AU720751B2 - Improved manufacturing method and apparatus for adhesive labels - Google Patents

Description

-1- P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventors: Address for service ASHLEY LEACH ASSOCIATES PTY LTD Ashley Leach and Ralph Skendzic in Australia: CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia Invention Title: IMPROVED MANUFACTURING METHOD AND APPARATUS FOR ADHESIVE LABELS Details of Associated Provisional Application: P02463 filed 20 September 1996 The following statement is a full description of this invention, including the best method of performing it known to us -2- INTRODUCTION TO INVENTION This invention relates to adhesive labels and in particular to partially transparent plastic labels having a region of solid colour bonded foil formed thereon and to an improved method of continuous batch production of such labels.

BACKGROUND TO INVENTION The advantages of solid colour labels, particularly for use in the labelling of cables, is described in Australian Patent No. 648177, the disclosures therein which are herein included by reference.

The continuous batch production in accordance with Australian Patent No.

648177, whilst providing substantial improvements over alternative techniques, has certain limitations, particularly insofar as the heating plate used to apply heat and pressure to the foil is concerned.

To date, the method of manufacture involves the following steps of advancing to a print station a support sheet having a label sheet adhering 15 thereto, the label sheet being capable of being peeled from the support sheet with adhesive remaining on the rear face of the label sheet; introducing a printing foil so as to closely overlie the label sheet at the print station; advancing a heated plate at the print station so as to apply heat and pressure at selected sites or in a desired pattern or configuration to the foil to press the foil against the label sheet so as to 20 bond foil to the label sheet selectively, so as to form a desired pattern or configuration of bonded foil to label sheet; and retracting the heated plate and :removing unbonded foil; the support and label sheet with bonded foil pattern sheet being withdrawn from the print station after the retraction of the plate.

However, the requirement of advancing and retracting the heating plate reciprocally back and forth to repeatedly contact the foil and label sheet imposes limitations on the speed at which the process can be run, in addition to introducing a large area of heat to the label product. Further limitations include quality and finish limitations, restricted adhesives available for use and general limitation of the type and range of materials available for use in making up the labels. Accordingly, the prior art processes introduce many limitations to the labels per se and process of MAW:PP:#23338.CAP 12 September 1997 -3manufacture.

In order to increase the efficiency and speed of the process, it would be desirable to replace the reciprocating heating plate with a rotating heating roller.

Such an improvement would also allow a greater range of label sheet materials to be used.

OBJECT AND STATEMENT OF INVENTION One object of the invention is to provide an improved method of manufacturing adhesive labels.

Accordingly, in one aspect the invention provides a method of manufacturing adhesive labels as a continuous batch product the steps of: advancing to a print station; a support sheet having a label sheet adhered thereto, the label sheet capable of being peeled from said support sheet with adhesive remaining on the rear face thereof; introducing a printing foil so as to closely overlie said label sheet in the vicinity of said print station wherein said print station comprises a heated stamping cylinder adapted for co-operative rotation in the direction of and in juxtaposition to said label sheet and printing foil overlie so as to apply heat and pressure at selected sites or in a desired pattern or configuration to said foil so as to press the foil against said label sheet and selectively bond said 20 foil to said label sheet, so as to form a desired pattern or configuration of foil bonded to said label sheet, advancing said label sheet beyond said print S. station, removing unbonded foil and withdrawing the support and label sheet "I ~with bonded foil pattern from said print station.

The heated stamping cylinder is provided with an integral heating means adapted to mirror the desired pattern or configuration of bonded foil and an appositionally placed idling roller adapted for sandwiching said label sheet and printing foil.

The support sheet carrying the adhesive label sheet which is initially fed to the print station may be either a support web or an individual cut sheet. In the case of a support web, the web for example may be fed from a roll on a substantially MAW:PP:#23338.CAP 12 September 1997 -4continuous basis. The support sheet may for example be a paper sheet, provided with a coating if desired in order to enable the label sheet to be peeled from the support sheet leaving adhesive on the label sheet. The adhesive label sheet is preferably transparent or translucent so that areas of the label sheet to which foil is not applied remain clear or translucent. For example the label sheet may be low gloss frosted clear plastics material of the general kind used in adhesive tape rolls used as office stationery.

