and bonded to each other by, e.g., the above process whereby the fiber aggregation  152  on the wall  162  is densified at least at a portion. Preferably the fiber aggregation  152  may be melted and densified at least at a portion adjacent to the apex opening  166 . Thereby the fiber aggregation  152  on the wall  162  may have a positive fiber density gradient from the opening  164  toward the apex opening  166  as schematically shown in FIGS. 14 and 15. Alternatively, most or all of the fiber aggregation  152  of the wall  162  may be melted and densified. The melted and densified fiber aggregation  152  becomes stiffer than the other portion of the fiber aggregation  152 , such as the fiber aggregation  152  on the land area  160 . The stiff wall also has more resiliency. Therefore, the wall  162  is capable of withstanding and/or rebounding from pressure given by the wearer when the fibrous web  150  is used as a topsheet of an absorbent article.  
         [0065]    When the fibrous web  150  is used for the absorbent article topsheet, the fibrous web  150  shown in FIGS. 14 and 15 gives soft tactile impression to the wearer because the fibrous web  10  comprises the fiber aggregation  152  on the land area  160 . The fibrous web  150  also shows good fluid acquisition because the macro-apertures  154  has a dimensionally stable shape of apertures which makes fluid penetrate easily. In addition, the fibrous web  150  shows good rewet performance because the wall  162  of the macro-apertures has resiliency so that the wearer&#39;s skin is maintained at a distance away from an absorbent core which absorbs body fluid by interposing the resilient fibrous web  150  therebetween.  
         [0066]    [0066]FIG. 16 shows a further alternative embodiment of the fully processed composite web  180  comprising fiber aggregation  182  and a plastic film  183 . The composite web  180  can be made from a fiber aggregation  182  which is formed as a nonwoven and a plastic film  183 . The nonwoven and the plastic film may be processed only by the second process shown in FIG. 1 since the composite web  180  may not have micro-apertures on the land area. However, if desired, a nonwoven and a plastic film which form the composite web  180  may be processed by both the first process and the second process shown in FIG. 1. Alternatively, a nonwoven and a plastic film may be processed by the process shown in FIG. 9 in order to get the composite web  180 .  
         [0067]    The fully processed composite web  180  exhibits dimensionally stable, three-dimensional macro-apertures  184 . The composite web  180  may be used for a body-facing material for an absorbent article. The composite web  180  has a first surface  186  and a second surface  188 . The composite web  180  has a land area  190  which upwardly faces the wearer&#39;s body when the composite web  180  is used as a topsheet of an absorbent article and a wall  192  which protrudes beyond the second surface  188  of the land area  190 . The macro-apertures  184  are defined by the wall  192 , an opening  194  on the first surface surrounded by the wall and an apex opening  196 .  
         [0068]    The composite web  180 , may include fiber aggregation  182  which may have one fibrous layer or more layers. Each layer may comprise thermoplastic fibers which may be the same materials for the fiber aggregation  152  above. Further, the composite web  180  may include at least one thermoplastic film layer  183  which may comprise various materials, such as polyethylene, low density polyethylene, linear low density polyethylene, or polypropylene. Preferably, the materials for the fiber aggregation  182  and the thermoplastic film may comprise the chemically same or chemically similar type of materials such that the fiber aggregation  182  and the thermoplastic film  183  can be bonded when they are melted to each other. Preferably, the fiber aggregation  182  is disposed on the first surface  186  of the composite web  180  and the plastic film  183  is disposed on the second surface  188 . The fiber aggregation  182  may be less hydrophilic than the plastic film  183  so that the composite web  180  has positive hydrophilicity gradient from the fiber aggregation  182  towards the plastic film  183 .  
         [0069]    The land area  190  of the composite web  180  comprises the fiber aggregation  182  and the plastic film  183 , and exhibits capillary network therein. The fiber aggregation  182  on the first surface  186  of the land area  190  can be directly seen by the wearer, therefore gives soft tactile impression to wearer. The plastic film  183  on the second surface  188  of the land area  190  prevents body fluid, which is held in an absorbent core of an absorbent article, from leaking out toward the wearer&#39;s skin through the land area  190 . Further, the plastic film  183  also serves to mask the color of the body fluid held in the absorbent core.  
         [0070]    A portion of the wall  192  also comprises the fiber aggregation  182  and the plastic film  183 . At least a portion of the fiber aggregation  182  on the wall  192  is melted and bonded to each other by, e.g., the above process whereby the fiber aggregation  182  on the wall  162  is densified at least at a portion. Preferably the fiber aggregation  182  may be melted and densified at least at a portion adjacent the apex opening  196 . Thereby the fiber aggregation  182  on the wall  192  may have a positive fiber density gradient from the opening  194  toward the apex opening  196  as schematically shown in FIG. 16. Alternatively, most or all of the fiber aggregation  182  of the wall  192  may be melted and densified. Preferably, at least a portion of the fiber aggregation  182  on the wall  192  is melted and bonded to the plastic film  183 . The plastic film  183  also may be melted and bonded with the fibers of the fiber aggregation  182 . As schematically shown in FIG. 16, the fiber aggregation  182  and the plastic film  183  are melted to each other at least adjacent the apex opening  196 . If desired, the fiber aggregation  182  and the plastic film  183  may be melted and bonded to each other on most or all portion of the wall  192 . The melted and densified fiber aggregation  152  and the plastic film  183  which are bonded together become stiffer than the other portion of the fiber aggregation  152  and the plastic film  183 , such as on the land area  190 . The stiff wall also has more resiliency. Therefore, the wall  192  is capable of withstanding and/or rebounding from pressure given by the wearer when the fibrous web  180  is used as a topsheet of an absorbent article.  
         [0071]    When the composite web  180  is used for the absorbent article topsheet, the composite web  180  shown in FIG. 16 gives a soft impression to the wearer because of the fiber aggregation  182  on the land area  190 . The composite web  180  also shows good fluid acquisition because the macro-apertures  184  have a dimensionally stable shape of apertures which makes fluid penetrate easily. In addition, the composite web  180  shows good rewet performance because the wall  192  of the macro-apertures has resiliency so that the wearer&#39;s skin is maintained at a distance away from an absorbent core which absorbs body fluid by interposing the resilient composite web  180  therebetween. The composite web  180  also helps mask the color of body fluid which is held in the absorbent core.  
         [0072]    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.