Abstract:
A machine and a method for wrapping an elongated object, such as a drinking straw, with a plastic film are disclosed. The machine has a drive for continuously advancing a thin narrow film strip from a supply roll to a wrapper loading and forming station. The wrapper loading and forming station has a trough former for folding the advancing film strip into a film trough. An inserting device positions spaced-apart elongated objects, such as the drinking straws, into the film trough of the advancing film strip for engagement by the film trough. The objects are supplied by a dispenser and disposed in a pre-oriented manner to be grasped by the inserting device. The film trough is advanced through sealing and severing stations wherein individually wrapped elongated objects or straws are produced.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of Application Ser. No. 09/391,011, filed Sep. 7, 1999. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention relates to a machine and a method for wrapping an elongated object, such as a drinking straw, with a plastic film, and to the wrapped object resulting therefrom. More specifically, the invention relates to a straw wrapping machine and method and a straw wrapped in a plastic film wrapper which seals the straw therein. The machine can also be retrofitted quite easily to convert to a paper straw wrapper.  
         BACKGROUND ART  
         [0003]    Straws of all types are packaged in different manners whereby to protect the straw in a sanitary manner to prevent contamination thereof. It is also known to package thermometers in sterilized wrappers. It is still further known to attach short drinking straws on beverage packages or cans with shrink wrappers or other straw attaching films. However, the majority of straws are packaged individually in thin paper wrappers of the type commonly used to manufacture cigarettes. A disadvantage of such wrappers is that they cannot be used to sterilize the straws due to their absorbency. Furthermore, because these papers are highly absorbent, they are susceptible to contamination by liquids should liquid be splashed against the wrapped straw or the straw placed on a liquid spill which we often find on counter tops where drinks of all sorts are dispensed. Another disadvantage of using these thin paper wrappers is that it is difficult to print on these papers. Also, because the paper is highly absorbent, if the wrapped straw was in contact with liquid, the liquid could also dissolve the ink and contaminate the straw inside the wrapper. A further disadvantage is that because these straws are usually made of plastics material, it is difficult to recycle straws in their paper wrappers as the two materials need to be separated for recycling. Accordingly, they are destroyed and not recycled.  
         SUMMARY OF INVENTION  
         [0004]    It is a feature of the present invention to provide a machine, a method and a plastic film wrapped straw which substantially overcomes the above-mentioned disadvantages of the prior art.  
           [0005]    Another feature of the present invention is to provide a machine for automatically wrapping straws with a thin plastic film strip which is contained in a roll and wherein the plastic film is a co-extruded film structure with a sealing layer permitting high line speed and a core providing the rigidity and mechanical properties required for good machinability and which permits a substantial increase in film length as compared to paper straw wrappers of the same diameter roll thereby resulting in less frequent machine stoppage for reloading of wrapper strip rolls.  
           [0006]    Another feature of the present invention is to provide a method of wrapping straws with thin plastic film strips which is substantially fully automatic and which can handle elongated tubular objects, such as straws, of different dimensions.  
           [0007]    Another feature of the present invention is to provide a straw sealed in a thin plastic film wrapper which is water-proof and on which wrapper there is provided printed matter and/or graphics.  
           [0008]    Another feature of the present invention is to provide a straw wrapped in a thin plastic film and wherein the straw and wrapper are completely recyclable by the manufacturer.  
           [0009]    Another feature of the present invention is to provide a thin plastic wrapper for elongated articles and wherein the wrapper is completely sealed and can be easily sterilized.  
           [0010]    Another feature of the present invention is to pre-stretch the film strip to increase the yield of a supply roll and to weaken the film to facilitate the removal of a straw wrapped by said pre-stretched film.  
           [0011]    A still further feature of the present invention is to provide a thin plastic film straw wrapping machine which can be easily and economically converted to a paper straw wrapping machine.  
           [0012]    According to the above features, from a broad aspect, the present invention provides a machine for wrapping an elongated object with a plastic film. The machine comprises drive means for continuously advancing a narrow thin film strip from a supply means to a wrapper loading and forming means. The wrapper loading and forming means has a trough former for folding the advancing film strip into a film trough. Insert means is provided for positioning spaced-apart elongated objects into the film trough of the advancing film strip for engagement of the objects and conveyance by the film trough. Object dispensing means is provided for supplying pre-oriented elongated objects to the insert means. Sealing and severing means are provided for heat sealing the film trough about individual ones of the elongated objects and severing the film trough between adjacent ends of the elongated objects to form individually wrapped elongated objects.  