The introduction of the printing foil as so to closely overlie the label sheet at the print station may comprise advancing a continuous backing web on which the foil is carried, e.g. feeding a backing web from a supply roll. The foil may be of any desired colour, and preferably is a solid colour foil. The material of the foil may be a plastics material which is adhesive or is intimately bonded by its own composition to the backing web.

*oo* Preferably the heated stamping cylinder is rotated in contact with the backing 15 web on the opposite face to the foil so as to press the foil against the label sheet as a sandwich against the idling roller. The stamping cylinder provides the required pattern or configuration of the foil to be applied to the label sheet. The stamping cylinder may be of any suitable material and construction and it may for example comprise a magnesium plate or brass so as to have a suitable heat capacity and being 20 relatively easily worked to provide the required pattern.

Preferably the stamping cylinder is heated to a temperature at which there is softening of the foil and/or the material of the label sheet so as to thereby achieve intimate bonding or fusion of the foil in the required pattern or configuration to the label sheet. The strength of bonding of the foil to the label sheet is preferably greater than the adhesive force between the foil backing web and the foil so that upon retraction of the plate and removal of the foil backing, the foil pressed against the label sheet will remain bonded to the label sheet.

After the support sheet is processed by the print station a waste border portion of the label sheet may be removed. For example, the border portion may comprise edging around each of the labels and/or along the edges of the label sheet which is MAW:PP:#23338.CAP 12 September 1997 desirably removed to enable a user to easily grasp a corner of the remaining adhesive label material and peel the label from the support sheet. The removal of the border portion may be achieved by peeling the border portion away from the advancing support sheet and for example rolling the border portion around a rotating take-up roll.

Prior to, or if desired, after the print station individual label shapes may be cut through the thickness of the label sheet, but not through the support sheet so that individual labels of the desired shape are formed for individual removal from the support sheet. If desired, the support sheet may also be perforated to enable the sheet to be torn along the perforation lines to leave smaller support sheets to which a number of adhesive labels are adhesively secured. Furthermore, for continuous stationery of the kind used for computer printers the support web may have holes punched among it on opposite edges to enable use of the support web and adhesive labels thereon as feed stationery for a computer printer, e.g. for computer controlled 15 printing of mater onto the solid colour foil portions of the labels. Such cutting and V perforating can be performed by rotating cylinders with accompanying idling cylinders.

By virtue of the improved method, the label sheet can be now made of a selection of materials including: Polyvinyl chloride Polyolefin S. Polyethylene Polypropylene Polyester For example, the improved method of the invention allows the characteristics of Polyethylene to be utilized to full advantage in the preparation of adhesive labels whereby adhesive labels manufactured from Polyethylene in accordance with the method of the invention, provide acceptable clarity, good flexibility, acceptable weight, acceptable thickness, acceptable strength, good environmental factors and acceptable temperature properties.

MAW:PP:#23338,CAP 12 September 1997 -6a.

a.

The choice of label sheet material is guided by the preferred specifications of the available materials which are as follows: Material Specifications PVC Weight: 45 to 130 grams/m 2 Thickness: 60 120 micron Tensile Strength MD: 15 to 30 N/cm CD: 15 to 30 N/cm Elongation: MD: 150 to 200% CD: 150 to 200% Surface Tension: N/A Polyolefin Weight: 70 to 120 grams/m 2 Thickness: 60 120 micron Tensile Strength MD: 15 to 30 N/cm CD: 15 to 30 N/cm Surface Tension: >30 Dynes/cm Polyethylene Weight: 70 to 120 grams/m 2 Thickness: 60 120 micron Tensile Strength MD: 15 to 30 N/cm CD: 15 to 30 N/cm Polypropylene Weight: 20 to 110 grams/m 2 Thickness: 30 100 micron Tensile Strength MD: 30 to 170 N/cm CD: 80 to 340 N/cm Surface Tension: >39 Dynes/cm Polyester Weight: 10 to 120 grams/m 2 Thickness: 18 125 micron Accordingly, in another aspect, the invention provides an improved adhesive label as hereinbefore described characterised by having a label sheet made of any one of PVC, polyolefin, polyethylene, polypropylene or polyester. Most preferably, the label sheet has specifications as hereinbefore described.

