This application is a 371 of PCT/IB2014/058157, filed Jan. 9, 2014, which claims the benefit of Italian Patent Application No. FI2013A000010, filed Jan. 11, 2013, the entire disclosure of each of which is incorporated herein by reference.
The invention generally refers to the field of plants and equipment for processing yieldable material such as paper, fabric, leather, plastic bands, paper sheets, films, and in particular for obtaining embossed designs or decorative patterns thereon through embossing processes, especially in the paper tissue industry for producing paper napkins, paper handkerchiefs, toilet papers, paper towels and similar products.
A production line of the conventional type in the paper tissue industry for obtaining embossed products such as the aforementioned ones, is schematically illustrated in
As known to those skilled in the art, embossing in the aforementioned products not only serves a decorative purpose, but also contributes to keep the webs which form these products together. This aspect, i.e. the capacity of the webs to remain joined together during use, is important for determining the quality of the product. The adhesive effect between the webs however depends on the type of paper used, and with less soft and yieldable paper, which may advantageously be used for obtaining less expensive products, this effect reduces remarkably, hence the structure of the end product is unstable. In these cases the use of a bonding agent suitably distributed between the webs in the areas subjected to embossing may help overcome the problem, but the current production lines do not allow a selective distribution of the bonding agent which would end up inevitably deposited even in the non-embossed areas thus stiffening the end product and deteriorating the quality thereof. The need for ensuring high adhesion of the webs also affects the maintenance of the embossing equipment. Actually, ensuring high quality standard as far as the adhesion of the webs is concerned, requires maintaining high pressure between the two metal cylinders, hence leading to quick wear of the same and the need of having to replace them often (usually every six months), thus increasing the production costs. A similar problem arises should one want to selectively print a coloured drawing or motif, a writing or anything else on the non-embossed areas or on the embossed areas of a product. Even in this case the current production lines do not allow for selectively printing the embossed areas or the non-embossed areas, in normal cases the embossed areas of the product completely surrounding the non-embossed areas.
The general object of the present invention is to provide a plant for the production of embossed articles capable of allowing the distribution of glue or of a design print, decorative patterns, writings or anything else on selected areas of such products.
A particular object of the present invention is to provide a plant of the aforementioned type for the production of paper handkerchiefs or napkins, capable of allowing perfect adhesion of the webs without jeopardizing the softness thereof and regardless of the type of paper used, thus having a positive impact on the production costs.
Another object of the present invention is to provide a plant of the aforementioned type capable of allowing selective printing in areas of the product being processed and capable of increasing the possible combinations of printings with respect to the currently available systems.
Another object of the present invention is to provide a plant of the aforementioned type, in which the wear of the embossing cylinders is lower with respect to what occurs in known plants, thus reducing the stop times for maintenance, and the production costs.
These objects are attained through the plant for the production of embossed articles according to the present invention whose essential characteristics are indicated in claim 1. Further important characteristics are indicated in the dependent claims.
According to an important characteristic of the invention, upstream of the embossing group there is provided a glue dispensing unit and/or a printing unit comprising at least one cliché roll, for the application of the glue on a web of the band, or of the ink on said band, said web or band being moved between the cliché roll and a second contrast cylinder. Actuator means are further provided for driving close or away to each other at least one portion of the cliché roll from the second contrast cylinder as a function of the position of the in-relief design on the surface of the pressing cylinder of the embossing group.
According to particular embodiments of the invention the actuator means may be of the mechanical type, with cam and lever, or of the electronic type, for example with an encoder.
According to another important characteristic of the invention, the cliché roll comprises at least one fixed portion and at least one mobile portion, both linked with driving means that bring the portions into rotation, the at least one mobile portion being linked with the actuator means for approaching/moving away the at least one mobile portion of the cliché roll from the second contrast cylinder.
In a preferred solution of the invention the cliché roll is mounted on a first support adapted to pivotally support the end fixed portions of the same roll, the at least one mobile portion of the cliché roll being interposed between the fixed portions and being integral with a shaft resting on a second support, coaxial with the cliché roll and linked with the actuator means.
