WO1997003877A1

WO1997003877A1 - A method for use in packing items in a number of packing material webs and an apparatus for use in the method

Info

Publication number: WO1997003877A1
Application number: PCT/DK1996/000324
Authority: WO
Inventors: Soeren Gram
Original assignee: Gram A/S
Priority date: 1995-07-17
Filing date: 1996-07-17
Publication date: 1997-02-06
Also published as: DK171581B1; AU6513496A; DK83795A

Abstract

In the production of packings in a packing material web (23) provided with a cold-sealing adhesive, it is possible to store storage rolls (26) in a separate storage station and at the same time have packing lines in a packing apparatus positioned as close together as the width of the packed items permits. This is possible as a packing web (23) is conveyed to a packing line at a substantially vertical orientation when passing between vertically oriented guides (24). The web (23) passes around a turning roller (31), which functions simultaneously as a folding roller so that a prefold is formed. This is obtained by the fact that the turning roller (31) has a double cone with the wide ends facing each other. The web is then guided past a first conveyor rail, which conveys a downward oriented longitudinal edge area (34) up into a position substantially parallel to an upward oriented longitudinal edge area (33) so that a U-shape is formed around a conic guiding member (35). In this manner it is possible to avoid the risk that the cold-sealing adhesive gets into contact with each other resulting in a risk that the machine may be stopped.

Description

A METHOD FOR USE IN PACKING ITEMS IN A NUMBER OF PACKING MA¬ TERIAL WEBS AND AN APPARATUS FOR USE IN THE METHOD

BACKGROUND OF THE INVENTION.

The present invention relates to a method for use in packing items and of a kind wherein a number of packing material webs are conveyed in a substantially vertical orientation of the web from a storage station where the web is stored in, preferably horizontally oriented, rolls to a forming station, where each web is given such an up¬ ward open cross sectional shape that they are able to receive the items to be packed, and through a filling station in which items are placed in the webs, a longitudinal sealing station where the longitudinal edges of each web are sealed to form packing tubes, a transverse sealing station where the packing tubes are sealed in the transverse direction of the webs, and a separation station for cutting the webs in the transverse seeding.

In the prior art methods of this kind a hot sealing adhesive is used for longitudinal sealing and transverse sealing of the packing around the items. Since adhesion or sealing will only occur in the adhesive after heating, it has been possible in the known methods to make a fold of the packing material web by means of traditional folding wheels and folding guides in immediate vicinity of the storage station. Therefore, the web has been conveyed to the forming station in a folded condition and has been easy to open for the formation of a cross sectional shape, preferably in the form of an up¬ ward open U-shaped cross section, before conveying the web into the forming station. This has taken place by means of side guides that open the folded web. An example of this method is known from Danish Patent No. 144,555.

According to this known method a number of rolls of web-shaped packing material are suspended in a storage station. From here each web is conveyed by means of ten¬ sion regulation rollers through a set of forming means for central folding of the web. The folded web is conveyed through several sets of guides and turning rollers around a last turning roller into the foming station. In the forming station the web is given its U-shaped cross section by means ofthe side guides. This method will not be applica¬ ble to webs that are supplied with a cold-sealing adhesive as the web would then be¬ come glued during its passage through guides and around turning rollers so that no opening can be effected in the forming station.

Today there is a general wish to use packing webs with cold-sealing adhesive. In such a web it is important that the web is held apart before the item is placed therein since any contact between parts of the web that have been supplied with the cold-sealing adhesive would cause a sealing ofthe web and consequently a machine stop.

Until now it has been normal in connection with packing material webs with cold- sealing adhesive that a supply roll is placed directly under or next to the packing ma¬ chine. By this arrangement the web is conveyed in a substantially horizontal orienta¬ tion toward the packing machine where a fold is made immediately prior to placing the item in the folded web. However, this is associated with severe disadvantages as the determining dimensioning of the packing machine, which may have up to 15-20 adjacent packing lines, has been the width of the web. This is disadvantagous, how¬ ever, since the width of the web is considerably wider than the width of the packed item. Consequently, there is a wish to reduce the width of the packing machine, espe- cially since it should often have a width corresponding to that of preceding equipment in the item production, e.g. ice lolly production machines, as well as a width corre¬ sponding to subsequent equipment, e.g. packing equipment.

