GB2291634A

GB2291634A - Packaging in interconnected bags

Info

Publication number: GB2291634A
Application number: GB9413726A
Authority: GB
Inventors: Colin Ching
Original assignee: Sidlaw Flexible Packaging Ltd
Current assignee: Amcor Flexibles UK Ltd
Priority date: 1994-07-07
Filing date: 1994-07-07
Publication date: 1996-01-31
Also published as: GB9413726D0

Abstract

Packaging apparatus comprises a feeder 2 for feeding a continuous tubular web to a filling station, the web 3 having spaced apart transverse slits 4 in one face to form the mouths of respect bags; a blower for directing a stream of air through an outlet 10 into the slit 4 to open the bag; means for filling the bag and closing means 11 at a closing station for sealing the mouth of the filled bag and severing it from the web. The air outlet 10 is between a pair of nip rollers 2 of the feeder and an adjustably-mounted plate 9. A pair of guide fingers 8 are pivotable into the opened bag mouth to guide manual insertion of material such as a catalogue or magazine. The bed 7 of the apparatus may be inclined and provided with non-driven conveyor means such as rollers or a belt. The web 3 is advanced stepwise and has printed identification strips 5 detected by a photosensor 6. <IMAGE>

Description

PACKAGING APPARATUS AND METHOD The present invention relates to packaging apparatus and a method for packaging material such as printed documents into a sealed bag.

Increasingly, printed material such as catalogues and magazines is supplied inside a sealed protective bag of transparent thermoplastic material such as polythene. A number of devices have been proposed to seal material inside bags but they are generally cumbersome and awkward to operate.

The present invention overcome these and other problems of known devices in this field.

According to the invention there is provided packaging apparatus comprising: a feeder for feeding a continuous web to a filling station, the web having spaced apart transverse slits in one face; a blower for directing a stream of air through an outlet into the slit to open the bag; means for filling the bag and closing means at a closing station for sealing the opening of the filled bag and severing it from the web.

Preferably the web has a transverse seal located adjacent to each transverse slit.

Preferably, the feeder comprises a pair of nip rollers operable by a motor in a stepwise manner. Conveniently, the apparatus further comprises a sensor which senses a marker on the web and operates the motor to feed a length of continous web to the filling station so that the slit which constitutes the bag opening is adjacent the outlet of the blower. The sensor may also operate to initiate the filling and sealing operations.

Preferably, the sensor is a photosensor which senses a printed strip marked on the web.

Preferably, the blower is adjustable to vary the air flow which opens the bag. In a preferred arrangement the air is blown through an outlet comprising the space defined between the nip rollers and a plate. The distance between the plate and the rollers and the attitude of the plate can be varied by moving the plate to adjust the air flow as required.

Advantageously, a pair of guide fingers are provided at the filling station.

In operation, ends of the fingers move into the opening of the bag to form a funnel through which the filling material can be inserted into the bag.

The guide fingers may be spring loaded to ensure that the bag is wide open prior to filling. The provision of guide fingers makes the filling operation simple.

The open bag can be filled manually or automatically depending on the particular application.

The apparatus of the invention represents a significant advance from known techniques in which a continuous web of sheet, folded off centre, is divided by spaced apart transverse seals into a series of bags in which the slit opening is on one side of the web, that is, parallel to the longitudinal axis of the web. In this known technique the bags are filled from the side, that is, in a direction transverse to the longitudinal axis of the web. A serious disadvantage with this technique is that any tension along the longitudinal axis of the web acts to close the bag opening, making the filling operation difficult.

The apparatus of the invention does not suffer from this problem because the filling material is inserted in a direction along the longitudinal axis of the web. This means that the effect of any tension along the longitudinal axis of the web is to widen the bag opening.

Advantageously, the filled bag travels along an inclined bed to the closing station. With this arrangement the filled bag moves to the closing station under the assistance of gravity.

The filled bag may be sealed by forming transverse seal on either side of the slit and severing the web between the seals. One of the seals closes the filled bag and the other seal forms the bottom of the next bag.

Preferably however, when the web has a transverse seal located adjacent to each transverse slit, the filled bag is sealed by forming a transverse seal on one side of the slit and severing the web between the seals. The sealing closes the filled bag and severs it from the rest of the web.

With a conventional thermoplastic web, sealing can be effected by an element heated electrically.

Preferably, the position of the closing station relative to the filling station is adjustable. This allows the apparatus to be used to fill and seal bags of different lengths. Conveniently, the closing means is mounted on rails which run on each side of the web. This arrangement makes it easy to move the closing means along the rail and fix it in a position to suit a given bag length.

Preferably the sealing operation takes place at the same time as the filling operation for the next bag.

In a further aspect the invention provides method of making a sealed bag containing filling material comprising: feeding a length of continuous tubular web having spaced apart transverse slits on one face, and preferably a transverse seal located adjacent to each transverse slit, to a filling station to position the slit adjacent a blower; blowing a stream of air into the slit to open the bag; filling the bag with the filler material; moving the filled bag to a closing station; sealing the bag opening and severing the sealed bag from the web.

The method is repeated to produce the number of bags required.

Advantageously, the method further comprises inserting guide fingers into the bag opening to provide a funnel for inserting the filler material into the bag opening during the filling operation.

Preferably, the sealing operation is carried out at the same time as the filling operation of the next bag.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which.

