WO2018070905A1 - Method for producing a multi-layer material by applying an extruded polymeric coating during calendering - Google Patents

Abstract

The invention relates to multi-layer polymeric materials for producing packaging and other products, and more particularly to a method for producing a multi-layer material (11) in rolls or sheets. The method comprises applying a polymeric coating onto a base film (1) having at least one polymeric supporting layer (2) and, bonded thereto, at least one non-polymeric functional or decorative layer (3). When applying the coating, an extruded molten polymeric material (9) is passed successively through at least two gaps between cooling calender rollers, wherein a coating polymeric layer (14), which is thicker than the base film, is formed in the first gap, and the base film (1) is fed into the second or subsequent gap where the bonding between the coating polymeric layer (14) and the base film (2) is formed. Moreover, in said gap, the base film (1) is made to envelop one of the calender rollers (6) so that one side of the base film (1) is in direct contact with the surface of said calender roller (6), and the other side of the base film (1) is in direct contact with the coating polymeric layer (14). The technical result is reduced deformation of the base film, in particular the decorative or functional layer, simplified technology and increased productivity thereof.

Description

 A method of obtaining a multilayer material by applying elastomer polymer coating during calendering

 The invention relates to the field of polymeric materials for the production of packaging and other products, and in particular to a method for producing a rolled or sheet multilayer material. State of the art

 Polymer-based materials that have decorative or functional layers, in particular printed layers (ink layers), metallized and barrier layers, are widely used as materials for packaging production.

 However, decoration (printing, metallization, dulling, etc.) of hard polymer films with a thickness of 150 microns or more is associated with the need to use special, expensive equipment. Printing on such thick films is not economically feasible. It is possible to apply inexpensive printing methods, for example flexoprinting. However, when it is used on films of the specified thickness, rapid wear of the equipment occurs. This raises technological difficulties in ensuring print quality.

 Therefore, in the production of materials with a thickness of more than 150 microns, it is advisable to apply various technologies for connecting a thin polymer film (10-100 microns), having a decorative or functional layer, with a thicker polymer film (150-1000 microns).

 Known technologies for joining films in which films are passed through calender gaps while heating (see, for example, RF patent RU2152339, July 10, 2000). Known methods for co-extrusion of films and their subsequent calendering (see, for example, RF patent RU2202473, 04.20.2003). Also known are technologies for the formation of laminating layers by laminating or extrusion of a material onto a substrate (see, for example, RF patent RU2329187, July 20, 2008).

 The technology of extrusion lamination is widely known, in which adhesive material is extruded between two joined films (see, for example, RF patent RU2405676, 12/10/2010).

The above technologies are not suitable for producing thick films with a decorative or functional layer, since processing occurs deformation of the layers, which affects their consumer and operational qualities. In particular, when the printing layer is deformed, there is a distortion of the inscriptions and drawings made on the packaging material.

 The technology of “in-mold labeling) has found wide application for the production of packaging with printing)) (see, for example, US patent, US7588157, September 15, 2009). According to this technology, an initial film (label) having a printing layer is melted into a finished product (for example, a container) during its formation. The disadvantage of this technology is its complexity, as well as the need to use expensive equipment. In addition, it is not suitable for roll and sheet materials.

 As the closest analogue of the considered solution to the totality of the techniques used, the method for producing a multilayer material disclosed in Japanese patent JP2600273, 10.24.1989, can be selected. According to this method, the original corrugated sheet material with a thickness of 20 to 500 μm, an HMeiouibq print layer, is passed between calendars. At the same time, a second film obtained by extrusion is fed onto the printing layer, calendering the packet of layers, heating it and then compressing it to obtain a multilayer material with a thickness of 1 to 10 mm. The initial film is made of acrylic resin, and the covering layer is made of polyvinyl chloride or acrylic resin. This technology also has the disadvantage of deformation of the printed layer.

Disclosure of invention

 The objective of the invention is to provide a simple technology for producing multilayer sheet or rolled materials based on polymers having a decorative or functional layer for the manufacture of packaging or other products.

