Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to automatic package forming, filling and sealing machines involving fasteners, for example with complementary male and female profiles. This type of machine is often referred to as an FFS (“Form, Fill and Seal”) machine.  
           [0003]    2. Description of the Prior Art  
           [0004]    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 an 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 spout and transversely with respect to the direction of movement of the film. The fastener consists of 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.  
           [0005]    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 that is 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.  
           [0006]    It is therefore an object of the present invention is 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  
         [0007]    The above and other beneficial objects are attained by providing a process for the fabrication of a film 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 consists of a first strip supporting at least one reclosable profile in engagement with another reclosable profile, which is complementary thereto and supported by a second strip or part of the first strip. The second strip or 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 substantially laterally on one side of the profile or profiles supported thereby.  
           [0008]    These webs give the invention a number of advantages. Due 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 as to prevent damaging the profiles.  
           [0009]    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  
       [0010]    The above and other aspects, purposes and advantages of the invention will be apparent from a reading of the following detailed description. The invention will also be more fully understood when read in conjunction with the drawings in which:  
         [0011]    [0011]FIG. 1 is a perspective view of three examples of fasteners for embodying the process according to the invention;  
         [0012]    [0012]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;  
         [0013]    [0013]FIG. 3 is a perspective view of first and second means of welding the fastener, located upstream and downstream, respectively, of a filling tube of a bag forming machine according to the invention;  
         [0014]    [0014]FIG. 3A is a perspective view of a variant of the bag forming machine that is adapted for fixing fasteners, which include a slider;  
         [0015]    [0015]FIG. 4 is a top plan view of the second welding means of the bag-forming machine;  
         [0016]    [0016]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;  
         [0017]    [0017]FIG. 5 is a cross-sectional view of the filling tube and the second welding means taken along the line V-V of the bag forming machine shown in FIG. 4;  
         [0018]    [0018]FIG. 5A is a cross-sectional view of a variant of the second welding means, which is adapted for attaching fasteners that include a slider;  
         [0019]    [0019]FIG. 6 is a cross-sectional view of an example of a fastener for embodying the process according to the invention;  
         [0020]    [0020]FIGS. 7 a  and  7   b  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;  
         [0021]    [0021]FIG. 8 is a cross-sectional view of another example of a fastener for embodying the process according to the invention;  
         [0022]    [0022]FIG. 9 is a cross-sectional view that is crosswise to the length of the fastener shown in FIG. 8, of the second welding means and of the cutting means;  
         [0023]    [0023]FIG. 10 is a cross-sectional view of another example of the fastener;  
         [0024]    [0024]FIG. 11 is a cross-sectional view of yet another example of the fastener;  
         [0025]    [0025]FIG. 12 is a top plan view of a reclosable bag provided with another example of the fastener;  
         [0026]    [0026]FIG. 13 is a cross-sectional view of another example of the fastener;  
         [0027]    [0027]FIG. 14 is a cross-sectional view of the fastener shown in FIG. 13 in a closed configuration;  
         [0028]    [0028]FIG. 15 is a cross-section view of another variant of the fastener;  
         [0029]    [0029]FIG. 16 is a cross-sectional view of the top of a reclosable bag that includes another variant of the fastener;  
         [0030]    [0030]FIG. 17 is a cross-sectional view of another variant of the fastener;  
         [0031]    [0031]FIG. 18 is a cross-sectional view of the fastener shown in FIG. 17 in the closed configuration;  
         [0032]    [0032]FIG. 19 is a cross-sectional view of another variant of the fastener;  
         [0033]    [0033]FIG. 20 is a cross-sectional view of the fastener shown in FIG. 19 in a closed configuration;  
         [0034]    [0034]FIG. 21 is a cross-sectional view of a variant of the attachment of a fastener on a film;  
         [0035]    [0035]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;  
         [0036]    [0036]FIG. 23 is a cross-sectional view of yet another variant of the fastener;  
         [0037]    [0037]FIG. 24 is a top plan view of a tape of the fasteners; and  
         [0038]    [0038]FIG. 25 is a top plan view of a tamper-evident reclosable bag. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]    Those skilled in the art will gain an appreciation of the invention when viewed in conjunction with the accompanying drawings of FIGS.  1 - 25 , inclusive. The individual reference characters designate the same or similar elements throughout the several drawings.  