           [0013]    According to a further broad aspect of the present invention there is provided a method of wrapping an elongated object, such as a straw, with a thin plastic film. The method comprises continuously advancing a narrow thin film strip from a supply roll to a wrapper loading and forming station by drive means. The narrow thin film strip is folded in a trough former to form a film trough having opposed spaced film side walls. Spaced-apart elongated objects are inserted into the advancing film trough whereby each object is frictionally engaged and conveyed by the film side walls of the film trough. A top end portion of the opposed film side walls is longitudinally sealed together with the object thereunder. The folded film trough is then transversely sealed and severed at opposed ends of the object therein and the plastic film wrapped objects are discharged.  
           [0014]    According to a still further broad aspect of the present invention, there is provided a straw held captive in a film wrapper formed by a narrow folded plastic film strip defining a trough having opposed side walls between which the straw is held captive between a longitudinal seal adjacent elongated end edges of the side walls and transverse seals spaced from opposed ends of the straw.  
           [0015]    According to a further broad aspect of the present invention there is provided an elongated object wrapped in a thin film strip formed by the above described method and apparatus and wherein the elongated object may be a thermometer, stir sticks or any such objects capable of being automatically dispensed in a plastic film trough as formed hereinabove by the described machine and method.  
           [0016]    According to a still further broad aspect of the invention the plastic film is a co-extruded polyolefin film structure comprising a sealing layer with a seal initiation temperature lower than 90° C. and a core comprising a mixture of low, medium and/or high density polyethylene and/or polypropylene with an approximate thickness of between 0.5 to 0.7 mil.  
           [0017]    According to a still further broad aspect the film strip is stretched by a controlled driven roll unit to increase the yield of a supply thin film roll and to weaken the film to facilitate the removal of a straw wrapped with said weakened film.  
           [0018]    According to a further broad aspect of the invention, the plastic film straw wrapping machine is retrofitted to provide a machine for wrapping an elongated drinking straw with a paper strip, said machine comprising drive means for continuously advancing a narrow paper strip from a supply means to a wrapper loading and forming means, said wrapper loading and forming means having a trough former for folding said advancing paper strip into a paper trough, insert means for positioning spaced-apart elongated drinking straws into said paper trough of said advancing paper strip for engagement and conveyance of said straws by said paper trough, straw dispensing means for supplying pre-oriented elongated straws to said insert means, crimping and severing means for crimping said paper trough about individual ones of said elongated straws and severing said paper trough between adjacent ends of said elongated straws to form individually wrapped straws, said trough former having a geometric forming plate with a tapered bottom wall having a flat inlet end and progressively merging opposed side walls tapering to a narrow funnel-like rear trough section, and paper trough drawing means spaced from said funnel-like rear end through section for pulling said paper strip in folded juxtaposition adjacent a top edge of said paper trough formed in said trough former. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0019]    A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:  
         [0020]    [0020]FIG. 1 is a side view of the plastic film wrapping machine of the present invention;  
         [0021]    [0021]FIG. 2 is a top view of FIG. 1;  
         [0022]    [0022]FIG. 3A is an enlarged side view of a portion of FIG. 1 to better illustrate the construction and operation of the wrapper loading and forming stations;  
         [0023]    [0023]FIG. 3B is a top view of the vertical sealer and severing roll assemblies;  
         [0024]    [0024]FIG. 4 is a still further enlarged view of a section of FIG. 3 showing the discharge end of the straw holding bin in relation to the endless belt straw inserter and its position relative to the trough former;  
         [0025]    [0025]FIG. 5 is a top view of the straw former and its relationship with the endless belt straw inserter;  
         [0026]    [0026]FIG. 6 is a perspective view of the plastic film trough former;  
         [0027]    [0027]FIG. 7 is a side view showing the construction of the holding bin with its straw feeding and alignment mechanisms to position the straws in side-by-side parallel relationship in a discharge magazine;  
