KR101288663B1 - Apparatus and Method for Shrink Wrapping Containers - Google Patents

Abstract

An apparatus for shrink wrapping a plurality of individually wrapped containers comprises a stacking station (100) for superimposing a pair of containers (10, 11) individually wrapped in a heat shrinkable film, a shrink tunnel (200), and a transfer device (120) for transferring a pair of superimposed containers (10, 11) from the stacking station (100) to the shrink tunnel (200). The transfer device (120) is adapted to engage and separate the pair of superimposed containers (10, 11) and to convey the pair of separated superimposed containers from the stacking station (100) into the shrink tunnel (200).

Description

Apparatus and Method for Shrink Wrapping Containers

TECHNICAL FIELD The present invention relates to a method and apparatus for shrink packaging of containers, and is particularly applied to shrink packaging of packs of smoking articles such as cigarettes.

It is known to shrinkwrap packs and other containers, for example with an outer film of polypropylene. During shrink packaging, the flow of packs of cigarettes individually wrapped with heat-shrinkable films is transferred through the shrink tunnel, where by hot convection and / or hot flat plates using hot air to shrink the film wrap around the packs The packs of cigarettes are heat-treated by conduction using. In order to increase the throughput rate of the pack through the shrink tunnel, individually packed packs are typically stacked in pairs and periodically transferred from the stacking or stacking station to the shrink tunnel.

In conventional shrinkwrap devices, a pair of packs of cigarette packs, in which reciprocating horizontal pushers are stacked vertically, are transferred from the stacking station to the shrink tunnel, where the pairs of packs are pushed against each other to form a continuous flow. The packs of cigarettes are thus overlapped and conveyed longitudinally through the shrinking tunnel into two adjacent rows, where the upper side of the lower row of cigarettes contacts the lower side of the upper row of cigarettes. The heat shrinkable film in contact with the inaccessible surfaces of these packs is disadvantageously exposed to little or no heat in the shrink tunnel. In order to avoid uneven shrinking of the film packaging and thereby forming wrinkles or wrinkles resulting in unsightly finished cigarette packs, heat is required to be applied to the top and bottom of each pack in the shrink tunnel.

U.S. Pat.No. 6,511,405 is located in the area between two overlapping armors, with an upper heating plate for applying heat to the upper facing front of the upper row of shells and a lower facing front of the upper shells of the upper row of shells. An apparatus is disclosed for manufacturing a shell having an improved outer package of an outer shape, including a shrinking station with a lower heating plate applied thereto. In this way the armors are transported through the contraction station over the lower heating plate, with the upper row of armors being lifted against the lower row of armors by the slopes in the area of the heating plates. The device disclosed in U.S. Patent No. US-B-6,511,405 provides access to the upward facing front of the lower row of armors, but by mechanically separating the two overlapping strings of the armors when the armors are transported to the retraction station Unshrinkable film packaging may be damaged. In addition, there is a significant risk that individual casings will be incorrectly positioned within the shrinking station and thus, casings with damaged casings and / or non-uniformly shrunk film wrappers will be formed.

It is an object of the present invention to provide an improved apparatus and method for shrink wrapping a plurality of individually packaged containers.

According to the present invention, there is provided an apparatus for shrink-packing a plurality of individually packaged containers, the apparatus for conveying a stacking station, a shrink tunnel, and a pair of overlapping containers individually packed with a heat shrinkable film from a stacking station to a shrink tunnel. It is characterized in that the conveying device is to engage and separate the overlapping container pairs, and also to transfer the separated container from the stacking station to the shrinking tunnel.

In use, separating the overlapping pairs of containers into a feeder rather than a slope or other hard repositioning means would allow the top or top and bottom or bottom of each container to access one or more heating devices provided in the shrink tunnel. As well as reducing or preventing the risk of damaging the containers and / or the unshrinkable film packaging of the containers as they are transferred to the shrink station.

Preferably the conveying device is adapted to apply a vacuum to a portion of the surface of at least one of the vessel pairs superimposed away from the shrink tunnel. More preferably the conveying device is adapted to apply a vacuum to the trailing side or face of the topmost container of the overlapping container pairs.

Preferably the conveying device has at least one suction plate or cup which engages with a portion of the surface of at least one of the container pairs overlapping away from the shrink tunnel. Preferably at least one suction plate or cup is mounted to a pusher mounted to move longitudinally with respect to the contraction tunnel. Preferably the pusher is mounted to the carriage on the cam track.

Preferably the shrink tunnel has at least one heating plate for applying heat to the film packaging of the separate containers. More preferably the contraction tunnel has an inner heating plate mounted between the separated vessels to heat the inward facing surfaces of the separated vessels. More preferably, the contraction tunnel is spaced apart from each other in order to apply heat to the outward surfaces of the separated vessels and the inner heating plate mounted between the separated vessels to heat the opposing inward sides of the separated vessels. Parallel outer heating plate.

Preferably the inner heating plate is fixed in order to reduce the friction between the separated vessels and the shrinking tunnel, and the outer heating plate is preferably adapted to move in sequence with the movement of the separated vessels.