In a particular embodiment, the shaft is rotated by first driving means and the fixed portions of the cliché roll are rotated by third driving means that via said shaft are linked to second driving means.
According to another preferred embodiment of the invention the cliché roll comprises at least two mobile portions arranged between the fixed end portions and separated by a corresponding intermediate fixed portion, which is pivotally mounted on a third support coaxial with the shaft and driven thereby through fourth driving means.
In a particular embodiment of the invention the fourth driving means comprise an auxiliary transmission shaft pivotally connected to the first and to the third support and parallel to the shaft of the cliché roll.
These and other characteristics and advantages of the plant for the production of embossed articles according to the present invention shall be apparent from the following description of an embodiment thereof provided purely by way of non-limiting example with reference to the attached drawings wherein:
With reference to
According to the invention, upstream of the embossing group 14 there is provided a glue dispensing unit generally indicated with 17. The unit 17 comprises a glue application device 20 and two deviation rolls 18 and 19 each of which are fed respectively with one or more webs, generally indicated with Na and Nb that are obtained through internal separation of the band N exiting from the roller press 13 upstream of the glue group 20. The webs Na and Nb are supplied to a second contrast cylinder or roll 21 downstream of the glue group 20. As shown in further detail in
Still according to the invention, the position of the cliché roll 20b with respect to the contrast cylinder 21 is controlled by the embossing group 14 as a function of the angular position of the pressing cylinder 14a through an actuation device, schematically indicated with 11 in
The profile of the cam 23 is designed as a function of the presence/absence of smooth portions on the surface of the cylinder 14a, portions intended to obtain non-embossed areas (for example the areas indicated with 8 in
Generally speaking, the cam may simply define alternating areas where gluing or printing is to be obtained. Instead of a mechanical cam, it can be an electronic cam defined by a specific mathematical law. For example, the cylinder 14a of the embossing group 14 can be associated to an angular position transducer adapted to generate signals as a function of the detected angular position of the same cylinder. The signals are exploited to control a suitable actuator causing the displacement of the cliché roll as described above.
Depending on the distribution of the embossed areas with respect to the non-embossed areas on the finished product, the cliché roll may acquire various configurations, four of which are exemplified in figures from 4 to 9.
In
The drive is transmitted from the axis of the contrast cylinder 21 to the axis of the cliché roll 20b through first drive means 27, for example of the gear type, while second drive means 28, for example of the belt type, transmit motion from the axis of the cliché roll 20b to the axis of the anilox roll 20a. The axes of the anilox roll 20a and of the cliché roll are also linked through the extendable support arm 26. At least one of the ends of the axis of the cliché roll 20b is linked with the active end of the linkage 25, hence, following the movement of said linkage induced by the rotation of the cam 23 integral with the pressing cylinder 14a of the embossing group 14, the cliché roll 20b is subjected to a cyclic angular displacement around the axis of the anilox roll 20a, to which it is linked via the extendable arm 26.
In
The cliché roll 20b is supported by a pair of fixed support uprights 32 carrying, at an end, two coaxial sleeves 33, on which there are pivotally mounted two hollow shafts 34a and 34b coaxial and opposite to each other carrying the fixed end portions 31 of the cliché roll 20b. The two hollow shafts 34a and 34b are brought into rotation by third drive means 35 and 36 arranged between the axis of the anilox roll 20a and the axis of the cliché roll 20b at the two ends of the latter. In this way, the fixed end portions 31 of the cliché roll 20b are brought into rotation. A shaft 42 brought in rotation by the first drive means 27 is arranged coaxial to the hollow shafts 34a and 34b. The shaft 42 is integral with the mobile intermediate portion 30 of the cliché roll 20b and the ends thereof are connected to the linkage 25. Hence, upon control transmitted by the embossing group 14, the intermediate portion 30 of the cliché roll 20b moves in the direction of the arrow F. In the contact position thereof, the cliché roll 20b rests on rotatable supports 44 fixed to the structure and serving as an abutment.