         [0040]    [0040]FIG. 1 shows three fasteners  1  for embodying the process according to the invention. These fasteners  1  include two strips  2 ,  4 . 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, in cross-section, the shape of an arrowhead. 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 profiles  10 ,  12 .  
         [0041]    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 second part  8  of a single web that makes it possible to join the two strips  2 ,  4 .  
         [0042]    The fasteners shown in FIGS. 1 a  and  1   b  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. 1 a are close to the bottom of the U-shaped cross-section. Profiles  10 ,  12  of fastener  1  shown in FIG. 1 b  are close to the free ends of the U-shaped cross-section. Webs  6 ,  8  of fastener  1  shown in FIG. 1 c  are independent of each other. Profiles  10 ,  12  of the fastener  1  shown in FIG. 1 c  are close to one free edge of webs  6 ,  8 .  
         [0043]    These fasteners  1  are particularly adapted to be attached to the film  50  by the process according to the invention, since the surface of webs  6 ,  8  permits welding of these webs  6 ,  8  onto the film  50  on an area of the webs that is 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 100 machine.  
         [0044]    In this case, during the process according to the invention, the step of attaching the first web  6  to a film  50  is executed upstream of a filling tube  130  of the FFS 100 machine. FIG. 2 shows a portion of the film  50  to be used to form the reclosable bags  30 . 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.  
         [0045]    A fastener  1  is brought crosswise with respect to the direction D of movement of the film  50 . 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 three fasteners  1  shown in FIG. 1 or may be any other fastener  1 , including those shown herein below, adapted for implementation of the process according to the invention.  
         [0046]    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 free longitudinal edges  52 ,  54  of film  50 . Preferably, fastener  1  is attached approximately centered with respect to the two free longitudinal edges  52 ,  54 . 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 . Fastener  1  is positioned on a portion of the film  50  suitable for forming a first bag wall  30  so that one of the two strips  2 ,  4  is placed flat on one face of the film  50 . In FIG. 2, strip  2  with web  6  rests on the surface of the film  50 . Fastener  1  is advantageously provided, prior to being positioned on the film  50 , 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 to ensure that the fastener  1  is watertight at the longitudinal ends of the profiles  10 ,  12 .  
         [0047]    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 welding bar  112 , at right angles thereto, and 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.  
         [0048]    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 to 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 is going to be toward the outside of the reclosable bag  30  with respect to profiles  10 ,  12  when this 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.  
         [0049]    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 web  6 , with respect to the longitudinal direction. The first web  6  is thus 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 this invention can also allow implementation of this variant of the process.  
         [0050]    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 .  
         [0051]    [0051]FIG. 3 shows the formation of a reclosable bag  30  from the film  50  around the tube  130 . The film  50  with a fastener  1  is conveyed toward the tube  130 . The film  50  is then wrapped around tube  130 . The free longitudinal edges  52 ,  53  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  in this way, longitudinally with respect to its direction of movement, a second wall  34  of reclosable bag  30  is formed.  
         [0052]    A 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 .  
         [0053]    [0053]FIG. 4 shows second transversal welding means  116 . These second transversal welding means  116  are adapted to attach the second web  8  of fastener  1  to the second wall  34  of reclosable bag  30  below the tube  130 .  
         [0054]    As shown in FIG. 5, the second transversal welding means  116  simultaneously make it possible to weld the fastener  1  to the walls  32 ,  24  and to form the transversal weld  46 . Preferably, cutting means  140  are joined solidly to second transversal welding means  116 , in order to cut successive bags  30 . These cutting means  140  can form a cut that is crosswise to the direction of movement of the film  50 .  
