AU718525B2

AU718525B2 - Wrapping material

Info

Publication number: AU718525B2
Application number: AU25592/97A
Authority: AU
Inventors: Louis J Abrahams
Original assignee: AUSTRALIAN CHALLENGE OPERATION
Current assignee: Multiflex Packaging Pty Ltd
Priority date: 1996-06-18
Filing date: 1997-06-18
Publication date: 2000-04-13
Anticipated expiration: 2017-06-18
Also published as: AU2559297A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): AUSTRALIAN CHALLENGE (OPERATIONS) PTY LTD A.C.N. 006 407 567

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4* S Invention Title: WRAPPING MATERIAL S S

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The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 WRAPPING MATERIAL This invention relates to improved wrapping materials. In a preferred embodiment it relates to a film which adheres to itself, for example a stretch cling polyethylene, and provides an area of reduced cling which facilitates removal of the film from the wrapped object. The film of the invention is particularly useful for wrapping rolled newspapers.

BACKGROUND OF THE INVENTION 0 Home delivery of unprotected newspapers, although still widely practised, is unsatisfactory, particularly in wet and/or windy weather, and is subject to widespread customer complaints. In response to these complaints many newsagents supply newspapers which have been machine rolled into a tubular shape while at the same time rolling around a thin cling stretch plastic. The film protects the paper from moisture and contamination while holding the newspaper in a rolled form. This also has the advantage that the o:o• wrapped newspaper may be conveniently delivered without damage by throwing it from a moving vehicle.

The wrapping material is plastic film of the kind which oooo• adheres to itself, the overlapping areas of the film having considerable shear strength which prevents the newspaper from unrolling until the wrapping is removed.

In order to remove the wrapping without tearing or cutting the film, which is difficult to accomplish manually due to the tensile strength and extensible properties of the film, especially where it is adhered to the contiguous layer, it is necessary to locate the cut edge of the film and peel it back on itself, thereby separating the adhered layers and releasing the contents. However, the cut edge is staff/ieonalkeep/speci/prov.aus.challenge 17.8 3 practically invisible and therefore difficult to locate, and when located is difficult to separate from the contiguous layer to which it is adhered in order to start the peeling process, thus causing considerable annoyance and frustration to the consumer.

THE PRESENT INVENTION The present invention provides a new facility for easy removal of cling wrap from an object such as a rolled newspaper.

1 In a principal aspect the invention provides a cling wrap film having a continuous or discontinuous coating applied thereto in the form of a longitudinal strip or band, the coating having the effect of reducing the tack or cling of the film in the area which is coated. The coating is preferably printed on the film in the form of a longtitudinal band or strip which provides, in use, a visible indication of the direction in which separation of the outermost layer of the wrap from a contiguous inner layer may conveniently be commenced, thereby facilitating location of the cut edge of the wrap and removal of the wrap from the wrapped object.

PRIOR ART Australian patent specification 566608 (31535/84) describes *oo an attachment to a newspaper rolling machine for applying a waterproof cling stretch plastic wrapping to a newspaper.

25 Recognising the abovementioned problem, the said specification 566608 provides in a preferred embodiment a facility for easy removal of the wrapping material. This facility provides a filament or strip which is fed in with the plastic film in such manner as to provide a tab which protrudes from the cut edge of the film and may be grasped stat /ioolnkek/spci/prov.aus.ialleng. 17., 4 by the person unwrapping the newspaper in order to commence the peeling-back process.

Australian specification AU-B-27364/92 (648442) discloses apparatus for, and a method of wrapping a newspaper in a web of stretch-wrap material which includes a web of dissimilar material which does not cling to the first material and thereby facilitates the unwrapping process.

Australian specification AU-B-31535/84 (566608) discloses an attachment for a newspaper rolling machine for applying 10 a waterproof covering, preferably cling-type film, around the rolled newspaper.

