EP1624099A1 - Needle for needle punching of textile fabrics - Google Patents

Abstract

A needle for surface finishing textiles has a working section (5) with at least three edges, spaced at most by 0.35 mm from each other, e.g. three or four edges or star-shaped, corresponding to at least 46 gauge. The edges have barbs (24, 25, 26) less than 0.02 mm deep. The barbs can be spaced axially in pairs or spaced along a spiral with a pitch twice the length of the barb. The edges and the barbs are rounded to a specified degree related to the dimensions of the cross-section. The end of the needle tapers towards a point (17), which has no sharp edges.

Description

The invention relates to a needle which is provided for the aftertreatment, in particular for needling of textile fabrics, such as felts, woven fabrics, knitted or the like. The aftertreatment may serve to give the fabric a different textile character e.g. to give a fluffy surface.

Fabric needling to achieve roughness on one side or on both sides of a pre-fabricated one textile fabrics are known. For example, the paper "Needling furnishing fabrics and woven fabric-reinforced textiles", Juergen M. Strössner, Gustav Wizemann, ITB International Textile Bulletin 2/2003, deals with the roughening of tissue using special tissue-friendly needles. These have an oval, teardrop-shaped cross section with a provided on a flank longitudinal edge, which carries one or more teeth for roughening the tissue. The needles are specified with a gauge of 38/40, which corresponds to a height or width of the working part cross section of more than 0.4 mm.

Furthermore, in the technical article needles for the production of velor structures with triangular working part cross-section are mentioned.

In addition, for example, from DE-OS 1 760 440 needles for felting purposes (so-called felting needles) are known which have a straight shaft with a working part formed thereon. The working part has, for example, a triangular or quadrangular cross section, which thus defines three or four longitudinal edges. Teeth are pressed in at the edges, which serve to entangle the needles contained therein during the piercing of a random fiber fabric and thus to densify the fiber structure. The hooks formed on the edges are offset from one another in the axial direction. They are relatively deep and have a projecting over the cross section of the shaft section. This gives them a high felting effect. However, such needles are little or not suitable for aftertreatment of textile fabrics, such as fabrics. They cause too much tissue damage or are completely disabled for this purpose.

From DE-OS 25 18 066 a further felting needle is known, which serves to engulf individual fibers of a loose nonwoven fabric by multiple piercing perpendicular to the nonwoven plane with each other while compacting the fiber material. The focus here is on fiber take-up capacity, which should be as high as possible. However, the fibers, i. the individual filaments are damaged as little as possible. At least in one embodiment, the needle has a triangular cross section with hooks arranged on the edges. The hooks are offset from each other. For the hooks, various embodiments are provided, both those which protrude beyond the outer contour of the working part and those which have no protrusion.

From DE 195 21 796 C1 also designated as a felt needle needle for needling a nonwoven fabric on a carrier fabric is known. By needling the nonwoven fabric is connected to the carrier fabric. The needle has a triangular cross-section bounded by three longitudinal flattened edges. In the edges axially offset notches are incorporated, which do not project beyond the outer contour and have a depth of 0.01 to 0.04 mm, preferably of 0.02 mm.

When a felting needle is pierced into a pre-bonded nonwoven fabric, into a felt or into a carrier fabric, considerable longitudinal loads on the felting needle can occur. The longitudinal loads are the more critical the slimmer the felting needle is trained. For the aftertreatment of textiles, for example, the roughening serve, but usually very fine needles are used, which have a very small cross-section. Due to the slenderness of the working part of such a needle is to be expected with a certain flexibility and in addition to the fact that the needles experience a certain lateral deflection when piercing the tissue. It should be striven that these bends do not occur uncontrolled. Particularly disadvantageous are needle breaks. Broken work pieces unduly damage the tissue in question. It is therefore difficult to make existing slim needles even slimmer.

