Flexible package-forming machine for horizontal packaging and method of manufacturing flexible packages

Abstract

The present invention relates to a flexible package-forming machine for horizontal packaging and method of manufacturing flexible packages. The proposed forming machine consists of an unwinding unit (11), a perforating unit (12), a folding unit (14), a welding unit (16), and a cutting unit (17), wherein a compensating unit (13) is further included intercalated between the perforating unit (12) and the folding unit (14), linking a section with intermittent forward movement (S1) of the flexible band (1) where the flexible band moves in an intermittent manner and including the perforating unit, and a section with continuous forward movement (S2) where the flexible band moves in a continuous manner and including the folding unit, flexible band being accumulated in said compensating unit during the forward movement of the section with intermittent forward movement (S1) and the accumulation being reduced during breaks in the forward movement of the section with intermittent forward movement.

Claims

1. A flexible package-forming machine for horizontal packaging by folding and welding flexible band comprising, in this order with respect to a forward movement direction of the flexible band, at least: one unwinding unit for unwinding the flexible band in the forward movement direction; one perforating unit of the flexible band for perforating the flexible band in pre-established precise positions thereof; one folding unit of the flexible band configured for folding said flexible band along at least one folding line parallel to the forward movement direction, at least two portions arranged on opposite sides of said at least one folding line of one and the same face of the flexible band being arranged opposite one another; one welding unit of the folded flexible band configured for making welding lines at least in a direction transverse to the forward movement direction of the flexible band; one cutting unit for separating portions making up flexible packages; characterized in that: a movement compensating unit for compensating the movement of the flexible band intercalated between the perforating unit and the folding unit, said compensating unit linking a section with intermittent forward movement of the flexible band and a section with continuous forward movement of the flexible band, said compensating unit being provided with at least: one inlet roller in contact with the flexible band with an axis of rotation perpendicular to the forward movement direction and fixed with respect to the forming machine, one outlet roller in contact with the flexible band with an axis of rotation perpendicular to the forward movement direction and fixed with respect to the forming machine; at least one accumulator roller in contact with the flexible band between the inlet roller and the outlet roller in the forward movement direction, and with an axis of rotation perpendicular to the forward movement direction and movable with respect to the axes of rotation of the inlet roller and the outlet roller being kept perpendicular to the forward movement direction of the flexible band; said accumulator roller being provided with and/or connected to a tautening device provided for moving the accumulator roller away from the inlet roller and/or outlet roller, keeping the flexible band taut; the tautening device including: springs provided for moving the at least one accumulator roller away from the inlet roller and/or outlet roller, or a guiding system of the accumulator roller with a vertical component, the inlet roller, the outlet roller and the accumulator roller being horizontal rollers and the accumulator roller being at a lower height than the inlet roller and the outlet roller (23) during accumulation, causing the tautening of the flexible band by gravity; and the section with intermittent forward movement includes an intermittent drive unit configured for moving the flexible band in the forward movement direction in an intermittent manner, and wherein the section with continuous forward movement includes a continuous drive unit configured for moving the flexible band in the forward movement direction in a continuous manner.

2. The machine according to claim 1, wherein the guiding system of the accumulator roller includes cogwheels at the ends of the accumulator roller and cogged tracks.

3. The machine according to claim 1, wherein the perforating unit is a die-cutting unit.

4. The machine according to claim 3, wherein the die-cutting unit is arranged opposite a horizontal segment of the flexible band.

5. The machine according to claim 4, wherein at least the perforating unit, the compensating unit and the folding unit are supported on a common frame defining a compact forming module, and wherein the compensating unit and the folding unit are arranged above the horizontal segment of the flexible band opposite the die-cutting unit.

6. The machine according to claim 1, wherein at least the perforating unit, the compensating unit and the folding unit are supported on a common frame defining a compact forming module.

7. The machine according to claim 1, wherein there is intercalated between the folding unit and the welding unit an additional movement compensating unit for compensating the movement of the flexible band, separating the section with continuous forward movement from an additional section with intermittent forward movement of the flexible band, said additional compensating unit being provided with at least: one inlet roller in contact with the folded flexible band with an axis of rotation perpendicular to the forward movement direction, one outlet roller in contact with the folded flexible band with an axis of rotation perpendicular to the forward movement direction; at least one accumulator roller in contact with the folded flexible band between the inlet roller and outlet roller in the forward movement direction, and with an axis of rotation perpendicular to the forward movement direction; the at least one accumulator roller being movable with respect to the inlet roller and outlet roller, keeping the axis of rotation thereof perpendicular to the forward movement direction of the flexible band, and said accumulator roller being provided with and/or connected to a tautening device provided for moving the accumulator roller away from the inlet roller and/or outlet roller, keeping the flexible band taut; and wherein the additional section with intermittent forward movement includes an additional intermittent drive unit.

