RU2512867C2 - Method of label application on article - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: application of label on article with surface that features at least one complex curvature said label having: (i) shrinkable film with inner and outer surfaces, machine and transverse directions; (ii) contact glue ply on film inner surface; (iii) note here that said label has first edge and contact zone. Contact glue ply is brought in contact with article in label contact zone. Then, said label is heated and pressed in direction from contact zone towards first edge for it to be glued to article and shrunk to take up the article curvature. Note here that heat and pressure are brought about by at least one hot air squeegee. The latter comprises hot air source, flow control mechanism and at least one squeegee slit with hot air. Note also that shrinkable film features limit shrinkage S in at least one of machine or transverse direction making at least 10% at 90°C. Note that shrinkage in another direction makes S±20%.

EFFECT: better adhesion.

22 cl, 25 dwg, 1 tbl

Description

FIELD OF THE INVENTION

The present invention relates to self-adhesive shrink labels. In particular, the invention relates to self-adhesive labels having the ability to adhere well to containers having a complex shape, and more particularly, the invention relates to methods for applying such labels to products.

State of the art

Containers or bottles are usually labeled with labels containing information, for example, about the supplier of the container or the contents of the container. Such containers and bottles have a wide variety of shapes and sizes and are used to place materials of various types in them, for example, detergents, chemicals, hygiene products, motor oil, drinks, etc.

It is known to use polymeric film materials and film substrates for printing as labels in various fields. The need for polymer labels is increasing, especially the need for transparent polymer labels, when used on decorative glass and plastic containers it is possible to create the impression of the absence of the label itself. Paper labels do not allow the container and / or its contents to be seen. Transparent polymer labels improve the visual aesthetics of the container and thereby the product, and their use to improve the appearance of containers expands significantly faster than paper labels, as consumer goods companies are constantly striving to improve the appearance of their product. In addition, polymer films have good mechanical properties, for example, tensile strength and wear resistance.

Traditionally used self-adhesive (PSA - from the English. Pressure sensitive adhesive) labels are usually difficult to glue smoothly to containers having curved surfaces and / or surfaces of complex shape, avoiding wrinkles, wrinkles and peeling. Typically, the size of a self-adhesive label is limited so that it is no closer ^than _1/4 inch (6.4 mm) from the edge (beginning) of the curvature of the container or product. Shrink containers of this type typically use shrink labels. The method of applying labels includes processes and methods during which tubes or cuffs are prepared from heat-shrinkable film, which are put on the container and heated to shrink the film so that it takes the size and shape of the container. Alternatively, the container is completely wrapped with a shrink label during the process, when the shrink film is applied to the container directly from a continuously unwound roll of film material, and after heating the wound label wraps around the container. However, when applying labels to bottles of simple or complex shapes, or further working with them, label defects may occur. Badly applied labels contribute to increased waste or the need for additional processing, the cost of which can be high.

The present invention provides a self-adhesive label that can be applied to containers and products with a complex shape and curvature with a reduced amount of material and at a lower cost than when using shrink cuffs for the label or wrapping with such material. In addition, the labels proposed in the present invention allow the user to expand the area with the inscriptions and graphics of traditional self-adhesive labels on containers and products having a complex shape and / or complex curvature.

Disclosure of invention

The present invention discloses a method of applying a label to an article, comprising providing an article with a surface having at least one complex curvature, and a label with a first edge and a contact zone having a heat-shrinkable film with inner and outer surfaces and a layer of contact adhesive on the inner surface of the film in contact with the product layer of contact adhesive in the contact zone of the label and the simultaneous exposure to heat and pressure through at least one node of the squeegee of hot air containing th source of hot air, a flow control mechanism and at least one squeegee gap with the hot air at the label in a direction from the contact region to the first edge for adhering it to the article and subjecting the label shrinkage for making products of its curvature. Also in the method, a label may be used having a center and a second edge, on the opposite side from the first edge of the side, and a contact area located near the center or in the center of the label. In addition, the method can use a label having a second edge on the opposite side from the first edge of the side, and a contact area located near the second edge of the label. A hot air squeegee assembly may also be used comprising at least two hot air squeegees that rotate outward from the center of the label to the first and second edges to adhere the label to the product. Additionally, they can act by heating and pressure on the label from the center to the first edge of the first doctor blade with hot air, and the second doctor blade by applying heat and pressure to the label from its center to the second edge. In the method, the product can also be rotated about 180 ° before being exposed to heat and pressure on the label with a second doctor blade. The method may also use a label provided with a release liner glued to the adhesive layer and separate the liner from the label before bringing the label into contact with the product. The label can be heated to at least 40 ° C. A film may also be used, which is a film of polyester, polyolefin, polyvinyl chloride, polystyrene, a lactic acid polymer, copolymers or mixtures thereof. In addition, a polyolefin film may be used. Additionally, you can use a film that is multilayer with an inner and at least one outer layer. The method may use a film having a machine direction and a stiffness therein of at least 5 mN. The method may use a label containing a print layer between the film and the adhesive layer, the film being transparent. The method may use a label further comprising a print layer on the outer surface of the film. A label may also be used that further comprises a protective layer covering the print layer. In addition, an adhesive layer containing an emulsion adhesive can be used. An adhesive layer containing hot melt adhesive may be used. An adhesive layer containing a solvent based adhesive may be used.

The method involves performing a continuous layer of contact adhesive. In the method, a layer of contact adhesive can be made on a stencil substantially covering the inner surface of the film. The method can use a film with machine and transverse directions, while the film can be made with ultimate shrinkage S in at least one direction of at least 10% at 90 ° C, and in the other direction S ± 20%. Also in the method, they can additionally heat the film after simultaneous exposure to heat and pressure by the squeegee assembly.

Brief Description of the Drawings

Figure 1 presents a front view of the container on which the label is applied in accordance with the present invention, in comparison with the known self-adhesive labels.

Figure 2-5 presents the image of the container with the label before and after exposure to heat on the label.

Figure 6-9 presents embodiments of containers of complex shape with complex curvature, which is applied to the label in accordance with the present invention.

10 and 11 are front views of embodiments of containers of irregular shape.

On Fig shows a General view of a part of the product with a label having complex curvature.

13-16 is a schematic illustration of a method of applying a label to an article with complex curvature.

17 and 18 are a schematic illustration of a method of applying a label to an article using a movable cross member.

19 and 20 are schematic views of an air squeegee assembly for simultaneously applying heat and pressure to a label.

On Fig.21-25 shows schematic views of a method of applying a label to an article using a group of slots of an air squeegee.

The implementation of the invention

Self-adhesive labels are presented, the use of which allows to improve the appearance of containers and products with labels, due to a good fit to the surface of the container or product, and an increased image area. Currently, end users and product developers must make changes to product designs to adapt them to the restrictions imposed by existing product design technologies. Labels proposed in the present invention provide developers with more freedom in creating the design of products with an attractive presentation and carrying more information.

Containers and products with complex curvature usually need to be completely wrapped in shrink film for labeling or product design. Labels proposed in the present invention make it possible to cover a surface of complex curvature with a label without having to wrap the entire product. Such partial coverage of the product affects the cost of the product, as well as its appearance. Conventional self-adhesive labels cannot be applied to containers and products without the appearance of unwanted wrinkles and wrinkles on the label. Under the "folds" refers to the lifting of the label material above the surface of the product on which it is applied due to the accumulation of excess material.

Labels proposed in the present invention provide significant manufacturing advantages over conventional shrink labels. For example, the self-adhesive shrink labels proposed in the present invention allow the use of traditional printing and recycling technologies, for example, foil stamping and hot stamping. While the manufacture of conventional shrink labels involves intaglio printing, the labels of the present invention can be embossed on the surface to provide high-quality color, clarity and texture to the printed image. Printing film labels can be carried out by methods of water flexography, UV flexography, UV letterpress, UV screen printing, solution engraving and hot stamping on foil.