On this basis, it is an object of the invention to provide a Nachbehandlungsnadel for textile fabrics, with a textile fabric, a florartige, hairy surface can be issued and produced at high operating speed and reliability no harmful tissue damage. This object is achieved with the aftertreatment needle according to claim 1:

The needle according to the invention has an example triangular or star-shaped cross-section, which has a dimension of 0.35 mm (gauge 46) or less due to the particularly slim design of the working part in the transverse direction. The working height of a triangular cross-section corresponds to the triangular height. In the case of a star-shaped cross section, the working height is measured over all four edges. At least two edges have adjacently arranged notches whose depth is 0.02 mm or less. Preferably, all three edges are provided with such notches, these notches then being on one to the longitudinal central axis of the working part concentric circle or a helix whose pitch is less than three times the axial length of a notch. Preferably, the pitch is even less than twice the axial length of a notch. By this measure, in conjunction with the small depth of the notches is achieved that unilateral asymmetric weakening of the working part can be avoided, as they may occur in staggered notches. When piercing the slender post-treatment needle in solid fabric or precompressed nonwoven, it does not lead to uncontrolled lateral buckling of the working parts of the individual needles. Thus, the working speed can be increased, the needle shows a high overall load capacity. On the other hand, the notches lying on a common rim form a certain weakening of the working part in the sense that a point with increased spring elasticity is determined. The aftertreatment needle is therefore less susceptible to needle breakage due to lateral distortion of the textile fabric.

The cross-sectional shape of the aftertreatment needle, due to its small width of only 0.35 mm or less, can not readily be obtained by scaling down existing needle cross-sections of coarser needles. Rather, the rounding radii present at the longitudinal edges must be adjusted with respect to the cross section so that they do not form sharp edges that cut through the threads of the fabric. The radii of curvature of the longitudinal edges are preferably greater than one third of the radius of a circumference around the cross section of the working part of the needle. Under "perimeter" is understood to mean a circle whose center lies on the longitudinal central axis of the working part, and which strips the edges of the working part. In a further preferred embodiment, the radii of the edges are greater than half the radius of the circumference around the cross section of the working part of the needle. The result is a heavy duty stiff but very slim needle, which shows a very low tissue damage.

Preferably, the tip of the needle body is formed almost punctiform at the pointing away from the chucking end of the working part. The radius of curvature is preferably below one hundredth of a millimeter. The needle body is preferably evenly curved after this tip and provided with no edges or facets or the like. This ensures that the needle penetrating through a tissue can also pierce individual threads without displacing them laterally. This reduces on the one hand the load on the needle and on the other hand causes a reduction of the lateral distortion of the tissue. In addition, damage to the threads is avoided.

The notches are preferably formed so that no part projects beyond the outer contour of the working part defined by the circumference. Preferably, no part is beyond the actual cross-sectional contour of the working part over. The notches are rounded in the transition to the working part. Their radius of curvature is preferably even greater than the radius of curvature of the longitudinal edges. It is preferably about as large as the radius of curvature of the circumference but not greater than this. This, in conjunction with the shallow depth of the notches, reduces the cross-section by less than 10% in the area of the three notches lying at the same height.

Further details of advantageous embodiments of the invention will become apparent from the drawings, the description or claims.

Figur 1

eine erfindungsgemäße Nachbehandlungsnadel in vergrößerter Darstellung in Seitenansicht,

Figur 2

die Nadel nach Figur 1 in einer ausschnittsweisen, stark vergrößerten Seitenansicht,

Figur 3

die Nadel nach Figur 1 und 2 in einer perspektivischen, ausschnittsweisen Ansicht,

Figur 4

einen Querschnitt durch eine erste Ausführungsform eines Arbeitsteils einer erfindungsgemäßen Nadel in schematisierter Darstellung,

Figur 5

einen weiteren Querschnitt durch eine andere Ausführungsform eines Arbeitsteils einer erfindungsgemäßen Nadel in schematisierter Darstellung,

Figur 6

eine abgewandelte Ausführungsform einer erfindungsgemäßen Nadel in schematisierter Seitenansicht,

Figur 7

einen weiteren Querschnitt durch eine Ausführungsform des Arbeitsteils einer erfindungsgemäßen Nadel in schematisierter Darstellung und

Figur 8

einen Querschnitt durch ein vierkantiges Arbeitsteil einer erfindungsgemäßen Nadel in schematisierter Darstellung.

In the drawings, embodiments of the invention are illustrated. Show it:

FIG. 1

an aftertreatment needle according to the invention in an enlarged view in side view,

FIG. 2

the needle of Figure 1 in a fragmentary, greatly enlarged side view,

FIG. 3

the needle of Figure 1 and 2 in a perspective, fragmentary view,

FIG. 4

a cross section through a first embodiment of a working part of a needle according to the invention in a schematic representation,

FIG. 5

a further cross-section through another embodiment of a working part of a needle according to the invention in a schematic representation,

FIG. 6

a modified embodiment of a needle according to the invention in a schematic side view,

FIG. 7

a further cross-section through an embodiment of the working part of a needle according to the invention in a schematic representation and

FIG. 8

a cross section through a four-sided working part of a needle according to the invention in a schematic representation.