8. The machine according to claim 1, wherein the inlet roller of the compensating unit is also the intermittent drive unit of the section with intermittent forward movement of the flexible band.

9. A method for forming flexible packages for horizontal packaging by means of folding and welding a flexible band comprising the steps of: feeding a flexible band in the forward movement direction to the flexible package-forming machine by means of an unwinding unit for unwinding the flexible band; driving said flexible band in the forward movement direction; perforating said flexible band in pre-established precise positions by means of a perforating unit of the flexible band, obtaining a perforated flexible band; folding, by means of a folding unit, said flexible band along at least one folding line parallel to the forward movement direction, at least two portions arranged on opposite sides of said at least one folding line of one and the same face of the flexible band being arranged opposite one another, obtaining a folded flexible band; welding, by means of a welding unit arranged after the folding unit in the forward movement direction, the folded flexible band along at least welding lines transverse to the forward movement direction of the flexible band; cutting the folded and welded flexible band for obtaining individual flexible packages; characterized in that the method also includes: driving with an intermittent movement said flexible band in the forward movement direction through a section with intermittent forward movement by means of an intermittent drive unit; feeding in the forward movement direction and in an intermittent manner the perforated flexible band obtained from said perforating unit to a compensating unit, cyclic accumulation of the perforated flexible band taking place in said compensating unit during the movement of the flexible band in the section with intermittent forward movement; driving with a continuous movement said perforated flexible band in the forward movement direction through a section with continuous forward movement after the compensating unit in the forward movement direction by means of a continuous drive unit, cyclic deaccumulation of the perforated flexible band taking place in said compensating unit during breaks in the intermittent movement of the flexible band in the section with intermittent forward movement; wherein the steps of feeding the forming machine and perforating the flexible band are performed on the section with intermittent forward movement of the flexible band; and wherein the step of folding the flexible band is performed on the section with continuous forward movement of the flexible band.

10. The method according to claim 9, wherein after folding the flexible band produced by the folding unit, the followings is performed feeding in the forward movement direction and in a continuous manner the folded flexible band obtained from said folding unit to an additional compensating unit; driving with an intermittent movement said folded flexible band in the forward movement direction through an additional section with intermittent forward movement after the additional compensating unit in the forward movement direction by means of an additional intermittent drive unit, cyclic accumulation of the folded flexible band taking place in said additional compensating unit during breaks in the intermittent movement of the flexible band in the section with forward movement, and cyclic deaccumulation of the folded flexible band taking place in said additional compensating unit during the movement of the flexible band in the additional section with intermittent forward movement.

11. The method according to claim 10, wherein the step of welding the folded flexible band by means of a welding unit are performed on the additional section with intermittent forward movement of the flexible band during breaks in the intermittent movement of the flexible band.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing and other advantages and features will be more clearly understood based on the following detailed description of an embodiment in reference to the attached drawings which must be interpreted in an illustrative and non-limiting manner, in which:

(2) FIG. 1 shows a schematic side view of the proposed forming machine according to a preferred embodiment including a compensating unit located between the perforating unit and the folding unit, and further including an additional compensating unit between the folding unit and the welding unit;

(3) FIG. 2 shows a perspective view of a compact forming module integrating, in one and the same frame and in superposed levels, a perforating unit, a compensating unit and a folding unit.

DETAILED DESCRIPTION OF AN EMBODIMENT

(4) The attached drawings show illustrative but non-limiting embodiments of the present invention.

(5) FIG. 1 schematically shows an embodiment of the proposed forming machine including the following elements in the following order: an unwinding unit 11 feeding a flexible band 1 to the forming machine. Said unwinding unit will consist of a reel of flexible band supported on a shaft which will allow the rotation thereof. Said flexible band will preferably be made of a plastic material and can be printed on one or both faces, or can be passed through a printing machine before being fed to the forming machine.

(6) The flexible band moves through the forming machine in a forward movement direction DA going through, successively, a perforating unit 12, an intermittent drive unit 31, a compensating unit 13, a folding unit 14, a continuous drive unit 32, an additional compensating unit 15, a welding unit 16, an additional intermittent drive unit 33, and finally a cutting unit 17.

(7) The segment of flexible band 1 comprised between the unwinding unit 11 and the intermittent drive unit 31 will form a section with intermittent forward movement S1 in which the flexible band 1 will move intermittently driven by said intermittent drive unit 31, taking breaks, said breaks allowing easy and precise actuation of the perforating unit 12 to make the relevant perforations on the flexible band 1.