In the embodiment illustrated in
The cliché roll 20b is supported by a pair of fixed support uprights 32 carrying—at one end—two coaxial sleeves 33, on which there are pivotally mounted two coaxial and opposed hollow shafts 34a and 34b supporting the fixed end portions 31 of the cliché roll 20b. The two hollow shafts 34a and 34b are brought into rotation by third drive means 35 and 36 arranged between the axis of the anilox roll 20a and the axis of the cliché roll 20b at the two ends of the latter. In this way the fixed end portions 31 of the cliché roll 20b are brought in rotation.
The fixed intermediate portion of the cliché roll 20b is rotationally driven around a sleeve 37, coaxial to the two hollow shafts 34a and 34b, rigidly supported by a fixed upright 38. The rotation of said intermediate portion is driven by an auxiliary drive shaft 39, parallel to the cliché roll 20b and pivotally supported by uprights 32 and 38, through transmission means 40 arranged between the shaft 39 and the intermediate portion. The rotation of the shaft 39 is driven through fourth drive means 41 controlled by a shaft 42 internal and coaxial to the sleeves 33 and rotated by the first drive means 27 which receive motion from the axis of the contrast cylinder 21. Motion is transmitted to the anilox roll 20a through the second drive means 28. The extandable arm which connects the anilox roll 20a to the cliché roll 20b is indicated with 26.
The internal shaft 42 is linked to the mobile portions 30 of the cliché roll 20b to bring them into rotation and move them in the direction of arrow F upon control transmitted by the embossing group 14 through the aforementioned cam and lever mechanism (or an equivalent mechanism); linkage end arms 25 are connected to the shaft 42. In order to allow the aforementioned movement of the shaft 42, the latter is engaged with sufficient clearance in the support 37 and in the contact position thereof it rests on abutment rotatable supports 44 fixed with respect to the structure of the group.
A cliché roll in this configuration allows for spreading the glue on entire crosswise strips of the web, when the mobile portions 30 are coaxial with the fixed portions 31 of the cliché roll, and the application of glue on three longitudinal strips of the web, when the mobile portions 30 are displaced angularly with respect to the fixed portions 31.
The variant embodiment of the cliché roll 20b, illustrated in longitudinal section in
The glue dispensing unit 17 and the printing unit 50 are of the conventional type and thus they may be of the doctor blade type, as provided for above, or of any other type, for example with nozzles.
In particular, also the anilox roll 20b may be obtained as several coaxial portions thus allowing, in case of printing, using black ink or ink of any other colour, given that the single blade groups, containing ink, can be supplied with various kinds of ink coming from different pumps. This variant embodiment of the invention is not illustrated in further detail, being it is easily understandable to the skilled person from what has been described above.
In an even further embodiment of the invention, schematically shown in
Even the anilox roll 20a may be obtained in several units or independent sectors. This variant, schematically shown in
A plant intended to produce articles such as paper napkins or handkerchiefs and the like tissue articles has been described above. Should the plant be used for producing toilet paper or paper towel and the like, the folding unit 16 is replaced by a rewinder for forming rolls.
Although the present description has made reference to embossed articles of the paper or tissue converting industry, it is clear that the plant according to the invention can be used, when suitably adapted, even for articles that require embossing in the textile industry or in other fields.
The plant for the production of embossed articles according to the present invention can be subjected to variants and or modifications without departing from the scope of protection of the invention as defined in the following claims.
Number | Date | Country | Kind |
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FI2013A0010 | Jan 2013 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2014/058157 | 1/9/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2014/108853 | 7/17/2014 | WO | A |
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3741851 | Erb et al. | Jun 1973 | A |
7384505 | Zoller et al. | Jun 2008 | B2 |
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20100163194 | Sauter | Jul 2010 | A1 |
20100181040 | Perini | Jul 2010 | A1 |
20140371043 | Perini | Dec 2014 | A1 |
Entry |
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International Search Report and Written Opinion issued in PCT Application No. PCT/IB2014/058157 mailed Apr. 24, 2014 (9 pages). |
Number | Date | Country | |
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20150354138 A1 | Dec 2015 | US |