RU2776668C1 - Line for the production of sheet material, embossed with drive - Google Patents

Abstract

FIELD: embossed sheet material production.

SUBSTANCE: invention relates to the production of register embossed sheet material. The laminating and embossing production line includes an unwind section including unwinders for component webs to be laminated one on top of the other to form sheet material. Wherein the components of the web include at least the lower web and the upper web, as well as one or more intermediate webs. The production line also includes a section for laminating component webs to form sheet material and a continuous embossing section with register located below the lamination section in the material direction and including at least one engraved embossing cylinder. Wherein the lamination section is configured to provide registered embossing on the sheet material passed through the gap between the engraved cylinder and the counter cylinder. The production line also includes a lacquer section positioned above the lamination section in the direction of material flow and configured to apply lacquer to the top web prior to laminating it with other webs to form sheet material.

EFFECT: invention increases surface accuracy and quality without compromising line performance.

12 cl, 7 dwg

Description

Technical field

The invention relates to a production line for laminating and embossing, designed to continuously produce sheet material (product) embossed with register.

State of the art

The term "register embossed sheet" refers to a product in the form of a web, usually composed of two or more layers, with an embossed surface that is accurately positioned in relation to the printed image or pattern (hereinafter "print"). The combination of a high quality print and register embossing results in a look very similar to natural high value materials such as wood. Accordingly, such materials are very interesting for the manufacture of floor coverings or decorative panels.

Sheet material consists of two or more component webs. The constituent webs may include, for example, a base layer, a printed layer, and a transparent top layer. Alternatively, the print may be made on the reverse surface of the transparent layer. The component webs may be made of PVC or other suitable materials. Depending on the materials used, the resulting web may be stretchable. The thickness of the resulting sheet material is typically in the range of a few hundred microns, for example 0.5 mm, to about 1.0-1.5 mm.

In a so-called continuous laminating and embossing production line, the constituent webs are laminated to produce a multilayer sheet material which is embossed by passing through a gap between an appropriately engraved embossing cylinder and a counter cylinder (press cylinder). This technology is also called rotary embossing. The main advantage of such production lines is their ability to operate continuously, resulting in greater throughput compared to a batch system in which panels of sheet material are cut and embossed individually on each panel. However, rotary embossing requires careful alignment of the engraved cylinder with the material.

Various technologies are used to maintain proper alignment of the engraved cylinder with respect to the fast moving sheet material. Suitable techniques for continuous register embossing are described, for example, in EP 2447064 and EP 2636524. As a rule, known techniques use sensors for the position of the engraved cylinder and the corresponding alignment marks on the material, and if necessary, adjust the position of the cylinder or control the stretching of the sheet material to restore synchronization with the cylinder.

As already mentioned, register embossing of the sheet material can provide a high quality surface finish. However, the industry requires constant improvement, for example, special surface finishes may be required, for example, to obtain a matte or silky surface. In addition, in some cases it is required to obtain a material for a special application. Now special surface treatment or obtaining other specified material characteristics is carried out using separate installations, so that the advantage of high productivity and speed is partially lost. In addition, running parts of the manufacturing process on separate plants requires moving materials between them and adjusting the appropriate equipment, which is time consuming and can reduce accuracy and quality. The use of separate installations increases the waste associated with the movement of the respective reels.

Accordingly, there is still a need to improve the technical means of production lines for the continuous production of register embossed sheet material.

Disclosure of invention

It is an object of the present invention to provide a laminating and embossing production line for the production of register embossed sheet material with improved versatility, and especially designed to provide custom material finishes without sacrificing the high productivity typical of continuous laminating lines.

This goal is achieved in the lamination and embossing production line according to claim 1 of the claims.

The production line is designed for laminating two or more webs, which are joined to form a sheet material, followed by embossing the resulting material. The lamination step is performed continuously by passing the laminated webs through a gap between one or more pairs of cylinders. The embossing step is also continuously performed by passing the sheet material between a suitable pair of cylinders, including an engraved embossing cylinder and a counter cylinder.