(8) The segment of flexible band 1 comprised between the compensating unit 13 and the continuous drive unit 32 will form a section with continuous forward movement S2 in which the flexible band 1 will move continuously driven by said continuous drive unit 32, allowing a constant and homogeneous folding of the flexible band 1 by means of the folding unit 14.

(9) The segment of flexible band 1 after the additional compensating unit 15 will form an additional section with intermittent forward movement S3 in which the flexible band 1 will move intermittently driven by said intermittent drive unit 31, taking breaks, said breaks allowing easy and precise actuation of the welding unit 16 and the cutting unit 17.

(10) According to the present embodiment, the perforating unit 12 is moved above a horizontal segment of the flexible band 1, and consists of a die-cutting unit, thereby allowing die-cutting the flexible band from above, eliminating the die-cut residues below said flexible band 1. It is furthermore proposed that the die-cutting unit consist of multiple dies supported on bridges perpendicular to the forward movement direction DA, said bridges being movable in the forward movement direction DA for a correct regulation and calibration of the perforating unit 12, and each die being movable along the corresponding supporting bridge, which also allows regulating the position thereof transverse to the flexible band 1. These two options of movement allow correctly adapting and positioning each die during a step of calibrating the forming machine. This embodiment is shown in FIG. 2.

(11) The intermittent drive unit consists of a cylinder operated by means of a motor or a servomotor configured for causing the rotation of the cylinder in an intermittent manner. At least one pressure cylinder has been provided opposite said cylinder and the flexible band which is pressed against the mentioned operated cylinder and driven by the rotation of the cylinder in an intermittent manner is made to pass between both.

(12) The compensating unit 13 consists of an inlet roller 21, which in this case is also the mentioned operated cylinder of the intermittent drive unit 31, an outlet roller 23, and between both an accumulator roller 22 located at a lower height than the other two rollers. The three rollers are parallel to one another and perpendicular to the forward movement direction DA of the flexible band 1.

(13) The weight of said accumulator roller 22 keeps the flexible band 1 taut, and a guiding system 24 allows the vertical movement of the accumulator roller 22, making the distance thereof with respect to the inlet roller 21 and the outlet roller 22 smaller or larger depending on the amount of flexible band fed to and extracted from said compensating unit 13.

(14) After the compensating unit, the flexible band 1 goes through the folding unit which in this example consists of a forming triangle provided with two converging edges around which the flexible hand runs in the forward movement direction, the band being folded, obtaining as a result a flexible band 1 folded along a longitudinal folding line parallel to the side edges of the flexible band 1 and parallel to the forward movement direction DA, said folding line preferably being in the center of the flexible band 1. The folded flexible band will therefore consist of two halves arranged opposite one another and joined at their lower end by the folding line and arranged opposite one another but not joined at their upper end where the two side edges of the flexible band will coincide.

(15) According to a preferred embodiment, the folding unit makes at least three folding lines parallel to one another conferring a W-shaped section to the folded flexible band 1. This allows obtaining flexible packages capable of staying upright.

(16) The continuous drive unit 32 and the additional compensating unit 15 will be of a nature similar to that described in relation to the intermittent drive unit 31 and to the compensating unit 13, with the exception that they are located with their axes in vertical, the continuous drive unit being configured for driving the flexible band 1 at a constant speed. Furthermore, gravity in the additional compensating unit 15 will be replaced with an elastic force supplied, for example, by means of springs or pneumatic pistons.

(17) The welding unit 16 will join the two opposite halves of the flexible band 1 to one another along welding lines 2, at least one of them being transverse to the forward movement direction DA, thereby forming bags or pouches in the folded and welded flexible band. The weld can be produced by pressing hot clamps on opposite faces of the folded flexible band 1, faces.

(18) The intermittent drive unit 33, which is the same as the one described above, will then drive the flexible band 1 in an intermittent manner and subsequently feed it to the cutting unit 17 which will make cuts that will separate the flexible packages, for example, by means of using blades.

(19) FIG. 2 shows a more detailed embodiment in which the perforating unit 12, the compensating unit 13 and the folding unit 14 are supported on a shared frame forming a compact forming module in which the compensating unit 13 and the folding unit 14 move above a perforating unit 12 arranged opposite a horizontal segment of the flexible band 1.

(20) It will be understood that the different parts making up the invention described in one embodiment can be freely combined with parts described in other different embodiments even though said combination has not been explicitly described, provided that the combination does not affect the invention.