Patent Application
20070261541
The invention relates to a drum jacket for forming structures and/or relief patterns on a surface of a woven or nonwoven cellular material, fleece and/or woven or knitted textile by means of raised formations or structure elements on the drum jacket and a plurality of holes provided on the surface of the drum jacket for dewatering the drum jacket.
The document WO 2005/124001 describes a drum jacket for the creation of structures and relief patterns on the surface of a woven fleece by means of structure elements arranged in serpentines on a drum jacket having a plurality of holes arranged at random on the surface and in the depressions between the structure elements. Thus, the dewatering is insufficient, especially as far as the lower areas or the depressions are concerned, even more so since the holes are not oriented exclusively outward, that is radially of the drum jacket. A further disadvantage consists in the fact that the diameter of the holes is circular, so that a significantly higher number of circular holes are required in order to achieve a good dewatering effect than with the realization of the drum jacket according to the invention. Due to the circular holes, undesired bumps are formed on the surface. Moreover, the areas become unequal in their weight. As far as the arrangement of the holes is concerned, no preferred dewatering can be achieved; consequently, the dewatering is insufficient, particularly in the lower areas, since the holes are evenly spread over the whole surface.
It is an object of the invention to provide drum jackets, particularly surface-relief drum jackets for generating relief patterns on webs of fabrics or on nonwoven or woven fibers, i.e. a fleece, consisting of short but also of endless fibers such as synthetic staple fibers or also natural fibers, in such a manner that a perfect dewatering of the drum jackets is ensured.
The invention is solved according to the invention by the following features:
a) one or more holes are provided, at least in the raised formations or structure elements and/or in the lands between the raised formations or structure elements, having an essentially elongated cross-sectional shape or made elongated.
b) the long sides of the holes or midplanes of the holes extend across a movement plane or midplane of the drum jacket at an angle β between 20° and 170° or between 40° and 160° or between 80° and 100°.
Thus, a significantly more effective and directed dewatering of the drum jacket can be done and in addition wash-out of the fleece, in particular of the relief patterns formed on the fleece is avoided. The additional holes provided in the depressions are particularly suitable for thin-walled drum jackets that so far have been hard to dewater, particularly in the case of fleeces with very thin fibers, thick fibers and also short cellulose fibers or pulps. By means of the advantageous formation of the drum jacket with the plurality of holes in the structure elements and in the depressions, dewatering is optimized in a simple manner. Thanks to the use of narrow, elongated holes, less imprints are left on the surface of the fleece. Dewatering should not lead to a structuring or marking of the fleece. By means of the inventive elongated holes a smooth surface on the fleece is realized. Due to the elongated holes, a very large open surface with a very good dewatering is achieved, without having to face the disadvantages associated with circular holes. Furthermore, the holes are exactly aligned relative to the movement plane of the drum jacket in order to ensure an optimal dewatering effect. The fibers of the fleece are very strongly aligned longitudinally or on the movement plane of the fleece; thus, they do not fall as easily into the diagonal holes as it is the case when circular holes or holes which are basically parallel to the movement plane of the drum jacket are provided.
To this end it is advantageous that the raised formations or structure elements and the lands between the raised formations and structure elements form lower areas in which at least one or more elongated holes are provided. For the purpose it is advantageous that the raised formations or structure elements forming the outer side of the drum jacket together with the lands situated therebetween form lower areas in which elongated holes are provided. The raised formations or structure elements corresponding to the outer side of the drum form the background area on the future visible side of the fleece material, while corresponding raised formations are formed by the lower, deeper areas.
Furthermore, it is advantageous that one or more elongated holes are either provided in the lands between the raised formations of structure elements or only in the raised formations and that the long sides of the longitudinal holes or the midplanes of the holes cross the movement plane or midplane of the drum jacket at the angle β between 20° and 170° or between 40° and 160° or between 80° and 100°.
Depending on the consistency of the material or of the fleece to be processed, a reduced number of holes may be provided for dewatering purposes.
