Patent Document

RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 09/633,944 filed on Aug. 8, 2000, which is a division of U.S. application Ser. No. 09/292,256, filed on Apr. 15, 1999. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to automatic package forming, filling and sealing machines involving fasteners, for example, with complementary male and female profiles. Specifically, a package is formed by moving a length of thermoplastic film and attaching to the film sequentially and crosswise with reference to the direction of movement of the film, a fastener including a first strip supporting one reclosable profile engaged with another reclosable profile that is complementary thereto and supported by a second strip or a part of the first strip, which will subsequently be attached to the film.  
           [0004]    2. Description of the Prior Art  
           [0005]    U.S. Pat. No. 4,909,017 to McMahon et al. describes a process in which bags are provided with a fastener when they are formed on a forming, filling and sealing (FFS) machine. The bags are formed from a film of thermoplastic material. The film is in the form of a strip of material extending between two free edges that are longitudinal with reference to the movement of the film. This film is unrolled upstream of a filling tube. The fastener is positioned on the film, also upstream of the filling tube and transversely with respect to the direction of movement of the film. The fastener comprises two strips provided with complementary profiles. A first strip of the fastener is welded to the film upstream of the tube, on a portion of the film which is intended to form a first bag wall. The bag is then formed by enveloping the tube and welding the two longitudinal edges of the film. The second fastener is then welded below the tube to a second bag wall.  
           [0006]    U.S. Pat. No. 4,655,862 to Christoff et al. also describes a process for forming reclosable bags on FFS machines, in which bags are provided with a fastener positioned at right angles to the direction of formation of these bags. This fastener is placed below the filling tube on a film in the form of a single strip. This strip includes at least one fold zone crosswise to the strip so that the strip can be folded back on itself, and areas of the strip that can work together to seal the bag can be brought opposite one another.  
           [0007]    It is therefore an object of the present invention to make the steps involving the support, welding and installation of the fastener on the film easier to perform than in the processes described in the above-cited references.  
         SUMMARY OF THE INVENTION  
         [0008]    The above and other beneficial objects of the present invention are attained by providing a process for the fabrication of a film material intended to form the bags, including steps of moving the film and fixing fasteners sequentially on the film and transversely with reference to the direction of movement of the film. The fastener comprises a first strip supporting at least one reclosable profile in engagement with another reclosable profile, which is complementary thereto and is supported by a second strip or a part of the first strip. The second strip or the part of the first strip that supports the other profile will be subsequently fixed to the film. Each strip has at least one web extending laterally on one side of the profile or profiles supported thereby.  
           [0009]    These webs give the invention a number of advantages. Because of its larger cross-section, a fastener for implementing the process according to the invention is easily moved and positioned. In addition, the webs can be attached at sufficiently low temperatures to prevent damaging the profiles.  
           [0010]    It is also possible for the step of attaching the fastener to the film to be performed by sealing the film with at least one area of these webs different from the area located under the profiles to prevent damage to the profiles during the attaching step. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The above and other aspects, purposes and advantages of the invention will be apparent from the following detailed description. The invention will also be more fully understood when read in conjunction with the accompanying drawings, in which:  
         [0012]    [0012]FIG. 1A is a cross-sectional view of a first fastener for embodying the process according to the invention;  
         [0013]    [0013]FIG. 1B is a cross-sectional view of a second fastener for embodying the process according to the invention;  
         [0014]    [0014]FIG. 1C is a cross-sectional view of a third fastener for embodying the process according to the invention;  
         [0015]    [0015]FIG. 1D is a cross-sectional view of a fourth fastener for embodying the process according to the invention;  
         [0016]    [0016]FIG. 1E is a cross-sectional view of a fifth fastener for embodying the process according to the invention;  
         [0017]    [0017]FIG. 2 is a perspective view of a fastener and means for welding the fastener onto a film intended to form reclosable bags using the process according to the invention;  