Self-adhesive labels include a heat-shrinkable polymer film having an inner surface and an outer surface, and a machine (longitudinal) direction and a transverse direction; and a layer of contact adhesive on the inside of the heat-shrinkable film. Shrink film has uniform shrinkage in both machine and transverse directions. The ultimate shrinkage (S) of the film in at least one direction is at least 10% at 90 ° C, and the ultimate shrinkage of the film in the other direction is S ± 20%. An example of uniform shrinkage is machine shrinkage of 40% at 105 ° C with corresponding shrinkage in the transverse direction of 40% ± 20%, or in the range from 20% to 60% at 105 ° C. In one embodiment, the ultimate shrinkage (S) is at least 10% at 90 ° C, and in the other direction, the shrinkage is S ± 10%. As used herein, the term “ultimate shrinkage” refers to the maximum shrinkage that a film can provide at a particular shrink temperature as measured by ASTM Method D 1204.

In the present invention, labels are not prepared in the form of a cuff or tube of shrink material that envelops the entire product, or in the form of a label obtained by wrapping a shrink film around the product to form a seam at the junction of the ends of the label. The labels proposed in the invention can be of a wide variety of forms in accordance with the requirements of the container or product on which they are applied, which provides the container designer with greater freedom in choosing the container configuration and label design compared to existing self-adhesive labels, or with cuff-based labels from shrink material or shrink wrapping obtained. Labels can be cut into the desired shape by any known means, including, for example, die cutting and laser cutting. In one embodiment, the die-cut label is configured to take into account the shrinkage of the label and the shape of the product on which it is applied.

Since the label is characterized by a tight fit, the area of the inscription or graphics on the container with the label can be moved further to the edges of the container and on the surface of the container with complex curvature. Label size can be 10-30% larger than the size of a standard PSA label. In the present description, the term "complex curvature" means a surface on which there is no direction along which there would be no curvature. For example, the surface of a sphere or the surface of an ellipsoid has curvature in each direction and, therefore, has complex curvature. The cylinder, on the contrary, has a surface on which there is at least one direction along which there is no curvature. Thus, a simple cylinder does not have complex curvature.

Figure 1 shows an expanded image area of a self-adhesive shrink label in accordance with the present invention. A self-adhesive shrink label 12 is adhered to the bottle 10. Dashed lines 14 show the outer borders of standard self-adhesive labels. A standard (i.e. non-shrink) self-adhesive label cannot be used on bottle areas having a complex curvature 16 (the area between the inner dotted line and the outer solid line). When the label 12 is initially applied to the bottle 10, wrinkles and / or wrinkles may form around the label in areas of the bottle having complex curvature 16.

When a self-adhesive label is applied to the container, heat is applied as necessary to eliminate any defects in label application, such as wrinkles, raised edges and wrinkles. In one embodiment, in addition to exposure to heat, pressure and / or smoothing can be used to eliminate defects.

Figure 2-5 illustrates the presented label and the method of its application. In FIGS. 2 and 3, a label 12 including a shrink film with a continuous layer of contact adhesive applied thereon is applied to a container 10 having a complex curvature around the circumference of the container, and then smoothed. Heating does not affect the label. Label 12 goes to areas with complex curvature 16, where folds 18 are formed around the label perimeter 20. FIGS. 4 and 5 show the container with the label shown in FIGS. 2 and 3 after exposure to the label by heating. The folds 18 are removed, and the label 12 is adjacent to the surface of the container 10 of complex curvature near its perimeter 20 without any defects.

The product or container on which the label is applied may have various shapes and shapes. Suitable examples without limiting the invention include containers with or without lids, stationery boxes, lids, toys, electrical appliances, etc. The product or container may be made of any conventional polymer, glass, or metal, such as aluminum. Examples of suitable polymeric materials include high density polyethylene (HDPE - from English high density polyethylene), low density polyethylene (LDPE - from English low density polyethylene), polyethylene terephthalate (PET - from English polyethylene terephtalate), polypropylene (PP - polypropylene) , polyvinyl chloride, polycarbonate, nylon, fluorinated ethylene propylene, polystyrene, etc. The product or container can be manufactured by various known processes, for example, blow molding, injection molding, thermoforming, centrifugal casting, etc.

Examples of containers used include, for example, a bottle with a cap at the top of the bottle, an inverted bottle with a cap at the bottom of the bottle, a bottle with a pump-type spray valve or foam dispenser, a tube with a cap and a bottle with a cap.

The container or product may be transparent. In one embodiment, the container may be translucent. The translucent appearance can be obtained by treating a transparent container or product, introducing ingredients, for example, paints and pearlescent additives into the base polymer, using polypropylene and (or) polyethylene mixed with antireflective additives. The treatment includes, for example, surface treatment in the mold.

The container or product may include aesthetics, including, for example, texture, embossing, color, holograms, frost or matte effects, etc. The surface of the container or product can be treated before labeling. For example, the surface of a container or product may be flame treated or primed.

On each of Fig.6, 7 and 8 shows a container having a complex shape and complex curvature. FIG. 6 is a front view of a container 30a having a symmetrical, spherical shape, such that the container has a tapering concave region 32 at the top and a wider convex region 33 at the bottom. Typically, a shrink sleeve was used to apply the desired label to such a container. By means of the present invention, the self-adhesive shrink label 31 can be smoothly applied to the container 30a without visible label defects. 7 is a front view of a container 30b having an asymmetrical shape, where one side of the container has both a concave region 34 and a convex region 35, and the opposite sides are curved in a similar manner along the length of the container. When applying the label to the container 30b in a known manner, a sleeve of shrink material is put on the container to ensure that the label adheres to the surface of the complex shape of the container. A self-adhesive shrink label 31 can be applied to the container 30b to create a sufficient image area at a significantly lower cost label material. On Fig presents a front view of the container 30C, which is an inverted bottle with a cap 36 at the bottom and a label 31 attached to the front surface. Fig. 9 is a side view of the container 30c. The areas 37 within the dotted lines show the outer borders of standard self-adhesive labels that can be attached to the container. To design this container, which has a complex shape, two separate standard self-adhesive labels are required, since applying one standard single self-adhesive label will lead to the formation of defects such as wrinkles and wrinkles. Self-adhesive shrink label 31 can cover a significantly larger area, which provides more opportunities for the product designer.

Each of FIGS. 10 and 11 shows a container having a complex surface configuration. 10 is a front view of a container 40a having convex ribs 42c on one side of the container. On the opposite side, the container has a smooth surface. 11 is a front view of a container 40b having annular grooves 43 arranged along the length of the container. It should be noted that products of cylindrical shape having regions of complex curvature, for example, containers 40a and 40b, are not excluded from products falling within the scope of the claims of this application.

On Fig shows a schematic three-dimensional image of the part of the container on which the label was applied. The container 50 has a surface with complex curvature. Label 52 is applied to the container and covers part of the area with complex curvature. Line 54 shows the outer border to which conventional self-adhesive labels can be applied without creating defects on the label. Area 56 shows an expanded image area that can be obtained using the proposed labels, without the formation of defects, such as wrinkles, raised edges or wrinkles.

Shrink film

Polymer films suitable for creating labels proposed in the present invention have the property of uniform shrinkage. The property of uniform shrinkage makes it possible to tighten wrinkles and wrinkles that are initially formed on the label when the label is applied to curved surfaces, and allows you to smooth wrinkles and wrinkles with minimal distortion of the graphics on the label. Films having uneven shrinkage, that is, films in which shrinkage is large in one direction and small or moderate in the other direction, are not very suitable, since wrinkling may increase in the other direction in the other direction. Suitable films with uniform shrinkage allow the use of labels with a wide variety of forms for applying onto containers with a wide variety of shapes.

In one embodiment, the polymer film has an ultimate shrinkage (S), measured according to ASTM D1204, in at least one direction of at least 10% at 90 ° C., and in the other direction of S ± 20%. In another embodiment, the film has an ultimate shrinkage (S) in at least one direction of about 10% to 50% at 70 ° C, and in the other direction, the shrinkage is S ± 20%. In one embodiment, the ultimate shrinkage (S) is at least 10% at 90 ° C, and in the other direction, the shrinkage is S ± 10%. The temperature of the start of shrinkage of the film, in one embodiment, is approximately 60 ° C to 80 ° C.

