AU1545002A - Device for packaging machine - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: PPI AUSTRALASIA PTY LTD Invention Title: DEVICE FOR PACKAGING MACHINE 0 .0 0* 0 0 The following statement is a full description of this invention, including the best method of performing it known to me/us: [ements received on: B FEB 22 r:v 2 DEVICE FOR PACKAGING MACHINE Field of the Invention The present invention relates to an auxiliary device for packaging machinery intended to pack products inbags made of sheet material having self-adhesive labels affixed thereon.

Background to the Invention In the packaging industry it is known to use a preforming device (sometimes referred to as a "neck" or "forming shoulder") to guide a sheet material around a product feed tube and into an orientation where the sheet material can be formed into a bag. To simplify the following description, this pre-forming device will also be referred to as "pre-forming neck" or simply a "neck".

15 Horizontally and/or vertically fed packaging machines are known in the art, in which the bag sheet .material is provided in a roll as eg. flat sheet or roll 0-60 film, as monomaterial rolls, or a roll of multimaterial compound formed by lamination and/or coating. These 20 machines include a feed tube for the product to be packaged or bagged, and this tube, along with other associated components, assists with the forming, feeding, sealing and cutting of successive bags in a continuous production.

The roll of sheet material is unwound at a constant stress, and is fed into the pre-forming neck which causes the path of the sheet to move into proximity with the feed tube, so that it is then longitudinally wrapped along the feed tube. The pre-forming neck has a front sheet material feed-in sector, arranged substantially transverse to the feed tube, and a rear sector from which the sheet material exits, the rear sector being parallel to and slightly separated from the feed tube. After the sheet material has been directed around the feed tube a longitudinal seal is formed to join adjacent sheet edges. Thereafter, a first transverse seal extending across the resultant laminar sheet material tube is formed, and the product to be 10 packaged is then loaded into this laminar tube, falling against the transverse seal. A second transverse seal, at oooo a predetermined distance above or from the first seal, is formed, and the resultant product-containing bags are then cut in series to separate them from the remainder of the laminar tube.

The packaging machinery thus further includes a drawing means that acts on the laminar sheet material tube to cause it to progress, a longitudinal sealing means to seal adjacent edges of the sheet material to define the 20 laminar tube, and cross sealing-cutting means that facilitates the final stage of the production of single bags, after the corresponding product is enclosed therein, the sealing-cutting means performing the successive steps of sealing and then cutting.

Attempts have been made to use this packaging machinery to produce a bag in which at least one of its inner faces has a self-adhesive label affixed thereon. In use of this known machinery a problem of label detachment occurs during the passage of the sheet material through the pre-forming neck. The present inventors have noted that this problem is exacerbated when the sheet material moves forward onto the pre-forming neck and passes over a ridge defining a transition region, where the sheet material converts from a substantially flat form into a tubular form. The inventors have noticed that as each label passes over this ridge, any abrupt shift in the direction of the sheet material causes at least a partial 10 detachment of the label, and this often results in a :I complete detachment of the label. Thereafter the label may adhere to the external face of the feed tube or even block or foul some elements of the machinery, causing failures and downtime in the functioning thereof. There e e 15 is also a risk that a label can become mixed up with the product packaged in the bags (eg. with attendant health .i risks) Summary of the Invention The present invention therefore provides an 00.. 20 auxiliary device for a packaging machine that packs products in bags made of sheet material having labels affixed thereon, the machine including a pre-forming neck arranged substantially transversely to a bag-forming tube intended to fill the bags with product to be packed, the pre-forming neck having a front sector for receiving the sheet material with labels affixed thereon, a rear sector that is typically parallel to a surface of the bag-forming tube surface, the rear sector directing the sheet material to form a sheath around the bag-forming tube, and a ridge between the front and rear sectors, the ridge defining a transition zone for the sheet material as it moves from its initial flat form into a tubular (and sheathing) form on the bag-forming tube; the device including at least one guide member for the sheet material having a front portion and a rear portion that are respectively complementary (typically parallel) to the front and rear sectors of the pre-forming neck, with a guide space for the sheet 10 material and affixed labels being defined between the :i front and rear portions of the guide member and the respective front and rear sectors of the pre-forming neck.

ooo o The present invention therefore provides a device that may be connected to a pre-forming neck which, along 15 with the bag-forming tube in that machine which also serves as a feeding tube, and receives and carries the sheet material with labels, to provide bags filled with the products intended to be packed.