Any combination of the aforesaid materials can be used but polypropylene is particularly preferred.

The printing foil may be adapted to receive printing ink and is preferably at least partially opaque and may comprise a laminate of: MAW:PP:#23338.CAP 12 September 1997 -7- Carrier film chosen from polyester, paper, cellulose, polypropylene, acetate, polythene, etc., and is used as the support for the remaining layers of the foil; (ii) Release coating applied thereto which allows the colour coat to be released when heat is applied. The release coating is chosen (thickness, type, slow, fast, etc) to suit the application at hand; (iii) Colour coating the actual pigment for stamping; and (iv) Size coating performing the bonding action.

The printing foil is most preferably KURZ V911 white foil or the equivalent which is heat and pressure fused onto the label sheet.

The adhesive used for laminating the label sheet to the support sheet is preferably an acrylic resin having the following properties: 9 .9 .c 6.

9.

6 99 9 Material Specifications Adhesive Adhesion FTM1: >4 Initial Loop Tack FTM9: >4 N/625mm 2 Cohesion (1 Kg/625 mm 2 >20 mins Application Temp: >-20 0

C

Temp Resistance Minimum Temp: >-60 0

C

Max Temp: >40 0

C

(applied to substrate 1 hour) Transparent, acrylic, UV stabilised adhesive. Does not discolour with age or temperature. Must resist high levels of plastizers in PVC.

The label sheet layer of the laminate may be segmented with a series of cuts or indentations to effect a backing sheet having a series of discrete labels removable therefrom.

MAW:PP:#23338.CAP 12 September 1997 -8- The support sheet is most preferably used having the following specifications: Backing (support) Weight: 40 to 180 Grams per m 2 material Thickness: 45 to 160 micron Tensile Strength MD: 40 to 120 N/cm CD: 20 to 60 N/cm Burst: 25 N/cm 2 The support sheet preferably has both push and pull feed capacity through computer printers.

The application of the printing foil may be discretionary with only part of the label sheet of a given discrete label being overlaid with the printing foil in order to effect a label having partial clear PVC, polyolefin, polyethylene, polypropylene or 10 polyester as required and partial opaque printing foil.

The printing foil may also be applied in the form of a symbol, word or other instructing format.

In its most preferred form the labels are adapted for marking cabels and have a rectangular form with a portion of the clear label sheet overlaid with printing foil 15 such that instructing information may be applied to the foil whence the label may be folded around a cable and back upon itself such that the clear remainder of the label sheet folds back over the foil to fully protect the instructing information.

In another aspect, the invention provides an improved apparatus for manufacturing adhesive labels comprising a print station having a heated stamp 20 cylinder, a means for delivering a continuous supply of printing foil and support sheet material simultaneously over said heated stamp cylinder characterised in that said heated stamp cylinder is rotatable and adapted to remain in constant contact with said printed foil and support sheet.

Possible and preferred features of the present invention will now be described with particular reference to the accompanying drawings. However it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting the script of the invention.

12 September 1997 MAW:PP:#23338.CAP -9- Figure 1 is a schematic diagram of an apparatus for continuously manufacturing labels according to the present invention.

Referring to Figure 1, the method of the invention is performed with the use of a label printing apparatus as is schematically drawn. The apparatus comprises a print station which consists of a number of rollers which are adapted to bring together a support sheet having a label sheet adhered thereto and a printing foil in a manner where the support and label sheets can be sandwiched, together with the printing foil, between a heated stamping cylinder 1 and the stamping idle cylinder 4. In addition, the mechanism comprises a series of rollers and take up reels which effect the transfer of the adhesive labels once formed at the print station.