Shrink film should have shrinkage when exposed to heat and, at the same time, have sufficient rigidity to feed it using conventional equipment and processes for applying labels, including printing, cutting and transferring labels. The required stiffness of the film depends on the size of the label, the speed of application and the equipment used for sticking labels. In one embodiment, the shrink film has rigidity in the machine direction (MD - from the English machine direction) of at least 5 mN, measured by the method of measuring bending resistance along the length and width (L&W Bending Resistance Test). In one embodiment, the shrink film has a stiffness of at least 10 mN, or at least 20 mN. The rigidity of the shrink film is important for the proper distribution of the labels on the peeling plate at high line speeds.

In one embodiment, shaped labels are applied to an article or container on an automated label line at a line speed of at least 100 units per minute, or at least 250 units per minute, or at least 500 units per minute.

In one embodiment, the shrink film has a 2 percent cross sectional modulus of elasticity in the machine direction (MD), measured by ASTM D882, from about 20,000 to 400,000 psi (from 14 MPa to 280 MPa), and from about 20,000 to 400,000 psi (14 MPa to 280 MPa) in the transverse direction (TD - from the English trans direction). In another embodiment, a two percent secant modulus of elasticity of the film is about 30,000 to 300,000 psi (21 MPa to 420 MPa) in the machine direction and about 30,000 to 300,000 (21 MPa to 420 MPa) in the transverse direction. The film may have a module in the transverse direction less than in the machine direction so that there are no problems with the machine feeding labels while maintaining a sufficiently low module in TD to ensure good adhesion and / or indentation.

The polymer film can be made by a conventional process. For example, a film can be made using the technology of "double blowing" (double bubble process), shear-drying process, or include a film obtained by extrusion with blowing.

A shrink film suitable for the manufacture of labels may be a single layer structure or a multilayer structure. The layer or layers of shrink film can be made of a polymer selected from the group consisting of polyester, polyolefin, polyvinyl chloride, polystyrene, lactic acid polymer, copolymers and mixtures thereof.

Polyolefins include homopolymers or copolymers of olefins, which are aliphatic hydrocarbons having one or more carbon-carbon double bonds. Olefins include alkenes containing 1-alkenes, also known as alpha olefins, for example, 1-butene, and internal alkenes having carbon-carbon double bonds on non-terminal carbon atoms of the carbon chain, for example 2-butene, cyclic olefins having one or a carbon-carbon double bond, for example cyclohexane and norbornadiene, and cyclic polyenes, which are non-cyclic aliphatic hydrocarbons, having two or more carbon-carbon double bonds, for example, 1,4-butadiene and isoprene. Polyolefins comprise alkenyl homopolymers from one alkene monomer, for example a polypropylene homopolymer, alkene copolymers from at least a single alkene monomer, and one or more additional olefin monomers, where the first order alkene is the main component of a copolymer, for example, a propylene-ethylene copolymer and copolymers of propylene-ethylene-butadiene, homopolymers of cyclic olefins from a single cyclic olefin monomer, and copolymers of cyclic olefins from at least one cyclic olefin monomer on, and one or more additional olefin monomers, where the first of the listed cyclic olefin is the main component of the copolymer, as well as a mixture of any of the above olefin polymers.

In one embodiment, the shrink film is a multilayer film comprising an inner layer and at least one outer layer. The outer layer may be an outer layer, perceiving typographic printing. In one embodiment, the multilayer shrink film includes an inner layer and two outer layers, where at least one outer layer receives the print. The multilayer shrink film may be a coextruded film.

The film thickness may be in the range of 0.5-20, or 0.5-12, or 0.5-8, or 1-3 mils (1 mils = 10 ^-3 inches = 0.025 mm). The layers of the film may differ in the components of the thermoplastic copolymer, additives, orientation, thickness, or a combination of these parameters. The thickness of the inner layer may be 50-95%, or 60-95%, or 70-90% of the film thickness. The thickness of the outer layer or a combination of two outer layers can be 5-50%, or 5-40%, or 10-30% of the film thickness.

The film can also be processed on one surface or on both, the upper and lower surfaces, to improve the quality of its work in relation to the perception of printing, or adhesion to glue. The treatment may include applying a surface coating, for example, varnish, exposure to a high energy discharge to treat the surface with a corona discharge, surface treatment with a flame, or a combination of any of these treatments. In an embodiment of the invention, the film is processed on both sides, and in another embodiment, the film is treated on one surface with a corona discharge and on the other surface with a flame.

The shrink film layers may contain pigments, fillers, stabilizers, light shields, or other suitable modifying agents, if necessary. The film may also contain anti-blocking agents, slip improvers and anti-static agents. Suitable anti-blocking agents include inorganic particles, for example, clay, talc, calcium carbonate and glass. Glidants suitable for use in the present invention include polysiloxanes, waxes, fatty amides, fatty acids, metal soap, and particles, for example, silica, synthetic amorphous silica and polytetrafluoroethylene powder. Antistatic agents suitable for use in the present invention include alkali metal sulfonates, polyester modified polydiorganosiloxanes, polyalkylphenylsiloxanes and tertiary amines.

In one embodiment, the shrink film has microperforation that allows air bubbles to escape from the interface between the label and the product to which it is attached. In another embodiment, the shrink film has a permeability allowing fluid to escape from the adhesive or from the surface of the product. In one embodiment, drainage holes or slots are made in the shrink film.

Adhesives

A description of suitable pressure sensitive adhesives (contact adhesives) can be found in the Encyclopedia of Polymer Science and Engineering, vol. 13, Wiley-lnterscience Publishers, N.Y., 1988). Further descriptions of suitable contact adhesives can be found in "Science and Technology of Polymers" (Polymer Science and Technology, vol. 1, Interscience Publishers, N.Y., 1964). Commonly used contact adhesives include acrylic, rubber, and silicone based adhesives. Solvent may be used in the contact adhesive, or it may be a water adhesive. Hot melt adhesives may also be used. In one embodiment, the contact adhesive comprises an acrylic emulsion adhesive.

The adhesive and the side of the film on which this adhesive is applied have sufficient compatibility to ensure good adhesion. In one embodiment, the adhesive is selected so that the labels can be easily removed from the container of polyethylene terephthalate (PET) within 24 hours after application. Also, adhesive components must not migrate into the film.

In one embodiment, the adhesive may be formed based on an acrylic polymer. It is contemplated that any acrylic-based polymer capable of forming an adhesive layer with sufficient adherence to the substrate can be used in the present invention. In some embodiments, acrylic polymers for contact adhesive layers include compounds obtained by polymerizing at least one alkyl acrylate monomer containing from about 4 to 12 carbon atoms in the alkyl groups and comprising about 35-95 wt.% Polymer or copolymer, as this is described in US Pat. No. 5,264,532. Alternatively, an acrylic-based contact adhesive may be formed from the same type of polymers.

The glass transition temperature of a layer of contact adhesive containing acrylic polymers can be changed by controlling the amount of polar or "solid monomers" in the copolymer, as shown in US Pat. No. 5,264,532, incorporated herein by reference. The higher the percentage by weight of solid monomers in the acrylic copolymer, the higher the glass transition temperature. Solid monomers contemplated for use in the present invention include vinyl esters, carboxylic acids, and methacrylates, the weight concentration of which may be from about zero to 35% by weight of the polymer.

The contact adhesive may have an acrylic base, for example, as described in US Pat. (hot melt adhesive based on rubber). The adhesive may also be a mixture of monomers with catalysts and other ingredients, radiation curable, for example, as described in US 5232958 (UV curable acrylic adhesive) and US 5232958 (cured by electron beam). The disclosures of these patents relating to acrylic adhesives are hereby incorporated by reference.

