Vertical form, fill and seal machine for making recloseable bags

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• means for storing and supplying a continuous, plastic, cap strip,
• a generally vertical fill tube assembly downstream of said means for storing and supplying the continuous plastic film and said means for storing and supplying the cap strip, said fill tube assembly including a vertical fill tube of substantially constant oval horizontal cross section with a minor diameter of at least two inches and a major diameter at least about two inches greater than said minor diameter and with concentric oval interior and exterior surfaces having generally planar sides and curved ends, said fill tube assembly further including means for forming said film around the exterior of said fill tube with edges of said film meeting at one end of the major diameter of said fill tube,
• feeding means including a film drive roll upstream of the fill tube and a pair of film pull belts adjacent the fill tube for feeding the cap strip and plastic film along the length of said fill tube in bag length increments with the edges of the continuous film in overlapping relationship with edges of the cap strip at one of the curved ends of said fill tube,
• vertical sealing means for sealing the edges of the continuous film to the edges of the cap strip to form a flexible, plastic tube,
• each belt of said pair of film pull belts being mounted on a respective opposing side of the vertical fill tube and cooperating with said fill tube for feeding the plastic film,
• horizontal sealing and severing means downstream of said fill tube for forming horizontal seals across the flexible plastic tube and for severing the plastic tube between the horizontal seals, said horizontal sealing and severing means including opposing clamping elements which reciprocate in a plane substantially transverse to the vertical axis of said fill tube with the plastic tube located between said clamping elements which reciprocate toward each other to clamp the plastic tube therebetween along a line parallel with the major diameter of said fill tube during horizontal sealing and severing of said plastic tube, and
• tensioning means for horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said horizontal seals.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• means for storing and supplying a continuous, plastic, zippered cap strip,
• a generally vertical tube assembly downstream of said means for storing and supplying the continuous plastic film and said means for storing and supplying the zippered cap strip, said tube assembly including an elongate oval fill tube of substantially constant oval horizontal cross section with a minor diameter of at least two inches and a major diameter at least about two inches greater than said minor diameter and with concentric oval interior and exterior surfaces, said tube assembly further including means for forming said film around the exterior of said oval fill tube with edges of said film extending from one end of the major diameter of said oval fill tube and means for guiding the zippered cap strip with the edges of the film in overlapping relationship with edges of the zippered cap strip along one end of the major diameter of said fill tube,
• feeding means including a film drive roll upstream of the fill tube and a pair of film pull belts adjacent the fill tube for feeding the zippered cap strip and plastic film along the length of said oval fill tube in bag length increments,
• vertical sealing means for sealing the edges of the continuous film to the edges of the zippered cap strip to form a length of flexible, plastic tube, and
• horizontal sealing and severing means downstream of said oval fill tube arranged to form first and second horizontal seals in the plastic film generally parallel to said fill tube major axis and for severing the plastic tube between the first and second horizontal seals, the first horizontal seal defining the downstream edge of a bag about to be filled with product and the second horizontal seal defining the upstream edge of a bag which has already received product.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• a generally vertical fill tube assembly downstream of said means for storing and supplying the continuous plastic film, said fill tube assembly including a vertical fill tube of substantially constant oval horizontal cross section with a minor diameter of at least two inches and a major diameter at least about two inches greater than said minor diameter and with concentric oval interior and exterior surfaces having generally planar sides and curved ends, said fill tube assembly further including means for forming said film around the exterior of said fill tube with edges of said film meeting at one end of the major diameter of said fill tube,
• feeding means for feeding the plastic film along the length of said fill tube in bag length increments with the edges of the continuous film in overlapping relationship at one of the curved ends of said fill tube,
• vertical sealing means for sealing the edges of the continuous film to form a flexible, plastic tube,
• horizontal sealing and severing means downstream of said fill tube for forming horizontal seals across the flexible plastic tube and for severing the plastic tube between the horizontal seals, said horizontal sealing and severing means including opposing clamping elements which reciprocate in a plane substantially transverse to the vertical axis of said fill tube with the plastic tube located between said clamping elements which reciprocate relative to each other to clamp the plastic tube therebetween on a line parallel with the major diameter of said fill tube, and
• means for horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said horizontal seals.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film including a film supply drive roll,
• means for storing and supplying a continuous, plastic, cap strip,
• a generally vertical tube assembly downstream of said means for storing and supplying the continuous plastic film and said means for storing and supplying a cap strip, said tube assembly including a tube of oval horizontal cross section with a minor diameter of at least two inches and a major diameter of at least four inches and means for forming said film around said tube with the edges of said film meeting at one end of the major diameter of said tube,
• feeding and vertical sealing means for feeding the cap strip and plastic film along the length of said tube in bag length increments with the edges of the continuous film in overlapping relationship with the edges of the cap strip, and for sealing the edges of the continuous film to the edges of the cap strip to form a length of flexible, plastic tube,
• said feeding and vertical sealing means including a pair of film pull belts with one mounted on each side of the vertical fill tube and cooperating with said fill tube for feeding the plastic film,