Bags manufactured by means of the use of the packaging machine include, for example, "pillow" or "three-seam pillow" packages, three-seam bags with a flat top or a flat bottom, and envelopes with three or four seams.

Preferably the guide space is defined sufficiently narrowly to allow the sheet material and labels to pass therethrough unhinderedly but so as to prevent label removal.

Preferably the packaging machine includes sealing and cutting means in association with the bag-forming tube to seal and cut a joining strip between bags successively obtained from, for example, a roll of such sheet material, Brief Description of the Drawings Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in 10 which: Fig. 1 is a perspective view of a packaging machine incorporating a device in accordance with the present invention; Fig. 2 is a partial side cross-sectional view showing an outline of a prior art bag-forming tube and pre-forming neck through which a sheet material with selfadhering labels affixed thereon is passing, the detachment of one of the labels being shown; Fig. 3 is a view similar to that shown in Fig. 2, but wherein a device according to the present invention is fitted, the Figure showing the way in which the device acts on a self-adhering label affixed on the sheet material; Fig. 4 is a perspective view showing part of the assembly of Figure 1 including the forming tube and the pre-forming neck and including a device according to the present invention, with the sheet material fed to form the bags also being depicted; Fig. 5 is a cross-sectional plan view of the assembly of Figure 4 showing the forming tube and the preforming neck including the device of the present invention, the sheet material also being illustrated; Fig. 6 is a cross-sectional plan view, similar to that shown in Fig. 5, showing an alternative assembly layout, wherein the forming tube and the pre-forming neck include a pair of devices according to the present invention; and 10 Fig. 7 is a partial perspective view similar to Figure 4 but showing the incorporation of a complementing member in the pre-forming neck.

ooI Modes for Carrying out the Invention The present invention was developed to either be 15 retro-fitted to existing machines or to be incorporated into newly manufactured pre-forming necks. The preferred devices of the invention were developed to be easily constructed and assembled, and to be implemented easily.

The preferred devices were developed to ensure that the labels were kept affixed on the sheet material during any (particularly abrupt) change in its motion through the pre-forming neck.

Referring now to Fig. 1, a packaging machine with a roll of sheet material 1 from which bags to pack the corresponding products are formed is schematically depicted. This machine has a compensating train 2, including a group of rolls 3 to achieve a constant stress in the sheet material 4 unwinding from roll 1.

8 In order to form the bags and pack the products therein, the sheet material 4, with labels already affixed thereon or applied during the unwinding process, and referred to as 15, is fed into a pre-forming neck 5. The neck is attached to a forming tube 6, adjacent to which drawing means 7 are disposed to advance forward the sheet material 4. The neck 5 has a front sector 8, where the sheet material 4 is fed into, and a rear sector 9, surrounding tube 6, where the sheet material 4 is disposed in a tubular or sheathing manner and moves stepwise along -"the same.

In order to seal the sheet material 4 in a tubular manner and thereby obtain bags, longitudinal sealing means and transversal sealing means 11 are provided. Upon sealing closed a strip 12 of the bags, corresponding to successive bags 13, a predetermined amount of the product SS.. to be packed is filled therein from the inside of the tube 6. Upon completion of the filling step and sealing of each bag, the respective strip 12 is cut with cutting means provided in the sealing means 11, as is known in the art.

A reading device (not shown) controls the extent to which the sheet material 4 progresses for each packaging step, the reading device sensing the presence of marks defined on the sheet material 4, such as those indicated at 14.

Fig. 2 clearly depicts the problem arising from the use of prior art machinery concerning the detachment of labels 15, as explained above. As seen in Fig. 2, the machinery of the prior art has in the forming neck between front 8 and back 9 sectors, a ridge 16 defining a transition area of the sheet material 4 where it changes from its initial flat form into a tubular and sheathing form around the forming tube 6. The ridge 16 causes an abrupt change in the forward direction of the sheet material 4 and, consequently, in the labels 15. This is why the front edge 15' of the labels often detaches.