The apparatus comprises a label support sheet supply reel 7 which holds the bulk label sheet and support sheet laminate. The label and support sheet laminate 2 passes across a pair of guide runners 14 through the heated stamping cylinder 1 and its co-operative stamping idle cylinder 4 then passing on through a perforation 15 and socket hole cutting cylinder 10, then onto a die cutting cylinder 12 and finally onto the label and support sheet up take reel 8. Simultaneously, the printing foil 3 is held and released from a printing foil supply reel 5 and passes over two guide runners 15 passing between the heated stamping cylinder 1 and the stamping idle cylinder 4 and is then taken up at the printing foil up take reel 6. The precise 20 juxtaposition of the label and support sheet guide mechanisms and the printing foil guide mechanisms are co-ordinated to pass between the heated stamping cylinder and its idle cylinder so as to allow the heated stamping cylinder to bond the printing foil •0 o to the label sheet. Once the bonding of the printing foil to the label sheet has been effected, the label support sheet laminate and the printing foil sheet go separate ways with the printing foil sheet with the unbonded foil intact being taken up by the printing foil up take reel 6 whilst the support and label sheets which now have the printing foil selectively bonded thereto pass on between a perforation and socket hole cutting cylinder 10 and its corresponding perforation and socket idle cylinder 11 which effect the required perforations to the label sheet. The label and support sheet then passes through the die cutting cylinder 12 and its corresponding die 12 September 1997 MAW:PP:#23338.CAP cutting idle cylinder 13 which effect the requisite cutting of the label sheets. The label sheet waste material left over after the die cutting process then is taken up by the waste up take reel 9 with the remainder of the support sheet and the attached label sheet, as is required for the final product, being taken off and stored in the label sheet up take reel 8.

Referring now to the separate components of the process of the invention, the stamping process requires the provision of a foil path for the printing foil material, the printing foil material is supplied from the supply reel 5 and circulates around the guide runners to be taken up by the printing foil up take reel 6. The new foil should pass between the label sheet material and the heated stamping cylinder 1 and should also be driven at a speed that will ensure the correct transfer of the foil to the label sheet material. The driving speed of the foil path is preferably driven at the same rate as the driving speed of the label and support sheet material. The label and "'-"support sheet material should have a supply reel 7 and an uptake reel 8 and should be arranged to pass underneath the foil as it passes through the printing station and above a hardened roller or stamping idle cylinder 4. The combined use of the heated stamping cylinder and its appositionally placed idle cylinder provide the preferred stamping mechanism. The drive speed of the label and support sheet material can be adjusted for optimum quality and completed labels. The heated 20 stamping cylinder must be heated in a manner to effect the welding of the printing foil to the label sheet. The pressure applied by the heated stamping cylinder to the printed foil and label sheet is ensured by the urging of the heated stamping cylinder onto the hardened stamping idle cylinder 4. The printing station so described form the heart of the apparatus of the invention, however, other operations are required in order to finalise the production of the adhesive labels. The perforations may be added at any point in time with the use of a perforation and socket hole cutting cylinder appositionally placed in relation to a perforation and socket idle cylinder between which the label sheet and support sheet pass. Similarly sprocket holes are preferably provided in order to allow the labels to pass through the end user machine and these are created along with the perforations.

MAW:PP:#23338.CAP 12 September 1997 -11- Die cutting is also performed at some stage in the operation of the invention and it defines the shape of the label and the required waste areas. The die cutting process is a matter of applying selective pressure to a die cutting cylinder or roller 12 which has the shape of the required label. The die cutting along with all the other perforating and stamping operations are preferably performed in a synchronised fashion and at a constant speed. The waste removal preferably occurs at some stage in the process whereby the excess label material is removed from the label sheet in order to provide a support sheet having the labels clearly formed thereon and available for removal as required by the end user.

The apparatus and method of the invention provide a highly efficient precise speedy method for producing the adhesive labels of the invention; in particular, the apparatus and method of the invention provide a continuous motion system using rollers as the various stamping and forming blocks allowing the motion to run continuously at a speed that can be easily adjusted in order to monitor the quality 15 of the stamping process in accordance with the details required for any particular run. The rotary heated stamping cylinder is in contact with the printing foil and support and label sheet material at any particular point for only a very short period of time unlike the more conventional stamping methods. The very short contact time results in a cleaner, even, consistent and better quality opaque section. The continuous motion of the apparatus and method of the invention provides for the production of completed labels at a far higher rate per hour then was previously attainable. Furthermore, the apparatus of the invention insofar as it exposes only a very small section of the materials to the heat required for bonding at any given .i point in time minimises the damage and degradation to the materials caused by the intrinsic heat required in the process. The apparatus and method of the invention whilst being described with reference to the particular embodiment in Figure 1, is not limited to the use of this particular arrangement of rollers and cylinders. Other variations of the invention could provide the combined stamping and perforating operations and/or a combination of the die cutting and waste removal operations.