Thus, there is a wish to use packing material webs that are provided with a cold- sealing adhesive and, also, there is a wish to reduce the width ofthe packing machines used.

It is the object of the present invention to offer a solution to this and to provide a method and an apparatus for use in the method, wherein it is possible to use packing material webs with a cold-sealing adhesive, and which has at the same time a packing machine width that is not determined by the width ofthe packing material webs used. This is obtained according to the present invention by a method ofthe type mentioned in the introduction being characterised in that the webs are provided with a cold- sealing adhesive for cold sealing both in the longitudinal direction and in the trans¬ verse direction of the web, that the web is conveyed from the storage station to the forming station in a non-folded state, that the folding is performed in the forming sta¬ tion by giving each web a central fold while the downward oriented longitudinal edge area of the web is brought up into a position substantially parallel to the upward ori¬ ented longitudinal edge area ofthe web to form a U-shaped cross section in which the items may be received. The web is preferably provided with a cold-sealing adhesive before being rolled up. Thus, the rolls stored in the storage station will contain a web that is provided with an adhesive.

As the material web is conveyed from the storage station in a substantially horizontal orientation and in a non-folded condition, it is possible to use a separate storage sta- tion and a web conveyance substantially corresponding to the one described in Danish

Patent No. 144,555.

As the application of a central fold and the upward conveyance of the downward ori¬ ented longitudinal edge are ofthe web take place in the forming station, there will be no risk of sealing the material web when it is conveyed to the forming station. Fur¬ thermore, simultaneous formation of a central fold and upward conveyance of the downward oriented longitudinal edge area ofthe material web may take place within a width that is smaller than the width of a single packing line since the maximum ex¬ tension in the transverse direction will occur when the web has been folded up com- pletely for formation of the U-shaped cross section, which is obtained immediately before the filling station.

According to a preferred embodiment the method is characterised in that each web is folded around a double conic turning roller, which preforms a central fold in the longi- tudinal direction of the web and which co-operates with a first web conveyor, which conveys the downward oriented longitudinal edge area upward, and that the U-shaped cross section is formed around a second web conveyor. The double conic turning roller will preferably be constructed in such a manner the wide ends ofthe cones face each other. The web is led around such a rotating turning roller with the side provided with adhesive facing the turning roller. Alternatively, it will also be possible to use double conic turning rollers in which the small ends ofthe cones face each other. In this case it is preferred for the side ofthe web provided with adhesive to turn away from the turning roller.

It is an important feature that the material is given a prefold. Such a prefold may also be accomplished by using fixed guides in stead of a turning roller. It is important that an mdication of the location of the fold on the web is ensured, irrespective whether this takes place at the intersection ofthe two cones or by use of a fixed guide.

When the U-shaped cross section has been formed, the items are placed in the web immediately afterwards. This minimises the risk that the parallel sides ofthe web get into contact with each other in an unintended manner before they are conveyed through the sealing members.

The sealing members and the cutting members function by simply performing a squeezing of the material web. This may be accomplished by using pressure rollers, jaws or other squeezing members.

When using a cold sealing there will be no risk of an unintended heating, which might be damaging to the items to be packed, e.g. ice lollies. The method will preferably be used in connection with step-by-step conveyance ofthe webs, but may also be used in continuous conveyance of the webs. For an illustration of a method of step-by-step conveyance reference is made to the description of Danish Patent No. 144,555. Thus, the method according to the present invention may be seen as a further development or modification ofthe method described therein with the object of using packing material webs with a cold-sealing adhesive.