         [0018]    [0018]FIG. 3 is a perspective view of first and second means for welding the fastener located upstream and downstream, respectively, of a filling tube of a bag forming machine according to the invention;  
         [0019]    [0019]FIG. 3A is a perspective view of a variant of the bag forming machine that is adapted for fixing fasteners which include a slider;  
         [0020]    [0020]FIG. 4 is a top plan view of the second welding means of the bag forming machine;  
         [0021]    [0021]FIG. 4A is a top plan view of the second welding means of the variant of a bag forming machine, which is adapted for attaching fasteners that include a slider;  
         [0022]    [0022]FIG. 5 is a cross-sectional view of the filling tube and the second welding means taken along line  5 - 5  of the bag forming machine shown in FIG. 4;  
         [0023]    [0023]FIG. 5A is a cross-sectional view of a variant of the second welding means taken along line  5 A- 5 A of the bag forming machine shown in FIG. 4A, with the second welding means adapted for attaching fasteners that include a slider;  
         [0024]    [0024]FIG. 6 is a cross-sectional view of an example of a fastener for embodying the process according to the invention;  
         [0025]    [0025]FIGS. 7A and 7B are cross-sectional views that are crosswise to the length of the fastener shown in FIG. 6, showing second welding means and means for cutting of the bag forming machine;  
         [0026]    [0026]FIG. 8 is a cross-sectional view of another example of a fastener for embodying the process according to the invention;  
         [0027]    [0027]FIG. 9A is a cross-sectional view of the second welding means and of the cutting means that is crosswise to the length of the fastener shown in FIG. 8;  
         [0028]    [0028]FIG. 9B is a view similar to FIG. 9A but after the welding operation is completed;  
         [0029]    [0029]FIG. 10 is a cross-sectional view of another example of the fastener;  
         [0030]    [0030]FIG. 11 is a cross-sectional view of still another example of the fastener;  
         [0031]    [0031]FIG. 12 is a top plan view of a reclosable bag provided with another example of the fastener;  
         [0032]    [0032]FIG. 13 is a cross-sectional view of another example of the fastener;  
         [0033]    [0033]FIG. 14 is a cross-sectional view of the fastener shown in FIG. 13 in a closed configuration;  
         [0034]    [0034]FIG. 15 is a cross-sectional view of another variant of the fastener;  
         [0035]    [0035]FIG. 16 is a cross-sectional view of the top of a reclosable bag that includes another variant of the fastener;  
         [0036]    [0036]FIG. 17 is a cross-sectional view of another variant of the fastener;  
         [0037]    [0037]FIG. 18 is a cross-sectional view of the fastener shown in FIG. 17 in the closed configuration;  
         [0038]    [0038]FIG. 19 is a cross-sectional view of another variant of the fastener;  
         [0039]    [0039]FIG. 20 is a cross-sectional view of the fastener shown in FIG. 19 in a closed configuration;  
         [0040]    [0040]FIG. 21 is a cross-sectional view of a variant of the attachment of a fastener on a film;  
         [0041]    [0041]FIG. 22 is a cross-sectional view of the top of a reclosable bag with a fastener attached to the bag according to a variant of the process according to the invention;  
         [0042]    [0042]FIG. 23 is a cross-sectional view of still another variant of the fastener;  
         [0043]    [0043]FIG. 24 is a top plan view of a tape of the fastener;  
         [0044]    [0044]FIG. 25 is a top plan view of a tamper-evident reclosable bag;  
         [0045]    [0045]FIG. 26 is a top plan view of the second welding means of the variant of a bag forming machine adapted for attaching fasteners that include a slider and a film extension adjacent the fastener;  
         [0046]    [0046]FIG. 27 is a cross-sectional view that is crosswise to the length of the fastener shown in FIG. 1D taken along line  27 - 27  of FIG. 26;  
         [0047]    [0047]FIG. 27A is a cross-sectional view that is crosswise to the length of the fastener shown in FIG. 1E taken along line  27 A- 27 A of FIG. 26;  
         [0048]    [0048]FIG. 27B is a cross-sectional view that is crosswise to the length of fastener shown in FIG. 1B taken along line  27 B- 27 B of FIG. 26;  
         [0049]    [0049]FIG. 27C is a cross-sectional view that is crosswise to the length of fastener, with the fastener being a combination of the fasteners shown in FIGS. 1B and 11, the view taken along line  27 C- 27 C of FIG. 26; and  
         [0050]    [0050]FIG. 27D is a cross-sectional view that is crosswise to the length of the fastener shown in FIGS.  1 B, the view taken along line  27 D- 27 D of FIG. 26. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0051]    Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views, FIG. 1 shows five types of fasteners  1  for embodying the process according to the invention.  