Australian specifications 4913/54 (212005) and 13107/66 relate to machines for rolling and wrapping newspapers in a paper wrapper which is gummed into place.

15 The prior art neither discloses nor remotely suggests the provision of printed indicia on the wrapping material as provided by the present invention. It will be appreciated that the present invention requires no modification of the .wrapping machine nor any special skill on the part of the operator, as the roll of film of the invention is simply loaded into the wrapping machine in place of the conventional film and therefore provides a solution to the problem of unwrapping cling-film wrapped newspapers which is both convenient and cost-effective.

DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, cling wrap is provided with at least one longitudinal strip or band bearing a continuous or discontinuous coating, the coating having the effect of reducing the tack or cling of the film staff/ieona/keep/speci/prov.aus.challenge 17.6 5 in the area which it covers. The band may be linear or non-linear, and may for example be serpentine, serrated or crenellated. A non-linear band will almost always be out of register with the band on the contiguous layer at the cut edge, thereby making the location of the cut edge even more conspicuous. In practice we have found that a linear band is also frequently out of register as illustrated in the accompanying drawings, which in addition to the indicia further assists in the location of the cut edge for ease of commencement of the unwrapping process. Preferably the coating is visible so that the location thereof is immediately apparent. The coating provides a location .i where the cling of the outer layer is reduced, particularly S- at the cut edge where peeling of the film to remove it may 15 be initiated. The coating preferably is applied in a manner which indicates the direction in which peeling is to be effected. In this embodiment the cut edge is conveniently located by rubbing a finger or thumb around a ooaa the strip in the indicated direction. The cut edge, which 20 has less adherence to the contiguous layer in the coated area, tends to lift when this is done and is thereby easily located to commence the peeling process.

The stretch film is preferably stretch cling polyethylene, produced by the blown or cast process, which is adherent predominantly on one side. Although two sided cling film may be used, this may cause a problem where a number of wrapped objects are stored or carried in close proximity to each other as they may stick together.

The width of the band or bands may for example be between 15 to 40 mm and may be solid or patterned. The release coating is preferably applied to the plastic film, which has been produced by blowing or casting, during the manufacturing process. The film may be coated or printed either in-line or off-line.

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DRAWINGS

In the accompanying drawings: Figure 1 illustrates a preferred embodiment of the invention in which the continuous film 1 has been printed with a release agent in the form of arrows 2 bordered by parallel lines 3 along a longitudinal band 3.

It will be appreciated that the film retains its cling in the unprinted areas. Other patterns of printing or even a solid band of release agent may be used.

10 Figure 2 illustrates a newspaper rolled in the film showing the band 4 (the exact location of the band is not important).

Figure 3 is an enlarged view of the central S* section of the wrapped newspaper of Figure 2, showing how 15 imperfect registration of the print on the outermost layer with the print on the contiguous layer 6 may give a further, visible indication of the location of the cut edge 7, where the print on the outermost layer is displaced compared with the print on the contiguous layer. The arrows also function to indicate the direction in which peeling of the outermost layer should be commenced.

Figure 4 illustrates the central section of Figure 3 showing the cut edge which has been lifted at 8 in the direction of the arrow, thereby commencing separation of the outermost layer from the contigous layer.

It will be appreciated that although the location of the cut edge is shown by a line in the drawings for purposes of illustration, in actual use the cut edge will be practically invisible.

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EXAMPLE

A preferred embodiment of the invention is described in the following example.

Example Details of the extrusion process are known to persons skilled in the art. We prefer to use a three-layer coextruded film produced on a blown film extrusion line using linear low density resins. A PIB (polyisobutylene) oil is added to the resin as it is fed into the extruder to create 10 the cling effect on the film. The polyethylene tube produced is flattened to produce a layflat tube and a corona discharge treatment is applied to the film in the area where the print/release coating is to be applied, to enhance adhesion of the coating.