         [0028]    [0028]FIG. 8 is an enlarged view of the horizontal throat section adjacent the discharge conveyor;  
         [0029]    [0029]FIG. 9 is a fragmented side view showing a section of the horizontal throat section of a discharge conveyor in relation to the buffer wall;  
         [0030]    [0030]FIG. 10 is a front end view of the holding bin and the storage magazine leading to the straw discharge end;  
         [0031]    [0031]FIG. 11 is an end view showing the construction of the adjustable outer wall of the magazine section of the holding bin;  
         [0032]    [0032]FIG. 12 is a side view showing the construction of the conveyor and its drive;  
         [0033]    [0033]FIG. 13 is a top view illustrating the construction of the film roll holder and automatic braking system;  
         [0034]    [0034]FIG. 14A is an enlarged view showing the construction of the film core lock assembly and the position of the brake shoe in relation to the brake hub secured to the film roll core support shaft;  
         [0035]    [0035]FIG. 14B is a side view of the brake shoe in relation to the brake hub secured to the film roll support shaft;  
         [0036]    [0036]FIG. 15 is a perspective view showing a straw wrapped in a thin film plastic strip formed in accordance with the present invention;  
         [0037]    [0037]FIG. 16 is a transverse section view of FIG. 15;  
         [0038]    [0038]FIG. 17 is a top view of paper crimping rolls which replace the heat sealing disc when the machine is retrofitted as a paper straw wrapper;  
         [0039]    [0039]FIG. 18 is a fragmented top view of the vertical crimping disc used for paper straw wrapping;  
         [0040]    [0040]FIG. 19 is a perspective view of a paper wrapped straw produced by the retrofit; and  
         [0041]    [0041]FIG. 20 is a side view of a portion of the machine illustrating the speed controlled film stretching unit. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0042]    Referring now to the drawings and more particularly to FIGS. 1 and 2, there is shown generally at  10  the machine of the present invention for wrapping an elongated object, such as a drinking straw  11 , as shown in FIGS. 15 and 16, in a thin plastic film wrapper  12 . The machine has a housing  13  which is supported on adjustable legs  14  whereby the machine can be leveled. The machine is also provided with a control panel  15  which houses switches, counters, temperature controllers, machine speed indicators, etc. At a supply end  16  of the machine, there is provided a thin plastic film strip roll  17  which is supported on a support shaft assembly  18 . A cylindrical flange  19  is secured to the top wall  20  of the housing at the supply end and a plurality of the film rolls  17  are stored about this cylindrical flange for reloading the machine once the dispensing roll needs to be replaced.  
         [0043]    As hereinshown, the thin plastic film strip  21  is trained about various guide rolls and is drawn by a drive feed roll  22  which is spring-biased against an idler roll  23 . The film strip  21  exiting the film roll  17  is first trained about a tension roller  24  which is secured to a pivot arm, as will be described later. The tension roller  24  is displaceable in an arcuate guide slot  25  for reasons which will also be described later. The film strip exiting the drive feed roll  22  is trained about a pair of guide rolls  26 ,  26 ′ which are disposed under an article loading conveyor  27 . The thin film strip  21  then passes over an inlet roll  28  of a trough former  29  where the thin film strip  21  is folded into a trough for receiving an elongated object, such as the straw  11  therein.  
         [0044]    At the outlet of the trough former, the free top end portions  12 ″ of the opposed side walls  12 ′ of the folded film strip are held captive between a set of draw rolls  30  driven by a belt which is synchronized to the drive feed roll  22  whereby to draw the film trough engaged in a closed folded position with the straw captive therein and disposed under the engaged top free end  12 ″ of the wrapper, as shown in FIG. 16. This top fee end  12 ″ is also engaged by a set of heat sealing disc flanges  32 ′ of the sealer  32  and which are also rotatably driven by a further belt drive, also synchronized with the drive feed roll  22  and draw rolls  30 . The sealing disc flanges  32 ′ are heated to a predetermined temperature to form an elongated seal  34  between opposed side walls  12 ′ of the film wrapper  12  below the top free ends  12 ″, and transverse end seals  41  as shown in FIG. 15. The film trough is then engaged between another set of driven drums  35  of an anvil  39  and knife  38  assembly  36  (see FIG. 3B) which is also driven by a belt synchronized with the other belts and the drive feed roll  22 .  