         [0052]    These fasteners include two strips  2 ,  4 . As shown in the figure, the strips  2 ,  4  respectively include webs  6 ,  8  and fastener profiles  10 ,  12 . Profiles  10 ,  12  extend on the strips  2 ,  4  in the longitudinal direction thereof. Profiles  10 ,  12  have forms capable of interlocking in a complementary manner. For example, one of the profiles  10 , known as the male profile, has the shape of an arrowhead in cross-section. Profile  10  can be introduced and kept engaged in profile  12 , known as the female profile, which is in the form of a groove. Each strip  2 ,  4  can have a number of profiles  10 ,  12  similar, for example, to those described above. These profiles  10 ,  12  are then parallel to each other. Strips  2 ,  4  respectively include a first web  6  and a second web  8 , which extend substantially laterally on one side of the profiles  10 ,  12 .  
         [0053]    According to certain variants of the invention, the first web  6  and the second web  8  can be replaced by a first part  6  and a second part  8  of a single web that makes it possible to join the two strips  2 ,  4 .  
         [0054]    The fasteners shown in FIGS. 1A and 1B include two complementary profiles  10 ,  12 . Each profile  10 ,  12  is supported by one of the two parts  6 ,  8  of a single web which has a U-shaped cross-section with respect to the longitudinal direction of profiles  10 ,  12 . Profiles  10 ,  12  of the fastener  1  shown in FIG. 1A are close to the bottom of the U-shaped cross-section. Profiles  10 ,  12  of the fastener  1  shown in FIGS.  1 B- 1 E are close to the free ends of the U-shaped cross-section, thereby allowing placement of an opening slider, as will be discussed below. Webs  6 ,  8  of the fastener  1  shown in FIGS.  1 C- 1 E are independent of each other.  
         [0055]    These fasteners  1  are particularly adapted to be attached to the film  50  by the process according to the invention, since the surface of the webs  6 ,  8  permits welding onto the film  50  on an area of the webs not under profiles  10 ,  12 . This facilitates placement of the fastener  1  and welding the same to the film  50 . Preferably, at least one web  6 ,  8  extends sideways onto an area at least equal in surface area to the area located under profiles  10 ,  12 . Preferably, the process according to the invention is used to form reclosable bags  30  on an FFS machine  100 , shown in FIG. 3.  
         [0056]    In this case, during the process according to the invention, the step of attaching the first web to a film  50  is executed upstream of a filling tube  130  of the FFS machine  100 . The film  50  moves toward the tube  130  in the direction indicated by arrow D. The film  50  has two free longitudinal edges  52 ,  54  parallel to its direction of movement.  
         [0057]    A fastener  1  is brought crosswise with respect to the direction D of the movement of the film  50 . As shown in FIG. 2, the fastener  1  is oriented toward the film  50  so that the longitudinal direction of profiles  10 ,  12  is perpendicular to the longitudinal edges  52 ,  54  of the film  50 . Fastener  1  can be any one of the five fasteners  1  shown in FIG. 1 or may be any other fastener  1 , including those shown hereinbelow, adapted for implementation of the process according to the invention.  
         [0058]    Preferably, the length of the fastener  1  is approximately equal to half the size of the film  50  with respect to the direction of movement D thereof. The fastener  1  may be placed near one of the longitudinal edges  52 ,  54  of the film  50 . Preferably, the fastener  1  is attached approximately centered with respect to the two longitudinal edges  52 ,  54 . The fastener  1  is guided, pulled or pushed by roller-equipped means and/or by a two-way mechanism so that it is properly positioned on the surface of the film  50 . The fastener  1  is positioned on a portion of the film  50  suitable for forming a first bag wall so that one of the two strips  2 ,  4  is placed flat on one face of the film  50 . The strip  2  with the first web  6  rests on the surface of the film  50 . Prior to being positioned on the film  50 , fastener  1  is advantageously provided with two spot welds  42 ,  44 . Each spot weld  42 ,  44  is situated at one longitudinal end  3 ,  5  of the strips  2 ,  4  and, more particularly, at the location of profiles  10 ,  12 , and thus helps ensure that the fastener  1  is watertight at the longitudinal ends of the profiles  10 ,  12 .  
         [0059]    Fastener  1  is placed on the film  50  under first transversal welding means  110 . These first transversal welding means  110 , for example, include a welding bar  112  that is crosswise with respect to the direction of movement D of the film  50 , and two welding bars  114  that are longitudinal with respect to the direction of movement D of the film  50 . The length of the welding bar  112  is approximately equal to that of fastener  1 . The two welding bars  114  are located at the ends of the welding bar  112 , at right angles thereto, and the welding bars  114  are approximately equal in length to the width of fastener  1 . The welding bars  112 ,  114  are lowered and pressed onto the edge of webs  6 ,  8 , either together or independently of each other.  