Contact adhesives available on the market can be used in the invention. An example of such adhesives is contact hot melt adhesives supplied by N.V. Fuller Company from St. Paul, Minnesota, for example HM-1597, HL-2207-X, H1-2115-X, HL-2193-X. Other commercially available contact adhesives that may be used in the invention include adhesives supplied by Century Adhesives Corporation, Columbus, Ohio. Another suitable acrylic contact adhesive contains a mixture of emulsion polymer particles with dispersed tackifier particles, described in general terms in Example 2 of US Pat. No. 6,306,982. The polymer is prepared by emulsion polymerization of 2-ethylhexyl acrylate, vinyl acetate, dioctyl maleate and methacrylic comonomers as described US Pat. No. 5,164,444, with a resulting latex particle size of about 0.2 μm in a weight average diameter and a gel content of about 60%.

An example of a hot melt adhesive available on the market is H2187-01, manufactured by Ato Findley, Inc. from Wauwatuz, Wisconsin. In addition, the rubber-based block copolymer contact adhesives described in US Pat.

In another embodiment, the contact adhesive comprises rubber-based elastomeric materials, including suitable linear, branched and radial block copolymers represented by diblock structures A - B, triblock structures A - B - A, radial or bonded structures (A --In) _n, and combinations thereof, in which a represents a rigid thermoplastic phase or block which at room temperature has the properties not rubber but rather a glass or crystal, but becomes liquid at higher evap e, and B represents a soft block having the properties of rubber or elastomer at the operating or ambient temperature. These thermoplastic elastomers may include from about 75 wt.% To 95 wt.% Rubber segments and from about 5 wt.% To 25 wt.% Non-rubber segments.

Non-rubber segments or solid blocks contain polymers of mono- and polycyclic aromatic hydrocarbons, and in particular, vinyl-substituted aromatic hydrocarbons, which may be inherently monocyclic or bicyclic. Rubber materials such as polyisoprene, polybutadiene and a copolymer of butadiene and styrene can be used as a rubber block or segment. Particularly suitable for use are rubber segments comprising polydiene rubbers and rubbers based on saturated olefins from ethylene-butadiene or ethylene-propylene copolymers. These latter rubbers can be prepared from the corresponding unsaturated polyalkylene compounds, for example polyutadiene and polyisoprene, by their hydrogenation.

Among block copolymers of vinyl aromatic hydrocarbons and dienes with conjugated double bonds, any ones having elastomeric properties can be used. Block copolymers can be diblock, triblock, multiblock, star-shaped block copolymers, multiblock or graft block copolymers. In the present description, the terms diblock, triblock, multiblock, multiblock, graft or graft block with respect to the structural features of block copolymers should be understood in accordance with their usual meaning defined in the literature, for example, in the Scientific and Technical Encyclopedia of Polymers (Encyclopedia of Polymer Science and Engineering, vol. 2, (1985), John Wiley & Sons, Inc., NY, pp. 325-326) and in Block Copolymers. Theoretical Foundations of Technology (J.E. McGrath in Block Copolymers, Science Technology, Dale J. Meier, Ed. Harwood Academic Publishers, 1979, pp. 1-5).

Such block copolymers can have various ratios of dienes with conjugated double bonds and vinyl aromatic hydrocarbons, including those containing up to about 40 wt.% Vinyl aromatic hydrocarbons. Accordingly, multiblock copolymers having a linear, or radially symmetric, or asymmetric structure, which is represented by the formula A - B, A - B - A, A - B - A - B, B - A, can be used. --B, (AB) _{0,1,2 ...} VA, etc., where A represents a polymer block of a vinyl aromatic hydrocarbon or a truncated copolymer block of an aromatic hydrocarbon of vinyl and diene with conjugated double bonds, and B represents an elastic polymer block of dienes with conjugated double bonds.

Block copolymers can be obtained by any of the well-known methods of block polymerization or copolymerization, including sequential addition of monomers, stepwise addition of monomers, or coupling methods described, for example, in patents US 3251905; 3,390,207; 3598887 and 4219627. As is well known, truncated blocks of copolymers can be introduced into multiblock copolymers by copolymerization of a mixture of dienes with conjugated double bonds and monomers of vinyl aromatic hydrocarbons, using differences in the reaction rate of their copolymerization. The preparation of multiblock copolymers containing truncated copolymer blocks is described in US Pat. Nos. 3,251,905; 3639521 and 4208356, the disclosures of which are incorporated herein by reference.

Double-coupled dienes that can be used to make polymers and copolymers contain from 4 to about 10 carbon atoms or from 4 to 6 carbon atoms. Examples include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, chloroprene, 1,3-pentadiene, 1,3-hexadiene and etc. Mixtures of these dienes with conjugated double bonds may also be used.

Examples of vinyl aromatic hydrocarbons that can be used to prepare copolymers include styrene and various substituted styrenes, for example, o-methyl styrene, p-methyl styrene, paratret-butyl styrene, 1,3-dimethyl styrene, alpha-methyl styrene, beta-methyl styrene, p -isopropyl styrene, 2,3-dimethyl styrene, o-chlorostyrene, p-chlorostyrene, o-bromostyrene, 2-chloro-4-methylstyrene, etc.

Many of the copolymers of conjugated dienes and vinyl aromatic compounds listed above are commercially available. The number average molecular weight of the block copolymers prior to hydrogenation is from about 20,000 to about 500,000, or from about 40,000 to about 300,000.

The number average molecular weights of the individual blocks within the copolymers can vary within certain limits. In most cases, the vinyl aromatic block will have a number average molecular weight of about 2000 to 125000, or about 4000 to 60,000. The diene blocks with conjugated double bonds, either before or after hydrogenation, will have number average molecular weights of about 10,000 to 450,000. or from about 35,000 to 150,000.

In addition, before hydrogenation, the vinyl content of the diene moiety with conjugated double bonds is usually from about 10% to 80%, or from about 25% to 65%, or even from 35% to 55%, when it is required that the modified block copolymer possessed elasticity of rubber. The vinyl content in the block copolymer can be measured by means of nuclear magnetic resonance.

Specific examples of diblock copolymers include styrene-butadiene (SB), styrene-isoprene (SI), and its hydrogenated derivatives. Examples of triblock polymers include styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), alpha-methylstyrene-butadiene-alpha-methylstyrene and alpha-methylstyrene-isoprene-alpha-methylstyrene. The copolymers suitable for use in the present invention include those sold by Kraton Polymers LLC under the trademark KRATON.

When hydrogenating SBS copolymers containing a rubber segment from a mixture of 1,4 and 1,2 isomers, a styrene-ethylene-butylene styrene block copolymer (SEBS) is obtained. Similarly, the styrene-ethylene propylene-styrene block copolymer (SEPS) can be obtained by hydrogenation of an SIS polymer.

Selective hydrogenation of block copolymers can be carried out by various known methods, including hydrogenation in the presence of catalysts such as a skeletal nickel hydrogenation catalyst, noble metals such as platinum, palladium, etc., and soluble transition metal catalysts. In suitable hydrogenation processes that can be used in the invention, the diene-containing polymer or copolymer is dissolved in an inert hydrocarbon solvent, for example cyclohexane, and is hydrogenated by reaction with hydrogen in the presence of a soluble hydrogenation catalyst. Such procedures are described in US patents 3113986 and 4226952, the disclosure of which is incorporated into this description by reference. Such hydrogenation of block copolymers is carried out so as to obtain selectively hydrogenated copolymers having a residual unsaturated content in the polydiene block of about 0.5% to 20% of the initial unsaturated content before hydrogenation.

In one embodiment, the diene with conjugated double bonds forms from the block copolymer a portion saturated at least 90%, and more often at least 95%, while a portion of the aromatic vinyl is not substantially hydrogenated. Particularly suitable hydrogenated block copolymers are hydrogenated styrene-isoprene-styrene block copolymer products, for example, styrene- (ethylene / propylene) styrene block polymer. When the polystyrene-polybutadiene-polystyrene block copolymer is hydrogenated, it is desirable that the polymer ratio between 1,2-polybutadiene and 1,4-polybutadiene is from about 30:70 to 70:30. When the hydrogenation of such a block copolymer occurs, the resulting product resembles a regular block of a copolymer of ethylene and 1-butene (EB). As noted above, when a diene with conjugated double bonds is used as isoprene, the resulting hydrogenation product resembles a regular block of a copolymer of ethylene and propylene (EP).