It is also advantageous that the structure elements or raised formations provided on the drum jacket are designed as longitudinal raised formations arrayed over the whole circumference of the drum jacket angularly or approximately diagonally to the circumferential direction of the drum jacket over its whole length and either form continuous structure elements or raised formations or form raised formations which are interrupted at some points. If the longitudinal raised formations are not aligned exactly relative to the movement plane of the drum jacket, but at least slightly diagonally, washing of the filaments through the holes is advantageously avoided. The results can be positively influenced by an angle β of 170° between the transverse plane and the movement plane of the drum jacket being reduced toward 90°.
It is further advantageous that the structure elements or raised formations provided on the drum jacket are made as longitudinal raised formations arranged at a spacing from the ends of the drum jacket. By means of this, a very robust drum jacket suitable for extremely long use is obtained.
It is also advantageous that the structure elements or raised formations provided on the drum jacket are realized as solid bodies.
Furthermore, it is advantageous that the structure elements or raised formations are of cubic or pyramidal shape, the raised formations each having at least one longitudinal hole and the holes provided in the depressions representing about 12% to 80% or 40% to 50% of the total surface of the respective depressions. Depending on the application or processing of the fleece, the drum jackets are installed with the described holes in order to thus optimize the dewatering of the drum jacket.
It is also advantageous that the holes, at least in the raised formations and structure elements and/or in the lands are arranged approximately parallel to, or oriented in or diverging from the direction of the outer surface of the drum jacket.
It is also advantageous that the structure elements or raised formations with holes have different forms of profiles, the holes being limited by lateral elements of different dimensions and at least the biggest lateral element intersecting the movement plane or the midplane of the drum jacket at an angle β between 20° and 170° or between 40° and 160° or between 80° and 100°. The more the angle β is angled toward 90°, the less filaments pass through the holes.
In a further embodiment of the invention it is advantageous that the structure elements or raised formations have an approximately flat surface directed outward or toward the outer circumference and have different profiles in top view, the flat surface of the raised formation being approximately parallel or almost parallel to the surface of the drum jacket or one of the sieve sleeves of the drum jacket. A structure in the fleece is advantageously formed by the raised formations.
According to a preferred embodiment of the invention, the holes in the structure elements are provided with a width of between 0.1 and 1.0 mm or between 0.2 and 0.8 mm or 0.4 and 0.7 mm.
It is also advantageous that the holes in the depressions are provided at a width of between 0.2 and 1.0 mm or between 0.2 and 0.8 mm or between 0.3 and 0.7 mm or between 0.3 and 0.6 mm or between 0.4 and 0.7 mm or between 0.3 and 0.6 m or between 0.4 and 0.7 mm or between 0.5 and 0.7 mm, preferably 0.6 mm.
Moreover, it is advantageous that a lateral area of the structure elements forms an angle α of 90° together with a surface is of the structure elements.
It is also advantageous that the lateral area of the structure elements forms an angle α with the surface of the structure elements of between 90° and 30° or 90° and 40° or 90° and 50° or 90° and 60°, particularly between 90° and 80°. Furthermore it is advantageous that the profile of the longitudinal holes in the depression and/or in the raised formation is oval or polygonal, particularly hexagonal, rectangular, or triangular.
Furthermore it is advantageous that the holes in the depressions are surrounded by rims of widths smaller than the length of the hole.
In a further development of the invention it is advantageous that the holes in the depressions are surrounded by rims of widths between 0.2 and 0.88 mm, preferably between 0.3 and 0.7 mm or between 0.4 and 0.6 mm.
It is further advantageous that one flank of each structured element is rounded, while the transition between the flank of the structure element and the surface of the depression is somewhat sharp-edged. Since the structure elements have tilted flanks and are rounded at the ends, a gentle treatment of the fleece is guaranteed. The sharp-edged transitions in the area of the depression guarantee the formation of well defined relief patterns.
According to a preferred embodiment of the inventive solution it is provided that the elongated holes are of a length of between 2 and 4 mm and of a width of between 0.4 and 0.6 mm.
Further advantages and details of the invention are described in the claims and in the description and are illustrated in the figures.
a to
In
According to the illustrated embodiment shown in
According to a further illustrated embodiment not shown in the drawing, the holes 4 may also be provided only in the lands 5 between the raised formations or structure elements 2.