FIG. 1 illustrates a needle 1 serving as a post-treatment needle, whose needle body 2 has a straight shaft 3. This is provided at its one end with an example cylindrical clamping part 4. At its opposite end a working part 5 is formed. The working part 5 is integrally connected to the clamping part 4.

The working part 5 is designed to be particularly slim. In the present embodiment, it has a triangular cross section whose height is 0.35 mm or less. The length of the working part 5, however, exceeds, at least preferably, a value of 10 mm. A plurality of edges 6, 7, 8, which are illustrated separately in FIG. 4, are formed on the working part, each having a rounding radius R. The rounding radius R is preferably the same for all three edges 6, 7, 8. It is at least so large that the edges 6, 7, 8 can not be considered as sharp and are not able, when quickly inserting the working part 5 in an existing fabric or a felt or other textile fabric, existing filaments or even existing threads, such as threads to sever. Preferably, the radius of curvature R is greater than at least one third of the radius Ru of a circumference 9, which is shown in dashed lines in Figure 4 and touches all three edges 6, 7, 8. This perimeter 9 is concentric with an imaginary longitudinal central axis 11 of the working part 5.

The cross section shown in FIG. 4 has a lateral extent determined by its circumference 9, which is smaller than the lateral extent of the cross sections of existing felting needles. The distance between the edges 6, 7; 7, 8; 8, 6 from each other is considered as a cross-sectional width or cross-sectional height. It is preferably 0.35 mm or smaller. Thus, the inventive very fine needle 1 in a textile fabric, such as a fabric or a fine felt, barely visible puncture holes on the insertion side or carrying side.

The needle 1 has in particular from Figure 2, 3 and 4 apparent notch 12, 13, 14, which, as Figure 2 for the notches 12, 13 indicates, based on the longitudinal central axis 11 are arranged in the same axial position. They lie on a common wreath or circle around the longitudinal center axis 11 and are formed equal to each other. To illustrate, the notch 12 is shown separately in Figure 3. It has an asymmetrical saddle surface 15, which forms a tooth 16 at its end facing the clamping part 4. This has no over the outer contour protruding portion. The outer contour is formed in Figure 4 by the cross-section bounding triangle with rounded corners. The depth of the notch 12 is preferably equal to or less than 0.02 mm. The saddle surface 15 is taken in its section according to Figure 4 at its lowest point and shown in dashed lines at this point. The radius of curvature Rs of the saddle surface may correspond approximately to the radius of curvature of the circumference 9. In this case, the centers of curvature of the radii of curvature of the saddle surfaces of the triangular notches 6, 7, 8 are in the vicinity of the center about the central axis 11, i. within a range of, for example, 0.1 mm around them.

The notches 12, 13, 14 are arranged at a distance from a tip of the working part 5. This distance is preferably a few millimeters and is for example in in the range of 2 to 5 mm. The tip 17 is preferably pointed in the literal sense, ie its radius of curvature is at most about 1/100 mm. At this sharp tip 17, the outer surface of the pointed portion 18 connects, which is free of edges, facets or similar features. Rather, it is smooth, ie in particular formed edgeless. At the edge region 18, the flat side surfaces 21, 22, 23 of the approximately triangular working part 5 also run out. This is illustrated in Figure 2 for the side surface 21.

Apart from the notch rim 24 formed by the notches 12, 13, 14, more notching rings 25, 26 may be provided from such notches, as shown in FIG. 1, in order to extract a larger number of fleece threads from the tissue plane with a single puncture through an existing tissue , The notched rings 24, 25, 26 act to a lesser extent as spring points that allow lateral flexible yielding of the slim working part 5 without damaging it. In addition, they symmetrize the forces during insertion of the slim working part by solid tissue, so that the working part 5 does not buckle laterally.

FIG. 5 illustrates a modified embodiment of a needle 1 on the basis of its cross section. This is in the broadest sense star-shaped, the individual points or wings of the star are rounded outside with a large radius of curvature R. As a result, the edges 6, 7, 8 are not sharp despite the high fineness of the working part 5. The working part 5 has in the usual Gaugemaß for felting needles, which normally only needles up to gauge 43, a measure that corresponds to the gauge 46. This is the diameter of the circumference 9 not greater than 0.35 mm. Its radius Ru is thus not greater than 0.175 mm. The radius of curvature R is preferably greater than 0.5 mm, more preferably a radius greater than 0.06 mm. In a particularly preferred embodiment, it is greater than 0.09 mm, ie greater than half of the radius Ru. This allows on the one hand to achieve very small stitch holes and on the other hand avoid thread damage even at high speeds. Furthermore, it also applies here that the individual notches 12, 13, 14 have a depth of at most 0.02 mm, with no tooth sections projecting beyond the outer contour of the cross section and certainly not beyond the circumference 9. The saddle surface 15 of each notch 12, 13, 14 has a radius Rs between 0.1 and 0.175 mm. The center of curvature is preferably in the vicinity of the longitudinal central axis 11 or on the same. Preferably, it lies in a zone around the central axis 11 whose radius is less than 0.05 mm.