         [0060]    Thus, according to one variant of the process, the step of attaching the first web  6  to the film  50  is performed only at the longitudinal ends  3 ,  5  of the strips  2 ,  4  by the longitudinal welding bars  114 . According to another variant of the process, the first web  6  is attached to the film  50  through the welding bar  112  only on the edge of the web  6  which will be toward the outside of the reclosable bag  30  with respect to profiles  10 ,  12  when the reclosable bag  30  is formed. According to still another variant of the process, the first web  6  is attached upstream of the tube  130  by combining the two preceding variants.  
         [0061]    According to still another variant of the process, the second web  8  of the fastener, shown in FIG. 1D, is attached to the film  50  through the welding bar  112 . The second web is preferably attached by a peel seal  11  on the edge of the web  6  which will be toward the inside of the reclosable bag  30  with respect to profiles  10 ,  12  when the reclosable bag  30  is formed. (See FIG. 27) According to still another variant of the process, the second web  8  is attached upstream of the tube  130  by combining the two preceding variants for the first web  6  at an earlier sealing point when the film is moved in direction D.  
         [0062]    Alternatively, for certain fasteners  1  the first web  6  is attached at no less than two points  47 ,  49  situated on either side of the profile  10  supported by the first web  6  with respect to the longitudinal direction. The first web  6  is thus attached as part of the film  50  at a given point toward the front and at a point located to the rear with respect to the direction of movement D. This makes it possible to prevent fastener  1  from being turned around during the formation of the reclosable bag  30  on the tube  130  (FIGS. 2 and 21). A machine according to the invention can also allow implementation of this variant of the process.  
         [0063]    Alternatively, the fastener  1  can be attached to the film  50  prior to forming the reclosable bag  30  at the same time the spot welds  42 ,  44  are being made. In this case, the fastener  1  is moved on the film  50  even if the spot welds  42 ,  44  have not been made. Then, once the fastener  1  is in place, appropriate longitudinal welding bars  114  weld the longitudinal ends  3 ,  5  of strips  2 ,  4  in the same operation that makes the weld points  42 ,  44 .  
         [0064]    [0064]FIG. 3 shows the formation of the reclosable bag  30  from the film  50  around the tube  130 . The film  50  with the fastener  1  is conveyed toward the tube  130 . The film  50  is then wrapped around tube  130 . The free longitudinal edges  52 ,  54  are positioned one over the other parallel to the axis of the tube  130  to be welded to one another by longitudinal welding means  120 , which is capable of forming a longitudinal weld seam  40 . By folding the film  50  longitudinally with respect to its direction of movement, a second wall  34  of the reclosable bag  30  is formed.  
         [0065]    The reclosable bag  30  has two longitudinal folds  31 ,  33  and an opening that is closed by fastener  1 . The reclosable bag  30  is hermetically sealed by the longitudinal weld  40  and one transversal weld  46 . The transversal weld  46  extends between the longitudinal folds  31 ,  33  and is located on the edge of the walls  32 ,  34  longitudinally opposed to the fastener  1 .  
         [0066]    [0066]FIG. 4 shows second transversal welding means  116 . The second transversal welding means  116  is adapted to attach the second web  8  of the fastener  1  to the second wall  34  of the reclosable bag  30  below the tube  130 .  
         [0067]    As shown in FIG. 5, the second transversal welding means  116  simultaneously makes it possible to weld the fastener  1  to the walls  32 ,  34  and to form the transversal weld  46 . Preferably, cutting means  140  are solidly joined to second transversal welding means  116  in order to cut successive bags  30 . The cutting means  140  can form a cut that is crosswise to the direction of movement of the film  50 .  
         [0068]    Preferably, the second transversal welding means  116  also includes grooves  117 , which extend over the entire length of the second transversal welding means  116 . The grooves  117  of each of the second welding means  116  are facing one another and are turned toward each another to form a cavity. These grooves  117  make it possible to avoid welding the walls  32 ,  34  in a small transversal area downstream of the fastener  1 . This transversal area makes it possible to form tongues  36 ,  38  that allow the walls  32 ,  34  to be grasped to spread the walls apart and to open the reclosable bag  30 . Alternatively, the formed tongues  36 ,  38  may be sealed at a peel seal  57  to provide a protective film around the fastener  1  and the attached slider  9 , as shown in FIGS.  27 - 27 D and described below.  