The laminating and embossing production line according to the invention comprises: an unwinding section for unwinding the constituent webs from which the sheet material is obtained; a lamination section configured for (capable of) laminating the constituent webs forming the sheet material; and a continuous register embossing section. The production line also includes a coating section which is located in line below the unwind section and above the laminating section, in the material direction, and is configured to coat the top web prior to laminating it with other webs to form sheet material.

The lacquer section is positioned in line so that the lacquering process can be carried out continuously if required and is fully integrated into the overall sheet production process.

The production line according to the present invention can optionally (optionally/necessarily) also be provided with a primer coating section and/or a protective film application section, after embossing. These additional sections are also integrated into the line so that they can be operated continuously if required.

Thus, the present invention provides a laminating and embossing production line that is capable of producing sheet material according to individual customer requirements. An important advantage of the invention is that the process of applying the lacquer, and if necessary applying a primer coat and a protective film, is carried out directly in the production process without the need to transfer the material to separate machines. That is, the shortcomings associated with such a transfer have been eliminated. For example, the production line of the present invention may perform steps that are typically performed on at least three separate machines in prior art manufacturing processes. One of the advantages of performing the entire production process on one line is a significant reduction in waste.

Detailed description of the invention

Below is a more detailed description of the invention.

The unwind section includes unwind machines (uncoilers) for the component webs to be laminated one on top of the other to form sheet material. The term "sheet material" refers to material consisting of two or more layers, each layer being formed by one of the constituent webs supplied from unwinders. Typically, such sheeting may comprise a backsheet, a printed film, and a coversheet, in that order from bottom to top. In some embodiments, the cover layer is a transparent film with a print on the inner surface so that the print remains visible but is not exposed to the environment. In some embodiments, the interlayer may be a colored web. The overall appearance may be a combination of the color of the intermediate layer and the print made on the transparent top layer.

The top web may be directed to the coating section before being laminated with other layers to form a sheet material ready for the embossing process. Lacquer application may be provided to provide additional protection to the top surface of the sheeting and/or desired surface finish.

Coating section in the preferred embodiment includes a group of elements that provide rotational application of varnish. Such a group of lacquer application elements may include a bath containing liquid lacquer. Such a group may also contain two rotating cylinders arranged to apply varnish to the surface of the top sheet.

In particular, the first rotating cylinder is located above the bath and its lower part enters the bath in such a way that when the bath is suitably filled with liquid lacquer, the lower part of the cylinder is immersed in the lacquer and the lacquer can be captured by the cylinder as it rotates. The second rotating cylinder is located opposite the first cylinder at a small distance, so that a gap is formed between them. During operation, a thin layer of lacquer is captured by the surface of the first cylinder and applied to the web passing through the gap. A suitable doctor blade (scraper) can be used to remove excess varnish from the surface of the first cylinder.

The first cylinder and the second cylinder in different embodiments of the invention may rotate in the same direction or in different directions.

Preferably, a water-based varnish is used.

The varnishing section may also include a drying section located below the varnishing group in the direction of material flow. In the drying section, the polymerization (curing) of the varnish is carried out. The drying step is preferably carried out by exposing the varnished sheet material to UV radiation. Accordingly, the production line of the present invention may include at least one suitable UV emitter. After the drying step, the lacquer is fixed on the surface of the top web and it can be laminated with other component webs.

In another embodiment of interest, the production line of the present invention may include a primer coating section, such as a primer coating that improves the adhesion of the sheet material to the surface. The primer coating section is located below the embossing section in the material direction and is configured to apply a primer coat to the back surface of the sheet material after embossing.

The application of an adhesive primer is very important, for example, when the sheeting is intended to cover non-combustible medium density panels or the like. In such a case, the sheet material can provide a strong and durable bond to the underlying panel, and application of an adhesive primer coat is the preferred option. When using sheet material, the adhesive primer enhances the performance of the adhesive used to attach the material to the surface.

