Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
  • G09F3/08—Fastening or securing by means not forming part of the material of the label itself
  • G09F3/10—Fastening or securing by means not forming part of the material of the label itself by an adhesive layer
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
  • G09F3/02—Forms or constructions

Definitions

• the invention relates to self adhesive labels made from polymeric sheet material.
• the general object of the invention is to provide a self adhesive label which is relatively thin but which has sufficient strength to enable it to be readily dispensed by automatic label dispensers.
• the label of the invention can be supplied in rolls or in sheets.
• the label is inexpensive in relation to other plastic labels, and has a superior print surface.
• Pearlized polypropylene labels have been printed by various self adhesive label printers with little or no success.
• the invention adds a laminate to the face stock which overcomes all the disadvantages of the face stock, making it a commercial alternative to paper and a cost advantage to known plastic labels.
• the present invention provides a self adhesive label comprising a first layer of polymeric material, said first layer being printed on one face and having adhesive material on its other face, the first layer having a thickness in the range from 15 to 80 microns, and a second layer of polymeric material laminated to said one face of the first layer, said second layer being transparent and having a thickness in the range from 20 to 50 microns.
• the polymeric material of the first and second layers comprises polypropylene or polyethylene.
• the label includes a removable backing sheet which is removably adhered to the adhesive matarial on said one face of the first layer, the first layer and backing sheet comprising a standard self adhesive construction.
• a silicon release layer is located between the backing sheet and the adhesive material on said one face of the first layer.
• the silicon release layer is preferably applied to one face of the backing sheet.
• the first layer of polymeric material is 25 to 30 microns thick.
• the self adhesive labels are supplied in roll form, it is customary to remove the extraneous portions of the first and second layers between adjacent labels so that the back sheet forms the continuous web of the roll.
• the gaps between adjacent labels can cause embossing marks on adjacent or opposite labels.
• the effect is also more apparent with irregular shaped and circular labels. It follows that in order to reduce this effect, it is preferable to use the thinnest commercially available materials, subject to those materials having sufficient strength. It is also preferred that the rolls be wound loose on cores of at least 75m.n diameter.
• the second layer of polymeric material is 35 microns thick.
• the second layer is laminated to the first layer by means of an adhesive or bonding agent, preferably a u.v. activated adhesive agent.
• the most effective adhesive agent is a vinyl primer which is normally used to treat vinyl sheet material in order that it may be successfully printed. These materials are not normally used with polypropylene or polyethylene sheets.
• the vinyl primer may comprise a urethane acrylate resin system comprising acrylate resins diluted in diacrylate and triacrylate monomers.
• the primer preferably includes photo-initiaters and photo-activators such as benzophenone, benzoin ethers, amino-benzophenones, and tertiary amines.
• the primer is preferably composed of solids and does not contain solvents cr volatiles.
• the bonding agent may comprise a polyester acrylate resin system which has similar photo-initiaters and photo-activators and again doer not include solvents or volatiles.
• the adhesive or bondirg agent is preferably applied in a thin layer to the second layer of polymeric material.
• the thickness of the adhesive or bonding agent is comparable to the thickness of the ink which is used for the printing on the first layer of polymeric material.
• Normally analine inks which are solvent based, are used when printing en polypropylene sheet material. Surprisingly, it has been found that it is possible to use u.v. activated inks of the type which are normally used on paper for printing on the first layer of polymeric material.
• the inks preferably include activaters to give better keying and faster curing.
• One suitable ink is "Flash Dry U.V. Ink" made by Toyo.
• the printing can be carried out on a more or less conventional label printing machine which has some modifications made to it including u.v. driers and a corona discharge unit for treating the first layer prior to printing.
• Figure 1 is a fragmentary view showing the construction of the adhesive label of the invention
• Figure 2 is a schematic view showing part of the eguipment used in forming the labels of the invention.
• Figure 3 is a schematic view showing part of a modified arrangement.
• Figure 1 illustrates a self adhesive label 2 constructed in accordance with the invention. The thicknesses of the various layers are not to scale. It comprises a face stock layer 4 which is preferably made of transparent or pearlized polypropylene (biaxially oriented or cast) .