 The technical result of the invention is to reduce the deformation of the original film, in particular a decorative or functional layer, simplifying the technology (in particular, refusing to use an adhesive layer of glue), increasing the productivity of the technology, reducing cost, expanding the ability to apply layers of various materials.

The specified technical result is achieved due to the fact that the method of producing a multilayer sheet or roll material involves applying a polymer coating to the original film having at least one supporting polymer layer and at least one non-polymer functional or a decorative layer, moreover, when coating is applied, the molten extruded polymer material is successively passed through at least two gaps of the cooling calendars, with the formation of a coating polymer layer with a thickness greater than the thickness of the original film in the first gap, and the initial film is fed into the second or subsequent gap to provide a connection covering the polymer layer and the original film, while in the specified gap provide coverage of the original film of one of the calendars with direct contact m first side of the starting film to the surface of the calender, and the second side of the original film - with the coating polymer layer.

 In addition, there are private options for implementing the method, according to which:

 - a coating polymer layer is applied from the side of the reference polymer layer of the original film,

 the coating polymer layer is applied from the side of the non-polymer decorative or functional layer of the original film,

 - the molten extruded polymer material is passed through at least three gaps of the cooling calendars, and an additional film is fed into the third or subsequent gap of these calendars to ensure its connection with the coating polymer layer,

 - use three calendars placed vertically or at an angle, with the first calendaring gap formed by the upper and middle calendars, and the second calendaring gap formed by the middle and lower calendars, and when coating is applied, they cover the initial film of the lower calender,

 - before feeding the original film into the second calender gap, provide it with a clamp to the covering polymer layer by means of a clamping shaft,

 - use the original film, in which the reference polymer layer is made of polyethylene or polypropylene, or polyethylene terephthalate,

 - use the original film, in which the non-polymer decorative or functional layer is a printing layer and / or a barrier layer, and / or a reflective layer,

 - as a coating polymer layer, a layer of polyethylene or polypropylene, or polyethylene terephthalate, or polystyrene, or polyvinyl chloride is applied,

- use an additional film made of polyethylene or polypropylene, or polyethylene terephthalate, - use the original film in which the thickness of the support layer is 10-100 μm,

 use the original film in which the thickness of the non-polymer functional or decorative layer is 1-50 microns,

 - covering polymer layer is applied with a thickness of 150-1000 microns,

 - when coating the temperature of the calendars (4,5,6) is 25 - 130 ° C,

- when coating, the molten extruded polymer material has a temperature of 200 - 300 ° C, and the coating polymer layer when fed into the second calender gap has a temperature of 150-230 ° C.

 In contrast to the known technologies, in the claimed method, the coating (lamination) of the film with a non-polymer decorative or functional layer in the calendars is carried out in such a way that it covers one of the calendars in contact with most of its surface, and a plastic coating layer formed of extruded polymer material , served on the other side of the original film, not in contact with the calender. Due to the calender cooling of the film in contact with it, the latter, upon contact with heated polymer material, does not heat up to the melting point or an unstable physical and mechanical state. Thus, this technique allows to reduce the deformation of the original film and preserve the geometry of the non-polymer functional or decorative layer.

Brief Description of the Drawings

 The invention is illustrated by drawings, where:

 - figure 1 shows examples of the configuration of the original film,

 - figure 2 shows examples of the configuration of the obtained multilayer material,

 - figure 3 shows a line for implementing the inventive method. The implementation of the invention

The initial film (1) for coating (lamination) (Fig. 1) is a rolled or sheet material and contains at least one polymer support layer (2) and at least one non-polymer functional or decorative layer connected to it (3) . As the material of the support layer, in particular, polyethylene, polypropylene, polyethylene terephthalate, etc. can be used. As a decorative non-polymer layer (3), a printed layer can be used (coat of paint). As a functional non-polymer layer (3), a barrier and metallized layer can be used.

 The initial film may have a supporting polymer layer (2) and a non-polymer layer (3) or two supporting polymer layers (2) deposited on one of its sides (see figa, 16), between which there is a non-polymer functional or decorative layer (3 )

 The starting film (1) may include either one or several support layers connected by coextrusion with the addition of barrier layers within each layer.