The primer coating section may also include a drying section for curing the primer coat after it has been applied to the back surface of the sheet material.

In another embodiment of the invention, the laminating and embossing production line may include a section for applying a protective film to the top surface of the embossed sheet material. The advantage of the applied protective film is that it protects the upper surface of the material from damage, such as scratches. It should be noted that the top side is a valuable surface of the material since it is embossed and the print on the underlying layer is visible through it. Damage to the top surface can degrade overall quality and should therefore be prevented. The protective film is preferably provided with a suitable adhesive on its inside to interact with the sheet material. The adhesive composition makes it easy to apply the film to the sheet material, while at the same time the user can easily remove it when installing the finished sheet material, for example, on any piece of furniture.

The protective film application section is preferably located below the above-described primer coating section in the direction of material flow.

In the most preferred embodiment, the production line of lamination and embossing may include all of the above sections. Thus, a lacquer is applied to the top web, then it is laminated with two or more other webs to form a sheet material; register embossing of the thus obtained sheet material; after embossing, a primer coat is applied to the reverse side of the embossed sheet material; and after applying the primer coat, a protective film is applied to the upper surface of the sheet material. All the above steps are performed on the same line in continuous mode.

The production line of the present invention may include guiding means configured to selectively feed the top web into the coating section, or to feed the top web directly into the laminating section, bypassing the coating section. Thus, the production line can be reconfigured for optional lacquer application, if necessary.

The primer coating section and the protective film application section can also be configured for optional use, if required. Thus, the production line can be completely reconfigured according to the customer's request.

The production line according to the invention may also contain an end section in which the finished sheet material is accumulated. In one embodiment, the end section includes a winder for winding finished sheet material onto bobbins. Alternatively, the end section may include a cutting group for cutting the sheet material into sheets of a predetermined size, such as rectangular sheets. In general, bobbins may be preferred due to their compactness and also because the material can accumulate quickly and continuously. However, in some cases it may be preferable to cut the material to form sheets in order to avoid bending the material.

The indication "finished sheet material" refers to the sheet material after embossing and after the optional steps of applying an adhesive primer and/or a protective coating film.

The embossing section can be implemented in accordance with known technologies, and therefore it is not necessary to describe it in detail in order to understand the present invention. The embossing technology can be selected according to the characteristics of the sheet material, especially whether the material is rigid or stretchable. Various register embossing technologies can be incorporated into the production line of the present invention. It is most preferred to use embossing performed in accordance with the patented technology disclosed in the aforementioned patents EP 2447064 and EP 2636524.

In general, register embossing is performed based on a detected offset error in the angular position of the engraved embossing cylinder relative to the print on the sheet material being fed and making an appropriate correction. The error can be determined by measuring the angular position of the engraved cylinder and reading the alignment marks of the material. The alignment marks can be read, for example, by optical means. The error can be corrected by acting on the cylinder or by controlled stretching of the sheet material, if possible.

For example, in one exemplary embodiment, the embossing section includes at least one sensor for detecting the position of an engraved cylinder and at least one sensor for detecting alignment marks on the sheet material, as well as an adjustment system for adjusting the position of the engraved cylinder relative to the sheet material to maintain accurate registration based on the signals provided by the sensors.

In another exemplary embodiment, the embossing section includes means for providing controlled stretch to the sheet material, the amount of controlled stretch being determined to maintain accurate register between the engraved cylinder and the sheet material. Controlled stretching can be performed when the sheet material is in a heated state in which plastic deformation is facilitated.

In some embodiments, the engraved cylinder may create a alignment mark on the sheet material, and measurement (eg, optical reading) of the position of the mark relative to the print provides a determination of the position error (offset) of the cylinder.

It should be noted that "upstream" and "downstream" (or "before/after") refer to the order in which the various steps in the manufacturing process are performed.