FIG. 6 illustrates a further embodiment of the needle 1, the working part 5 of which may have the triangular cross section according to FIG. 2 or the star-shaped cross section according to FIG. The notches 12, 13 and the other not separately designated notches are the same length in the axial direction and otherwise the same. They preferably have a length of at most 12/100 mm. In the axial direction adjacent notches 12, 13 are offset from each other on the helical line. The offset V is in the range of 10/100 to 7/100 mm. It is preferably slightly less than the length K of each notch, which is preferably about 12/100 mm. Thus, the distance between adjacent notches arranged at a common edge 6 is, for example, at most 30/100 mm. For a needle with four edges, this distance is then a maximum of four times the offset, ie at most 40/100 mm. This distance coincides with the pitch G of the helix on which the notches are located. Thus, the pitch G is equal to or less than three times the length K of each notch. Preferably, the pitch G is even less than twice the length K. If the axial spacing of the notches 12, 13 and the other notches following the helix is only 7/100 mm, the pitch G of a working part with triangular cross-section is 21/100 mm less than twice the notch length K of 12/100 mm.

In this helical configuration of the notches illustrated in FIG. 6, these form an annular area around the working part 5, which is shorter than 1 mm overall and whose distance from the tip 17 is preferably about 2 mm. Above and below this area, the working part 5 is preferably smooth. The restriction of the notches to a narrow annular area and the smooth formation of the working part 5 above and below this area is also advantageous in all other embodiments. It has been shown that with such needles, a particularly gentle after-treatment process can be represented. In particular, the needles need not be very deeply stung by the fabric or knit or other textile. The friction between the edges 6, 7 and the existing fibers is reduced to a minimum. This opens the way to further slimming the needles. By the compression of the notches on a short work area with a length which is less than 1 mm and which is arranged in the immediate vicinity of the tip 17, a short-stroke operation of the needles 1 is possible. The danger of that by further Slimming of the working part 5 entering sharpening of the edges 6, 7 damage the threads of the textile fabric is thereby reduced.

• • einen weicheren textilen Charakter,
• • eine florartige, haarige Oberfläche,
• • einen besseren Tragekomfort - es kann ein weicherer Stoff ausgebildet werden,
• • deutlich reduziertes Ausfransen,
• • eine höhere Dimensionsstabilität,
• • eine höhere Reißfestigkeit,
• • eine höhere Weiterreißkraft, wobei als Weiterreißkraft die Kraft bezeichnet wird, die notwendig ist, um ein eingeschnittenes Textil weiter aufzureißen.

The needle according to the invention is used, for example, for re-needling of woven, knitted or crocheted fabrics. By Nachnadeln receives the fabric, at least some of the following properties:

• • a softer textile character,
• • a florish, hairy surface,
• • better wearing comfort - a softer fabric can be formed,
• • significantly reduced fraying,
• A higher dimensional stability,
• A higher tensile strength,
• • a higher tearing force, which is the tearing force, the force that is necessary to further tear a cut fabric.

In addition, due to the surface treatment, the bonding strength to any coating material, such as latex, is increased.

Due to the fineness of the inventive needle 1 with gauge at least 46, and the small depth of the notches of only 0.02 mm, the risk of thread injury or fiber damage is reduced to a minimum. This avoids material distortion and training to large stitch holes. The arrangement of the notches in each case at least in pairs or in groups of three at the same height symmetrizes in the particular slender needle 1 occurring forces and prevents kinking when working fast or heavy tissues.