The invention further relates to an apparatus for use in the method having a storage station where a number of packing material webs provided with a cold-sealing adhe- sive are stored wound up in, preferably horizontally oriented, rolls, a forming station with members for giving each web such a cross sectional shape that it is able to re¬ ceive items to be packed, a filling station with members for placing the items in the webs, a longitudinal sealing station with members for sealing the longitudinal edge areas ofthe webs for the formation of packing tubes, a transverse sealing station with members for forming a sealing in the fransverse direction of the webs, a separation station with members for cutting the webs in the fransverse sealing, and guiding mem¬ bers for holding the webs in a substantially vertical orientation during conveyance to the forming station. According to the invention said apparatus is characterised in that the members for longitudinal and transverse sealing are squeezing members for squeezing the lateral edge areas of the webs together to form packing tubes and squeezing members for squeezing the packing tubes together in fransverse direction of the longitudinal direction ofthe webs between items positioned therein, that the guid¬ ing members are designed to direct the webs in a non-folded condition from the stor- age station to the forming station, which is located immediately before the filling sta¬ tion and which comprises a turning roller arranged as a folding roller forming a longi¬ tudinal central prefold in the web, and a first guiding member conveying the down¬ ward oriented longitudinal edge area of the web upward into a position substantially parallel to the upward oriented longitudinal edge area ofthe web to form the U-shaped cross section in which the items may be received.

Such an apparatus is advantageous because it will be possible in a simple manner to modify a packing apparatus of the type described in Danish Patent No. 144,555 such that packing material webs with a cold-sealing adhesive may be used in the apparatus while at the same time the existing width of the packing machine is maintained and while the original storage station is obtained.

It should be noted that it is preferred to store supply rolls of the web in a horizontal position for considerations of an easy and adequate exchange of rolls in the storage station. However, it is also possible to use a storage station with rolls positioned ro¬ tatably around vertical axes. DESCRIPTION OF THE DRAWING.

The invention will now be explained with reference to the accompanying drawing, wherein:

Fig. 1 shows a packing apparatus according to the invention with several packing lines, seen from above; Fig. 2 shows a view according to the arrow II in Fig. 1 ;

Fig. 3 shows a schematic view to illustrate a single packing material web being passed through the apparatus by exercising the method according to the inven¬ tion; Fig. 4 shows a cross section through the turning roller used in the apparatus according to the invention; Figs. 5 and 6 show a view seen from the side, respectively from above, of a first and a second guiding member used in the apparatus according to the invention; and

Fig. 7 shows a view corresponding to Fig. 3.

The packing apparatus shown in Fig. 1 comprises two storage stations 1 and 2, each of which is provided with a number of rolls 3 of packing material, e.g. paper, which has been supplied with a cold-sealing adhesive.

The packing apparatus is designated by 4 and, as appears particularly from Fig. 2, consists of a rack 5 supplied with a gallows 6, which carries downward projecting fingers 7, the number of which corresponds to the number of webs and which are ar- ranged on a line in fransverse direction of the machine direction. Positioned prior to the fingers is a forming station 8, which gives the webs a U-shaped cross section as they pass through the forming station 8. Between the forming station 8 and the fingers 7 the apparatus is provided with a filling station for putting the items into the U- shaped webs. The items are arranged on a line in transverse direction of the machine direction by means ofthe fingers. 7. The rack 5 is provided with longitudinal sealing members 9 by means of which the longitudinal edge area of each web is sealed. The longitudinal sealing members 9 consist of squeezing rollers which squeeze the webs together to form packing tubes. Arranged after the longitudinal sealing members 9 are folding members 10 which lay down the formed sealing extending in the longitudinal direction.

The apparatus further comprises a fransverse sealing station with squeezing members 11-14 for the formation of fransverse sealings. Thus, a first fransverse upper bar 11 and a first fransverse lower bar 12 as well as a second fransverse upper bar 13 and a second fransverse lower bar 14 have been formed. The upper and lower bars are able to co-operate in pairs to squeeze packing tubes between items positioned inside them. Thus, the upper bars 11 and 13 are interconnected by means of arms 15, and the lower bars 12 and 14 are interconnected by means of arms 16. The second upper bar 13 and the second lower bar 14 are connected with an engagement and disengagement mechanism 17 by means of which the two upper bars 11, 13 can be moved upward while the two lower bars 12, 14 can be moved downward simultaneously. The dis- tance between the two sets of bars corresponds to the length of packings to be pro¬ duced. The transverse sealing station formed by these members may be moved back and forth in the machine direction with a stroke corresponding to the length of the packings to be produced. After the fransverse sealing station follows a confrol panel 20 and after that a separation station 21 as well as a roller conveyor 22 for separated packings.