         [0045]    With further reference to FIG. 3, the vertical anvil and knife assembly  36 , as previously described, is comprised of a pair of drums  35  and  35 ′ with drum  35  being provided with a vertical cutting blade or knife  38  extending at a predetermined location and oriented on a vertical axis on the surface of the drum  35 . This cutting edge or blade  38  is disposed to contact the anvil  39 , disposed on the drum  35 ′ and positioned at a predetermined location on its outer circumference  40  and aligned for registry with the cutting blade  38  whereby to sever the film trough between opposed ends of adjacent straws being conveyed by the trough and to simultaneously form a vertical end seal  41  at both the trailing end of a forward straw wrapper and the leading end of a trailing straw wrapper. The folded film trough is drawn from the cutting head assembly  36  by a pair of discharge conveyors  42  which, as better seen from FIG. 2, is comprised by two endless belts  43  and  43 ′ and which form a discharge throat  44  by opposed straight runs of the belt to engage therebetween the top end portions  12 ″ of the film wrapper  12  having been completely sealed about the straw  11  and discharged from the cutting head assembly  36 . The straw  11  in its wrapper  12 , as shown at  45 , is then ejected by the discharge conveyor  42  into collecting bins, not shown, or other form of collator for packaging these film wrap straws.  
         [0046]    Referring now more specifically to FIGS.  4  to  6 , there will be described the construction and operation of the trough former  29  and the loading conveyor  27  which dispenses straws from a discharge end  46  of a straw holding magazine  47  of a straw supply bin  48  as shown more clearly in FIG. 1. As better seen from the perspective view illustrated in FIG. 6, the trough former  29  is comprised by a geometric forming plate which defines a tapered bottom wall  49  having a flat wide inlet end  50  and progressively merging opposed side walls  51  and  51 ′ tapering to a narrow funnel-like U-shaped rear trough section  52 . The film draw rolls  30  are spaced from the rear end trough section  52  and pull the film strip  21  in folded juxtaposition to progressively form a film trough  21 ′ within he forming plate and in which straws  11  are positioned. As clearly shown in FIG. 6, the draw rolls  30  are narrow rolls and engage only the top end portions of the folded film trough  21 ′ whereby the straw  11  can be conveyed below the narrow draw rolls  30  as it pulls the film trough  21 ′ through the plate former  29 . As the film moves into the trough former, the side walls  12 ′ of the film come closer together to form a straw engaging section intermediate the flat end  50  and the rear trough section  52  whereby when a straw is disposed in the trough former, the side walls  51 ,  51 ′ of the film will frictionally engage a leading end of the straw  11  loaded therein by the loading conveyor  27  and convey it, as better seen from FIGS. 4 and 5.  
         [0047]    As shown in FIG. 4, the geometric forming plate  29  is secured to an adjustable positioning flange  53  which is secured by bolts  54  extending into respective slots  55  of the flange whereby the position of the trough former  29  can be adjusted up and down and in relation to the inlet roll  28  whereby to ensure proper operation of the trough former to receive the particular objects being dispensed by the loading conveyor  27 .  
         [0048]    The loading conveyor  27  is comprised of a narrow endless belt  56  which is rotatably driven between a drive sheave  57  and an idle sheave  58 . The endless belt has a flat run section  59  which is disposed adjacent the straw discharge end  46  of the straw dispensing magazine  47  and is herein provided with three pusher plates  60  secured to the top surface  61  of the endless belt  56  in spaced-apart relationship and disposed a predetermined distance between one another. The pusher plates have a straw end engaging front wall for pushing a straw, such as straw  11 ′ at the discharge end  46 , into the trough forming plate  29 , as shown in FIG. 5. As the front end of the straw  11 ′ moves into the trough forming plate  49 , it will be frictionally engaged by the opposed side walls of the film trough  12  and will be grasped thereby and pulled through the trough former along with the film trough  21 ′. The pusher plates  60  are provided with an attachment lug  62  which constitutes an adjusting means to secure the position of the pusher plates along the top surface  61  of the endless belt  56  at predetermined distances dependent on the length of the objects, herein straws  11 , being loaded in the film trough.  