A number of selectively hydrogenated block copolymers are manufactured by Kraton Polymers under the common trade name Kraton G. An example is the Kraton G1652, which is a hydrogenated SBS triblock containing about 30 wt.% End blocks of styrene, and the middle block, which is a copolymer of ethylene and 1-butene ( EB). There is a lower molecular weight version of G1652 called the Kraton G1650. Another block SEBS copolymer is Kraton G1651, containing about 33 wt.% Styrene. Kraton G1657 is a diblock SEBS copolymer containing about 13 wt.% Styrene. This styrene content is lower than the styrene content in Kraton G1650 and Kraton G1652.

In another embodiment, the selectively hydrogenated block copolymer is represented by the formula:

In _n (AB) _o A _p ,

where n = 0 or 1, o is from 1 to 100, p is 0 or 1; each B before hydrogenation is a predominantly polymerized hydrocarbon diene block with conjugated double bonds, in which the number average molecular weight is from about 20,000 to 450,000; each A is a predominantly polymerized vinyl aromatic hydrocarbon block in which the number average molecular weight is from about 2000 to 115000; blocks A contain from about 5 wt.% to 95 wt.% copolymer; and block B unsaturation is less than about 10% of the initial saturation. In other embodiments, implementation, the unsaturation of the block decreases during hydrogenation to less than 5% of its original value, and the average unsaturation of the hydrogenated block copolymer is reduced to less than 20% of its original value.

Block copolymers can also include functionalized polymers, for example, those obtained by reacting an alpha, beta olefinically unsaturated monobasic or dibasic carboxylic acid reagent with selectively hydrogenated block copolymers of vinyl aromatic hydrocarbons and dienes with conjugated double bonds, as described previously. The reaction of a carboxylic acid reagent with a graft block copolymer can be carried out in solutions or in a melt in the presence of an initiating free radical.

The preparation of various selectively hydrogenated block copolymers of dienes with conjugated double bonds and vinyl aromatic hydrocarbons grafted upon copolymerization with a carboxylic acid reagent is described in a number of patents, including US 4,578,429; 4657970 and 4795782, and the disclosures of these patents relating to grafted selectively hydrogenated block copolymers of dienes with conjugated double bonds and vinyl aromatic compounds, as well as the preparation of such compounds, is incorporated herein by reference. US Pat. No. 4,795,782 describes and illustrates examples of the preparation of grafted block copolymers in solution and in melt. US 4,578,429 contains an example of grafting a Kraton G1652 polymer (SEBS) with maleic anhydride with 2,5-dimethyl-2,5-di (t-butylperoxy) hexane by melt reaction in a twin screw extruder.

Examples of commercially available maleated selectively hydrogenated styrene and butadiene copolymers include Kraton FG1901X, FG1921X, and FG1924X, often referred to as maleated selectively hydrogenated SEBS copolymers. Compound FG 1901X contains about 1.7 wt.% Functionally oriented substances, for example, succinic anhydride, and about 28 wt.% Styrene. FG1921X contains about 1 wt.% Functionally oriented substances, for example, succinic anhydride, and 29 wt.% Styrene. FG1924X contains about 13% styrene and about 1% functionally oriented substance, for example, succinic anhydride.

Suitable copolymers are also available from Nippon Zeon Co., 2-1 Marunochi, Chiyoda-ku, Tokyo, Japan. For example, Nippon Zeon launches Quintac 3530, which appears to be a linear block styrene-isoprene-styrene copolymer.

Unsaturated elastomeric polymers and other polymers and copolymers that are not tacky in nature can be made tacky by incorporating a tackifier. Tackifiers, typically hydrocarbon resins, wood resins, rosins, rosin derivatives, and the like, in concentrations of from about 40 wt.% To 90 wt.% Of the total weight of the adhesive composition, or from about 45 wt.% To 85 wt.%, Impart contact adhesion properties to the adhesive composition of the elastomeric polymer. Compositions in which the content of the tackifier enhancer additive is less than 40 wt.%, Usually do not have the property of "instant adhesion" or the initial tack, allowing them to be used as contact adhesives, and therefore are not initially sticky. On the other hand, compositions in which the content of the tackifier is too high usually have too little adhesion to be used in most applications in accordance with the present invention.

It is contemplated that in an embodiment of the present invention, any tackifier known to those skilled in the art, compatible with elastomeric polymer compositions, may be used. One such suitable tackifier is Wingtak 10, a room temperature synthetic polyterpene resin, manufactured by Goodyear Tire and Rubber Company of Akron, Ohio. Goodyear also produces a synthetic resin, the Wingtak 95 tackifier, which contains mainly a polymer derived from piperylene and isoprene. Other suitable tackifiers include Escorez 1310 and Escorez 2596 aliphatic hydrocarbon resins, which are C5-C9 (aromatic modified aliphatic) resins manufactured by Exxon from Irving, Texas. Of course, it will be understood by those skilled in the art that a variety of tackifier additives can be used in the present invention.

In addition to tackifiers, other additives can be added to contact adhesives to give them the necessary properties. For example, plasticizers can be added that are known to lower the glass transition temperature of an adhesive composition containing elastomeric polymers. An example of a plasticizer that can be used in the invention is Shellflex 371, a naphthenic oil manufactured by Shell Lubricants from Texas. Antioxidants may also be added to adhesive compositions. Suitable antioxidants include Irgafos 168 and Irganox 565, available from Ciba-Geigy, Hawthorne, NY. Abrasive materials, such as waxes and surfactants, may also be incorporated into the adhesive.

The application of contact adhesive can be made from a solution, emulsion or suspension, or in the form of a melt. The adhesive can be applied to the inner surface of the shrink film in any known manner. For example, the adhesive composition can be applied by knurling, filling, spraying, dipping, engraved cylinder or flexography. The adhesive can be applied to the shrink film in a continuous layer, an intermittent layer, or on a stencil. The adhesive applied on the screen covers essentially the entire inner surface of the film. In the present description, the term "essentially closes" implies that the stencil completely covers the surface of the film, and does not include cases where the adhesive is applied only to the strip along the front and rear edges of the film, or by a "point seam" on the film.

In one embodiment, a tackifier is applied to areas of the adhesive layer to allow labeling to adhere to complex shapes. In one embodiment, a non-adhesive material, such as dots or microdroplets of printing ink, is applied to at least a portion of the adhesive surface to allow the adhesive layer to slide over the surface of the product when applying the label and / or to allow air to escape between the label and the product .

A single adhesive layer or several layers may be used. Depending on the shrink film used, and the product or container on which the label is applied, it may be desirable to make the first adhesive layer adjacent to the shrink film, and apply a second adhesive layer having a composition different from the first layer to provide sufficient adhesion, peel strength and shear strength.

In one embodiment, the contact adhesive has sufficient shear strength or adhesion to prevent excessive shrinkage of the label attached to the product when exposed to heat after applying the film to the label, has sufficient peel strength to prevent the film from peeling off from the product, and has sufficient tack or grip strength to provide the necessary strength to attach the label to the product when it is applied. In one embodiment, the adhesive layer moves with the label as the film shrinks when exposed to heat. In another embodiment, the adhesive holds the label so that when the film shrinks, the label does not move.

The heat-shrinkable film may include other layers, in addition to a single-layer or multilayer heat-shrinkable polymer film. In one embodiment, metallization in the form of a thin metal film is applied to the surface of the polymer film. The heat shrinkable film may also include a print layer on a polymer film. The print layer can be placed between the heat-shrinkable layer and the adhesive layer, or the print layer can be on the outside of the shrink layer. In one embodiment, the printing of a pattern, image or text is used so that the print side of the film is in contact with the container on which the film is applied. In this case, the film is transparent.

Labels proposed in the present invention may also include a layer of ink-sensitive composition to improve the printing properties of the polymer shrink layer, or the metal layer, if any, and the quality of the resulting print layer. Several such compositions are known which typically include a binder material and a pigment, for example, silica or talc, distributed in the binder. Thanks to the presence of pigment, the drying time of some paints is reduced. Such paint-sensitive compositions are described in US Pat. No. 6,153,288 (Sheeh et al.), And the disclosure of this patent is incorporated herein by reference.