The packing apparatus shown in Figs. 1 and 2 functions in the following manner.

Before starting, the webs 23 are introduced between a number of guides 24 (for the sake of simplicity only two sets of guides 24 are shown). Then the webs are intro¬ duced through the forming station 8. A detailed explanation of the forming station 8 will be given below with reference to Fig. 3. Each web is then introduced under its respective finger 7 through the longitudinal sealing station 9, through the seam layer members 10 and between the disengaged upper and lower bars 11, 13 and 12, 14, re- spectively. Then the web is taken to the separation station 21 and out through its cut¬ ting members. It will be understood now that by giving the engagement and disen¬ gagement mechanism 17 a stroke forward and backward and by closing the first upper and lower bars 11, 12 before starting a forward stroke and opening said upper and lower bars 11, 12 at the end of the stroke, the web 23 will be conveyed stepwise through the apparatus, and items laid down in front of the fingers 7 and arranged on a line by means of these will be wrapped in packings, which are separated from the webs by means ofthe separation station 21. It will be seen now that the second set of upper and lower bars 12, 14 may be left out since just one co-operating upper and lower bar 11, 12 will be sufficient to perform the stepwise conveyance ofthe webs 23.

Fig. 3 is a schematic view to illustrate the passage of a web 23 through a single pack- ing line in a packing apparatus according to the invention. The apparatus will, of course, have several packing lines as explained in connection with Figs. 1 and 2. For the sake of simplicity, however, only one line is shown.

The web 23 is conveyed between guides 24 in the direction of the arrows 25. 26 des- ignates a roll of web-shaped packing material suspended in a storage station. The web is led around a stretching roller 27. In the storage station the web 23 will have a sub¬ stantially horizontal orientation as the roll 26 rotates around a horizontal axle 28. The web is led around a set of guides 29 consisting of two rollers between which the web 23 passes. Then the web 23 is led through one or more straightening guides 30 consist- ing of rollers having a gradually increasing angular position until the web 23 is ori¬ ented in vertical direction when passing through a first vertical guide 24. The first set of vertical guides 24, which is shown in Fig. 3, will be placed in immediate vicinity of a storage station 1, 2. The web 23 may be supported by a number of corresponding vertically oriented guides 24 depending on the distance from a storage station 1, 2 to the forming station 8. Typically, there will be a number of three to seven sets of verti¬ cal guides 24.

The web 23 is then conveyed into the forming station 8, where it is first led around a double conic turning roller 31 , which has the cones arranged with the wide ends facing each other. The forming station further comprises a first guiding member in the form of a smooth rail 32 co-operating with the side of the web that turns away from the turning roller 31. The rail 32 is arranged with a gradually rising course from a position substantially at the point where the cones of the folding roller coincide to a position substantially at the upper side ofthe upward oriented longitudinal edge area 33 ofthe web 23. As the web is conveyed along the first guiding member 32, the downward oriented longitudinal edge area 34 ofthe web will be conveyed upward around a sec- ond guiding member 35 into a position substantially parallel to the upward oriented longitudinal edge area 33 of the web. In this manner a U-shaped channel is formed, which is led into an additional guide 36 comprising tracks to receive the two longitu¬ dinal edge areas 33, 34 ofthe web 23. An additional guiding member 35 is provided in the form of a cone-shaped guide having its pointed end turned in the direction of movement 25 ofthe web.

An item in the form of an ice lolly 37 is laid into the U-shaped channel by means of laying members 38. The item is positioned as explained with reference to Figs. 1 and 2. Fig. 3 shows a guide 39 provided with two tracks to hold the two longitudinal edge areas 33, 34 ofthe packing web apart immediately before they are introduced into the longitudinal sealing station 9.

It will be seen that when passing around the turning roller 31 , which functions as a folding roller, the web 23 will be given a central prefold. Then the smooth rail 32 will cause a double folding ofthe web 23 in the first course from the turning roller 31 and past the second guiding member 35 until the web 23 has assumed its U-shaped cross section immediately before it is introduced into the guide 38.