The contraction tunnel may advantageously further comprise an inner heating plate and a second pair of opposing spaced parallel heating plates that are generally perpendicular to the outer heating plate pair to heat the corresponding additional surfaces of the separate vessels. In the case where a second pair of heating plates are provided, the second pair of opposing, spaced parallel heating plates may also be adapted to move in sequence with the movement of the separate vessel to reduce friction.

Any known suitable heating plate can be used in the shrink tunnel of the device of the invention, for example a heating plate heated by electrical resistance can be used. Furthermore, if desired, the apparatus of the present invention may further comprise means for supplying hot air to the shrinking tunnel in use to shrink the film packaging of the separate containers in place of or in addition to the one or more heating plates.

In a preferred embodiment of the apparatus of the present invention, the conveying device uses a suction unit to vertically engage the uppermost container by applying negative pressure applied to the rear side or the surface of the uppermost container of the overlapping container pairs formed in the vertical stacking station. Lift the container pairs by lifting them. If the containers to be shrink wrapped are packs of cigarettes, a vacuum between about 0.6 bar and about 1 bar is preferably applied to the top layer pack by the transfer device to separate the packs. The suction unit of the transfer device is vacuum in use. May be provided with, for example, a suction plate comprising a plurality of holes or one or more suction cups.

The suction unit is preferably mounted on a horizontal pusher, which in turn is mounted to the carriage on a fixed cam track. In use, when the carriage and the pusher move towards the contraction tunnel, the uppermost container is lifted vertically with respect to the lowermost container of the pair of packs that are engaged by the suction plates and overlapped. At the same time, the bottommost container is collected by a separate hinged finger mounted to the carriage as is known and is linearly conveyed at the same height towards the shrinking tunnel through further movement of the carriage and the pusher. The conveying device may alternatively engage the lowest vessel of the overlapping vessel pair using a negative pressure applied using a suction unit.

In order to obtain a continuous process, in a preferred embodiment of the apparatus of the present invention, applying a negative or reduced pressure to the rear side or face of the top layer container involves the overlap of the container pairs at the lamination station. The first container wrapped with a heat shrinkable film to form the overlapping container pairs is preferably lifted upwards by a predetermined height at the stacking station by a reciprocating vertical pusher, which is held in place in a known manner, The pusher returns to its initial position. The vertical pusher then lifts the second container packaged with the heat shrinkable film up to the same predetermined height at the lamination station, and at the bottom or bottom and in position of the first container supported on or above the second container. maintain. In a preferred embodiment of the device the engagement and separation of the overlapped container pair thus formed by the conveying device is such that during the time it takes for the vertical pusher to return to its original position to collect the container to form the first container of the subsequent stacked container pairs. This happens immediately after the containers overlap.

Typically, medium and high speed shrink wrap machines for packs of cigarettes operate at processing rates between 400 and 600 packs per minute. Thus, when a preferred embodiment of the device of the invention is used for shrink packaging of packs of cigarettes, the horizontal pusher and the carriage of the conveying device can be operated at about half of this speed, for example.

In order to facilitate the clean transfer of the pair of containers superimposed by the conveying device from the stacking station to the shrinking tunnel, in a preferred embodiment of the present invention the conveying device is also provided with a supply of compressed air to the suction unit into the shrinking tunnel. Blow out the container or containers.

In the shrinking tunnel, preferably at least the top of the bottommost container and the opposite bottom surface of the topmost container of the pair of separate and overlapping containers are heat treated with a heating device. Preferably the heating device supplies heat through at least one central heating plate located between the separated and overlapping pairs of vessels. More preferably, the heating device supplies heat through at least one fixed horizontal heating plate located between the separated and overlapping pairs of vessels, which also function as a support or directional plate for at least one of the vessels. The heating device can be any suitable known type, for example a plate heated by electrical resistance.

Preferably the contraction tunnel further comprises heating plates moving in sequence in separate vessels, ie vertically spaced parallel upper and lower heating plates which respectively heat the top surface of the top vessel and the bottom of the bottom vessel, respectively. Interlock up and down with the movement of the vessels directly below or above the field. This advantageously reduces the friction that can occur if the vessels are pushed through the shrinking tunnel with the static heating plate. The contraction tunnel of the preferred embodiment of the apparatus of the invention may further comprise side horizontally spaced side, side heating plates perpendicular to the upper and lower heating plates, which are separate and overlapping vessels for heating the sides of the vessels. Move in pairs on the field.

The height of the stacking station of the preferred embodiment of the inventive device is preferably increased by about one height of the container relative to the conventional stacking station by approximately three containers tall. Preferably the apparatus of the present invention is in use a pre-sealing mounted at the bottom of the lamination station for point sealing the opposing folded ends of the unshrinkable film packaging around the lowest of the three containers therein. (pre-sealing) unit is further provided. The preliminary sealing unit preferably comprises a pair of opposing reciprocating pneumatic cylinders mounted on opposite sides of the lamination station, which are heated with hot air in use. When the apparatus of the present invention is used to shrink wrap cigarette packs, the pneumatic cylinders are preferably positioned to spot heat two points on opposite sides of the bottom pack, wherein the heat shrinkable film is conventionally folded around the pack. Due to the way the thickness of the five films is folded.