         [0049]    As previously described, the machine can also be adapted to load different elongated objects into the film trough  21  such as, for example thermometers, stir sticks, etc. As hereinshown, the drive sheave  57  is also secured to its drive shaft  63  through an adjustable connection comprised of bolts  64  extending in arcuate slot  65  formed in the sheave disc. This permits the adjustment of the belt and therefore the pusher plates  60  to position the plates at precise locations with respect to the trailing end position  66  of a straw  11 ′ located at the discharge end  46  of the magazine prior to the operation of the machine. Accordingly, the loading conveyor is also synchronized with the drive feed roll  22  and the motors  31 ,  33  and  37 .  
         [0050]    Referring now to FIGS.  7  to  11 , there will be described the construction and operation of the straw supply holding bin  48 . The straw supply holding bin  48  is formed by spaced-apart parallel side walls  67 , a front wall  68 , a rear wall  69  and a bottom wall  70 . A straw feed and alignment mechanism  71  is provided and forms a portion of the bottom wall in a discharge area thereof. This mechanism  71  is comprised of a discharge conveyor  72  which is provided by an endless belt  73  which has a serrated upper surface formed by a plurality of rib formations  74  or other means, as better illustrated in FIG. 9, wherein to frictionally engage on its surface the straws  11  which are disposed within the bin and transversely aligned between the side walls  67 . Supply means, not shown, is provided to position straws within the bin and this can be done manually or by other automatic loading means.  
         [0051]    The bin bottom wall  70  is an inclined wall whereby to direct the straws towards the discharge conveyor  72 . A further discharge conveyor  75  is also coupled to the drive sheave of the discharge conveyor  72  to feed the straws to the discharge conveyor  72  to position the straws into a positioning throat section  77  where the straws are oriented in perfect side-by-side parallel spaced relationship.  
         [0052]    With further reference to FIG. 8, it can be seen that the positioning throat section  77  is defined by a stationary buffer wall  78  retained in spaced parallel relationship with at least a section of the upper surface  74  of the discharge conveyor  72 . This buffer wall  78  permits the straws  11  to align themselves in the said side-by-side parallel spaced relationship.  
         [0053]    The buffer wall  78  is comprised by a plurality of spaced rods  79  which are secured to a frame  80  and held in spaced-apart parallel relationship and at a predetermined distance therebetween. These rods  79  lie in a common plane which is disposed substantially parallel to the friction upper surface  74  of the discharge conveyor belt which has a straight flat run section  59  disposed there adjacent. A flexible hollow tubular member  82 , which is herein constituted by a straw is disposed about each of the rods  79  in loose spaced relationship therewith. That is to say, the inner diameter of the tubular member  82  is much larger than the outer diameter of the rod  79  so that the tubular members  82  can move up and down and sideways and provide a buffer for the straws  11  being conveyed on the upper surface  61  of the flat run section  59  permitting the straws  11  to align themselves.  
         [0054]    The frame member  80  holding the rod  79  is secured to an adjustable flange wall  83  which is adjustable up and down to vary the distance between the tubular rod  79  and the upper surface  61  of the straight run section  59  of the discharge conveyor  72 . The flange wall  83  is secured by bolts  84  which extend through elongated slots  85  to provide this adjustment.  
         [0055]    It is pointed out that the discharge conveyor  72  is rotating at a speed slightly higher than the speed of the loading conveyor  27  to ensure that the discharge magazine  47  is always full of straws. Accordingly, as the straws enter the positioning throat section  77 , the upper surface of the conveyor  61  will keep pushing on the straws and they will move slightly up and down and align themselves in a side-by-side relationship as shown in FIG. 8 as they are free to move up against the flexible tubular members or straws  82  which will also move up and down on their support rods. Therefore the serrated upper surface of the endless belt  73  will slip under the straws when the trough and magazine is full but continue to move the straws in the discharge magazine immediately as straws are discharged from the discharge end  46  thereof.  
         [0056]    With reference now to FIGS. 7, 10 and  11 , there will be described the construction of the magazine. As hereinshown, the magazine is constituted by a lower vertical discharge section  81  of the bin  48 . At the upper end of the magazine  47 , the endless belt  73  is displaced along a straight vertical travel path  86  which extends substantially transverse to the horizontal straight run section  59  under the buffer wall so that straws will be continuously pushed into the magazine  47 . The magazine  47  is provided by adjustable straw restraining walls  87  and a stationary lower wall section  88 . An opposed adjustable plate  89  is provided below the lower wall section  88  to adjust the width of the discharge end  46 , depending on the size of the straws being packaged. Similarly, the straw restraining wall  87  is adjusted.  