Figure 1 is a perspective view of packaging apparatus of the invention; Figure 2 is a plan view of packaging apparatus of the invention; and Figure 3 is a side view of the apparatus of Figure 2.

In one embodiment, packaging apparatus of the invention comprises a compact unit 1 comprising a first portion including a pair of nip rollers 2, and a stepper motor (not shown) for driving the rollers. A continuous web 3 of polythene sheet, folded off centre, is stored under the nip rollers and fed through the rollers in use. The web includes spaced apart transverse slits 4 on one face and printed identification strips 5 at set intervals along the web. In use, the strips 5 are detected by a photosensor 6 and serve to ensure proper alignment of the web in the filling station.

Transverse seals 4a are located adjacent to each slit 4 and eventually from the bottom side of a bag.

The filling station comprises an inclined bed 7 and a pair of guide fingers 8 which are spring loaded to bias them outwardly.

As shown in figure 1, a plate 9 is provided adjacent the nip rollers to define an air outlet 10. Behind the plate is an air pump or blower (not shown) which blows a stream of air between the rollers and the plate. By adjusting the distance between the plate and rollers and the attitude of the plate, the flow of the air stream can be varied.

The apparatus further comprises a closing station including an electric heating element 11 for heat-sealing the faces of the web together. The closing station also includes a cutter for severing the web.

As shown, the closing station can be moved relative to the filling station along rails 12 and locked in position by fasteners 13. The apparatus can therefore be used for a variety of bag lengths.

Finally, the closing station includes a chute 14 down which packaged material can fall.

In use, the apparatus operates as follows: A length of web is fed into the filling station by the nip rollers 2 until the transverse slit 4 is adjacent the air outlet 10. The air pump blows a stream of air into the slit to open the bag.

The guide fingers 8 move into the opened slit of the bag to form a funnel and the filler material is inserted manually.

The nip rollers are then operated to advance the web such that a successive bag is fed to the filling station; the filled bag being fed under gravity to the closing station.

To assist movement of the filled bag, the bed of the machine between the filling and closing station may be defined as a moving bed, for example the bed may be a band conveyor or roller conveyor. The conveyor is preferably free running such that the weight of the filler material causes the filled bag to move under the assistance of gravity into the closing station. At the closing station the heating element 11 is brought into contact with the web and heated electrically. This forms a transverse heat seal in the web inside the slit which closes the filled bag and forms the bottom side of the bag.

The sealing and filling operations are carried out simultaneously.

In an alternative embodiment, when the web does not include a transverse seal adjacent to each transverse slit, the heating element is configured to produce a transverse seal simultaneously on either side of the web. One of the seals closes the filled bag and the other forms the bottom side of the next bag. The heat sealing may act to sever the web or a cutter can be provided to sever the web between the seals to sever the filled bag from the rest of the web.

It will be appreciated that the apparatus is simple, compact and provides a very convenient yet efficient method of packaging material in a sealed bag.

Claims

1. Packaging apparatus according to the invention there is provided packaging apparatus comprising: a feeder for feeding a continuous web to a filling station, the web having spaced apart transverse slits in one face; a blower for directing a stream of air through an outlet into the slit to open the bag; means for filling the bag and closing means at a closing station for sealing the opening of the filled bag and severing it from the web.

2. Apparatus according to claim l wherein the feeder comprises a pair of nip rollers located adjacent to the filling station, the rollers being driven in a step wise manner by a motor.

3. Apparatus according to claim 2 wherein the outlet for the blower comprises a space defined between the nip rollers and a plate.

4. Apparatus according to claim 3 wherein the plate is mounted such that the distance between the plate and the nip rollers, and the altitude of the plate can be varied in order to adjust the air flow through the outlet.

5. Apparatus according to any preceding claim wherein a pair of guide fingers are located at the filling station, the guide fingers having ends movable into the opening of a bag opened by said blower to form a funnel through which filling material can be inserted into the bag.

6. Apparatus according to claim 5 wherein the fingers are spring loaded to ensure that the bag is wide open prior to filling.

7. Apparatus according to any preceding claim wherein an inclined bed is located between the filling station and closing station along which filled bags are conveyed to the closing station.

8. Apparatus according to claim 7 wherein the inclined bed is a moving bed.

9. Apparatus according to claim 8 wherein the moving bed is a band or roller conveyor.

10. Apparatus according to claim 9 wherein the conveyor is free running such that the weight of the filling material causes the filled bag to move under the assistance of gravity to the closing station.

11. Apparatus according to any preceding claim wherein the filling and closing stations are spaced apart such that filling and closing operations may be performed simultaneously.

12. Packaging apparatus substantially as herein described with reference to and as illustrated in the accompanying drawings.

13. A method of making a sealed bag containing filling material comprising: feeding a length of continuous tubular web having spaced apart transverse slits on one face, and preferably a transverse seal located adjacent to each transverse slit, to a filling station to position the slit adjacent a blower; blowing a stream of air into the slit to open the bag; filling the bag with the filler material; moving the filled bag to a closing station; sealing the bag opening and severing the sealed bag from the web.

14. A method according to claim 13 including inserting guide fingers into the bag opening to provide a funnel for inserting the filling material.

15. A method of making a sealed bag containing filling material substantially as herein described with reference to the accompanying drawings.