FIGS. 7 and 8 illustrate further preferred cross-sectional shapes of the working part 5. The working part 5 according to Figure 7 has three edges 6, 7, 8, which are flattened so far that they appear radially seen from the outside as narrow strips. Its radius of curvature R is preferably greater than its distance from the longitudinal center axis 11. It is also possible that the radius of curvature is almost infinite, so that it is a flat strip. Between the strip-shaped edges 6, 7, 8 flat side surfaces 21, 22, 23 are arranged. The transitions between the side surfaces 21, 22, 23 and the edges 6, 7, 8 are defined by linear edge regions, i. Creasing edges 27, 28, 29, 30, 31, 32 formed. The notches 12, 13, 14 are indicated by dashed lines in FIG. With regard to their depth and arrangement, the above statements apply.

The illustrated in Figure 8 working part 5 is formed square. Its edges 6, 7, 8, 10 are arranged at the corners of a star. The radius R of these strip-shaped edges is preferably as large as the distance to the longitudinal central axis 11 or larger, it can also be infinite. If necessary, however, these edges 6, 7, 8, 10 may also be rounded. The between the edges 6, 7, 8, 10 in pairs enclosed side surfaces 20, 21, 22, 23 define concave outer sides. In a preferred embodiment, they each consist of two mutually obtuse angle strip-shaped surface areas. In a particular embodiment, the outsides have a straight surface area that is not curved is. All four edges 6, 7, 8, 10 are each provided with notches, which are preferably arranged on a helix of low pitch. The pitch of the corresponding helix is here preferably less than four times the axial length of a notch.

A needle 1 according to the invention is used for the aftertreatment, for example post-needling of existing textile fabrics, for example for roughening the surface. The needle 1 is bezügl. the longitudinal central axis 1 is formed completely symmetrical, which also applies in particular with regard to their notches 12, 13, 14. It has a gauge of at least 46 and a notch depth of at most 0.02 mm. It allows gentle, productive work and the production of particularly fine textiles.

LIST OF REFERENCE NUMBERS

1

needle

2

needle body

3

shaft

4

chucking

5

working part

6, 7, 8, 10

edge

9

perimeter

11

Longitudinal central axis

12, 13, 14

notch

15

saddle surface

16

tooth

17

top

18

tip area

20, 21, 22, 23

faces

24, 25, 26

notch wreaths

27, 28, 29, 30, 31, 32

creases

G

pitch

K

length

V

offset

R

rounding radius

Ru

Radius radius

Rs

Rounding radius of the saddle surface

Claims (12)

Aftertreatment needle (1) for textile fabrics,
with an elongate needle body (2) elongated with respect to an axial direction, having at one end a chucking part (4) and at its other end a working part (5) having a number n of edges (6, 7) arranged in the axial direction of the needle body (2) , 8, 10) and has a cross-sectional height of less than 0.35 mm, the number n being equal to or greater than three,
with notches (12, 13) disposed adjacent to at least two edges (6, 7), the adjacent notches (12, 13) having a depth less than 0.02 mm and arranged in pairs in the same axial position or on a helical line are whose pitch (G) is less than n times the length of the notch (12). Aftertreatment needle according to claim 1, characterized in that the pitch (G) is less than twice the length of the notch (12). Post-treatment needle according to claim 1, characterized in that the working part (5) has a star-shaped cross-section. Aftertreatment needle according to claim 1, characterized in that the working part (5) has a triangular or quadrangular cross-section. Post-treatment needle according to claim 1, characterized in that the edges (6, 7, 8, 10) are rounded. Nachbehandlungsnadel according to claim 5, characterized in that the radius of curvature (R) of the edges (6, 7, 8) is greater than 1/3 of the radius (Ru) of a circumference (9) around the cross section of the working part (5) Needle (1). Aftertreatment needle according to claim 5, characterized in that the radius of curvature (R) of the edges (6, 7, 8) is greater than 1/2 of the radius (Ru) of a circumference (9) about the cross-section of the working part (5) of the needle ( 1) . Aftertreatment needle according to claim 1, characterized in that the needle body (2) has an almost punctiform tip (17) at the end pointing away from the clamping part (4). Post-treatment needle according to claim 8, characterized in that the tip (17) is formed edge-free. Aftertreatment needle according to claim 1, characterized in that all the edges (6, 7, 8) are provided with notches (12, 13, 14), the notches (12, 13, 14) being in annular or annular areas (24, 25 , 26) are arranged. Aftertreatment needle according to claim 1, characterized in that the notches (12, 13, 14) make a curvature the longitudinal central axis (11) of the working part (5) whose radius (Rs) is less than the radius (Ru) of a circumference (9) containing the cross-section of the working part (5). Aftertreatment needle according to claim 1, characterized in that the edges (6, 7, 8, 10) are formed by strip-shaped flat surface areas.

Images