         [0069]    A number of additional variants of the fastener  1  for implementing the process according to the invention will be described hereinbelow. According to one of these variants, the fastener  1  includes the slider  9 . The slider  9  can be of any known type capable of engaging the profiles  10 ,  12  when moved in a first direction and disengaging the profiles  10 ,  12  when moved in a second direction opposite the first direction. The process of making film  50  must be adapted to attach fasteners  1  with the slider  9 . In one variant, as shown in FIG. 3A, the process includes a step of positioning film  50 , which include a first cutout  51 , before the tube  130 . The first cutout  51  permits access to the slider  9  over the entire length of the profiles  10 ,  12 . For example, the form and dimensions of the first cutout  51  are slightly smaller than those of the fastener  1 . The first cutout  51  is spaced apart on the film  50  by a distance equal to the dimension of the reclosable bag  30  in the direction parallel to movement D of the film  50 . The process then includes a step of positioning fastener  1  on the first cutout  51  before the filling tube  130 .  
         [0070]    Another variant of access to the slider  9  is to seal the tongues  36 ,  38  at a peel seal  57  to form film extensions to protect the fastener  1  and the attached slider  9 , as shown in FIGS.  27 - 27 D. Alternatively, a line of weakness  55  may be formed in the film extensions or the tongues  36 ,  38  by a cutting means  142 . The perforations  55  or the peel seal  57  allow the user to tear either the perforations or the peel seal in order to access the fastener  1  and the slider  9 .  
         [0071]    The fastener  1  is already provided with the slider  9 , and the longitudinal ends  3 ,  5  are possibly already welded together at spot welds  42 ,  44  which can act as end stops. The fastener  1  is therefore positioned and attached by the welding means  110  so that the slider  9  is on the longitudinal edge of the fastener  1 , located toward the front with respect to the direction of movement D of the film  50 .  
         [0072]    When using a cutout to access the slider, at least one of the webs  6 ,  8  is welded to the film  50  on at least one edge of the first cutout  51  by the first transversal welding means  110 . The film  50 , thus provided with the fastener  1 , is shaped in the form of a cylinder around the tube  130 . A longitudinal weld  40  is formed by the longitudinal welding means  120 . A second cutout  53  may be made downstream of the longitudinal welding means  120 . The second cutout  53  would be made in the film  50  opposite to the first cutout  51 , with the shape and dimension of this second cutout  53  being the same as those of the first cutout  51 . A second cutout is made by a blade  135 . If the blade  135  is located at the location of the tube  130 , the blade  135  is curved. The fastener  1  is then welded by the second transversal welding means  116 . The shape of second transversal welding means  116  is adapted to weld fasteners  1  that include the slider  9  by allowing passage of the slider by a groove  118  to the area of the weld.  
         [0073]    Examples of transversal welding means are illustrated in FIGS. 4A, 5A,  26  and  27 - 27 D. As shown in FIGS. 4A and 26, the second transversal welding means  116  includes an opening  119 . This opening  119  is parallel to profiles  10 ,  12  and is approximately equal in length to the profiles  10 ,  12 . This opening is wide enough so that the welding bars of the second welding means  116  are not applied to the slider  9  during welding of the fastener  1  onto the film  50 . The second welding means  116  therefore weld only webs  6 ,  8  of the fastener  1  to the film  50 , along with the longitudinal ends  3 ,  5  of strips  2 ,  4 . The second welding means  116  thus form transversal welds  46 ,  48  of the reclosable bag  30 .  
         [0074]    As shown in FIGS.  5 A and  27 - 27 D, according to another variant of the second transversal welding means  116 , these means have a U-shaped cross-section. This shape creates grooves  117  that form a cavity capable of receiving profiles  10 ,  12  and the slider  9  without deforming them when the welding bars of the second welding means  116  are pressed against each other to form the transversal welds  46 ,  48  and/or the peel seal  57 .  
         [0075]    Other methods can be envisaged for attaching a fastener  1  with the slider  9  to a film  50 . In particular, it is possible to clear access to the slider  9  when making the cutouts  51 ,  53  in ways other than those described above.  
         [0076]    As shown in FIG. 3A, the filling tube  130  may also be provided with a longitudinal groove or guiding ribs  132  capable of guiding the slider  9  toward the groove  118  of the second welding means  116  when the fastener  1  moves over filling tube. Additionally, a forming collar  134  may be provided with a trough leading to a groove  136  that guides the slider  9  into precise alignment with the longitudinal groove or the guiding ribs  132  of tube  130 .  