It should be noted that the turning roller 31 will have a spatial orientation which is adjusted once and for all in a packing machine. This is accomplished by mounting the turning roller 31 in the rack 5 by means of a swivel joint. This spatial position will depend on the distance from the turning roller to a vertical plan situated between the number of guides 24 between which the web 23 passes. The distance from the last vertical guide 24 to the turning roller 31 , as measured in the longitudinal direction of the web, will also be significant to the spatial angle. The spatial angle will be between 0° and 30° relative to a vertical axis of intersection between the mentioned vertical plan passing between the vertical guides 24 and a horizontal plan through the U- shaped web. The turning roller 31 will have a cone angle that is between 5° and 15°, preferably between 10° and 12°.

The taming roller 31, the guides used and the second guiding member 35 will be pro- duced from a friction inhibiting material, preferably delrin. Altematively, teflon may be used for the second guiding member 35 and the guides. This will reduce the friction between guides/rollers and the side ofthe web 23 supplied with adhesive.

Even though Fig. 3 shows a double cone with the wide ends facing each other, it will be possible altematively to use a double cone-shaped turning roller in which the wide ends turn away from each other. This is shown in Fig. 7. In this case the web will ex¬ tend with its side provided with adhesive turning away from the roller. Altematively, it will also be possible to use other members, e.g. filamentous guides, as long as it is ensured that a prefold is formed immediately before the introduction of the web 23 into the space between the first and second guiding members 32, 35.

It should further be noted that altematively the smooth rail 32 may be replaced by a number of point-by-point supports the surfaces of which contacting the web 23 have a gradually increasing course corresponding to the course ofthe upper side 41 ofthe rail 32, which is in contact with the paper web.

Fig. 4 shows a cross section through the turning roller 31, which is formed by two cones 42 placed with their wide ends 43 facing each other so that an edge 44 results. The edge 44 will indicate the prefold of the web 23 as it passes around the roller 31. The roller is rotatably suspended around an axle (not shown), which passes through a central bore 45. The axle is fastened to the rack 5 of the apparatus by means of a swivel joint.

The mutual positions of the first and second guiding members in the form of the smooth rail 32 and the cone-shaped guide 35 are seen Figs. 5 and 6. For the sake of simplicity the paper web 23 has not been included in these figures. The guide 35 may altematively be designed as a number of punctiform supports having the same course as the cone shown. This will reduce friction.

When using the apparatus according to the invention it will be possible for the web 23 to be conveyed in a vertical orientation between the vertical guides. Due to this the individual packing lines in the packing apparatus may be position as close as the width of the packed items permits. The paper web is prefolded from its vertical orientation around the turning roller 31 as the sharp edge 44 between the wide ends 43 ofthe two cones will make an indication of the prefold. The folding is continued by the folding ofthe web over the smooth rail 32 where the web 23 is folded into its U-shape around the cone-shaped second guiding member 35.

By vertical conveyance of the web 23 in a non-folded condition the risk is avoided that parts of the web provided with adhesive might get into contact with each other and consequently jeopardise the functioning of the apparatus. At the same time it is possible to obtain a narrow packing apparatus and an adequate position of the supply rolls 26 arranged with a horizontal orientation in the storage station 1, 2.

Claims

1. A method for use in packing items (37) and of a kind wherein a number of packing material webs (23) are conveyed in a substantially vertical orientation ofthe web from a storage station (1, 2) where the web is stored in, preferably horizontally oriented, rolls (3) to a forming station (8), where each web (23) is given such an upward open cross sectional shape that they are able to receive the items (37) to be packed, and through a filling station (38, 39) in which items are placed in the webs, a longitudinal sealing station (9) where the longitudinal edges (33, 34) of each web (23) are sealed to form packing tubes, a fransverse sealing station (11-14) where the packing tubes are sealed in the fransverse direction of the webs, and a separation station for cutting the webs (23) in the fransverse sealing, c h a r a c t e r i s e d in that the webs (23) are provided with a cold-sealing adhesive for cold sealing both in the longitadinal direc¬ tion and in the fransverse direction ofthe web (23), that the web is conveyed from the storage station (1, 2) to the forming station (8) in a non-folded state, that the folding is performed in the forming station (8) by giving each web a central fold while the downward oriented longitudinal edge area (34) ofthe web is brought up into a position substantially parallel to the upward oriented longitudinal edge area (33) of the web to form a U-shaped cross section in which the items (37) may be received.

