Title of Invention

A MELT BLOWN DEVICE FOR THE PRODUCTION OF MELT BLOWN PRODUCTS

Abstract

Melt blown device for the production of melt blown products, being provided with a nozzle (1) releasing filaments (3), with a continuously movable deposit screen (5) being arranged below the nozzle (1), onto which screen the filaments for the melt blown product can be deposited. A suctioning device for suctioning air through the deposit screen (5) is provided at the deposit screen. In its longitudinal direction, the deposit screen is provided with several suctioning areas (6,7,8,9) separated from one another. One of these suctioning areas is a primary suctioning area (8) allocated the deposit region. In the suctioning areas the suctioning speeds can each be adjusted independently from one another.

Full Text

The invention relates to a melt blown/device for the production of melt blown products by way of a nozzle releasing filaments, with a continuously moveable deposit screen being provided underneath of the nozzle, onto which the filaments for the melt blown product can be deposited, and a suction device for suctioning air through the deposit screen being provided at the deposit screen. In a melt blown arrangement and/or during the melt blown process the polymer melt released from the nozzle is impinged by blast air flow. This causes the melt to form polymer fibers, which subsequently are deposited on the deposit screen for the melt blown product. In the melt blown arrangements of the type mentioned on the outset and known from practical operation, which the invention is based upon, only a single suctioning channel and/or suctioning area is provided in the deposit region of the filaments, to which a suctioning blower is allocated below the deposit screen. From the arrangements known, frequently melt blown products are yielded that are provided with undesired irregularities and/or inhomogeneities. In the suctioning area and/or in the region of the deposit screen of these melt blown arrangements known, frequently a more or less intense floating of fibers occurs, causing an uncontrolled deposition of the fibers and, thus, irregularities in the melt blown product. In particular, these irregularities relate to the product thickness, the air permeability, and the ratio of lateral strength / longitudinal strength of the fiber mat produced as well as to irregularities in the surface of the melt blown product. As a result, the product quality of the melt blown product is lower than desired. In contrast thereto, the invention is based on the technical problem to provide a melt blown arrangement of the type mentioned on the outset, by which melt blown products can be produced that are characterized in homogeneity and evenness with regard to their characteristics, and, in particular, i which are provided with an optimal surface quality as well. The object $# to primarily enable the production of melt blown products, which are provided with a consistent product thickness and a constant ratio of lateral strength / longitudinal strength. The air permeability shall also be as consistent as possible on various placee of the melt blown product. In order to solve the above-mentioned technical problem the invention teaches a melt b'lown arrangement of the type mentioned on the outset, characterized in that, in its longitudinal direction, the deposit screen is provided with several suctioning areas, independent from one another, one of these suctioning areas being a primary suctioning area allocated to the deposit region, and the suctioning speed in the individual suctioning areas can be adjusted independently from one another. The travel direction and/or transportation direction of the deposit screen characterizes the longitudinal direction of the deposit screen. Therefore, the several suctioning areas separated from one another are arranged behind one another, seen- in Che travel direction and/or transportation direction of the deposit screen. The term deposit region defines the area of the deposit screen, onto which the majority of the filaments is deposited and/or onto which all or almost all of the filaments are deposited. In each of the suctioning areas the suctioning speed can be adjusted separately and independently from the other suctioning areas. The suctioning speed defines the speed of the air auctioned through and/or to the deposit screen in m/s. The suctioning device and/or the suctioning blowers of the suctioning device is/are practically arranged below the deposit screen. The scope of this invention includes the fact that the nozzle releasing the filaments is embodies as a melt blown blowing head. Furthermore, the scope of this invention includes that the nozzle of the melt blown arrangement is provided with a multitude of jet holes and/or jet apertures arranged in a row for the release of polymer melt. Therefore, only a single row of jet apertures is provided. Furthermore, the melt blown arrangement according to the invention is preferably provided with a longitudinal nozzle for the release of tempered blast air, and this blast air impinges the polymer melt and/or the exiting filaments. Preferably, at least three suctioning areas, separated from one another, are provided behind one another in the longitudinal direction and/or in the travel direction of the deposit screen. Here, one of these suctioning areas is the primary suctioning area. According to a very preferred