         [0057]    As shown in FIGS. 10 and 11, the straw restraining walls  87  are comprised of a pair of spaced-apart guide plates  90  which are retained in vertical parallel relationship by adjustable support rods  91  which are secured between side frame members  92 , as shown in FIG. 10. These guide plates  90  are brass plates which are adjustably positioned relative to the vertical discharge section  86  of the discharge conveyor and depending on the outer diameter of the straws being loaded into, the magazine. As also better seen from FIG. 12, the discharge conveyor is constituted by two narrow endless belts  73  and  73 ′ trained about the drive sheave  71  and idle sheaves  71 ′. The drive shaft  93  of the drive sheave  76  extends outwardly of one of the side walls  67  of the bin for coupling to a drive motor (not shown) which is synchronized with the other drives as above-described.  
         [0058]    Referring now to FIGS. 2, 13 and  14 A, there is shown the construction of the support mechanism for the film roll  17  which feeds the machine. As hereinshown, the support mechanism is comprised of the support shaft  18  secured between pillow blocks  95  disposed inside the machine housing  13 . The support shaft is freely rotated within the pillow blocks  95  and has a connecting free end section  96  extending outside the housing and to which a core chock  97  is removably secured. The core chock  97  is selected to engage the specific film core  98  of the film roll  17  being dispensed. Another core chock  97 ′ is secured to a core lock ratchet cap  99  which is secured to the threaded free end  100  of the free end section  96  of the support shaft  18  whereby to clamp the film core  98  between the chocks  97 ,  97 ′. The ratchet cap  99  is provided with an internal ratchet connection  101  which ensures proper clamping pressure on the core to prevent slippage and the cap from disconnection during high-speed operation of the film roll  17 . As can be appreciated, as the film roll becomes smaller and smaller in diameter, the speed of the shaft increases. However, to control the speed of the shaft to maintain proper tension on the film, there is provided the tension roller  24 , which is displaceable in the arcuate slot  25  and this tension roller  24  is connected to a tension control pivot arm  102  which has a brake shoe  103  for releasable engagement with a brake hub  104  which is secured to the support shaft  18 , as can be seen from FIGS. 13 and 14A. The tension roller  24  is displaceable in the arcuate slot  25  on a pivot connection  105  located adjacent the brake hub  104 . Accordingly, the weight of this pivot arm  102  will maintain the tension roller biased downwardly within the arcuate slot  25  against the film strip  21 . As the machine drive slows down, the film roll has a tendency to keep turning at a higher speed and this will cause the tension roller  24  to start moving down within the arcuate slot on its pivot  105  causing the steel brake shoe  103 , as shown in FIG. 14B, to move against the drum and slow down the speed of the support shaft  18 . A roller  104  is engageable with the brake hub to limit the displacement of the brake shoe  103 .  
         [0059]    With the above dispensing mechanism we have found that large thin narrow film rolls of polyolefin co-extruded film structure comprising a sealing layer with a seal initiation temperature lower than 90° C. and a core comprising a mixture of low, medium and/or high density polyethylene and/or polypropylene with an approximate thickness of between 0.5 to 0.7 mil is a suitable film spec for use with this machine. This is a water-proof film on which printed matter can be printed therealong.  
         [0060]    With reference to FIG. 1, the method of operation of the machine will be briefly summarized. A narrow thin film roll  17  is placed on the support shaft  18  and locked therein by the ratchet cap  99 . The thin film strip  21  is trained about the tension roll  24 , over the idler roll  23  with the drive feed roll  22  having been sprung back. The film then extends in a lower travel path under the loading conveyor  27  between a pair of guide rolls  26  and  26 ′. The film is then positioned up on the inlet roll  28  and through the trough former  29  at the end of which the film is folded in half. As shown in FIG. 2, one of the draw rolls  30 , herein roll  30 ′ has a cam operated mechanism  109  secured thereto to draw the roll  30 ′ away from the stationary draw roll  30  to permit threading the folded film strip and more specifically the upper free end edge portions of the opposed side walls of the folded film through the draw rolls. The heat sealing discs  32  are provided with a pneumatic roll separating mechanism, not shown herein, and these are also opened so that both heated rolls  32 ′ separate to permit the folded film strip  21 ′ to be passed therebetween without engaging the heated rolls. The film is advanced to the first set of wheels  30  during start up. The film will self-feed through the heated section  32  as the machine starts. The loading conveyor pusher arms  60  are also adjusted with respect to the article at the discharge end of the magazine and the machine is ready for operation. The draw rolls  30  are closed so the machine can be started wherein immediately thereafter the sealing discs  32 ′ are closed as well as the vertical sealing and severing assembly  36 . This results in some waste of film material and straws at the beginning of the run. However, because both the film and the straws are made of compatible polyolefin materials, they are easy to recycle as there is no need to separate them. As previously described, the straws are ejected by the discharge conveyor  42  into holding bins or discharge conveyors (not shown) for packaging.  