The printing layer may be a printing ink layer or a graphics layer, and the printing layer may be a monochrome or multi-color printing layer, depending on the print content and / or the intended label design. This includes various imprinted data, for example, lot number, bar codes, trademarks, etc. The thickness of the print layer is usually about 0.5-10 microns, in one embodiment, about 1 to 5 microns, in another embodiment, about 3 microns. Ink used in the print layer includes water-based inks, solvent inks, or photo-curable inks on the market. Examples of such inks include Sun Sheen (a product of Sun Chemical, an alcohol-soluble polyamide paint), Suntex MP (a Sun Chemical product, a solvent ink intended for surface printing of acrylic coated substrates, polyvinylidene chloride coated substrates and polyolefin films), X-Cel (a product of Water Ink Technologies, which is an ink for a water-based film, for printing on film substrates), UvilithAR-109 Rubine Red (a product of Daw Ink, which is a UV ink) and CLA91598F ( Recreatives Products company Sun Chemical, representing a multiply black paint with a solvent).

In one embodiment, the print layer includes polyester / vinyl paint, polyamide paint, acrylic paint and / or polyester paint. The printing layer can be formed in the usual way, for example, by applying an engraved cylinder, flexography or UV flexography, or the like, wherein the ink includes a resin, as described above, a suitable pigment or dye, and one or more suitable volatile solvent, on one or more necessary sections of the film. After applying the ink composition, the volatile components of the solvent included in the ink evaporate, leaving only non-volatile components that form the print layer.

The adhesion of the paint to the surface of the polymer shrink film or metal layer (if any) can be improved, if necessary, by methods well known in the art. For example, as described above, before applying paint to a metal layer or a layer of a polymer film, a primer or other composition can be applied that enhances the adhesion of the paint. Alternatively, the surface of the polymer film may be corona treated or flame treated to improve the adhesion of the ink to the polymer film layer.

Suitable primers for paint can be transparent or opaque, in addition, primers can be solvent based or aqueous. In one embodiment, the primers are cured by radiation (e.g., ultraviolet light). The primer for paint may contain varnish or thinner. The varnish may consist of one or more compounds from the group consisting of polyolefins, polyamides, polyesters, copolymers of polyesters, polyurethanes, polysulfones, polyvinylidene chloride, copolymers of styrene-maleic anhydride, copolymers of styrene-acrylonitrile, ionomers based on sodium or zinc acrylic acid or ethylene acid polymethylmethacrylates, acrylic polymers and copolymers, and mixtures of two or more of these compounds. Examples of diluents that can be used include alcohols, for example, ethyl, isopropyl and butyl; esters, for example ethyl acetate, propyl acetate and butyl acetate; aromatic hydrocarbons, for example, toluene and xylene; ketones, for example acetone and methyl ethyl ketone; aliphatic hydrocarbons, for example heptane; and mixtures thereof. The ratio of varnish and diluent depends on the viscosity needed to apply the primer for the paint, and the principles for choosing this viscosity are known to those skilled in the art. The primer layer for the paint may have a thickness of from about 1 to 4 microns, or from about 1.5 to 3 microns.

A transparent protective or covering polymer layer may be used in the label of the invention. The protective layer can provide the label with the desired properties before and after the label is attached to a substrate, such as a container. The presence of a transparent protective or cover layer over the print layer may, in some embodiments, provide additional properties, for example, antistatic properties, rigidity, and / or weather resistance. The protective layer can protect the print layer from, for example, weather, solar radiation, abrasion, moisture, water, etc. A transparent protective layer can improve the properties of the underlying print layer, adding gloss and saturation to the image. The protective transparent layer can also be made resistant to abrasion, to radiation (for example, ultraviolet), chemically resistant, heat-resistant, thereby protecting the label and, in particular, the printing layer, from degradation from these effects. The protective layer may also contain anti-static additives, or anti-adhesive additives that simplify the handling of labels when applied to the container at high speed. A protective layer may be applied to the printing layer using techniques known to those skilled in the art. A polymer film can be applied from a solution, like a preformed film (laminated to the printing layer), etc.

A transparent protective or covering layer, if present, may be a single layer or multilayer structure. The thickness of the protective layer is usually from about 12.5 to 125 microns, and in one embodiment, from about 25 to 75 microns. Examples of cover layers are given in US Pat. No. 6,106,982, incorporated herein by reference.

The protective layer may contain polyolefins, thermoplastic polymers of ethylene and propylene, polyesters, polyurethanes, polyacryls, polymethacryls, epoxies, vinyl acetate homopolymers, copolymers or ternary polymers, ionomers and mixtures thereof.

The transparent protective layer may contain ultraviolet light absorbers and / or other light stabilizers. UV absorbers that can be used include sterically hindered amines manufactured by Ciba Specialty Chemical under the brand name Tinuvin. Light stabilizers that can be used include sterically hindered amine light stabilizers manufactured by Ciba Specialty Chemical under the brand name Tinuvin 111, Tinuvin 123 (bis- (1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacinate; Tinuvin 622 (dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethyl-4-piperidinethanol); Tinuvin 770 (bis- (2,2,6,6-tetramethyl-4-piperidinyl) and Tinuvin 783. Additional light stabilizers include sterically hindered amine light stabilizers manufactured by Ciba Specialty Chemical under the brand name Che massorb, in particular Chemassorb 119 and Chemassorb 944. The concentration of the UV absorber and / or light stabilizer is up to about 2.5 wt.% and in one embodiment, from about 0.05 to 1 wt.%.

The clear protective layer may contain an antioxidant. Any antioxidant suitable for the manufacture of thermoplastic films may be used. These include sterically hindered phenols and organophosphites. As an example, we can take products manufactured by Ciba Specialty Chemical under the trademarks Irganox 1010, Irganox 1076 or Irgafos 168. The concentration of antioxidant in the composition of the thermoplastic film can be up to about 2.5 wt.% And in one embodiment, from about 0.05 wt.% up to 1 wt.%.

A detachable pad may be attached to the adhesive layer to protect the adhesive layer during transportation, storage and any manipulations prior to applying the label to the substrate. The release liner may have an embossed surface and / or may have non-adhesive material, for example, microdrops or paint spots applied to the surface of the gasket.

Process

The process of labeling products or containers involves unconventional operations and equipment. The process begins in the usual dispensing equipment, in which the label is separated from the detachable gasket by means of a peeling plate or tip, after which the label is exposed with a bare adhesive layer to the container or product for application. As shown in FIGS. 13-16, the label 62 having a central portion 61 and a peripheral portion 63 surrounding the central portion, the outer boundary of which is formed by the edges of the label, is brought into contact with the container 60, first by applying pressure to the label in the central portion. Due to the fact that the starting point (s) 64 of adhesion is located rather in the central part of the label than on the front edge or the peripheral part of the label, a more even distribution of all appearing folds and wrinkles formed between the front and rear edges of the applied label is ensured. This, in turn, simplifies the removal of wrinkles and wrinkles through thermal exposure.

In the case of products having both surfaces with complex curvature and relatively flat regions, the label is first applied to the container not on the surface with complex curvature, but closer to or within the relatively flat region of the surface of the container.

In one embodiment, the label is preheated to soften the shrink film and / or to activate the adhesive layer.

The pressure on the transferred label is applied by a series of brushes, rollers, squeeze rollers, rubber scrapers, pneumatic rollers, or a movable cross member in the center outward, as shown by arrows 65, to ensure a snug fit between the label and the container or product. This process is called label spinning. The smoothing movement from the center to the edge displaces any air that has fallen under the label to the outer edges, as shown by arrows 66, and creates smaller and more evenly distributed folds along the edges of the label. Since the label covers the surface of the product with complex curvature, excess label material accumulates in the form of folds, wrinkles, channels and bubbles and other defects in application, mainly in the peripheral part of the label. At least a portion of the label is exposed to heat to ensure that the label adheres completely and smoothly to the container, as shown in FIG. 16.