Preferably the device of the present invention further comprises a choke detection device mounted to the lamination station. In a preferred embodiment, the choke detection device has a pair of opposing spring loaded fingers which are hinged and mounted 90 degrees from the side or exit of the top of the lamination station. In use, when an additional container is accidentally inserted into the lamination station, a spring loaded finger portion pivots upward with respect to the sides of the lamination station to generate a signal to stop the device by the sensor. In addition to detecting additional containers in the stacking station that can freeze or freeze the device, the spring loaded finger portion also advantageously bouncing the individually packaged containers as they are fed to the stacking station. Decrease.

In a preferred embodiment of the present invention, one of the stacking stations of the device of the present invention is hinged to the rest of the device so that the inner stacking station can be easily accessed, for example, to remove additional containers accidentally inserted.

According to the present invention, there is also provided a method of shrink wrapping a plurality of individually packaged containers, which method comprises stacking at least two containers individually wrapped with a heat shrinkable film in a lamination station to obtain a pair of overlapped containers. And separating the overlapping container pair by applying a vacuum to at least one of the pair of overlapping containers; And transferring the separated containers to a shrink tunnel.

Preferably the method of the present invention comprises applying a vacuum to the rear side or face of the topmost container of the overlapping container pair. The method of the present invention preferably has a vacuum between about 0.6 bar and about 1 bar when the containers to be shrink wrapped are bags.

Preferably the method further comprises the step of applying heat to opposite inward faces of the separated vessels in the contraction tunnel through a heating plate mounted between the separated vessels.

The apparatus and method according to the present invention will be described in more detail below using an embodiment with reference to the accompanying drawings.

1 shows a device of the invention.

1 shows a device according to the invention, comprising a stacking station 100 comprising a vertical stack of three individually packed packs of cigarettes 10, 11, 12. The upper cigarette pack 10 is lifted and separated from the lower cigarette pack 11 by applying a vacuum through at least one suction plate 110 or cup integrated into the horizontal pusher 120. The stacked upper and lower cigarette packs 10 and 11 are pushed forward by the horizontal pusher 120 into the longitudinal shrinking tunnel 200 having the central heating plate 210. Arrow 98 represents the upward movement of the cigarette pack 10 at the top. Arrow 99 indicates the movement of the upper and lower cigarette packs 10 and 11 downstream, ie the horizontal movement towards the contraction tunnel 200.

The method and apparatus according to the invention are particularly applicable to the manufacture of smoking articles, such as packs or cigarettes, in particular to the manufacture of hinged lid packs with rounded and / or chamfered corners.

Existing conventional shrink wrapping devices with stacking stations and shrink tunnels can advantageously be easily improved by introducing a suitable conveying device for producing the device according to the invention.

Claims (11)

An apparatus for shrink wrapping a plurality of individually packaged containers, A lamination station 100 for overlapping a pair of containers 10, 11 individually wrapped with a heat shrinkable film; Shrink tunnel 200; And In the apparatus for shrink-packing a container having a; transfer device 120 for transferring a pair of containers (10, 11) superimposed in the shrinking tunnel 200 in the stacking station 100, The transfer device 120 is configured to engage and separate the overlapping pairs of containers 10 and 11 and transfer the separated and overlapped pairs of containers from the stacking station 100 to the shrinking tunnel 200. 120 is adapted to apply a vacuum to the upper surface of the container of the pair of containers (10, 11), so that the upper container can be lifted upward with respect to the lower container, the lower together with the upper shell The container for shrink packaging of the container, characterized in that the container is adapted to be pushed transversely toward the contraction tunnel (200). delete 2. The conveying device (120) of claim 1, wherein the conveying device (120) comprises at least one suction plate (110) or cup for engaging the surface of at least one of the pairs of containers (10, 11) overlapping away from the shrinking tunnel (200). Characterized in that the device for shrink wrapping of the container. delete delete delete 4. Container according to claim 1 or 3, characterized in that the shrinking tunnel (200) comprises at least one heating plate (210) for applying heat to the film packaging of the separate containers (10, 11). A device for shrink wrapping. delete delete delete As a method of shrink wrapping a plurality of individually packaged containers (10, 11, 12), Stacking at least two containers (10, 11, 12) individually packaged with a heat shrinkable film in a lamination station (100) to obtain a pair of containers (10, 11) overlapped; Applying a vacuum to at least one of the overlapping container (10, 11) pairs to separate the overlapping container pairs (10, 11); And In the method of shrink wrapping and packaging, comprising; transferring the separated and overlapping pair of containers (10, 11) to the shrink tunnel (200), The step of applying the vacuum is to apply a vacuum to the upper surface of the container (10, 11), so that the upper container can be lifted upward with respect to the lower container, Together with the bottom container is pushed transversely toward the contraction tunnel 200 to shrink the packaging method.

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