embodiment, which is of particular importance within the scope of the invention, four suctioning areas, separated from one another, are provided, and here, an initial suctioning area and a second suctioning area is provided in front of the primary suctioning area in relation to the travel direction of the deposit screen, and, additionally, a third suctioning area is provided here behind the primary suctioning area in the travel direction of the deposit screen. ThiB embodiment with four suctioning areas that are independent from one another, as proven particularly suitable within the scope of the invention. The scope of the invention includes the fact that the suctioning speed in the primary auctioning area is higher than the one in the other suctioning areas. Therefore, in the embodiment having four sucticning areas separated from one another, the auctioning speed in the primary suctioning area is higher than the suctioning speed in the first, second, and third suctioning area. It is advantageous for the suctioning speed in the primary auction area to be at least twice as high as the suctioning speed in each of the other suctioning areas. Preferably, the suctioning speed in the primary suctioning area is at least twice as high as the suctioning speed in the first suctioning area and/or in the second suctioning area. Preferably, the suctioning speed in the primary suctioning area is furthermore at least twice as high as the suctioning speed in the third suctioning area. According to a preferred embodiment of the invention, each suctioning area is provided with a suctioning blower c£ its own. Therefore, the suctioning device of the melt blown arrangement according to this embodiment is provided with several suctioning blowers. At each suctioning blower, the auctioning speed can be separately adjusted for each suctioning area. Therefore, an independent adjustment of the suctioning air flow occurs in each auctioning area. The auctioned volume stream can be adjusted absolutely independently from one another. Here, the adjustment can be performed with the condition that the auctioning power in the primary suctioning area is twice as high as the one in each of the other suctioning areas. Advantageously, the individual suctioning area are -separated from one another by means of limiting walls made from sheet metal. Here, preferably vertically oriented sheet metal is used. Vertically in this context includes essentially vertical as well. The invention is based on the finding that the deposit of a melt blown product and/or a non-woven web can be controlled via the melt blown arrangement according to the invention optimally and securely operating. With the embodiment according to the invention an undesired floating of fibers in the area of the deposit screen can be eliminated and/or efficiently reduced. By way of embodying the various suctioning areas a very homogenous fiber deposit can be achieved and, surprisingly, inhomcgeneities in the melt blown products deposited can be largely minimized. Disturbing sections of higher or lower thickness in the melt blown product produced are not observed. Additionally, disturbing inhomogeneities regarding the air permeability of the non- woven web or regarding the ratio of lateral strength longitudinal strength can be excluded. Furthermore, the primary auctioning area can be embodied shorter with respect to the longitudinal direction and/or the transportation direction of the deposit screen compared to the auctioning area provided in melt blown arrangements known from practical use. Thus resulting in advantageous energy savings, because the overall volume stream of suctioned air can be reduced. without the separation in various suctioning areas according to the invention a single suctioning area in the deposit region, requiring a high suctioning speed, had to be embodied with larger dimensions in the transportation direction of the depoait screen. Therefore, in the melt blown arrangements known an unnecessarily high volume stream is suctioned, which again calls for high energy expenses. In the following, the invention is explained in greater detail using accompaying drawings for demonstration only that show an exemplary embodiment. They show in a schematic drawing: Fig. 1 a side view of a melt blown arrangement according to the invention and Fig. 2 an enlarged section A of Fig. 1. The figures show a melt blown arrangement according to the invention for the production of melt blown products, namely of non-woven webs. The melt blown arrangement is provided with a nozzle 1 with the filaments 3 being extruded tnrough ice jet apertures 2. Advantageously, the nozzle 1 in the exemplary embodiment is provided with a row comprising a multitude of jet apertures 2. The filaments 2 are impinged by tempered blast air 4, its direction of flow being shown in the figures by way of corresponding arrows. Underneath of nozzle 1 a continuously movable deposit screen 5 is provided, onto which the filaments 3 for the melt blown non-woven web can be deposited. Air is suctioned through the deposit screen 5, so that the filaments 3 are more or less suctioned onto the deposit screen, According to the invention, the deposit screen 5 is provided with four suctioning areas 6, 7, 8, 9, separated from one another. One of these sauctioning area 6. 