         [0077]    [0077]FIG. 6 shows a fastener  1  which, in addition to webs  6 ,  8  and profiles  10 ,  12 , has two strips  18 ,  20  that can form a peel seal. Peel seal strips  18 ,  20  extend over the entire length of the fastener  1  at the edges of the free ends of the webs  6 ,  8 . Peel seal strips  18 ,  20  thus join the webs  6 ,  8  or parts of the webs on the side that will be located toward the outside of the reclosable bag  30  with respect to profiles  10 ,  12  after the reclosable bag  30  is fully formed.  
         [0078]    With regard to the second transversal welding means  116 , FIG. 7A illustrates the positioning and welding of the fastener  1  to the walls  32 ,  34 . The fastener  1  shown in FIG. 6 is shown in FIG. 7A in a closed configuration. The peel seal strips  18 ,  20  are prewelded to each other. The free end of web  6  of fastener  1  is attached to the wall  34  by the first welding means  110 . It is possible, according to one variant of the process, that the peel seal strips  18 ,  20  are not prewelded and are then welded together and to the wall  34  during the step of attaching the web  6  to this wall by the first welding means  110 . According to still another variant of the process, the entire set of walls  32 ,  34 , webs  6 ,  8  and peel seal strips  18 ,  20  are welded by the second transversal welding means  116 . After the wall  32  has been brought close to the free edge of web  8 , the process of attaching fastener  1  to the walls  32 ,  34  is completed at the same time the weld  46  is formed and at the same time the walls  32 ,  34  between the weld  46  of the reclosable bag  30  and the fastener  1  of the following reclosable bag (FIG. 7B) are cut. As described above, the groove  117  of the second transversal welding means  116  makes it possible to keep two areas of the walls  32 ,  34  unwelded in order to create tongues  36 ,  38  on the side of the profiles  10 ,  12  situated toward the outside of the reclosable bag  30 .  
         [0079]    [0079]FIG. 8 shows a fastener  1  with two protective bands  14 ,  16 . These protective bands  14 ,  16  extend over the entire length of the free longitudinal edges of the webs  6 ,  8 . These protective bands  14 ,  16  are equipped with a barrier layer on the faces that are to be placed opposite each other, which prevents the protective bands  14 ,  16  from being welded together. As shown in FIG. 9A, the fastener  1  is welded to the walls  32 ,  34  by second transversal welding means  116  which do not have grooves  117 . FIG. 9B shows that the walls  32 ,  34  are welded to the fastener  1 , both at the location of the peel seal strips  18 ,  20  and at the location of the protective bands  14 ,  16 . The protective bands  14 ,  16  are not welded together. Thus tongues  36 ,  38  are formed, which are capable of grasping the walls  32 ,  34  of the reclosable bag  30  in order to open the reclosable bag.  
         [0080]    [0080]FIG. 10 is a cross-sectional view of a fastener  1 , which is provided with a perforated line  22 . When the fastener  1  is in an open position, the perforated line  22  is located between profiles  10  and  12  at approximately equal distances therefrom. This perforated line  22  extends over the entire length of the fastener  1  at the bottom of the U-shaped groove formed by the fastener  1  when it is in a closed position. After the reclosable bag  30  is opened, the fastener  1  is torn at the perforated line  22  by separating the peel seal strips  18 ,  20  and the profiles  10 ,  12 .  
         [0081]    [0081]FIG. 11 shows a variant of the fastener  1  shown in FIG. 10. According to this variant, a thin web  7  forms the U-shaped groove between the profiles  10 ,  12 . Webs  6 ,  8  are shown extending on a side of the profiles  10 ,  12 . However, if the webs  6 ,  8  do not extend in a manner similar to the U-shape shown in FIG. 1B, the profiles may be provided with a slider  9  similar to the arrangement shown in FIG. 27C.  
         [0082]    This thin web  7  can easily be torn to open the reclosable bag  30 , but it ensures that the fastener  1  is substantially watertight. If thin web  7  extends sufficiently, it can be turned inside out toward and between the webs  6 ,  8  when the contents of the reclosable bag  30  are emptied to protect profiles  10 ,  12  from the contents of the reclosable bag  30 . Profiles  10 ,  12 , thus protected, remain clean and able to work together effectively when reclosing the reclosable bag  30 . Thin web  7  can also form a funnel or a pouring spout when it is pulled out from the reclosable bag  30  as shown, for example, in FIG. 12.  