Also disclosed is a method for continuous production of embossed sheet material with register on a laminating and embossing production line, the method comprising:

unwinding the component webs from their respective reels, including at least a bottom web and a top web, and optionally one or more intermediate webs;

laminating the constituent webs to form sheet material;

performing continuous register embossing on the sheet material by passing it through a gap between the engraved embossing cylinder and the counter cylinder;

wherein the method also includes the step of applying varnish to the top web by passing the top web through a gap between the coating cylinder and the counter cylinder, and the varnishing process is performed before laminating the top web with other webs to form a sheet material.

The method can be carried out on a lamination and embossing production line in accordance with the various options described in this application. In particular, the method may include applying a primer coating and/or applying a protective film on top, as already described.

Brief description of the drawings

The invention will be described below with reference to the figures, which show:

in fig. 1 is a simplified diagram of a laminating and embossing production line for producing embossed sheet material according to the first embodiment of the invention;

in fig. 2 is an enlarged view of the coating section of the laminating and embossing line of FIG. one;

in fig. 3 is an enlarged view of the embossing section;

in fig. 4 is an enlarged view of the adhesive primer coating section;

in fig. 5 is an enlarged view of the top film deposition section;

in fig. 6 is a diagram of a production line according to a second embodiment of the invention;

in fig. 7 is an enlarged view of the end section of the production line of FIG. 6.

Embodiments of the present invention will be described below. In FIG. 1 shows the following main parts: 1 - unwinding machine for the bottom sheet 11; 2 - unwinding machine of the intermediate web 12; 3 - unwinding machine of the upper web 13; 4 - varnishing section; 5 - lamination section; 6 - embossing section; 7 - cooling section; 8 - section for applying a primer coating; 9 - section for applying a protective film coating; 10 - winding group of the finished material; 11 - bottom canvas; 12 - intermediate canvas; 13 - upper canvas; 13' - upper canvas with applied varnish; 14 shows a pre-embossing sheet formed from a bottom web 11, an intermediate web 12 and a varnished top web 13'; 15 - sheet material with embossing; 16 - sheet material with an adhesive primer coating; 17 - protective covering film; 18 - finished sheet material coated with a protective film 17; 19 - reel with finished material.

Unwinders 1, 2 and 3 each have a feed reel and a spare reel ready for replacement. For example, on the unwinder 1, a reel 20 with the source material and a spare reel 21 are installed.

Webs 11, 12 and 13 are designed to form a 3-layer sheet material, which is embossed in section 6. Before laminating with other webs, the top web 13 is sent to the varnishing section 4, where a varnish is applied to the upper surface of the web 13.

For example, the bottom web 11 is a colored PVC web; the intermediate web 12 is a colored PVC web; and the top sheet 13 is a transparent PVC sheet printed on the reverse side. In other embodiments, the print may be applied to the intermediate web 12.

A preferred variant of the coating section 4 is shown in FIG. 2. Varnishing section 4 includes: 22 - varnishing device; 23 - bath for liquid varnish; 24 - coating cylinder of the device 22; 25 - counter cylinder device 22; 26 - doctor blade (scraper) for removing excess varnish from the coating cylinder 24; 27 - UV lamp for drying; 28 - guide rolls.

The top sheet 13 is guided through a narrow gap between the coating cylinder 24 and the counter cylinder 25. The coating cylinder 24 is partially immersed in the bath 23 so that, as it rotates, it picks up some varnish from the bath, forming a layer on the surface of the cylinder. The scraper 26 removes excess varnish from the surface of the cylinder 24 and this varnish falls back into the bath.

The top web 13 is guided into the nip with the top surface 131 facing the coating cylinder 24 so that varnish is applied to this top surface 131.

It can be noted that the rotation of the counter-cylinder 25 is determined by the web transport direction, for example clockwise in FIG. 2. Coating cylinder 24 can rotate in the same direction as the counter cylinder 25 or in the opposite direction, allowing the varnish to be applied in the forward or reverse direction.