In one embodiment, pressure is applied to the label by means of a system with a movable cross member equipped with a foam roll or a foam coated cross member. The foam roll, or cross member, acts with downward pressure in the longitudinal direction to the central part of the label, and then moves to the outer edges of the label, directing the air and wrinkles remaining under the label, wrinkles and / or other defects to the outer edges of the label. This embodiment is illustrated in FIGS. 17 and 18, where a container 70 with a label 71 attached thereto is shown placed on the lower foam block 72a of the movable cross member. The upper foam block 72b applies downward pressure to the label 71 on the container 70 to expel air from under the center of the label at the periphery of the label as the label and container squeeze between the foam blocks of the movable cross member.

After the label is attached and the initial smoothing is completed, folds of excess material and defects are eliminated by heating at least part of the label to shrink wrinkles and / or wrinkles. The label can be heated by passing it through a hot tunnel, by blowing it with a stream of air, in a tunnel with steam, by direct contact with heated plates or forms. In one embodiment, the label is heated to a temperature of at least 40 ° C. In one embodiment, the label is heated to at least 60 ° C, or at least 70 ° C, or at least 80 ° C.

The label can then be smoothed to remove any wrinkles or wrinkles on the label. The label is again applied pressure from the center to the periphery of the label. The second smoothing can be performed by a series of rollers, squeeze rollers, rubber scrapers, brushes, pneumatic rollers, or a movable cross member. Then, a new smoothing can be carried out with exposure to the heating label, or after exposure to heating.

When applying the label to the product or container, the label can first be pre-glued to the product by applying pressure in the contact area of the label, after which pressure is applied across the label towards the first edge of the label. The contact area may be in the center of the label, or near the second edge, located on the opposite side from the first edge. For example, the initial contact may be in the center of the label, after which the applied pressure is directed outward to the edges or periphery of the label. Alternatively, the initial contact may be near one edge of the label, and then applied pressure may be directed across the label to the opposite edge of the label. When applying a label to a product or container, it is advisable to shift the excess material, i.e. wrinkles or wrinkles to at least one edge of the label. The excess material is usually shifted in the direction of complex curvature, where under the influence of the heating label, it shrinks and adheres to the surface of complex curvature, and any wrinkles or wrinkles that are formed are removed. Exposing the label to heat and pressure can be simultaneous.

In one embodiment of the invention, a method of applying a label to an article includes preparing an article having a surface with at least one complex curvature, preparing a label including a heat-shrinkable film having an inner surface and an outer surface, and a layer of contact adhesive on the inner surface of the heat-shrinkable film, the label has a first edge and a contact area; bringing the contact adhesive layer into contact with the product and simultaneously applying heat and pressure to the label in the direction from the contact area to the first edge so that the first edge of the label adheres to the product and the label shrinks so that it takes the form of complex curvature products, while the action of heating and pressure is carried out by at least one hot air squeegee assembly, including a source of heated air, a flow control mechanism and one or more doctor blades s with hot air. Alternatively, the contact area may be near the second edge of the label on the opposite side from the first edge.

FIGS. 19 and 20 show an embodiment of the invention in which a hot air squeegee assembly is used to label a product or container. The label may be applied to one or both sides of the container. For ease of explanation, a label is applied to one surface of the container in FIGS. 19 and 20. The hot air squeegee assembly includes a hot air source, a flow control mechanism, and one or more hot air squeegees. As shown in FIG. 19, two squeegee slots 84a, 84b direct hot air at a high speed to the center region 83c of label 82. Label 82 is first applied to center region 83c of container 81 through a standard label distribution process using a removable backing layer (not shown) while the leading edge (first edge 83a) and the trailing edge (second edge 83b) are not adhered. A container with a conveyor previously attached to it with a label is conveyed to the hot air squeegee assembly. Depending on the size and configuration of the container, additional hot air squeegees and / or hot air squeegee assemblies can be used to expose the label to heat and pressure. As shown in FIG. 20, the hot air squeegees 84a, 84b are turned outward, directing hot air from the center of the label 83c to the first edge 83a and the second edge 83b of the label 82. When hot air presses the label 82, the air between the label and the container 81 is squeezed out to the edges 83a, 83b of the label, smoothing the label and removing or reducing air bubbles under the label. Hot air directed to the label 82 softens the label and seats it. The simultaneous exposure to the label by heating and pressure from the squeegee slots 84a, 84b with hot air causes the label to take the form of the surface of the container 81, including surfaces of complex curvature of the container. For further shrinkage of the label, an additional heating step may be used. The advantage of this method is that there is no direct contact with the label, and surface defects are not printed on the label. The advantage is also the ability to achieve high speeds of the process, due to the excellent heat transfer to the film and continuous reuse of heating in the squeegee assembly of hot air. This method can be used to apply labels to various containers and products without changing tooling.

On Fig-25 presents an embodiment in which a group of squeegee slots with air and / or nodes of the air squeegee is used to apply the label to the container or product in several consecutive steps. The label may be applied to one or both sides of the container. The label is shown applied to only one surface of the container depicted in Fig.21-25. The hot air squeegee assembly includes a hot air source, a flow control mechanism, and at least one hot air squeegee. In the initial stage shown in FIG. 21, a hot air squeegee 94 directs hot air at high speed to the center region 93c of the label 92. The label 92 is first applied to the center region 93c of the container 91 by a standard label distribution process (not shown) using a removable label a protective layer, while the front edge (first edge 93a) and the rear edge (second edge 93b) are not glued. The container with the label pre-glued onto it is conveyed by the conveyor to the doctor blade assembly. As shown in FIG. 22, when transporting the container 91 along the conveyor past the doctor blade 94, hot air is pumped onto the label 92 towards the first edge 93a of the label, heating the label and forcing it to fit snugly against the surface of the container 91, while the second edge 93b not adhering and / or not sticking. Then the container is rotated 180 °, as shown in Fig.23. On Fig shows how the container 91 with the label 92 glued to it is delivered to the second hot air gap 95, from which hot air is pumped into the label 92 in the direction from the center 93c to the second edge 93b of the label, heating the label and making it fit snugly to the surface of the container 91, as shown in FIG. Depending on the configuration and size of the container, additional hot air squeegees and / or hot air squeegee assemblies can be used for exposure to heat and pressure. For further shrinkage of the label, heating can then be used.

A labeled product in accordance with the present invention can be used for various applications, including personal care products, household chemicals, food and drinks, toys, electronics, pharmaceuticals, health care products, industrial and household appliances, as well as other applications.

Examples

The following examples are intended only to illustrate the methods and embodiments proposed in the invention and should not be construed as limiting the claims.

Example 1

The self-adhesive shrink label is formed from a 3-thousand-inch-thick multi-layer shrink film made from Sealed Air CorrTuff. The film is coated with Avery Dennison S692N Acrylic Emulsion Adhesive. The adhesive has been applied to the Glassline BG-40 peel-off paper with silicone coating. The label has enlarged dimensions, approximately 5 × 3.5 inches (12.7 × 8.9 cm), which is 20% larger than the industry standard recommended label size for the bottle on which the label is applied.

A 15-ounce (425 g) Johnson & Johnson Baby Lotion bottle with a surface of complex curvature is filled with water, closed and processed on a Label-Aire 9000 type labeling machine with a capacity of 100 bottles per minute (b / min). The labeling machine has a double screw feed with an agreed speed of the upper and lower conveyors, with labeling heads like Label Aire 2115-CD driven by a high-torque stepper motor. The labels are pressed by a smoothing device with a movable cross member, providing the action of forces directed from the center to the outside, to divert air that has fallen under the label and the corresponding defects such as wrinkles / wrinkles to the edge of the label. The oversized label, when applied to the bottle, first has unacceptable defects in the form of small folds and wrinkles around the perimeter of the label. Next, the bottle with the label is processed in a conveyor smoothing system such as Leister with a hot air blow with a capacity of 100 bpm. Hot air at a temperature of 260 ° C, pumped at high speed, heats the bottle and label to 50 ° C, causing shrinkage and removal of excess label material in the form of folds and wrinkles on the surface of the bottle. The label is smoothed out with a movable cross member to ensure a good fit. The wrinkles shrink and are easily smoothed out after exposure to heat.