• Pearlized polypropylene is a micro-voided cavertated structure with a pearlized appearance.
• White pigment such as titanium oxide can be added to make the pearlized layer white.
• an outer layer of white polypropylene can be formed on the pearlized structure.
• a further alternative for the material of layer 4 is a transparent film polypropylene which has been metallized on the side which is not printed on.
• the first layer 4 is in the range from 25 to 80 microns thick. The preferred thickness however is 25 microns.
• the layer 4 has an adhesive layer 6 bonded to its underside.
• a peel-off backing layer 8 with a silicon release layer 10 is adhered to the layer 6 in the usual way. It will be appreciated that the layers 4, 6, 8 and 10 form a standard self adhesive construction.
• the upper surface 12 of the layer 4 is printed using u.v. inks as described.
• the printing may be carried out on a KOPACK rotary letter press machine to which has been added a corona treating unit for treating the upper surface 12 of the layer 4 prior to being printed by the printing heads of the machine.
• the corona unit may comprise a GX-20 SHERMAN machine operating at a setting of 38 to 40 dyne and a nominal output power of 2kw. This is suitable for operating at a running speed of 50 to 60 metres per minute.
• the corona treatment of the surface 12 enables much better keying of the ink to the surface.
• a u.v. drier is added to the KOPACK printer in order to substantially dry the ink on the surface 12 as it leaves the printing head.
• the composite layer is then completed by laminating a top layer 14 of transparent polypropylene thereto.
• the top layer 14 is laminated to the layer 4 by means of an adhesive or bonding agent 16.
• the adhesive preferably comprises a thin layer of u.v. activated adhesive.
• the adhesive preferably comprises a vinyl primer or polyester acrylate resin system containing photo-initiaters and photo-activators.
• the underside surface 18 of the layer 14 preferably has been treated by a corona discharge so as to improve adhesion of the agent 16 thereto.
• the layer 14 comprises polypropylene or polyethylene, it is often supplied by manufacturers in rolls which have been corona treated so it is unnecessary to treat the material again prior to lamination.
• the top layer 14 is preferably in the range 20 to 50 microns. The preferred thickness however is 40 microns. After the layers 4 and 14 have been laminated together, they will normally remain in this condition.
• the transparent layer 14 adds strength to the label and protects the printing on the top surface 12 of the layer 4 .
• the label of the invention is guite rigid and scuff resistant compared to known 60 micron pearlized labels without laminate. It is possible to use polymers and copolymers other than polypropylene.
• one or other of the layers 4 or 14 may comprise polyethylene, the stock layer 4 being transparent or opague and the top layer 14 being transparent. Where one or both of these layers is polyethylene, the thicknesses and treatments of the two layers are the same as described above.
• FIG. 2 diagramatically shows a simple arrangement for laminating the labels of the invention.
• the self adhesive feed stock 20 is applied to an impression drum 22.
• the self adhesive feed stock comprises the first layer 4, backing layer 8 with the adhesive 6 and self-release layer 10.
• the outer surface 12 of the layer 4 has been printed and u.v. dried as described above.
• the arrangement includes a supply roll 24 of the second layer 14.
• the layer 14 passes about a forming roller 26 which in turn cooperates with an adhesive printing roller 28.
• the drum 22 and roller 26 are both driven such that their surface speeds are the same.
• the adhesive printing roller 28 applies a thin layer or film of adhesive 16 to the second layer 14. Once the adhesive has been applied, the two layers are pressed together between the forming roller 26 and the drum 22 so as to permanently laminate the layers together.
• FIG. 3 illustrates an alternative arrangement for laminating the labels of the invention.
• the printed self adhesive feed stock 20 is fed between an upper pair of rollers 30 and 32 which are both driven in unison by gears (not shown).
• the roller 32 applies the layer or film of adhesive 16 to the printed outer surface 12 of the layer 4.
• the feed stock then passes between a lower pair of rollers 34 and 36 and the second layer 14 is pressed into firm engagement with the layer of adhesive.
• the roller 34 is driven in synchronism with the rollers 30, 32.
• the roller 36 is friction driven by virtue of its contact with the layer 14.
• the two layers then pass to a ⁇ .v. drier (not shown) for curing of the adhesive layer 16.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Laminated Bodies (AREA)
• Adhesive Tapes (AREA)

Applications Claiming Priority (4)

Publications (2)

Family

ID=25643504

Family Applications (1)

Country Status (3)

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Family Cites Families (4)

• 1989
  • 1989-07-05 NZ NZ22984389A patent/NZ229843A/xx unknown
  • 1989-07-06 WO PCT/AU1989/000289 patent/WO1990000788A1/en not_active Application Discontinuation
  • 1989-07-06 EP EP19890907637 patent/EP0424418A4/en not_active Withdrawn

Non-Patent Citations (2)

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