         [0083]    For instance, to form a pouring spout, the thin web  7  comprises two substantially trapezoidal-shaped elements placed one above the other and joined together at the two nonparallel edges of the trapezoids and on the shorter of the two parallel edges. The length of the longer of the two parallel edges of the trapezoid is equal to the dimension of the reclosable bag  30  transversely with respect to the direction of movement D of the film  50 . These two non-parallel edges are welded between and with the longitudinal ends  3 ,  5  facing strips  2 ,  4 .  
         [0084]    [0084]FIG. 13 shows a fastener  1  that, in addition to the peel seal strips  18 ,  20 , includes a gasket membrane  26 , the complementary profiles  10 ,  12  and the webs  6 ,  8 . The gasket membrane  26  is welded over the entire length of the fastener  1 , for example, close to the peel seal strip  18  between the peel seal strip  18  and the profile  10 . The gasket membrane  26  extends sideways toward the other profile  12  and covers the profile  10 .  
         [0085]    [0085]FIG. 14 shows the fastener  1  shown in FIG. 13 in the closed position. It is clearly shown that the sealing membrane  26  is engaged between profiles  10  and  12 .  
         [0086]    [0086]FIG. 15 shows a fastener  1  similar to that illustrated in FIGS. 13 and 14, except that fastener  1  shown in FIG. 15 includes two gasket membranes  26  each welded to one of the webs  6 ,  8 . It will be appreciated that the gasket membranes  26  of the foregoing embodiments may include a perforation located in close proximity to the point of attachment of the gasket membrane  26  to the webs  6 ,  8 . Such a perforation facilitates removal of gasket membrane  26  from webs  6 ,  8 .  
         [0087]    [0087]FIGS. 16 through 20 show variants of fastener  1  that include at least one peel seal strip  18 ,  20 ,  21  and a perforated line  19 .  
         [0088]    [0088]FIG. 16 shows a fastener  1  which has a single peel seal strip  21  attached between webs  6 ,  8 . The perforated line  19  is located on the edge of peel seal strip  21  located toward the outside of the reclosable bag  30  and between webs  6 ,  8 . This perforated line  19  extends over the entire length of the fastener  1  and permits the peel seal strip  21  to be more easily pulled apart when the walls  32 ,  34  are separated to open the reclosable bag  30 .  
         [0089]    [0089]FIG. 17 shows a fastener  1  in an open configuration. The perforated line  19  is located between the profiles  10 ,  12  at approximately the same distance from each of the profiles  10 ,  12  at the junction point of webs  6 ,  8 . The peel seal strips  18 ,  20  run along this perforated line  19  over the entire length of the fastener  1 .  
         [0090]    [0090]FIGS. 19 and 20 show a fastener  1 , such as that shown in FIGS. 17 and 18, which also includes gasket membrane  26 . This gasket membrane  26  is welded to the web  8  close to the peel seal strip  20  and extends sideways above profile  12 .  
         [0091]    [0091]FIG. 21 shows the fastener  1  attached to the film  50  (for example, before passing over the filling tube  130  of an FFS machine). This fastener  1  comprises two webs  6 ,  8  connected together to form a U-shaped cross-section. The web  6  is attached to the film  50  by two weld points  47 ,  49  located on the web  6  on either side of the longitudinal direction of profile  10 . These weld points  47 ,  49  can be made before the fastener  1  is folded back onto itself to engage profiles  10 ,  12 . The weld points  47 ,  49  can extend more or less in the longitudinal direction of the strips  2 ,  4  or may extend over the entire length of the fastener  1 . According to another variant, the fastener  1  can be held onto the film  50  by only one weld point  47 . Preferably, in this case, weld point  47  is located downstream in relation to the movement D of the film  50  to prevent fastener  1  from turning upside down when passing over the filling tube  130 .  
         [0092]    Advantageously, one of these weld points  47 ,  49  is located on the side of the profiles  10 ,  12  which will be inside the reclosable bag  30  once it is formed. In this case, no equivalent facing weld point will be made on the second web  8 . Thus, a hinged configuration is created that gives the reclosable bag  30  greater resistance to internal pressure as seen, for example, in FIG. 22. Using the method described in FIGS. 21 and 22 for the fastener  1  of FIG. 1B, the hinged configuration with attached slider  9  is shown in FIG. 27D.  