A fleece 13 and/or woven or knitted textile to be patterned are guided over the drum jacket 1 that has a plurality of depressions 5. Nozzle beams 14 are arranged parallel to the axis of the drum jacket 1. The underside of each nozzle beam 14 has a nozzle strip, which is not shown in the drawing, by means of which water jets 12 are ejected. The water is drawn off by a suction tube 17 schematically indicated in the drawing. For this purpose, the holes 3 and 4 are provided in the raised formations or structure elements 2 and in the lands 5, as will be explained in detail in the following.
The holes 3 and/or 4 of the drum jacket 1 can be provided with differently shaped profiles of the same or of different sizes. Longitudinal sides or side elements 3.1 and 4.1 or midplanes 3.3 and 4.3 of the holes 3 and 4 intersect the movement plane or midplane 10 of the drum jacket 1 at an angle β between 20° and 170° or between 40° and 160° or between 80° and 100°.
The structure elements or raised formations provided on drum jacket 1 are realized as longitudinal structure elements or raised formations 2 arrayed over the whole surface of the drum jacket extending angularly or approximately diagonally to the rotation direction of the drum jacket over its whole length and form either continuous structure elements or individual raised formations and/or raised formations that are interrupted at some points. The raised formations are spaced from the ends of the drum jacket 1. Moreover, the structure elements or raised formations 2 provided on the drum jacket 1 can be made as solid bodies or also as hollow bodies according to a further embodiment that is not shown.
In the illustrated embodiment, the holes 3 and/or 4 are elongated, oval or polygonal, particularly hexagonal, rectangular or triangular and have the longitudinal side 4.1.
A good dewatering result is also obtained by the fact that the longitudinal sides 4.1 or the midplanes 4.3 of the holes extend diagonally to the movement plane. The movement plane 10 shown in
The angle β formed between the movement plane or the cross-section plane 10 of the drum jacket 1 and the longitudinal sides or the lateral elements 3.1 and 4.1 or the midplanes 3.3 and 4.3 of the holes 3 and/or 4 is between 20° and 170° or between 40° and 160° or between 80° and 100°.
The structure elements or raised formations 2 have approximately flat faces 2.1 directed radially outward and have different shapes in top view, the flat face 2.1 of the raised formation 2 being approximately parallel or almost parallel to the outer surface of the drum jacket 1 or of the sieve sleeve 1.1 of the drum jacket 1.
A coarse-mesh backing fabric 11 and a spun-lace cylinder 16 permeable to fluid may be provided inside the drum jacket 1.
As can be seen particularly from
As can be further seen from
The structure elements 2 can have different shapes in top view designed according to the shapes to be formed in the fleece surface. The profile shape can be straight, oval or polygonal, particularly hexagonal, rectangular or triangular.
The holes 3 provided in the structure elements 2 have a width of between 0.1 and 1 mm or between 0.2 and 8 mm or between 0.4 and 0.7 mm. As can be seen particularly from FIGS. 3 to 5, the depressions 5 are also provided with a plurality of holes 4 arranged side by side. It is also possible, however, to provide two or more holes in the depressions as dewatering holes. Furthermore, the holes can be in the depressions 5 instead of in the structure elements 2.
The profile of the hole in the depression can either be longitudinal or oval according to
The edges of the holes 4 in the depression 5 are surrounded by rims 8 of widths between 0.2 and 8 mm, preferably between 0.3 and 0.7 mm or between 0.4 and 0.6 mm.
According to
According to
The holes according to
The ratio of L:B (length:width)=20
The ratio of L:B (length:width)=2 to 50
The ratio of L:B (length:width)=2 to 40
The ratio of L:B (length:width)=2 to 30
The ratio of L:B (length:width)=2 to 25
The ratio of L:B (length:width)=2 to 15
The result of the dewatering is further optimized with an increase in length of the holes 3 and 4.
The structure elements or raised formations 2 provided on the drum jacket 1 in form of longitudinal raised formations can extend over the whole circumference of the drum jacket 1 in rotation direction or extend approximately diagonally to the rotation direction of the drum jacket over its whole width and form either continuous structure elements or raised formations and/or raised formations which are interrupted at some points.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102006007834.9 | Feb 2006 | DE | national |