7, 8,9 is the primary suctioning area 8 allccated to the depcait region. The deposit region is defined by that area or. the deposit screen 5, on which at least the majority of the filaments 3 are deposited. According to the .nventicr., the suctioning speed in the suctioning areas 6. 7, 8,9 can each be adjusted independently from one another. The auctioning speed in the primary suctioning region 8 is nigher than the one in the other suctioning areas 6, 7, 9. Additionally, the auctioning speed in the second suctioninag area 7 is advantageously higher than the suctioning speed in the first, suctioning area 6. - According to a preferred embodiment of the invention, each suctioning area 6, 7, 8, 9 is proviced with a suctioning blower (not shown) of its own. Therefore, the suctioning speed for the respective suctioning area d. 7, 8, 9 can be separately adjusted at each suctioning blower and allows an independent control and/or adjustment the suctioned all flow in each sucticning are 6,7,8,9. Advantageously, in the exemplary embodiment the individual suctioning areas are separated from one another via limiting walla 10 made from sheet metal. In Fig. 2, in particular, the exiting filaments 3 and the flow direction of the blast air 4 and the flow direction of the suctioned secondary air 11 are discernible, as well. According to the invention, the separation in the individual auctioning areas 6, 7, 8, 9 and the direction of the blast air 4 as well as the direction of the secondary air 11 can be adjusted such that a very functional and homogenous deposit of the filaments is possible and, thus, surprisingly homogenous product characteristics can be achieved. According to the invention, the third suctioning area 9, arranged behind the primary auctioning area 8, serves for the effective contact of the melt blown product produced to the deposit screen 5. The invention is based on the knowledge that, without this third suctioning area 9, the melt blown product produced might be undesirably influenced by the secondary air suctioned by the blast air exiting with high speeds. The separation into the suctioning areas 6, 7, 8, 9 according to the invention minimizes disturbing and undesired influences of any air flow. WE CLAIM: 1. A melt blown device for the production of melt blown products, provided with a nozzle (1) releasing filaments (3), and below the nozzle (1), a continuously movable deposit screen (5) being arranged, onto which the filaments (3) for the melt blown product can be deposited, and with a suctioning device for suctioning air through the deposit screen (5) being provided at the deposit screen (5), characterized in that the deposit screen (5) in its longitudinal direction being provided with several suctioning areas (6,7,8,9), separated from one another, one of these suctioning areas (6,7,8,9) being a primary suctioning area (8) allocated at the deposit region, and that in the suctioning areas (6,7,8,9) the suctioning speeds can each be adjusted independently from one another. 2. Melt blown device as claimed in claim 1, wherein at least three suctioning areas, separated from one another, are provided. 3. Melt blown device as claimed in claim 2, wherein four suctioning areas (6,7,8,9), separated from one another are provided, and that an initial suctioning area (6) and a second suctioning area (7) are arranged in front of the primary suctioning area (8), with respect to the travel direction of the deposit screen (5) and that a third suctioning area (9) is provided behind the primary suctioning area (8), in the travel direction of the deposit screen (5). 4. Melt blown device as claimed in one of the claims 1 through 3, wherein the suctioning speed in the primary suctioning area (8) is higher than the one in the other suctioning areas (6,7,9). 5. Melt blown device as claimed in one of the claims 1 through 4, wherein each suctioning area (6,7,8,9) is provided with a suctioning blower of its own. 6. Melt blown device as claimed in one of the claims 1 through 5, wherein the individual suctioning areas (6,7,8,9) are separated from one another by means of limiting walls (10) made from sheet metal. Melt blown device for the production of melt blown products, being provided with a nozzle (1) releasing filaments (3), with a continuously movable deposit screen (5) being arranged below the nozzle (1), onto which screen the filaments for the melt blown product can be deposited. A suctioning device for suctioning air through the deposit screen (5) is provided at the deposit screen. In its longitudinal direction, the deposit screen is provided with several suctioning areas (6,7,8,9) separated from one another. One of these suctioning areas is a primary suctioning area (8) allocated the deposit region. In the suctioning areas the suctioning speeds can each be adjusted independently from one another.

Documents:

99-KOL-2003-(09-02-2012)-CORRESPONDENCE.pdf

99-KOL-2003-(09-02-2012)-PA-CERTIFIED COPIES.pdf

99-kol-2003-granted-abstract.pdf

99-kol-2003-granted-claims.pdf

99-kol-2003-granted-correspondence.pdf

99-kol-2003-granted-description (complete).pdf

99-kol-2003-granted-drawings.pdf

99-kol-2003-granted-examination report.pdf

99-kol-2003-granted-form 1.pdf

99-kol-2003-granted-form 18.pdf

99-kol-2003-granted-form 2.pdf

99-kol-2003-granted-form 26.pdf

99-kol-2003-granted-form 3.pdf

99-kol-2003-granted-form 5.pdf

99-kol-2003-granted-priority document.pdf

99-kol-2003-granted-reply to examination report.pdf

99-kol-2003-granted-specification.pdf

99-kol-2003-granted-translated copy of priority document.pdf