The finished bottle with a label, with an increased label area and an expanded graphic content, is well smoothed without wrinkles, waves and wrinkles and other defects found in ordinary oversized self-adhesive labels. Creases do not form again with aging labels. Table 1 below shows the properties of the components of the label.

Example 2

In accordance with the process described in Example 1, a self-adhesive shrink label formed of a 2 thousandth inch (0.05 mm) thick polypropylene shrink film, labeled CZPA 200, manufactured by Innovia, is applied to a bottle having a surface with complex curvature. After the initial smoothing, medium-sized folds are formed. Hot air, pumped at high speed, heats the bottle and label to 100 ° C. The folds sit down and are easily smoothed flush with the bottle after exposure to heat. After exposure, folds do not reappear.

Example 3

In accordance with the process described in Example 1, a self-adhesive shrink label formed from a single-layer shrink film of a lactic acid polymer, called EARTHFIRST PLA, Plastic Suppliers, is applied to a bottle having a surface with complex curvature. After the initial smoothing, medium-sized folds are formed. Hot air, pumped at high speed, heats the bottle and label to 70 ° C. The folds shrink and are easily smoothed out after exposure to heat, becoming smooth. After exposure, folds do not reappear.

Comparative Example 4

In accordance with the process described in Example 1, a self-adhesive shrink film formed from a machine-oriented polypropylene single-layer shrink film of Avery Dennison company, a thickness of 2 thousandths of an inch (0.05 mm), hot rolled, is applied to a bottle having a surface with complex curvature. Hot air, pumped at high speed, heats the bottle and label to 70 ° C. The folds formed in the upper and lower parts of the label shrink when exposed to heat and are easily smoothed out, while the folds formed at the front and rear edges remain. Removed creases do not reappear when the label ages.

Comparative Example 5

In accordance with the process described in Example 1, a self-adhesive shrink label formed from a transverse oriented polyvinyl chloride single-layer film with a thickness of 1.9 thousandths of an inch (0.048 mm), under the name Penta Label, from Kloeckner, is applied to a bottle with a complex curvature surface. Hot air, pumped at high speed, heats the bottle and label to 60 ° C. The folds formed at the front and rear edges of the label shrink when exposed to heat and are easily smoothed out, while the folds formed on the top and bottom of the label remain. Removed creases do not reappear when the label ages.

Comparative Example 6

In accordance with the process described in Example 1, a self-adhesive shrink label formed from a laterally oriented single-layer film of glycol-modified polyethylene terephthalate (PETG), 2 thousandths of a inch (0.05 mm) thick, designated Fusion 1775E, from Mitsubishi, applied to a bottle with a surface of complex curvature. Hot air, pumped at high speed, heats the bottle and label to 50 ° C. The folds formed at the front and rear edges of the label shrink when exposed to heat and are easily smoothed out, while the folds formed on the top and bottom of the label remain. Removed creases do not reappear when the label ages.

Comparative Example 7

In accordance with the process described in Example 1, a self-adhesive shrink label formed from a machine-oriented polyvinyl chloride single-layer film with a thickness of 1.4 thousandths of an inch (0.036 mm), designated MF-L243 / 01, manufactured by Kloechner, is applied to a bottle with a complex surface curvature. Hot air, pumped at high speed, heats the bottle and label to 60 ° C. The film does not fit snugly against the container. Initial smoothing gives poor results, and many folds form in all directions. Folds and wrinkles remain after exposure to heat and a second smoothing. Significant re-warping of the film occurs.

Comparative Example 8

In accordance with the process described in Example 1, a self-adhesive shrink label formed of a 2 thousandth inch (0.05 mm) thick polypropylene film labeled BTNY, manufactured by Vifan, is applied to a bottle having a surface with complex curvature. Hot air, pumped at high speed, heats the bottle and label to 100 ° C. The formed folds do not completely shrink at high temperature and do not completely smooth out flush with the surface. During aging, the wrinkles are returned.

Comparative Example 9

In accordance with the process described in Example 1, a self-adhesive shrink label formed of a 3.4 thousandths of an inch thick (0.086 mm) multilayer film of medium density polyethylene (MDPE), designated PE 85, manufactured by Charter Films, is applied to a bottle, having a surface with complex curvature. Hot air, pumped at high speed, heats the bottle and label to 100 ° C. The formed folds do not completely shrink at high temperature and do not completely smooth out flush with the surface. During aging, the wrinkles are returned.

Claims (22)

1. A method of applying a label to a product, comprising providing the product with a surface having at least one complex curvature, and
providing a label containing
(i) heat-shrinkable film with internal and external surfaces and with machine and transverse directions;
(ii) a layer of contact adhesive on the inner surface of the film, wherein
(iii) the label contains a first edge and a contact area;
bringing into contact with the product a layer of contact adhesive in the contact zone of the label, and
the simultaneous action of heat and pressure on the label in the direction from the contact zone to the first edge to stick it to the product and subject the label to shrinkage to accept the curvature of the product, and the action of heating and pressure is performed by at least one hot air squeegee assembly containing a hot air source a flow control mechanism and at least one hot air squeegee,
characterized in that
the heat-shrinkable film is made with a maximum shrinkage S in at least one of the machine or transverse directions of at least 10% at 90 ° C, and the shrinkage in the other direction is S ± 20%. 2. The method according to claim 1, in which a label is used having a center and a second edge opposite the first edge, wherein the contact area is located near the center or in the center of the label. 3. The method according to claim 1, in which a label is used having a second edge opposite the first edge, wherein the contact area is located near the second edge of the label. 4. The method according to claim 2, in which use the site of the squeegee of hot air containing at least two squeegee slots with hot air, which rotate outward from the center of the label to the first and second edges for gluing the label to the product. 5. The method according to claim 2, in which heating and pressure is carried out on the label from the center to the first edge of the first doctor blade with hot air, and the second doctor blade is exposed to heat and pressure on the label from its center to the second edge. 6. The method according to claim 5, in which the product is rotated approximately 180 ° before exposure to heat and pressure on the label of the second doctor blade. 7. The method according to any one of claims 1 to 6, in which a label is used, provided with a detachable gasket glued to the adhesive layer, and the gasket is separated from the label before bringing the label into contact with the product. 8. The method according to any one of claims 1 to 6, in which the label is heated to at least 40 ° C. 9. The method according to any one of claims 1 to 6, in which a film is used, which is a film of polyester, polyolefin, polyvinyl chloride, polystyrene, lactic acid polymer, copolymers or mixtures thereof. 10. The method according to any one of claims 1 to 6, in which a film representing a polyolefin is used. 11. The method according to any one of claims 1 to 6, in which a film is used that is multilayer with an inner and at least one outer layer. 12. The method according to any one of claims 1 to 6, in which a film having a machine direction and a rigidity in it of at least 5 mN is used. 13. The method according to any one of claims 1 to 6, in which a label is used containing a print layer between the film and the adhesive layer, the film being transparent. 14. The method according to any one of claims 1 to 6, in which use a label, optionally containing a print layer on the outer surface of the film. 15. The method according to 14, in which use the label, optionally containing a protective layer covering the print layer. 16. The method according to any one of claims 1 to 6, in which an adhesive layer containing an emulsion adhesive composition is used. 17. The method according to any one of claims 1 to 6, in which an adhesive layer containing hot melt adhesive is used. 18. The method according to any one of claims 1 to 6, in which an adhesive layer containing a solvent based adhesive is used. 19. The method according to any one of claims 1 to 6, in which the layer of contact adhesive is continuous. 20. The method according to any one of claims 1 to 6, in which a layer of contact adhesive is performed on a stencil essentially covering the inner surface of the film. 21. The method according to any one of claims 1 to 6, in which the maximum shrinkage S in at least one direction is at least 10% at 90 ° C, and the shrinkage in the other direction is S ± 10%. 22. The method according to any one of claims 1 to 6, in which the film is additionally heated after simultaneous exposure to heat and pressure by the squeegee assembly.

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