Variants of combining in the original film the functional and decorative layers located on separate supporting layers connected by an adhesive layer are possible. The thickness of each of the layers (2) and (3) is preferably from 1 to 50 microns.

 The initial film can be obtained by standard technology, which involves applying a decorative or functional layer to a polymer substrate (backing layer). In particular, flexo, rotogravure or offset, and other types of printing can be used. .

 The line for implementing the inventive method (FIG. 3) includes at least three rotating calendars (4,5,6) (shafts) forming two or more gaps for sequentially passing the extruded material. These calendars (4,5,6) can be located vertically one above the other or horizontally, or at an angle.

 The line design includes a flat-slot extruder (7) with a die (8) for feeding the molten extruded material (9) into the first calender gap. In the case of three calendars arranged vertically (as shown in Fig. 3), the molten extruded material (9) is fed in such a way that the first gap is formed by the upper (4) and middle (5) calendars, and the second gap is formed by the middle (5) and lower calendars (6).

 The original film (1) can be fed into the second gap of the calendars (5) and (6), or in any of the subsequent gaps (third, fourth, etc.), if any. When using tape (roll material) as the initial film (1), it is fed through an unwinding unit (10), and the resulting multilayer material (11) enters the rewinder (12). To obtain individual sheets of material, a knife for cutting the blade and a table for stacking sheets are installed instead of the winder.

In a particular embodiment of the invention, the line may further comprise a clamping shaft (13) for pressing the initial film to the material covering it before second clearance. Also, additional unwinding units may be provided in the line for supplying additional films to the third or subsequent calender clearances (not shown).

 When implementing the inventive method, the extruded molten polymer material, with a temperature of about 200 - 300 ° C, is fed from above to the first (upper) gap between the upper (4) and middle (5) calendars, in which it is molded and partially cooled to form a plastic polymer coating layer (14) in the form of a canvas. Next, the covering layer (14) goes around the middle calender (6) and falls into the second gap formed by calendars (5) and (6). By means of the drum (10), the initial film (1) is fed into the specified second gap, so that it essentially covers the lower calender (6) in the specified and one side directly contacts the surface of this calender (6). In this case, the coating layer (14) heated to a temperature of about 150-230 ° C is in contact with the other side of the specified film (1) (in particular, passes above it).

 Thus, in the second calender gap, the polymer coating layer (14) is joined to the film surface (1) and smoothed out. In this case, due to the contact of the initial film (1) with the lower calender, which ensures its cooling, it does not overheat due to the coating layer (14), which prevents deformation of the film (1), in particular its functional or decorative layer (3). The temperature of the calendars is, as a rule, from 25 to 130 ° C and depends on the material of the starting film and the extrudable material.

 To improve the adhesion of materials before feeding into the second gap, the original film (1) can additionally be pressed to the covering polymer layer (14) by means of a clamping shaft (13). In particular, the layer (14) and the film (1) can be clamped between said shaft (13) and the middle calender (5).

 After passing through the second calender gap, the resulting material can be fed into one or more calender clearances for additional smoothing (not shown in the drawings). It is also possible that an additional film can be fed into the third or subsequent calender gap, which is connected by a coating polymer layer (14).

 The finished multilayer material (11) is wound into a roll by means of a winder (12) or cut into sheets and stacked on a table.

As the materials of the coating layer (14), any polymer material having adhesion to the material of the starting film (1) can be used, in particular polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC) and others. The thickness of the coating layer (14) is preferably from 150 to 1000 microns.

 It should be noted that the coating layer (14) can be applied both to the surface of the support layer (2) of the original film (1) and to the surface of the non-polymer or functional layer (3) (see Fig. 2). In both cases, the geometry of the layer (3) will be preserved.

 In addition, the claimed method can be applied several coating layers. It is also possible to use a line having a larger number of calendars to increase the smoothness of the resulting multilayer material (11).

Example 1

 According to the claimed method, a rolled laminate having the configuration shown in FIG. 2c and containing sequentially placed layers:

 1. The support layer (2) of high pressure polyethylene (LDPE) with a thickness of 40 μm,

2. Non-polymer decorative layer (3) in the form of a print layer (ink) thickness of about 10 microns,

 3. The support layer (2) of biaxially oriented polypropylene (B 01111) with a thickness of 25 μm.

 4. The covering layer (14) of polypropylene with a thickness of 200 μm

 The material was characterized by good adhesion of the layers and the absence of deformation of the decorative printed layer (3).