• horizontal sealing and severing means downstream of said tube for forming first and second horizontal seals across the flexible plastic tube and for severing the horizontally sealed plastic tube between the first and second horizontal seals, the first horizontal seal defining the downstream edge of a bag about to be filled with product and the second horizontal seal defining the upstream edge of a bag which has already received product, and
• tensioning means for horizontally elongating the flexible, plastic tube transverse to its length prior to formation of said first horizontal seal.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film and zippered cap strip into separate product-filled, reclosable, sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• means for storing and supplying the continuous, plastic, zippered cap strip,
• a generally vertical fill tube assembly including a forming collar and a vertically elongated ovaloid cross-section vertical fill tube downstream of the means for storing and supplying the continuous film and zippered cap strip, said forming collar causing the continuous film to wrap around the exterior of said fill tube with edges of said film meeting at one end of a major diameter of said fill tube, at least a substantial portion of the length of said vertical fill tube having a substantially constant horizontal cross section and concentric interior and exterior surfaces,
• feeding means for feeding the continuous zippered cap strip and plastic film along the length of the vertical fill tube in bag length increments with the edges of the continuous film in overlapping relationship with the edges of the zippered cap strip,
• said feeding means including a pair of film pull belts with one mounted on each side of the vertical fill tube and cooperating with said fill tube for feeding the plastic film,
• vertical sealing means for sealing the edges of the continuous film to the edges of the continuous zippered cap strip to form a length of flexible, plastic tube, and
• horizontal sealing and severing means downstream of the vertical fill tube for forming at least one horizontal seal across the flexible plastic tube and for severing the plastic tube in the vicinity of said horizontal seal.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• means for storing and supplying a continuous, plastic, cap strip,
• a generally vertical fill tube assembly downstream of said means for storing and supplying the continuous plastic film and said means for storing and supplying the cap strip, said fill tube assembly including a vertical fill tube of substantially constant oblong horizontal cross section with a minor diameter of at least two inches and a major diameter at least about two inches greater than said minor diameter and with concentric interior and exterior surfaces having generally planar sides and curved end portions, said fill tube assembly further including means for forming said film around the exterior of said fill tube with edges of said film meeting at one end of the major diameter of said fill tube,
• feeding means for feeding the cap strip and plastic film along the length of said fill tube in bag length increments with the edges of the continuous film in overlapping relationship with edges of the cap strip at one end of said fill tube,
• said feeding means including a pair of film pull belts with one mounted on each side of the vertical fill tube and cooperating with said fill tube for feeding the plastic film,
• vertical sealing means for sealing the edges of the continuous film to the edges of the cap strip to form a flexible, plastic tube, and
• horizontal sealing and severing means downstream of said fill tube for forming horizontal seals across the flexible plastic tube and severing the plastic tube between the horizontal seals.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• means for storing and supplying a continuous, plastic, zippered cap strip,
• a generally vertical tube assembly downstream of said means for storing and supplying the continuous plastic film and said means for storing and supplying the zippered cap strip, said tube assembly including a vertically elongated ovaloid fill tube of substantially constant horizontal cross section with concentric interior and exterior surfaces, said tube assembly further including means for forming said film around the exterior of said fill tube with edges of said film extending from one end of the major diameter of said fill tube and means for guiding the zippered cap strip with the edges of the film in overlapping relationship with edges of the zippered cap strip along one end of the major diameter of said fill tube,
• feeding means for feeding the zippered cap strip and plastic film along the length of said oval fill tube in bag length increments,
• said feeding means including a pair of film pull belts with one mounted on each side of the vertical fill tube and cooperating with said fill tube for feeding the plastic film,
• vertical sealing means for sealing the edges of the continuous film to the edges of the zippered cap strip to form a length of flexible, plastic tube, and
• horizontal sealing and severing means downstream of said fill tube for sealing and severing the plastic tube.

A vertical, form, fill, and seal apparatus of the type that operates in conjunction with a product supply apparatus providing product in discrete quantities and that forms a continuous, heat sealable plastic film into separate product-filled sealed bags comprising:

• means for storing and supplying the continuous plastic film,
• a generally vertical fill tube assembly downstream of said means for storing and supplying the continuous plastic film, said fill tube assembly including a vertical fill tube of substantially ovaloid constant horizontal cross section with a minor diameter of at least two inches and a major diameter at least about two inches greater than said minor diameter and with concentric interior and exterior surfaces, said fill tube assembly further including means for forming said film around the exterior of said fill tube with edges of said film meeting at one end of the major diameter of said fill tube,
• feeding means for feeding the plastic film along the length of said fill tube in bag length increments with the edges of the continuous film in overlapping relationship at one of the curved ends of said fill tube,
• said feeding means including a pair of film pull belts with one mounted on each side of the vertical fill tube and cooperating with said fill tube for feeding the plastic film,
• vertical sealing means for sealing the edges of the continuous film to form a flexible, plastic tube, and horizontal sealing and severing means downstream of said fill tube for forming horizontal seals across the flexible plastic tube and for severing the plastic tube.