         [0093]    [0093]FIG. 23 illustrates an alternative embodiment of the fastener  1  shown in FIG. 15. Fastener  1  includes a single gasket membrane  26 , which is welded on each end thereof to a respective one of webs  6 ,  8  on the interior side of the profiles  10 ,  12 . Alternatively, gasket membrane  26  may be attached to the walls  32 ,  34  of the reclosable bag  30 . The gasket membrane  26  is interposed between the profiles  10 ,  12  to form a fluid-tight seal between the interior and exterior of the reclosable bag  30 . The profiles  10 ,  12  may be engaged or disengaged, and the gasket membrane  26  may be perforated near the point of attachment to either one or both of the webs  6 ,  8 . Such a perforation facilitates removal of the gasket membrane  26  when the reclosable bag  30  is opened for the first time, thereby providing a tamper-evident barrier. Alternatively, the portion of the gasket membrane  26  located on the exterior side of the profiles  10 ,  12  may be perforated.  
         [0094]    [0094]FIG. 25 is a top plan view of another alternative for providing a tamper-evident slider-operated fastener, which requires replacing the cutouts  51 ,  53  with only side cuts  122  which extend above the longitudinal weld made by weld bars  110  for a short distance beyond profiles  10 ,  12 . Accordingly, a film extension  126  beyond the profiles  10 ,  12  and a slider  9  are formed by sealing the tongues  36 ,  38 . The film extension  126  comprising the tongues  36 ,  38  is formed by the cross-weld bars of the second welding means  116  as described above. Perforations  124  may also be made parallel and above the profiles. The resulting open-ended loop thus formed above the slider-operated fastener must be torn off along the perforations before the slider can be used to open the bag  30 . Alternatively, the film extension  126  may extend the length of the slider-operated fastener  1 , as shown in FIG. 26. The film extension  126  of FIG. 26 may be torn open at the perforations  55  or at the peel seal  57  shown in FIGS.  27 - 27 D.  
         [0095]    It will be appreciated that the gasket membrane  26  of the several embodiments described above may, if of sufficient thickness, be provided for maintaining the profiles  10 ,  12  out of engagement when attaching the fastener  1  to walls  32 ,  34 . It will be further appreciated that if the gasket membrane  26  is interposed between engaged or interlocked profiles  10 ,  12 , and a pulling action is enacted on the walls  32 ,  34  of a formed reclosable bag  30 , the gasket membrane  26  will act to separate the engaged or interlocked profiles  10 ,  12 .  
         [0096]    [0096]FIG. 24 illustrates a section of a tape  56  comprised of a series of fasteners  1 , which are provided with gasket membranes  26  according to any of the embodiments described above. The tape  56  includes cross-seals  58 , which define the extent of each fastener  1  and are spaced apart a distance approximately equal to the width of the reclosable bag  30  to be formed. The gasket membrane  26  includes a cutout portion  60  located in closed proximity to the cross-seals so that profiles  10 ,  12  may be positively engaged in the area of the cutout portion  60 . Profiles  10 ,  12  may be engaged or disengaged over the remaining length of gasket membrane  26 . The positive engagement area  62  of profiles  10 ,  12 , which substantially corresponds to the cutout portion  60  of gasket membrane  26 , ensures alignment of the profiles  10 ,  12  over the remaining length of the fastener  1  and the gasket membrane  26 .  
         [0097]    It is clear that the invention also extends to a machine for producing a film  50  to be used to form reclosable bags  30 , including first welding means  110 , which are transverse to the direction of movement of the film  50  and are capable of attaching a fastener  1  with webs  6 ,  8  to this film  50 .  
         [0098]    Thus, one obtains a film  50  for forming reclosable bags  30  with fasteners  1 . These fasteners  1  may be attached to the film  50  by only a first web  6 . Reclosable bags  30  may then be formed and completed from this film  50  provided with fasteners  1 , either on a bag forming machine to be used and filled later or on an FFS machine.  
         [0099]    The invention therefore also covers a forming, filling and sealing machine which includes first transversal welding means  110  upstream of a filling tube  130  and second transversal welding means  116  below the tube  130 . The term “transversal” is to be understood herein to refer to the direction of movement of the film  50 .  
         [0100]    It will be appreciated that, although the gasket membrane  26  has been described hereinabove as being welded or attached to one or both of the webs  6 ,  8 , the gasket membrane  26  may alternatively be welded or otherwise attached to one or both of the walls  32 ,  34  of the reclosable bag  30 .  
         [0101]    Thus, the several aforementioned objects and advantages of the invention are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

Technology Category: 7