S 15 The layflat tube passes through two printing stations on a flexographic printing press where each outside surface of the layflat tube is printed with one or more bands of print/release in the chosen pattern. The print/release is transferred to the film using photopolymer printing plates which are located on the printing cylinders to reproduce the print in the desired locations on the finished rolls.

The ink used is water based and is dried as the web is passed through the drying sections of the printing press where hot air is blown on the printed film. Water based inks are preferred due to their safety and favourable environmental factors; no solvents are required.

Our preferred pattern as illustrated in the accompanying drawings is a longtitudinal strip of repeated arrows bordered by two pairs of parallel lines, which we have found to be very effective for the purpose of the staff/ieona/keep/speci/prov.aus.challenge 17.6 8 invention, but the actual nature of the pattern is not critical provided it assists in locating the cut edge to facilitate commencement of the unwrapping process.

Additional material such as advertising material may be included in the pattern. The strip may for example be about 40 mm wide and extend substantially the entire length of the film.

After printing the layflat tube is split, for example by trimming 50 mm off each side, to form two sheets which are rolled separately, and each of these sheets may be split further. A film about 500 mm wide is suitable for wrapping newspapers, and the printing is arranged so that each 500 mm roll bears a longtitudinal printed strip located approximately at the centre of the web as illustrated in 15 Fig. 1. However, the actual location of the strip is not S important, and it may be positioned off-centre.

"It will be clearly understood that the invention in its general aspects is not limited to the specific details referred to hereinabove.

This application is associated with provisional application PO 0486, and the entire disclosure in the specification of the said provisional application is by this cross-reference incorporated into the present specification.

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Claims

1. A cling wrap film having a continuous or discontinuous coating applied thereto in the form of a longitudinal strip or band, the coating having the effect of reducing the tack or cling of the film in the area which is coated.

2. A cling wrap film according to claim 1 wherein the coating is printed on the film.

3. A cling wrap film according to claim 1 or claim 2 suitable for wrapping a generally cylindrical or rolled object such as a newspaper, wherein the coating provides, in use, a visible indication of the direction in which separation of the outermost layer of the wrap from a contiguous inner layer may conveniently be commenced. 15

4. A cling wrap film according to claim 3 wherein the coating is applied to the film in the form of at least one longtitudinal strip or band covering a minor part of the width of the film and includes indicia which, in use, indicate the location of the cut edge of the film. 20

5. A cling wrap film according to claim 4 wherein the indicia indicate the location of the cut edge of the film by pointing towards the said edge and/or by the imperfect registration of overlapping layers. o

6. A cling wrap film according to any one of the preceding claims which is composed of stretch cling polyethylene which is adherent predominantly on one side. stat/cinoaks,/sp.aiprv.aus.chattomg. 17.6 10

7. A process of manufacturing a cling wrap film as defined in any one of the preceding claims which comprises continuously extruding the film from a melt in tube form, flattening the tube to produce a layflat tube which is passed to a flexographic printing press where each outside surface of the layflat tube is printed with one or more bands of print/release in the chosen pattern, and splitting the layflat tube to form two sheets of film which are rolled separately.

8. A process according to claim 7, wherein before it reaches the printer, the film is subjected to a corona discharge treatment applied to location of the strip or band which is to receive the coating.

9. A process of manufacturing a cling wrap film as 15 defined in any one of claims 1 to 6 which comprises continuously extruding the film from a melt to form a cast single sheet film, and then applying a print/release coating to the film, either in-line or off-line, in the Sform of one or more bands in the chosen pattern.

10. A process according to claim 9, wherein before the coating is applied, the film is subjected to a corona discharge treatment in the location of the strip or band which is to receive the coating. DATED THIS 18TH DAY OF JUNE 1997 AUSTRALIAN CHALLENGE (OPERATIONS) PTY LTD By its Patent Attorneys: GRIFFITH HACK Fellows Institute of Patent Attorneys of Australia staff/ieona/keep/speci/cap.aus.challenge 18.6