         [0055]    Preferably also, the second transversal welding means  116  each include a groove  117 , which extends 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 one 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 same apart and to open up the reclosable bag  30 .  
         [0056]    A number of additional variants of the fastener  1  for implementing the process according to the invention will be described herein below. According to one of these variants, the fastener  1  includes a slider  9  (FIG. 5A). 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 to first direction. The process for making film  50  must be adapted to attach fasteners  1  with such a slider  9 . In particular, as shown in FIG. 3A, the process includes a step of positioning film  50 , which includes first cut-outs  51 , below the tube  130 . The first cut-outs  51  permit access to the slider  9  over the entire length of the profiles  10 ,  12 . For example, the form and dimensions of first cut-outs  51  are slightly smaller than those of the fastener  1 . These first cut-outs  51  are 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 each of the first cut-outs  51 , below the filling tube  130 .  
         [0057]    The fastener  1  is already provided with slider  9 , and the longitudinal ends  3 ,  5  are possibly already welded together at spot welds  42 ,  44 . The fastener  1  is therefore positioned 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 . At least one of the webs  6 ,  8  is then welded to the film  50  on at least at one edge of the first cut-outs  51  by the first transversal welding means  110 . The film  50  thus provided with fasteners  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 cut-out  53  is made downstream of the longitudinal welding means  120 . This second cut-out  53  is made in the film  50  opposite to the first cut-out  51 . The shape and dimension of this second cut-out  53  are the same as those of the first cut-outs  51 . The second cut-outs  53  are made by a blade  135 . If 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 slider  9 .  
         [0058]    Examples of transversal welding means  116  are illustrated in FIGS. 4A and 5A. As shown in FIG. 4A, the second transversal welding means  116  includes an opening  118 . This opening  118  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 welding means  116  therefore weld only webs  6 ,  8  of the fastener  1  to film  50 , along with the longitudinal ends  3 ,  5  of strips  2 ,  4 . The second welding means  1   16  thus form transversal welds  46  and  48  of reclosable bag  30 .  
         [0059]    As shown in FIG. 5A, 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  and  48 . The peel seal strips  18 ,  20  may be positioned between the webs  6 ,  8  of the side of the webs  6 ,  8  intended to be toward the inside of the reclosable bag  30 .  
         [0060]    Other methods can be envisaged for attaching a fastener  1  with a slider  9  to a film  50 . In particular, it is possible to clear access to the slider  9  when making the cut-outs  51 ,  53  in ways other than those described above.  
         [0061]    It may also be envisaged that the tube  130  can be provided with a longitudinal groove or guiding ribs capable of guiding the slider  9  when the fastener  1  moves over tube  130 . Additionally, a forming collar may be provided with a trough leading to a groove that guides the slider into precise alignment with the longitudinal groove or guiding ribs of the tube  130 .  
         [0062]    [0062]FIG. 6 shows a fastener  1  which has, in addition to webs  6 ,  8  and profiles  10 ,  12 , 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 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.  
         [0063]    [0063]FIG. 7 a  illustrates, with regard to the second transversal welding means  116 , the positioning and welding of the fastener  1  to the walls  32 ,  34 . The fastener  1  shown in FIG. 6 is shown in FIG. 7 a  in a closed configuration. The peel seal strips  18 ,  20  are prewelded to one another. 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  34  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 that the weld  46  is formed and at the same time that the walls  32 ,  34  between the weld  46  of a reclosable bag  30  and the fastener  1  of the following reclosable bag (FIG. 7 b ) 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 .  
         [0064]    [0064]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. 9, fastener  1  is welded to the walls  32 ,  34  by second transversal welding means  116 , which do not have grooves  117 . FIG. 9 b  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  30 .  
         [0065]    [0065]FIG. 10 is a cross-sectional view of a fastener  1 , which is provided with a perforated line  22 . The perforated line  22  is, when the fastener  1  is in an open position, 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 .  