Example 2

 According to the claimed method, a sheet laminate having the configuration shown in FIG. 26 and containing sequentially placed layers:

 1. The support layer (2) of high pressure polyethylene (LDPE) with a thickness of 40 μm,

2. Non-polymer functional layer (3) in the form of a metallization layer with a thickness of about 1 μm,

 3. The covering layer (14) of polyethylene with a thickness of 300 μm.

 The material was characterized by good adhesion of the layers and the absence of defects in the metallization layer (3).

It should be noted that the invention is not limited to the embodiments described in the description. Other modifications are also possible. the proposed method in the framework of the above set of essential features. In particular, it is possible to obtain other combinations of material layers and their application modes.

Claims

Claim  1. A method of producing a multilayer sheet or roll material (11), comprising applying a polymer coating to the original film (1) having at least one supporting polymer layer (2) and at least one non-polymer functional or decorative layer associated with it (3 ),  moreover, when applying the coating, the molten extruded polymer material (9) is successively passed through at least two gaps of the cooling calendars, with the formation of a coating polymer layer (14) with a thickness greater than the thickness of the initial film in the first gap, and the initial gap is fed into the second or subsequent gap a film (1) with the connection of the coating polymer layer (14) and the original film (2),  at the same time, in the specified gap, one of the calendars (6) is covered by the initial film (1) with direct contact of the first side of the initial film (1) with the surface of this calender (6), and the second side of the initial film (1) with a covering polymer layer ( fourteen).  2. The method according to claim 1, in which the coating polymer layer (14) is applied from the side of the supporting polymer layer (2) of the original film (1).  3. The method according to claim 1, in which the coating polymer layer (14) is applied from the non-polymer decorative or functional layer (3) of the original film (1).  4. The method according to claim 1, in which the molten extruded polymer material (9) is passed through at least three gaps of the cooling calendars, and an additional film is fed into the third or subsequent gap of these calendars to ensure its connection with the coating polymer layer (14).  5. The method according to claim 1, in which three calendars (4,5,6) are used, placed vertically or at an angle, the first calendaring gap is formed by the upper (4) and middle (5) calendars, and the second calendaring gap is the middle (5) and lower (6) calendars, moreover, when coating is applied, they provide coverage of the initial film (1) of the lower calender (6).  6. The method according to p. 1, in which, before applying the original film (1) to the second calender gap, it is pressed against the covering polymer layer (14) by means of a clamping shaft (13). 7. The method according to any one of claims 1 to 6, in which an initial film (1) is used, in which the supporting polymer layer (2) is made of polyethylene or polypropylene, or polyethylene terephthalate. 8. The method according to any one of claims 1 to 6, in which an initial film (1) is used, in which the non-polymer decorative or functional layer (3) is a printing layer and / or a barrier layer and / or a reflective layer.  9. The method according to any one of p. 1-6, in which, as a covering polymer layer (14), a layer of polyethylene or polypropylene, or polyethylene terephthalate, or polystyrene, or polyvinyl chloride is applied.  10. The method according to p. 4, which use an additional film made of polyethylene or polypropylene, or polyethylene terephthalate  11. The method according to any one of p. 1-6, which uses the original film (1), in which the thickness of the support layer (2) is 10-100 microns.  12. The method according to any one of p. 1-6, in which the original film (1) is used, in which the thickness of the non-polymer functional or decorative layer (3) is 1-50 microns.  13. The method according to any one of p. 1-6 in which the coating polymer layer (14) is applied with a thickness of 150-1000 microns.  14. The method according to any one of p. 1-6, in which, when coating, the temperature of the calendars (4,5,6) is 25 - 130 ° C  15. The method according to any one of p. 1-6, in which when coating the molten extruded polymer material (9) has a temperature of 200 - 300 ° C, and the coating polymer layer (14) when fed into the second calender gap has a temperature of 150 -230 ° C.