In the example shown in FIG. 2, the coating cylinder 24 rotates counterclockwise to apply varnish in the forward direction, so that the varnish is collected on the right side of the cylinder where the scraper 26 is installed.

Coating cylinder 24 may have a suitable surface pattern to improve the efficiency of coating application. The counter cylinder 25 preferably has an elastomeric coating.

Bath 21 is connected to a suitable liquid lacquer reservoir (not shown) and may be provided with suitable means for maintaining a controlled level of lacquer.

Below the varnishing device 22, in the direction of travel of the web, the upper surface 131 is exposed to radiation from a UV lamp 27 to polymerize the varnish. The lacquered web 13' exits section 4 and is directed to the laminating section 5 where it is laminated with webs 11 and 12.

The lamp 27 is preferably an excimer lamp.

Preferably, the sections are arranged in a line, except for the coating section 4 above all sections, as shown in FIG. 1. However, other configurations are possible in the present invention.

In FIG. 3 shows a laminating section 5 and an embossing section 6. In the laminating section 5, the lacquered top web 13' emerging from the section 4 is laminated to the webs 11 and 12 by two counter-rotating rolls 30, 31 to form a sheet material 14.

Before being fed into the laminating section 5, the webs must be properly aligned with each other in a direction transverse to the main transport direction. The alignment of the webs 11 and 12 can be done by adjusting the position of the unwinders 1 and 2. The alignment of the top web 13 can be done by adjusting the position of the coating section 4.

Sheet material 14 is passed through a group of small rolls in section 32 of the heating. This heating section 32 brings the sheet material to a temperature suitable for the embossing process. The rolls of section 32 can be rotated at a variable speed to provide controlled stretch to the material 14. The controlled stretch is determined to maintain synchronization with the embossing process and provide the desired embossing with precise registration. The adjustable stretch can be calculated based on the detected offset error, for example, using sensors that determine the position of the engraved cylinder and the position of the alignment marks printed on the material.

The sheet material 14, after stretching, if necessary, is passed through the gap between the engraved cylinder 33 and the counter or press cylinder 34. The engraved cylinder 33 has a surface engraved in a suitable way to provide the necessary embossing on the sheet material 14. The embossed pattern corresponds to the print, provided on canvas 12.

The embossed material 15 is cooled in section 7 and sent to the primer coating section 8 (FIG. 4). In this section 8, an adhesive primer coat is applied to the reverse side 152 of the material 15. The application of the adhesive primer is carried out by two cylinders 40, with the lower cylinder picking up the liquid primer material from the bath 41. The principle of operation is similar to that of the coating device 22 described above.

After application of the adhesive primer coat, the material is dried in a suitable oven 42.

The sheet material 16 thus obtained is sent to the next section 9 where a protective film 17 is applied to the upper surface 161, which is an embossed surface, by means of two laminating rolls 50. The final sheet material 18 thus obtained with film 17 accumulates in section 10. After filling the reel, it can be removed and sent for storage.

Film 17 is preferably made of polyethylene. A suitable film thickness is, for example, 50 microns. The film 17 is provided with a suitable adhesive material on its inner surface 171.

The production line can be configured to optionally apply varnish, adhesive primer and protective film. In this way, customized material can be obtained.

In FIG. 6 and 7 illustrate a second embodiment of the invention in which the finished sheet material 18 is cut into individual sheets at a suitable end section 10a.

This end section 10a, shown in FIG. 7, contains cutting knives 60, the shape and dimensions of which provide cutting of individual sheets 61 of given sizes and shapes from sheet material 18. The material is directed to the cutting knives 60 by suitable guide rolls 63. After cutting, the sheets 61 are released by the output rolls 64 and placed in the store 62.

In the embodiment shown, the end cutting section 10a is positioned after the winding section 10 described above in the direction of material flow. The material 18, instead of being wound on reels, passes through the section and is fed into the cutting section 10a. This option can be used when there is no need to wind the material into rolls.