         [0061]    As shown in FIGS. 15 and 16, there is thus formed a straw which is held captive in a thin film wrapper  12  formed by a narrow folded plastic film strip defining a trough having opposed side walls  12  and  12 ′ and between which a straw  11  is held captive between a longitudinal seal  34  formed adjacent elongated top end edges  12 ″ of the film side walls  12 ′ and transverse end seals  41  formed at opposed ends of the straw  11 .  
         [0062]    An important feature of the plastic film straw wrapping machine described is that it can be easily, quickly and economically converted to a paper straw wrapper. Accordingly, the machine may serve a dual purpose. To convert to a paper wrapping machine, a roll of paper is substituted for the plastic film roll  17  and may be mounted on a different roll support chuck. The draw rolls  30  can be changed to suit a paper strip. The heat to the sealing discs  32 ′ is switched off and the sealing discs are replaced by paper crimping discs  110  and  110 ′, as shown in FIG. 17. The paper strip  111  is folded by the trough former  29 , the same way as the plastic film strip and a straw is held captive therein. The free top end portion  112  of the folded paper strip extends juxtaposed in contact above the captive straw and engaged between the two crimping discs  110  and  110 ′ wherein the top edge  112  is engaged by crimps  113  formed therein by the teeth  114  and  114 ′ about the circumference of the discs  110  and  110 ′.  
         [0063]    The anvil and knife assembly  35  is also replaced by a set of vertical crimping and severing discs  115  and  115 ′, as shown in FIG. 18. As shown, crimping teeth  116  and  116 ′ are formed in a section only of these discs which is synchronized with portions of the folded paper strip  111  in the area between opposed spaced ends of adjacent straw held captive in the folded strip. Disc  115 ′ is provided with a cutting blade  117  and disc  115  is provided with a backing pad  118  aligned with the blade  117  whereby to sever the folded paper strip  111  in the vertical crimped area. End crimps  119  are thereby formed in the ends of the paper straw wrapper  120  as shown in FIG. 19.  
         [0064]    Referring now to FIG. 20, there is shown a partial view of a modification made to the machine as illustrated in FIG. 1 and wherein there is provided a speed controlled film stretching unit  130  disposed between the supply film roll  17  and the drive sprocket unit  22  whereby to pre-stretch the film a desired percentage to increase the yield of the supply roll  17  and also to weaken the film prior to feeding same under the straw supply bin  48  and into the trough former  29 . By stretching the film, the film is weakened whereby to facilitate the removal of the straw from the weakened film wrapper, as illustrated in FIGS. 15 and 16. By stretching the film its properties are changed and the film is artificially weakened. Because it is extremely difficult to fabricate thin films, this improvement in the machine resolves that problem of being unable to fabricate such thin films and to form a narrow roll thereof which has sufficient stability to be used with this type of machine. Another advantage of stretching the thin film is that the supply roll can be made wider and therefore have more stability and by stretching it, the film becomes narrower. The percentage of stretching and the desired characteristics of the film are adjusted in a speed control unit  131  which controls the speed of the driven roll  132  in the speed control driven roll unit  130 . It is also pointed out that it is extremely difficult to produce film rolls which are narrower than one inch. Accordingly, the film stretching can produce a wrapper having a film width of ¾ inch from a one inch supply roll. With the machine as thus modified, it is possible to stretch the film sufficiently to increase the yield by 10 to 15 percent and therefore lowering the cost. A wrapper speed controller  133  controls the speed of the film feed roll unit  22  and controls the speed of the machine in parts per minute.  
         [0065]    It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment of the invention as described herein, provided such modifications fall within the scope of the appended claims.