2. A method according to claim 1, c h a r a c t e r i s e d in that the webs (23) are folded around a double conic turning roller (31), which preforms a central fold in the longitadinal direction of the web and which co-operates with a first web conveyor (32), which conveys the downward oriented longitadinal edge area (34) upward, and that the U-shaped cross section is formed around a second web conveyor (35).

3. A method according to claim 1 or 2, c h a r a c t e r i s e d in that the items (37) are placed in the U-shaped cross section immediately after it has been formed.

4. An apparatus for use in the method according to claim 1 having a storage station (1 ,

2) where a number of packing material webs (23) provided with a cold-sealing adhe- sive are stored wound up in, preferably horizontally oriented, rolls (3), a forming sta¬ tion (8) with members (31, 32, 35) for giving each web (23) such a cross sectional shape that it is able to receive items (37) to be packed, a filling station with members (38, 39) for placing the items in the webs, a longitadinal sealing station (9) with mem- bers for sealing the longitadinal edge areas (33, 34) of the webs for the formation of packing tabes, a fransverse sealing station with members (11-14) for forming a sealing in the fransverse direction ofthe webs (23), a separation station (21) with members for cutting the webs in the fransverse sealing, and guiding members (24) for holding the webs (23) in a substantially vertical orientation during conveyance to the forming sta- tion (8), c h a r a c t e r i s e d in that the members for longitudinal and fransverse sealing are squeezing members (11-14) for squeezing the lateral edge areas (33, 34) of the webs together to form packing tabes and squeezing members (11-14) for squeez¬ ing the packing tabes together in fransverse direction of the longitadinal direction of the webs between items (37) positioned therein, that the guiding members (24) are designed to direct the webs (23) in a non-folded condition from the storage station (1,

2) to the forming station (8), which is located immediately before the filling station (38, 39) and which comprises a tuming roller arranged as a folding roller (31) forming a longitudinal central prefold in the web, and a first guiding member (32) conveying the downward oriented longitadinal edge area (34) of the web upward into a position substantially parallel to the upward oriented longitadinal edge area (33) ofthe web to form the U-shaped cross section in which the items (37) may be received.

5. An apparatus according to claim 4, c h a r a c t e r i s e d in that the folding roller (31) is a double conic roller and that the first guiding member is a smooth rail (32) co- operating with the side of the web turning away from the U-shaped cross section and having a gradually rising course (41) from a position substantially at the point where the cones (42) ofthe folding roller coincide to a position substantially at the upper side ofthe upward oriented longitadinal edge area (33) ofthe web.

6. An apparatus according to claim 5, c h a r a c t e r i s e d in that adjacent to the guiding rail (32) a second guiding member is positioned in the form of a substantially cone-shaped guide (35) around which the web (23) is folded into its U-shape.

7. An apparatus according to claim 5 or 6, characterised in that the cone angle ofthe folding roller (31) is between 5° and 15°, preferably between 10° and 12°, and that the folding roller is positioned at an spatial angle of between 0° and 30° relative to an axis of intersection between a vertical plan of the web conveyance and the U- shaped web.

8. An apparatus according to any one of claims 5-7, characterised in that the double conic folding roller (31) has the wide ends ofthe cones (42) directed toward each other, and that the side ofthe web (23) provided with adhesive faces the folding roller.

9. An apparatus according to any one of claims 4-8, characterised in that the folding roller (31) and the guiding members (24) that are in contact with the side of the web provided with adhesive are produced from a material inhibiting friction, pref- erably delrin.

10. An apparatus according to claim 4, characterised in that the first guiding member (32) is a row of point-by-point supports having a gradually rising course from a position substantially at the point where the cones (42) coincide to a position sub- stantially at the upper side of the upward oriented longitadinal edge area (33) of the web.