The invention meets the above objectives because the proposed production line is highly versatile and all steps are carried out continuously in the lamination process without regular interruptions or loading steps of the next batches of raw materials, which would slow down the entire process.

Claims (14)

1. A laminating and embossing production line for the production of register embossed sheet material in a continuous process, comprising: an unwinding section, including unwinding machines (1-3) for component webs (11-13) to be laminated one on top of the other to form the specified sheet material, and the components of the web include at least the bottom web (11) and the top web (13), and, optionally, one or more intermediate webs (12); a laminating section (5) configured to laminate the constituent webs to form the sheet material (14); a continuous register embossing section (6) located below the lamination section in the material direction of travel and including at least one engraved embossing cylinder, the laminating section configured to provide register embossing on the sheet material passing through the gap between the engraved cylinder and the counter cylinder; and a coating section (4) positioned above the lamination section in the material direction and configured to apply varnish to the top web (13) prior to laminating it with other webs to form a sheet material. 2. The production line according to claim 1, in which the varnishing section (4) contains a group (22) for applying varnish, including: a bath (23) for liquid varnish; a first rotatable cylinder (24) which is positioned above the bath, its lower part being immersed in the bath to pick up varnish therefrom as it rotates; a second rotating cylinder (25) located opposite the first cylinder at a close distance so that a gap is formed between them, wherein the first cylinder and the second cylinder are rotatable in the same direction or in different directions, and the coating section is configured to guide the upper web (13 ) through said gap so that the top surface (131) of the web faces the first cylinder. 3. The production line according to claim 2, in which the coating section also contains a polymerization section located below the varnishing group (22) in the direction of material flow. 4. Production line according to claim 3, in which the curing section includes at least one UV emitter (27) and is configured to expose the surface of the varnished web to the UV emitter radiation. 5. A production line according to any one of the preceding claims, comprising guiding means configured to selectively feed the top web into the coating section, or to feed the top web directly into the laminating section, bypassing the coating section. 6. The production line according to any of the preceding claims, further comprising a section (8) for applying a primer coating, such as an adhesive primer coating, to improve the adhesion of the sheet material to the surface, and this section (8) is located below the embossing section (6) in the direction material movement and is configured to apply a primer coat to the reverse surface (152) of the sheet material (15). 7. Production line according to claim 6, wherein the primer coating section (8) is configured to apply a liquid primer coat to the reverse surface of the sheet material and includes a bath (41) with a liquid primer coat, as well as two cylinders (40) rotating in opposite directions, with the lower part of one cylinder immersed in the bath to capture the liquid primer coating, and the other cylinder is the counter-cylinder, and the sheet material is passed into the gap between the cylinders. 8. A production line according to claim 6 or 7, wherein the primer coating section (8) includes a dryer section (42) for drying the primer coat after it has been applied to the sheet material. 9. Production line according to any one of the preceding claims, further comprising a section (9) for applying a protective film (17) to the upper surface of the embossed sheet material. 10. A production line according to any of the preceding claims, comprising an end section (10, 10a) in which finished sheet material (18) is accumulated and which includes: winding group, in which the finished sheet material (18) is wound on reels (19), and/or cutting group, in which the finished sheet material (18) is cut into sheets (61) of a given size. 11. The production line according to any one of the preceding claims, wherein the embossing section (6) comprises at least one sensor for detecting the position of the engraved cylinder and at least one sensor for detecting mounting marks on the sheet material, as well as an adjustment system for adjusting the position of the engraved of the cylinder relative to the sheet material in order to maintain accurate registration based on the signals provided by the sensors. 12. A production line according to any one of the preceding claims, wherein the embossing section (6) comprises means for providing controlled stretch to the sheet product, the amount of controlled stretch being determined to maintain accurate register between the engraved cylinder and the sheet material.

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