Similarly it is possible to perform all the operations of the invention completely independently depending on the particular requirements of the products and the machines available.

MAW:PP:#23338.CAP 12 September 1997

Claims (2)

12- The claims defining the invention are as follows: 1. A method of manufacturing adhesive labels as a continuous batch product comprising the steps of: advancing to a print station; a support sheet having a label sheet adhered thereto, the label sheet capable of being peeled from said support sheet with adhesive remaining on the rear face thereof; introducing a printing foil so as to closely overlie said label sheet in the vicinity of said print station wherein said print station comprises a heated stamping cylinder adapted for co-operative rotation in the direction of and in juxtaposition to said label sheet and printing foil overlie so as to apply heat and pressure at selected sites or in a desired pattern or configuration relative to said foil so as to press the foil against said label sheet and selectively bond -said foil to said label sheet, so as to form a desired pattern or configuration of foil bonded to said label sheet, advancing said label sheet beyond said print station, removing unbonded foil and withdrawing the support and label sheet i with bonded foil pattern from said print station. 2. A method according to claim 1 wherein said heated stamping cylinder is provided with an integral heating means adapted to mirror the desired pattern or configuration of bonded foil and an appositionally placed idling roller adapted for sandwiching said label sheet and printing foil. 3. A method according to claim 2 wherein said heated stamping cylinder is rotated in contact with a backing web positioned on the opposite face to said foil so oe as to press the foil against the label sheet as a sandwich against said idling roller. 4. A method according to any one of claims 1 to 3 wherein said stamping cylinder is heated to a temperature at which there is softening of the foil and/or the material of the label sheet so as to thereby achieve intimate bonding or fusion of the foil in the required pattern or configuration to the label sheet. MAW:PP:#23338.CAP 12 September 1997 A method according to claim 4 wherein the strength of bonding of the foil to the label sheet is made greater than the adhesive force between the foil backing web and the foil so that upon retraction of the plate and removal of the foil backing, the foil pressed against the label sheet will remain bonded to the label sheet. 6. Bonded foil adhesive labels manufactured in accordance with the method of any one of claims 1 to 5 comprising a support sheet having a label sheet adhered thereto characterised in that said label sheet is made of Polyolefin. 7. Bonded foil adhesive labels manufactured in accordance with the method of any one of claims 1 to 5 comprising a support sheet having a label sheet adhered thereto characterised in that said label sheet is made of Polyethylene. 8. Bonded foil adhesive labels manufactured in accordance with the method of any one of claims 1 to 5 comprising a support sheet having a label sheet adhered thereto characterised in that said label sheet is made of Polypropylene. 9. Bonded foil adhesive labels manufactured in accordance with the method of any one of claims 1 to 5 comprising a support sheet having a label sheet adhered thereto characterised in that said label sheet is made of Polyester. An improved apparatus when used in accordance with the method of any one of claims 1 to 5 comprising a print station having a heated stamp cylinder, a means for delivering a continuous supply of printing foil and support sheet material simultaneously over said heated stamped stamp cylinder characterised in that said heated stamp cylinder is rotatable and adapted to remain in constant contact with said printed foil and said support sheet. 11. A method according to any one of claims 1 to 5 substantially as hereinbefore described with particular reference to the examples. 12. A label sheet according to any one of claims 6 to 9 substantially as hereinbefore described with particular reference to the examples.

13. An apparatus in accordance with claim 11 substantially as hereinbefore described with particular reference to the examples. DATED: 13 April 2000 CARTER SMITH BEADLE Patent Attorneys for the Applicant: AASHLEY LEACH ASSOCIATES PTY LTD 13 April 2000