         [0066]    [0066]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 . This thin web  7  can easily be tom 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 pouring spout when it is pulled out from the reclosable bag  30 , as shown, for example, in FIG. 12.  
         [0067]    To form a pouring spout, for instance, the thin web  7  consists of two substantially trapezoidal-shaped elements placed one over the other and joined together at the two non-parallel 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 .  
         [0068]    [0068]FIG. 13 shows a fastener  1  that includes, a gasket membrane  26  in addition to peel seal strips  18 ,  20 , the complementary profiles  10 ,  12  and the webs  6 ,  8 . Membrane  26  is welded over the entire length of the fastener  1 , for example, close to the peel seal strip  18  between this peel seal strip  18  and profile  10 . This gasket membrane  26  extends sideways toward the other profile  12  and covers profile  10 .  
         [0069]    [0069]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 .  
         [0070]    [0070]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 foregoing embodiments may include a perforation located in close proximity to the point of attachment of the gasket membrane  26  to the web  6 ,  8 . Such perforation facilitates removal of gasket membrane  26  from web  6 ,  8 .  
         [0071]    [0071]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 .  
         [0072]    [0072]FIG. 16 shows a fastener  1 , which has a single peel seal strip  21  attached between webs  6  and  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  and  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  and  34  are separated to open the reclosable bag  30 .  
         [0073]    [0073]FIG. 17 shows a fastener  1  in an open configuration. The perforated line  19  is located between profiles  10  and  12 , at approximately the same distance from each of profiles  10 ,  12 , at the junction point of webs  6 ,  8 . Peel seal strips  18 ,  20  run along this perforated line  19  over the entire length of the fastener  1 .  
         [0074]    [0074]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 .  
         [0075]    [0075]FIG. 21 shows fastener  1  attached to a film  50  (for example before passing over the filling tube  130  of an FFS machine). This fastener  1  consists of 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 the located downstream in relation to the movement D of the film  50 , so as to prevent fastener  1  from turning upside down when passing over the filling tube  130 .  
         [0076]    Advantageously, one of these weld points  47 ,  49  is located on the side of 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.  
         [0077]    [0077]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 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.  
         [0078]    [0078]FIG. 25 is a top plan view of another alternative for providing a tamper-evident slider-operated fastener, which requires replacing the cut-outs  51  and  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 slider  9  is formed. The film extension  126  is then sealed by cross-weld bars  116 . Perforations  124  parallel and above the profiles may also be made. The resulting open-ended loop thus formed above the slider-operated fastener must be tom off along the perforations before the slider can be used to open the bag  30 .  
         [0079]    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 , a pulling action 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 .  
         [0080]    [0080]FIG. 24 illustrates a section of a tape  56  being comprised of 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 cut-out portion  60  located in closed proximity to the cross-seals  58  so that profiles  10 ,  12  may be positively engaged in the area of the cut-out 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 cut-out portion  60  of gasket membrane  26 , ensures alignment of the profiles  10 ,  12  over the remaining length of fastener  1  and gasket membrane  26 .  
         [0081]    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 transversal to the direction of movement of the film  50 , and capable of attaching a fastener  1  with webs  6 ,  8  to this film  50 .  
         [0082]    Thus, one obtains a film  50  for forming reclosable bags  30  with fasteners  1 . These fasteners  1  may be attached to the film  50  only by a first web  6 . Recloseable 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.  
         [0083]    The invention therefore also covers a forming, filling and sealing machine which include first transversal welding means  110  upstream of a filling tube  130  and second transversal welding means  116  below the tube  130 . The term transversal to be understood herein to refer to the direction of movement of the film  50 .  
         [0084]    It will be appreciated that although the gasket membrane  26  has been described hereinabove 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 .  
         [0085]    Thus, the several aforementioned objects and advantages are most effectively attained. Although a single preferred embodiment of the invention has 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: b