In accordance with the present invention and as illustrated in Figs. 3 and 4, the auxiliary device of the 10 present invention comprises a guide member 17, having a side flap 18 for securement on the pre-forming neck 5, on which it is mounted, for instance, by means of supports 19. The guide member 17, which is typically made from flexible and non-sticking sheet material (eg. from 15 "teflon" or from a rigid sheet material), has a front

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portion 20 and a rear portion 21. These portions respectively complement front 8 and rear 9 sectors of the pre-forming neck 5, to define a guide space 22 through which the sheet material 4 with the labels 15 affixed thereon moves forward. The guide space 22 defines typically a narrow gap between the pre-forming neck 5 and the guide member 17 that is at least equal to or slightly larger than the maximum overall thickness defined by the sheet material 4 and one label 15, at least in the transition zone defined adjacent to the ridge 16. In turn, the transition between the front 20 and rear 21 portions of the guide member 17 defines a ridge 23, the transversal radius of curvature of which is preferably equal to the radius of curvature of the ridge 16 of the pre-forming neck 5. Thus, the guide member 17 establishes a limit for the labels 15, such that even when the transition of the forward motion of the sheet material 4 is very abrupt when passing through the ridge 16 of the pre-forming neck the labels are kept in place on the sheet material 4, with no chance of label detachment. Consequently, the bag producing process and the bagging of products can continue to be carried out efficiently, thus overcoming the problems associated with the detachment of labels In a similar but alternative way to the embodiment illustrated in Fig. 4 and Fig. 5, it can be seen that the guide member 17 comprises a member partially extending cross-wise of the pre-forming neck 5, as shown in Fig. 6.

15 Whenever it is deemed convenient, two and typically a pair of symmetrical guide members 17 can be mounted on the preforming neck 5, each of them partially covering the width of the pre-forming neck Fig. 7 depicts an alternative embodiment to Figures 5 and 6. In this embodiment a complementing member in the form of supplementary member 24 can be arranged transversely to the ridge 16 of the pre-forming neck The supplementary member 24 defines a transition zone, the radius of curvature of which is larger than ridge 16, in order to make the sheet material and label transition even less abrupt, and thus, less aggressive during the passage of the labels It is worth mentioning that the device of the present invention may be partially or completely removed to enable threading of the sheet material 4. The device is typically also flexible enough to absorb over-thickness of the sheet material 4, such as with joints, wrinkles, etc.

Whilst the invention has been described with reference to a number of preferred embodiments, it will be appreciated that the invention can be embodied in many 10 other forms.

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Claims (10)

1. 2. A device according to claim 1, wherein the front and rear portions of the guide member are separated from the corresponding front and rear sectors of the pre- forming neck, at least in the transition zone, by a gap which is at least equal to the maximum overall thickness defined by the sheet material and one of the labels affixed thereon.
2. 3. A device according to claims 1 or 2, wherein an opposing ridge, the transversal radius of curvature of which is substantially equal to the radius of curvature of the ridge of the pre-forming neck, is defined between the front and rear portions of the guide member.
3. 4. A device according to any claim 1 to 3, wherein the front and rear portions of the guide member extend transversely with respect to the pre-forming neck.
4. 5. A device according to any claim 1 to 3, including a pair of symmetrically arranged guide members in the pre- forming neck, each extending at least partially for the o.oo. width of the pre-forming neck.
5. 6. A device according to any one of the preceding S" 15 claims, wherein the guide member includes a securing side flap.
6. 7. A device according to any one of claims 1 to
7. 9.o9 wherein the guide member includes a side flap that is secured to the pre-forming neck. 8. A device according to any one of the preceding claims, wherein the guide member is made of flexible sheet material. 9. A device according to any one of claims 1 to 7, wherein the guide member is made of rigid sheet material.
8. 10. A device according to any one of the preceding claims, wherein the guide member is arranged to extend over the pre-forming neck. 14
9. 11. A device according to any one of the preceding claims wherein the machine further includes means to seal and cut joining strips between successively obtained bags from the sheet material.
10. 12. An auxiliary device for a packaging machine substantially as herein described with reference to Figures 1 and 3 to 7 of the accompanying drawings. 10 Dated this 6th day of February 2002 PPI AUSTRALASIA PTY LTD By its Patent Attorneys GRIFFITH HACK De.